Ophthalmic device and control method thereof

Abstract

To provide an ophthalmologic device capable of acquiring, in short time and easily, eye characteristics of an eye to be examined, even when eye nystagmus occurs on the eye to be examined or a subject is a child, and a control method of the same.SOLUTION: An ophthalmologic device comprises: a detecting part for detecting a relative position of an eye to be examined, to an eye characteristic acquiring part; a temporary alignment control part for performing temporary alignment of the eye characteristic acquiring part to the eye to be examined, by driving a relative movement part, on the basis of a detection result of the detecting part; a re-detecting part for causing the detecting part to execute repeatedly, detection of the relative position after completion of the temporary alignment; a determination part for, on the basis of a detection result of the detecting part before and after the temporary alignment, determining whether, the eye characteristic acquiring part approached to the eye to be examined by the temporary alignment by a predetermined threshold distance or a greater distance; and an operation mode selecting part for, on the basis of the determination result, selecting, any of a normal mode, and a quick mode, as an operation mode for acquiring the eye characteristic by the eye characteristic acquiring part and alignment of the eye characteristic acquiring part to the eye to be examined.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In ophthalmology, various eye characteristics such as the eye refractive power, intraocular pressure, and number of corneal endothelial cells of a subject's eye are acquired (measured, photographed, observed, etc.) using an ophthalmic apparatus. In this case, from the viewpoint of the precision, accuracy, and image quality of the acquired eye characteristics, it is extremely important to position the measurement head (ocular characteristic acquisition unit) of the ophthalmic apparatus relative to the subject's eye, i.e., alignment. For this reason, ophthalmic apparatuses that perform so-called full auto alignment (hereinafter simply referred to as auto alignment) are well known, in which the relative position of the subject's eye relative to the measurement head is detected and the measurement head is automatically aligned with the subject's eye based on the detection result of this relative position.

[0003] However, even in an ophthalmologic apparatus equipped with an auto-alignment function, if the subject's eye has nystagmus or if the subject is a restless child, it takes time to properly align the measurement head with the subject's eye. Furthermore, particularly when measuring the ocular refractive power of the subject's eye as an ocular characteristic, it takes time to measure the ocular refractive power of a subject with nystagmus or a restless child because it is difficult for the subject to continue looking at a fixation target for a certain period of time.

[0004] The ophthalmologic apparatus described in Patent Document 1 has two operating modes for measuring the ocular refractive power of the subject's eye: a normal measurement mode for performing normal ocular refractive power measurement, and a continuous measurement mode for performing continuous ocular refractive power measurement. The continuous measurement mode is a mode for quickly and continuously measuring ocular refractive power by omitting the known provisional measurement (preliminary measurement) and automatic fogging that are performed in the normal measurement mode.

[0005] The ophthalmologic apparatus described in Patent Document 1 switches the operating mode to a continuous measurement mode in response to a mode switching operation by the examiner or when ocular refractive power measurement in the normal measurement mode fails, and measures the ocular refractive power of the subject's eye. This allows for continuous measurement of ocular refractive power until the required ocular refractive power measurement result is obtained, even if the subject's eye has nystagmus or if the subject is a child. As a result, appropriate ocular refractive power measurement can be performed for each subject. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-208590 Summary of the Invention [Problem to be solved by the invention]

[0007] In the ophthalmologic apparatus described in Patent Document 1, if nystagmus occurs in the subject's eye or if the subject is a child, the examiner must switch the operation mode of the ophthalmologic apparatus to continuous measurement mode, which is time-consuming. Also, in the ophthalmologic apparatus described in Patent Document 1, if eye refractive power measurement in normal measurement mode fails, the operation mode is switched to continuous measurement mode, but in this case, the eye refractive power measurement in normal measurement mode becomes useless, which is a problem that takes extra time.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide an ophthalmic apparatus and a control method thereof that can acquire the eye characteristics of the subject's eye simply and quickly, even when the subject has nystagmus or is a child. [Means for solving the problem]

[0009] An ophthalmologic apparatus for achieving the object of the present invention includes an ophthalmic characteristic acquisition unit for acquiring ocular characteristics of a subject's eye, a relative movement unit for moving the ocular characteristic acquisition unit relative to the subject's eye, a detection unit for detecting the relative position of the subject's eye relative to the ocular characteristic acquisition unit, a temporary alignment control unit for driving the relative movement unit to perform temporary alignment of the ocular characteristic acquisition unit with the subject's eye based on the detection result of the detection unit, a re-detection unit for repeatedly executing detection of the relative position by the detection unit after completion of the temporary alignment, a determination unit for determining whether the ocular characteristic acquisition unit has come closer to the subject's eye by a distance equal to or greater than a predetermined threshold based on the detection result of the detection unit before and after the temporary alignment, and a determination unit for determining the alignment of the ocular characteristic acquisition unit with the subject's eye and the correction of the ocular characteristics by the ocular characteristic acquisition unit based on the determination result of the determination unit. The device comprises an operation mode selection unit that selects either a normal mode or a quick mode, which is simpler than the normal mode, as the operation mode for acquisition; an alignment control unit that drives the relative movement unit to perform alignment in the operation mode selected by the operation mode selection unit based on the detection result of the detection unit after completion of temporary alignment; and a measurement control unit that causes the eye characteristic acquisition unit to acquire eye characteristics in the operation mode selected by the operation mode selection unit after completion of alignment.The operation mode selection unit selects the normal mode as the operation mode for both alignment and acquisition of eye characteristics if the judgment unit determines that the eyes have approached by a distance equal to or greater than a threshold, and performs a first selection process that selects the quick mode as the operation mode for at least one of the two if the judgment unit determines that the eyes have approached by a distance equal to or greater than a threshold.

[0010] According to this ophthalmologic apparatus, an operation mode for obtaining alignment and eye characteristics suitable for the subject's eye (subject) can be automatically selected.

[0011] In an ophthalmologic apparatus according to another aspect of the present invention, the temporary alignment control unit is capable of performing temporary alignment based on the detection result of the detection unit after completion of the temporary alignment, and includes a repeat control unit that performs repeat control to repeatedly operate the temporary alignment control unit, the re-detection unit, and the determination unit one or more times after a first determination by the determination unit, and the operation mode selection unit, when the repeat control is performed, performs a second selection process instead of the first selection process, in which the operation mode selection unit selects the quick mode as at least one of the operation modes when the number of determinations made by the determination unit that are negative reaches a predetermined number, and selects the normal mode as both operation modes when the number of repetitive controls reaches a predetermined upper limit without the number of determinations reaching the predetermined number. This makes it possible to automatically select an operation mode for alignment and acquisition of eye characteristics that is more suitable for the subject's eye (examinee).

[0012] 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 relative movement unit that moves the ocular characteristic acquisition unit relative to the subject's eye, a detection unit that detects the relative position of the subject's eye relative to the ocular characteristic acquisition unit, a first determination unit that determines whether the position of the ocular characteristic acquisition unit is within an allowable range of an alignment position of the ocular characteristic acquisition unit relative to the subject's eye based on the detection result of the detection unit, a second determination unit that determines whether a transition flag is established to transition at least one of the operation modes of alignment of the ocular characteristic acquisition unit with the subject's eye by the relative movement unit and acquisition of the ocular characteristics by the ocular characteristic acquisition unit from a normal mode to a quick mode that is simpler than the normal mode when the second determination unit determines that the position is not within an allowable range, and In this case, the system is provided with an alignment control unit that drives the relative movement unit to perform alignment in normal mode based on the detection result of the detection unit; a repeat control unit that repeatedly operates the detection unit, the first judgment unit, the second judgment unit, and the alignment control unit until the first judgment unit determines that it is within the allowable range or until the second judgment unit determines that the transition flag is established; a normal mode control unit that causes the eye characteristic acquisition unit to acquire eye characteristics in normal mode when the first judgment unit determines that it is within the allowable range; and a quick mode control unit that causes the alignment control unit and the eye characteristic acquisition unit to perform at least one of the alignment and the eye characteristic acquisition in quick mode when the second judgment unit determines that the transition flag is established.

[0013] According to this ophthalmologic apparatus, alignment and acquisition of eye characteristics can be automatically performed in an operation mode suited to the subject's eye (subject).

[0014] In another aspect of the ophthalmic device of the present invention, the second judgment unit counts the number of alignments performed by the alignment control unit and determines whether the transition flag is established or not based on whether the number of alignments has reached a predetermined number.

[0015] In another aspect of the ophthalmic device of the present invention, the second judgment unit performs a process of detecting the distance from the eye characteristic acquisition unit to the test eye each time the detection unit detects the relative position, and a process of counting the number of times the distance exceeds a predetermined threshold, and judges whether a transition flag is established or not based on whether the number of times the threshold is exceeded has reached a predetermined number.

[0016] In another aspect of the ophthalmologic device of the present invention, the second judgment unit calculates the variance in the relative position detection results over multiple times each time the detection unit detects the relative position, and determines whether the transition flag is established or not based on whether the variance is greater than a predetermined threshold value.

[0017] A control method for an ophthalmologic apparatus for achieving the object of the present invention includes a detection step of detecting a relative position of the eye to be examined with respect to an eye characteristic acquisition unit that acquires eye characteristics of the eye to be examined; a temporary alignment step of moving the eye characteristic acquisition unit relative to the eye to perform temporary alignment of the eye characteristic acquisition unit with the eye to be examined based on the detection result of the detection step; a re-detection step of repeatedly executing the detection step after completion of the temporary alignment; a determination step of determining whether the eye characteristic acquisition unit has come closer to the eye to be examined by a distance equal to or greater than a predetermined threshold value as a result of the temporary alignment based on the detection result of the detection step; and a normal mode and a normal mode as operation modes for aligning the eye characteristic acquisition unit with the eye to be examined and acquiring the eye characteristics by the eye characteristic acquisition unit based on the determination result of the determination step. the operation mode selection step selects either the normal mode or a quick mode which is simpler than the standard mode; an alignment step in which the eye characteristic acquisition unit is moved relative to the eye to be examined based on the detection result of the detection step after completion of the provisional alignment, thereby performing alignment in the operation mode selected in the operation mode selection step; and an eye characteristic acquisition step in which, after completion of alignment, the eye characteristic acquisition unit is caused to acquire eye characteristics in the operation mode selected in the operation mode selection step. The operation mode selection step executes a first selection process in which, if it is determined in the determination step that the eyes have approached by a distance equal to or greater than a threshold, the normal mode is selected as the operation mode for both alignment and eye characteristic acquisition, and, if it is determined in the determination step that the eyes have approached by a distance equal to or greater than a threshold, the quick mode is selected as the operation mode for at least one of the two.

[0018] A control method for an ophthalmologic apparatus for achieving the object of the present invention includes a detection step of detecting a relative position of the eye to be examined with respect to an eye characteristic acquisition unit that acquires eye characteristics of the eye to be examined, a first determination step of determining whether the relative position detected in the detection step is within an allowable range of an alignment position of the eye characteristic acquisition unit with respect to the eye to be examined, a second determination step of determining whether a transition flag is established to transition at least one of the operation modes of alignment of the eye characteristic acquisition unit with respect to the eye to be examined and acquisition of eye characteristics by the eye characteristic acquisition unit from a normal mode to a quick mode that is simpler than the normal mode, if the second determination step determines that the relative position is not within an allowable range, and The method includes an alignment step of relatively moving the acquisition unit to perform alignment in normal mode, a repeating step of repeatedly performing the detection step, the first determination step, the second determination step, and the alignment step until the first determination step determines that the result is within the allowable range or the second determination step determines that a transition flag is established, a normal mode control step of causing the eye characteristic acquisition unit to acquire eye characteristics in normal mode if the first determination step determines that the result is within the allowable range, and a quick mode control step of causing at least one of the alignment and the acquisition of eye characteristics by the eye characteristic acquisition unit to be performed in quick mode if the second determination step determines that the transition flag is established. [Effects of the Invention]

[0019] The present invention makes it possible to easily and quickly obtain the eye characteristics of the subject's eye even when the subject has nystagmus or when the subject is a child. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a side view of an ophthalmologic apparatus according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of a measuring head and a control device according to the first embodiment. [Figure 3] 4 is a flowchart showing a flow of a reflex measurement process of an eye to be examined by the ophthalmologic apparatus of the first embodiment. [Figure 4] FIG. 10 is a block diagram showing a schematic configuration of an ophthalmologic apparatus according to a second embodiment. [Figure 5] 10 is a flowchart showing a flow of a reflex measurement process of an eye to be examined by an ophthalmologic apparatus according to a second embodiment. [Figure 6] FIG. 10 is a block diagram showing a schematic configuration of an ophthalmologic apparatus according to a third embodiment. [Figure 7] 10 is a flowchart showing a flow of a reflex measurement process of an eye to be examined by an ophthalmologic apparatus according to a third embodiment. [Figure 8] 10 is a flowchart showing the flow of a normal mode measurement process in the ophthalmologic apparatus 10 according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] [First embodiment] Fig. 1 is a side view of an ophthalmic apparatus 10 according to a first embodiment. As shown in Fig. 1, the ophthalmic apparatus 10 is an autorefractometer, an autorefractometer, or the like that measures at least the ocular refractive power (hereinafter referred to as "ref measurement") as an ocular characteristic of the subject's eye E. The ophthalmic apparatus 10 includes a base 12, a face support 13, a stand 14, a drive mechanism 15, and a measurement head 18.

[0022] In the figure, the X direction is the left-right direction (the interpupillary direction of the subject's eye E) based on the subject, the Y direction is the up-down direction, and the Z direction is the front-to-back direction (also called the working distance direction) that is parallel to the front direction approaching the subject (subject's eye E) and the back direction moving away from the subject.

[0023] The face support portion 13 is provided integrally with the base 12 at a position on the front side in the Z direction of the measurement head 18. This face support portion 13 has a chin rest 13a and a forehead rest 13b whose positions can be adjusted in the Y direction, and supports the face of the subject.

[0024] The platform 14 is provided on the base 12 and is movable in the XZ directions (front-back and left-right directions) relative to the base 12. A measuring head 18 and an operating lever 16 are provided on the platform 14.

[0025] The drive mechanism 15 corresponds to the relative movement unit of the present invention and holds the measurement head 18 movably in each of the X, Y, and Z directions. Although not shown, the drive mechanism 15 is configured with a known actuator that moves the measurement head 18 in each of the X, Y, and Z directions, and moves the measurement head 18 in each of the X, Y, and Z directions. This enables automatic alignment of the measurement head 18 in the X, Y, and Z directions with respect to the subject's eye E by driving the drive mechanism 15 under the control of a control device 20 described below. In addition, manual alignment of the measurement head 18 in the X, Y, and Z directions with respect to the subject's eye E can be achieved by driving the drive mechanism 15 in accordance with the operation of an operating lever 16 described below.

[0026] The operating lever 16 is provided on the stand 14, and is an operating member that is operated to move the measurement head 18 in each direction of the X, Y, and Z axes. For example, when the operating lever 16 is tilted in the Z direction (front-back direction) or the X direction (left-right direction), the driving mechanism 15 moves the measurement head 18 in the Z direction or the X direction. When the operating lever 16 is rotated around its longitudinal axis, the driving mechanism 15 moves the measurement head 18 in the Y direction (up-down direction) according to the direction of the rotation. A measurement button is provided at the top of the operating lever 16 to start reflex measurement of the subject's eye E using the ophthalmologic apparatus 10.

[0027] The measurement head 18 corresponds to the eye characteristic acquisition unit of the present invention, and has a function of measuring the refraction of the subject's eye E. Inside the measurement head 18, various optical systems corresponding to the refraction measurement are provided.

[0028] The monitor 17 is, for example, a touch panel type liquid crystal display device, and is provided on the rear surface in the Z direction of the measurement head 18. This monitor 17 displays an observation image of the anterior segment of the subject's eye E used for aligning the measurement head 18, etc., measurement results of the ocular refractive power of the subject's eye E obtained by the measurement head 18, an input screen for performing operations (settings) related to the refractive measurement, etc.

[0029] Fig. 2 is a block diagram showing a schematic configuration of the measurement head 18 and the control device 20 of the first embodiment. As shown in Fig. 2, the measurement head 18 is provided with a fixation target projection optical system 22, an observation optical system 24, an alignment optical system 26, a pattern light projection optical system 28, and a measurement optical system 30. Note that the detailed configuration of each optical system is well known, so a detailed description will be omitted here.

[0030] The fixation target projection optical system 22 projects target light of a fixation target onto the fundus of the subject's eye E in order to fixate or cloud the subject's eye E. The observation optical system 24 is an anterior segment camera that observes the anterior segment of the subject's eye E, and outputs an observation image (image data) obtained by photographing this anterior segment to the control device 20. As a result, the control device 20 displays the observation image of the anterior segment on the monitor 17.

[0031] The alignment optical system 26 is provided to detect the relative position of the measurement head 18 with respect to the subject's eye E. This alignment optical system 26 projects various types of alignment index light (bright spot images, etc.) toward the subject's eye E. As a result, the return light of the alignment index light reflected by the cornea of ​​the subject's eye E is imaged by the observation optical system 24. Then, based on the image (image data) of the return light obtained by the observation optical system 24, manual alignment is performed by the examiner or auto-alignment is performed by the control device 20. In this embodiment (the same applies to the second embodiment and subsequent embodiments described below), auto-alignment is performed as alignment.

[0032] The patterned light projection optical system 28 projects a ring-shaped patterned light onto the fundus of the subject's eye E. As a result, fundus reflection light of the patterned light projected onto the fundus of the subject's eye E is received by the measurement optical system 30. The shape of this fundus reflection light is distorted by the ocular refractive power of the subject's eye E.

[0033] The measurement optical system 30 captures (receives) the fundus reflection light of the pattern light from the fundus of the subject's eye E using an imaging element, and obtains a captured image (image data) of the fundus reflection light. This captured image includes a ring image. The measurement optical system 30 then outputs the captured image of the fundus reflection light to the control device 20.

[0034] The control device 20 includes an arithmetic circuit configured with various processors, memories, etc. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing unit (DSP), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The various functions of the control device 20 may be realized by a single processor, or may be realized by multiple processors of the same or different types.

[0035] The control device 20 is connected to the drive mechanism 15, the operating lever 16, the monitor 17, and each optical system in the measurement head 18. The control device 20 controls the drive mechanism 15 and each optical system in the measurement head 18 to perform auto-alignment and reflex measurement.

[0036] Furthermore, prior to the above-described auto-alignment and reflex measurement, the control device 20 automatically selects an operation mode for auto-alignment and reflex measurement suitable for the subject's eye E (subject), and executes the auto-alignment and reflex measurement according to the selected operation mode. The operation modes include a normal mode and a quick mode.

[0037] The quick mode is a mode in which auto-alignment and reflex measurement can be performed more easily than in the normal mode, and is suitable for reflex measurement of the subject's eye E, which suffers from nystagmus, or of restless children. Here, "simple execution" means, for example, performing alignment and reflex measurement at high speed (in a short time) by reducing the precision of the alignment and reflex measurement. Below, an example of reflex measurement and auto-alignment for each operating mode (normal mode, quick mode) will be explained.

[0038] The normal mode refractive measurement includes, for example, a provisional measurement (also called a preliminary measurement or a rough measurement) and a main measurement. The provisional measurement is performed for the purpose of properly performing cloudy vision of the subject's eye E in the main measurement, and measures the ocular refractive power of the subject's eye E while a fixation target is presented to the subject's eye E. The main measurement performs cloudy vision of the subject's eye E based on the ocular refractive power of the subject's eye E obtained in the provisional measurement, and measures the ocular refractive power of the subject's eye E in this state.

[0039] In the quick mode refractive measurement, for example, the provisional measurement is omitted (skip) and only the main measurement is performed. Unlike the main measurement in the normal mode, the quick mode main measurement measures the refractive power of the subject's eye E without performing cloud vision on the subject's eye E (cloud vision skip).

[0040] Auto-alignment in normal mode is performed before each of the provisional measurement and the main measurement. Auto-alignment in quick mode is performed before the main measurement. Furthermore, in auto-alignment in quick mode, the tolerance range (target value) of the alignment position of the measurement head 18 with respect to the subject's eye E after alignment is completed is set wider than in normal mode.

[0041] Note that even in normal mode auto alignment, the execution (realignment) before the actual measurement may be omitted. In this case, the normal mode and quick mode of auto alignment are distinguished depending on the width of the tolerance range described above.

[0042] The control device 20 executes a control program stored in a storage unit (not shown) to function as a relative position detection unit 34, a tentative alignment control unit 36, a redetection unit 38, a determination unit 40, an operation mode selection unit 42, an alignment control unit 44, a measurement control unit 46, and an ocular characteristics calculation unit 48. Note that what is described as a "unit" of the control device 20 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.

[0043] The relative position detection unit 34, together with the alignment optical system 26 and the observation optical system 24, constitutes the detection unit of the present invention. When the examiner performs an operation to start reflex measurement, the relative position detection unit 34 controls the alignment optical system 26 and the observation optical system 24 to execute a relative position detection process that detects the relative position of the subject's eye E with respect to the measurement head 18. Specifically, the relative position detection unit 34 sequentially executes the following: projection of alignment index light onto the cornea of ​​the subject's eye E by the alignment optical system 26; imaging of returned light of the alignment index light from the cornea by the observation optical system 24; and output of the captured image of the returned light from the observation optical system 24 to the relative position detection unit 34. Next, the relative position detection unit 34 detects the relative position of the subject's eye E with respect to the measurement head 18 using a known method, based on the captured image input from the observation optical system 24.

[0044] The temporary alignment control unit 36 ​​performs temporary alignment of the measurement head 18 with respect to the eye E by driving the drive mechanism 15 to move the measurement head 18 relative to the eye E based on the detection result of the relative position of the eye E by the relative position detection unit 34 (hereinafter simply referred to as the "position detection result of the relative position detection unit 34"). This temporary alignment is not particularly limited as long as it is a movement that brings the measurement head 18 relatively closer to the eye E. For example, as in normal alignment (main alignment), the measurement head 18 may be moved relatively to within an allowable range of the alignment position of the measurement head 18 with respect to the eye E, or the measurement head 18 may be moved relatively to partway along a path from the current position to within the allowable range.

[0045] After the completion of temporary alignment by the temporary alignment control unit 36, the re-detection unit 38 controls the relative position detection unit 34 to repeatedly execute the above-described relative position detection process. As a result, the relative position of the subject's eye E with respect to the measurement head 18 after completion of temporary alignment is detected by the relative position detection unit 34. Furthermore, when the normal mode is selected by the operation mode selection unit 42, which will be described in detail later, the re-detection unit 38 of this embodiment also controls the relative position detection unit 34 after the temporary measurement of the reflex measurement and before the main measurement to repeatedly execute the above-described relative position detection process.

[0046] The determination unit 40 acquires the position detection result of the relative position detection unit 34 at the start of the REF measurement (before the provisional alignment) and the position detection result of the relative position detection unit 34 after the provisional alignment is completed, that is, the position detection results of the relative position detection unit 34 before and after the provisional alignment. Then, the determination unit 40 calculates the amount of change in the relative position of the subject's eye E before and after the provisional alignment (hereinafter referred to as the amount of change in relative position) based on these position detection results. This amount of change in relative position may be calculated for each of the X, Y, and Z directions, or may be calculated using the square root of the sum of squares {R=√(X 2 +Y 2 +Z 2 )}. Next, the determination unit 40 determines whether or not the measuring head 18 has approached the subject's eye E by a distance equal to or greater than a predetermined threshold value since the temporary alignment based on the calculation result of the amount of change in relative position, and outputs the determination result to the operation mode selection unit 42.

[0047] Here, the distance threshold is determined based on the head movement distance, which is the distance that the measurement head 18 actually moves due to the temporary alignment. For example, in this embodiment, taking into consideration the error in the temporary alignment and the detection error of the relative position detection unit 34, the threshold is determined by subtracting these errors from the head movement distance.

[0048] The operation mode selection unit 42 performs a selection process (corresponding to a first selection process of the present invention) to select either the normal mode or the quick mode as the operation mode for auto-alignment and reflex measurement based on the determination result of the determination unit 40. Here, if the determination unit 40 determines that the measurement head 18 has approached the subject's eye E by a distance equal to or greater than a predetermined threshold since the temporary alignment, it is assumed that no movement has occurred in the subject's eye E while the measurement head 18 has moved the aforementioned head movement distance since the temporary alignment. Therefore, the operation mode selection unit 42 selects the normal mode as the operation mode for auto-alignment and reflex measurement.

[0049] On the other hand, if the determination unit 40 determines that the result is negative, it is assumed that movement has occurred in the subject's eye E while the measurement head 18 has moved the head movement distance described above since the provisional alignment, and it is assumed that, for example, nystagmus has occurred in the subject's eye E or the subject is a restless child. For this reason, the operation mode selection unit 42 selects the quick mode as the operation mode for auto-alignment and reflex measurement.

[0050] In this embodiment, if the determination unit 40 determines that the measurement head 18 has not approached the subject's eye E by a distance equal to or greater than a predetermined threshold value since the temporary alignment, the operation mode selection unit 42 selects the quick mode, but the present invention is not limited to this. For example, even if the distance by which the measurement head 18 has approached the subject's eye E due to the temporary alignment is greater than the head movement distance described above by a certain amount, it is assumed that movement has occurred in the subject's eye E during the temporary alignment.

[0051] Therefore, the determination unit 40 may determine whether the measurement head 18 has come closer to the subject's eye E by a distance within a predetermined threshold range (distance range) since the temporary alignment, based on the detection result of the relative position of the subject's eye E before and after the temporary alignment. In this case, the operation mode selection unit 42 selects the normal mode when the determination unit 40 determines that the measurement head 18 has come closer by a distance within the above-mentioned threshold range, and selects the quick mode when the determination unit 40 determines that the measurement head 18 has not come closer.

[0052] The alignment control unit 44 drives the drive mechanism 15 in accordance with the operation mode selected by the operation mode selection unit 42 to move the measurement head 18 relative to the eye E, thereby performing auto-alignment of the measurement head 18 with respect to the eye E. When the operation mode selection unit 42 selects the normal mode, the alignment control unit 44 performs auto-alignment before the provisional measurement of the reflex measurement (first time) based on the position detection result of the relative position detection unit 34 after the provisional alignment is completed. Furthermore, even after the provisional measurement of the reflex measurement and before the final measurement, the alignment control unit 44 performs auto-alignment before the final measurement of the reflex measurement (second time) based on the new position detection result of the relative position detection unit 34.

[0053] On the other hand, when the operation mode selection unit 42 selects the quick mode, the alignment control unit 44 performs auto-alignment before the main measurement of the reflex measurement based on the relative position detection result of the eye E by the relative position detection unit 34 after completion of the temporary alignment. In addition, at this time, the alignment control unit 44 sets the allowable range (target value) of the alignment position of the measuring head 18 with respect to the eye E after completion of the auto-alignment to be wider than in the normal mode. This makes it possible to perform auto-alignment in the quick mode more simply (less accurate but faster) than auto-alignment in the normal mode.

[0054] After the auto-alignment is completed, the measurement control unit 46 controls the fixation target projection optical system 22, the patterned light projection optical system 28, and the measurement optical system 30 in accordance with the operation mode selected by the operation mode selection unit 42 to perform a refractive measurement of the eye E. If the operation mode selection unit 42 selects the normal mode, the measurement control unit 46 starts a provisional refractive measurement of the eye E after the first auto-alignment is completed. Specifically, the measurement control unit 46 performs the following operations: presenting a fixation target to the eye E using the fixation target projection optical system 22; projecting patterned light onto the fundus of the eye E using the patterned light projection optical system 28; capturing an image of the fundus reflection of the patterned light using the measurement optical system 30; and outputting the captured image of the fundus reflection from the measurement optical system 30 to the ocular characteristic calculation unit 48. As a result, a provisional measurement value (also referred to as a preliminary measurement value or a rough measurement value) of the ocular refractive power of the eye E is obtained in the ocular characteristic calculation unit 48, which will be described later.

[0055] Next, after the second auto-alignment is completed, the measurement control unit 46 starts the main refractive measurement of the subject's eye E. Specifically, the measurement control unit 46 controls the fixation target projection optical system 22 to put the fixation target in a cloudy state based on the provisional measurement value of the ocular refractive power of the subject's eye E obtained in the provisional measurement, thereby performing clouded vision of the subject's eye E. Then, the measurement control unit 46 executes the following operations: projecting pattern light onto the fundus of the subject's eye E using the pattern light projection optical system 28; capturing the fundus reflection light of the pattern light using the measurement optical system 30; and outputting the captured image of the fundus reflection light from the measurement optical system 30 to the ocular characteristic calculation unit 48. Note that the refractive measurement (provisional measurement, main measurement) in the normal mode is a known technique, and may be performed using various known methods other than the method described above.

[0056] On the other hand, when the operation mode selection unit 42 selects the quick mode, the measurement control unit 46 skips the provisional measurement and starts the main measurement after the completion of auto-alignment. Specifically, the measurement control unit 46 executes the following operations: projection of pattern light onto the fundus of the subject's eye E by the pattern light projection optical system 28, imaging of fundus reflection light of the pattern light by the measurement optical system 30, and output of the image of the fundus reflection light from the measurement optical system 30 to the ocular characteristic calculation unit 48, while skipping the cloudy vision of the subject's eye E by the fixation target projection optical system 22. This allows the quick mode reflex measurement to be performed more simply (less accurate but faster) than the normal mode reflex measurement.

[0057] The ocular characteristic calculation unit 48 calculates the ocular refractive power (spherical power, astigmatic power, astigmatic axis angle, etc.) of the subject's eye E by a known method based on the captured image input from the measurement optical system 30 during refractive measurement of the subject's eye E. In normal mode, the ocular characteristic calculation unit 48 calculates a provisional measurement value of the ocular refractive power of the subject's eye E based on the captured image obtained in the provisional measurement, and calculates a final measurement value of the ocular refractive power of the subject's eye E based on the captured image obtained in the subsequent final measurement. In quick mode, the ocular characteristic calculation unit 48 calculates a final measurement value of the ocular refractive power of the subject's eye E based on the captured image obtained in the final measurement.

[0058] [Operation of the first embodiment] 3 is a flowchart showing the flow of a reflex measurement process of the subject's eye E by the ophthalmic apparatus 10 of the first embodiment, which relates to the control method of an ophthalmic apparatus of the present invention. As shown in Fig. 3, when the examiner performs an operation to start reflex measurement, the relative position detection unit 34 controls the alignment optical system 26 and the observation optical system 24 to execute the above-mentioned relative position detection process, and detects the relative position of the subject's eye E with respect to the measurement head 18 (step S1, which corresponds to the detection step of the present invention).

[0059] Next, the temporary alignment control unit 36 ​​drives the drive mechanism 15 based on the position detection result of the relative position detection unit 34 to perform temporary alignment of the measuring head 18 with respect to the eye E (step S2, which corresponds to the temporary alignment step of the present invention).

[0060] Then, when the temporary alignment is completed, the re-detection unit 38 repeatedly executes the relative position detection process by the relative position detection unit 34, so that the relative position detection unit 34 detects the relative position of the subject's eye E with respect to the measuring head 18 after the temporary alignment is completed (step S3, which corresponds to the re-detection step of the present invention). As a result, the relative positions of the subject's eye E before and after the temporary alignment are detected.

[0061] When detection of the relative position of the subject's eye E after completion of the temporary alignment is completed, the determination unit 40 calculates the amount of change in the relative position of the subject's eye E before and after the temporary alignment (step S4). Next, based on the calculation result of the amount of change in the relative position of the subject's eye E, the determination unit 40 determines whether the measurement head 18 has approached the subject's eye E by a distance equal to or greater than a predetermined threshold since the temporary alignment (step S5, the determination step of the present invention). This makes it possible to determine whether the subject's eye E has moved during the temporary alignment, i.e., whether nystagmus is occurring in the subject's eye E or whether the subject is a restless child. The determination unit 40 outputs the determination result to the operation mode selection unit 42.

[0062] If the judgment unit 40 judges that the measurement head 18 has approached the subject's eye E by a distance equal to or greater than a predetermined threshold since the temporary alignment (YES in step S5), the operation mode selection unit 42 selects the normal mode as the operation mode for auto-alignment and reflex measurement (step S6A). Conversely, if the judgment unit 40 judges that the measurement head 18 has approached the subject's eye E by a distance equal to or greater than a predetermined threshold (NO in step S5), the operation mode selection unit 42 selects the quick mode as the operation mode for auto-alignment and reflex measurement (step S6B). Note that steps S6A and S6B correspond to the operation mode selection step of the present invention. This makes it possible to automatically select the operation mode for auto-alignment and reflex measurement suitable for the subject's eye E (subject) prior to auto-alignment and reflex measurement.

[0063] When the operation mode selection unit 42 selects the normal mode (step S6A), the alignment control unit 44 drives the drive mechanism 15 to perform auto-alignment before the provisional measurement based on the detection result of the relative position of the test eye E after the provisional alignment is completed obtained in step S3 (step S7A).

[0064] When the auto-alignment before the provisional measurement is completed, the measurement control unit 46 controls the fixation target projecting optical system 22, the pattern light projecting optical system 28, and the measurement optical system 30 to perform provisional refractive measurement (step S8A). When this provisional measurement is completed, the ocular characteristics calculation unit 48 calculates a provisional measurement value of the ocular refractive power of the subject's eye E.

[0065] When the calculation of the provisional measurement value is completed, the re-detection unit 38 causes the relative position detection unit 34 to repeatedly execute the relative position detection process, so that the relative position detection unit 34 again detects the relative position of the subject's eye E with respect to the measurement head 18 before the actual measurement (step S9A). Next, based on the detection result of this relative position, the alignment control unit 44 drives the drive mechanism 15 to perform auto-alignment (step S10A, which corresponds to the alignment step of the present invention).

[0066] When the auto-alignment before the main measurement is completed, the measurement control unit 46 again controls the fixation target projection optical system 22, the pattern light projection optical system 28, and the measurement optical system 30 to perform the main measurement of the refractive power of the subject's eye E while performing cloudy vision of the subject's eye E (step S11A, which corresponds to the ocular characteristics acquisition step of the present invention). When the main measurement is completed, the ocular characteristics calculation unit 48 calculates the main measurement value of the ocular refractive power of the subject's eye E.

[0067] In this way, in the normal mode, the eye refractive power of the subject's eye E can be measured with high accuracy by performing normal refractive measurements (provisional measurement and main measurement).

[0068] On the other hand, when the operation mode selection unit 42 selects the quick mode (step S6B), the alignment control unit 44 drives the drive mechanism 15 to perform auto-alignment in the quick mode based on the detection result of the relative position of the subject's eye E after completion of the temporary alignment obtained in step S3 (step S7B, corresponding to the alignment step of the present invention). At this time, the alignment control unit 44 simplifies (speeds up) the auto-alignment by setting the allowable range of the alignment position of the measurement head 18 with respect to the subject's eye E wider than in the normal mode.

[0069] When the auto-alignment before the main measurement is completed, the measurement control unit 46 controls the pattern light projection optical system 28 and the measurement optical system 30 to perform the main measurement of the refractive power measurement without performing cloud vision on the subject's eye E (cloud vision skip) (step S8B, which corresponds to the eye characteristics acquisition step of the present invention). When the main measurement is completed, the eye characteristics calculation unit 48 calculates the main measurement value of the eye refractive power of the subject's eye E.

[0070] In this way, quick mode allows for easier (faster, but less accurate) measurement of the refractive power of the subject's eye E than normal mode by widening the auto-alignment tolerance, reducing the number of auto-alignment runs, skipping provisional measurements, and even skipping cloud vision in the actual measurement. Because subjects with nystagmus or restless children have difficulty staring at a fixation target for a certain period of time, normal mode refractive power measurement takes time. Furthermore, children tend to become less cooperative with the measurement the longer the measurement takes, which can lead to measurement failure. In contrast, quick mode refractive power measurement allows for the measurement to be completed in a shorter time by skipping some processes, although the accuracy of the measurement is reduced.

[0071] As described above, in this embodiment, a temporary alignment is performed before auto-alignment and refraction measurement, and the operating mode for auto-alignment and refraction measurement appropriate for the subject's eye E (subject) can be automatically selected based on the relative position of the subject's eye E before and after the temporary alignment. Therefore, in this embodiment, as described in Patent Document 1, the examiner does not need to manually switch operating modes or wait for quick mode measurement until measurement of the eye's refractive power in normal mode fails. As a result, refraction measurement can be performed quickly in quick mode for a subject's eye E that suffers from nystagmus or a restless child. This allows refraction measurement to be performed easily and quickly even when the subject's eye E suffers from nystagmus or the subject is a child.

[0072] [Second embodiment] 4 is a block diagram showing a schematic configuration of an ophthalmic apparatus 10 according to a second embodiment. In the ophthalmic apparatus 10 according to the first embodiment, the operation mode of auto-alignment and reflex measurement is selected based on the relative position of the subject's eye E before and after one temporary alignment. In contrast, in the ophthalmic apparatus 10 according to the second embodiment, instead of selecting the operation mode based on the relative position of the subject's eye E before and after one temporary alignment, temporary alignment is performed multiple times, and the operation mode is selected based on the relative position of the subject's eye E before and after each temporary alignment.

[0073] 4, the ophthalmic apparatus 10 of the second embodiment has basically the same configuration as the ophthalmic apparatus 10 of the first embodiment, except that the control device 20 functions as a repeat control unit 41. Therefore, components that are the same in function or configuration as those of the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0074] The temporary alignment control unit 36 ​​of the second embodiment is basically the same as the temporary alignment control unit 36 ​​of the first embodiment, but further has the function of performing temporary alignment based on the position detection result of the relative position detection unit 34 detected after the completion of the previous temporary alignment.

[0075] The repeat control unit 41 executes repeat control to repeatedly operate the temporary alignment control unit 36, the re-detection unit 38, and the determination unit 40 one or more times after the first determination by the determination unit 40. The upper limit number of times of this repeat control is determined in advance. As a result, temporary alignment, detection of the relative position of the subject's eye E, and determination by the determination unit 40 are executed multiple times.

[0076] The operation mode selection unit 42 of the second embodiment counts the number of times the determination unit 40 makes a negative determination. The operation mode selection unit 42 then performs a selection process to select the quick mode as the operation mode for auto-alignment and REF measurement when the count value of the number of determinations reaches a predetermined number, and to select the normal mode as the operation mode when the number of repeated controls reaches an upper limit without the count value reaching the predetermined number. This selection process corresponds to the second selection process of the present invention.

[0077] 5 is a flowchart showing the flow of the reflex measurement process of the subject's eye E by the ophthalmologic apparatus 10 of the second embodiment. As shown in Fig. 5, the processes from step S1 to step S5 described in the first embodiment (see Fig. 3) are executed, and if the determination unit 40 determines that the result is negative (NO in step S5), the operation mode selection unit 42 counts up the counter (increments the count value by 1) (step S5A).

[0078] Then, if the count value of the counter described above has not reached a predetermined number of times (NO in step S5B) or if the determination unit 40 determines that the measurement head 18 has approached the subject's eye E by a distance equal to or greater than the threshold (YES in step S5), the repeat control unit 41 starts repeat control (NO in step S5C). As a result, the temporary alignment control unit 36 ​​drives the drive mechanism 15 to perform temporary alignment based on the detection result of the relative position detection unit 34 in step S3 (step S2). When this temporary alignment is completed, the processes from step S4 to step S5B described above are repeatedly executed.

[0079] Hereafter, if the count value of the counter (the number of times the judgment unit 40 judges the result to be negative) does not reach the predetermined number of times in step S5B (NO in step S5B), and the number of times the repeat control by the repeat control unit 41 has not reached the upper limit number of times (NO in step S5C), the repeat control (steps S2 to S5B) is repeatedly executed.

[0080] If the count value of the counter reaches a predetermined number in step S5B (YES in step S5B), the operation mode selection unit 42 selects the quick mode as the operation mode for auto-alignment and reflex measurement (step S6B).Also, if the number of repeated controls reaches an upper limit in step S5C (YES in step S5C), the operation mode selection unit 42 selects the normal mode as the operation mode for auto-alignment and reflex measurement (step S6A).

[0081] The subsequent processing is the same as that of the first embodiment shown in FIG. 3, and therefore a detailed description thereof will be omitted here.

[0082] As described above, in the second embodiment, temporary alignment is performed multiple times, and the operating mode for auto-alignment and reflex measurement is selected based on the multiple judgment results by the judgment unit 40, so that an operating mode that is more suitable for the test eye E (subject) can be selected than in the first embodiment described above.

[0083] [Third embodiment] 6 is a block diagram showing a schematic configuration of an ophthalmic apparatus 10 according to a third embodiment. The ophthalmic apparatus 10 according to each of the above embodiments selects an operation mode for auto-alignment and reflex measurement based on the relative position of the subject's eye E before and after temporary alignment, and performs the auto-alignment and reflex measurement according to the selected operation mode. In contrast, the ophthalmic apparatus 10 according to the third embodiment performs auto-alignment and reflex measurement in an operation mode suited to the subject's eye E (subject) using a method different from that of each of the above embodiments.

[0084] 6, the ophthalmic apparatus 10 of the third embodiment has basically the same configuration as the ophthalmic apparatus 10 of each of the above embodiments, except that it includes a control device 50 different from that of each of the above embodiments. Therefore, components that are the same in function or configuration as those of each of the above embodiments are assigned the same reference numerals, and descriptions thereof will be omitted.

[0085] The control device 50 of the third embodiment executes a control program stored in a storage unit (not shown) to function as a relative position detection unit 52, a first determination unit 54, a second determination unit 56, an alignment control unit 58, a repetition control unit 60, a normal mode control unit 62, a quick mode control unit 64, and an eye characteristics calculation unit 66. In the third embodiment, the operation mode for auto-alignment and reflex measurement is set to the normal mode as an initial setting.

[0086] The relative position detection unit 52 is basically the same as the relative position detection unit 34 in each of the above-described embodiments, and constitutes the detection unit of the present invention together with the alignment optical system 26 and the observation optical system 24. When the examiner performs an operation to start reflex measurement, the relative position detection unit 52 executes the above-described relative position detection process to detect the relative position of the subject's eye E with respect to the measurement head 18.

[0087] The first determination unit 54 determines, based on the position detection result of the relative position detection unit 52, whether the current position of the measuring head 18 is within the allowable range (target value) of the alignment position of the measuring head 18 with respect to the subject's eye E after completion of auto-alignment.

[0088] The second determination unit 56 operates when the first determination unit 54 determines "No" and determines whether a transition flag for transitioning the operation mode for auto-alignment and reflex measurement from normal mode to quick mode has been established. For example, the second determination unit 56 counts the number of auto-alignments in normal mode executed by the alignment control unit 58 (described below), and determines whether the transition flag has been established based on whether the number of auto-alignments has reached a predetermined number.

[0089] If the second determination unit 56 determines that the result is negative (the transition flag is not established), the alignment control unit 58 drives the drive mechanism 15 based on the position detection result of the relative position detection unit 34 to perform auto-alignment in the normal mode.

[0090] The repetitive control unit 60 performs repetitive control to repeatedly operate the relative position detection unit 52, the first judgment unit 54, the second judgment unit 56, and the alignment control unit 58 until the first judgment unit 54 determines that the current position of the measuring head 18 is within the aforementioned allowable range, or until the second judgment unit 56 determines that the transition flag has been established.

[0091] The normal mode control unit 62 operates when the first determination unit 54 determines that the current position of the measurement head 18 is within the aforementioned allowable range. The normal mode control unit 62 controls each optical system of the measurement head 18 and the alignment control unit 58 to execute normal mode measurement processing. This normal mode measurement processing includes, for example, the temporary measurement in the normal mode described in each of the above embodiments, detection of the relative position of the subject's eye E, auto-alignment before the main measurement, and the main measurement.

[0092] The quick mode control unit 64 operates when the second determination unit 56 determines that the transition flag is set. The quick mode control unit 64 controls each optical system of the measurement head 18 and the alignment control unit 58 to execute quick mode measurement processing. This quick mode measurement processing includes, for example, the auto-alignment and main measurement (fog skip) in quick mode described in each of the above embodiments.

[0093] The eye characteristic calculation unit 66 is basically the same as the eye characteristic calculation unit 48 in each of the above embodiments, and in normal mode it calculates the provisional measurement value of the eye refractive power of the test eye E in the provisional measurement and the actual measurement value of the eye refractive power of the test eye E in the actual measurement, and in quick mode it calculates the actual measurement value of the eye refractive power of the test eye E in the actual measurement.

[0094] 7 is a flowchart showing the flow of a reflex measurement process of the subject's eye E by the ophthalmologic apparatus 10 of the third embodiment. As shown in FIG. 7, the operation mode for auto-alignment and reflex measurement is set in advance to the normal mode (step S21).

[0095] When the examiner performs the operation to start the reflex measurement, the relative position detection unit 34 controls the alignment optical system 26 and the observation optical system 24 to perform the above-mentioned relative position detection process, thereby detecting the relative position of the test eye E with respect to the measurement head 18 (step S22, which corresponds to the detection step of the present invention).

[0096] Next, the first determination unit 54 determines whether or not the current position of the measuring head 18 is within the above-mentioned allowable range based on the position detection result of the relative position detection unit 34 (step S23, corresponding to the first determination step of the present invention). Note that the initial determination by the first determination unit 54 is performed in a state where no auto-alignment has been performed. In this case, it is unlikely that the current position of the measuring head 18 is within the allowable range, and therefore the first determination unit 54 is likely to determine that the current position is not within the allowable range.

[0097] If the first determination unit 54 determines that the transition is not possible (NO in step S23), the second determination unit 56 determines whether the transition flag is set (step S24, which corresponds to the second determination step of the present invention). Note that the first determination by the second determination unit 56 is also performed in a state where no auto-alignment has been performed. Therefore, the number of auto-alignments has not reached the predetermined number, and the second determination unit 56 determines that the transition is not possible (NO in step S24).

[0098] If the second judgment unit 56 judges that the result is negative, the alignment control unit 58 drives the drive mechanism 15 based on the position detection result of the relative position detection unit 34 in step S22 to perform auto-alignment in normal mode (step S25, which corresponds to the alignment step of the present invention).

[0099] Thereafter, the repeat control unit 60 executes the repeat control described above (corresponding to the repeat control step of the present invention) until the first determination unit 54 determines that the current position of the measuring head 18 is within the aforementioned allowable range (YES in step S23) or the second determination unit 56 determines that the transition flag is set (YES in step S24). As a result, the processing from step S21 to step S25 is repeatedly executed one or more times.

[0100] If there are no problems such as nystagmus occurring in the subject's eye E or the subject being a restless child, the current position of the measuring head 18 is set within the above-mentioned allowable range by performing auto-alignment one or more times. In this case, the first determination unit 54 determines that the current position of the measuring head 18 is within the allowable range (YES in step S23), and the above-mentioned auto-alignment (repeated control) ends (step S26).

[0101] Next, the normal mode control unit 62 controls the optical systems of the measurement head 18, the alignment control unit 58, and the ocular characteristics calculation unit 66 to execute normal mode measurement processing (step S27, which corresponds to the normal mode control step of the present invention). This executes the processing from step S8A to step S11A of the first embodiment described above with reference to Fig. 3. By performing normal refractive measurements (provisional measurement and main measurement), the ocular refractive power of the subject's eye E can be measured with high accuracy.

[0102] On the other hand, if the subject's eye E has nystagmus or the subject is a restless child, the current position of the measuring head 18 will not be set within the aforementioned allowable range even if auto-alignment is repeated a predetermined number of times. In this case, the second determination unit 56 determines whether the transition flag is set (NO in step S23, YES in step S24). As a result, the operation mode for auto-alignment and reflex measurement is switched from the normal mode to the quick mode (step S28).

[0103] Next, the quick mode control unit 64 controls each optical system of the measurement head 18, the alignment control unit 58, and the eye characteristic calculation unit 66 to execute quick mode measurement processing (step S29, corresponding to the quick mode control step of the present invention). As a result, the processing from step S7B to step S8B of the first embodiment described in FIG. 3 above is executed. Thereby, even for the subject eye E in which nystagmus occurs or a fidgety child, etc., the refractive power of the subject eye E can be measured.

[0104] As described above, also in the third embodiment, by executing the automatic selection process of the operation mode from step S22 to step S25, automatic alignment and refraction measurement can be performed in an operation mode suitable for the subject eye E (subject). As a result, the same effects as those of the above embodiments can be obtained.

[0105] Note that the second determination unit 56 of the third embodiment determines the establishment of the transition flag based on whether or not the number of times of auto-alignment in the normal mode has reached a predetermined number of times. However, the method for determining the establishment of the transition flag is not particularly limited. For example, each time the relative position detection unit 52 detects the relative position of the subject eye E, the second determination unit 56 performs a process of calculating the distance from the measurement head 18 to the subject eye E (even within the allowable range described above, the absolute value of the XYZ coordinates or the root mean square of the XYZ coordinates), and a process of counting the number of times exceeding the threshold, which is the number of times this distance exceeds a predetermined threshold. Then, when arbitrary natural numbers are set as m and n (m < n), the second determination unit 56 determines the establishment of the transition flag based on whether or not the number of times exceeding the threshold has reached a predetermined number of times (m times) during n times of auto-alignment.

[0106] Alternatively, instead of the above determination method, each time the relative position of the subject eye E is detected by the relative position detection unit 52, the second determination unit 56 may calculate the RMS (Root Mean Square) indicating the variation of the relative position detection results for n times based on the relative position detection results (coordinates or the distance to the subject eye E) by the relative position detection unit 52 for an arbitrary plurality of times (n times: n is a natural number of 2 or more).

[0107] For example, the second determination unit 56 stores the first relative position detection result by the relative position detection unit 52 as R1, and the nth relative position detection result as Rn. The second determination unit 56 then calculates the RMS using the formula (RMS=√{(1 / n)×(ΣR1^2+R2^2+···)}). If the subject's eye E is experiencing nystagmus or if the subject is a restless child, the RMS calculation result will be large; if there is no particular problem, the RMS calculation result will be small. For this reason, the second determination unit 56 determines whether the transition flag is established based on whether the RMS calculation result is greater than a predetermined threshold. Note that although the RMS is calculated as the variation in the relative position detection results, there is no particular limitation as long as it is a statistical value indicating the variation.

[0108] [Fourth embodiment] The ophthalmic apparatus 10 of the third embodiment performs the normal mode measurement process by the normal mode control unit 62, which is the process from step S8A to step S11A of the first embodiment, i.e., temporary alignment, detection of the relative position of the subject's eye E, auto-alignment, and main measurement. In contrast, the ophthalmic apparatus 10 of the fourth embodiment performs the same process as the automatic selection process of the operating mode from step S22 to step S25 shown in Fig. 7 after the temporary measurement and before the main measurement. Note that the ophthalmic apparatus 10 of the fourth embodiment has the same configuration as the ophthalmic apparatus 10 of the third embodiment, and therefore, components that are the same in function or configuration as those of the above embodiments will be assigned the same reference numerals and their description will be omitted.

[0109] FIG. 8 is a flowchart showing the flow of normal mode measurement processing in the ophthalmologic apparatus 10 of the fourth embodiment.

[0110] As shown in FIG. 8, after the completion of the provisional measurement (step S8A), the relative position detection unit 34 detects the relative position of the subject eye E (step S30), and based on the position detection result, the first judgment unit 54 judges whether the current position of the measurement head 18 is within the aforementioned allowable range (step S31).

[0111] If the first determination unit 54 determines that the transition is not possible (NO in step S31), the second determination unit 56 determines whether the transition flag is set (step S32). If the second determination unit 56 determines that the transition is not possible (NO in step S32), the alignment control unit 58 drives the drive mechanism 15 based on the position detection result of the relative position detection unit 34 in step S30 to perform auto-alignment in the normal mode (step S33).

[0112] Thereafter, the repeat control unit 60 repeatedly executes the processing from step S30 to step S33 until the first judgment unit 54 judges that the current position of the measuring head 18 is within the aforementioned allowable range (YES in step S31) or the second judgment unit 56 judges that the transition flag is established (YES in step S32).

[0113] When the first determination unit 54 determines that the current position of the measurement head 18 is within the allowable range (YES in step S31), the auto-alignment (repeated control) ends (step S34). Then, the normal mode control unit 62 controls the optical systems of the measurement head 18 and the eye characteristics calculation unit 66 to perform the main measurement in the normal mode and calculate the main measurement value of the eye refractive power of the subject's eye E (step S35).

[0114] On the other hand, if the second determination unit 56 determines that the transition flag is set (YES in step S32), the operation mode of the auto-alignment and reflex measurement is switched from normal mode to quick mode (step S36). Then, the quick mode control unit 64 controls each optical system of the measurement head 18, the alignment control unit 58, and the ocular characteristic calculation unit 66 to perform auto-alignment in quick mode (step S37), and then performs the main measurement (skip fogging) (step S38).

[0115] As described above, in the fourth embodiment, by executing the automatic operation mode selection process from step S30 to step S33 between the provisional measurement and the main measurement in the normal mode REF measurement, the main measurement can be automatically performed in the operation mode suitable for the subject's eye E (subject). As a result, the same effects as those of the above embodiments can be obtained.

[0116] [others] In each of the above embodiments, the relative position detection units 34, 52 control the alignment optical system 26 and the observation optical system 24 to detect the relative position of the subject's eye E with respect to the measurement head 18, but the method for detecting this relative position is not particularly limited, and for example, a stereo camera may be used for detection. Furthermore, the relative position in the XY directions may be detected using the observation optical system 24, and the relative position in the Z direction may be detected using a separate sensor.

[0117] In the above embodiments, examples have been described in which the number of auto-alignments in quick mode is reduced compared to auto-alignment in normal mode and the tolerance range for the position of the measuring head 18 after alignment is completed is widened, but only one of these may be performed. Furthermore, as auto-alignment in quick mode, the driving of the drive mechanism 15 may be stopped after the position of the measuring head 18 with respect to the eye E to a certain extent, and in that state, the relative position detection units 34, 52 may repeatedly detect the relative position.

[0118] In the first and second embodiments, the operation mode selection unit 42 selects the quick mode as the operation mode for both auto-alignment and REF measurement when a predetermined condition (NO in step S5 or YES in step S5B) is satisfied, but the present invention is not limited to this. For example, when the above-mentioned predetermined condition is satisfied, the operation mode selection unit 42 may select the normal mode as the operation mode for one of auto-alignment and REF measurement, and the quick mode as the operation mode for the other.

[0119] Also, in the third and fourth embodiments, when the second judgment unit 56 determines that the transition flag is set, auto-alignment and REF measurement are performed in quick mode, but one of these may be performed in normal mode and the other in quick mode.

[0120] In the above-described embodiments, the ophthalmic apparatus 10 that measures the ocular refractive power of the subject's eye E has been described as an example, but the present invention can also be applied to an ophthalmic apparatus that acquires various ocular characteristics other than ocular refractive power (intraocular pressure, corneal endothelial cell count, fundus observation image, tomographic image, etc.). The present invention can also be applied to a multifunction device that acquires multiple types of ocular characteristics of the subject's eye E, and in this case, the method described in the above-described embodiments is executed each time different ocular characteristics are acquired, i.e., each time auto-alignment is performed. [Explanation of symbols]

[0121] 10...Ophthalmological equipment 12...Bass 13...Face support 13a...Chin rest 13b...Forehead protector 14... Mounting stand 15...Drive mechanism 16...Operating lever 17...Monitor 18...Measuring head 20...Control device 22…Fixation target projection optical system 24...Observation optical system 26...Alignment optical system 28...Pattern light projection optical system 30…Measurement optical system 32 steps 34...Relative position detection unit 36...Temporary alignment control unit 38...Redetection section 40…Judgment section 41...Repeat control section 42...Operation mode selection section 44...Alignment control unit 46...Measurement control section 48...Eye characteristic calculation section 50...Control device 52...Relative position detection unit 54...1st judgment section 56…Second judgment part 58...Alignment control unit 60...Repeat control section 62...Normal mode control section 64...Quick mode control section 66...Eye characteristic calculation section E: Eye to be examined

Claims

1. an eye characteristic acquisition unit that acquires eye characteristics of the subject's eye; a relative movement unit that moves the eye characteristic acquisition unit relative to the subject's eye; a detection unit that detects a relative position of the subject's eye with respect to the eye characteristic acquisition unit; a temporary alignment control unit that drives the relative movement unit based on a detection result of the detection unit to perform temporary alignment of the eye characteristic acquisition unit with respect to the subject's eye; a re-detection unit that causes the detection unit to repeatedly detect the relative position after the completion of the temporary alignment; a determination unit that determines whether the eye characteristic acquisition unit has come closer to the subject's eye by a distance equal to or greater than a predetermined threshold value due to the temporary alignment, based on detection results of the detection unit before and after the temporary alignment; an operation mode selection unit that selects, based on a determination result of the determination unit, either a normal mode or a quick mode that is simpler than the normal mode as an operation mode for aligning the eye characteristic acquisition unit with the subject's eye and acquiring the eye characteristics by the eye characteristic acquisition unit; an alignment control unit that drives the relative movement unit based on a detection result of the detection unit after completion of the temporary alignment, and performs the alignment in the operation mode selected by the operation mode selection unit; a measurement control unit that, after the alignment is completed, causes the eye characteristic acquisition unit to acquire the eye characteristic in the operation mode selected by the operation mode selection unit; and Equipped with The operation mode selection unit executes a first selection process to select the normal mode as the operation mode for both the alignment and the acquisition of eye characteristics when the judgment unit determines that the object has approached by a distance greater than or equal to the threshold value, and to select the quick mode as the operation mode for at least one of the two operations when the judgment unit determines that the object has approached by a distance greater than or equal to the threshold value.

2. the temporary alignment control unit is capable of executing the temporary alignment based on a detection result of the detection unit after completion of the temporary alignment, a repeat control unit that executes repeat control to repeatedly operate the temporary alignment control unit, the re-detection unit, and the determination unit one or more times after a first determination by the determination unit; 2. The ophthalmologic apparatus according to claim 1, wherein, when the repetitive control is executed, the operation mode selection unit executes a second selection process, instead of the first selection process, in which the operation mode selection unit selects the quick mode as the operation mode of at least one of the two devices when the number of judgments made by the judgment unit as negative reaches a predetermined number, and selects the normal mode as the operation mode of both devices when the number of judgments made by the judgment unit as negative reaches a predetermined upper limit number.

3. an eye characteristic acquisition unit that acquires eye characteristics of the subject's eye; a relative movement unit that moves the eye characteristic acquisition unit relative to the subject's eye; a detection unit that detects a relative position of the subject's eye with respect to the eye characteristic acquisition unit; a first determination unit that determines whether or not a position of the eye characteristic acquisition unit is within an allowable range of an alignment position of the eye characteristic acquisition unit with respect to the subject's eye, based on a detection result of the detection unit; a second determination unit that, when the first determination unit determines "no," determines whether or not a transition flag is established to transition at least one of the operation modes of alignment of the eye characteristic acquisition unit with the subject's eye by the relative movement unit and acquisition of the eye characteristic by the eye characteristic acquisition unit from a normal mode to a quick mode that is simpler than the normal mode; an alignment control unit that drives the relative movement unit based on the detection result of the detection unit when the second determination unit determines that the alignment is not performed, and performs the alignment in the normal mode; a repeat control unit that repeatedly operates the detection unit, the first determination unit, the second determination unit, and the alignment control unit until the first determination unit determines that the alignment is within the allowable range or until the second determination unit determines that the transition flag is set; a normal mode control unit that causes the eye characteristic acquisition unit to acquire the eye characteristic in the normal mode when the first determination unit determines that the eye characteristic is within the allowable range; a quick mode control unit that, when the second determination unit determines that the transition flag is set, causes the alignment control unit to perform the alignment and the eye characteristic acquisition unit to perform the eye characteristic acquisition in a state where at least one of them is in the quick mode; An ophthalmic device comprising:

4. The ophthalmic apparatus according to claim 3 , wherein the second determination unit counts the number of times the alignment is performed by the alignment control unit, and determines whether the transition flag is set or not based on whether the number of times the alignment has been performed reaches a predetermined number.

5. The ophthalmic device of claim 3, wherein the second determination unit performs a process of detecting the distance from the eye characteristic acquisition unit to the test eye each time the detection unit detects the relative position, and a process of counting the number of times the distance exceeds a predetermined threshold, and determines whether the transition flag is established or not based on whether the number of times the threshold is exceeded has reached a predetermined number.

6. 4. The ophthalmologic apparatus according to claim 3, wherein the second determination unit calculates a variance in the detection results of the relative position over multiple times each time the detection unit detects the relative position, and determines whether the transition flag is established based on whether the variance is greater than a predetermined threshold.

7. a detecting step of detecting a relative position of the subject's eye with respect to an eye characteristic acquiring unit that acquires eye characteristics of the subject's eye; a temporary alignment step of moving the eye characteristic acquisition unit relative to the subject's eye based on the detection result of the detection step, and performing temporary alignment of the eye characteristic acquisition unit with the subject's eye; a re-detection step of repeatedly executing the detection step after completion of the temporary alignment; a determining step of determining whether or not the eye characteristic acquiring unit has approached the subject's eye by a distance equal to or greater than a predetermined threshold value due to the temporary alignment, based on detection results of the detecting step before and after the temporary alignment; an operation mode selection step of selecting, based on a determination result of the determination step, either a normal mode or a quick mode that is simpler than the normal mode as an operation mode for aligning the eye characteristic acquisition unit with the subject's eye and acquiring the eye characteristics by the eye characteristic acquisition unit; an alignment step of moving the eye characteristic acquisition unit relative to the subject's eye based on a detection result of the detection step after completion of the temporary alignment, and performing the alignment in the operation mode selected in the operation mode selection step; an eye characteristic acquisition step of causing the eye characteristic acquisition unit to acquire the eye characteristics in the operation mode selected in the operation mode selection step after the alignment is completed; and The control method for an ophthalmic device, wherein the operation mode selection step executes a first selection process that selects the normal mode as the operation mode for both the alignment and the acquisition of eye characteristics if the judgment step determines that the subject has approached by a distance greater than or equal to the threshold, and selects the quick mode as the operation mode for at least one of the two if the judgment step determines that the subject has approached by a distance greater than or equal to the threshold.

8. a detecting step of detecting a relative position of the subject's eye with respect to an eye characteristic acquiring unit that acquires eye characteristics of the subject's eye; a first determination step of determining whether or not the relative position detected in the detection step is within an allowable range of an alignment position of the eye characteristic acquisition unit with respect to the subject's eye; a second determination step of determining whether or not a transition flag for transitioning at least one of the operation modes of alignment of the eye characteristic acquisition unit with respect to the subject's eye and acquisition of the eye characteristic by the eye characteristic acquisition unit from a normal mode to a quick mode that is simpler than the normal mode is established when the first determination step is determined to be negative; an alignment step of performing the alignment in the normal mode by moving the eye characteristic acquisition unit relative to the eye to be examined based on the detection result of the detection step when the second determination step determines "No"; a repeating step of repeatedly executing the detecting step, the first determining step, the second determining step, and the alignment step until the first determining step determines that the position is within the allowable range or the second determining step determines that the transition flag is set; a normal mode control step of causing the eye characteristic acquisition unit to acquire the eye characteristics in the normal mode when it is determined in the first determination step that the eye characteristics are within the allowable range; a quick mode control step of executing the alignment and the acquisition of the eye characteristics by the eye characteristic acquisition unit in a state where at least one of them is in the quick mode when it is determined in the second determination step that the transition flag is set to "established"; A method for controlling an ophthalmic apparatus having the above-mentioned features.

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