Optometer

Abstract

To enable correction of the positional deviation of a subject eye during an examination and perform the examination efficiently.SOLUTION: An optometer for subjectively measuring the optical characteristics of a subject eye, comprises: a measurement unit including a correction optical system for measuring the subjective optical characteristics of the subject eye; position detection means that detects the positional deviation of the subject eye during an examination relative to the correction optical system; information acquisition means that acquires objective eye refractive power information of the subject eye obtained before the subjective measurement; and control means that controls the operation of the optometer, and performs control related to correction of the positional deviation when the position detection means detects the positional deviation during the examination. Even if the positional deviation is detected by the position detection means during the examination, the control means suppresses the control related to the correction of the positional deviation on the basis of the eye refractive power information acquired by the information acquisition means.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic apparatus that automatically measures the optical characteristics of an eye to be examined.

Background Art

[0002] There is known an ophthalmic apparatus that measures optical characteristics such as the subjective refractive power (refractive error) of an eye to be examined by arranging a pair of left and right measurement units in front of the eye to be examined and showing a test target through a corrective optical system that is switchably arranged in an examination window of the measurement unit (see, for example, Patent Document 1). At the start of the examination, it is necessary to align the eye to be examined with a predetermined positional relationship with respect to the examination window (corrective optical system) of the measurement unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, even if the eye to be examined is aligned before the examination, the position of the eye to be examined may shift with respect to the examination window (corrective optical system) during the examination due to fatigue of the subject or the like. However, every time a positional shift occurs during the examination, correcting the positional shift has disadvantages such as interruption of the examination, poor examination efficiency, being troublesome, and imposing a burden on the subject.

[0005] The present disclosure provides an ophthalmic apparatus that can correct the positional shift of the eye to be examined during the examination and can perform the examination efficiently.

Means for Solving the Problems

[0006] The ophthalmic device of the present disclosure is an ophthalmic device for automatically measuring the optical characteristics of an eye to be examined, and includes a measurement unit including a correction optical system for measuring the subjective optical characteristics of the eye to be examined, position detection means for detecting a positional deviation of the eye to be examined during inspection with respect to the correction optical system, information acquisition means for acquiring objective eye refractive power information of the eye to be examined obtained before subjective measurement, and control means for controlling the operation of the ophthalmic device, the control means performing control related to correction of the positional deviation when the positional deviation is detected by the position detection means during inspection, and the control means suppressing control related to correction of the positional deviation based on the eye refractive power information acquired by the information acquisition means even when the positional deviation is detected by the position detection means during inspection.

Brief Description of Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0008] [Overview] Hereinafter, one typical embodiment will be described with reference to the drawings. Note that the items classified in the following <> can be used independently or in combination.

[0009] For example, a fundus camera (e.g., fundus camera 1) includes a measurement unit (e.g., measurement unit 100), a position detection means (e.g., imaging unit 160, front imaging unit 240, control unit 50), an information acquisition means (e.g., control unit 50), and a control means (e.g., control unit 50, control unit 150, control unit 250). For example, the fundus camera may include a notification means (e.g., control unit 50, monitor 310, voice generation unit 170) for notifying various information to the subject or examiner. For example, the fundus camera may include a target presentation unit (e.g., target presentation unit 200) for presenting an examination target.

[0010] <Measurement unit> For example, the measurement unit includes a corrective optical system (e.g., lens unit 130) for measuring the subjective optical characteristics of the eye to be examined. For example, the measurement unit switches and arranges the optical elements of the corrective optical system at the fundus window (e.g., fundus window 132). For example, the measurement unit includes a lens unit (e.g., lens unit 130) in which the corrective optical system is arranged, and a moving means (e.g., driving unit 141) for moving the lens unit at least in the left - right direction with respect to the subject's face.

[0011] <Position detection means> For example, the position detection means detects the positional deviation of the eye to be examined during the examination with respect to the corrective optical system. For example, the position detection means may include a side imaging unit (e.g., imaging unit 160) attached to the measurement unit and imaging the eye to be examined from the side. In this case, the side imaging unit may include an observation camera (e.g., observation camera 165L) for imaging the left eye to be examined from the left side and an observation camera (e.g., observation camera 165R) for imaging the right eye to be examined from the right side. Also, the position detection means may include a front imaging unit (e.g., front imaging unit 240) for imaging the eye to be examined from the front direction. For example, the position detection means detects the positional deviation of the eye to be examined based on the eye image captured by at least one of the side imaging unit or the front imaging unit.

[0012] <Information acquisition means> For example, the information acquisition means acquires objective eye refractive power information of the eye to be examined obtained before the autorefraction measurement. For example, the objective eye refractive power information includes the spherical power, astigmatism power, and astigmatism axis angle, which are the refractive errors of the eye to be examined.

[0013] <Control means> For example, the control means controls the operation of the ophthalmic apparatus. For example, when a position deviation of the eye to be examined is detected by the position detection means during the examination, the control means performs control regarding the correction of the position deviation detected by the position detection means during the examination. In this case, for example, the control means may perform control regarding the correction of the position deviation when the position deviation during the examination exceeds a predetermined allowable range.

[0014] For example, even when a position deviation is detected by the position detection means during the examination, the control means suppresses the control regarding the correction of the position deviation based on the eye refractive power information (for example, at least one of the astigmatism axis angle, astigmatism power, and spherical power) acquired by the information acquisition means. Thereby, the examination is not interrupted in the middle, the labor of correcting the position deviation is saved, and the examination can be performed efficiently. Also, the burden on the subject is reduced. Note that, for example, the suppression of the control regarding the correction of the position deviation may be to stop or prohibit the control regarding the correction of the position deviation. Note that, for example, the suppression of the control regarding the correction of the position deviation is not always performed by the position detection means for detecting the position deviation of the eye to be examined, but is performed at regular time intervals, so that the frequency of stopping or prohibiting the control regarding the correction of the position deviation can be suppressed. Also by this, the number of times the examination is interrupted in the middle is reduced, and the examination can be performed efficiently.

[0015] For example, when the eye refractive power information acquired by the information acquisition means includes the astigmatism axis angle, the control means may suppress the control regarding the correction of the position deviation of the eye to be examined in the direction of the astigmatism axis angle based on the astigmatism axis angle. Thereby, when a position deviation of the eye to be examined occurs in the direction of the astigmatism axis angle of the objective measurement, the examination can be performed efficiently without being interrupted in the middle.

[0016] For example, when the astigmatic axis angle of the heterophoric eye refractive power information is in the horizontal direction, even if a positional deviation in the left-right direction (X direction) is detected, the control regarding its correction may be suppressed. For example, when the astigmatic axis angle of the heterophoric eye refractive power information is in the vertical direction, even if a positional deviation in the up-down direction (Y direction) is detected, the control regarding its correction may be suppressed.

[0017] For example, when the astigmatism degree included in the heterophoric eye refractive power information is lower than a predetermined degree, the control regarding the correction of the positional deviation in the direction of the astigmatic axis angle may be suppressed. Thereby, when the astigmatism degree is lower than the predetermined degree, the inspection can be efficiently performed without being interrupted halfway.

[0018] For example, according to the astigmatism degree included in the heterophoric eye refractive power information, the predetermined allowable range of the positional deviation in the application of the function of suppressing the control regarding the correction of the positional deviation may be changed. By changing the allowable range of the positional deviation according to the astigmatism degree, even with the same amount of positional deviation, there may be a case where the control of the positional deviation correction is performed and a case where the control of the positional deviation correction is not performed. In the former case, an accurate inspection can be performed. In the latter case, the inspection is not interrupted, and the labor of correcting the positional deviation is omitted, and the inspection can be efficiently performed.

[0019] For example, according to the spherical degree included in the heterophoric eye refractive power information, the predetermined allowable range of the positional deviation in the application of the function of suppressing the control regarding the correction of the positional deviation may be changed. By changing the allowable range of the positional deviation according to the spherical degree, even with the same amount of positional deviation, there may be a case where the positional deviation correction is performed and a case where the control of the positional deviation correction is not performed. In the former case, an accurate inspection can be performed. In the latter case, the inspection is not interrupted, and the labor of correcting the positional deviation is omitted, and the inspection can be efficiently performed.

[0020] For example, the control means may control the driving of the moving means of the lens unit in order to correct the positional deviation in the left-right direction. In this case, even when a positional deviation is detected during the inspection, the control means may suppress the movement of the lens unit by the moving means according to the objective refraction power information. Thereby, it is possible to correct the positional deviation of the eye to be examined during the inspection as needed, and the inspection can be efficiently performed without performing unnecessary operations of the ophthalmic apparatus.

[0021] In addition, in the above, "during the inspection" means that after the alignment of the eye to be examined with respect to the ophthalmic window (correction optical system) of the measurement unit is completed for the first time, the eye to be examined is in a state of receiving the inspection. In other words, it means from the start to the end of the inspection after the alignment of the eye to be examined is completed.

[0022] [Embodiment] An embodiment of the present embodiment will be described with reference to the drawings. FIG. 1 is an external view of an ophthalmic apparatus 1 according to the present embodiment. The ophthalmic apparatus 1 includes a measurement unit 100, a target presentation unit 200, a controller 300 for ophthalmic examination, and the like. The measurement unit 100, the target presentation unit 200, and the controller 300 are connected to each other by wire or wirelessly.

[0023] In FIG. 1, a holding arm 280 is attached to the upper part of the housing 202 of the target presentation unit 200. The holding arm 280 holds the measurement unit 100 so as to be disposed at a predetermined position. For example, the holding arm 280 can hold the measurement unit 100 so as to be switched to at least one of a measurement position where it is lowered to the front of the housing 202 and a standby position where it is raised to the upper part of the housing 202. The holding arm 280 is driven by a drive unit 282 (see FIGS. 4 and 5). Note that the holding arm 280 may be configured as a multi-joint robot arm and may be configured to be three-dimensionally movable to an arbitrary position in the vertical, horizontal, and front-rear directions with respect to the housing 202 of the target presentation unit 200.

[0024] [Measurement Unit] FIG. 2 is a diagram for explaining the configuration of the measurement unit 100, and is a front view of the measurement unit 100 as viewed from the subject side. The measurement unit 100 includes a forehead rest 121, a lens unit 130, a moving unit 140, a photographing unit 160, and the like.

[0025] The forehead of the subject is brought into contact with the forehead rest 121. The forehead rest 121 is attached to the moving unit 140. The position of the forehead rest 121 in the front-rear direction (Z direction) is adjusted by the drive unit 122. When the forehead of the subject is brought into contact with the forehead rest 121 and the position of the forehead rest 121 in the front-rear direction (Z direction) is adjusted, the test eye (E) is positioned at a predetermined distance from the examination window 132 described later. A detector 123 is provided on the forehead rest 121. The detector 123 detects the contact between the head of the subject and the forehead rest 121. For example, the detector 123 may be an optical sensor, a pressure sensor, a load sensor, or the like.

[0026] The lens unit 130 includes a pair of left and right lens units, a left lens unit 130L and a right lens unit 130R. The lens unit 130 includes a lens disk 131 (a left lens disk 131L and a right lens disk 131R), which is an example of a correction optical system, an examination window 132 (a left examination window 132L and a right examination window 132R), and the like. The lens unit 130 also includes a through examination window (not shown) in the direction opposite to the subject side.

[0027] A plurality of optical elements 133 (a left optical element 133L and a right optical element 133R) are arranged on the same circumference of the lens disk 131. For example, the optical element 133 is a spherical lens, a cylindrical lens, a prism lens, or the like used as a correction optical system. For details of the lens disk 131 and the optical element 133, refer to, for example, Japanese Patent Application Laid-Open No. 2007-68574.

[0028] The lens disk 131 is rotated by the drive unit 134 (left drive unit 134L and right drive unit 134R). As a result, a desired optical element 133 is switched and arranged at the examination window 132. Further, some of the optical elements 133 (for example, a cylindrical lens, a prism lens, etc.) arranged at the examination window 132 are rotated by the drive unit 135 (left drive unit 135L and right drive unit 135R) about the center of the optical element 133.

[0029] The moving unit 140 is held by the holding arm 280. The moving unit 140 holds the left lens unit 130L and the right lens unit 130R so as to be movable in the left - right direction (X - direction). The left lens unit 130L is moved in the left - right direction (X - direction) by the left drive unit 141L of the drive unit 141. The right lens unit 130R is moved in the left - right direction (X - direction) by the right drive unit 141R of the drive unit 141. As a result, the left - right directions of the left and right examination windows 132 (left examination window 132L, right examination window 132R) are aligned with respect to the left and right eyes to be examined. That is, the interval between the left and right examination windows 132 is adjusted according to the inter - pupil distance PD of the left and right eyes to be examined.

[0030] Further, the moving unit 140 rotates the lens unit 130 in the convergence direction by the drive unit 142. For example, when the left lens unit 130L and the right lens unit 130R are both rotated in the convergence direction by the drive unit 142, the convergence angle (in - ward angle) in each lens unit is adjusted.

[0031] FIG. 3 is a schematic diagram for explaining the configuration of the photographing unit 160. In FIG. 3, the left photographing unit 160L provided in the left lens unit 130L is illustrated, and the right photographing unit 160R provided in the right lens unit 130R is omitted from illustration because it has a symmetrical configuration.

[0032] The left imaging unit 160L includes an observation window 162L and an observation camera 165L. The observation camera 165L images the left eye to be examined from the left side through the observation window 162L. Similarly, the right imaging unit 160R includes an observation window 162R (not shown) and an observation camera 165R (not shown). The observation camera 165R images the right eye to be examined from the right side through the observation window 162R. The lateral observation images of the eyes to be examined captured by the observation camera 165L and the observation camera 165R are displayed on the monitor 320 provided in the controller 300.

[0033] The examiner can confirm the alignment state in the front-rear direction (Z direction) with respect to the corrective optical system by observing the lateral observation images of the eyes to be examined displayed on the monitor 310. That is, the alignment state in the Z direction is confirmed by the distance VD (vertex distance VD) from the corneal apex position C of the eye to be examined to the lens (the back surface of the lens) of the corrective optical system arranged closest to the eye to be examined.

[0034] In addition, in order for the examiner to visually confirm the vertex distance VD between the corneas, a corneal position aiming optical system (an optical system provided with an aiming scale plate, a reticle plate, etc. on the observation window) may be additionally provided. For example, the corneal position aiming optical system can utilize the technology described in Japanese Patent Application Laid-Open No. 2018-89078.

[0035] <Visual target presentation unit> FIG. 4 is a diagram for explaining the configuration of the visual target presentation unit 200. The visual target presentation unit 200 includes a projection optical system 210 inside the housing 202. A presentation window 204 is provided on the front surface of the housing 202. An observation window 206 is provided on the back surface of the housing 202.

[0036] The presentation window 204 is a window for presenting a visual target to the eye to be examined. The presentation window 204 transmits the visual target light beam in the projection optical system 210 and projects the visual target light beam passing through the presentation window 204 onto the eye to be examined.

[0037] The observation window 206 is a window for confirming the positions of the pupil center of the eye to be examined and the retinoscopy window 132 of the measurement unit 100. The observation window 206 is disposed at a position where the pupil of the eye to be examined can be confirmed. Further, the observation window 206 is disposed outside the optical path through which the target light beam of the projection optical system 210 passes. For example, the examiner can grasp the positional relationship between the eye to be examined and the measurement unit 100 by looking through the observation window 206 and observing the positions of the eye to be examined and the retinoscopy window 132 (and the retinoscopy window on the side opposite to the subject side) through the presentation window 204 from outside the housing 202.

[0038] The projection optical system 210 includes a display 212, a half mirror 214, a concave mirror 316, an imaging element 165, etc. The display 212 displays a target (e.g., a fixation target, an examination target, etc.). The target light beam emitted from the display 212 travels along the optical axis L1, is reflected by the half mirror 214, and travels toward the concave mirror 316 along the optical axis L2. The target light beam reflected by the concave mirror 316 travels along the optical axis L3 and again heads toward the half mirror 214. The target light beam reflected by the half mirror 214 travels along the optical axis L4 and is guided to the eye to be examined through the presentation window 204 and the optical system of the measurement unit 100. That is, the eye to be examined observes the target presented in the direction of the optical axis L4.

[0039] For example, the focal length of the concave mirror 316 is designed such that the optical distance from the display 212 to the eye to be examined is 5 m. Thereby, the target presentation unit 200 is used as a space-saving type target presentation device capable of presenting a distance target. Further, the display 212 is moved by the drive unit 213, and since the display 212 is placed on the optical axis L3, a near target is presented to the eye to be examined. Note that instead of the concave mirror 316, an aspherical mirror, a free-form surface mirror, a lens, etc. may be used to guide the target light beam from the display 212 to the half mirror 214.

[0040] In addition, the visual target presentation unit 200 may additionally be provided with a front camera unit 240. The front camera unit 240 includes an observation camera 242. For example, the observation camera 242 is disposed in the transmission direction of the half mirror 214 (behind the half mirror 214) on the optical axis L4. The observation camera 242 images the eyes to be examined of both the left and right eyes from the front direction into the retinoscopy windows 132 of the measurement unit 100 (the left and right lens units 130) through the presentation window 204. For example, the front observation image of the eye to be examined captured by the observation camera 242 is displayed on the monitor 310. The examiner can confirm the alignment state of the eye to be examined in the left-right, up-down directions (XY directions) with respect to the corrective optical system by observing the front observation image of the eye to be examined displayed on the monitor 310.

[0041] <Controller> The controller 300 includes a monitor 310 and an operation unit 320. The monitor 310 displays information on various examination items of subjective refractive power, information on the visual targets presented by the visual target presentation unit 200, captured images of the eyes to be examined captured by the imaging unit 160 and the front camera unit 240, and the like. The operation unit 320 includes various switches for advancing the retinoscopy, switches for data input, switches for inputting signals for driving each drive unit (each drive unit included in the holding arm 280, the measurement unit 100, and the visual target presentation unit 200), and the like. Note that the monitor 310 may be a touch panel, or the monitor 310 may also serve as the function of the operation unit 320.

[0042] <Control system> FIG. 5 is a diagram showing the control system of the retinoscope 1. In FIG. 5, the control unit 150 included in the measurement unit 100 is connected to each drive unit of the measurement unit 100 and controls them. Further, an audio generation unit 170, which is an example of a sound generation means, is connected to the control unit 150. The control unit 250 included in the visual target presentation unit 200 is connected to the display 212, the drive unit 213, and the observation camera 242 and controls the driving thereof. Further, the control unit 250 is connected to the drive unit 282 included in the holding arm 280 and also controls the driving thereof.

[0043] The control unit 50 included in the controller 300 is connected to the monitor 310, the operation unit 320, and the storage unit 330. The control unit 50 controls the monitor 310 and receives the operation signals of the operation unit 320. Further, the control unit 50 is communicatively connected to the control unit 150 of the measurement unit 100 and the control unit 250 of the visual target presentation unit 200, either wired or wirelessly, and transmits command signals for driving each component to the control unit 150 and the control unit 250. That is, the control unit 50 controls the overall operation of the ophthalmic apparatus 1. Note that the control unit 50, the control unit 150, and the control unit 250 are composed of a general CPU, RAM, ROM, etc. For example, the ROM of the storage means of the control unit 50 stores a program for controlling the operation of the ophthalmic apparatus 1, an ophthalmic examination program for the examination procedure, etc.

[0044] In addition, the eye images of the subject obtained by the imaging unit 160 (the observation cameras 165L and 165R) are transmitted to the control unit 50 and displayed on the monitor 310. Also, the eye images of the subject obtained by the front imaging unit 240 (the observation camera 242) are transmitted to the control unit 50 and displayed on the monitor 310. Further, the control unit 50 constitutes position detection means for detecting the positional deviation of the subject's eye based on the eye image of the subject imaged by at least one of the imaging unit 160 or the front imaging unit 240.

[0045] In addition, the control unit 50 is connected to the heterophoria refractive power measuring device 70 of an external device via the data server 60 or directly. The heterophoric eye refractive power information (spherical power, astigmatism power, astigmatism axis angle), interpupillary distance information, etc. of the subject's eye obtained heterophorically by the heterophoria refractive power measuring device 70 are acquired by the control unit 50 which also serves as information acquisition means. Note that generally, the heterophoric eye refractive power information obtained by the heterophoria refractive power measuring device 70 is refractive error information with respect to emmetropia, and in this embodiment, it is handled as such. Note that, for example, the voice generation unit 170 and the monitor 310 are used as notification means for notifying various information to the subject or the examiner.

[0046] <Operation> In the ophthalmic apparatus 1 having the configuration as described above, its operation will be described. It is assumed that the refractive power information of the eye measured objectively by the objective ophthalmic refractive power measuring apparatus 70 has been obtained by the control unit 50 before the subjective measurement of the refractive power of the eye by the ophthalmic apparatus 1. For example, the objective refractive power information of the eye obtained by the objective ophthalmic refractive power measuring apparatus 70 is transferred as data to the control unit 50 via the data server 60 or directly. Note that the objective refractive power information may be manually input by the examiner operating the operation unit 320 of the controller 300.

[0047] <Ophthalmic examination preparation> At the start of the ophthalmic examination, the test eye is aligned with the left and right ophthalmic windows 132 (left ophthalmic window 132L and right ophthalmic window 132R) in a predetermined positional relationship.

[0048] For example, when the interpupillary distance PD (not shown) of the test eye measured by the objective ophthalmic refractive power measuring apparatus 70 is obtained together with the objective refractive power information of the eye, the information on the interpupillary distance PD is sent to the control unit 150 of the measurement unit 100. Then, based on the interpupillary distance PD, the control unit 150 controls the driving of the left driving unit 141L and the right driving unit 141R, and the left lens unit 130L and the right lens unit 130R are moved in the X direction, so that the X directions of the left ophthalmic window 132L and the right ophthalmic window 132R are aligned with the test eye. Note that when the interpupillary distance PD of the test eye has been obtained by an interpupillary distance meter, the examiner may operate the operation unit 320 of the controller 300 to input the value of the interpupillary distance PD.

[0049] Next, have the subject place their forehead against the forehead rest 121 and look through the ophthalmic window 132. At this time, an appropriate visual target (for example, a fixation target) may be presented by the visual target presentation unit 200 to guide the line of sight of the eye to be examined in the frontal direction. Then, the examiner observes the eye to be examined from the frontal direction through the observation window 206 and checks the alignment state of the eye to be examined in the XY directions (left-right direction and up-down direction). FIG. 6 is a view of the eye to be examined as seen through the observation window 206. The examiner checks the positional relationship between the center of the crosshair M of the lens located in the left and right ophthalmic windows 132 (here, the ophthalmic window located on the side opposite to the subject) and the pupil center PC of the eye to be examined. If the pupil center PC is displaced in the Y direction (up-down direction) with respect to the center of the crosshair M, have the subject move their face in the up-down direction to align the center of the crosshair M and the pupil center PC. Also, in the X direction, if the center of the crosshair M and the pupil center PC are displaced, the examiner operates the operation unit 320 of the controller 300 to input an operation signal for moving the left and right lens units 130 in the X direction. When this operation signal is received by the control unit 150 via the control unit 50, the left and right lens units 130 are moved in the X direction. Thereby, the alignment in the XY directions with respect to the inspection window 132 is completed.

[0050] Next, the examiner performs alignment of the eye to be examined in the Z direction. For the alignment of the eye to be examined in the Z direction, the captured images by the imaging unit 160 are used. The left and right images of the eye to be examined captured by the observation cameras 165L and 165R of the imaging unit 160 are displayed on the screen of the monitor 310.

[0051] FIG. 7 is a diagram showing an example of a screen when aligning the subject's eyes in the Z direction. In the screen 400 of FIG. 7, in the display section 402 at the lower right, the right eye side image ESR captured by the observation camera 165R and the left eye side image ESL captured by the observation camera 165L are displayed. The right eye side image ESR is displayed in the display section 402R, and the left eye side image ESL is displayed in the display section 402L. In the display sections 402R and 402L, the center line SC serving as the alignment reference and several scale lines S1 to S4 (the illustration of the display section 402L is omitted) are superimposed and displayed. For example, in the display section 402R, the center line SC corresponds to VD (distance between corneal vertices) = 13.75 mm, and the scale lines S1 to S4 correspond to VD = 12 mm, 16 mm, 18 mm, and 20 mm in order. The center line SC and the scale lines S1 to S4 in the display section 402L are horizontally reversed with respect to the display section 402R.

[0052] For example, the examiner observes the display sections 402R and 402L, and while the subject's forehead is in contact, moves the forehead rest 121 in the Z direction so that the corneal vertices of the left and right eyes to be examined are aligned with the center line SC. When the examiner operates the forehead rest forward and backward adjustment switch of the operation unit 320, the operation signal is sent from the control unit 50 to the control unit 150 of the measurement unit 100, and the drive unit 122 is driven under the control of the control unit 150, and the forehead rest 121 is moved in the Z direction. Thereby, the alignment of the eyes to be examined in the Z direction is performed. When an operation signal indicating the completion of alignment (for example, a completion switch signal displayed on the operation unit 320 or the monitor 310) is input, the side images ESR and ESL of the eyes to be examined (the images of the eyes to be examined in the alignment completed state) displayed on the display sections 402R and 402L are stored in the RAM (or the storage unit 330) of the storage means in the control unit 50.

[0053] In addition, when the visual target presentation unit 200 is provided with the observation camera 242 of the front imaging unit 240, in FIG. 7 showing an example of a screen during alignment, the right eye front image EFR and the left eye front image EFL captured by the observation camera 242 are displayed on the display section 404. The examiner may perform alignment in the XY direction by observing the right eye front image EFR and the left eye front image EFL.

[0054] <Self-examination>

[0055]

[0056]

[0057] Note that in the first red-green inspection step S4 to the second red-green inspection step S7, the inspection of the right eye is first performed, and then the inspection shifts to the left eye.

[0058] <Detection and Correction of Misalignment of the Eye Under Examination> In such an inspection step, during the inspection, the subject may move their face due to fatigue or the like. In this case, misalignment may occur with respect to the initial alignment state of the eye under examination with respect to the examination window (correction optical system). If the examiner proceeds with the inspection without noticing the misalignment of the eye under examination, the inspection results of the subjective inspection may become inaccurate. For this reason, in the ophthalmic apparatus 1 of the present embodiment, the alignment state of the eye under examination with respect to the correction optical system during the inspection is monitored, and misalignment of the eye under examination with respect to the correction optical system is detected. For example, for the detection of misalignment of the eye under examination, the observation cameras 165L and 165R of the imaging unit 160 are used.

[0059] FIG. 9 is a diagram for explaining the detection of misalignment of the eye under examination. FIG. 9(a) shows the right-eye image ESa of the eye under examination stored in the control unit 50 when the alignment of the eye under examination before the inspection is completed and imaged by the observation camera 165R. For example, the position of the eye under examination in the Z direction is aligned with the position on the center line SC in FIG. 7. The eye image ESa in FIG. 9(a) is shown as an image in which a part thereof is cut out in a predetermined region AE with respect to the right-eye side image ESR imaged by the observation camera 165R. The eye image ESa in the predetermined region AE at this time is used as the reference image EIS for alignment. Note that the position of the eye image ESa in the predetermined region AE is obtained by the control unit 50 performing image processing on the right-eye side image ESR. Then, by comparing the eye image ESa of the reference image EIS with the eye image ESa obtained at any time by the imaging unit 160 (observation camera 165R) during the inspection, the misalignment of the eye under examination in the XYZ directions during the inspection is detected by the control unit 50. Note that the process of cutting out the eye image in the predetermined region AE is not necessarily required, and the entire eye image imaged by the observation camera 165R may be subjected to image processing.

[0060] Fig. 9(b) shows an image ESa of the eye under examination acquired by the observation camera 165R when the eye under examination has a displacement in the Z direction during the examination. In this case, a change in the position in the Z direction of the corneal apex C of the eye image ESa during the examination is detected with respect to the eye image ESa of the reference image EIS, whereby the displacement amount ΔZ in the Z direction is detected.

[0061] Fig. 9(c) shows an image ESa of the eye under examination acquired by the observation camera 165R when the eye under examination has a displacement in the Y direction. In this case, a change in the position in the Y direction of the corneal apex C of the eye image ESa during the examination is detected with respect to the eye image ESa of the reference image EIS, whereby the displacement amount ΔY in the Y direction is detected. When the eye under examination has a displacement in the Y direction, the distance KD between the end point K1 where the cornea of the eye under examination intersects above the predetermined region AE and the end point K2 where the cornea of the eye under examination intersects below the predetermined region AE changes from the state in the reference image EIS. Therefore, the displacement amount ΔY in the Y direction may be detected thereby.

[0062] Fig. 9(d) shows an image ESa of the eye under examination acquired by the observation camera 165R when the eye under examination has a displacement in the X direction and the eye under examination has a displacement in the direction approaching the observation camera 165R. In this case, the corneal shape (corneal radius) Rb of the eye image ESa during the examination changes with respect to the corneal shape (corneal radius) Rs of the eye image ESa of the reference image EIS. In Fig. 9(d), since the eye under examination is moving in the direction approaching the observation camera 165R, the corneal shape (corneal radius) Rx during the examination changes greatly with respect to the corneal shape (corneal radius) Rs of the reference image EIS. Conversely, when the eye under examination is moving in the direction away from the observation camera 165R, the corneal shape (corneal radius) Rx during the examination changes to become smaller. Thereby, the displacement amount ΔX (not shown) in the X direction is detected.

[0063] Note that regarding the displacement of the left eye under examination, since it is detected by the same processing as above, the description thereof is omitted.

[0064] In addition, when the front imaging unit 240 is provided in the target presentation unit 200, the eye image acquired by the observation camera 242 may be used for detecting the positional deviation in the XY direction. For example, when the alignment with the eye to be examined is completed, the right eye front image EFR and the left eye front image EFL as shown in the display unit 404 of FIG. 7 are stored in the control unit 50 as reference images. During the examination, the eye image captured by the observation camera 242 is also acquired, and the positional deviation of the eye to be examined is detected based on the comparison between the eye image in the reference image and the eye image acquired during the examination. For example, based on the position change of the pupil center of the eye image acquired during the examination with respect to the pupil center of each of the left and right eyes in the reference image, the positional deviation amount ΔX in the X direction and the positional deviation amount ΔY in the Y direction may be detected.

[0065] In addition, since the positional deviation in the Z direction is likely to occur when the forehead rest 121 is displaced, when the detector 123 detects that the forehead of the subject has moved away from the forehead rest 121, it may be detected that the positional deviation in the Z direction has occurred.

[0066] <Correction of Positional Deviation of Eye to be Examined> In the detection of the positional deviation of the eye to be examined in the XYZ directions as described above, when the positional deviation is detected to exceed a predetermined allowable range TS respectively, the operation of the ophthalmic apparatus 1 is controlled by the control unit 50 (which may include the control unit 150 and the control unit 250) so that the positional deviation is corrected. For example, the fact that the positional deviation of the eye to be examined has occurred is notified to the examiner or the subject by at least one of display or voice. For example, the display on the monitor 310 is controlled, and on the screen during the examination on the monitor 310, a display indicating that the positional deviation of the subject has occurred and a display indicating the direction of the positional deviation are made. Alternatively, the voice generation unit 170 is controlled, and since the positional deviation has occurred, it is notified by voice guidance that it is necessary to move the eye to be examined in the direction to correct the positional deviation. Note that if the positional deviation is eliminated by correcting the positional deviation of the eye to be examined, the notification indicating that the positional deviation has occurred is cancelled.

[0067] When it is notified that there is a misalignment in the position of the eye to be examined, the examiner checks the positional relationship in the XYZ directions and corrects the misalignment in the position of the eye to be examined in the same manner as in the above-mentioned eye examination preparation. When the misalignment is notified by voice guidance, the subject himself / herself may correct the misalignment according to the voice guidance.

[0068] Also, regarding the correction of the misalignment in the X direction, the driving unit 141 is driven under the control of the control unit 50 (control unit 150), and the left and right lens units 130 are moved in the X direction based on the misalignment amount ΔX, and this may be performed. Also, regarding the correction of the misalignment in the Z direction, the forehead rest 121 may be moved in the Z direction based on the misalignment amount ΔZ. Since the subject positions his / her forehead on the forehead rest and often moves his / her face in the left-right direction, as the control for moving the measurement unit 100 (lens unit 130) for correcting the misalignment during the examination, it is sufficient that it can move at least in the X direction.

[0069] When such correction of the misalignment during the examination is performed, the examination is interrupted, the trouble of correcting the misalignment occurs, and the examination efficiency deteriorates. Also, a burden is imposed on the subject. Therefore, in the present disclosure, for misalignments that do not affect the eye examination result of the autorefractor eye examination, the control regarding the correction of the misalignment is suppressed. For example, the control regarding the correction of the misalignment is stopped or prohibited. For example, the stop or prohibition control regarding the correction of the misalignment is performed based on the objective eye refractive power information acquired in advance before the examination of the subjective measurement.

[0070] For example, when the objective measurement eye refractive power information includes the astigmatism axis angle of the astigmatism refractive error, the control regarding the correction of the misalignment of the eye to be examined in the direction of the astigmatism axis angle is stopped or prohibited. This is because even if there is a misalignment in the position of the eye to be examined in the direction of the astigmatism axis angle, there is no change (or little influence) in the astigmatism power of the astigmatism lens in the direction of the astigmatism axis angle.

[0071] Note that the above function (the function in which the control related to the correction of the position deviation based on the astigmatic axis angle is stopped or prohibited) may be applied to the astigmatism inspection steps (astigmatic axis inspection step S5 and astigmatic power inspection step S6) in FIG. 8 for each inspection of the right and left eyes. These inspections are for the purpose of minimizing the influence of spherical power on the position deviation. Further, the above function may be applied in the first red - green inspection step S4 and the second red - green inspection step S7. In these inspections, since a fog is applied to the eye to be examined, the influence of spherical power on the position deviation is small.

[0072] For example, when the astigmatic axis angle in heterophoria measurement is in the horizontal direction (which may include a predetermined allowable range), even if a position deviation in the X - direction is detected, the control related to its correction is stopped. That is, the notification to the subject and the examiner regarding the position deviation in the X - direction is stopped. Alternatively, the control for moving the left and right lens units 130 in the X - direction is prohibited.

[0073] Also, for example, when the astigmatic axis angle in heterophoria measurement is in the vertical direction (which may include a predetermined allowable range), even if a position deviation in the Y - direction is detected, the control related to its correction is stopped. That is, the notification to the subject and the examiner regarding the position deviation in the Y - direction is stopped.

[0074] In this way, even if a position deviation of the eye to be examined occurs in the direction of the astigmatic axis angle, since no notification or the like for correcting the position deviation is performed, the inspection can be efficiently carried out without being interrupted in the middle. Also, since no extra time is spent on correcting the position deviation, the burden on the subject is reduced.

[0075] Also, the stop or prohibition of the control for correcting the position deviation in the direction of the astigmatic axis angle is not limited to the horizontal and vertical directions. For example, when the astigmatic axis angle is 45 degrees (which may include a predetermined allowable range), if a combined position deviation in the X - direction and the Y - direction is detected in the 45 - degree direction, the control related to its correction may be stopped.

[0076] In addition, predetermined allowable ranges regarding the horizontal direction, vertical direction, etc. of the astigmatic axis angle are set to, for example, ±5 degrees respectively.

[0077] Also, whether control regarding correction of positional deviation is applied may be changed according to the astigmatic degree of heterometric measurement. For example, when the astigmatic degree is lower than a predetermined degree (for example, 3.0 D (diopter) or less), even if there is a positional deviation of the eye to be examined, the influence on the examination result is small. Therefore, when a positional deviation is detected in the direction of the astigmatic axis angle, the control regarding correction of the positional deviation may be stopped or prohibited. When the astigmatic degree is higher than a predetermined degree (for example, a degree exceeding 3.0 D), a function of stopping or prohibiting the control regarding correction of the positional deviation may not be applied (that is, even for the positional deviation in the direction of the astigmatic axis angle, the control regarding correction of the positional deviation is performed). In this case, the reliability of the examination result can be improved.

[0078] Also, the allowable range TS of the positional deviation for determining whether to perform control regarding correction of the positional deviation may be changed according to the astigmatic degree of heterometric measurement. For example, when the astigmatic degree of heterometric measurement exceeds 3.0 D, compared with the case where the astigmatic degree is 3.0 D or less, the allowable range TS of the positional deviation is set wider. Thereby, when the astigmatic degree exceeds 3.0 D, a more accurate examination can be performed by correcting the positional deviation. When the astigmatic degree is 3.0 D or less, the examination is not interrupted, and the trouble of correcting the positional deviation is omitted, and the examination can be performed efficiently.

[0079] Note that in the above, the application of the function of stopping or prohibiting the control regarding correction of the positional deviation has been described by examples based on the astigmatic axis angle and the astigmatic degree, but this may be applied according to the spherical degree of heterometric measurement.

[0080] For example, similar to the case of astigmatism, the tolerance range TS of misalignment for determining whether to perform control related to correction of misalignment may be changed according to the spherical power of heterometric measurement. For example, when the spherical power exceeds 3.0D, the tolerance range TS of misalignment is set wider than in the case of a low spherical power of 3.0D or less. Alternatively, the change in the tolerance range TS according to the spherical power of heterometric measurement may be not in two steps but in three or more steps. For example, for a weak spherical power (a power of 3.0D or less) of heterometric measurement, for a medium spherical power (a power exceeding 3.0D and not exceeding 6.0D), and for a strong spherical power (a power exceeding 6.0D) of heterometric measurement, the tolerance range TS is set stepwise narrower. Also by this, by stopping or prohibiting the control related to correction of misalignment according to the spherical power of heterometric measurement, the inspection is not interrupted, and the labor of correcting the misalignment is omitted, and the inspection can be performed efficiently.

[0081] <Modified Example> As described above, typical embodiments of the present disclosure have been described, but the present disclosure is not limited to the embodiments shown above, and various modifications are possible.

[0082] For example, in the above, it is assumed that the examiner accompanies the subject and operates the controller 300 to proceed with the inspection (ophthalmic examination), but it is not limited to this. For example, similar to Japanese Patent Application Laid-Open No. 2021-137293, the examiner may operate the controller 300 to perform the inspection at a location separated from the installation location of the measurement unit 100. Further, it may be a self-ophthalmic examination in which the subject himself / herself proceeds with the inspection without the intervention of the examiner. In these cases, instructions for alignment with the subject and instructions for proceeding with the inspection are issued from the voice generation unit 170.

[0083] Also, regarding detection of misalignment in the XY direction of the eye to be examined, in the above, an example of using the observation camera 242 of the front imaging unit 240 mounted on the target presentation unit 200 has been described, but it is not limited to this. For example, the front imaging unit 240 may be provided in the measurement unit 100. In this case, the observation cameras 242 of the front imaging unit 240 are respectively provided in the left lens unit 130L and the right lens unit 130R, and misalignments of the left and right eyes to be examined are respectively detected.

[0084] Also, the function of stopping or prohibiting the control related to the correction of the misalignment of the eye to be examined may be that the detection of the misalignment is stopped. For example, when the astigmatic axis angle of the heterophoria measurement is in the vertical direction, the detection of the misalignment in the X direction is stopped. Further, when the control related to the correction of the misalignment of the eye to be examined is stopped or prohibited, it may be notified that the correction of the misalignment is not necessary.

[0085] Also, in the control related to the correction of the misalignment of the eye to be examined, although the example in which the left and right lens units 130 are moved in the X direction has been described above, a mechanism in which the left and right lens units 130 are also moved in the Y and Z directions is provided in the moving unit 140, and the lens unit 130 is moved in the XYZ directions, so that the misalignment of the eye to be examined may be corrected.

[0086] Also, the detection of the misalignment of the eye to be examined by the position detection means (such as the observation camera 165) is not always performed, but is performed at regular time intervals (for example, every 10 seconds), so that the frequency of stopping or prohibiting the control related to the correction of the misalignment may be suppressed. By suppressing the control related to the correction of this misalignment, the number of times the inspection is interrupted in the middle is reduced, and the inspection can be performed efficiently.

Explanation of Signs

[0087] 1 Ophthalmic apparatus 50 Control unit 100 Measurement unit 130 Lens unit 132 Ophthalmic window 141 Driving unit 150 Control unit 160 Photographing unit 170 Voice generation unit 200 Visual target presentation unit 300 Controller 310 Monitor

Claims

1. An ophthalmic apparatus for automatically measuring the optical characteristics of an eye to be examined, comprising: a measurement unit including a correction optical system for measuring the subjective optical characteristics of the eye to be examined; position detection means for detecting a positional deviation of the eye to be examined during inspection with respect to the correction optical system; information acquisition means for acquiring objective eye refractive power information of the eye to be examined obtained before subjective measurement; control means for controlling the operation of the ophthalmic apparatus, the control means performing control regarding correction of the positional deviation when the positional deviation is detected by the position detection means during inspection; The control means suppresses control regarding correction of the positional deviation based on the eye refractive power information acquired by the information acquisition means even when the positional deviation is detected by the position detection means during inspection. The ophthalmic apparatus is characterized by this.

2. In the ophthalmic apparatus according to Claim 1, the control means suppresses control regarding correction of the positional deviation of the eye to be examined in the direction of the astigmatic axis angle based on the astigmatic axis angle included in the eye refractive power information. The ophthalmic apparatus is characterized by this.

3. In the ophthalmic apparatus according to Claim 2, the control means suppresses control regarding correction of the positional deviation in the direction of the astigmatic axis angle when the astigmatic degree included in the eye refractive power information is lower than a predetermined degree. The ophthalmic apparatus is characterized by this.

4. In the ophthalmic apparatus according to any one of Claims 1 to 3, the control means is means for performing control regarding correction of the positional deviation when the positional deviation exceeds a predetermined allowable range during inspection, and the allowable range is changed according to the astigmatic degree included in the eye refractive power information. The ophthalmic apparatus is characterized by this.

5. In the ophthalmic apparatus according to any one of Claims 1 to 3, the control means is means for performing control regarding correction of the positional deviation when the positional deviation exceeds a predetermined allowable range during inspection, and the allowable range is changed according to the spherical degree included in the eye refractive power information. The ophthalmic apparatus is characterized by this.

6. In the ophthalmic apparatus according to any one of Claims 1 to 5, notification means for notifying various information to the subject or the examiner is provided, the control means is means for controlling the notification means to notify the subject or the examiner that the positional deviation has occurred so that the subject can correct the positional deviation by moving the face, and suppresses notification by the notification means that the positional deviation has occurred based on the eye refractive power information. The ophthalmic apparatus is characterized by this.

7. In the ophthalmic apparatus according to any one of claims 1 to 6, the measurement unit includes a lens unit in which a correction optical system is arranged, and a moving means for moving the lens unit at least in the left-right direction with respect to the face of the subject. The control means is means for controlling the drive of the moving means to correct the positional deviation in the left-right direction, and suppresses the movement of the lens unit by the moving means according to the eye refractive power information even when the positional deviation is detected during the examination. An ophthalmic apparatus characterized by this.

8. In the ophthalmic apparatus according to any one of claims 1 to 7, The ophthalmic apparatus is characterized in that suppression of control related to correction of the positional deviation is to stop or prohibit control related to correction of the positional deviation.

Images