Eye examination device

Abstract

To properly determine the alignment state.SOLUTION: An optometer comprises: alignment detection means which detects the alignment state of inspection means to a subject eye; and control means which controls the operation of the optometer. The alignment detection means comprises: first index projection means which projects a first index for aligning the inspection means in a first direction being at least one direction of left-right, up-down and front-rear directions with respect to the subject eye onto the subject eye; a first detector which detects the first index projected onto the subject eye; second index projection means which projects a second index for aligning the inspection means in a second direction being at least one direction of the left-right, up-down and front-rear directions with respect to the subject eye and different from the first direction onto the subject eye; and a second detector which detects a second index projected onto the subject eye. The control means controls each exposure time of the first detector and the second detector in a shorter time than a frame interval such that timing of the exposure times does not overlap with each other.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an optometry apparatus for examining an eye to be examined. [Background Art]

[0002] Examination of optical characteristics and the like of an eye to be examined is performed after aligning an examination means in a predetermined positional relationship with respect to the eye to be examined. As a means for detecting the alignment state of the examination means with respect to the eye to be examined, for example, there has been proposed an apparatus provided with an alignment detection means of a type in which an index for detecting the horizontal and vertical alignment state with respect to the eye to be examined is projected onto the eye to be examined, an index for detecting the alignment state in the anterior-posterior direction (working distance direction) with respect to the eye to be examined is projected onto the eye to be examined, and the respectively projected indices are detected by separate detectors (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-38942 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in the alignment detection means of Patent Document 1, for example, not only the index for detecting the horizontal and vertical alignment state but also the index for detecting the alignment state in the anterior-posterior direction enters the detector for detecting the horizontal and vertical alignment state, so that there have been cases where the alignment state cannot be appropriately determined.

[0005] In view of the above prior art, an object of the present disclosure is to provide an optometry apparatus that can appropriately determine an alignment state. Another object of the present disclosure is to provide an optometry apparatus that can determine completion of alignment with appropriate timing without delaying the timing determination for examination execution. [Means for Solving the Problem]

[0006] An optometry apparatus according to an aspect of the present disclosure is an optometry apparatus comprising an examination means for examining an eye to be examined, the optometry apparatus comprising: an alignment detection means for detecting the alignment state of the examination means with respect to the eye to be examined, and a control means for controlling the operation of the optometry apparatus, wherein the alignment detection means comprises: a first indicator projection means for projecting a first indicator onto the eye to be examined for aligning the examination means in at least one of the left-right, up-down, and front-back directions; a first detector for detecting the first indicator projected onto the eye to be examined; a second indicator projection means for projecting a second indicator onto the eye to be examined for aligning the examination means in at least one of the left-right, up-down, and front-back directions, which is different from the first direction; and a second detector for detecting the second indicator projected onto the eye to be examined, wherein the control means controls the exposure time of the first detector and the second detector. Each The system is characterized by controlling the exposure time to be shorter than the frame interval, and ensuring that the timing of each exposure does not overlap. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows the schematic configuration of the external appearance of the eye examination device. [Figure 2] This is a diagram showing the optical system arranged in the measurement section. [Figure 3] This is a schematic diagram showing the internal structure of an eye examination device viewed from the front. [Figure 4] This is a schematic diagram showing the internal structure of an eye examination device viewed from the side. [Figure 5] This is a schematic diagram showing the internal structure of an eye examination device viewed from above. [Figure 6] This diagram shows the control system for an eye examination device. [Figure 7] This diagram illustrates an example of controlling the timing of exposure time for each image sensor and the timing of turning on each light source. [Figure 8] This figure shows an example of an image captured by an image sensor that detects alignment indices in the X and Y directions. [Figure 9]This figure shows an example of an image captured by an image sensor that detects the alignment index in the Z direction. [Modes for carrying out the invention]

[0008] [overview] A typical embodiment will be described below with reference to the drawings. The items classified in <> below can be used independently or in relation to each other.

[0009] The optometry device in this embodiment (for example, optometry device 1) comprises an inspection means (for example, a measuring unit 7), an alignment detection means (for example, an alignment detection optical system 50A), and a control means (for example, a control unit 70). For example, the inspection means is used to examine the eye under examination. For example, the alignment detection means is used to detect the alignment state of the inspection means with respect to the eye under examination. For example, the control means controls the operation of the optometry device. For example, the optometry device may also include a light guide optical system (for example, a light guide optical system 80).

[0010] <Inspection methods> For example, the testing means includes a testing optical system (e.g., an objective measurement optical system 10). For example, the testing optical system includes a testing light source (e.g., a light source 11) that projects testing light onto the eye under test, and a testing light receiving element (e.g., an image sensor 22) that receives the reflected light from the eye under test. For example, the testing means may include an objective measurement optical system (e.g., an objective measurement optical system 10) that measures the refractive power of the eye under test as the testing optical system. The testing means may also include a subjective measurement optical system (e.g., a subjective measurement optical system 25). For example, the subjective measurement optical system may include a target projection optical system (e.g., a target projection optical system 30) and a corrective optical system (e.g., a corrective optical system 60).

[0011] <Alignment detection means> For example, the alignment detection means includes a first index projection means (e.g., a first index projection optical system 55), a first detector (e.g., an image sensor 52), a second index projection means (e.g., a second index projection optical system 40a), and a second detector (e.g., an image sensor 48).

[0012] For example, the first indicator projection means projects a first indicator (e.g., indicator 56I) onto the eye under examination for aligning the examination means in at least one of the following directions: left-right (X direction), up-down (Y direction), and front-back (Z direction). For example, the first direction is left-right (X direction) or up-down (Y direction) relative to the eye under examination. For example, the first indicator projection means has a light source (e.g., light source 56) for projecting the indicator.

[0013] For example, the first detector detects a first indicator projected onto the eye under examination. For example, the first detector is provided in a first detection optical system (e.g., observation optical system 50) for detecting the first indicator projected onto the eye under examination. For example, the first detector may be at least one of a two-dimensional photodetector image sensor which is an area sensor, or a one-dimensional photodetector which is a line sensor. For example, the alignment state of the inspection means in a first direction is detected based on the output signal from the first detector.

[0014] For example, the second indicator projection means projects a second indicator (e.g., indicator 41I) for aligning the examination means in a second direction, which is different from the first direction, and is one of the left-right, up-down, or front-back directions relative to the eye under examination. For example, the second indicator may be a different indicator from the first indicator. For example, the second direction may be front-back (Z direction, working distance direction) relative to the eye under examination. For example, the second indicator projection means has a light source (e.g., light source 41) for projecting the indicator. For example, the wavelength of the light source for the second indicator may overlap with the wavelength of the light source for the first indicator in at least part.

[0015] For example, the second detector detects the second index projected onto the eye to be examined. For example, the second detector is provided in a second detection optical system (e.g., the second index projection optical system 40a) for detecting the second index projected onto the eye to be examined. For example, at least one of a two-dimensional light-receiving element imaging device that is an area sensor and a one-dimensional light-receiving element that is a line sensor is used as the second detector. For example, the alignment state of the inspection means in the second direction is detected based on an output signal from the second detector.

[0016] <Control means> For example, the control means controls the first detector and the second detector. For example, the control means performs control such that the timing of the exposure time of the first detector (e.g., exposure time Eta) and the exposure time of the second detector (e.g., exposure time Etb) do not overlap. For example, the control means controls the start and end timings of each exposure of the first detector and the second detector such that the exposure time of the first detector and the exposure time of the second detector do not overlap in terms of timing. This allows the alignment state to be appropriately determined.

[0017] For example, the control means controls each exposure time of the first detector and the second detector to be shorter than the frame interval of a predetermined frame rate (e.g., 30 fps (the number of frames per second)). This allows the alignment state to be appropriately determined. For example, both the detection of the first index by the first detector and the detection of the second index by the second detector are performed at a predetermined frame rate (e.g., 30 fps). Therefore, for example, although the detection of the alignment state in the left-right, up-down, and front-back directions uses the first detector and the second detector, detection results of the first index and the second index can be obtained within the same frame rate as that in the case of alignment detection performed by a single detector. This allows the completion of alignment to be determined in a timely manner, and enables inspection to be performed in a timely manner without causing a delay in the timing determination of inspection by the inspection means. Furthermore, this allows highly reliable inspection results to be obtained without reducing the accuracy of the inspection results.

[0018] Furthermore, the exposure time is defined as the period during which the detector captures light. Also, the frame interval is defined as the duration of one frame at a predetermined frame rate of the detector.

[0019] For example, the control means controls the exposure time of the first detector to be half the frame interval, and controls the exposure time of the second detector to be half the frame interval. The exposure times of the first detector and the second detector are not limited thereto. For example, it is only required that the total of the exposure time of the first detector and the exposure time of the second detector within one frame interval falls within the duration of the frame interval. For example, the exposure time of the first detector may be two-thirds of the frame interval, and the exposure time of the second detector may be one-third of the frame interval.

[0020] Furthermore, for example, the control means may adjust the frame phase relationship between the respective exposure times of the first detector and the second detector. For example, the control means may shift the relationship of the frame phase of the second detector relative to the frame phase of the first detector by the exposure time of the second detector. This enables more appropriate determination of the alignment state. In addition, shifting the frame phase prevents the frame signals from the first detector and the second detector from being output simultaneously, and instead allows them to be output sequentially, whereby processing for image analysis of each frame signal can be performed efficiently.

[0021] For example, the control means controls the first indicator projection means and the second indicator projection means. For example, the control means controls the first indicator projection means and the second indicator projection means so that the second indicator is not projected onto the eye under examination during the exposure time of the first detector, and the first indicator is not projected onto the eye under examination during the exposure time of the second detector. In this case, for example, the control means controls the illumination of the light source of the first indicator projection means and the light source of the second indicator projection means in accordance with the timing of the exposure times of the first detector and the second detector. Alternatively, mechanical or electronic shutters may be provided in the optical paths of the indicator projection of the first indicator projection means and the second indicator projection means, and the control means may control the opening and closing of the shutters provided in each optical path in accordance with the exposure times of the first detector and the second detector. This allows for a more appropriate determination of the misaligned alignment state in the left-right (X direction), up-down (Y direction), and front-back (Z direction) directions.

[0022] <Inspection optics and wavelength limiting means for alignment detection> For example, the inspection optical system may include a first wavelength limiting means (e.g., a dichroic mirror 29), and the alignment detection means may include a second wavelength limiting means (e.g., a dichroic mirror 29 and a lens 46). For example, the first wavelength limiting means is used to limit the wavelength of the reflected light from the eye under examination of the first and second indicators used for alignment to incident on the inspection light receiving element of the inspection optical system. For example, the second wavelength limiting means is used to limit the wavelength of the reflected light from the eye under examination of the inspection light to incident on the first and second detectors. This ensures that the inspection means can properly inspect the optical properties of the eye under examination without being affected by the first and second indicators projected onto the eye under examination, and that the alignment state based on the first and second indicators projected onto the eye under examination can be properly detected without being affected by the inspection light.

[0023] For example, the first wavelength limiting means includes a first optical element with wavelength-selective properties (e.g., a dichroic mirror 29) arranged in the optical path of the inspection optical system. For example, the first optical element with wavelength-selective properties allows the wavelength of the inspection light to pass through, but blocks the wavelengths of the first and second indicators, thereby limiting the incidence of the wavelengths of the first and second indicators into the optical path where the inspection photodetector is located.

[0024] For example, the second wavelength limiting means includes a second optical element (e.g., a dichroic mirror 29) with wavelength-selective properties, positioned in the optical path of the first detection optical system equipped with the first detector. For example, the second optical element allows the wavelength of the first indicator to pass through but blocks the wavelength of the inspection light, thereby limiting the incidence of the inspection light into the optical path where the first detector is located. The second wavelength limiting means also includes a third optical element (e.g., a lens 46) with wavelength-selective properties, positioned in the optical path of the second detection optical system equipped with the second detector. For example, the third optical element allows the wavelength of the second indicator to pass through but blocks the wavelength of the inspection light, thereby limiting the incidence of the inspection light into the optical path where the second detector is located.

[0025] For example, in a configuration where at least a portion of the wavelengths of the first indicator and the second indicator overlap, the first detector is incident on both the light of the first indicator and the light of the second indicator, and the second detector is incident on both the light of the second indicator and the light of the first indicator. Even in this case, the alignment state can be appropriately determined by controlling the timing of the exposure times of the first and second detectors by the control means.

[0026] <Light guide optical system> For example, the light guide optical system guides the indicator light of the first and second indicators to the eye under examination, and guides the reflected light of the indicator light from the eye under examination to the first and second detectors. The light guide optical system also guides the measurement light from the measurement optical system to the eye under examination, and guides the reflected light of the measurement light from the eye under examination to the measurement optical system. For example, the light guide optical system includes a light guide optical member (e.g., a concave mirror 85) to make it equivalent to the optical system of the examination means being optically positioned at a predetermined working distance in front of the subject's eyes when alignment is completed. For example, with this light guide optical system, the optometry device is configured so that alignment and measurement can be performed with the subject's eyes open, without having to position the examination means in front of the subject's eyes. This allows for measurement of the subject's eyes in a more natural state.

[0027] In this disclosure, by employing this light guide optical system, the indicator projection means used for aligning the inspection means with respect to the eye under examination can only project an indicator from an angle from which the indicator light beam can pass through the light guide optical member (e.g., concave mirror 85) of the light guide optical system. In this case, in order to detect the anterior-posterior alignment state of the inspection means with respect to the eye under examination with practical resolution, a detector (e.g., a first detector) for detecting the left-right and up-down alignment states cannot be used. Therefore, in addition to the detector for detecting the left-right and up-down alignment states, a detector (e.g., a second detector) for detecting the anterior-posterior alignment state is provided. For example, with respect to the optical axis of the inspection means located in the frontal direction of the eye under examination, the angle between the optical axis of the second indicator projection means and the optical axis of the indicator detection means having the second detector is set to an angle from which the indicator projection light and the light returned from the eye under examination can pass through the light guide optical system.

[0028] [Examples] An embodiment of the optometry device according to this embodiment will be described. Figure 1 is a diagram showing the schematic configuration of the external appearance of the optometry device 1. The optometry device 1 may be any optometry device equipped with an examination means for examining the eye to be examined, for example, a measuring device for measuring the optical properties of the eye to be examined, a device for photographing the anterior segment of the eye to be examined, a device for photographing the fundus of the eye to be examined, an OCT device for photographing a tomographic image of the fundus of the eye to be examined, etc. In this embodiment, the optometry device 1 will be described as an example of a device equipped with an objective measuring unit for objectively measuring the optical properties (e.g., refractive power) of the eye to be examined and a subjective measuring unit for subjectively measuring the optical properties (e.g., refractive power) of the eye to be examined. In the following description, the term "measurement" may be read as "examination".

[0029] In Figure 1, the left-right direction (horizontal direction) is described as the X direction, the up-down direction (vertical direction) as the Y direction, and the front-back direction (working distance direction) as the Z direction, from the perspective of the subject.

[0030] For example, the optometry device 1 includes a housing 2, a display window 3, a forehead rest 4, a chin rest 5, a controller 6, and an example of an examination means such as a measuring unit 7, an imaging unit 90, an anterior segment illumination unit 92, etc.

[0031] The presentation window 3 is used to present the target to the eye being examined. The forehead rest 4, on which the subject's forehead rests, is used to maintain a constant distance between the eye being examined and the optometric device 1. The chin rest 5, on which the subject's chin rests, is used to maintain a constant distance between the eye being examined and the optometric device 1. Note that the chin rest 5 is not necessarily required.

[0032] The controller 6, an example of an operating unit, includes a display 6a, a switch unit 6b, and other display means. The display 6a displays various information (for example, the measurement results of the eye being examined). The display 6a has a touch panel function, and the display 6a also functions as the switch unit 6b. The switch unit 6b may be used to perform various settings (for example, inputting operation signals to various locations). Signals corresponding to operation instructions from the controller 6 are output to the control unit 70 (see Figure 6), which will be described later, by at least one of wired communication via a cable or the like, and wireless communication via infrared or the like.

[0033] The imaging unit 90 includes an imaging optical system (not shown). For example, the imaging optical system is used to image the face of the subject. For example, the imaging optical system may consist of an image sensor and a lens. The anterior segment illumination unit 92 has an infrared illumination light source (not shown) arranged inside and emits illumination light toward the left and right subject eyes for imaging the anterior segment of the subject eye by the observation optical system 50 (see Figure 2), which will be described later.

[0034] <Measurement part> The measurement unit 7 comprises a left eye measurement unit 7L and a right eye measurement unit 7R. In this embodiment, the left eye measurement unit 7L and the right eye measurement unit 7R are made of the same material. Of course, the left eye measurement unit 7L and the right eye measurement unit 7R may be made of different materials, at least in part. The measurement unit 7 has a pair of left and right target projection optical systems, a pair of left and right subjective measurement units, and a pair of left and right objective measurement units, which will be described later. Alignment light, target light beam, and measurement light beam from the measurement unit 7 are guided to the eye under examination via the presentation window 3.

[0035] Figure 2 shows the optical system arranged in the measurement unit 7. In Figure 2, the left eye measurement unit 7L is given as an example of the measurement unit 7. The right eye measurement unit 7R has the same configuration as the left eye measurement unit 7L and is therefore omitted. For example, the left eye measurement unit 7L includes a target projection optical system 30, a subjective measurement optical system 25, an objective measurement optical system 10, an observation optical system 50, an alignment detection optical system 50A, etc. The subjective measurement optical system 25 and the objective measurement optical system 10 are examples of inspection optical systems.

[0036] <Visual Target Projection Optical System> The target projection optical system 30 projects the target light beam onto the eye under examination. For example, the target projection optical system 30 includes a display 31, a projection lens 33, a projection lens 34, a reflective mirror 36, an objective lens 37, a dichroic mirror 35, a dichroic mirror 29, and the like.

[0037] The display 31 shows a visual target (fixation target, test target, etc.). The visual target light beam emitted from the display 31 passes sequentially through the optical components from the projection lens 33 to the dichroic mirror 29 and is projected onto the left eye E under examination. The dichroic mirror 35 makes the optical path of the objective measurement optical system 10 and the optical path of the subjective measurement optical system 25 a common optical path. That is, the dichroic mirror 35 makes the optical axis L1 of the objective measurement optical system 10 and the optical axis L2 of the subjective measurement optical system 25 coaxial. The dichroic mirror 29 is an optical path branching member. The dichroic mirror 29 reflects the visual target light beam from the visual target projection optical system 30 and the measurement light beam from the projection optical system 10a (described later) and guides them to the eye E under examination.

[0038] <Subjective measurement optical system> The subjective measurement optical system 25 is used as part of the configuration of a subjective measurement unit that subjectively measures the optical characteristics of the eye E under examination. In this embodiment, the subjective measurement unit that measures the refractive power of the eye E under examination is given as an example of the optical characteristics of the eye E under examination. In addition to refractive power, the optical characteristics of the eye E under examination may also be contrast sensitivity, binocular vision function (e.g., amount of strabismus, stereopsis function, etc.), etc. For example, the subjective measurement optical system 25 is composed of the aforementioned target projection optical system 30 and the corrective optical system 60.

[0039] <Correction optical system> The corrective optical system 60 is positioned in the optical path of the target projection optical system 30. The corrective optical system 60 also changes the optical properties of the target light beam from the display 31. As a result, for example, the corrective optical system 60 changes the amount of refractive power (spherical refractive power, astigmatic refractive power) applied to the eye under examination. For example, the corrective optical system 60 includes an astigmatic correction optical system 63, a drive mechanism 39 used as a spherical correction optical system, and so on.

[0040] The astigmatism correction optical system 63 is used to correct the astigmatism power (cylindrical power) and astigmatism axis angle of the eye E under examination. In this embodiment, the astigmatism correction optical system 63 is positioned between the projection lens 33 and the projection lens 34. The astigmatism correction optical system 63 consists of two positive cylindrical lenses 61a and 61b with equal focal lengths. The cylindrical lenses 61a and 61b rotate independently around the optical axis L2 by the driving of the rotation mechanism 62a and the rotation mechanism 62b.

[0041] In this embodiment, the astigmatism correction optical system 63 was described using a configuration with cylindrical lenses 61a and 61b as an example, but it is not limited to this. The astigmatism correction optical system 63 can be configured to correct cylindrical power, astigmatism axis angle, etc. For example, the corrective lenses may be inserted into and removed from the optical path of the target projection optical system 30.

[0042] In this embodiment, the display 31 of the target projection optical system 30 is moved in the direction of the optical axis L2 of the target projection optical system 30 by a drive mechanism 39. For example, the drive mechanism 39 is composed of a motor and a slide mechanism. For example, during subjective measurement, the movement of the display 31 optically changes the presentation position (presentation distance) of the target to the eye being examined, and corrects the spherical refractive power of the eye being examined. In other words, in this embodiment, the movement of the display 31 constitutes a spherical power correction optical system. Then, the movement of the display 31 allows the spherical power to be measured based on the optical distance of the test target relative to the reference position.

[0043] However, the spherical power correction optical system is not limited to this. For example, the spherical power correction optical system may have a large number of optical elements, and the correction may be performed by arranging the optical elements in the optical path. Alternatively, for example, the system may be configured to move a lens placed in the optical path along the optical axis.

[0044] <Objective measurement optical system> An example of an inspection optical system is the objective measurement optical system 10, which is used as part of the configuration of an objective measurement unit that objectively measures the optical properties of the eye E under examination. In this embodiment, the objective measurement unit that measures the refractive power of the eye E under examination will be used as an example to describe the optical properties of the eye E under examination. For example, the objective measurement optical system 10 is composed of a projection optical system 10a and a light-receiving optical system 10b.

[0045] The projection optical system 10a projects a spot-shaped measurement indicator onto the fundus of the eye E through the center of the pupil of the eye E being examined. For example, the projection optical system 10a includes a light source 11, a relay lens 12, a hall mirror 13, a prism 15, an objective lens 14, a dichroic mirror 35, a dichroic mirror 29, etc. For example, the dichroic mirror 35 transmits light wavelengths less than 750 nm and reflects light wavelengths of 750 nm or more. For example, the dichroic mirror 29 reflects light wavelengths less than 910 nm and transmits light wavelengths of 910 nm or more.

[0046] The light source 11 is, for example, an SLD (superluminescent diode) that emits a measurement light beam with a wavelength centered at 880 nm. The light source 11 is conjugate to the fundus of the eye under examination E. The hole portion of the hole mirror 13 is conjugate to the pupil of the eye under examination E. The prism 15 is a light beam deflection member. The prism 15 is positioned away from the position conjugate to the pupil of the eye under examination E, and eccentricates the measurement light beam passing through the prism 15 with respect to the optical axis L1. The prism 15 is rotationally driven by a drive unit (e.g., a motor) 23 around the optical axis L1.

[0047] The light-receiving optical system 10b extracts the retinal reflected light beam reflected from the fundus of the eye under examination E in a ring shape via the periphery of the pupil of the eye under examination E. For example, the light-receiving optical system 10b includes a dichroic mirror 29, a dichroic mirror 35, an objective lens 14, a prism 15, a hall mirror 13, a relay lens 16, a mirror 17, a light-receiving diaphragm 18, a collimator lens 19, a ring lens 20, an image sensor 22 which is an example of an inspection light-receiving element, and so on.

[0048] The ring lens 20 consists of a ring-shaped lens portion and a light-shielding portion in which a light-shielding coating is applied to the area other than the lens portion. The ring lens 20 is optically conjugate to the pupil of the eye E under examination. The light-receiving aperture 18 and the image sensor 22 are conjugate to the fundus of the eye E under examination. The output from the image sensor 22 is input to the control unit 70.

[0049] In the above configuration, the measurement light beam emitted from the light source 11 passes sequentially through the optical components from the relay lens 12, the hall mirror 13, and the prism 15 to the dichroic mirror 29, forming a spot-shaped point light source image on the fundus of the eye E under examination. At this time, the pupil projection image (projected light beam on the pupil) in the hall portion of the hall mirror 13 is rapidly eccentrically rotated by the prism 15, which rotates around the optical axis. The point light source image projected onto the fundus is reflected and scattered and emitted as return light from the eye E under examination, reflected by the dichroic mirror 29 and the dichroic mirror 35, focused by the objective lens 102, and then focused again on the light receiving aperture 18 via the rapidly rotating prism 15, hall mirror 13, relay lens 16, and mirror 17. Subsequently, the return light from the eye E under examination is imaged as a ring-shaped image on the image sensor 22 by the collimator lens 19 and the ring lens 20.

[0050] The dichroic mirror 29 has wavelength-selective properties, for example, it reflects light with a wavelength less than 910 nm and transmits light with a wavelength of 910 nm or more. As a result, the dichroic mirror 29 transmits the alignment light (for example, with a wavelength of 940 nm) from the alignment optical system 50A described later, and reflects the measurement light with a wavelength of 880 nm. In other words, the dichroic mirror 29 functions as a wavelength-limiting member that restricts the wavelength of the reflected light from the eye under examination of the light sources 56 and 41 used for alignment from entering the image sensor 22. Also, the anterior segment illumination unit 92 shown in Figure 1 emits near-infrared light with a wavelength of around 940 nm, similar to the alignment light, so this illumination light is also restricted from entering the image sensor 22 by the dichroic mirror 29. In other words, the dichroic mirror 29 allows the wavelength of the measurement light to pass through (reflect in this case), but blocks the wavelength of the alignment light (indicators for light sources 56 and 41), thereby limiting the incidence of alignment light into the optical path where the image sensor 22 is located.

[0051] In this embodiment, the prism 15 is positioned on the common optical axis of the projection optical system 10a and the light-receiving optical system 10b. For example, the measurement light beam from the projection optical system 10a passes through the prism 15 and enters the eye E under examination, and the fundus-reflected light beam reflected from the fundus of the eye E under examination also passes through the same prism 15. Therefore, subsequent optical systems are scanned in reverse as if there were no eccentricity of the projected light beam and fundus-reflected light beam (receiving light beam) above the pupil.

[0052] The optical system for measuring ocular refractive power, which is an example of the objective measurement optical system 10, is not limited to the above, as long as it can obtain ocular refractive power. For example, it may be a configuration that includes a Shack-Hartmann sensor. For further details, please refer to, for example, Japanese Patent Application Publication No. 2018-47049.

[0053] Furthermore, the light source 11 and relay lens 12 of the projection optical system 10a, and the light receiving aperture 18, collimator lens 19, ring lens 20, and image sensor 22 of the light receiving optical system 10b are all integrally movable in the optical axis direction. In this embodiment, these are moved synchronously and integrally as a drive unit 95 by a drive mechanism 39 that moves the display 31. The movement position of the drive unit 95 moved by the drive mechanism 39 is detected by a detector (not shown). Of course, these may also be configured to be driven individually.

[0054] As the drive unit 95 moves in the optical axis direction, the light source 11, the light-receiving aperture 18, and the image sensor 22 are positioned so as to be optically conjugate with respect to the fundus of the eye E being examined. Regardless of the movement of the drive unit 95, the hall mirror 13 and the ring lens 20 are positioned so as to be conjugate with the pupil of the eye E being examined at a constant magnification. Therefore, the fundus reflected light beam, which is the measurement light beam from the projection optical system 10a reflected, always enters the ring lens 20 of the light-receiving optical system 10b as a parallel light beam, and regardless of the refractive power of the eye E being examined, a ring-shaped light beam of the same size as the ring lens 20 is captured in focus on the image sensor 22.

[0055] <Observation Optical System> The observation optical system (imaging optical system) 50 includes a dichroic mirror 29, an objective lens 53, an imaging lens 51, an image sensor 52, etc. The dichroic mirror 29 transmits anterior segment observation light and alignment light. The image sensor 52 has an imaging surface positioned conjugate to the anterior segment of the eye under examination E. An area sensor is used for the image sensor 52. The output from the image sensor 52 is input to the control unit 70. As a result, an anterior segment image of the eye under examination E is captured by the image sensor 52 and displayed on the display 6a.

[0056] Here, the dichroic mirror 29 functions as a wavelength limiting member that restricts the reflected light of the measurement light from the eye under examination from entering the image sensor 52 due to its wavelength transmission characteristics as described above. In other words, the dichroic mirror 29 allows the wavelength of the alignment light to pass through (transmits in this case) but blocks the wavelength of the measurement light, thereby also serving as a member that limits the incidence of the measurement light into the optical path where the image sensor 52 is located.

[0057] <Alignment detection optics> The alignment detection optical system 50A is used to detect the alignment state of the measurement unit 7 (left eye measurement unit 7L in Figure 2) with respect to the eye E (left eye EL in Figure 2). The alignment detection optical system 50A comprises a first index projection optical system 55, an observation optical system 50 which also serves as the first detection optical system, a second index projection optical system 40a, and a second detection optical system 40b.

[0058] The first indicator projection optical system 55 projects a first indicator for aligning the measurement unit 7 in the XY direction with respect to the eye E under examination. The first indicator projection optical system 55 comprises a light source 56 that emits near-infrared light (for example, wavelength 940 nm), a collimator lens 57, and a half mirror 58. The light emitted from the light source 56 is made into a nearly parallel beam by the collimator lens 57 and reflected by the half mirror 58 to be coaxial with the optical axis L3 of the observation optical system 50. Subsequently, the light from the light source 56 passes through the dichroic mirror 29 and is projected onto the eye E under examination from the front direction.

[0059] The observation optical system 50 also serves as a first detection optical system for detecting the first indicator projected onto the eye E under examination. Specifically, light from the light source 56 of the first indicator projection optical system 55 is reflected by the cornea of ​​the eye E under examination, forming an indicator (corneal reflection spot), which is a virtual image of the light source 56. The reflected light from the eye E under examination passes through the dichroic mirror 29 and is received by the image sensor 52, which is an example of a detector, via the half mirror 58, objective lens 53, and imaging lens 51. Based on the output signal from the image sensor 52, the position of the indicator is analyzed by the control unit 70, thereby detecting the alignment state of the eye E under examination in the XY direction.

[0060] The second index projection optical system 40a includes a light source 41 that emits near-infrared light (for example, wavelength 940 nm) and a collimator lens 42, and projects an index obliquely toward the cornea of ​​the eye E under examination. The wavelength of the near-infrared light emitted by the light source 41 overlaps, at least partially, with the wavelength of the light emitted by the light source 56 of the first index projection optical system 55.

[0061] The second detection optical system 40b detects the index projected onto the eye E under examination by the second index projection optical system 40a. The second detection optical system 40b comprises a lens 46, a focusing lens 47, and an image sensor 48, which is an example of a detector. For example, an area sensor is used for the image sensor 48. Light from the light source 41 is reflected by the cornea of ​​the eye E under examination, forming an index (corneal reflection spot), which is a virtual image of the light source 41. The light from this index enters the image sensor 48 via the lens 46 and the focusing lens 47. The position of the index on the image sensor 48 changes according to the position of the eye E under examination in the Z direction. The output signal from the image sensor 48 is output to the control unit 70, which detects the alignment state of the eye E under examination in the Z direction.

[0062] Here, the lens 46 (or possibly the focusing lens 47) has the same properties as the dichroic mirror 29: it reflects light with a wavelength less than 910 nm and transmits light with a wavelength of 910 nm or more. As a result, the reflected light from the eye of the light source 41 can pass through the lens 46 and be incident on the image sensor 48. On the other hand, the reflected light from the eye of the measurement light from the light source 11 and visible light, which become noise light for alignment detection, are restricted from being incident on the image sensor 48 by the wavelength-selective properties of the lens 46. In other words, the lens 46 with wavelength-selective properties functions as a wavelength-limiting member that restricts the reflected light from the eye of the measurement light from being incident on the image sensor 48. To put it another way, the lens 46 allows the wavelength of the alignment indicator from the light source 41 to pass through, but blocks the wavelength of the measurement light, thereby limiting the incidence of the measurement light into the optical path where the image sensor 48 is located.

[0063] The optical axis of the second detection optical system 40b is positioned symmetrically with respect to the optical axis of the second index projection optical system 40a with respect to the optical axis L3 of the observation optical system 50 (which is also the optical axis L2 of the measurement optical system 10, which is coaxial with optical axis L3). The angle α of the optical axes of the second index projection optical system 40a and the second detection optical system 40b with respect to optical axis L3 is set to an angle that allows the index projection light from the light source 41 and the reflected light from the eye under examination E to pass through the concave mirror 85 of the light guide optical system 80, which will be described later. For example, the angle α is 10 degrees or less, and in this disclosure, the angle α is set to 6 degrees. The image sensor 48 of the second detection optical system 40b can detect the alignment state in the Z direction with the required accuracy even with such a narrow angle α for the projection optical axis and detection optical axis.

[0064] <Internal configuration and light guide optics of the ophthalmoscopic device> The internal configuration of the optometric device 1 will now be described. Figure 3 is a schematic diagram of the internal configuration of the optometric device 1 viewed from the front. Figure 4 is a schematic diagram of the internal configuration of the optometric device 1 viewed from the side. Figure 5 is a schematic diagram of the internal configuration of the optometric device 1 viewed from above. Note that in Figures 4 and 5, for the sake of explanation, only the optical axis of the left eye measuring unit 7L is shown.

[0065] The optometry device 1 includes a light-guiding optical system 80 that guides the image of the target light beam from the measuring unit 7 to the eye under examination. The light-guiding optical system 80 in this embodiment includes, for example, a deflection mirror 81, a reflection mirror 84, a concave mirror 85, etc., which are examples of light deflection members. The optometry device 1 also includes a drive mechanism 82 and a drive unit 83 as components related to the light-guiding optical system 80.

[0066] The concave mirror 85 is equivalent to the optical system of the measurement unit 7 (alignment detection optical system 50A, objective measurement optical system 10, etc.) being optically positioned at a predetermined working distance in front of the eye when alignment is completed. The optometry device 1 is configured such that the light guide optical system 80, with the concave mirror 85 of the light guide optical member, allows alignment and measurement to be performed with an open view in front of the subject's eyes without having to position the optical system of the measurement unit 7 in front of the subject's eyes. Furthermore, during subjective measurement, the light guide optical system 80 guides the image of the target light beam via the corrective optical system 60 to the subject's eye so that it is optically at a predetermined examination distance.

[0067] The light guide optical system 80 is not limited to this configuration. For example, the light guide optical system 80 may have a configuration without a reflective mirror 84. In this case, the target light beam from the measuring unit 7 may be illuminated from an oblique direction to the optical axis L of the concave mirror 85 after passing through the deflection mirror 81. Alternatively, the light guide optical system 80 may have a configuration with a half mirror. In this case, the target light beam from the measuring unit 7 may be illuminated from an oblique direction to the optical axis L of the concave mirror 85 via the half mirror, and the reflected light beam may be guided to the eye E under examination.

[0068] The optometry device 1 has a left eye drive unit 9L and a right eye drive unit 9R, and the left eye measuring unit 7L and the right eye measuring unit 7R can be moved in the X direction (horizontal direction). For example, by moving the left eye measuring unit 7L and the right eye measuring unit 7R in the X direction, the distance between the measuring unit 7 and the deflection mirror 81 described later changes, and the presentation position of the target light beam from the measuring unit 7 in the Z direction (front-to-back direction relative to the subject) is changed. As a result, the measuring unit 7 is adjusted in the Z direction so that the target light beam corrected by the corrective optical system 60 is guided to the eye E under examination, and an image of the target light beam corrected by the corrective optical system 60 is formed on the fundus of the eye E under examination.

[0069] For example, the deflection mirror 81 has a pair of right-eye deflection mirrors 81R and left-eye deflection mirrors 81L, each provided on the left and right sides. For example, the deflection mirror 81 is positioned between the measurement unit 7 and the eye under test E. In this embodiment, the deflection mirror 81R is positioned between the measurement unit 7R and the eye under test ER, and the deflection mirror 81L is positioned between the measurement unit 7L and the eye under test EL. That is, the deflection mirror 81 is positioned in the shared optical path of the objective optical system 10 and the target projection optical system 30 of the measurement unit 7. The deflection mirror 81 is also positioned in the optical path of the subjective measurement optical system 25. It is preferable that the deflection mirror 81 be positioned at the pupil conjugate position.

[0070] For example, the left eye deflection mirror 81L reflects the light beam projected from the left eye measuring unit 7L and guides it to the left eye EL. Also, for example, the left eye deflection mirror 81L reflects the fundus-reflected light beam from the left eye EL and guides it to the left eye measuring unit 7L. For example, the right eye deflection mirror 81R reflects the light beam projected from the right eye measuring unit 7R and guides it to the right eye ER. Also, for example, the right eye deflection mirror 81R reflects the fundus-reflected light beam from the right eye ER and guides it to the right eye measuring unit 7R. In this embodiment, a configuration in which a deflection mirror 81 is used as a deflection member that reflects the light beam projected from the measuring unit 7 to the eye under examination E and guides it is described as an example, but it is not limited to this. The deflection member only needs to be able to reflect the light beam projected from the measuring unit 7 to the eye under examination E and guide it, and may be, for example, a prism, a lens, etc.

[0071] For example, the drive mechanism 82 consists of a motor (drive unit) or the like. For example, the drive mechanism 82 has a drive mechanism 82L for driving the left eye deflection mirror 81L and a drive mechanism 82R for driving the right eye deflection mirror 81R. For example, the deflection mirror 81 rotates when driven by the drive mechanism 82. For example, the drive mechanism 82 rotates the deflection mirror 81 with respect to a rotation axis in the horizontal direction (X direction) and a rotation axis in the vertical direction (Y direction). That is, the drive mechanism 82 rotates the deflection mirror 81 in the XY direction. Note that the rotation of the deflection mirror 81 may be in either the horizontal or vertical direction.

[0072] For example, the drive unit 83 consists of a motor or the like. For example, the drive unit 83 has a drive unit 83L for driving the left eye deflection mirror 81L and a drive unit 83R for driving the right eye deflection mirror 81R. For example, the deflection mirror 81 moves in the X direction by the drive of the drive unit 83. For example, by moving the left eye deflection mirror 81L and the right eye deflection mirror 81R, the distance between the left eye deflection mirror 81L and the right eye deflection mirror 81R is changed, and the distance in the X direction between the left eye optical path and the right eye optical path can be changed to match the interpupillary distance of the eye E under examination.

[0073] Furthermore, for example, multiple deflection mirrors 81 may be provided in both the left eye optical path and the right eye optical path. For example, one configuration may involve providing two deflection mirrors in both the left eye optical path and the right eye optical path (for example, a configuration where two deflection mirrors are provided in the left eye optical path). In this case, one deflection mirror may be rotated in the X direction and the other deflection mirror may be rotated in the Y direction. For example, by rotating the deflection mirror 81, the apparent light beam for forming the image of the target light beam in front of the eye E under examination can be deflected, and the formation position of the image of the target light beam can be optically corrected.

[0074] For example, the concave mirror 85 is shared by the left eye measuring unit 7L and the right eye measuring unit 7R. For example, the concave mirror 85 is shared by the left eye optical path including the left eye corrective optical system and the right eye optical path including the right eye corrective optical system. That is, the concave mirror 85 is positioned so that it passes through both the left eye optical path including the left eye corrective optical system and the right eye optical path including the right eye corrective optical system. Of course, the concave mirror 85 does not have to be configured to be shared by the left eye optical path and the right eye optical path. For example, a concave mirror may be provided in each of the left eye optical path including the left eye corrective optical system and the right eye optical path including the right eye corrective optical system. For example, the concave mirror 85 guides the target light beam corrected by the corrective optical system 60 to the eye under examination E so that it is optically at a predetermined examination distance. In other words, the light-guiding optical system 80, which includes the concave mirror 85, allows the area in front of the subject's eyes to be left open without having to place the corrective optical system 60 in front of the subject's eyes.

[0075] For example, the concave mirror 85 is used for both the subjective measurement unit and the objective measurement unit. For example, the target light beam projected from the subjective measurement optical system 25 is projected onto the eye under examination via the concave mirror 85. Also, for example, the measurement light projected from the objective measurement optical system 10 is projected onto the eye under examination via the concave mirror 85. Also, for example, the reflected light of the measurement light projected from the objective measurement optical system 10 is guided to the light-receiving optical system 10b of the objective measurement optical system 10 via the concave mirror 85. In this embodiment, the configuration in which the reflected light of the measurement light from the objective measurement optical system 10 is guided to the light-receiving optical system 10b of the objective measurement optical system 10 via the concave mirror 85 is given as an example, but the system is not limited to this. The reflected light of the measurement light from the objective measurement optical system 10 may be configured not to pass through the concave mirror 85.

[0076] <Optical path of the self-aware measurement unit> The optical path of the subjective measurement unit will now be explained. The subjective measurement unit guides the target light beam, which has passed through the corrective optical system 60, towards the eye under examination by a concave mirror 85, thereby forming an image of the target light beam that has passed through the corrective optical system 60 in front of the subject's eye at a predetermined examination distance. In other words, the concave mirror 85 reflects the target light beam so that it becomes a nearly parallel light beam. Therefore, the target image as seen by the subject appears to be further away than the actual distance from the eye under examination E to the display 31. That is, by using the concave mirror 85, the target image can be presented to the subject so that the image of the target light beam is visible at a predetermined examination distance.

[0077] Let's explain in more detail. In the following explanation, we will use the left eye optical path as an example. The right eye optical path has the same configuration as the left eye optical path. For example, in subjective measurement for the left eye, the target light beam projected from the display 13 of the left eye measurement unit 7L enters the astigmatism correction optical system 63 via the projection lens 33. The target light beam that has passed through the astigmatism correction optical system 63 is projected from the left eye measurement unit 7L toward the left eye deflection mirror 81L via the reflective mirror 36, dichroic mirror 35, and dichroic mirror 29. The target light beam emitted from the left eye measurement unit 7L and reflected by the left eye deflection mirror 81 is reflected toward the concave mirror 85 by the reflective mirror 84. The target light beam reflected by the concave mirror reaches the left eye EL.

[0078] As a result, a target image corrected by the corrective optical system 60 is formed on the fundus of the left eye EL, based on the position where the subject's left eye EL is fitted with glasses (for example, about 12 mm from the corneal apex). Therefore, it is equivalent to the astigmatism correcting optical system 63 being positioned in front of the eye, and the spherical power adjustment by the spherical power correcting optical system (in this embodiment, the driving mechanism 39) being performed in front of the eye, allowing the subject to sight the target image in a natural, open state via the concave mirror 85. The optical path for the right eye is configured similarly to the optical path for the left eye, and a target image corrected by a pair of corrective optical systems 60 is formed on the fundus of both eyes, based on the position where the left and right eyes E are fitted with glasses (for example, about 12 mm from the corneal apex). In this way, the subject looks directly at the target in a natural state of vision and responds to the examiner, correcting with the corrective optical system 60 until the test target appears properly, and the optical characteristics of the eye are subjectively measured based on the corrected value.

[0079] <Optical path of the objective measurement unit> The optical path of the objective measurement unit will be explained below. In the following explanation, the optical path for the left eye will be used as an example, but the optical path for the right eye has the same configuration as the optical path for the left eye. For example, in the objective measurement unit for the left eye, the measurement light emitted from the light source 11 of the projection optical system 10a in the objective measurement optical system 10 passes through the relay lens 12 and the dichroic mirror 29, and is projected from the left eye measurement unit 7L toward the left eye deflection mirror 81L. The measurement light emitted from the left eye measurement unit 7L and reflected by the left eye deflection mirror 81 is reflected by the reflection mirror 84 toward the concave mirror 85. The measurement light reflected by the concave mirror reaches the left eye EL, forming a spot-shaped point light source image on the fundus of the left eye EL. At this time, the pupil projection image (projected light beam on the pupil) of the hole portion of the hole mirror 13 is rapidly eccentrically rotated by the prism 15 rotating around the optical axis.

[0080] Light from a point light source formed on the fundus of the left eye EL is reflected and scattered, exiting the eye E under test, and is focused by the objective lens 14 via the optical path through which the measurement light passed, reaching the prism 15, hall mirror 13, relay lens 16, and mirror 17. The light reflected by the mirror 17 is focused again at the aperture of the light receiving diaphragm 18, made into a nearly parallel beam (in the case of an emmetropic eye) by the collimator lens 19, extracted as a ring-shaped beam by the ring lens 20, and received as a ring image by the image sensor 22. By analyzing the received ring image, the optical properties of the eye E under test can be objectively measured.

[0081] <Department Head> Figure 6 shows the control system of the optometry device 1. For example, the control unit 70 is connected to various electrical elements such as the imaging unit 90, the anterior eye illumination unit 92, the display 6a and switch unit 6b of the controller 6, the light source 11, image sensor 22, display 31, image sensor 52, drive mechanism 39, rotation mechanism 62a, rotation mechanism 62b, the light source 56 of the first index projection optical system 55, the light source 41 and image sensor 48 of the second index projection optical system 40a, the drive mechanism 82 and drive unit 83 of the light guide optical system 80. The control unit 70 is also connected to a memory 75 (e.g., non-volatile memory), which is an example of a storage means, and a printer 77. For example, the memory 75 is a non-transient storage medium that can retain its contents even if the power supply is cut off. For example, a hard disk drive, flash ROM, USB memory, etc. can be used as the memory 75. The printer 77 prints out the measurement results.

[0082] For example, the control unit 70 includes a CPU (processor), RAM, ROM, etc. For example, the CPU controls each component in the optometry device 1. For example, RAM temporarily stores various types of information. For example, ROM stores various programs for controlling the operation of the optometry device 1, visual targets, initial values, etc. The control unit 70 may be composed of multiple control units (i.e., multiple processors). The control unit 70 may also include an FPGA (field-programmable gate array) 70a. The FPGA 70a allows the device designer to freely configure the control configuration. Furthermore, the control unit 70 also functions as a display control means for controlling the display on display 6a and the display on display 31. In addition, the control unit 70 also functions as a measurement control means for controlling the drive system (drive mechanism 39, rotation mechanism 62a, rotation mechanism 62b) of the corrective optical system 60. Furthermore, the control unit 70 also functions as an alignment control means for controlling the drive mechanism 82 and drive unit 83 of the light guide optical system 80.

[0083] <Operation> The operation of the optometry device 1, which has the above configuration, will now be explained. The subject places their forehead on the forehead rest 4 and observes the presentation window 3. Once the subject is ready for examination, the examiner operates the touch panel (or switch unit 6b) of the controller 6's display 6a to input a selection signal for a fixation target (fixation target) to fixate on the subject eye E. The control unit 70 displays the same target based on the target selection signal on the displays 31 provided in the left eye measurement unit 7L and the right eye measurement unit 7R, respectively. Although a target is presented to each of the left and right subject eyes E (left eye EL and right eye ER), the subject recognizes it as a single target for both eyes because the same target is presented. In the case of monocular measurement, the target is displayed only on the display 31 on the measurement eye side.

[0084] <Alignment of the measurement unit with respect to the eye being examined> Next, the examiner inputs a start signal via the touch panel (or switch unit 6b) of the display 6a to align the left eye measuring unit 7L and the right eye measuring unit 7R to the subject's left eye EL and right eye ER, respectively. Indices from the first indicator projection optical system 55 and the second indicator projection optical system 40a are projected onto the left eye EL and right eye ER, respectively. This activates an automatic alignment means that aligns the measuring unit 7, including the objective measuring optical system 10, etc., to a predetermined positional relationship in three dimensions with respect to the subject's eye E. The operation of the automatic alignment means will be described below.

[0085] The indicator projected onto the eye under examination by the first indicator projection optical system 55 using the light source 56 is received by the image sensor 52, and the alignment state of the measurement unit 7 in the XY direction is detected based on the output signal from the image sensor 52. In addition, the indicator projected onto the eye under examination by the second indicator projection optical system 40a using the light source 41 is received by the image sensor 48, and the alignment state of the measurement unit 7 in the Z direction is detected based on the output signal from the image sensor 48.

[0086] In this case, when imaging is performed using the image sensors 52 and 48 in the normal process, the image sensor 52 receives not only indicators (corneal reflection spots) from the light source 56 but also indicators (corneal reflection spots) from the light source 41. Therefore, it is difficult for the control unit 70 to distinguish only the indicators from the light source 56 and appropriately detect the alignment state in the XY direction. Furthermore, the image sensor 48 receives indicators from the light source 41, indicators from the light source 56, and illumination light from the anterior segment illumination unit 92. In this case as well, it is difficult for the control unit 70 to distinguish only the indicators from the light source 41 and appropriately detect the alignment state in the Z direction.

[0087] Therefore, the control unit 70 of this disclosure controls the timing of the exposure times of the image sensor 52 and the image sensor 48 so that the exposure times of the image sensor 52 and the image sensor 48 do not overlap in timing. For example, the control unit 70 controls the start timing of the exposure of the image sensor 52 and the image sensor 48. More preferably, the control unit 70 controls the exposure times of the image sensor 52 and the image sensor 48 at a time shorter than the frame interval (time of one frame) of a predetermined frame rate. Even more preferably, the control unit 70 adjusts the frame phase relationship of the exposure times of the image sensor 52 and the image sensor 48. The control unit 70 also controls the illumination of the light source 56 and the light source 41 in accordance with the exposure times of the image sensor 52 and the image sensor 48. If an anterior segment illumination unit 92 is used, the control unit 70 also controls the illumination of the anterior segment illumination unit 92 in accordance with the exposure times of the image sensor 52 and the image sensor 48.

[0088] Figure 7 illustrates an example of controlling the timing of exposure time for image sensors 52 and 48 (start and end of exposure timing), and the timing of lighting each light source (light source 56, light source 41, anterior eye illumination unit 92) (start and end of lighting timing). In Figure 7, figure G52 shows the time-series timing of the frame interval FR (time of one frame) and frame output Fo (output of exposed frames) of image sensor 52. For example, the frame rate of image sensor 52 is 30fps (number of frames per second), and its frame interval FR is approximately 33ms (milliseconds). Figure G48 shows the time-series timing of the frame interval FR and frame output Fo of image sensor 48. For example, the frame rate of image sensor 48 is 30fps, the same as image sensor 52, and its frame interval FR is approximately 33ms.

[0089] In Figure 7, the figure G52ET shows the timing of the exposure time Eta of the image sensor 52 relative to the frame interval FR of figure G52. The exposure time Eta of the image sensor 52 is shorter than the frame interval FR and is controlled by the FPGA 70a of the control unit 70 to half of the frame interval FR (approximately 16.6 ms). Also in Figure 7, the figure G48ET shows the timing of the exposure time Etb of the image sensor 48 relative to the frame interval FR of figure G48. The exposure time Etb of the image sensor 48 is also shorter than the frame interval FR and is controlled by the FPGA 70a to half of the frame interval FR (approximately 16.6 ms). Then, in order to prevent the exposure time Eta of the image sensor 52 and the exposure time Etb of the image sensor 48 from overlapping in timing, the FPGA 70a sets the amount of frame phase shift Ph of the image sensor 48 relative to the frame phase of the image sensor 52 to be equal to the exposure time Etb.

[0090] Furthermore, the on-time G56ON of the light source 56 used for XY alignment is controlled to synchronize with the exposure time Eta of the image sensor 52. In other words, during the exposure time Etb of the image sensor 48, the indicator by the first indicator projection optical system 55 (light source 56) is controlled not to be projected onto the eye under examination. Similarly, the on-time G92ON of the anterior segment illumination unit 92 used for anterior segment observation is also controlled to synchronize with the exposure time Eta of the image sensor 52. In other words, during the exposure time Etb of the image sensor 48, the eye under examination is controlled not to be illuminated by the anterior segment illumination unit 92. On the other hand, the on-time G41ON of the light source 41 used for Z alignment is controlled to synchronize with the exposure time Etb of the image sensor 48. In other words, during the exposure time Eta of the image sensor 52, the indicator by the second indicator projection optical system 40a (light source 41) is controlled not to be projected onto the eye under examination.

[0091] Through the control of the exposure time of the image sensors 52 and 48, and the control of the illumination of the light sources 56 and 41, the image sensor 52 receives an index from the light source 56 used for XY alignment, but not an index from the light source 41 used for Z alignment. Therefore, as shown in Figure 8, the control unit 70 analyzes the position of the index 56I captured on the image sensor 52, thereby appropriately detecting the XY alignment state of the measurement unit 7 with respect to the eye under examination. Figure 8 is an example of an image 52I captured on the image sensor 52, in which the index 56I formed by the reflection from the cornea of ​​the eye under examination is captured within the anterior segment image EFI of the eye under examination E, which is illuminated by the anterior segment illumination unit 92.

[0092] Furthermore, while the image sensor 48 receives an index from the light source 41 used for Z-direction alignment, it does not receive an index from the light source 56 or illumination light from the anterior segment illumination unit 95. Therefore, as shown in Figure 9, the control unit 70 analyzes the position of the index 41I captured on the image sensor 48, thereby appropriately detecting the Z-direction alignment state of the measurement unit 7 with respect to the eye under examination. Figure 9 shows an example of an image 48I captured on the image sensor 48. Since the anterior segment illumination unit 92 is turned off during the exposure time of the image sensor 48, the anterior segment image of the eye under examination E is not captured as shown in Figure 8, and an index 56I formed by the reflection of the cornea of ​​the eye under examination is captured against a dark background.

[0093] Furthermore, because the frame phase of the image sensor 48 is shifted relative to the frame phase of the image sensor 52, the images captured by the image sensor 52 and the image sensor 48 are not output simultaneously but sequentially, allowing for efficient analysis of each image.

[0094] The control unit 70 controls the drive of the drive mechanism 82 (82L, 82R) and drive unit 83 (83L, 83R) based on the detection result of the index 56I captured by the image sensor 52, and automatically adjusts the alignment in the XY direction. The control unit 70 also controls the drive of the drive unit 9 (9L, 9R) based on the detection result of the index 56I captured by the image sensor 48, and automatically adjusts the alignment in the Z direction. When the position of the index 56I falls within a predetermined tolerance range with respect to the reference position in the XY direction on the image sensor 52, and when the position of the index 56I falls within a predetermined tolerance range with respect to the reference position in the Z direction on the image sensor 48, the control unit 70 determines that the alignment of the measurement unit 7 with respect to the eye E under examination is complete. Then, once the alignment with respect to the eye E under examination is complete, the control unit 70 issues a trigger signal to start objective refractive power measurement (objective measurement) and automatically performs the eye refractive power measurement using the objective measurement optical system 10 (performs an auto shot).

[0095] The control unit 70 emits a measurement light beam from the objective measurement optical system 10. In this case, each measurement light beam is reflected by the concave mirror 85 via the deflection mirrors 81R and 81L, and then projected onto the fundus of the eye being examined. The measurement light reflected from the fundus is then captured by the image sensors 22 of the left and right measurement units 7 via the concave mirror 85 and the deflection mirrors 81R and 81L, and a measurement image is captured.

[0096] For example, in the measurement of objective refractive power, a preliminary measurement of the eye's refractive power is performed first, and based on the results of the preliminary measurement, the display 31 may be moved in the direction of the optical axis L2, thereby creating a haze over the eye E being examined. Subsequently, the main measurement of the eye's refractive power may be performed on the haze-covered eye. In the main measurement, the measurement image is captured by the image sensor 22, and the output signal from the image sensor 22 is stored in the memory 75 as image data (measurement image). Then, the control unit 70 performs image analysis on the ring image stored in the memory 75 to determine the refractive power values ​​in each meridian direction. The control unit 70 then applies predetermined processing to this refractive power to obtain the objective refractive power (objective value) of the eye's S (spherical power), C (astigmatism power), and A (astigmatism axis angle) when the eye is used for distance vision. The obtained objective value when the eye is used for distance vision is stored in the memory 75. The objective refractive power of the eye being examined may be measured simultaneously in both eyes, or separately in each eye.

[0097] The objective refractive power measurement is performed multiple times (for example, three times) for each of the left and right eyes being examined. During these multiple measurements, even after the alignment adjustment in the XYZ directions is completed, if the alignment state deviates from a predetermined tolerance range due to movement of the eye being examined, the control unit 70 controls the driving of the drive unit 9, drive mechanism 82, and drive unit 83 so that the alignment state returns to the predetermined tolerance range. In other words, automatic alignment tracking is performed.

[0098] In determining the completion of alignment and automatically tracking the alignment as described above, exposure of both image sensors 52 and 48 is performed within a frame interval (e.g., 33 ms), so that both indicator detection by image sensor 52 and indicator detection by image sensor 48 are performed at a predetermined frame rate (e.g., 30 fps). Therefore, even though the alignment state in the XYZ direction is detected using image sensors 52 and 48, the detection results of the indicators by light source 56 and light source 41 can be obtained within the same frame rate as when alignment detection is performed at the frame rate of a single image sensor 52. As a result, the determination of alignment completion can be made appropriately without delay in determining the alignment state.

[0099] Here, if we assume that light sources 56 and 41 are switched on alternately at a frame interval FR, and the exposure time of image sensors 52 and 48 is kept at the usual frame interval FR, then the detection of the indicator of light source 56 captured by image sensor 52 and the detection of the indicator of light source 41 captured by image sensor 48 will each occur at half the predetermined frame rate (e.g., 15 fps). In this case, nystagmus or blinking of the eye under examination may delay the determination of alignment completion, resulting in a delay in the timing of the measurement, which can easily affect the measurement results, such as leading to incorrect measurement values. In contrast, in this disclosure, as described above, the detection of the indicator of light source 56 captured by image sensor 52 and the detection of the indicator of light source 41 captured by image sensor 48 are each performed at a predetermined frame rate (e.g., 30 fps). Therefore, the completion of alignment can be determined in a timely manner, and the measurement can be performed without delay in the timing of the measurement execution. As a result, highly reliable measurement results can be obtained without reducing the accuracy of the measurement results.

[0100] In this embodiment, the configuration described as adjusting the alignment in the XYZ directions by driving the deflection mirror 81 with the drive mechanism 82 and the drive unit 83, and moving the measurement unit 7 with the drive unit 9L and the drive unit 9R, is not limited to this. Any configuration that can adjust the positional relationship between the eye under examination and the measurement unit 7 is acceptable. For example, a configuration may be provided in which the housing 2 on which the measurement unit 7 is arranged can be moved in the XYZ directions relative to the chin rest 6, and the housing 2 can be moved. In this case, it is preferable to provide a configuration in which the deflection mirror 81L for the left eye and the deflection mirror 81R for the right eye can be moved in the X direction, respectively. This makes it possible to adjust the left-right direction of the optical axes of the measurement unit 7L and the measurement unit 7R in accordance with the interpupillary distance of the subject. Alternatively, for example, a configuration may be provided in which the XYZ direction adjustment can be performed by the deflection mirror 81 alone. In this case, for example, the deflection mirror 81 can be rotated, and the deflection mirror 81 can be moved in the Z direction so as to change the distance between it and the measurement unit 7.

[0101] <Example of transformation> Although typical embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible.

[0102] For example, in the explanation of Figure 7 above, the exposure time Eta of the image sensor 52 and the exposure time Etb of the image sensor 48 were set to half the frame interval FR, but this is not limited to this. The exposure times Eta and Etb can be shorter than the frame interval FR, as long as the sum of the exposure times Eta and Etb is less than or equal to the frame interval FR. For example, if the brightness of the index 56I (index from light source 56) captured by the image sensor 52 is lower than the brightness of the index 41I (index from light source 41) captured by the image sensor 48, and the detection accuracy of index 56I by image analysis decreases, the exposure time Eta of the image sensor 52 can be made longer than the exposure time Etb of the image sensor 48 so that the brightness of index 41I increases. For example, the exposure time Eta may be set to 2 / 3 of the frame interval FR (for example, about 22.2 ms), and the exposure time Etb may be set to 1 / 3 of the frame interval FR (for example, about 11.1 ms). Furthermore, the frame phase shift amount Ph of the image sensor 48 is set to be the same as the exposure time Etb. The illumination time G56ON of the light source 56 and the illumination time G92ON of the anterior segment illumination unit 92 are controlled to synchronize with the exposure time Eta of the image sensor 52, and the illumination time G41ON of the light source 41 is controlled to synchronize with the exposure time Etb of the image sensor 48. As a result, the index 56I is increased, and the alignment state is detected more appropriately.

[0103] Furthermore, in the explanation of Figure 7 above, the timing of the exposure time Eta of image sensor 52 and the exposure time Etb of image sensor 48 with respect to the frame interval FR is set to immediately before the frame output Fo, but this is not limited to this. For example, if a control can be constructed that allows arbitrary changes to the timing of the exposure times of image sensors 52 and 48 within the frame interval FR, it is not necessary to shift the frame phase relationship between image sensors 52 and 48. For example, the exposure time Eta of image sensor 52 could be set to the first half of the frame interval FR, and the exposure time Etb of image sensor 48 could be set to the second half of the frame interval FR.

[0104] Furthermore, in the explanation of Figure 2 above, the detector of the second detection optical system 40b was shown as the image sensor 48 of the area sensor. However, since detection is performed in one direction in the front-to-back direction (Z direction), the detector of the second detection optical system 40b may also be a line sensor. Even when a line sensor is used, its exposure time should be controlled to be the same as the exposure time Etb of the image sensor 48 shown in Figure 7. The line sensor can be treated as one of the horizontal lines of the image sensor 48, which is an area sensor. Therefore, by setting the exposure time of the line sensor to be the same as the exposure time Etb of the image sensor 48, it is possible to detect an indicator with the same brightness as the indicator detected by the image sensor 48, and the alignment state can be judged more appropriately.

[0105] When using a line sensor, it is preferable to replace the focusing lens 47 of the second detection optical system 40b with a cylindrical lens. The cylindrical axis of the cylindrical lens should be positioned so that the indicator light beam, which focuses in a line, is perpendicular to the longitudinal direction of the line sensor. This ensures that even if there is a misalignment in the XY direction of the eye being examined, the indicator light beam, which is displaced in the Z direction, can still be incident on the line sensor.

[0106] Furthermore, in the above-described embodiment, the illumination control of light sources 56 and 41 was used to prevent the indicator 41I from light source 41 from being projected onto the eye under examination during the exposure time of image sensor 52, and to prevent the indicator 56I from being projected onto the eye under examination during the exposure time of image sensor 48. However, the embodiment is not limited to this. For example, mechanical or electronic shutters may be provided in the optical paths of the indicator projection of light source 41 and light source 56, respectively, and the opening and closing of each shutter may be controlled to prevent the projection of the noisy indicator 41I during the exposure time of image sensor 52, and to prevent the projection of the noisy indicator 56I during the exposure time of image sensor 48. Similarly, mechanical or electronic shutters may be provided in the illumination optical path of the anterior segment illumination unit 92. [Explanation of Symbols]

[0107] 1. Eye examination device 10 Objective measurement optical system 11 Light source 22 Imaging elements 29 Dichroic Mirror 40a 2nd target projection optical system 48 Image sensors 50 Observation Optical System 50A Alignment Detection Optical System 52 Image sensors 55 First indicator projection optical system 70 Control unit 80 Light guiding optical system 85 Concave mirror

Claims

1. An optometry device equipped with means for examining the eye to be examined, Alignment detection means for detecting the alignment state of the examination means with respect to the eye being examined, The device comprises control means for controlling the operation of the eye examination device, The alignment detection means is A first indicator projection means for projecting a first indicator onto the eye to be examined for aligning the examination means in at least one of the following directions: left / right, up / down, front / back, and rear; A first detector that detects the first indicator projected onto the eye under examination, A second indicator projection means for projecting a second indicator for aligning the examination means in a second direction that is different from the first direction, in at least one of the left / right, up / down, or front / back directions relative to the eye under examination, It comprises a second detector that detects the second indicator projected onto the eye under examination, The ophthalmic device is characterized in that the control means controls the exposure time of the first detector and the second detector to be shorter than the interval between their respective frames, and so that the timing of their respective exposure times does not overlap.

2. In the eye examination device of claim 1, The ophthalmography apparatus is characterized in that the control means controls the first indicator projection means and the second indicator projection means so that the second indicator is not projected onto the eye under examination within the exposure time of the first detector, and the first indicator is not projected onto the eye under examination within the exposure time of the second detector.

3. In the eye examination device of claim 1, The ophthalmic device is characterized in that the control means adjusts the relationship between the frame phases of the first detector and the second detector so that the timing of the exposure times of the first detector and the second detector do not overlap.

4. In the eye examination device of claim 1, The control means is characterized by controlling the total time of the exposure time of the first detector and the exposure time of the second detector within the frame interval so that it falls within the time interval of the frame interval.

5. In any ophthalmic device according to claim 1 to 4, The inspection means comprises an inspection optical system having an inspection light source that projects inspection light onto the eye to be examined, and an inspection light receiving element that receives the reflected light of the inspection light from the eye to be examined. The inspection optical system includes a first wavelength limiting means that limits the wavelength of the return light from the eye under examination of the first and second indicators used for alignment to be incident on the inspection light receiving element. The ophthalmic examination apparatus is characterized in that the alignment detection means comprises a second wavelength limiting means that limits the wavelength of the reflected light from the eye under examination to the first detector and the second detector.

6. In any ophthalmic device according to claim 1 to 4, The inspection means comprises an inspection optical system having an inspection light source that projects inspection light onto the eye to be examined, and an inspection light receiving element that receives the reflected light of the inspection light from the eye to be examined. The optometry device includes a light guiding optical system that guides indicator light of the first indicator and the second indicator to the eye under examination, and guides the reflected light of the indicator light from the eye under examination to the first detector and the second detector, and further includes a light guiding optical system that guides the inspection light from the inspection optical system to the eye under examination, and guides the reflected light of the inspection light from the eye under examination to the inspection optical system, An optometry device characterized in that alignment and examination are performed with the subject's eyes open using the aforementioned light-guiding optical system.

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