JP2014147416A - Subjective type eye refractivity measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subjective type eye refractivity measuring device capable of smoothly measuring eye refractivity without placing a correction optical system in front of a subject.SOLUTION: A subjective type eye refractivity measuring device comprises: a light-emitting optical system that emits a target light beam for forming an inspection target on a fundus of a subject's eye, to the subject's eye; a correction optical system that is arranged in a light path of the light-emitting optical system and can change refractivity; and a relay optical system that relays the light beam after passing through the correction optical system and is arranged so as to form an image of the correction optical system in front of the subject's eye, and the device measures eye refractivity of the subject's eye by changing the refractivity of the correction optical system. The device also comprises: distance changing means for optically making presented distance of the target different between at the time of distant vision inspection and at the time of near vision inspection; and light path switching means for switching between a first light path for emitting the target light beam to the subject's eye from a horizontal direction and a second light path for emitting the target light beam to the subject's eye from a direction inclined downward to the horizontal direction.

Description

  The present invention relates to a subjective eye refractive power measurement apparatus that presents a visual target to an eye to be examined.

  Conventionally, as a subjective eye refractive power measurement device, for example, a correction optical system capable of adjusting the refractive index is individually arranged in front of the subject's eye, and an inspection target is placed on the fundus of the subject's eye via the correction optical system. The one that projects light is known (see Patent Document 1). The examiner receives the response of the subject, adjusts the correction optical system until the target looks appropriate to the subject, obtains a correction value, and measures the refractive power of the eye based on the correction value .

JP-A-5-176893 JP 59-85642 A

  By the way, there is an apparatus configured so that an image of the correction optical system can be formed in front of the eye of the subject eye via the relay optical system without arranging the correction optical system in front of the subject's eye (Patent Document 2). reference).

  By the way, Patent Document 2 discloses a configuration for performing a near-field inspection by switching the presentation distance of a visual target to a near-distance. However, in Patent Document 2, the direction in which the visual target is presented does not change between the distance inspection and the near inspection.

  In view of the above problems, it is an object of the present invention to provide a subjective eye refractive power measuring apparatus that can smoothly measure eye refractive power without arranging a correction optical system in front of the subject's eyes.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

  A projecting optical system for projecting a target luminous flux for forming a test target on the fundus of the subject's eye toward the subject's eye, and a refractive power in the optical path of the projecting optical system may be changed. A correction optical system configured as described above, and a relay optical system arranged to relay a light beam that has passed through the correction optical system, and to form an image of the correction optical system in front of the eye of the subject eye, A subjective ocular refractive power measurement device for measuring the refractive power of the eye to be examined by changing the refractive power of the correction optical system, and presenting the optotype at a distance examination and a near examination Distance changing means for optically changing the distance; a first optical path for projecting the target luminous flux from the horizontal direction toward the eye to be examined; and the subject from a direction inclined downward with respect to the horizontal direction. Optical path switching for switching between the second optical path for projecting the target luminous flux toward the optometry Characterized in that it comprises a stage, a.

  According to the present invention, it is possible to present an appropriate visual target to a subject.

<First Embodiment>
FIG. 1 is an external view of an apparatus according to the first embodiment. FIG. 2 is a schematic configuration diagram showing the inside of the present embodiment. The apparatus of the present invention is generally composed of a target projection system 10, a correction optical system 20, a relay optical system 30, a detection optical system 40, and a deviation correction means 50. The target light projecting system 10 is a light projecting optical system that projects a test target on the eye E to be examined. The correction optical system 20 is configured to be able to change the refractive index of the light beam of the examination target toward the left and right eye E. The relay optical system 30 relays the visual target that has passed through the correction optical system 20 to the eye E to be examined. The detection optical system 40 is a displacement detection unit that detects a displacement of the eye E. The detection optical system 40 detects a positional shift of the eye E during measurement of eye refractive power. The deviation correction unit 50 is a correction unit that corrects the imaging position of the inspection target based on the deviation of the eye position. In addition, R and L attached | subjected to a code | symbol below shall respectively show the object for right eyes, and those for left eyes. In the following description, the positional relationship between the eye E and the device will be described with the front-rear direction in the state where the eye E and the device face each other as the Z direction, the left-right direction as the X direction, and the vertical direction as the Y direction.

<Appearance>
FIG. 1A is a schematic view of a subjective eye refractive power measurement apparatus (hereinafter abbreviated as “apparatus”) 1 according to the present embodiment viewed from an oblique direction. The apparatus 1 includes a housing 2, a presentation window 3 for presenting a visual target to the subject, a controller 4 for operating the apparatus 1, and a forehead for keeping the distance between the eye E and the apparatus 1 constant. A pad 60 is provided.

  FIG.1 (b) is a figure when the forehead pad 60 of this embodiment is seen from A direction. The forehead support 60 includes a contact portion 61, a connecting portion 62, a rotation knob 63, and a feed screw 64. The feed screw 64 is screwed with the female screw portion 65 of the connecting portion 62. Further, the feed screw 64 is engaged with the contact portion 61. The rotary knob 63 is provided at the end of the feed screw 64 on the apparatus 1 side. The connecting portion 62 has a groove 66. The contact portion 61 is provided with a convex portion 67. The groove 66 and the convex portion 67 prevent the contact portion 61 from rotating.

  Thus, when the examiner rotates the rotary knob 63, the contact portion 61 is pushed out or pulled back in the direction of the rotation axis of the feed screw 73. Therefore, the contact portion 61 can be moved in the Z direction by operating the rotary knob 63.

  Moreover, the optotype presenting apparatus 1 according to the present embodiment includes notification means 8. The notification means 8 notifies that the positions of the apparatus 1 and the eye E to be examined in the Z direction are appropriate. As the notification means 8, a light source, a speaker, etc. can be considered. Details of the notification means 8 will be described later.

  A target projection system 10, a correction optical system 20, a relay optical system 30, a detection optical system 40, a deviation correction means 50, and the like are disposed inside the housing 2.

<Target projecting system>
The target projection system 10 will be described with reference to FIG. The target light projecting system 10 includes, for example, a target light projecting unit 11, a half mirror 14, a concave mirror 15, a driving unit 16, and the like. The target light projecting unit 11 includes, for example, a light source 12, a liquid crystal display 13, and the like, and projects an inspection target.

  The liquid crystal display 13 has a structure in which, for example, a special liquid is sealed between two glass plates, the direction of liquid crystal molecules is changed by applying a voltage, and an image is displayed by increasing or decreasing light transmittance. . The emitted light from the light source 12 passes through the liquid crystal display 13 so that the displayed image can be projected.

  The target light projecting unit 11 can project various inspection targets for detection of spherical power, cylindrical power, cylindrical axis, and the like. These inspection targets are selected by, for example, the display on the display 13 being controlled by the control unit 90 and projected by the light source 12.

  The light beam on which the inspection target of the display 13 is projected passes through the half mirror 14 and is reflected by the concave mirror 15. Then, the reflected light beam is reflected by the half mirror 14. The reflected light beam enters the pair of correction optical systems 20R and 20L.

  The drive unit 16 allows the target light projecting unit 11 to move toward or away from the concave mirror 15. The drive unit 16 functions as a distance changing unit that optically changes the presentation distance of the target between the distance inspection and the near inspection.

<Correction optics>
The pair of correction optical systems 20R and 20L corrects the spherical power, the cylindrical power, the cylindrical axis, and the like. The correction optical system 20R is for right eye measurement, and the correction optical system 20L is for left eye measurement, and these have the same optical configuration. FIG. 3 is a schematic view of the correction optical systems 20R and 20L viewed from the direction B in FIG.

  As shown in FIG. 3, when the inspection optical paths of the correction optical systems 20R and 20L are the optical path L1 and the optical path L2, respectively, the distance D between the optical path L1 and the optical path L2 is set to the interpupillary distance of the subject.

  The correction optical systems 20R and 20L will be described by taking the correction optical system 20R as an example. A large number of optical elements (spherical lenses, cylindrical lenses, dispersion prisms, etc.) are arranged on the same circumference on the lens disk 21R provided in the correction optical system 20R. The lens disk 21R is rotationally controlled by the drive unit (actuator or the like) 22R, so that the optical element desired by the examiner is arranged in the right-eye inspection optical path L1.

  Further, the optical element (for example, a cylindrical lens, a cross cylinder lens, a rotary prism, or the like) disposed in the optical path L1 is rotationally controlled by the drive unit 23R, so that the optical element is rotated at the rotation angle desired by the examiner. Placed in. Switching of the optical elements arranged in the optical path L1 may be performed by operating input means (operation means) such as the controller 4.

  The lens disk 21R includes one lens disk or a plurality of lens disks as shown in FIG. When a plurality of lens disks are arranged, driving units 22aR to 22dR corresponding to the respective lens disks are provided. For example, as a lens disk group, each lens disk includes an opening (or a 0D lens) and a plurality of optical elements. Typical types of each lens disk are a spherical lens disk having a plurality of spherical lenses having different powers, a cylindrical lens disk having a plurality of cylindrical lenses having different powers, and an auxiliary lens disk having a plurality of types of auxiliary lenses. At least one of a red filter / green filter, a prism, a cross cylinder lens, a polarizing plate, a Madox lens, and an auto cross cylinder lens is disposed on the auxiliary lens disk. Further, the cylindrical lens may be arranged to be rotatable about the optical axis L1 by the driving unit 22aR, and the rotary prism and the cross cylinder lens may be arranged to be rotatable about each optical axis by the driving units 23bR and 23cR. .

  With the above configuration, the right-eye measurement correcting optical system 20R is configured to independently correct the refractive state such as the spherical power, the cylindrical degree, the cylindrical axis, and the prism value. Since the system 20L can be explained in the same manner, its details are omitted. The correction optical systems 20R and 20L may be configured such that the distance between the correction optical systems 20R and 20L can be adjusted so as to match the inter-pupil distance PD of the subject eyes ER and EL.

  In this case, a moving mechanism is provided for the lens disks 21R and 21L. The moving mechanism may move the lens disks 21R and 21L to adjust the relative distance between them. The interpupillary distance PD is measured by an interpupillary distance meter or the like, and the measurement result is input to the controller 4. Then, the control unit 90 drives the moving mechanism so that the distance D matches the inter-pupil distance PD, and moves the lens disks 21R and 21L. The pupillary distance measuring means may be provided in the apparatus 1.

<Relay optical system>
As shown in FIG. 2, the relay optical system 30 includes, for example, a half mirror 31, a concave mirror 32, a tracking mirror 33, a concave mirror 34, and a moving mechanism 35 that can move the tracking mirror 33 downward (Y direction). May be. The moving mechanism 35 includes a driving unit 36, and moves the tracking mirror 33 downward (Y direction).

  The moving mechanism 35 is an optical path switching unit that switches an optical path for projecting the target luminous flux toward the eye E. For example, the moving mechanism 35 projects the target light beam from the horizontal direction toward the subject eye E, and projects the target light beam onto the eye E from a direction inclined downward with respect to the horizontal direction. Switch to the second optical path. For example, the moving mechanism 35 changes the arrangement of the optical member (the tracking mirror 33 or the like) and switches the optical path of the target luminous flux.

  Each light beam that has passed through the pair of correction optical systems 20R and 20L passes through the half mirror 31, is reflected by the concave mirror 32, and is collected. The light beam is reflected by the half mirror 31 and passes through the tracking mirror 33. The light beam that has passed through the tracking mirror 33 is reflected by the concave mirror 34. Then, the reflected light is reflected by the tracking mirror 33, reaches the eyes ER and EL to be examined, and forms a target image on both fundus.

  The light beams that have passed through the correction optical systems 20R and 20L are relayed in common by the relay optical system 30, and the correction optical systems 20R and 20L are placed at the spectacle wearing positions (for example, about 12 mm from the apex of the cornea) of both eyes ER and EL. The image is formed. Therefore, the correction optical systems 20R and 20L are equivalent to being arranged in front of the eyes, and the subject can collimate the target image in a natural state via the tracking mirror 33.

  In this way, the subject responds to the examiner while directly looking at the target in the natural vision state, corrects the test target until the test target looks appropriate, and corrects the refractive index based on the correction value. Frequency measurement is to be performed.

<Detection optical system>
As shown in FIG. 2, the detection optical system 40 includes an automatic tracking light source 41, a shielding plate 42, a plane mirror 43, a half mirror 44, a condensing lens 45, a light receiving element 46, and the like. The detection optical system 40 detects a positional shift of the eye E during measurement of eye refractive power. Further, the detection optical system 40 detects a deviation between the eye E and the image of the correction optical system 20. For example, the light source 41 is attached to the test frame 7 so as to be disposed at the spectacle wearing position of the subject. Based on the positional deviation of the light source 41, the positional deviation of the eye E is detected. The shielding plate 42 has two holes 42a and 42b. The hole 42a and the hole 42b are provided at an interval. The lid 47 is provided to close the hole 42b. The drive unit 48 may be able to control the lid 47 to open and close the hole 42b.

  The light beam emitted from the light source 41 passes through the tracking mirror 33 and passes through holes 42 a and 42 b opened in the shielding plate 42. The light beam that has passed through the hole 42 a passes through the half mirror 44. Thereafter, the light beam is condensed by the condenser lens 45 and received by the light receiving element 46. On the other hand, the light beam that has passed through the hole 42 b is reflected by the flat mirror 43 and the half mirror 44. Then, the light is condensed by the condenser lens 45 and received by the light receiving element 46. As the light receiving element 46, a two-dimensional sensor such as a CCD, CMOS, or PSD (optical position sensor) may be used.

  A method for adjusting the working distance according to the present embodiment will be described. In the present apparatus 1, the working distance with respect to the eye E is set so that the two light beams that have passed through the holes 42a and 42b are matched and received by the light receiving element 46. That is, the position where the images of the correction optical systems 20R and 20L are formed coincides with the position of the lens frame of the test frame 7 (for example, in front of the subject by 12 mm from the apex of the cornea) in the Z direction (working distance direction). .

  Such a configuration is generally called a range finder and is used for focusing the camera. As a method of adjusting the working distance, for example, the examiner operates the rotary knob 63 to push the contact portion 61 to the subject side to the limit. The examiner causes the subject to wear the test frame 7. Then, an instruction is given to apply the forehead of the subject to the contact portion 61.

  At this time, light emitted from the light source 12 attached to the test frame 7 is separated by the holes 42a and 42b. The separated light beams pass through the condenser lens 45 and are condensed at different positions on the surface of the light receiving element 46.

  The examiner operates the rotary knob 63 and gradually pulls the contact portion 61 back toward the apparatus 1. At the same time, the forehead of the subject, the test frame 7 and the light source 41 are also moved in the direction of the apparatus 1. When the distance between the light source 41 and the device 1 is appropriate, the light beams separated by the holes 42a and 42b are focused on the surface of the light receiving element 46 and condensed.

  At this time, the control unit 90 detects from the signal of the light receiving element 46 that the working distance has become appropriate, and sends a command signal to the notification means 8. When receiving the command signal, the notification means 8 notifies the examiner that the distance in the Z direction between the test frame 7 and the apparatus 1 has become appropriate.

  When the notification means 8 is activated, the examiner recognizes that the working distance is appropriate. Then, the examiner finishes the operation of the rotary knob 63 and completes the working distance adjustment.

  In addition, not only a two-dimensional sensor but one-dimensional sensors, such as a line sensor, can be considered, for example. In this case, the two one-dimensional sensors may be arranged to form at least a certain angle (preferably 90 degrees). In addition, the light flux may be separated into two by using a separator lens or the like in order to focus the light flux on the two sensors.

<Deviation correction means>
The deviation correction means 50 is constituted by, for example, a tracking mirror 33 and a drive mechanism 51 (see FIG. 2). The tracking mirror 33 is disposed in the common optical path of the pair of left and right correction optical systems 20R and 20L. By rotating the tracking mirror 33, the positions where the images of the correction optical systems 20R and 20L (optical elements disposed in the optical paths L1 and L2 in the image) are formed are corrected.

  Note that the images of the correction optical systems 20R and 20L (optical elements disposed in the optical paths L1 and L2 in the image) are not images formed by actually collecting light. That is, the position where the images of the correction optical systems 20R and 20L are formed is a position conjugate with the correction optical systems 20R and 20L (optical elements disposed in the optical paths L1 and L2 in the relay optical system 30). .

  The tracking mirror 33 may be an optical member such as a light reflecting member. The drive mechanism 51 may be able to change the direction in which the mirror surface of the tracking mirror 33 faces. As the drive mechanism 51, for example, a horizontal mechanism and a vertical mechanism, or a rotation mechanism having either one of the rotation axes can be considered.

  The deviation correcting means 50 drives an optical member such as the tracking mirror 33 to form an image of the correction optical systems 20R and 20L (optical elements arranged in the optical paths L1 and L2), for example. To deflect. As a result, the position where the image of the correction optical system 20R, 20L (the optical element disposed in the optical path L1, L2) is formed is optically corrected so as to be positioned in front of the eye E. The front of the eye E is, for example, the spectacle wearing position of the eye E.

  The drive mechanism 51 may include a drive unit (for example, a boil coil motor mechanism) 52 and rotate the tracking mirror 33 with respect to a horizontal rotation axis and a vertical rotation axis. That is, the drive unit 52 may rotate the tracking mirror 33 in the XY directions. In addition, a configuration in which a plurality of reflection mirrors for correcting deviation (for example, a galvano motor mechanism is used) may be used. In this case, one is rotated in the X direction and the other is rotated in the Y direction. Also good.

<Control system>
FIG. 4 is a block diagram showing a control system of this embodiment. The controller 90 included in the controller 4 includes the light source 12 of the target projection system 10, the display 13, the drive unit 16, the drive units 22 and 23 of the correction optical system 20, the drive unit 36 of the relay optical system 30, and the detection optical system 40. May be connected to the light source 41, the light receiving element 46, the driving unit 48, the driving unit 52 of the deviation correcting means 50, the memory 80 of the controller, and the like. The control unit 90 receives a light reception signal from the light receiving element 46. The control unit 90 controls the drive unit 52 based on the received light signal, and controls the direction in which the tracking mirror 33 faces.

<Tracking mirror control method>
A method for controlling the tracking mirror 33 will be described. FIG. 5 shows an example of correcting the positional deviation of the eye E under examination in the apparatus according to the present embodiment. FIG. 5A is a state before the eye position of the eye E is shifted, FIG. 5B is a view immediately after the eye position is shifted in the Y direction, and FIG. 5C is a tracking based on the shift. This is a state after the angle of the mirror 33 is corrected. Note that the eye E and the light source 41 move together. Further, it is assumed that the hole 42b is closed by the lid 47 during the inspection.

  As shown in FIG. 5A, the light source 41 is at the reference position P, and the tracking mirror 33 is in the reference posture (for example, a position inclined by 0 ° in the X direction and 45 ° in the Y direction). In a state where the light source 41 is at the position P, an image of the correction optical system 20 is formed in front of the eye E. As a result, the target luminous flux incident on the eye E is imaged at an appropriate position with respect to the eye E. The light beam from the light source 41 emitted from the position P passes through the tracking mirror 33, the hole 42 a, the half mirror 44, and the condenser lens 45, and is condensed on the reference point O on the surface of the light receiving element 46. The light receiving element 46 transmits a light reception signal to the control unit 90. Then, the control unit 90 obtains position information of the reference point O based on the light reception signal. The memory 80 stores position information of the reference point O.

  From here, it is assumed that the light source 41 has moved to a position Q shifted by ΔY in the Y direction, as shown in FIG. In a state before the angle of the tracking mirror 33 is corrected, the image of the correction optical system 20 is formed at a position deviating from the front of the eye to be examined. As a result, the target luminous flux incident on the eye E is imaged at an inappropriate position with respect to the eye E. At this time, the light beam of the light source 41 emitted from the position Q passes through the tracking mirror 33, the hole 42 a, the half mirror 44, and the condenser lens 45, and is condensed at a point V 1 on the surface of the light receiving element 46. The point V1 is a position shifted from the reference point O by ΔY ′ in the Y direction. The light receiving element 46 transmits the light reception signal at this time to the control unit 90. The controller 90 detects the shift amount and the shift direction of the point V1 from the reference point O from the received light signal.

  The control unit 90 controls the drive unit 52 based on the light reception signal from the light receiving element 46. As an example of the control method, the control unit 90 may change the direction by driving the tracking mirror 33 by the drive amount stored in advance in the memory 80 based on the shift amount ΔY ′ and the shift direction. For example, the memory 80 stores an angle θ1 ° when the point V1 is shifted from the reference point O by ΔY′1, an angle θ2 ° when the point V1 is shifted by ΔY′2, and an angle θ3 when the point V1 is shifted by ΔY′3. The angle θ corresponding to the shift amount ΔY ′ is stored in advance, such as °,. The angle θ ° (rotation amount, rotation direction) corresponding to the deviation amount ΔY may be obtained by calculation or may be obtained by experiment. The control unit 90 obtains a deviation amount ΔY ′ from the light reception signal from the light receiving element 46 and rotates the tracking mirror 33 by an angle θ ° corresponding to ΔY ′ stored in the memory 80. Thereby, it correct | amends so that the image of the correction optical system 20 may be formed in front of the eye E to be examined. Accordingly, the target luminous flux incident on the eye E is imaged at an appropriate position. As described above, when the position of the eye E is shifted, the tracking mirror 33 is rotated to correct the position where the image of the correction optical system 20 is formed. Yes.

  The drive amount and drive direction of the tracking mirror 33 are determined based on the deviation of the point V1 from the reference point O, but may be determined based on the position information (address) of the point V1. Also by such a method, when the position of the eye E shifts, an appropriate visual target can be presented to the eye E.

  In the above description, the control method of the tracking mirror 33 in the case where a positional deviation in the Y direction has occurred has been described, but the description is omitted because the same control method is used when a positional deviation in the X direction occurs. To do.

<Distant inspection procedure / operation>
A procedure for performing a distance examination of the eye E using the apparatus 1 of the present embodiment will be described together with the operation of the apparatus 1. First, the examiner operates the controller 4 to set the measurement mode to the distance measurement mode. Then, a desired distance test target is presented on the presentation window 3. Next, the examiner causes the subject to wear the test frame 7. The examiner instructs the forehead 60 to apply the subject's forehead and observes the presentation window 3. The examiner adjusts the position of the forehead pad 60 in the working distance direction by operating the knob 63 until the notification means 8 is activated (for example, the lamp is lit). When the position adjustment of the forehead pad 60 is completed, the examiner closes the hole 42 b with the lid 47 by operating the controller 4. The control unit 90 controls the driving unit 48 to close the hole 42b with the lid 47. Thereby, the light beam received by the light receiving element 46 is only the light beam that has passed through the hole 42a. The light beam that has passed through the hole 42a is used to detect the eye position in the XY directions.

  Next, the eye position in the XY directions is detected. The light beam from the light source 41 that has passed through the hole 42a passes through the half mirror 44 and the condenser lens 45, and is condensed, for example, at a point G on the surface of the light receiving element 46 (see FIG. 6). The light receiving element 46 sends a light reception signal at this time to the control unit 90. The control unit 90 receives the light reception signal, and calculates a direction shifted from the reference point O by the shift amounts ΔX′g and ΔY′g of the point G.

  When the detection of the eye position in the XY direction is completed, the control unit 90 rotates the tracking mirror 33 from the memory 80 in the X direction based on the shift amounts ΔX′g and ΔY′g, the rotational direction, and the Y direction. The rotation angle θY ° and the rotation direction are respectively read out. The control unit 90 controls the drive unit 52 to change the direction in which the tracking mirror 33 faces. By changing the direction of the tracking mirror 33, the image of the correction optical system 20 is corrected so as to be formed in front of the eye E. Therefore, the target luminous flux incident on the eye E is imaged at an appropriate position with respect to the eye E.

  When the examination target can be appropriately presented to the eye E by the above operation, the examiner starts the distance examination. The examiner causes the subject to look directly at the visual target in the natural vision state and asks about the appearance of the inspection visual target. The examiner performs correction by the correction optical systems 20R and 20L until the inspection target looks appropriate, and measures the refractive power based on the correction value.

  By the way, during the examination, the posture of the subject may change, and the position of the eye E to be examined may shift. In this case, since the image forming position of the correction optical system 20 deviates from the front of the eye E, the subject cannot observe an appropriate inspection target. When the position of the eye E is shifted, the position of the light source 41 is also shifted. When the position of the light source 41 is shifted, the position where the light beam from the light source 41 is condensed on the surface of the light receiving element 46 is shifted.

  For example, the shifted position is point K. The light receiving element 46 sends the light reception signal at this time to the control unit 90. The control unit 90 receives the light reception signal, and calculates a direction shifted from the deviation amounts ΔX′k and ΔY′k of the point K from the reference point O. Based on the deviations ΔX′k and ΔY′k, the control unit 90 rotates the tracking mirror 33 from the memory 80 in the X direction with the angle θX ° and the rotation direction, and the angle θY ° with which the tracking mirror 33 is rotated in the Y direction. Read the direction of rotation. The control unit 90 controls the drive unit 52 to change the direction in which the tracking mirror 33 faces. By changing the direction of the tracking mirror 33, the image of the correction optical system 20 is corrected so as to be formed in front of the eye E. That is, the position shift of the eye E during the eye refractive power measurement is detected, and the image formation position is corrected so that the image of the correction optical system 20 is restored to the front of the eye E. Therefore, the target luminous flux incident on the eye E is imaged at an appropriate position with respect to the eye E.

  With the above-described configuration, even if the position of the eye E to be inspected is shifted during the examination and the image forming position of the correction optical system 20 is deviated from the front of the eye E, the image of the correction optical system 20 can be obtained. It can be formed again in front of the eyes. Thereby, an appropriate visual target can be presented to the eye E to be examined. Accordingly, the subject does not observe an inappropriate visual target due to the position of the eye E to be displaced. In addition, the subject does not need to maintain a constant posture during the examination, and can perform the examination with an easy posture. The examiner does not need to adjust the position of the apparatus or the subject after confirming the positional deviation of the eye E.

<Near-term inspection procedure / operation>
The procedure for performing the near-field inspection will be described together with the operation of the apparatus 1. FIG. 7 is a schematic view showing the arrangement of the optical system during the near-field inspection. The examiner operates the controller 4 to set the measurement mode to the near measurement mode. When the near measurement mode is set, the control unit 90 controls the driving unit 16 to bring the target light projecting unit 11 (for example, the light source 12 and the display 13) closer to the concave mirror 15. By changing the optical path length, the inspection target can be presented at a near distance (for example, 40 mm forward from the eye E). When the near distance is set to be short, it is conceivable that the half mirror 14 and the concave mirror 15 are replaced with a convex lens. In this configuration, when the inspection target is presented by switching from the distance to the near distance, the target light projecting unit 11 may be brought closer to the convex lens. For this configuration, refer to Japanese Patent Application Laid-Open No. 59-85642.

  Further, when the target light projecting unit 11 is moved, the frequencies of the correction optical systems 20R and 20L are changed. Therefore, the powers of the correction optical systems 20R and 20L may be corrected based on the distance moved by the target light projecting unit 11. For example, when the measurement mode is set to the near measurement mode, the control unit 90 inspects the state where the spherical lens having the refractive power of +10 diopter is arranged in the optical paths L1 and L2 as the 0 diopter state (uncorrected state). May be. Accordingly, both inspections can be performed using the same correction optical system 20 without replacing the correction optical system 20 between the distance inspection and the near inspection.

  Further, when the near measurement mode is set, the control unit 90 controls the drive unit 36 to move the position of the tracking mirror 33 downward (Y direction) with respect to the eye E. When the tracking mirror 33 is moved downward, the relay optical system 30 projects the target light beam onto the eye E from below in comparison with the distance examination. The subject inclines the line of sight downward from the horizontal direction in order to observe the inspection target.

  Subsequent inspection procedures and operation of the apparatus are the same as those during the distance inspection, and thus description thereof is omitted. However, when the tracking mirror 33 is moved downward (Y direction), it is conceivable that the refractive index of the light beam reaching the eye E changes due to the change in the length of the optical path. In this case, it is preferable to adjust the working distance of the forehead pad 60 again at the near-field inspection.

  Generally, when a person naturally views a nearby object, the line of sight tilts downward from the horizontal direction. As described above, the near-inspection of the subject can be performed in a state closer to natural vision by moving the tracking mirror 33 downward and tilting the visual line of the subject downward from the horizontal direction. .

  In the near-field examination, as described above, the detection optical system 40 and the deviation correction unit 50 can correct the image of the correction optical system 20 so as to be formed in front of the eye E to be examined.

  By the way, in the near-field inspection, for example, the subject may tilt the neck forward and tilt the line-of-sight direction downward. In such a case, it may be difficult to detect the eye E from a certain direction (for example, a horizontal direction with respect to the eye E). For example, this is a case where the eye E is hidden behind the eyelid.

  The detection optical system 40 of the present embodiment detects the light source 41 of the test frame 7 worn by the subject in order to detect the displacement of the eye E to be examined. The position of the test frame 7 can be detected even if a situation change occurs such as the subject's neck tilting. In this way, by detecting the position of the test frame 7 worn by the subject, it is possible to detect the positional shift of the eye E even when it is difficult to detect the eye E.

  Further, although the detection optical system 40 of the present embodiment detects the position of the test frame 7, it is not limited to this. For example, a characteristic part such as a nose or a mouth may be detected. Based on the detection result, it is only necessary to detect the displacement of the eye E or the like.

  As described above, the detection optical system 40 only needs to be able to obtain a shift between the eye position of the eye E and the eye position. Of course, as a technique for detecting the positional deviation of the eye E or the like, the positional deviation may be detected by directly detecting the position of the eye E.

  The target projection system 10 is not limited to the configuration of the present embodiment. For example, as shown in FIG. 8A, the target projection system 10 may include a light source 112, a display 113, a reflecting member 114, and a concave mirror 115. The light beam from the light source 112 projects the display on the display 113, is reflected by the reflecting member 114, and enters the concave mirror 115 obliquely. Then, the light beam is reflected by the concave mirror 115, travels on the optical axis of the concave mirror 115, and passes through the correction optical systems 20R and 20L. Since the optical path after that is the same as that of this embodiment, description is abbreviate | omitted.

  As described above, the half mirror 14 of the target projection system 10 can be omitted by providing a configuration in which the target luminous flux is incident on the concave mirror 115 from outside the optical axis of the concave mirror 115. Since the amount of light decreases each time the half mirror passes or reflects, the amount of the target luminous flux can be maintained by omitting this.

  As shown in FIG. 8B, the target projection system 10 may use a DMD (Digital Micromirror Device) 213 instead of the liquid crystal display 13. In general, DMD 213 has a high reflectance and is bright. Therefore, compared with the case where the liquid crystal display 13 using polarized light is used, the amount of the target luminous flux can be maintained.

  The detection optical system 40 is not limited to the configuration of this embodiment. For example, as shown in FIG. 9A, the detection optical system 40 may include two light sources 141a, 141b, a condenser lens 142, and a light receiving element 143 attached to the test frame 7. The positions at which the light beams of the light source 141a and the light source 141b are collected on the surface of the light receiving element 143 are different. For example, it is assumed that light is focused on point I and point J. The distance W between the points I and J varies depending on the distance between the light sources 141a and 141b and the device 1 in the Z direction (working distance direction).

  Therefore, the working distance of the forehead support 60 and the eye E can be adjusted so that the distance W between the two points becomes a preset distance. In such a configuration, the distance W increases when the eye E is close to the device 1, and the distance W decreases when the eye E is far from the device 1. Therefore, the control unit 90 may calculate the distance between the eye E and the apparatus 1 based on the length of the distance W. A drive unit may be provided for the control unit 90 to automatically adjust the position of the forehead pad 60 based on the calculated distance. Moreover, you may provide the alerting | reporting means for alert | reporting to an examiner that the distance of the to-be-tested eye E and the apparatus 1 is near or far.

  Detection of the position of the eye E in the XY directions can be considered in the same manner as in the present embodiment. For example, the position in the XY direction of the eye E can be detected based on the amount of deviation of the point I from a certain reference point and the direction of deviation.

  As described above, the detection optical system 40 only needs to be able to obtain the shift between the eye position of the eye E and the eye position.

  Further, the inclination of the test frame 7 may be detected from the positions of the points I and J. For example, as shown in FIG. 9B, the inclination α of two points may be detected, and the inclination of the test frame 7 may be detected based on the detection result. By detecting the inclination of the test frame 7, the inclinations of the left and right eyes EL and ER are detected. As described above, the detection optical system 40 functions as an inclination detection unit that detects the inclinations of the eyes ER and EL to be examined.

  When the left and right test eyes EL and ER are tilted, an image of the correction optical system 20 is formed at a position deviating from the front of the test eye E. Accordingly, when the detection optical system 40 detects the inclinations of the left and right eyes EL and ER, the control unit 90 activates the notification unit 8. Thereby, you may make it alert | report an examiner that the test | inspection target is not shown appropriately. The examiner confirms that the notification means 8 has been activated and instructs the subject not to tilt his / her neck sideways.

  Thus, the left and right eye to be examined EL. You may provide the detection means (for example, the alerting | reporting means 8) for alert | reporting the detection means (for example, the detection optical system 40) which detects the inclination of ER, and the result.

  The deviation correction unit 50 is not limited to the configuration of the present embodiment. For example, as shown in FIG. 10, the deviation correction means 50 may be configured to include the above-described configuration and a moving mechanism 151 that further moves the concave mirror 34. The moving mechanism 151 includes a drive unit 152 and the like.

  When the concave mirror 34 is moved in the XZ direction by the moving mechanism 151, the position where the image of the correction optical system 20 is formed changes. Accordingly, the control unit 90 controls the moving mechanism 151 based on the shift of the eye E detected by the detection optical system 40 and corrects the image of the correction optical system 20 to be formed in front of the eye E. In this way, an appropriate target presentation may be performed on the eye E to be examined.

  Further, as illustrated in FIG. 11, the deviation correction unit 50 may include the above-described configuration, and further include rotary prisms 233 a and 233 b and a moving mechanism 251. The moving mechanism 251 includes driving units 252a and 252b. The target luminous flux from the light source 12 that has passed through the correction optical systems 20R and 20L passes through the rotary optical system 30 and passes through the rotary prisms 233a and 233b and enters the eye E to be examined. When the rotary prisms 233a and 233b are rotated by the moving mechanism 251, the position where the image of the correction optical system 20 is formed changes. Thereby, you may correct | amend so that the image of the correction optical system 20 may be formed in front of the eye E to be examined. FIG. 11 illustrates the state before the rotary prism 233b is rotated by 90 ° (see FIG. 11A) and after the rotation (see FIG. 11B).

  As described above, the deviation correction unit 50 may change the optical path of the target light beam by the optical member. However, when the rotary prisms 233a and 233b are used, the light beams from the light source 41 may be affected by the rotary prisms 233a and 233b before reaching the light receiving element 46. Therefore, it is preferable that the detection optical system 40 be arranged at a position where the influence of the rotary prisms 233a, 233b, etc. does not reach. For example, the light receiving system such as the shielding plate 42, the flat mirror 43, the half mirror 44, the condensing lens 45, and the light receiving element 46 may be disposed above the half mirror 33 and closer to the subject than the concave mirror 34. Further, it may be disposed outside the housing 2.

  Further, as a modification example, it is conceivable to correct the position at which the image of the target luminous flux is formed based on the shift in the Z direction of the eye E during the examination. In this case, each of the correction optical systems 20R and 20L may be composed of a well-known Alvarez lens.

  The Alvarez lens is composed of two optical elements (for example, a phase difference plate) in which one surface is a special aspherical surface and the other surface is a flat surface. Then, the aspherical sides of these two optical elements are opposed to each other, kept at a position rotated by 180 °, and refracted by displacing (moving) them by the same displacement amount (movement amount) in opposite directions. The force can be changed continuously (US Pat. No. 3,305,294).

  The detection optical system 40 detects a shift of the eye E in the Z direction, and moves the target projection system 10 relative to the concave mirror 14 based on the detection result. At the same time, the two optical elements of the Alvarez lens may be displaced so as to correct the power change of the target luminous flux.

  Thus, during the examination, the position where the image of the correction optical system 20 is formed can be corrected based on the deviation of the eye E in the Z direction.

  In addition, although this apparatus 1 shall be provided with the control part 90 in the controller 4, it is not restricted to this. The control unit may be provided inside the housing 2. Alternatively, they may be provided inside the controller 4 and the housing 2, respectively. The control unit and each component connected thereto may be connected by wire or wireless.

It is an external appearance block diagram of the subjective eye refractive power measuring apparatus which concerns on this embodiment. It is the schematic which shows the optical system of the subjective eye refractive power measuring apparatus which concerns on this embodiment. It is the schematic of the correction optical system which concerns on this embodiment. It is a block diagram which shows the control system of the subjective eye refractive power measuring apparatus which concerns on this embodiment. It is a figure explaining the shift | offset | difference correction | amendment means of the subjective eye refractive power measuring apparatus which concerns on this embodiment. It is a figure which shows the change of the condensing position of the light receiving element shape of the subjective eye refractive power measuring apparatus which concerns on this embodiment. It is the schematic which shows arrangement | positioning of the optical system at the time of the near-field measurement of this embodiment. It is a figure for demonstrating the example of a change of this embodiment. It is a figure which shows the example of a change of a detection optical system. It is a figure which shows the example of a change of a deviation correction means. It is a figure which shows the example of a change of a deviation correction means.

DESCRIPTION OF SYMBOLS 1 Subjective eye refractive power measuring apparatus 2 Case 3 Presenting window 4 Controller 7 Test frame 10 Target light projection system 20 Correction optical system 30 Relay optical system 40 Detection optical system 50 Deviation correction means 60 Forehead

Claims (7)

A projecting optical system for projecting a target luminous flux for forming a test target on the fundus of the subject's eye toward the subject's eye, and a refractive power in the optical path of the projecting optical system may be changed. A correction optical system configured as described above, and a relay optical system arranged to relay a light beam that has passed through the correction optical system, and to form an image of the correction optical system in front of the eye of the subject eye, A subjective eye refractive power measurement device that measures the eye refractive power of the eye to be examined by changing the refractive power of the correction optical system,
A distance changing means for optically changing the presentation distance of the optotype at the distance inspection and at the near inspection;
A first optical path for projecting the target luminous flux from the horizontal direction toward the eye to be examined, and the target luminous flux are projected toward the subject eye from a direction inclined downward with respect to the horizontal direction. A subjective eye refracting power measuring device comprising: an optical path switching means for switching between the second optical path and the second optical path.   The optical path switching means is a driving means for driving an optical member arranged between the correction optical system and the subject to the correction optical system in order to switch the first optical path and the second optical path. The subjective eye refractive power measuring device according to claim 1. The optical member is a reflecting member for reflecting the target luminous flux toward the eye to be examined,
The subjective eye refracting power measuring apparatus according to claim 2, wherein the driving unit moves the reflecting member downward in order to switch the first optical path and the second optical path.   The awareness according to claim 1, further comprising a control unit that changes a power setting in the correction optical system with respect to a distance test when performing a near vision test by changing the presentation distance of the target by the distance changing unit. Type eye refractive power measuring device.   The subjective eye refractive power measurement apparatus according to claim 1, further comprising a displacement detection unit that detects a displacement of an image of the correction optical system with respect to the eye to be examined.   The deviation detecting means detects the positional deviation by detecting at least one of a characteristic part of a subject image other than the subject eye or a frame worn by the subject at least during the near-field examination. The subjective eye refractive power measuring device according to claim 5.   The optical path switching means switches between the first optical path and the second optical path in conjunction with the change of the presentation distance by the distance changing means. Eye refractive power measurement device.

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