JP2019177044A - Visual target presentation device - Google Patents

Abstract

To provide a visual target presentation device that can accurately perform an eye examination and can easily perform an alignment operation of an optical system.SOLUTION: A visual target presentation device 2 comprises: a housing 3; an eye chart 41 provided inside the housing 3; a visual target presentation optical system 5 provided inside the housing 3, and for presenting a luminous flux emitted from the eye chart 41 to a subject's eye E via an optical system arranged inside the housing 3; and a photographing part 6 for photographing the subject's eye E.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optotype presenting apparatus that presents an optotype attached to an eye chart for optometry toward an eye to be examined.

  In Patent Document 1 and Patent Document 2, position detection means for detecting the position of the eye to be examined, and driving for driving the light guide optical system so as to guide the target luminous flux to the eye to be examined based on the detection result of the position detection means. And a visual acuity testing device having the means. In the visual acuity test apparatuses described in Patent Literature 1 and Patent Literature 2, the position detection means includes a light emitting unit of a remote controller disposed on the subject side as a light projection means for projecting a detection light beam, And a position detecting element as an optical position detecting means for detecting the detection light beam projected from the remote controller.

  When the position detection means of the visual acuity test apparatus described in Patent Document 1 and Patent Document 2 detects the position of the eye to be examined, the examinee or the examiner uses the light emitting part of the remote control of the eye to be examined such as the eye height position. It is necessary to project the light beam for detection from the light emitting part of the remote controller. However, the position of the light-emitting part of the remote controller placed at the position of the eye to be examined by the subject or the examiner may change during the visual acuity test. If the position of the light emitting part of the remote control changes during the visual acuity test, there is a problem that an accurate test cannot be performed. Further, there is a problem that the operation of arranging the light emitting unit of the remote control at the position of the eye to be examined such as the eye height position and projecting the detection light beam from the light emitting unit of the remote control is complicated.

Japanese Patent Laid-Open No. 7-236612 JP-A-8-206064

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an optotype presenting apparatus that can perform an accurate optometry and can easily perform an alignment operation of an optical system. To do.

  According to the present invention, the subject is an optotype presenting apparatus that presents an optotype attached to an eye chart for optometry toward an eye to be examined. The optotype presenting apparatus is provided inside a housing and the housing. A visual chart, and a visual target presenting optical system that presents a light beam emitted from the visual chart provided in the interior of the housing to the eye to be examined through an optical system disposed in the interior of the housing; This is solved by an optotype presenting apparatus comprising an imaging unit that images the eye to be examined.

  According to the said structure, since an imaging | photography part image | photographs a to-be-examined eye, based on the image of the to-be-examined eye image | photographed by the imaging | photography part, the alignment of an optotype presentation optical system can be adjusted. Thereby, even if it is a case where the position of a to-be-examined eye changes by the position of a subject's neck and face changing, an exact optometry can be performed. In addition, a special instrument for projecting the position detecting light beam is not necessary. Thereby, based on the image of the eye to be examined photographed by the photographing unit, the alignment operation of the optotype presenting optical system can be easily performed.

  Preferably, the position of the eye to be examined is identified by analyzing an image of the eye to be examined photographed by the photographing unit, and the alignment operation of the optotype presenting optical system is controlled based on the position of the eye to be examined. It further has a control device to be executed.

  According to the above configuration, the control device identifies the position of the eye to be examined by analyzing the image of the eye to be examined photographed by the photographing unit, and controls the alignment operation of the optotype presenting optical system based on the position of the eye to be examined. Execute. Therefore, even when the position of the subject's eye changes due to the change in the position of the subject's neck or face, the control device controls the alignment operation of the optotype presenting optical system based on the position of the subject's eye. By executing this, the position of the optotype presenting optical system can be made to follow the change in the position of the eye to be examined. That is, the control device can execute tracking of the visual target presenting optical system with respect to the movement of the eye to be examined. As a result, an accurate optometry can be performed even when the position of the eye to be examined is changed by changing the position of the subject's neck or face by providing a visual table inside the housing.

  Further, when the control device specifies the position of the eye to be examined, the subject or the examiner does not have to project the position detection light beam from the position of the eye to be examined such as the eye height position. Therefore, it is possible to suppress the necessity of performing a complicated operation when the control device specifies the position of the eye to be examined.

  Preferably, the optotype presenting optical system has a reflecting member that reflects the luminous flux emitted from the visual table and presents it to the eye to be examined, and at least one of a horizontal axis and a vertical axis. A reflection member drive unit that rotates the reflection member, and the control device analyzes the image of the eye to be examined to determine the position of the eye to be examined in at least one of the horizontal direction and the vertical direction. By identifying and controlling the reflecting member driving unit based on the position of the eye to be examined, the light beam emitted from the visual table is reflected by the reflecting member toward the eye to be examined. .

  According to the configuration, the control device specifies the position of the eye to be examined in at least one of the horizontal direction and the vertical direction. Then, the control device controls the reflecting member driving unit based on the position of the eye to be examined, and reflects the light beam emitted from the visual table toward the eye to be examined by the reflecting member. Therefore, the control device can cause the position of the optotype presenting optical system to follow the change in the position of the eye to be examined in at least one of the horizontal direction and the vertical direction.

  Preferably, the imaging unit is arranged closer to the visual surface than the reflecting member with respect to the eye to be examined, and is configured to be able to image the eye to be examined via the reflecting member.

  According to the configuration, the photographing unit can be arranged inside the housing. Thereby, the imaging distance between the imaging unit and the eye to be examined can be shortened, and the space required for the optometry can be saved.

  Preferably, the camera further includes a near vision table driving unit that moves along the optical axis of the near vision table and the target presentation optical system in the interior of the housing, and the imaging unit is substantially from different directions. A first camera and a second camera for photographing the eye to be examined simultaneously, and the control device analyzes the plurality of images photographed substantially simultaneously by the first camera and the second camera. By identifying the position of the eye to be examined in the direction of the optical axis, and controlling the near vision table drive unit based on the position of the eye to be examined, between the near vision table and the eye to be examined The distance is adjusted to a predetermined presentation distance.

  According to the above configuration, the control device analyzes the plurality of images photographed substantially simultaneously by the first camera and the second camera, thereby determining the position of the eye to be examined in the direction of the optical axis of the optotype presenting optical system. Identify. And a control apparatus adjusts the distance between a near vision table and a to-be-tested eye to a predetermined | prescribed presentation distance by controlling a near vision table drive part based on the position of a to-be-examined eye. Therefore, the control device can cause the position of the near vision table to follow the change in the position of the eye to be examined in the direction of the optical axis of the optotype presenting optical system.

  Preferably, the apparatus further includes a display unit that displays an image of the eye to be examined photographed by the photographing unit.

  According to the said structure, the image of the eye to be examined image | photographed by the imaging | photography part is displayed on a display part. Therefore, even if the examiner cannot observe the subject's face and eye from between the eye to be examined and the front surface of the housing due to the short distance between the eye to be examined and the housing, the display unit By confirming the image displayed on the screen, the face and eye of the subject can be observed.

  Preferably, an infrared illumination that irradiates infrared rays toward the eye to be examined is further provided, and the imaging unit is an infrared camera having sensitivity to the infrared rays emitted from the eye to be examined.

  According to the said structure, the control apparatus can pinpoint the position of a to-be-tested eye by analyzing the image of the to-be-tested eye image | photographed with the infrared camera, without making a subject conscious of illumination. Further, even when the optotype presenting apparatus is installed in a relatively dark place such as a dark room, the control apparatus identifies the position of the eye to be examined by analyzing the image of the eye to be examined photographed by the infrared camera. be able to.

  According to the present invention, it is possible to provide an optotype presenting apparatus capable of performing an accurate optometry and easily performing an alignment operation of an optical system.

It is a perspective view showing the optotype presenting apparatus concerning the embodiment of the present invention. It is a side view showing the optotype presenting apparatus concerning this embodiment. It is a top view showing the optotype presenting apparatus concerning this embodiment. It is a block diagram showing the principal part structure of the optotype presenting apparatus concerning this embodiment. It is a flowchart showing the operation example of the optotype presenting apparatus which concerns on this embodiment. It is a flowchart showing the 1st specific example of a process of step S16 represented to FIG. It is a flowchart showing the 2nd specific example of a process of step S16 represented to FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments. Moreover, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.

FIG. 1 is a perspective view showing an optotype presenting apparatus according to an embodiment of the present invention.
FIG. 2 is a side view showing the optotype presenting apparatus according to the present embodiment.
FIG. 3 is a top view illustrating the optotype presenting apparatus according to the present embodiment.
FIG. 4 is a block diagram illustrating a main configuration of the optotype presenting apparatus according to the present embodiment.
2 and 3, for convenience of explanation, the housing of the optotype presenting apparatus is represented by a broken line.

  The optotype presenting apparatus 2 according to the present embodiment is an apparatus that presents an optotype attached to an eye chart for optometry toward the eye E to be examined, and includes a housing 3, a far-field chart 41, an optotype A presentation optical system 5 and a photographing unit 6 are provided. The optotype presenting apparatus 2 may further include an optometry table 9 and a control device 7. The optotype presenting optical system 5, the photographing unit 6, the control device 7, and the distance visual table 41 are provided inside the housing 3. Furthermore, a near vision table 42 may be provided inside the housing 3. In the present embodiment, a case where the near vision table 42 is provided inside the housing 3 will be described as an example.

  As shown in FIG. 1, the optometry table 9 includes a column 91, a subjective optometry means (refractor head) 92, and an illumination unit 93. The support column 91 is provided to be rotatable about an axis in the vertical direction Y. The subjective optometry means 92 and the illumination unit 93 are supported by the support column 91. The subjective optometry means 92 may be fixed to the housing 3 of the optotype presenting apparatus 2 and configured to be detachable with respect to the front surface of the eye to be examined.

  The housing 3 accommodates the near vision 42, the distance vision 41, the optotype presenting optical system 5, the imaging unit 6, and the control device 7, and faces the subject J. A window W is provided at the position. The window W is formed of a translucent resin such as polyacrylate resin (PMMA) and has a thickness of about 2 mm. In the optotype presenting apparatus 2 according to the present embodiment, since the near vision table 42 is provided inside the housing 3, the corneal apex of the eye E of the subject J, the front surface of the housing 3, The distance (working distance) WD between the two can be set to be less than the near optometry distance. Details of this will be described later. In the optotype presenting apparatus 2 according to the present embodiment, the front surface of the window W is an example of the front surface of the housing 3.

  The near vision table 42 is a near vision examination table, and presents a visual target to the eye E to be examined. For example, the near vision table 42 is disposed inside the housing 3 as an electronic display device such as a liquid crystal display device, and can display a visual target such as a Landolt ring on the display screen 421. However, the near vision table 42 is not limited to the liquid crystal display device, but may be another display device or a pattern drawn on paper or a glass plate.

  The distance visual chart 41 is a distance visual chart, and presents a visual target to the eye E to be examined. For example, the distance visual table 41 is disposed inside the housing 3 as an electronic display device such as a liquid crystal display device, and can display a visual target such as a Landolt ring on the display screen 411. However, the distance vision table 41 is not limited to the liquid crystal display device, and may be another display device or a pattern drawn on a glass plate or the like.

  The optotype presenting optical system 5 is provided inside the housing 3, and the light beam emitted from the distance visual table 41 and the near visual table 42 passes through the optical system disposed inside the housing 3 to be examined. Present to E. The optotype presenting optical system 5 includes a first reflection mirror 51, a convex lens system 52, and a second reflection mirror 53. The first reflecting mirror 51 reflects the light beam radiated from the distance visual table 41 toward the convex lens system 52. The convex lens system 52 refracts the light beam reflected by the first reflecting mirror 51 to form a virtual image. The display screen 411 of the far vision table 41 is disposed between the convex lens system 52 and the focal point 521 of the convex lens system 52. Further, the convex lens system 52 is not limited to one plano-convex lens shown in FIG. 2, and may have a plurality of lenses.

  When the distance examination is performed, the second reflection mirror 53 reflects the light beam transmitted through the convex lens system 52 toward the eye E to be examined, and the far-presentation position at a predetermined distance in front of the corneal apex of the eye E to be examined. A virtual image is presented at 531. At this time, for example, the near vision table 42 moves in response to the driving force transmitted from the near vision table drive unit 43 (see FIG. 4), and the outside of the optical path of the light beam emitted from the far vision table 41. Has been evacuated. The distance between the corneal apex of the eye E and the distance presentation position 531 is about 5 m.

  When the near examination is performed, the second reflection mirror 53 reflects the light beam emitted from the near vision table 42 and presents it to the eye E to be examined. The second reflecting mirror 53 of this embodiment is an example of the “reflecting member” in the present invention. As shown in FIG. 2, the near vision table 42 is provided on the light exit side of the convex lens system 52. Therefore, the light beam radiated from the near vision table 42 is not reflected by the first reflecting mirror 51 or transmitted through the convex lens system 52. However, the configuration of the visual target presenting optical system 5 of the present embodiment is an example, and is not limited to this.

  The imaging unit 6 is provided inside the housing 3 and images the eye E to be examined. The imaging unit 6 is arranged closer to the distance visual table 41 and the near visual table 42 than the second reflection mirror 53 with respect to the eye E, and can image the eye E via the second reflection mirror 53. It is configured. The imaging unit 6 includes a first camera 61 and can capture a two-dimensional image of the eye E. The two-dimensional image may be a moving image or a still image. The two-dimensional image may be a color image or a monochrome image. The imaging unit 6 may have two or more cameras. When the imaging unit 6 has two or more cameras, the first camera 61 and the second camera 62 image the eye E substantially simultaneously from different directions. In the present embodiment, a case where the photographing unit 6 includes the first camera 61 and the second camera 62 will be described as an example.

  The first camera 61 and the second camera 62 may be infrared cameras having sensitivity to infrared rays. When the first camera 61 and the second camera 62 are infrared cameras, the imaging unit 6 illuminates the eye E with infrared rays from the infrared illumination 64 provided in the housing 3 and is reflected by the eye E. An image of the eye E is taken with the infrared rays. According to this, the imaging unit 6 can capture an image of the eye E without making the subject J aware of the illumination. The infrared illumination 64 may be attached to the surface of the subjective optometry means 92 that faces the eye E to be examined.

  As illustrated in FIG. 4, the control device 7 includes a calculation unit 71, a storage unit 72, and an image processing unit 73. The calculation unit 71 is, for example, a CPU (Central Processing Unit) and the like, and executes program activation, signal control processing, calculation, drive control of each drive unit, and the like. That is, the calculation unit 71 performs overall control of the optotype presenting apparatus 2. The storage unit 72 stores, for example, a sequence program for alignment operation of the visual target presenting optical system 5, a sequence program for image processing, an arithmetic program, and the like. As the memory | storage part 72, the semiconductor memory etc. which were incorporated in the housing | casing 3 are mentioned, for example. Alternatively, the storage unit 72 may be a CD (Compact Disc), a DVD (Digital Versatile Disc), a RAM (Random access memory), a ROM (Read only memory), a hard disk, a memory card, or the like that can be connected to the target presentation device 2. Various storage media are listed.

  The image processing unit 73 includes an image analysis unit 74 and an image determination unit 731, and executes various image processing and image analysis on the image captured by the imaging unit 6. The image analysis unit 74 includes a feature point specifying unit 741 and a feature point position calculating unit 742, and specifies the position of the eye E by analyzing the image of the eye E taken by the photographing unit 6. . The “position of the eye E” refers to the position of the eye E in the horizontal direction X (see FIG. 1), the position of the eye E in the vertical direction Y (see FIG. 1), and the second reflection mirror 53 to be reflected. It includes at least one of the positions of the eye E in the direction (optical axis direction Z) of the optical axis LA2 (see FIG. 2) of the light beam guided to the eye E.

  The feature point identifying unit 741 identifies the position corresponding to the feature point E0 of the subject eye E in the image of the subject eye E by analyzing the image of the subject eye E photographed by the photographing unit 6. As described above, examples of the feature point E0 of the eye E include the corneal apex, the pupil center, the pupil contour, the iris center, and the iris contour. Specifically, the feature point specifying unit 741 corresponds to the feature point E0 in the image of the eye E based on the distribution of pixel values including the luminance value of the image of the eye E taken by the photographing unit 6. Specify the position to perform.

  The feature point position calculation unit 742 calculates the position of the corneal vertex of the eye E based on the position corresponding to the feature point E0 of the eye E specified by the feature point specification unit 741. For the position of the corneal apex of the eye E in the horizontal direction X and the vertical direction Y, the feature point position calculation unit 742 has a feature point E0 in the image taken by at least one of the first camera 61 and the second camera 62. It can be calculated as substantially matching the position corresponding to (for example, the pupil center). For the position of the corneal apex of the eye E in the optical axis direction Z, the feature point position calculation unit 742 includes the positions of the first camera 61 and the second camera 62 and the eye to be examined specified by the feature point specification unit 741. E is calculated based on a position (for example, pupil position) corresponding to the feature point E0 in the plurality of images. That is, the feature point position calculation unit 742 performs the first camera 61 and the second camera 62 with respect to the positions of the first camera 61 and the second camera 62 and the positions corresponding to the pupils in the plurality of images of the eye E. Calculation is performed by applying a known trigonometric method considering the arrangement relationship of the camera 62, and a position shifted by a certain amount is set as a corneal apex.

  Whether the image of the eye E is included in a predetermined region in the two-dimensional image captured by the imaging unit 6 by analyzing the image of the eye E captured by the imaging unit 6. Determine whether or not. The predetermined area is set in advance within the shooting range by the shooting unit 6, and is set as an area including the center of the shooting range, for example. The range of the predetermined area can be changed according to shooting conditions such as the position of the shooting unit 6 and the shooting magnification. The image determination unit 731 compares the coordinates corresponding to the predetermined area with the coordinates of the position corresponding to the feature point E0 of the eye E specified by the feature point specifying unit 741, thereby making the feature point of the eye E to be examined. It is determined whether or not a position corresponding to E0 is included in the predetermined area.

  As shown in FIG. 4, the imaging drive unit 63, the second reflection mirror drive unit 54, and the near vision table drive unit 43 are further provided inside the housing 3. The imaging drive unit 63 changes the positions and angles of the first camera 61 and the second camera 62 based on the signal transmitted from the control device 7. Based on the signal transmitted from the control device 7, the second reflecting mirror driving unit 54 rotates the second reflecting mirror 53 around the horizontal direction X axis or performs the second reflection around the vertical Y axis. The mirror 53 is rotated. That is, the second reflection mirror driving unit 54 changes the inclination angle of the reflection surface of the second reflection mirror 53 with respect to the horizontal plane, or changes the inclination angle of the reflection surface of the second reflection mirror 53 with respect to the vertical surface. The second reflecting mirror driving unit 54 of this embodiment is an example of the “reflecting member driving unit” in the present invention. The near vision table drive unit 43 moves the near vision table 42 along the direction of the optical axis LA1 (see FIG. 2) of the light beam emitted from the near vision table 42 and guided to the second reflecting mirror 53. For example, each of the imaging drive unit 63, the second reflection mirror drive unit 54, and the near vision table drive unit 43 includes an actuator such as a motor and a transmission member such as a gear and a belt.

  As shown in FIG. 4, the optotype presenting apparatus 2 according to the present embodiment may further include a user interface 8. The user interface 8 includes an operation unit 81, a display unit 82, and a notification unit 83. The operation unit 81 includes various buttons and keys provided outside the housing 3 and transmits signals related to the contents operated on the various buttons and keys to the control device 7. The display unit 82 includes a liquid crystal display device or the like, and can display an image of the eye E taken by the imaging unit 6. The operation unit 81 and the display unit 82 may not be provided as separate devices, and may be a device in which an operation function and a display function are integrated, such as a touch panel. The notification unit 83 performs notification by sound or light based on the signal transmitted from the control device 7. Examples of the notification unit 83 include a speaker and a light emitting diode (LED).

  Here, when the alignment operation of the optical system is performed, it is necessary to arrange a special instrument or the like for the subject or the examiner to project a light beam for position detection at the position of the eye to be examined such as the eye height position. If there is, there is a possibility that the position of the light emitting unit arranged at the position of the eye to be examined by the examinee or the examiner may change during the visual acuity examination. If the position of the light emitting unit changes during the visual acuity test, an accurate test cannot be performed. Further, the operation of arranging the light emitting unit at the position of the eye to be examined such as the eye height position and projecting the position detecting light beam from the light emitting unit is complicated.

  In addition, when the near vision is provided on the optotype presenting device, the distance between the eye to be examined and the front surface of the housing can be set shorter, and the trial frame or actual frame can be used without using the refractor head. This makes it possible to perform near-field inspections while wearing the glasses. On the other hand, a change in the position of the eye to be examined changes the distance from the eye to the visual table, the so-called optometry distance, which may affect the optometry accuracy. That is, in the distance test, since the presentation distance of the target is as long as about 5 m, the ratio of the change in the position of the eye to be examined with respect to the presentation distance is relatively low. Therefore, even if the position of the subject's eye changes due to the change in the position of the subject's neck or face, the optometry accuracy is hardly affected. On the other hand, in the near-field examination, the target distance of the target is about 30 cm or more and about 50 cm or less, so the ratio of the change in the position of the eye to be examined with respect to the presentation distance is relatively high. Therefore, when taking a near-field test, if the position of the subject's eye changes due to changes in the position of the subject's neck or face, an accurate test may not be performed.

  On the other hand, the optotype presenting apparatus 2 according to the present embodiment includes an imaging unit 6 that images the eye to be examined. According to this, since the imaging unit 6 captures the eye E, the alignment of the optotype presenting optical system 5 can be adjusted based on the image of the eye E captured by the imaging unit 6. Thereby, even if it is a case where the position of the eye E to be examined changes due to the change in the position of the neck or face of the subject E, accurate optometry can be performed. In addition, a special instrument for projecting the position detecting light beam is not necessary. Thereby, based on the image of the eye E to be examined photographed by the photographing unit 6, the alignment operation of the optotype presenting optical system 5 can be easily performed.

  Further, in the optotype presenting apparatus 2 according to the present embodiment, the control device 7 identifies the position of the eye E by analyzing the image of the eye E taken by the photographing unit 6, and the position of the eye E to be examined. Based on the above, control of the alignment operation of at least one of the near vision 42 and the target presentation optical system 5 is executed. In the specification of the present application, the “alignment operation” refers to an operation of performing alignment (alignment) of at least one of the near vision table 42 and the target presentation optical system 5 with respect to the position of the eye E.

  According to the optotype presenting apparatus 2 according to the present embodiment, even if the position of the eye E changes due to the change in the position of the neck or face of the subject J, the control device 7 can control the eye to be examined. By executing control of the alignment operation of at least one of the near vision 42 and the target presentation optical system 5 based on the position of E, at least one of the near vision 42 and the target presentation optical system 5 The position can be made to follow the change in the position of the eye E. That is, the control device 7 can execute the tracking of the near vision table 42 and the optotype presenting optical system 5 with respect to the movement of the eye E. As a result, the near vision 42 is provided inside the housing 3, and even if the position of the eye E changes due to the change in the position of the neck or face of the subject J, an accurate Can be inspected.

  Further, since the near vision table 42 is provided inside the housing 3, it is not presented between the eye E to be examined and the front surface of the housing 3 during the near vision examination. Therefore, it is not necessary to secure a space for presenting the near vision table 42 between the eye E and the front surface of the housing 3. Thereby, the distance WD between the eye E to be examined and the front surface of the housing 3 can be shortened, and the space L0 (see FIG. 2) necessary for optometry can be shortened and the space can be saved. Further, since the image analysis unit 74 identifies the position of the eye E by analyzing the image of the eye E taken by the photographing unit 6, the examiner and the subject J specify the position of the eye E. There is no need to take any special action to do this. For this reason, when the control device 7 specifies the position of the eye E, it is possible to suppress the necessity of performing a complicated operation.

  The imaging unit 6 is arranged on the far visual table 41 and the near visual table 42 with respect to the eye E with respect to the eye E, and images the eye E via the second reflective mirror 53. It is configured to be possible. According to this, the photographing unit 6 can be arranged inside the housing 3. Thereby, the imaging distance between the imaging | photography part 3 and the eye E to be examined can be shortened, the space L0 required for optometry can be shortened, and space saving can be carried out.

  In addition, when the near-inspection and the far-inspection are performed, the display unit 82 displays an image of the eye E to be inspected captured by the imaging unit 6. Specifically, the control device 7 executes control for causing the display unit 82 to display an image of the eye E to be examined, which has been photographed by the photographing unit 6. According to this, the examiner observes the face of the subject J and the eye E from between the eye E and the front surface of the housing 3 because the distance between the eye E and the housing 3 is short. Even if it is not possible, the face of the subject J and the eye E can be observed by confirming the image displayed on the display unit 82.

  Further, when the first camera 61 and the second camera 62 are infrared cameras, the image analysis unit 74 does not make the subject J aware of the illumination, and the eye E of the eye E photographed by the infrared camera. The position of the eye E can be specified by analyzing the image. Further, even when the optotype presenting apparatus 2 is installed in a relatively dark place such as a dark room, the image analysis unit 74 analyzes the image of the eye E taken by the infrared camera, thereby causing the eye E to be examined. Can be specified.

Next, an operation example of the optotype presenting apparatus according to the present embodiment will be described with reference to the drawings.
FIG. 5 is a flowchart showing an operation example of the optotype presenting apparatus according to the present embodiment.
FIG. 6 is a flowchart showing a first specific example of the process of step S16 shown in FIG.
FIG. 7 is a flowchart showing a second specific example of the process of step S16 shown in FIG.

  First, in step S <b> 11, when the optometry is started, the control device 7 starts photographing the eye E with the first camera 61 and the second camera 62. In the operation example of the flowchart shown in FIG. 5, the photographing of the eye E is moving image photographing. The first camera 61 and the second camera 62 perform moving image shooting at a predetermined frame rate. The shooting timings of the first camera 61 and the second camera 62 may be synchronized by the control device 7. The first camera 61 and the second camera 62 sequentially transmit the acquired frames to the control device 7. The control device 7 associates the frames transmitted from the first camera 61 and the second camera 62 according to the shooting timing. That is, the control device 7 associates the frames acquired substantially simultaneously by the first camera 61 and the second camera 62. This association is executed based on the input timing of the frames transmitted from the first camera 61 and the second camera 62, for example.

  Subsequently, in step S12, the feature point specifying unit 741 of the image analysis unit 74 analyzes each frame transmitted from the first camera 61 and the second camera 62, and thereby the feature point of the eye E to be examined in each frame. A process for specifying a position corresponding to E0 is executed. Note that before the feature point specifying unit 741 executes the process of specifying the position corresponding to the feature point E0 of the eye E, a process of correcting the distortion of each frame may be executed.

  Subsequently, in step S13, the control device 7 determines whether or not the feature point specifying unit 741 has succeeded in specifying a position corresponding to the feature point E0 of the eye E. When the feature point specifying unit 741 fails to specify the position corresponding to the feature point E0 of the eye E (step S13: NO), the control device 7 asks the examiner the face of the subject J (the subject An instruction is made to arrange the optometry) within a prescribed range (step S14). Based on this, the examiner adjusts the position and height of the subject J's chair and the visual table presentation device 2. And the feature point specific | specification part 741 performs the process mentioned above regarding step S12.

  On the other hand, when the feature point specifying unit 741 succeeds in specifying the position corresponding to the feature point E0 of the eye E (step S13: YES), the image determination unit 731 corresponds to the eye E in step S15. It is determined whether the image to be included is included in a predetermined area of the frame. When the image corresponding to the eye E is not included in the predetermined area of the frame (step S15: NO), the control device 7 executes the process described above with respect to step S14. On the other hand, when an image corresponding to the eye E is included in a predetermined area of the frame (step S15: YS), in step S16, the feature point position calculation unit 742 of the image analysis unit 74 calculates the feature points. The position of the corneal apex of the eye E is calculated based on the position corresponding to the feature point E0 of the eye E specified by the specifying unit 741. In step S <b> 16, the control device 7 determines at least one of the near vision table 42 and the target presentation optical system 5 based on the position of the corneal vertex of the eye E calculated by the feature point position calculation unit 742. The alignment operation is controlled.

  As a first specific example of the process of step S16, in the specific example shown in FIG. 6, the feature point position calculating unit 742 corresponds to the feature point E0 of the eye E to be examined specified by the feature point specifying unit 741 in step S161. The position of the corneal apex of the eye E in at least one of the horizontal direction X and the vertical direction Y is calculated on the basis of the position to be corrected. Subsequently, in step S162, the control device 7 controls the second reflection mirror driving unit 54 based on the position of the corneal apex of the eye E calculated by the feature point position calculating unit 742, so that the far vision The light beams emitted from the table 41 and the near vision table 42 are reflected toward the corneal apex of the eye E by the second reflecting mirror 53. In other words, the control device 7 controls the second reflection mirror driving unit 54 so that the light beams emitted from the distance vision table 41 and the near vision table 42 are cornea of the eye E to be examined via the second reflection mirror 53. Lead to the apex.

  Alternatively, as a second specific example of the process of step S16, in the specific example shown in FIG. 7, the feature point position calculation unit 742 is photographed substantially simultaneously by the first camera 61 and the second camera 62 in step S163. By analyzing the plurality of images, the position of the corneal apex of the eye E in the optical axis direction Z (the direction of the optical axis LA2 (see FIG. 2)) is calculated. Specifically, the feature point position calculation unit 742 corresponds to the positions of the first camera 61 and the second camera 62 and the feature point E0 in the plurality of images of the eye E specified by the feature point specification unit 741. Based on the position (for example, pupil position), the position of the corneal apex of the eye E in the optical axis direction Z is calculated. In other words, the feature point position calculation unit 742 calculates the position of the corneal vertex of the eye E in the optical axis direction Z based on the parallax between two images obtained from the positions of the first camera 61 and the second camera 62. Subsequently, in step S164, the control device 7 controls the near vision table drive unit 43 based on the position of the corneal apex of the eye E calculated by the feature point position calculation unit 742, thereby realizing near vision. The distance (optical path length) between Table 42 and the corneal apex of eye E is adjusted to a predetermined presentation distance.

  Note that the control device 7 controls the notification unit 83 to adjust the distance (optical path length) between the near vision 42 and the corneal apex of the eye E to be examined by voice or light by controlling the notification unit 83. Notification may be executed. According to this, for example, the examiner and the subject J can easily adjust the distance between the near vision 42 and the corneal apex of the eye E to a predetermined presentation distance, It is possible to confirm whether or not the distance between the table 42 and the corneal apex of the eye E matches a predetermined presentation distance.

  In step S17 following step S16 shown in FIG. 5, the control device 7 determines whether or not the positions of the optotype presenting optical system 5 and the near vision table 42 have converged. When the positions of the optotype presenting optical system 5 and the near vision table 42 have not converged (step S17: NO), the control device 7 executes the process described above with respect to step S16. On the other hand, when the positions of the optotype presenting optical system 5 and the near vision table 42 converge (step S17: YES), the operation example of the optotype presenting apparatus 2 shown in FIG. 5 ends. In addition, the control apparatus 7 can perform the tracking of the near vision table 42 and the optotype presenting optical system 5 with respect to the movement of the eye E by repeating the processes of steps S11 to S17.

  According to the operation example shown in FIGS. 5 and 6, the control device 7 changes the position of the optotype presenting optical system 5 to the change in the position of the feature point E0 of the eye E in at least one of the horizontal direction and the vertical direction. Can be followed. According to the operation example shown in FIGS. 5 and 7, the control device 7 determines the position of the near vision table 42 in the optical axis direction Z (direction of the optical axis LA2 (see FIG. 2)) of the visual target presenting optical system 5. Can follow the change in the position of the feature point E0 of the eye E to be examined.

  In the operation examples shown in FIGS. 5 to 7, when the near examination is performed, the control device 7 determines the near vision 42 and the optotype presenting optical system based on the position of the feature point E0 of the eye E. The example in which at least one of the alignment operations of 5 is performed has been described. However, the control device 7 is not limited to this, and when the distance examination is performed, the control device 7 determines at least one of the distance visual table 41 and the target presentation optical system 5 based on the position of the feature point E0 of the eye E. An alignment operation may be performed. That is, the control device 7 is radiated from the far vision table 41 by controlling the second reflecting mirror driving unit 54 based on the position of the corneal apex of the eye E calculated by the feature point position calculating unit 742. The reflected light beam may be reflected toward the corneal apex of the eye E by the second reflecting mirror 53. In addition, the control device 7 controls the distance visual table drive unit (not shown) based on the position of the corneal apex of the eye E calculated by the feature point position calculation unit 742, so The distance (optical path length) between the corneal apex of the optometry E may be set to a predetermined presentation distance.

  The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the claims. A part of the configuration of the above embodiment can be omitted, or can be arbitrarily combined so as to be different from the above.

DESCRIPTION OF SYMBOLS 2 ... Visual target presentation apparatus, 3 ... Housing | casing, 5 ... Visual target presentation optical system, 6 ... Image pick-up part, 7 ... Control apparatus, 8 ... User interface, 9 ...・ Optometry table, 41... Distance vision, 42 .. Near vision, 43 .. Near vision table drive unit, 51... First reflection mirror, 52. 2nd reflection mirror, 54 ... 2nd reflection mirror drive unit, 61 ... 1st camera, 62 ... 2nd camera, 63 ... Shooting drive unit, 64 ... Infrared illumination, 71 ... Calculation unit 72 ... Storage unit 73 ... Image processing unit 74 ... Image analysis unit 81 ... Operation unit 82 ... Display unit 83 ... Notification unit , 91... Support, 92. Subjective optometry means (refractor head), 93. Illumination unit, 411, 421. Display screen, 521... Focus, 531... Far-presenting position, 731... Image determination unit, 741... Feature point specifying unit, 742... Feature point position calculation unit, E. Optometry, E0 ... feature point, J ... subject, LA1, LA2 ... optical axis, W ... window, WD ... distance, X ... horizontal direction, Y ... vertical Direction, Z ... optical axis direction

Claims (7)

An optotype presenting apparatus for presenting an optotype attached to an eye chart for optometry toward an eye to be examined,
A housing,
A visual table provided inside the housing;
An optotype presenting optical system for presenting the light beam emitted from the visual table provided in the interior of the housing to the eye to be examined through an optical system disposed in the interior of the housing;
An imaging unit for imaging the eye to be examined;
An optotype presenting apparatus characterized by comprising:   Control for identifying the position of the eye to be examined by analyzing an image of the eye to be photographed by the photographing unit, and executing alignment control of the optotype presenting optical system based on the position of the eye to be examined The optotype presenting apparatus according to claim 1, further comprising an apparatus. The optotype presenting optical system is:
A reflecting member that reflects the luminous flux emitted from the visual table and presents it to the eye to be examined;
A reflecting member drive unit that rotates the reflecting member around at least one of a horizontal axis and a vertical axis;
Have
The control device identifies the position of the eye to be examined in at least one of the horizontal direction and the vertical direction by analyzing the image of the eye to be examined, and the reflection member based on the position of the eye to be examined The optotype presenting apparatus according to claim 2, wherein the luminous flux emitted from the visual table is reflected toward the eye to be examined by the reflecting member by controlling a driving unit.   The said imaging | photography part is arrange | positioned with respect to the said to-be-examined eye at the said visual surface side rather than the said reflecting member, and it was comprised so that imaging | photography of the to-be-examined eye was possible via the said reflecting member. Visual target presentation device. A near vision table drive unit that moves along the optical axis of the near vision table and the optotype presenting optical system inside the housing;
The photographing unit includes a first camera and a second camera that photograph the eye to be examined substantially simultaneously from different directions,
The control device identifies the position of the eye to be examined in the direction of the optical axis by analyzing a plurality of images taken substantially simultaneously by the first camera and the second camera, and The distance between the near vision table and the eye to be examined is adjusted to a predetermined presentation distance by controlling the near vision table driving unit based on the position. The optotype presenting apparatus according to any one of the above items.   2. The optotype presenting apparatus according to claim 1, further comprising a display unit that displays an image of the eye to be examined photographed by the photographing unit. Infrared illumination for irradiating infrared rays toward the eye to be examined is further provided,
The visual target presentation device according to claim 1, wherein the imaging unit is an infrared camera having sensitivity to the infrared rays emitted from the eye to be examined.

Images