Target presentation device

Abstract

To provide a target presentation device capable of preventing a positional deviation of an eye to be examined in a space-saving and low-cost manner.SOLUTION: A target presentation device includes: a display device (distant target 41) that emits a target light flux; a target presentation window W; a target presentation optical system 5 that guides the target light flux emitted from the display device to the target presentation window W; a position acquisition unit (second imaging unit 62, position detection unit 73) that acquires the position of an eye E to be examined; a determination unit 74 that determines whether the eye E to be examined is included within an examination possible range R based on the position of the eye to be examined acquired by the position acquisition unit; and a display control unit 70 that switches the display device to an examination mode for emitting the target light flux when the determination unit 74 determines that the eye to be examined is included within the examination possible range, and switches the display device to a position adjustment mode for emitting a light flux of a notification image 76 representing a positional relationship between the eye E to be examined and the examination possible range R when the determination unit determines that the eye to be examined is not included within the examination possible range.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an optotype presenting device that presents an optotype for testing an eye to be examined. [Background technology]

[0002] In ophthalmology clinics and eyeglass stores, optotype presenting devices (also called subjective optometry devices) that present various optotypes to the eye to be examined are installed in order to subjectively test the visual functions of the eye, such as the refractive power of the eye. For example, when an optotype presenting device presents an optotype for visual acuity testing, such as a Landolt ring, to the eye to be examined, the visual acuity of the eye to be examined can be tested based on the examinee's response to the optotype.

[0003] To measure the distance visual acuity of a subject's eye, a distance of about 5 m needs to be maintained between the optotype presenting device (optotype) and the subject's eye, but it may be difficult to secure this 5 m space depending on the size of the room in an ophthalmology clinic, eyeglass store, etc. Therefore, a space-saving optotype presenting device is known that optically presents an optotype at a predetermined test distance (5 m) to the subject's eye, that is, optically forms a virtual image of the optotype at a distance of 5 m from the subject's eye using a lens, thereby enabling installation at a short distance of less than 5 m from the subject's eye (see Patent Documents 1 and 2).

[0004] The optotype presenting device described in Patent Document 2 includes a movement mechanism that moves an optotype presenting optical system that presents an optotype to the eye to be examined, an alignment detection unit that detects the position of the eye to be examined, and an alignment control unit that drives the movement mechanism based on the detection result of the alignment detection unit to align the optotype presenting optical system with the eye to be examined, thereby preventing misalignment between the eye to be examined and the optotype presenting optical system. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-177045 [Patent Document 2] Japanese Patent Application Publication No. 2023-150640 Summary of the Invention [Problem to be solved by the invention]

[0006] In the optotype presenting device described in Patent Document 1, the subject's eye (examinee) views the optotype through a lens. Therefore, if the subject's eye views the optotype from a position or angle that is different from the appropriate position, the optotype will appear distorted due to lens aberration. For example, if the optotype is a Landolt ring used in visual acuity tests and the Landolt ring is small enough to correspond to a visual acuity value of 1.0 or higher, the Landolt ring may appear distorted, causing the subject to give an incorrect answer even if the subject actually has the visual acuity to answer correctly.

[0007] Therefore, it is conceivable to align the optotype presenting optical system with the subject's eye, as in the optotype presenting device described in Patent Document 2. However, in this case, it is necessary to provide the optotype presenting device with a movement mechanism for moving the optotype presenting optical system, which increases the size of the optotype presenting device and the manufacturing cost of the optotype presenting device.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optotype presenting device that is space-saving, low-cost, and capable of preventing positional deviation of the subject's eye. [Means for solving the problem]

[0009] To achieve the object of the present invention, an optotype presenting device includes a display device that emits optotype light beams of one or more optotypes for testing an eye to be examined, an optotype presenting window, and a visual target presenting window that projects the optotype light beams emitted from the display device onto the optotype. a position acquisition unit that repeatedly acquires at least the position of the eye to be examined; a determination unit that determines whether the eye to be examined is included in a predetermined testable range based on the position of the eye to be examined acquired by the position acquisition unit each time the position acquisition unit acquires the position of the eye to be examined; and a display control unit that switches the display device to an examination mode in which a test target light beam is emitted if the determination unit determines that the eye to be examined is included in the testable range, and switches to a position adjustment mode in which a light beam of an alert image representing at least the positional relationship between the eye to be examined and the testable range if the determination unit determines that the eye to be examined is not included in the testable range, wherein the test target presentation optical system guides the light beam of the alert image emitted from the display device in the position adjustment mode to the test target presentation window and presents the alert image to the eye to be examined through the test target presentation window.

[0010] According to this optotype presenting device, when the eye to be examined is not included in the testable range, a notification image is presented to the eye to be examined, thereby making it possible to prompt the subject to adjust the position of the face (eye to be examined).

[0011] In the optotype presenting device according to another aspect of the present invention, when the determination unit determines that the eye is not within the testable range, the position acquisition unit acquires the position of the eye to be examined, the determination unit makes a determination, and the display device emits a light beam of the notification image repeatedly until the determination unit determines that the eye to be examined is included in the testable range. As a result, the notification image can be continuously presented to the eye to be examined until the eye to be examined is included in the testable range, thereby prompting the subject to adjust the position of his or her face (eye to be examined).

[0012] In another aspect of the optotype presenting device of the present invention, the optotype is a first optotype for visual acuity measurement, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are predetermined, and the determination unit determines whether the subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype being presented to the subject's eye. This allows the determination unit to set an appropriate testable range corresponding to the visual acuity value of the first optotype being presented to the subject's eye (the size of the first optotype).

[0013] In another aspect of the present invention, the optotype presenting device includes a first optotype and a second optotype for testing that is different from the first optotype, and the determination unit determines whether the eye to be examined is included in an examination range corresponding to the visual acuity value of the first optotype last presented to the eye to be examined while the second optotype is being presented to the eye to be examined. This makes it possible to determine whether the eye to be examined is included in the examination range corresponding to the visual acuity value of the eye to be examined even while the second optotype is being presented.

[0014] In another aspect of the present invention, the optotype presenting device includes an alert image generating unit that generates an alert image including a first image indicating the position of the subject's eye and a second image indicating the testable range based on the position of the subject's eye newly acquired by the position acquiring unit each time the position acquiring unit acquires a new position of the subject's eye when the determining unit determines "No," and the display device in the position adjustment mode emits a light beam of the alert image newly generated by the alert image generating unit each time the alert image is generated by the alert image generating unit, thereby allowing the subject to easily recognize the positional relationship between the subject's eye and the testable range.

[0015] In another aspect of the optotype presenting device of the present invention, the optotype is a first optotype for measuring visual acuity, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are predetermined, the determination unit determines whether the test subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype being presented to the test subject's eye, and if the determination unit determines that the first optotype is not included during the presentation of the first optotype to the test subject's eye, the notification image generation unit generates a second image indicating the testable range corresponding to the visual acuity value of the first optotype being presented. This allows the test subject to easily recognize the testable range used by the determination unit for the determination.

[0016] In another aspect of the present invention, the optotype presenting device includes a first optotype and a second optotype for a test other than visual acuity measurement, and the determination unit determines whether the first optotype and the second optotype are presenting to the subject's eye while the second optotype are being presented. The notification image generating unit determines whether the subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype last presented to the eye, and if the determining unit determines that the testable range is not included during the presentation of the second optotype to the subject's eye, the notification image generating unit generates a second image indicating the testable range corresponding to the visual acuity value of the first optotype last presented to the subject's eye. This makes it possible to present the testable range corresponding to the visual acuity value of the subject's eye to the subject's eye even during the presentation of the second optotype.

[0017] In another aspect of the present invention, the position acquisition unit includes a photographing unit that photographs the face of the subject and a position detection unit that detects the position of at least the eye to be examined based on the image photographed by the photographing unit, and the notification image generation unit generates a facial image of the subject as a first image based on the image photographed by the photographing unit, thereby making it possible to notify the subject of the relative position of the face (eye to be examined) with respect to the examination range using the facial image of the subject.

[0018] In another aspect of the optotype presenting device of the present invention, the optotype is a first optotype for visual acuity measurement, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are predetermined, a position detection unit detects the position of the eye to be examined and the position of the subject's face, and among the plurality of testable ranges, a testable range corresponding to a specific optotype that is the first optotype with a visual acuity value equal to or less than the predetermined visual acuity value indicates an acceptable range for the face position, a determination unit determines whether the eye to be examined is included in the testable range based on the position detection result of the position detection unit while the specific optotype is being presented to the eye to be examined depending on whether the face is included in the acceptable range, and an alert image generation unit generates a second image indicating the acceptable range if the determination unit determines no while the specific optotype is being presented to the eye to be examined. As a result, it is possible to determine whether the eye to be examined is included in the testable range depending on whether the subject's face is included in the acceptable range while the specific optotype is being presented to the eye to be examined.

[0019] In another aspect of the optotype presenting device of the present invention, when the display device is in the position adjustment mode and the determination unit determines that the test eye is included in the testable range, the notification image generation unit changes the display mode of the second image, and then the display control unit switches the display device to the test mode. This makes it possible to notify the test subject that the position adjustment of the face (test eye) has been completed before switching the display device to the test mode. [Effects of the Invention]

[0020] The present invention can prevent the positional deviation of the eye to be examined in a space-saving and low-cost manner. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of the appearance of an optotype presenting device. [Figure 2] FIG. 2 is a block diagram showing the internal configuration of a housing of the optotype presenting device. [Figure 3] FIG. 2 is a block diagram of a visual target presenting device. [Figure 4] 1 is a diagram showing an example of a visual acuity measurement target (Landolt ring) presented to the subject's eye by a distance chart in a test mode. FIG. [Figure 5] 10A and 10B are diagrams showing examples of a red-green test optotype chart, a radiation chart, and a dot cloud chart that are presented to the subject's eye by a distance optotype in a test mode. [Figure 6] 10 is a diagram showing an example of a first inspectable range, a second inspectable range, and a third inspectable range. FIG. [Figure 7] FIG. 10 is a diagram showing an example of a first notification image. [Figure 8] 10 is a diagram showing an example of a first notification image generated by a notification image generating unit when the face of a subject moves from outside the first inspectable range to inside the first inspectable range. FIG. [Figure 9] FIG. 10 is a diagram showing an example of a second notification image. [Figure 10] FIG. 10 is a diagram showing an example of a second notification image generated by the notification image generating section 75 when the eye to be examined moves from outside the second testable range to within the range. [Figure 11] FIG. 10 is a diagram showing an example of a third notification image. [Figure 12] 10 is a diagram showing an example of a third notification image generated by the notification image generating unit when the subject's eye moves from outside the third testable range to within the range. FIG. [Figure 13] 1 is a flowchart showing the flow of a distance vision test using an optotype presenting device. [Figure 14] 10 is a flowchart showing the flow of a distance vision test other than a distance visual acuity test using an optotype presenting device. DETAILED DESCRIPTION OF THE INVENTION

[0022] 1 is a perspective view of the appearance of the optotype presenting device 2. Of the three mutually orthogonal X, Y, and Z directions in the figure, the Y direction is the up-down direction, the Z direction is the front-back direction moving toward or away from a subject J (see FIG. 2), and the X direction is the left-right direction perpendicular to both the up-down direction and the front-back direction.

[0023] As shown in Fig. 1, the optotype presenting device 2 presents one or more optotypes attached to an optotype chart (such as an eye chart) for testing the eye E (see Fig. 2) to the eye E through an optotype presenting window W provided on the front side of the housing 3. An optometry table 9 is disposed in front of the housing 3. The optotype presenting device 2 may be a tabletop type disposed on the optometry table 9.

[0024] The optometry table 9 has a support 91, a refractor head 92 used for subjective optometry, and an illumination unit 93. The support 91 is rotatable about an axis parallel to the Y direction. The refractor head 92 and the illumination unit 93 are supported by the support 91. The refractor head 92 may be attached to the housing 3 of the optotype presenting device 2, or may be configured so that the refractor head 92 can be inserted into and removed from in front of the subject's eye E (see FIG. 2).

[0025] Fig. 2 is a block diagram showing the internal configuration of the housing 3 of the optotype presenting device 2. As shown in Fig. 2, an optotype presenting window W is provided on the front surface of the housing 3 at a position facing the face F of the subject J. In addition, casters 31 are provided on the bottom surface of the housing 3.

[0026] Inside the housing 3, a far vision chart 41, a near vision chart 42, a target presenting optical system 5, a first photographing unit 61, a second photographing unit 62, and a control device 7 are provided.

[0027] The optotype presenting window W is made of a translucent resin such as polyacrylate resin and has a thickness of about 2 mm. In the optotype presenting device 2 of this embodiment, the near vision optotype 42 is provided inside the housing 3, so that the distance (working distance) WD between the corneal vertex of the subject's eye E and the front surface of the housing 3 can be set to be less than the near vision optometry distance.

[0028] The casters 31 are used to move the optotype presenting device 2. The casters 31 may be omitted.

[0029] The distance optotype 41 corresponds to the display device of the present invention. This distance optotype 41 is an optotype for distance vision testing, and presents one or more optotypes to the subject's eye E. For example, the distance optotype 41 is an electronic display device such as a liquid crystal display device, and has a display screen 411 that displays optotypes such as Landolt rings. Note that the distance optotype 41 is not limited to a liquid crystal display device, and may be any other display device capable of displaying various images.

[0030] The near optotype 42 is an optotype for near vision testing, and presents an optotype to the subject's eye E. For example, the near optotype 42 is an electronic display device such as a liquid crystal display device, and is provided with a display screen 421 that displays an optotype such as a Landolt ring. Note that the near optotype 42 is not limited to a liquid crystal display device, and may be another display device, or may be formed from a glass plate or paper on which an optotype pattern is drawn.

[0031] The optotype presenting optical system 5 presents the optotype to the subject's eye E by guiding the light beams emitted from the distance vision table 41 and the near vision table 42 to the optotype presenting window W via an optical system arranged inside the housing 3. The optotype presenting optical system 5 has a first reflecting mirror 51, a convex lens system 52, and a second reflecting mirror 53, which are arranged along an optical axis LA1 parallel to the Y direction.

[0032] The first reflecting mirror 51 reflects the light beam emitted from the distance viewing 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 distance viewing table 41 is disposed between the convex lens system 52 and a focal point 521 of the convex lens system 52. The convex lens system 52 is not limited to the single plano-convex lens shown in FIG. 2, and may include multiple lenses.

[0033] When a distance vision test is performed, the second reflecting mirror 53 reflects the light beam transmitted through the convex lens system 52 along an optical axis LA2 parallel to the X direction toward the subject's eye E, and presents a virtual image at a distance presentation position 531 that is a predetermined distance in front of the corneal apex of the subject's eye E. The distance between the corneal apex of the subject's eye E and the distance presentation position 531 is approximately 5 m.

[0034] When a near vision test is performed, the second reflecting mirror 53 reflects the light beam emitted from the near vision table 42 and presents it to the subject's eye E. The near vision table 42 is provided on the light emission side of the convex lens system 52. Therefore, the light beam emitted from the near vision table 42 is not reflected by the first reflecting mirror 51 or transmitted through the convex lens system 52.

[0035] The first photographing unit 61 photographs the subject's eye E (the face F of the subject J). The first photographing unit 61 is disposed closer to the near vision table 42 than the second reflecting mirror 53 with respect to the subject's eye E, and photographs the subject's eye E via the second reflecting mirror 53. The first photographing unit 61 of this embodiment is provided between the convex lens system 52 and the near vision table 42. The first photographing unit 61 is composed of, for example, multiple cameras, and each camera photographs the subject's eye E (face F) from different directions substantially simultaneously, and outputs the photographed images (still images or moving images) (see Patent Document 1 above). The first photographing unit 61 may also be composed of a single camera.

[0036] The second photographing unit 62 corresponds to the photographing unit of the present invention and photographs the subject's eye E (face F). For example, the second photographing unit 62 is provided at a position opposite to the side facing the optotype presenting window W when viewed from the second reflecting mirror 53. The second photographing unit 62 is composed of, for example, a plurality of cameras, each of which photographs the subject's eye E (face F) from a different oblique direction substantially simultaneously, and outputs the photographed images (still images, moving images) (see Patent Document 1 above). Note that the second photographing unit 62 may be composed of a single camera.

[0037] As described in Patent Document 1, the angle of view of the first photographing unit 61 and the angle of view of the second photographing unit 62 may be different from each other. When infrared cameras are used as the cameras constituting the first photographing unit 61 and the second photographing unit 62, the subject's eye E may be illuminated with infrared light emitted from an infrared light source 64 provided in the housing 3 (or the refractor head 92), and the subject's eye E may be photographed by each camera.

[0038] The control device 7 is connected to each unit in the housing 3 and controls the overall operation of the optotype presenting device 2 including these units.

[0039] Fig. 3 is a block diagram of the optotype presenting device 2. As shown in Fig. 3, in addition to the components in the housing 3 shown in Fig. 2, the control device 7 is connected with a near vision table moving unit 43, a second reflecting mirror driving unit 54, an operation unit 8A, and a display unit 8B.

[0040] The near chart moving unit 43 moves the near chart 42 and the first photographing unit 61 away from the optical axis LA1 (on the optical path of the light beam emitted from the far chart 41) during a distance vision test, and inserts the near chart 42 and the first photographing unit 61 onto the optical axis LA1 during a near vision test. Note that if the near chart 42 and the first photographing unit 61 are positioned at a position other than on the optical axis LA1 during a near vision test, the near chart moving unit 43 can be omitted.

[0041] The second reflecting mirror driving unit 54 rotates the second reflecting mirror 53 around a rotation center parallel to the X direction and around a rotation center parallel to the Y direction under the control of the control device 7. The second reflecting mirror driving unit 54 may be omitted.

[0042] The operation unit 8A is made up of various buttons and keys provided on the housing 3, etc., and accepts input of various operations by the examiner. The display unit 8B is an electronic display device such as a liquid crystal display device, and displays various setting screens of the optotype presenting device 2 or the observation images captured by the first photographing unit 61 and the second photographing unit 62.

[0043] The control device 7 includes an arithmetic circuit configured with various processors, memories, etc. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., simple programmable logic device (SPLD), complex programmable logic device (CPLD), and field programmable gate array (FPGA)). The various functions of the control device 7 may be realized by a single processor, or by multiple processors of the same or different types.

[0044] The control device 7 functions as a display control unit 70, a shooting control unit 71, a shooting image acquisition unit 72, a position detection unit 73, a determination unit 74, and an alarm image generation unit 75 by reading and executing a control program not shown.

[0045] The display control unit 70 controls the emission of the light beam from the near vision table 42 and the emission of the light beam from the far vision table 41. During a near vision test of the subject's eye E, the display control unit 70 causes target light beams of one or more targets for the near vision test to be emitted from the near vision table 42. As a result, the target presenting optical system 5 presents one or more targets for the near vision test to the subject's eye E through the target presenting window W.

[0046] Furthermore, during a distance vision test of the subject's eye E, the display control unit 70 switches the operation mode of the distance vision table 41 between a test mode and a position adjustment mode based on the determination result of a determination unit 74 described later.

[0047] Fig. 4 is a diagram showing an example of a visual acuity measurement optotype 45a (Landolt ring) that the distance optotype 41 in the test mode presents to the subject's eye E. Fig. 5 is a diagram showing an example of a red-green test optotype chart 46A, a radiation chart 46B, and a point cloud chart 46C that the distance optotype 41 in the test mode presents to the subject's eye E.

[0048] 4, during a visual acuity test (distance visual acuity test) of the eye E, the distance chart 41 in the test mode emits a light beam of one or more visual acuity measurement targets 45a (corresponding to the first visual target of the present invention), such as one or more Landolt rings, attached to the visual acuity measurement visual acuity chart 45, in response to a visual acuity value selection operation on the operation unit 8A. As a result, the one or more visual acuity measurement targets 45a are presented to the eye E through the target presenting window W by the target presenting optical system 5.

[0049] As shown in FIG. 5, the distance chart 41 in the test mode emits a light beam of a chart for testing the subject's eye E other than for visual acuity testing, in response to a chart selection operation on the operation unit 8A. For example, the distance chart 41 emits a light beam from a red-green test optotype chart 46A when adjusting the spherical power of the eye E (see symbol VA), emits a light beam from a radiation chart 46B when checking the astigmatic axis of the eye E (see symbol VB), and emits a light beam from a point cloud chart 46C when fine-tuning the astigmatic power and astigmatic axis of the eye E (see symbol VC). As a result, the optotype chart selected by the examiner is presented to the eye E by the optotype presenting optical system 5 through the optotype presenting window W. The red-green test optotype chart 46A, the radiation chart 46B, and the point cloud chart 46C correspond to the second optotype of the present invention.

[0050] During a distance vision test, the subject's eye E views the visual acuity measurement optotype 45a or optotype chart through a convex lens system 52. The higher the visual acuity value, the smaller the size of the visual acuity measurement optotype 45a. Therefore, if the subject's eye E views the visual acuity measurement optotype 45a from a position that is shifted from the appropriate position, the visual acuity measurement optotype 45a will appear distorted due to the aberration of the lenses in the convex lens system 52. As a result, there is a risk that the subject J will give an incorrect answer, even though he or she actually has the visual acuity to answer correctly.

[0051] Therefore, in this embodiment, by repeatedly acquiring the position of the subject's eye E during a distance vision test such as a distance visual acuity test, it is repeatedly determined whether the subject's eye E is included in an examination range R (see FIG. 6 ), which is the allowable value for the distance vision test, and if the subject's eye E is not included in the examination range R, the distance chart 41 is switched to a position adjustment mode. The distance chart 41 in the position adjustment mode, which will be described in detail later, emits a light beam of an image showing that the subject's eye E is not included in the examination range R and showing the positional relationship between the subject's eye E (face F) and the examination range R under the control of the display control unit 70.

[0052] Returning to Figure 3, during the distance vision test (during the test mode for the distance chart 41), the photographing control unit 71 activates the second photographing unit 62, causing the second photographing unit 62 to repeatedly photograph the face F (including the eye E) of the subject J, i.e., to perform video photographing of the face F.

[0053] The captured image acquisition unit 72 acquires a captured image of the face F from the second photographing unit 62 and repeatedly outputs the image to the position detection unit 73 each time the second photographing unit 62 photographs the face F during the far vision test. In addition, when the far vision table 41 is in the position adjustment mode, the captured image acquisition unit 72 also repeatedly outputs the captured image of the face F to the notification image generation unit 75, which will be described later.

[0054] The position detection unit 73, together with the second photographing unit 62, constitutes the position acquisition unit of the present invention. Every time a photographed image of the face F is input from the photographed image acquisition unit 72, the position detection unit 73 repeatedly detects at least the position (three-dimensional position) of the subject's eye E based on this photographed image. The method of detecting the position of the subject's eye E by analyzing the photographed image taken by the second photographing unit 62, which is composed of two or more cameras, is a publicly known technique (see, for example, Japanese Patent Application Laid-Open No. 2014-200678), and therefore a detailed description thereof will be omitted here.

[0055] Furthermore, the position detection unit 73 simultaneously detects the position (three-dimensional position) of the face F of the subject J based on the photographed image of the face F input from the photographed image acquisition unit 72. Note that the method for detecting the position of the face F from the photographed image photographed by the second photographing unit 62 is also a well-known technique, and therefore a detailed description thereof will be omitted here.

[0056] In this way, the position detection unit 73 repeatedly detects the positions of the subject's eye E and face F during the distance vision test, and repeatedly outputs the position detection results of the subject's eye E and face F to the determination unit 74. In addition, when the distance vision table 41 is in the position adjustment mode, the position detection unit 73 also repeatedly outputs the position detection results of the subject's eye E and face F to the notification image generation unit 75.

[0057] Each time the position detection unit 73 detects the positions of the subject's eye E and face F during the far vision test, the determination unit 74 determines whether the subject's eye E and face F are within a predetermined testable range R (see FIG. 6) based on the detection result of the position detection unit 73. It is determined whether the subject's eye E is included in the range R. When a distance vision test is performed as the distance vision test, the size of the visual acuity test target 45a becomes smaller as the visual acuity value increases (see FIG. 4). For this reason, the testable range R required when presenting the visual acuity test target 45a corresponding to a high visual acuity value must be set narrower than the testable range required when presenting the visual acuity test target 45a corresponding to a low visual acuity value.

[0058] 6, which will be described later, a first testable range R1, a second testable range R2, and a third testable range R3 are set as the testable range R. The testable range R has three different sizes (two or four or more ranges are also possible) depending on the size (visual acuity value) of the visual acuity measurement target 45a. The determination unit 74 then determines whether the subject's eye E is included in the testable range R corresponding to the size of the visual acuity measurement target 45a being presented to the subject's eye E.

[0059] FIG. 6 is a diagram showing examples of the first testable range R1, the second testable range R2, and the third testable range R3. As shown in FIG. 6 and the previously described FIG. 3, the first testable range R1 is the widest of the ranges and is selected, for example, when a large-sized optotype 45a for measuring vision (corresponding to the specific optotype of the present invention) having a visual acuity value equal to or less than a predetermined value (e.g., 0.6 or less) is presented to the subject's eye E. The first testable range R1 is set to be wider than the face F and indicates the allowable range for the position of the face F. While the visual acuity measurement optotype 45a having a visual acuity value of 0.6 or less is being presented, the determination unit 74 determines whether the subject's eye E is included in the testable range R based on the detection result of the position of the face F by the position detection unit 73, depending on whether the face F is included in the first testable range R1.

[0060] The first testable range R1 may indicate the allowable range of the position of the eye E to be inspected, instead of the allowable range of the position of the face F.

[0061] The second testable range R2 is a medium-sized range among the ranges, and is selected, for example, when a medium-sized visual acuity measurement target 45a with a visual acuity value of 0.7 to 0.9 is presented to the subject's eye E. While the visual acuity measurement target 45a with a visual acuity value of 0.7 to 0.9 is being presented, the determination unit 74 determines whether the subject's eye E is included in the second testable range R2 (testable range R) based on the detection result of the position of the subject's eye E by the position detection unit 73.

[0062] The third testable range R3 is the narrowest range among all the ranges, and is selected, for example, when a small-sized visual acuity measurement target 45a with a visual acuity value of 1.0 or more is presented to the subject's eye E. While the visual acuity measurement target 45a with a visual acuity value of 1.0 or more is being presented, the determination unit 74 determines whether the subject's eye E is included in the third testable range R3 (testable range R) based on the detection result of the position of the subject's eye E by the position detection unit 73.

[0063] 5 is being presented, the determination unit 74 selects the testable range R corresponding to the visual acuity value (size) of the visual acuity measurement test target 45a last presented to the subject's eye E from among the first testable range R1, the second testable range R2, and the third testable range R3. Then, based on the detection result of the position detection unit 73, the determination unit 74 determines whether the subject's eye E is included in the selected testable range R.

[0064] If the determination unit 74 determines that the subject's eye E is included in the testable range R, the display control unit 70 switches the operation mode of the distance vision table 41 to the test mode. If the determination unit 74 determines that the subject's eye E is not included in the testable range R, the display control unit 70 switches the operation mode of the distance vision table 41 to the position adjustment mode.

[0065] Returning to FIG. 3, when the operation mode of the distance vision table 41 is the position adjustment mode, that is, when the determination unit 74 determines that the eye E is not included in the testable range R, the notification image generation unit 75 The generation of the notification image 76 (see FIGS. 7 to 12) showing that the subject's eye E (face F) is not included and the positional relationship between the subject's eye E (face F) and the testable range R is repeatedly executed.

[0066] Specifically, the notification image generating unit 75 repeatedly receives input of the position detection results of the subject's eye E and face F from the position detecting unit 73 described above, and also repeatedly receives input of the photographed image of the face F from the photographed image acquiring unit 72. The inspectable range R used for the judgment by the judging unit 74 is known. Therefore, every time the notification image generating unit 75 receives input of the position detection results of the subject's eye E and face F and the photographed image of the face F, it repeatedly generates the notification image 76 based on these position detection results, the photographed image, and the current inspectable range R.

[0067] 7 to 12, the notification images 76 include a first notification image 76A corresponding to the first inspectable range R1, a second notification image 76B corresponding to the second inspectable range R2, and a third notification image 76C corresponding to the third inspectable range R3. The number of types of notification images 76 increases or decreases depending on the number of types of inspectable ranges R.

[0068] 7 is a diagram showing an example of a first notification image 76A. As shown in Fig. 7, when the determination unit 74 determines that the face F is not included in the first inspectable range R1, the notification image generation unit 75 generates a first notification image 76A based on the first inspectable range R1, the position detection result newly input from the position detection unit 73, and the captured image of the face F newly input from the captured image acquisition unit 72.

[0069] The first notification image 76A includes a face image 80 (corresponding to the first image of the present invention) of subject J generated based on a captured image of face F, a range image 82A (corresponding to the second image of the present invention) showing the first inspectable range R1, and a warning message 84 urging subject J to adjust the position of face F.

[0070] The face image 80 in the first notification image 76A is an image that indicates the relative position of the face F (subject's eye E) with respect to the first testable range R1. The range image 82A is, for example, a red dashed frame. It is preferable that the face image 80 and the range image 82A have a shape and color that are easy to see even for the subject's eye E with low visual acuity.

[0071] The position of the face image 80 within the first notification image 76A is determined based on the latest position detection result by the position detection unit 73. As a result, the direction and amount of displacement of the face image 80 relative to the range image 82A are adjusted according to the direction and amount of displacement of the face F relative to the first inspectable range R1. Therefore, the first notification image 76A is an image that notifies that the face F is not included in the first inspectable range R1, and also an image that represents the positional relationship between the face F (the subject's eye E) and the first inspectable range R1. Furthermore, the first notification image 76A represents the direction and amount of movement required to move the face F within the first inspectable range R1, i.e., the appropriate position and height of the face F.

[0072] Every time the position detection result and the photographed image of the face F are input from the position detection unit 73 and the photographed image acquisition unit 72, the notification image generation unit 75 generates a new first notification image 76A that reflects the latest position of the face F, based on the position detection result and the photographed image of the face F. As a result, when the subject J moves his / her face F after looking at the first notification image 76A, the position of the face image 80 in the first notification image 76A newly generated by the notification image generation unit 75 also moves in the same direction by the same amount.

[0073] FIG. 8 is a diagram showing an example of a first notification image 76A generated by the notification image generating section 75 when the face F of the subject J moves from outside the first inspectable range R1 to inside the range.

[0074] As shown in FIG. 8, when the distance vision table 41 is in the position adjustment mode, if the determination unit 74 newly determines that the face F is included in the first testable range R1, the notification image generation unit 75 changes the display mode of the range image 82A in the first annunciation image 76A. For example, the annunciation image generation unit 75 changes the range image 82A from a red dashed frame to a green solid frame. In addition, the annunciation image generation unit 75 changes the warning message 84 in the first annunciation image 76A to a completion message 85 indicating that the position adjustment of the face F has been completed.

[0075] Fig. 9 is a diagram showing an example of the second notification image 76B. Fig. 10 is a diagram showing an example of the second notification image 76B generated by the notification image generating unit 75 when the subject's eye E moves from outside the second testable range R2 to inside the range.

[0076] As shown in Figure 9, when the judgment unit 74 determines that the test eye E is not included in the second testable range R2, the notification image generation unit 75 generates a second notification image 76B based on the second testable range R2, the position detection result newly input from the position detection unit 73, and the captured image of the face F newly input from the captured image acquisition unit 72.

[0077] The second notification image 76B includes the face image 80, a range image 82B (corresponding to the second image of the present invention) indicating the second inspectable range R2, and the warning message 84. The range image 82B has, for example, a red dashed oval shape.

[0078] The position of the face image 80 within the second notification image 76B is determined based on the latest position detection result by the position detection unit 73, as with the first notification image 76A. As a result, the direction and amount of displacement of the face image 80 (image of the subject's eye E) relative to the range image 82B are adjusted according to the direction and amount of displacement of the face F (subject's eye E) relative to the second inspectable range R2. Therefore, the second notification image 76B is an image that notifies the user that the subject's eye E is not included in the second inspectable range R2, and also represents the positional relationship between the subject's eye E and the second inspectable range R2. Furthermore, the second notification image 76B represents the direction and amount of movement required to move the subject's eye E into the second inspectable range R2, i.e., the appropriate position and height of the subject's eye E.

[0079] Every time the position detection result and the photographed image of the face F are input from the position detection unit 73 and the photographed image acquisition unit 72, the notification image generation unit 75 generates a new second notification image 76B that reflects the latest position of the face F (subject's eye E) based on the position detection result and the photographed image of the face F. As a result, when the subject J moves his / her face F (subject's eye E) after looking at the second notification image 76B, the position of the face image 80 in the second notification image 76B newly generated by the notification image generation unit 75 also moves in the same direction by the same movement amount.

[0080] As shown in Figure 10, when the distance vision table 41 is in position adjustment mode, if the judgment unit 74 newly determines that the test eye E is included in the second testable range R2, the notification image generation unit 75 changes the display mode of the range image 82B to, for example, a green solid oval shape and changes the warning message 84 to a completion message 85.

[0081] Fig. 11 is a diagram showing an example of the third notification image 76C. Fig. 12 is a diagram showing an example of the third notification image 76C generated by the notification image generating unit 75 when the subject's eye E moves from outside the third testable range R3 to inside the range.

[0082] As shown in Figure 11, when the judgment unit 74 determines that the test eye E is not included in the third testable range R3, the notification image generation unit 75 generates a third notification image 76C based on the third testable range R3, the position detection result newly input from the position detection unit 73, and the captured image of the face F newly input from the captured image acquisition unit 72.

[0083] The third notification image 76C includes the face image 80 described above, a range image 82C (corresponding to the second image of the present invention) showing the third inspectable range R3, and the warning message 84 described above. 2C is an image representing the narrowest third inspectable range R3, and therefore has, for example, the shape of glasses drawn in red dashed lines.

[0084] The position of the face image 80 within the third alert image 76C is determined based on the latest position detection result by the position detection unit 73, as with the first alert image 76A and the second alert image 76B. As a result, the direction and amount of displacement of the face image 80 (image of the subject's eye E) relative to the range image 82C are adjusted according to the direction and amount of displacement of the face F (subject's eye E) relative to the third inspectable range R3. Therefore, the third alert image 76C is an image that notifies the user that the subject's eye E is not included in the third inspectable range R3, and also represents the positional relationship between the subject's eye E and the third inspectable range R3. Furthermore, the third alert image 76C represents the direction and amount of movement required to move the subject's eye E into the third inspectable range R3, i.e., the appropriate position and height of the subject's eye E.

[0085] Every time the position detection result and the photographed image of the face F are input from the position detection unit 73 and the photographed image acquisition unit 72, the notification image generation unit 75 generates a new third notification image 76C that reflects the latest position of the face F (subject's eye E) based on the position detection result and the photographed image of the face F. As a result, when the subject J moves his / her face F (subject's eye E) after looking at the third notification image 76C, the position of the face image 80 in the third notification image 76C newly generated by the notification image generation unit 75 also moves in the same direction by the same movement amount.

[0086] As shown in Figure 12, when the distance vision table 41 is in position adjustment mode and the judgment unit 74 newly determines that the subject's eye E is included in the third testable range R3, the notification image generation unit 75 changes the display mode of the range image 82C to, for example, a green solid line eyeglass shape and changes the warning message 84 to a completion message 85.

[0087] 3, the distance chart 41, which has been switched to the position adjustment mode by the display control unit 70, emits a light beam of the newly generated notification image 76 every time the notification image generating unit 75 generates the notification image 76. As a result, the notification image 76 is presented to the subject's eye E through the target presenting window W by the target presenting optical system 5.

[0088] For example, when the testable range R is the first testable range R1, a first notification image 76A is presented to the test subject's eye E; when it is the second testable range R2, a second notification image 76B is presented to the test subject's eye E; and when it is the third testable range R3, a third notification image 76C is presented to the test subject's eye E. This makes it possible to prompt the test subject J to adjust the position of the face F. Furthermore, when the test subject's eye E moves into the testable range R while the notification image 76 is being presented to the test subject's eye E, the display mode of the range images 82A to 82C in the notification image 76 changes, and the warning message 84 changes to a completion message 85. As a result, the test subject J can recognize that the test subject's eye E (face F) has moved to the appropriate position.

[0089] When the determination unit 74 newly determines that the subject's eye E is included in the testable range R while the distance chart 41 is in the position adjustment mode, the display control unit 70 switches the distance chart 41 from the position adjustment mode to the test mode. At this time, the display control unit 70 switches the distance chart 41 to the test mode a predetermined period after the notification image generation unit 75 changes the display mode of the range images 82A to 82C and changes it to the completion message 85. That is, the display control unit 70 switches the distance chart 41 to the test mode after the notification image 76 including the range images 82A to 82C after the change in display mode and the completion message 85 are presented to the subject's eye E.

[0090] FIG. 13 is a flowchart showing the flow of a distance visual acuity test using the optotype presenting device 2 having the above-described configuration.

[0091] 13, when the examiner operates the operation unit 8A to start the distance vision test (step S1), the display control unit 70 operates the distance chart 41 in the test mode. Then, in response to a visual acuity value selection operation on the operation unit 8A, the distance chart 41 in the test mode emits a light beam of one or more visual acuity measurement targets 45a selected by the visual acuity value selection operation. As a result, the target presenting optical system 5 presents one or more visual acuity measurement targets 45a to the subject's eye E through the target presenting window W, thereby starting the distance vision test of the subject's eye E (step S2).

[0092] Furthermore, the photographing control unit 71 causes the second photographing unit 62 to repeatedly photograph the face F in response to the operation to start the visual acuity test (step S3). As a result, the photographed image acquisition unit 72 repeatedly acquires the photographed image of the face F from the second photographing unit 62 and transfers this photographed image to the position detection unit 73.

[0093] Then, each time a photographed image of the face F is input from the photographed image acquisition unit 72, the position detection unit 73 repeatedly detects the positions of the subject's eye E and face F based on the new photographed image and outputs these position detection results to the judgment unit 74 (step S4).

[0094] The determination unit 74 checks the visual acuity value (size) of the visual acuity measurement optotype 45a being presented to the subject's eye E, and selects an examination range R (one of the first examination range R1, the second examination range R2, and the third examination range R3) corresponding to the visual acuity value of the visual acuity measurement optotype 45a (step S5). Then, each time a new position detection result is input from the position detection unit 73, the determination unit 74 determines whether the subject's eye E is included in the examination range R based on the position detection result (step S6). Then, if the determination unit 74 determines that the subject's eye E is included in the examination range R, the process proceeds to step S16, which will be described later (YES in step S6).

[0095] On the other hand, if the determination unit 74 determines that the distance vision table 41 is not detected (NO in step S6), the display control unit 70 switches the operation mode of the distance vision table 41 from the examination mode to the position adjustment mode (step S7). In this case, the second image capturing unit 62 continues capturing an image of the face F (step S8), and the captured image capturing unit 72 repeatedly captures an image of the face F and outputs the captured image to the position detecting unit 73 and the notification image generating unit 75. The position detecting unit 73 repeatedly detects the positions of the subject's eye E and the face F, and the position detecting unit 73 repeatedly outputs the position detection results to the determination unit 74 and the notification image generating unit 75 (step S9).

[0096] Furthermore, each time the notification image generation unit 75 receives input of the position detection result and the captured image of the face F from the position detection unit 73 and the captured image acquisition unit 72, it repeatedly generates a notification image 76 (one of the first notification image 76A to the third notification image 76C) based on these position detection results and the captured image of the face F and the current inspectable range R (step S10).

[0097] Then, the distance chart 41 in the position adjustment mode emits a light beam of the newly generated notification image 76 every time the notification image generating unit 75 generates a notification image 76. As a result, the notification image 76 is presented to the subject's eye E through the target presenting window W by the target presenting optical system 5 (step S11). As a result, the subject J is notified that the subject's eye E is not included in the testable range R, and the subject J is prompted to adjust the position of his or her face F.

[0098] In this case, the notification image 76 uses the face image 80 and range images 82A to 82C to indicate the positional relationship between the subject's eye E and the testable range R. Even if the subject J were informed of the above-mentioned positional relationship using only text information such as the warning message 84, it would be meaningless for the subject's eye E undergoing a visual acuity test (for example, the subject's eye E with low visual acuity while the prescription of his or her glasses is being determined). In contrast, by presenting the notification image 76 including the face image 80 and range images 82A to 82C to the subject's eye E, the subject J can easily recognize the above-mentioned positional relationship.

[0099] The subject J adjusts the position of the face F while looking at the notification image 76, thereby adjusting the position of the subject's eye E within the testable range R. This allows the subject J to adjust the position of the subject's eye E to an appropriate position for the distance vision test, preventing the subject's eye E from shifting out of the testable range R.

[0100] Thereafter, the processes from step S8 to step S11 described above are repeatedly executed until the determination unit 74 determines that the eye E is included in the testable range R (NO in step S12).

[0101] When the determination unit 74 determines that the subject's eye E is included in the testable range R (YES in step S12), the notification image generation unit 75 changes the display mode of the range images 82A to 82C in the notification image 76 and changes the warning message 84 to a completion message 85 (step S13). Then, the distance vision chart 41 emits a light beam of the notification image 76 including the range images 82A to 82C after the display mode change and the completion message 85, and the notification image 76 is presented to the subject's eye E through the target presenting window W by the target presenting optical system 5. This allows the subject J to recognize that the subject's eye E (face F) has moved to the appropriate position.

[0102] Next, after a predetermined period of time has elapsed, the display control unit 70 switches the distance chart 41 from the position adjustment mode to the test mode (step S14). As a result, the distance chart 41 emits the light beam of the visual acuity measurement target 45a that it had emitted immediately before (before switching to the position adjustment mode), and the target presenting optical system 5 presents the immediately preceding test screen to the subject's eye E through the target presenting window W (step S15).

[0103] Thereafter, the processes from step S4 to step S15 are repeatedly executed until the distance vision test is completed. Although not shown in the drawings, the type (visual acuity value) of the visual target 45a for vision measurement presented to the subject's eye E is also changed as appropriate.

[0104] FIG. 14 is a flowchart showing the flow of a distance vision test other than a distance visual acuity test using the optotype presenting device 2 configured as described above.

[0105] 14, when the examiner operates the operation unit 8A to start a distance test other than a distance visual acuity test (e.g., a red-green test) (step S1A), the display control unit 70 operates the distance chart 41 in a test mode. Then, the distance chart 41 emits a light beam of a target chart (such as the red-green test target chart 46A, the radiation chart 46B, or the point cloud chart 46C in FIG. 6) corresponding to the type of distance test selected by the operation unit 8A. As a result, the target chart selected by the examiner is presented to the subject's eye E through the target presenting window W by the target presenting optical system 5 (step S2A).

[0106] Thereafter, the processing of steps S3 and S4 is executed in the same manner as in the distance vision test shown in Figure 13 described above, and the photographing of face F by the second photographing unit 62, the acquisition of the photographed image of face F by the photographed image acquisition unit 72, and the detection of the positions of the subject's eye E and face F by the position detection unit 73 are repeatedly executed.

[0107] At this time, the determination unit 74 checks the visual acuity value of the visual acuity measurement optotype 45a last presented to the subject's eye E (step S5A), and selects the testable range R corresponding to this visual acuity value from the first testable range R1 to the third testable range R3 (step S5B). Then, the determination unit 74 determines whether the subject's eye E is included in the selected testable range R based on the position detection result newly input from the position detection unit 73 (step S6A). This makes it possible to determine whether the subject's eye E is included in the testable range R corresponding to the visual acuity value of the subject's eye E even while a test target (test target chart) other than the visual acuity measurement optotype 45a is being presented.

[0108] The processing from step S6A onwards is the same as that in the distance vision test shown in FIG. 13, and therefore a detailed description thereof will be omitted here.

[0109] As described above, the optotype presenting device 2 of this embodiment repeatedly detects the positions of the subject's eye E and face F, repeatedly determines whether the subject's eye E is included in the testable range R based on the position detection results, and presents the notification image 76 to the subject's eye E if the subject's eye E is not included in the testable range R. This notifies the subject J that the subject's eye E is not included in the testable range R, and urges the subject J to adjust the position of his or her face F. Having the subject J adjust the position of his or her face F eliminates the need to provide a movement mechanism for moving the housing 3 or the optical system within the housing 3. As a result, the optotype presenting device 2 of this embodiment can prevent the subject's eye E from shifting from the testable range R in a space-saving and low-cost manner.

[0110] [others] In the above embodiment, the face image 80 generated from a photographed image of the face F is used as an image indicating the position of the subject's eye E (face F) in the notification image 76, but various images such as a two-dimensional or three-dimensional face model (eyes only is also acceptable), a face illustration image (eyes only is also acceptable), a character image, or a mark indicating the position of the face F (subject's eye E) may be used instead. Furthermore, the range images 82A to 82C are not limited to the images shown in Figures 7 to 12 and can be changed as appropriate.

[0111] In the above embodiment, during a distance vision test of the subject eye E, the positions of the subject eye E and face F are detected, a determination is made as to whether the subject eye E is included in the testable range R, and an alarm image 76 is presented to the subject eye E if the subject eye E is not included in the testable range R, but these processes may also be performed during a near vision test of the subject eye E. [Explanation of symbols]

[0112] 2...Visual target presentation device 3. Housing 5...Optic target presentation optical system 7...Control device 8A…Operation unit 8B…Display section 9...Ophthalmology table 31...Caster 41...Distance visual chart 42…Near visual chart 43…Near vision table movement part 45…Visual acuity chart 45a...Optotype for visual acuity measurement 46A...Red-Green Test Optotype Chart 46B...Radiation chart 46C...Point Cloud Chart 51...First reflecting mirror 52...Convex lens system 53...Second reflecting mirror 54...Second reflecting mirror driving section 61...First Filming Section 62...Second Filming Section 64...Infrared light source 70...Display control unit 71...imaging control unit 72...Image acquisition unit 73...Position detection unit 74…Judgment section 75...Notification image generation unit 76...Notification image 76A...First notification image 76B...Second notification image 76C...Third notification image 80...Facial image 82A, 82B, 82C...Area images 84...Warning message 85...Completion message 91...post 92...Refractor Head 93...Lighting unit 411, 421...display screen 521…Focus 531…Far-view presentation position E: Eye to be examined F...face J…Subject LA1, LA2…optical axis R: Inspection range R1: First inspection range R2: Second inspection range R3: Third inspection range W: Optotype presentation window

Claims

1. a display device that emits a target light beam of one or more targets for testing the subject's eye; A target presentation window; an optotype presenting optical system that guides the optotype light beam emitted from the display device to the optotype presenting window and presents the optotype to the subject's eye through the optotype presenting window; a position acquisition unit that repeatedly acquires the position of at least the subject's eye; a determination unit that determines whether the subject's eye is included in a predetermined testable range based on the position of the subject's eye acquired by the position acquisition unit each time the position acquisition unit acquires the position of the subject's eye; and a display control unit that switches the display device to an examination mode in which the visual target light beam is emitted when the determination unit determines that the eye to be examined is included in the testable range, and switches the display device to a position adjustment mode in which the visual target light beam is emitted when the determination unit determines that the eye to be examined is not included in the testable range, and Equipped with An optotype presenting device in which the optotype presenting optical system guides the light beam of the notification image emitted from the display device in the position adjustment mode to the optotype presenting window and presents the notification image to the subject's eye through the optotype presenting window.

2. The target presentation device of claim 1, wherein if the judgment unit judges that the test eye is not included in the testable range, the position acquisition unit acquires the position of the test eye, the judgment unit makes a judgment, and the display device emits a light beam of the notification image, until the judgment unit determines that the test eye is included in the testable range.

3. the optotype is a first optotype for measuring visual acuity, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are determined in advance, 2. The optotype presenting device according to claim 1, wherein the determination unit determines whether the subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype being presented to the subject's eye.

4. the visual target includes the first visual target and a second visual target for testing that is different from the first visual target, 4. The optotype presenting device according to claim 3, wherein the determination unit, while presenting the second optotype to the test eye, determines whether the test eye is included in the testable range corresponding to the visual acuity value of the first optotype last presented to the test eye.

5. and an alert image generating unit configured to generate the alert image including a first image indicating the position of the subject's eye and a second image indicating the testable range based on the position of the subject's eye newly acquired by the position acquiring unit each time the position acquiring unit acquires a new position of the subject's eye when the determining unit determines that the test is not possible, 2. The target presenting device according to claim 1, wherein the display device in the position adjustment mode emits a light beam of the newly generated notification image by the notification image generating unit each time the notification image is generated by the notification image generating unit.

6. the optotype is a first optotype for measuring visual acuity, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are determined in advance, the determination unit determines whether the subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype being presented to the subject's eye, When the determination unit determines that the first optotype is not present to the subject's eye while the first optotype is being presented, the notification image generation unit displays the testable range corresponding to the visual acuity value of the first optotype being presented. The visual target presenting device according to claim 5 , wherein the second image is generated by:

7. the visual target includes the first visual target and a second visual target for a test other than visual acuity measurement, the determination unit determines, during presentation of the second optotype to the subject's eye, whether or not the subject's eye is included in the testable range corresponding to the visual acuity value of the first optotype last presented to the subject's eye; 7. The optotype presenting device according to claim 6, wherein, when the judgment unit judges that the second optotype is not present to the subject's eye, the notification image generating unit generates the second image indicating the testable range corresponding to the visual acuity value of the first optotype last presented to the subject's eye.

8. The position acquisition unit an imaging unit that captures an image of the subject's face; a position detection unit that detects the position of at least the subject's eye based on the captured image captured by the imaging unit; Equipped with The optotype presenting device according to claim 5 , wherein the notification image generating section generates a facial image of the subject as the first image based on the captured image captured by the capturing section.

9. the optotype is a first optotype for measuring visual acuity, a plurality of testable ranges having different sizes depending on the visual acuity value of the first optotype are determined in advance, the position detection unit detects the position of the subject's eye and the position of the subject's face, Among the plurality of testable ranges, the testable range corresponding to the specific testable target, which is the first testable target having a visual acuity value equal to or less than a predetermined visual acuity value, indicates an allowable range of the position of the face, the determination unit determines whether the subject's eye is included in the testable range based on a position detection result of the position detection unit while the specific target is being presented to the subject's eye, depending on whether the face is included in the allowable range; 9. The optotype presenting device according to claim 8, wherein the notification image generating unit generates the second image indicating the tolerance range when the determining unit determines that the specific optotype is not acceptable while the specific optotype is being presented to the subject's eye.

10. A visual target presenting device as described in any one of claims 5 to 7, wherein when the display device is in the position adjustment mode and the judgment unit determines that the test eye is included in the testable range, the notification image generation unit changes the display mode of the second image, and then the display control unit switches the display device to the test mode.

Images