Target presentation device

Abstract

To provide a target presentation device that improves inspection efficiency when distant vision inspection and near vision inspection are performed.SOLUTION: A target presentation device includes: a first target display part (first display 36) that presents a target at a first distance with respect to a subject eye e; a second target display part (second display 37) that presents a target at a second distance different from the first distance; and a housing 31 provided with a target presentation window 32. A distance from the subject eye e to the target presentation window 32 is shorter than the second distance, and the first target display part and the second target display part are arranged inside the same housing 31.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an optotype presentation device used in ophthalmic examinations. [Background technology]

[0002] Subjective optometry devices have been known that present a visual target to the subject and test the visual function of the subject's eye based on the subject's response. Subjective optometry tests include a distance test in which a visual target is presented approximately 5 m in front of the subject's eye, and a near test in which a visual target is presented 30 to 40 cm in front of the subject, which is the near visual distance, to test the subject's ability to accommodate. Near tests are often performed on elderly people whose ability to accommodate may be declining due to aging or other factors.

[0003] A common near vision test is an ophthalmic device equipped with a near vision target plate suspended from a near point rod attached to a refractor head (see, for example, Patent Document 1). In this ophthalmic device, the near vision target plate is presented by hanging it down in front of the line of sight of the subject's eye. On the other hand, when a distance test is performed, the near vision target plate is retracted from the line of sight.

[0004] There is also an optometry device that uses a single optotype presentation unit to switch between presenting optotypes for a distance test and a near test by changing the orientation of the optotype presentation unit disposed in a housing (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-049220 [Patent Document 2] Japanese Patent Application Publication No. 2019-177096 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the above-mentioned conventional technology, it is not possible to achieve both the state for distance testing and the state for near testing at the same time, so it takes time and effort to insert, remove, and move the targets for distance and near, leaving room for improvement in terms of testing efficiency.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to further improve the efficiency of examinations when conducting distance and near vision tests on a subject's eye. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the ophthalmic device of the present disclosure comprises a first optotype display unit that presents an optotype at a first distance to the subject's eye, a second optotype display unit that presents the optotype at a second distance different from the first distance, and a housing provided with an optotype presentation window, wherein the distance from the subject's eye to the optotype presentation window is shorter than the second distance, and the first optotype display unit and the second optotype display unit are arranged in the same housing.

[0009] The first distance is a distance examination distance, and the second distance is a near examination distance. The eye examination device may further include a display control unit that controls the first optotype display unit and the second optotype display unit, a first drive unit that moves the second optotype display unit in a direction parallel to the display surface, and a first drive control unit that controls the first drive unit, wherein the first drive unit can stop the second optotype display unit at at least two positions within its movement range under the control of the first drive control unit, and the display control unit can switch between displaying and hiding the first optotype display unit and the second optotype display unit at the stop positions. [Effects of the Invention]

[0010] By configuring it in this way, when presenting the near vision target, the far vision target light beam is not blocked and the target is presented at a different position up or down, eliminating the need for switching time and further improving the efficiency of the test when conducting the far vision test and the near vision test. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing the appearance of an ophthalmologic apparatus according to a first embodiment. [Figure 2] 1 is a cross-sectional view showing the internal arrangement of a visual target presentation device according to Example 1. FIG. [Figure 3A] FIG. 10 is a diagram showing the position of the second display during near vision optometry according to Example 1. [Figure 3B] FIG. 10 is a diagram showing the position of the second display during near vision optometry according to Example 1. [Figure 4] FIG. 10 is a diagram showing the position of the second display during distance optometry according to the first embodiment. [Figure 5] FIG. 10 is a diagram showing the position of the second display when near and far targets are simultaneously presented according to Example 2. [Figure 6] 10 is a diagram showing the relationship between the eye height of a subject and an eye height adjusting mirror according to Example 2. FIG. [Figure 7A] FIG. 10 is a diagram showing the positions of a distance target and a near target depending on the height of the near target according to Example 2. [Figure 7B] FIG. 10 is a diagram showing the positions of a distance target and a near target depending on the height of the near target according to Example 2. [Figure 7C] FIG. 10 is a diagram showing the positions of a distance target and a near target depending on the height of the near target according to Example 2. [Figure 8A] 10 is a diagram showing the eye height of the subject's eye and the position of the second display according to Example 2. FIG. [Figure 8B] 10 is a diagram showing the eye height of the subject's eye and the position of the second display according to Example 2. FIG. [Figure 9A] FIG. 10 is a diagram showing the field of view of the refractor head and the position of the second display according to Example 3. [Figure 9B] FIG. 10 is a diagram showing the field of view of the refractor head and the position of the second display according to Example 3. [Figure 10] FIG. 10 is a diagram showing a configuration for horizontally moving a second display according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Example 1 Hereinafter, an ophthalmic apparatus according to the present disclosure and an optotype presenting device included in the ophthalmic apparatus will be described with reference to the accompanying drawings.

[0013] The configuration of an ophthalmic apparatus 100 according to the first embodiment will be described with reference to Figures 1 and 2. The ophthalmic apparatus 100 is an ophthalmic apparatus capable of measuring the ocular characteristics of the subject's eye based on the subject's response.

[0014] As shown in FIG. 1, the ophthalmologic apparatus 100 includes an eye examination table 1, a refractor head 2, a visual target presenting device 3, and a controller 4 which is a control device.

[0015] Throughout this specification, the X-axis, Y-axis, and Z-axis are defined as shown in FIG. 1, and when facing the visual target presentation device 3, the left-right direction is defined as the X-direction, the up-down direction is defined as the Y-direction, and the front-back direction (depth direction) perpendicular to the X-direction and Y-direction is defined as the Z-direction.

[0016] The optometry table 1 has various devices placed on it, such as a refractor head 2, a visual target presentation device 3, and a controller 4. It is also used as a table on which the examinee places their hands and arms to stabilize their posture during the eye examination. The height of the table 11 can be adjusted to suit the examinee's physique by moving it up and down (Y direction) using a motor built into the legs 12.

[0017] The refractor head 2 is an ophthalmic device used to determine the ocular characteristics of the subject's eye by selecting and placing a lens capable of correcting the subject's eye and an optical element for performing an examination to determine the correction value in front of the subject's eye. As shown in Figure 1, the refractor head 2 includes a support mechanism 21 and a pair of eye examination units 22 corresponding to the subject's left and right eyes.

[0018] The subject responds to how the visual target presented on the visual target presentation device 3 appears via the optical elements in the eye examination unit 22, and the subject's eye characteristics are determined based on the results of the response for the selected combination of optical elements.

[0019] The refractor head 2 can be moved in the Y-axis direction to suit the subject's physique by hanging it from a support post 23 that can be extended and retracted up and down and a support arm 24 that can be rotated around the support post 23. At the same time, the refractor head 2 can be rotated and moved away from in front of the subject's face, allowing the visual target to be presented without using the refractor head 2.

[0020] The visual target presentation device 3 is used to present a visual target for testing to a subject. As shown in Fig. 2, the visual target presentation device 3 has an optical system for presenting a visual target inside a box-shaped housing 31, and a visual target presentation window 32 for visually viewing the visual target is provided on the front surface of the housing 31.

[0021] The optical system inside the housing 31 of the optotype presentation device 3 includes a first display 36, which is a first optotype display unit, a reflecting mirror 35, and a lens 34. The first display 36 is composed of an electronic display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. Based on a control signal from the controller 4, the first display 36 displays an optotype for distance optometry on its display surface 36a.

[0022] A light beam from the first display 36 passes along the optical axis L, is reflected by the reflecting mirror 35, and is then refracted by the lens 34 to form a virtual image of the target image i. The light beam is reflected and deflected by the eye-height adjusting mirror 33, which is a reflecting member, and heads toward the target presenting window 32. The subject's eye e can view the target image i through the target presenting window 32 and the refractor head 2 along the distance target optical axis L' reflected and deflected by the eye-height adjusting mirror 33. Here, the target image i is positioned at a distance examination distance, for example, 5 m, from the subject's eye e.

[0023] The eye-height adjusting mirror 33 can change its tilt angle using a second drive unit and also functions as a height adjustment mechanism. The eye-height adjusting mirror 33 aligns the optical axis L from the first display 36 with the distance target optical axis L' of the subject's eye e and the target image i by changing the tilt angle. In other words, by adjusting the tilt angle according to the height position of the subject's eye e, the target image i can be presented appropriately to each subject's eye e, even if the height of the subject's eye e varies depending on the subject's physique, etc.

[0024] The second display 37, which is the second optotype display unit, is disposed inside the housing 31 at a near-distance optometry distance from the subject's eye e. The second display 37 is configured with an electronic display device such as an LCD or organic EL display, similar to the first display 36, and displays an optotype for near-distance optometry on its display surface 37a based on a control signal from the controller 4.

[0025] The near examination distance is the distance at which the subject views a nearby object, and falls within a range of approximately 25 cm to 40 cm. Here, it is set to 40 cm. The second display 37 can be moved substantially parallel to the display surface 37a by the first drive unit. The first drive unit moves the second display 37 based on a control signal from the controller 4. In Example 1, the display surface 37a of the second display 37 is disposed substantially parallel to the optotype presentation window 32, and moves in the Y direction, i.e., the up and down direction.

[0026] Although the details of the movement mechanism and drive method are not shown, common movement and drive methods are used. The movement range is from the position where the center of the display surface 37a of the second display 37 intersects with the distance target optical axis L' in the upper direction to the position where the entire second display 37 is hidden below the target presenting window 32 in the lower direction. The movement range is not necessarily limited to this, and the second display 37 may move up to above the distance target optical axis L', or may remain within the target presenting window 32 in the lower direction.

[0027] The controller 4 includes an arithmetic circuit configured with various processors, memories, etc. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), and a field programmable gate array (FPGA) that is a programmable logic device. The various functions of the controller 4 may be realized by a single processor, or may be realized by multiple processors of the same or different types.

[0028] The controller 4 functions as a display control unit and a determination unit by reading and executing a control program (not shown). The controller 4 also has the function of a drive control unit that controls a first drive unit that drives the second display 37 and a second drive unit that drives the eye height adjustment mirror 33.

[0029] The display control unit controls the visual targets displayed on the first display 36 and the second display 37. It transmits a control signal to the first display 36 or the second display 37 to display the visual target specified by the controller 4. It also controls the display and non-display of each display.

[0030] The determination unit determines whether the refractor head 2 or the glasses are used for the examination.

[0031] The drive control unit transmits a control signal to the first drive unit to drive the second display 37 substantially parallel to the display surface 37a. The second display 37 stops at a plurality of positions, such as a position where it blocks the light beam from the first display 36, a position above the opening of the optotype presentation window 32 but does not block the light beam from the first display 36, and a position below the opening of the optotype presentation window 32.

[0032] The drive control unit also sends a drive control signal to a second drive unit that changes the tilt angle of the eye height adjustment mirror 33. If the eye e to be examined is higher than the reference, the tilt angle is adjusted upward, and if the eye e is lower than the reference, the tilt angle is adjusted downward.

[0033] As shown in Fig. 3A, the state in which the second display 37 is moved upward by the first drive unit corresponds to the near vision optometry state. Here, a near vision optometry target is displayed on the display surface 37a of the second display 37 in response to a control signal from the display control unit, and the first display 36 is hidden under control of the display control unit. The subject P visually views the target on the second display 37 presented at the near vision optometry distance and responds regarding how the target appears, thereby testing the eye characteristics at the near vision distance.

[0034] In this state, the second display 37 is positioned substantially in front of the subject's eye e, but as shown in Fig. 3B, if the second display 37 is lowered to present a target, the subject P will assume a downward posture, enabling near vision examination in a state closer to natural vision. At this time, the refractor head 2 may be tilted.

[0035] When performing distance optometry, the second display 37 is hidden as shown in Fig. 4. Furthermore, the first drive unit moves the second display 37 below the optotype presenting window 32, and the first display 36 (not shown) is displayed to present the distance optotype, thereby enabling distance optometry. At this time, the second display 37 is in a state where it does not block the light beam from the first display 36, and therefore does not interfere with distance optometry.

[0036] Furthermore, by using the first drive unit to move the second display 37 below the optotype presentation window 32 and making it invisible to the subject P, the accommodative stimulus caused by a near object is reduced, enabling more accurate distance optometry. The accommodative stimulus is when an object is present in the near field of view during distance optometry, and accommodation occurs to see the object, which affects distance optometry. Therefore, it is desirable to have no unnecessary objects in the field of view during distance optometry.

[0037] Example 2 The configuration of the device in Example 2 is the same as that in Example 1. In Example 1, the second display 37 must be moved to perform distance and near vision optometry separately, and switching between them takes time. On the other hand, in Example 2, as shown in Figure 5, the second display 37 is moved downward compared to the near vision optometry state in Example 1, and a near vision target is presented.

[0038] The term "lower" refers to a position that does not block the light beam from the first display 36, and is outside the visual angle w at which the subject's eye e views the optotype image i. Here, a distance optotype is displayed on the first display 36 (not shown), and a near optotype is simultaneously displayed on the second display 37. This allows both distance and near optotypes to be presented simultaneously, and the subject can view either the distance or near optotype simply by shifting his or her line of sight, eliminating the need for time spent moving the second display 37. This allows for faster eye examinations and improved testing efficiency.

[0039] Therefore, unlike normal distance and near vision optometry, it is also possible to test the time required for the subject's eye to adjust from distance to near vision. When performing only distance vision optometry without performing near vision optometry, it is desirable to retract the second display 37 below the region of the optotype presenting window 32, as in the first embodiment.

[0040] When a near target is presented below a distance target, it is desirable that the second display 37 does not block the light beam from the target image i and is located close to the target image i. In particular, when eye examination is performed via the refractor head 2, the viewing angle of the refractor head 2 is limited, and if the angle of view becomes large relative to the optical axis of the lens in the refractor head 2, the eye examination is susceptible to the effects of aberration, which may prevent correct eye examination.

[0041] Since the eye height of the subject P varies depending on the subject's height and sitting height, it is necessary to adjust the height of the refractor head 2 to the eye height of the subject P, and accordingly, the height of the visual target presentation device 3 must also be adjusted accordingly. This can be done by adjusting the table 11 on which the visual target presentation device 3 is placed up and down, or by rotating the eye height adjustment mirror 33 inside the visual target presentation device 3 to change the reflection angle.

[0042] As shown in Figure 6, for subject P1 with average eye height, the eye-height adjustment mirror 33 is positioned at 45°, and the light beam is deflected by 90° before reaching the subject's eye e1. On the other hand, for subject P2 with high eye height, the eye-height adjustment mirror 33 is rotated and tilted upward to the angle of the eye-height adjustment mirror 33', which changes the reflection angle of the light beam and causes it to reach subject's eye e2, which is higher than subject's eye e1. For subjects with low eye height, the eye-height adjustment mirror 33 can be tilted downward (not shown) to present an optimal optotype for each subject's eye height.

[0043] Here, when simultaneous near and far vision optometry is performed by positioning the second display 37 in accordance with the subject's eye e1 having an average eye height, it is desirable that the second display 37 be positioned close to the optotype image i without blocking the far vision optotype light beam, as described above. In Fig. 8A, the distance from the center of the visual angle of the subject's eye e1 having an average eye height to the center of the second display 37 is length h. In this state, by positioning the second display 37 close to but not blocking the far vision light beam as shown in Fig. 8A, the far vision optotype image i (first display 36) and the near vision optotype (second display 37) are positioned close to each other as shown in Fig. 7A, and do not block the optotype image i.

[0044] On the other hand, if the eye-height adjusting mirror 33 is adjusted to fit the subject's eye e2, which has a high eye height, without changing the position of the second display 37, the subject's eye e2 will be looking down at the distance target image i', as shown in Fig. 8A. This creates a gap between the visual angle w' and the second display 37, and as shown in Fig. 7B, a gap will be created between the distance target image i and the near target for the subject P2.

[0045] As shown in Figure 8B, when the position of the second display 37 is driven upward from length h to length h', there is almost no gap between the visual angle w' of the subject's eye e2 and the second display 37, and the target image i and the near target become close to each other as shown in Figure 7A.

[0046] Conversely, if the height of the second display 37 is adjusted to match the eye e2, which has a high eye height, the lower part of the distance target light beam will be blocked when viewed from the eye e1, as shown in Fig. 7C. Therefore, it is desirable to change the height of the second display 37 according to the height of the eye e, in other words, according to the angle of the eye height adjustment mirror 33.

[0047] When the angle between the eye-height adjustment mirror 33 and the optical axis L becomes smaller than 45° (when the eye-height adjustment mirror 33 is tilted upward), the position of the second display 37 is raised from when it was at 45°. On the other hand, when the angle between the eye-height adjustment mirror 33 and the optical axis L becomes larger than 45° (when the eye-height adjustment mirror 33 is tilted downward), it is desirable to lower the position of the second display 37 from when it was at 45°.

[0048] The visual target presentation device 3 detects the eye height of the subject's eye e and changes the angle of the eye height adjustment mirror 33 using the second drive unit. The second display 37 controls the vertical stop position based on the obtained eye height information. Methods for detecting eye height include detecting light emitted from a remote control placed at the height of the subject's eye based on the output from a light sensor installed in the main body of the visual target presentation device 3, and using a means for detecting height information from the refractor head 2.

[0049] Example 3 When the near and far targets are simultaneously presented and the eye examination is performed via the refractor head 2, it is desirable that the second display 37 is positioned close to the far target light beam and does not block it.

[0050] On the other hand, when checking with eyeglasses prescribed with progressive power trial lenses or progressive power lenses, it is desirable to check while visually viewing the near vision target through the portion prescribed as the near vision zone of the eyeglass lens. Since the near vision zone is generally prescribed lower than the distance vision zone, if the near vision target is placed directly below and close to the distance vision target as described above, the line of sight when visually viewing the near vision target will not pass through the near vision zone of the eyeglass lens. As a result, the prescribed performance cannot be fully obtained.

[0051] In Example 3, the controller 4 selects whether to use the refractor head 2 as shown in Fig. 9A or to use glasses as shown in Fig. 9B, and the selection is judged by the judgment unit. If the judgment unit judges that glasses have been selected, the second display 37 is presented at a lower position than when the refractor head 2 is used for eye examination.

[0052] The amount by which the second display 37 is lowered may be determined according to the type of eyeglass lens input to the controller 4, or the amount of lowering may be input as a numerical value. Furthermore, the determination of switching between the refractor head 2 and the eyeglass lens is not limited to an input from the controller 4, and switching may be performed automatically depending on whether the refractor head 2 is stored in the retracted position.

[0053] Example 4 10, the second display 37 is disposed between the eye-height adjusting mirror 33 and the lens 34, and the display surface 37a of the second display 37 faces upward. The light beam from the second display 37 is reflected and deflected by the eye-height adjusting mirror 33, passes through the optotype presenting window 32, and reaches the subject's eye e. The second display 37 is disposed so that the distance from the subject's eye e to the display surface 37a is the near examination distance.

[0054] In Example 4, the distance from the optotype presentation window 32 to the display surface 37a of the second display 37 can be made longer within the housing of the optotype presentation device 3, so the subject can get closer to the optotype presentation window 32, making it possible to perform eye examinations in a more space-saving manner.

[0055] The second display 37 is configured to be movable in the Z direction, i.e., the front-to-back direction, by a first drive unit with the display surface 37a facing upward. It is moved to the optical axis L to perform near vision examination, and when performing distance vision examination, it is retracted to a position where it does not block the light beam from the first display 36.

[0056] When presenting a distance target and a near target simultaneously, the second display 37 is moved forward from the center of the optical axis of the lens 34. By moving it to a position far from the subject's eye where it does not block the distance light beam, the distance target and the near target can be presented simultaneously. [Explanation of symbols]

[0057] 1 optometry table 2 Refractor Head 3 Visual target presentation device 4 Controllers 11 tables 12 Legs 21 Support mechanism 22 Optometry Unit 23 Pillar 24 Support arm 31 Case 32 Visual target presentation window 33 Eye-height adjustable mirror 34 Lens 35 Reflective mirror 36 1st display 36a Display surface of first display 37 Second Display 37a Display surface of second display 100 Ophthalmology equipment e. Examined eye i optotype image L optical axis L' Distance target optical axis

Claims

1. a first optotype display unit that presents an optotype at a first distance to the subject's eye; a second optotype display unit that presents an optotype at a second distance different from the first distance; a housing provided with a target presentation window; a distance from the subject's eye to the optotype presentation window is shorter than the second distance, and the first optotype display unit and the second optotype display unit are arranged in the same housing.

2. 2. The visual target presenting device according to claim 1, wherein the first distance is a distance examination distance, and the second distance is a near examination distance.

3. a display control unit that controls the first optotype display unit and the second optotype display unit; a first drive unit that moves the second optotype display unit in a direction parallel to a display surface; a first drive control unit for controlling the first drive unit, the first drive unit is capable of stopping the second optotype display unit at at least two positions within a movement range under the control of the first drive control unit, The display control unit can switch between displaying and hiding the first optotype display unit and the second optotype display unit at the stop position. The visual target presentation device according to claim 2 .

4. The stop position of the second optotype display unit is a position that blocks the light beam from the first optotype display unit; a position above the opening of the optotype presentation window and not blocking the light beam from the first optotype display unit; a position below the opening of the optotype presentation window. The visual target presentation device according to claim 3 .

5. a reflecting member for deflecting a light beam from the first optotype display unit is provided in the housing; a second driving unit that changes the angle of the reflecting member; a second drive control unit for controlling the second drive unit, The second target display unit can be driven up and down depending on the angle of the reflecting member. The visual target presentation device according to claim 2 or 3.

Images