Calibration device of vision screening instrument

Abstract

The utility model provides a calibration device for a vision screening instrument. The calibration device comprises a lens cone and a lens which is arranged in the lens cone and is coaxial with the lens cone, wherein the lens is arranged at one end of the lens barrel, a reflector is arranged at one end, far away from the lens, of the lens barrel, and one side, close to the lens, of the reflector is an arc-shaped concave surface; the device further comprises a degree calibration assembly which is used for providing different calibration degrees. The lens simulates the crystalline lens of the human eye, the reflector simulates the retina of the human eye, the degree calibration assembly is adjusted, the degree calibration assembly is set to a certain degree, the vision screening instrument emits light, and the vision screening instrument is calibrated according to the imaging condition of the light on the reflector after the light penetrates through the degree calibration assembly and the lens. The degree calibration adjustment is simple, and the operation is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to visual screening field, especially a visual screening instrument calibration device. BACKGROUND

[0002] Visual screening instrument is a kind of instrument and equipment that can quickly, objectively detect the refractive state of eye and other vision-related indicators to screen out vision abnormality, and it needs to be calibrated before leaving factory.The main purpose of calibration is to determine the input-output relationship of instrument or measuring system, give instrument or measuring system graduation value;Determine the static characteristic index of instrument or measuring system: eliminate system error, improve the accuracy of instrument or system.

[0003] The calibration device commonly seen on market currently has fixed calibration degree, and special calibration degree needs to be customized, so the application range is small, and the customization process is cumbersome and high in cost. UTILITY MODEL CONTENT

[0004] The utility model aims at the defects in the above-mentioned technology, provides a visual screening instrument calibration device, and degree calibration adjustment is simple, convenient operation.

[0005] The utility model aims at the defects in the above-mentioned technology, provides a visual screening instrument calibration device, and degree calibration adjustment is simple, convenient operation.

[0006] The lens is arranged at one end of the lens barrel, one end of the lens barrel away from the lens is provided with a reflector, and the side of the reflector close to the lens is arc-shaped concave;

[0007] Further comprising degree calibration assembly, and the degree calibration assembly is used to provide different calibration degrees.

[0008] In the above scheme, the lens simulates the lens of human eye, the reflector simulates the retina of human eye, the degree calibration assembly only needs to be adjusted, the degree calibration assembly is set to a certain degree, the visual screening instrument emits light, and the visual screening instrument is calibrated according to the imaging condition of light passing through the degree calibration assembly and the lens on the reflector, the degree calibration adjustment is simple and convenient to operate.

[0009] In some possible implementation manners, the degree calibration assembly comprises a lens barrel;

[0010] The lens barrel comprises a first barrel body and a second barrel body, and the first barrel body and the second barrel body are slidingly sleeved;

[0011] The lens is arranged at one end of the lens barrel away from the second barrel body, and the reflector is arranged at one end of the second barrel body away from the first barrel body.

[0012] In some possible implementation manners, the lens barrel further comprises a distance calibration device, and the distance calibration device comprises an indicating block and a scale, which are arranged on the first barrel body and the second barrel body respectively.

[0013] In some possible implementation manners, a sealing ring is arranged between the first barrel body and the second barrel body.

[0014] In some possible implementation manners, the diopter calibration assembly comprises a connecting block and a plug-in lens sheet clamped with the connecting block.

[0015] The connecting block is connected with the lens barrel and arranged on the side of the lens away from the light-reflecting sheet.

[0016] In some possible implementation manners, the connecting block is provided with at least one clamping groove.

[0017] In some possible implementation manners, the number of the clamping grooves is three.

[0018] In some possible implementation manners, an axial position scale is further arranged between the connecting block and the lens barrel, and the axial position scale is coaxially arranged with the lens barrel and used for calibrating the astigmatism direction.

[0019] In some possible implementation manners, a pupil simulation assembly is further included, and the pupil simulation assembly comprises a plug-in plate, and the plug-in plate is eccentrically and rotatably connected with the lens barrel through a rotating shaft.

[0020] The plug-in plate is arranged on the side of the lens away from the light-reflecting sheet, and the plug-in plate is coaxially provided with a plurality of round holes around the rotating shaft.

[0021] In some possible implementation manners, a base is further included, and a supporting rod is rotatably connected above the base, and the supporting rod is fixedly connected with the lens barrel. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a three-dimensional structure schematic view of a vision screening instrument calibration device of the utility model;

[0023] Figure 2 is a structure schematic view of a vision screening instrument calibration device of the utility model Figure 1 ;

[0024] Figure 3 is a structure schematic view of a vision screening instrument calibration device of the utility model Figure 2 ;

[0025] Figure 4 is a structure schematic view of a vision screening instrument calibration device of the utility model Figure 3 ;

[0026] Figure 1 is a sectional view structure schematic diagram of the visual acuity screening instrument calibration device. DETAILED DESCRIPTION

[0027] The application provides a visual acuity screening instrument calibration device, which simulates the lens of a human eye through a lens and simulates the retina of a human eye through a reflecting sheet; only the power calibration assembly needs to be adjusted; after the power calibration assembly is set to a certain power, the visual acuity screening instrument emits light, and the visual acuity screening instrument is calibrated according to the imaging condition of the light on the reflecting sheet after the light passes through the power calibration assembly and the lens; the power calibration adjustment is simple and convenient to operate. The problem of fixed calibration power of the calibration device of the visual acuity screening instrument in the prior art and small application range is solved.

[0028] In order to facilitate understanding of the technical scheme of the application, the application scenarios are described below:

[0029] The visual acuity screening instrument is based on the optical principle, enters the eyes through emitting specific light, receives reflected light and analyzes the eye refraction state information carried by the reflected light, and then combines the image analysis technology to infer the degree and type of ametropia. The eye image is shot in a certain distance, the difference between light and dark caused by different degrees of image display based on the abnormal refraction of the human eye, and the index reflecting the refraction state is obtained through measurement and operation, which is an objective refraction method.

[0030] The embodiment will be further described below with reference to the drawings:

[0031] From Figure 5 - Figure 5 It can be known that the application provides a visual acuity screening instrument calibration device, which comprises a lens barrel 1 and a lens 2 coaxially arranged in the lens barrel 1. The lens 2 is arranged at one end of the lens barrel 1, and a reflecting sheet 3 is arranged at the end of the lens barrel 1 away from the lens 2. The side of the reflecting sheet 3 close to the lens 2 is arc-shaped and concave.

[0032] It should be noted that the lens 2 in the application is equivalent to the lens of a human eye, which is a 20D spherical mirror. According to the formula diopter D = 1 / f, where f is the focal length with the unit of meters (m), the focal length of the spherical mirror can be determined as 0.05 m. Therefore, when the reflecting sheet 3 is at a distance of 0.05 m from the center of the lens 2, the calibration device is equivalent to 0 power, that is, the eye has no myopia or hypermetropia. Wherein, “D” represents diopter (English name dioptre) and is also the unit of diopter. Diopter is the unit of dioptric power, represented by D, that is, the dioptric power of the parallel light passing through the dioptric substance (such as a lens or a human eye lens) is 1 diopter or 1D when the focal point is at 1 m, and the focal length of the lens is 0.5 m. The dioptric power is 2D.

[0033] The diopter of the convex lens is indicated by a "+" sign, for example, +1.0D represents a convex lens with a focal length of 1m; the diopter of the concave lens is indicated by a "-" sign, for example, -2.0D represents a concave lens with a focal length of 0.5m.

[0034] As an example, the lens 2 of the calibration device in the present application can be a convex lens with a diopter of +20D, so the focal length is at a position of 0.05m, that is, when the reflecting sheet 3 is at a distance of 0.05m from the lens 2, the calibration device is equivalent to a human eye with 0 degrees, without diopter.

[0035] The reflecting sheet 3 in the present application is equivalent to the retina of the human eye, and the side close to the lens 2 of the reflecting sheet 3 is an arc-shaped concave surface, the shape of which imitates the shape of the human eye retina.

[0036] It should be understood that the infrared light emitted by the vision screening instrument in the present application passes through the lens 2, is reflected and imaged, and returns to the vision screening instrument. In order to realize the calibration of the vision screening instrument, the present application also provides a degree calibration assembly, which is arranged in the optical path between the vision screening instrument and the reflecting sheet 3, and the vision screening instrument is calibrated by providing different calibration degrees through the degree calibration assembly.

[0037] Specifically, a certain degree is provided through the degree calibration assembly of the calibration device, the vision screening instrument is optometryed on the calibration device, and it is judged whether there is an error between the optometry result of the vision screening instrument and the degree provided by the calibration device. If the error is within a reasonable range, it is considered that the vision screening instrument is in a normal working state; if the error exceeds the reasonable error value, the vision screening instrument is adjusted.

[0038] In the above scheme, the lens 2 simulates the human eye lens, and the reflecting sheet 3 simulates the human eye retina, and only the degree calibration assembly needs to be adjusted. After the degree calibration assembly is set to a certain degree, the vision screening instrument emits light, and the vision screening instrument is calibrated according to the imaging condition of the light passing through the degree calibration assembly and the lens 2 on the reflecting sheet 3. The degree calibration adjustment is simple and convenient to operate.

[0039] The present embodiment provides two structures of the degree calibration assembly, which coexist in the calibration device and can be selected when used. Referring to Figure 1 , the first degree calibration assembly includes a lens barrel 1. The lens barrel 1 includes a first barrel body 11 and a second barrel body 12, and the first barrel body 11 is slidably connected with the second barrel body 12. The lens 2 is arranged at one end of the first barrel body 11 away from the second barrel body 12, and the reflecting sheet 3 is arranged at one end of the second barrel body 12 away from the first barrel body 11.

[0040] It should be noted that the myopia of human eye is mainly divided into two types, one of which is axial myopia. Axial myopia is the most common myopia at present, which is manifested as that the anterior-posterior diameter (ocular axis) of the eye exceeds the normal length, that is, the retina is moved backward, but the curvature of the cornea and the lens is normal. This causes the light to be imaged on the original position of the retina after passing through the lens, resulting in blurred imaging.

[0041] In the embodiment, the first barrel 11 and the second barrel 12 are slidingly sleeved, which is equivalent to simulating the axial myopia of the human eye. When the first barrel 11 and the second barrel 12 are slidingly lengthened, the specific length of the reflector 3 and the lens 2 is lengthened, which is equivalent to the lengthening of the ocular axis, simulating the myopic eye. When the first barrel 11 and the second barrel 12 are shortened, it is equivalent to the shortening of the ocular axis, simulating the hyperopic eye.

[0042] As an example, the distance between the lens 2 and the reflector 3 can be controlled in the range of -5.0D—+4.0D. In order to improve the smoothness of the sliding of the first barrel 11 and the second barrel 12 and prevent the relative rotation between them, the application provides a sliding groove 112 on the second barrel 12 and a stopper 111 on the first barrel 11. The stopper 111 is fixedly connected with the first barrel 11 and protrudes into the sliding groove 112. When the first barrel 11 slides relative to the second barrel 12, the second barrel 12 slides along the stopper 111 within the range of the sliding groove 112.

[0043] Referring to Figure 5 , Figure 5 In some optional embodiments, the lens barrel 1 further comprises a distance calibration device 4, and the distance calibration device 4 comprises an indicating block 41 and a scale 42, and the indicating block 41 and the scale 42 are arranged on the first barrel 11 and the second barrel 12 respectively.

[0044] It should be understood that the indicating block 41 and the scale 42 are arranged on the first barrel 11 and the second barrel 12 respectively. The indicating block 41 can be arranged on the first barrel 11 or the second barrel 12. When the indicating block 41 is connected to the first barrel 11, the scale 42 is connected to the second barrel 12; when the indicating block 41 is connected to the second barrel 12, the scale 42 is connected to the first barrel 11. The distance between the lens 2 and the reflector 3 is calculated by the scale 42 and the indicating block 41, so as to obtain the simulated myopia degree.

[0045] Referring to Figure 1 In some possible embodiments, a sealing ring 5 is arranged between the first barrel 11 and the second barrel 12. The sealing ring 5 in the application has two main functions. One is to seal the first barrel 11 and the second barrel 12 to prevent water vapor from entering the inside; the other is to provide sliding damping, so that the sliding between the first barrel 11 and the second barrel 12 has a better quality.

[0046] Referring toFigure 2 、 Figure 3 、 Figure 5 、 Figure 5 The second power calibration assembly structure is provided in the application. The power calibration assembly comprises a connecting block 6 and a plug-in lens 7 which is clamped with the connecting block 6. The connecting block 6 is connected with the lens barrel 1 and is arranged on the side of the lens 2 away from the reflector 3.

[0047] It should be noted that the second power calibration assembly structure in the embodiment can be used alone or simultaneously with the first power calibration assembly.

[0048] The second power calibration assembly structure in the embodiment simulates the second myopia of human eyes, i.e. refractive myopia. Refractive myopia is relatively rare in daily life. It is mainly that the curvature of the cornea or the lens is too large (thick), or these structures are not coordinated, which causes the light to be refracted too strongly, resulting in imaging in front of the retina, while the eye axis length is normal.

[0049] It should be understood that the plug-in lens 7 is a plug-in lens, i.e. the middle part of the plug-in lens is embedded with a lens. The lens can be a convex lens or a concave lens. When the plug-in lens 7 is installed on the side of the lens 2 originally occupied by the reflector 3, it is equivalent to adjusting the thickness of the lens. When the convex lens is inserted, it is equivalent to thickening the lens, simulating a myopic eye; when the concave lens is inserted, it is equivalent to thinning the lens, simulating a hyperopic eye.

[0050] When the second power calibration assembly is used alone, the first barrel 11 and the second barrel 12 can be adjusted to the 0D position, and only the plug-in lens 7 is used for simulation.

[0051] When the range of the first power calibration assembly cannot meet the requirements, the range can be increased by the plug-in lens 7. For example, if a -7.0D myopic eye needs to be simulated, the lens barrel 1 can be pulled to a -5.0D position, and then a +2.0D convex lens is inserted.

[0052] Referring to Figure 5 , in order to realize the connection between the connecting block 6 and the plug-in lens 7, the connecting block 6 is provided with at least one clamping groove 61 in the application, and the shape of the clamping groove 61 is the same as the shape of the plug-in lens 7. In order to facilitate operation, the clamping groove 61 is an annular groove in the application. The clamping groove 61 can be clamped with the plug-in lens 7 by interference fit, and the interference fit is made of elastic materials such as rubber; or gap fit can be used.

[0053] Continuing to refer to Figure 3 , in order to facilitate operation, the number of clamping grooves 61 is three in the application. In the embodiment, the three clamping grooves 61 can be inserted into a concave lens, a convex lens and an astigmatism lens, respectively, to cope with various situations.

[0054] It should be noted that the insert lens 7 in the present application can calibrate the astigmatism detection of the vision screening instrument in addition to providing simulated myopia degree.

[0055] Astigmatism is a common refractive abnormality of the eye, which is mainly manifested as blurred vision, ghosting or object deformation. Normally, the eyeball is like a smooth sphere, and the curvature in different directions is basically consistent, which can accurately focus light on the retina. However, the surface of the eyeball (especially the cornea) of the astigmatism patient has curvature difference in different directions, such as different curvature in vertical and horizontal directions, which causes the light entering the eye to be unable to converge into a clear focus, but to be dispersed into two intersecting "light bands", and finally to form a blurred image.

[0056] In the art, "axis position" generally represents the direction of astigmatism, and whether the line in a certain direction seen by the astigmatism eye is clear or blurred is determined by the axis position of the astigmatism.

[0057] In the present application, an axis position scale 8 is further arranged between the connecting block 6 and the lens barrel 1, and the axis position scale 8 is coaxially arranged with the lens barrel 1 and used for calibrating the astigmatism direction. Specifically, the identification line 71 is correspondingly arranged on the insert lens 7, and the axis position scale 8 is used for calibrating the astigmatism direction of the insert lens 7. ​ When the insert lens 7 provides a simulated astigmatism eye with an axis position of 120°, the identification line 71 is aligned with 120° on the axis position scale 8, and at this time, the astigmatism detection function of the vision screening instrument can be calibrated.

[0058] In some optional embodiments, a pupil simulation assembly is further included, and the pupil simulation assembly includes an insert plate 9, which is eccentrically connected with the lens barrel 1 through a rotating shaft 92. The insert plate 9 is arranged on the side of the lens 2 away from the reflector 3, and the insert plate 9 is coaxially provided with a plurality of round holes 91 around the rotating shaft 92.

[0059] In the present embodiment, the round holes 91 on the insert plate 9 are used for simulating the pupil of the human eye. As an example, three round holes 91 are arranged, and the diameters of the three round holes 91 are 3mm, 7mm and 5mm respectively, wherein the 5mm diameter is used for simulating the diameter of the normal human eye pupil, and the 3mm and 7mm are used for simulating different conditions, such as mydriasis, too strong or too weak light. By turning the tail of the insert plate 9, the insert plate 9 is rotated around the rotating shaft 92, and the diameter of the required round hole 91 is selected. Among them, the tail of the insert plate 9 is the side of the insert plate 9 that is exposed to the outside and opposite to the round hole 91.

[0060] In some optional embodiments, a base 10 is further included, and a support rod 101 is rotatably connected above the base 10, and the support rod 101 is fixedly connected with the lens barrel 1. After the calibration device is fixed by the base 10, the angle can be adjusted by the support rod 101 to adapt to different equipment.

[0061] In the description of the utility model, it is necessary to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or positional relationship is based on the orientation or positional relationship shown in the drawing, is only for the convenience of describing the utility model and simplifying the description, and is not indicating or implying that the device or element indicated must have a particular orientation, is constructed and operated in a particular orientation, therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0062] In the description of the utility model, it is necessary to explain, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be broadly understood, for example, can be fixed connection, can also be detachable connection, or integrally connected;Can be mechanical connection, can also be electrical connection;Can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

Claims

1. A vision screening instrument calibration device, characterized by, The application relates to a lens barrel, which comprises a lens barrel body and a lens arranged coaxially inside the lens barrel body. The lens is arranged at one end of the lens barrel body, and a reflecting sheet is arranged at the other end of the lens barrel body away from the lens; the side of the reflecting sheet close to the lens is an arc-shaped concave surface. The application further relates to a degree calibration assembly for providing different calibration degrees.

2. The vision screening chart calibration device of claim 1, wherein, The degree calibration assembly comprises a lens barrel body. The lens barrel body comprises a first barrel body and a second barrel body, and the first barrel body is slidably sleeved with the second barrel body. The lens is arranged at one end of the first barrel body away from the second barrel body, and the reflecting sheet is arranged at one end of the second barrel body away from the first barrel body.

3. The vision screening chart calibration device of claim 2, wherein, The lens barrel body further comprises a distance calibration device, and the distance calibration device comprises an indicating block and a scale arranged on the first barrel body and the second barrel body respectively.

4. The vision screening chart calibration device of claim 2, wherein, A sealing ring is arranged between the first barrel body and the second barrel body.

5. The vision screening chart calibration device of any one of claims 1-4, wherein, The degree calibration assembly further comprises a connecting block and a plug-in lens plate clamped with the connecting block. The connecting block is connected with the lens barrel body and arranged at the side of the lens away from the reflecting sheet.

6. The vision screening chart calibration device of claim 5, wherein, The connecting block is provided with at least one clamping groove.

7. The vision screening chart calibration device of claim 6, wherein, The number of the clamping grooves is three.

8. The vision screening chart calibration device of claim 6, wherein, An axial position scale is further arranged between the connecting block and the lens barrel body, and the axial position scale is coaxially arranged with the lens barrel body and used for calibrating the astigmatism direction.

9. The vision screening chart calibration device of claim 8, wherein, The application further relates to a pupil simulation assembly, which comprises a plug-in plate and a rotating shaft eccentrically connected with the lens barrel body. The plug-in plate is arranged at the side of the lens away from the reflecting sheet, and the plug-in plate is coaxially provided with a plurality of round holes which are circumferentially distributed around the rotating shaft.

10. The vision screening chart calibration device of claim 9, wherein, A support rod is rotatably connected above a base, and the support rod is fixedly connected with the lens barrel body.

Images