Refractive measurement device and its portable optometer

Abstract

The present disclosure provides a refractive power measuring device, which includes: a detection light source that emits detection light; a light source lens group that projects the detection light into an eye to be measured; an imaging lens group that includes an annular light spot forming unit; a light spot image extraction mechanism that collects an annular light spot image formed by the imaging lens group; and a control module that receives the annular light spot image information obtained by the light spot image extraction mechanism and determines a refractive power detection result. Further, the present disclosure provides a portable optometer. The refractive power measuring device and the portable optometer of the present disclosure can perform optometry in an objective manner, have a compact structure, and are convenient for refractive screening.

Description

Technical Field

[0001] The present disclosure relates to ophthalmic optometry applications. More particularly, the present disclosure relates to a refractive power measuring device, and a portable optometer using such a refractive power measuring device, in particular, an objective-type portable optometer. Background Art

[0002] The current situation of myopia in China is severe. According to statistics, in 2020, the overall myopia rate of children and adolescents in China was 52.7%, among which the myopia rate of 6-year-old children was 14.3%, that of primary school students was 35.6%, that of junior high school students was 71.1%, and that of senior high school students was 80.5%. In addition to reducing the time of using eyes at close range, increasing the time of outdoor activities, and mastering correct eye-using habits and postures for myopia prevention and control, an important task is to detect refractive errors as early as possible and intervene. Therefore, it is particularly important to carry out regular refractive screening among school-age populations. Therefore, a handheld optometer with a compact structure and convenient use is the best choice for rapid screening of refractive errors in a large number of people.

[0003] There have been various solutions in the existing prior arts.

[0004] Patent Document 1

[0005] Application No. CN201310563823.0, Publication No. CN103654708B, Applicants Shenzhen Serton Technology Co., Ltd. | Shenzhen Motin Imaging Technology Co., Ltd. This patent provides a handheld vision detection device, including: an imaging lens group composed of at least one imaging lens and a vision chart, and the cornea of the person to be tested is located at the focal point on one side of the imaging lens group; the device further includes a sleeve arranged in the middle of one end thereof and an adjustment knob sleeved on the sleeve; indicating lines are marked on the outer circumference of the sleeve, and the vision chart is arranged inside the sleeve and moves away from or approaches the imaging lens group together with the sleeve when the adjustment knob is rotated; a scale value with a diopter of 0 is marked on the outer circumference of the adjustment knob; or the scale value with a diopter of 0 is marked on the outer circumference of the sleeve along its axis direction; the vision chart is just at the focal point on the other side of the imaging lens group when the diopter is 0.

[0006] The detection process provided by Patent CN103654708 A relies too much on the judgment and cooperation of the testee, which is not conducive to the examination of young children and takes a long time.

[0007] Patent Document 2

[0008] Application No. 202110676463.X, Publication No. CN113413130A, Invention Title "A Small Optometry and Visual Acuity Tester with a Short Main Optical Path". It discloses a small optometry and visual acuity tester with a short main optical path, which is a small optometry device for subjective and objective examinations. The instrument includes a main optical path and three branch optical paths. The main optical path is successively provided with a first beam splitter, a first convex lens, a second convex lens, a second beam splitter, a third beam splitter, and a wavefront sensor. The first beam splitter, the third convex lens, the pupil imaging camera, and the first convex lens are fixed on the housing in contact with the eye according to the optical path structure. The second convex lens, the second beam splitter, the fourth convex lens, the light source, the third beam splitter, the wavefront sensor, the fifth convex lens, and the visual target display device are fixed on the movable housing according to the optical path structure.

[0009] This technical solution provides a handheld optometry solution, which includes objective optometry and subjective optometry. It is relatively complex to use and is not conducive to widespread refractive screening.

[0010] Patent Document 3

[0011] Patent Authorization Publication No. CN101718542B, titled "An Optical Ranging Device and Its Portable Optometry Tester", with the applicant being Shenzhen Serton Technology Co., Ltd. This patent provides an optical ranging device based on the SHACK-HARTMANN wavefront measurement principle, including: a light source for emitting detection light, a light source lens group for injecting the detection light into the eyeball to be measured (109), a measurement arm lens group for magnifying the wavefront change of the detection light reflected back by the cornea of the eyeball to be measured (109), an array optical element for measuring the magnified wavefront change, and a processing unit including a photoelectric conversion module for analyzing and processing the light passing through the array optical element to obtain the distance between the eyeball to be measured (109) and the measurement arm lens group. Compared with the prior art, the advantage of the present invention is that when the portable optometry tester is measuring, it can accurately determine its distance from the eyeball to be measured and further improve the detection accuracy.

[0012] Regarding the Shack-Hartmann wavefront sensor, it is a main application of microlenses. The microlens array is usually placed at a specific position in front of the CCD array, so that the plane wavefront imaged on the CCD sensor will form a regular bright spot pattern. If the light imaged on the CCD sensor consists of regularly spaced light spots including deviated light spots and disappearing light spots, it means that the wavefront is distorted. These information can be used to calculate the shape of the wavefront incident on the microlens array. The Shack-Hartmann wavefront sensor can be used to characterize the performance of an optical system, and can also be used to control adaptive optical elements by real-time monitoring of the wavefront to eliminate wavefront distortion before imaging.

[0013] The content of the cited publications is incorporated herein by reference in its entirety. Summary of the Invention

[0014] [Technical Problem to be Solved]

[0015] The present disclosure aims to provide a refractive measurement device and a portable optometer that are more suitable for performing refractive screening on school-age populations. Compared with the prior art, the technical solution herein is, in view of the above application characteristics, to simplify the product structure on the premise of meeting the usage requirements, making the instrument small and compact and reducing costs. In addition, it is configured to adopt an objective measurement method to minimize the need for subjective responses from the subject during the measurement.

[0016] [Technical Solution]

[0017] To solve one of the above technical problems, in a first aspect of the present disclosure, there is provided a refractive measurement device, which includes: a detection light source that emits detection light; a light source lens group that projects the detection light into an eye to be measured; an imaging lens group that includes an annular light spot forming unit; a light spot image extraction mechanism that collects an annular light spot image formed by the imaging lens group; and a control module that receives the annular light spot image information obtained by the light spot image extraction mechanism and determines a refractive detection result.

[0018] There is a data processing unit in the control module, in which a preset algorithm program is stored. The extracted annular light spot image is fitted to a corresponding ring. Typically, the obtained ring is an ellipse. Thereby, the control module determines an ellipse equation based on the annular light spot image. Based on the parameters of the obtained ellipse equation, the spherical lens power of the measured eye and the astigmatic lens power of the measured eye can be obtained.

[0019] Further, optionally, the annular light spot forming unit includes an annular lens, that is, the incident light forms the above annular light spot image through the annular lens.

[0020] Preferably, in a further aspect of the present disclosure, there is provided an annularly arranged sub-lens array to replace the annular lens, which forms a discontinuous annular light spot image. The control module fits the discontinuous annular light spot image into a continuous annular image, and obtains the parameters of the ellipse equation in the same way.

[0021] In addition to using a group of annular sub-lenses, multiple groups of concentric annular sub-lens arrays can also be arranged, that is, the number of rings N≥1. Preferably, N is 1, N is 2, N is 3, N is 4 or N is 5. The more concentric rings there are, the greater the accuracy of fitting the ellipse to calculate the refractive power. Obtaining an elliptical light spot by using an annularly arranged sub-lens array is actually fitting an elliptical light spot, which can effectively reduce the cost of obtaining an annular lens. In addition, in actual production, it is easier to control the manufacturing accuracy of the product, and to improve the measurement accuracy of the refractive measurement device.

[0022] The refractive power measuring device provided according to the first aspect preferably further includes a fixation target unit, which can be selected from a liquid crystal display, a plasma display, a field emission display, an organic light emitting display, an illuminated chart, and an illuminated microstructure. More preferably, it includes a pupil imaging device. The pupil imaging device is used for acquiring an image of the eye to be tested, wherein the pupil imaging device includes a pupil illumination mechanism and a pupil imaging camera. The pupil imaging camera may optionally include a focusing lens.

[0023] Another aspect of the present disclosure provides a portable optometer using the refractive power measuring device of the above aspect.

[0024] Preferably, in the portable optometer of the present disclosure, the pupil imaging device includes a pupil illumination mechanism and a pupil imaging camera with a focusing lens. By controlling the focusing lens, a long-distance working mode and a short-distance working mode can be set.

[0025] The long-distance working mode provides a working mode for binocular imaging. When the distance from the human eye is a certain distance, generally more than 1 meter, the subject's both eyes simultaneously fixate on the target on the instrument, and images of both eyes are captured. The eye images obtained in the long-distance working mode are characterized by the control module into image structures of the upper eyelid, lower eyelid, iris, and pupil. In the long-distance working mode, the positions of the irises of the left and right eyes in the eye sockets can be extracted, and strabismus can be screened based on the positional relationship between the irises and the eye sockets in both eyes.

[0026] The short-distance working mode is an operation mode applied during the optometry process. The optometer is generally 30 mm away from the human eye, and the pupil is imaged to assist the operator in aligning the instrument with the pupil of the human eye to complete the optometry. Since the instrument is 30 mm away from the pupil at this time, the camera for capturing the pupil image needs to be focused, and the working distance is adjusted from 1 meter for binocular imaging to 30 mm.

[0027] [Advantages of the Invention]

[0028] The refractive power measuring device of the present disclosure can achieve completely objective refractive detection, and basically no response from the subject is required.

[0029] In the prior art, for objective refractive detection, a Hartmann wavefront sensor has been used. It is a method of dividing the wavefront with a microlens array and then obtaining the wavefront error by analyzing the offset between the spot in the sub-aperture and the ideal spot.

[0030] In a preferred embodiment of the present disclosure, based on the annularly arranged sub-lens array, when the beacon light reflected from the fundus passes through the sub-lens array, the center points of the focused light spots of the sub-lenses are elliptically distributed (circular when there is no refractive power) due to the influence of eye refractive error. The center points of this annularly arranged array are fitted into an ellipse with the center of the annularly arranged sub-lens array as the center of symmetry, and its general equation is a + bXY + cX 2 + dY 2 = 0. According to the obtained coordinate values of the light spot center points, substituting them into the equation can solve for the values of a, b, c, and d, and then the refractive data of the measured eye, including spherical power, astigmatic power, and astigmatic axis, can be obtained.

[0031] The technical solution of the present disclosure adopts a more concise component arrangement. Based on the annularly arranged sub-lenses receiving the beacon light reflected from the fundus to complete optometry, it has a lower cost than the conventional Hartmann wavefront sensor. Therefore, the cost of the detection device is effectively reduced, and more flexible, more optional, and practical implementation means are provided.

[0032] The portable optometer provided by the present disclosure adopts the above-mentioned refractive measurement device to realize objective vision detection and refractive correction screening. In addition, in a preferred embodiment, the pupil imaging device is set to be in a long-distance working mode and a short-distance working mode through simple focusing operations. The long-distance working mode can be used for strabismus screening, making the device function more perfect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings illustrate exemplary embodiments of the present disclosure and are used together with the description to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure, and the drawings are included in this specification and form a part of this specification.

[0034] Figure 1 Schematically showing the optical path arrangement of an embodiment of the refractive measurement device of the present disclosure;

[0035] Figure 2 Schematically showing an embodiment of the annular light spot forming unit, the annular light spot forming unit is composed of a sub-lens array;

[0036] Figure 3 Schematically showing Figure 2 An annularly arranged light spot image formed by the shown annular light spot forming unit;

[0037] Figure 4 Schematically showing another embodiment of the annular light spot forming unit, the annular light spot forming unit is composed of a sub-lens array;

[0038] Figure 5 It is a schematic diagram of another embodiment of the annular light spot forming unit and its imaging, wherein the annular light spot forming unit is composed of an annular lens;

[0039] Figure 6 This is a layout block diagram of an embodiment of the disclosed portable optometer, showing the close-range operation mode;

[0040] Figure 7 is Figure 6 The usage state of the disclosed portable optometer shown in the long-range operation mode;

[0041] Figure 8 is an information flow block diagram;

[0042] Figure 9 shows the pupil image transmitted to the control module and displayed on the operation display screen, used to guide the operator to align the pupil of the eye to be measured with the optical axis of the instrument, and

[0043] Figure 10 shows the binocular images extracted in the remote mode.

[0044] Description of reference numerals:

[0045] 1 Eye

[0046] 2 First beam splitter

[0047] 3 Second beam splitter

[0048] 4 Pupil imaging camera

[0049] 5 Beacon light source collimator

[0050] 6 Beacon light source

[0051] 7 First focusing lens

[0052] 8 Second focusing lens

[0053] 9 Third beam splitter

[0054] 10 Visual target imaging objective lens

[0055] 11 Fixation target

[0056] 12 Annular light spot forming unit

[0057] 13 Light spot image extraction mechanism

[0058] 15 Sub-lens

[0059] 110 Instrument housing

[0060] 130 Operation prompt screen

[0061] 140 Control module

[0062] 150 Optical module

[0063] 160 Eye positioning hole to be measured

[0064] 501 Annular lens

[0065] 502 Optical axis

[0066] 503 Spot image

[0067] 504 Central part of the annular lens

[0068] 1000 Portable optometer Detailed implementation manners

[0069] The present disclosure will be further described in detail below in conjunction with the accompanying drawings and implementation manners. It can be understood that the specific implementation manners described herein are only used to explain the relevant content and do not limit the present disclosure. Additionally, it should be noted that for the sake of convenience of description, only the parts related to the present disclosure are shown in the accompanying drawings.

[0070] Unless otherwise specified, the exemplary embodiments / examples shown will be understood to provide exemplary features of various details of some ways that can implement the technical concept of the present disclosure in practice. Therefore, unless otherwise specified, the features of various embodiments / examples can be additionally combined, separated, interchanged, and / or rearranged without departing from the technical concept of the present disclosure.

[0071] In the accompanying drawings, cross - hatching and / or shading are generally used to make the boundaries between adjacent components clear. Thus, unless stated, the presence or absence of cross - hatching or shading does not convey or imply any preference or requirement for the specific material, material properties, dimensions, proportions, commonality between the components shown, and / or any other characteristics, attributes, properties, etc. of the components. In addition, in the accompanying drawings, for the purpose of clarity and / or description, the dimensions and relative dimensions of the components may be exaggerated. When the exemplary embodiments can be implemented differently, the specific process sequences can be executed in an order different from that described. For example, two consecutively described processes can be executed substantially simultaneously or in an order opposite to that described. In addition, the same reference numerals denote the same components.

[0072] When a component is referred to as being "on" or "above" another component, "connected to" or "coupled to" another component, the component can be directly on the other component, directly connected to or directly coupled to the other component, or there can be an intermediate component. However, when the component is referred to as being "directly on" another component, "directly connected to" or "directly coupled to" another component, there is no intermediate component. For this reason, the term "connection" can refer to physical connection, electrical connection, etc., and can have or not have an intermediate component.

[0073] For descriptive purposes, the present disclosure may use spatial relative terms such as "under", "below", "beneath", "lower", "above", "upper", "on", "over", "higher", and "side (e.g., as in "sidewall")" to describe the relationship of one component to another (other) component as shown in the figures. In addition to the orientation depicted in the figures, the spatial relative terms are also intended to encompass different orientations of the device during use, operation, and / or manufacturing. For example, if the device in the figures is flipped, a component described as "under" or "beneath" another component or feature will then be positioned "above" the other component or feature. Thus, the exemplary term "under" can encompass both an "above" and a "below" orientation. Additionally, the device may be otherwise positioned (e.g., rotated 90 degrees or at other orientations), and accordingly, the spatial relative descriptors used herein are to be interpreted accordingly.

[0074] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" are also intended to include the plural forms. Additionally, when the terms "comprises" and / or "comprising" and variations thereof are used in this specification, it is specified that there are the stated features, integers, steps, operations, components, assemblies, and / or groups thereof, but does not preclude the presence or addition of one or more other features, integers, steps, operations, components, assemblies, and / or groups thereof. It should also be noted that, as used herein, the terms "substantially", "about", and other similar terms are used as approximate terms and not as terms of degree, and thus are used to interpret the inherent deviations of measured, calculated, and / or provided values that would be recognized by a person of ordinary skill in the art.

[0075] In the description of this specification, descriptions with reference to the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment / way or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments / ways or examples in a suitable manner. Additionally, without contradiction, those skilled in the art may combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0076] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0077] Embodiment 1

[0078] As Figure 1 shown, it schematically shows the optical path arrangement and measurement operation of the refractive power measuring device of the present disclosure.

[0079] First, the pupil alignment step is completed for the eye 1 to be measured.

[0080] Then, the detection light source is turned on. The detection light source in the embodiment is the beacon light source 6. The light emitted by the beacon light source 6 is collimated into parallel light by the beacon light collimating lens 5, and then enters the eye 1 to be measured through the second beam splitter 3 and the first beam splitter 2. Subsequently, the backward reflected light from the fundus of the eye 1 passes through the first beam splitter 2, the first focusing lens 7, the second focusing lens 8, the third beam splitter 9, and enters the spot image extraction mechanism 13 (imaging device) after passing through the annular spot forming unit 12. The spot image extraction mechanism 13 captures an annular or circumferentially arranged spot image.

[0081] In this embodiment, the annular spot forming unit 12 is a single-ring sub-lens array as Figure 2 shown, which schematically shows an array of sub-lenses 15 arranged in a ring used in the annular spot forming unit 12 in this embodiment. The centers of the sub-lenses 15 can be fitted into a circle. For the application of vision screening, considering the compromise between economy and functional performance, a single-ring sub-lens array is preferably used, that is, the number of rings N = 1. Only setting one annular sub-lens array can meet the requirements of fitting an ellipse to calculate the refractive power in vision screening tests, and it is relatively easy to process and the processing cost is low.

[0082] Further explanation, the light emitted from the third beam splitter 9 forms spots after passing through the sub-lenses 15. Typically, the centers of the spots formed by the sub-lenses 15 are connected together to fit an ellipse. In a special case, that is, when the measured eye has no astigmatism, the array formed by the spots can be fitted into a circle, as Figure 3 illustrated. In other words, when the human eye has a refractive power, including myopia or hyperopia accompanied by astigmatism, the typical fitting image is an ellipse at this time. Especially when there is no astigmatism, the fitting image is a circle, that is, the fitting image is a circle in the case of simple myopia / hyperopia, and the fitting image is an ellipse in the case of astigmatism.

[0083] The spot image extraction mechanism 13 can be an imaging device, such as a CCD camera. The above-mentioned spot image is extracted and transmitted to the control module 140 ( Figure 1 not shown in the figure) for data processing.

[0084] The center points of the annularly arranged spot image array are fitted into an ellipse with the center of symmetry being the center of the annularly arranged sub-lens array. Its general equation is e + fXY + gX 2 + hY 2 = 0. According to the obtained coordinate values of the spot center points, substituting them into the equation can solve for the values of e, f, g, and h to determine the ellipse equation.

[0085] Let the angle between the minor axis of the ellipse and the x-axis in the Cartesian coordinate system be α. Substitute the rotation axis equation

[0086] X = xcosα - ysinα

[0087] Y = xsinα + ycosα

[0088] After substituting into the above-determined ellipse equation to eliminate X and Y, the ellipse equation is simplified to:

[0089] x 2 / a 2 + y 2 / b 2 = 1

[0090] where a is the spherical lens power of the measured eye, b - a is the astigmatic power of the measured eye, and α is the astigmatic axis. In particular, when a = b, the ellipse is a circle and the measured eye has no astigmatic power.

[0091] In this embodiment, a fixation target 11 is also provided. During the refractive measurement of the measured eye, a fixed pattern, such as a crosshair, is displayed on the fixation target 11. This pattern is imaged on the retina of the tested eye 1 by the target imaging objective lens 10. During the measurement, the tested person ensures the stable position of the eye during the measurement by staring at this pattern.

[0092] The fixation target module can be selected from a liquid crystal display, a plasma display, a field emission display, an organic light-emitting display, an illuminated chart, and an illuminated microstructure.

[0093] Embodiment 2

[0094] The difference between this embodiment and Embodiment 1 is that a multi-ring sub-lens array is adopted.

[0095] In the present disclosure, a sub-lens sub-array is used to obtain the effect of an annular lens. The number of sub-lens arrays N ≥ 1. When N = 1, for example Figure 2As shown, there is only one sub-lens array arranged in a ring; when N = 2, there are two concentric ring-shaped arranged sub-lens arrays. Further variant embodiments, for example, when N = 3, there are three concentric arranged sub-lens arrays. Further variant embodiments, for example, when N = 4, there are four concentric arranged sub-lens arrays. Further variant embodiments, for example, when N = 5, there are five concentric arranged sub-lens arrays. The more concentric rings there are, the greater the accuracy of fitting the ellipse to calculate the diopter.

[0096] Using a sub-lens array arranged in a ring to obtain an elliptical light spot is actually fitting an elliptical light spot, which can effectively reduce the cost of obtaining a ring lens. In addition, in actual production, it is easier to control the manufacturing accuracy of the product, and to improve the measurement accuracy of the diopter measurement device.

[0097] The advantage of increasing the number of rings is that the average value can be calculated after calculating the diopter with different rings as the final measurement result, improving the measurement accuracy.

[0098] Embodiment 3

[0099] The difference between this embodiment and Embodiments 1 and 2 is that the main component of the annular light spot forming unit 12 is an annular lens.

[0100] Figure 5 Schematically shows an arrangement of an annular lens. The configuration of the annular lens 501 is formed by rotating a lens section 360° around the optical axis 502. The central part 504 of the annular lens adopts a light-shielding or hollow design.

[0101] The diopter measurement process is as follows:

[0102] First, operate to align the pupil. After the pupil alignment step is completed, turn on the beacon light source 6. The beacon light source 6 is collimated into parallel light by the beacon light collimating lens 5, and then enters the eye to be measured 1 through the second beam splitter 3 and the first beam splitter 2. Subsequently, the backscattered light from the fundus of the eye 1 passes through the first beam splitter 2, the first focusing lens 7, the second focusing lens 8, the third beam splitter 9, and after imaging through the annular lens 501, enters the light spot image extraction mechanism 13. The light spot image extraction mechanism 13 collects the annularly arranged light spot image 503. Then, process the annular light spot image 503, extract its center line and fit it into an ellipse, and its general equation is e + fXY + gX 2 + hY 2 = 0. Take the coordinate values at different positions and substitute them into the equation to solve for the values of e, f, g, and h to determine the ellipse equation. The remaining processing is similar to that in Embodiments 1 and 2 above.

[0103] Embodiment 4

[0104] This embodiment provides a portable optometer 1000.

[0105] As Figure 6 、 Figure 7 and Figure 8 shown, the portable optometry instrument 1000 includes the following configurations: an instrument housing 110, an operation prompt screen 130, a control module 140, and an optical module 150.

[0106] In this embodiment, the operation prompt screen 130 is installed on the instrument housing 110 and is set to face the operator during use, so as to facilitate the operator to obtain measurement information and operation prompts, etc.

[0107] The optical module 150 adopts the Figure 1 shown optical path system, that is to say, the refractive device preferably adopts the refractive devices of the above-mentioned Embodiments 1-3.

[0108] The portable optometry instrument 1000 of this embodiment provides functions of binocular imaging and monocular imaging. Figure 6 It is shown that one eye is close to the positioning hole 160 of the eye to be measured, and monocular imaging is performed with it. During the measurement process, the operator can move the portable optometry instrument 1000 to align the optical center of the instrument (such as the Figure 1 shown principal optical axis) with the pupil center of the eye 1 (such as the Figure 9 shown).

[0109] In addition, as Figure 7 shown, the distance between the portable optometry instrument 1000 and the person to be measured is increased, so that the distance between the measured human eye and the portable optometry instrument 1000 is kept more than 1 meter, meeting the effect of binocular approximate distance vision. This process is used as a long-distance working mode for binocular imaging.

[0110] As Figure 1 shown, the pupil imaging camera 4 includes a focusing lens, which can be focused respectively for the near-distance and long-distance operation modes to meet the requirements of the corresponding working modes. The focusing operation button of the pupil camera 4 can be set on the outer surface of the housing 110 for the convenience of the operator to manually focus. It can also be set to input operation instructions to the control module 140 through prompts and responses on the operation prompt screen 130, and the control module 140 instructs and controls the action mechanism to perform actions, such as a servo motor operating the relevant focusing mechanism.

[0111] The following exemplarily describes the vision screening operation of the portable optometry instrument 1000:

[0112] 1. Binocular imaging

[0113] After the optometry instrument is started, optionally, it first enters the binocular imaging link. This process requires the distance between the human eye and the imaging instrument to be more than 1 meter, meeting the effect of binocular approximate distance vision. This process is used as a long-distance working mode.

[0114] When the optometer is more than 1 meter away from the eyes, the subject's both eyes simultaneously fixate on the eye positioning hole 160 on the optometer, and the binocular images at this time are captured by the pupil imaging camera 4 set in the optical module 150.

[0115] The extracted binocular image information is transmitted to the control module 140. The image recognition algorithm stored in the processing module built into the control module 140 recognizes the orbital, iris, and pupil structures, which are displayed on the operation prompt screen 130 and saved, for judging the positions of the binocular iris structures and pupils in the binocular orbits respectively. The binocular images are as Figure 10 illustrated.

[0116] The above binocular long-distance pupil imaging can be used for strabismus screening. In this embodiment, a scheme of adding a focusing lens to the pupil imaging part to capture binocular images at a long distance is adopted, which can achieve strabismus screening without adding complex structures.

[0117] 2. Pupil alignment

[0118] As described above and Figure 6 shown, the single eye to be measured is close to the eye positioning hole 160 for single-eye imaging. When performing pupil alignment, the front end of the portable optometer 1000 is pressed against the subject's forehead, and the pupil of the subject is illuminated by an infrared light source (not shown in the figure). The pupil imaging camera 4 is focused to make it focus in the close-distance working mode for clear imaging of the pupil, for pupil positioning before optometry. For convenient operation, buttons can be set on the optometer housing to achieve the switching operation of the two focusing modes of the pupil imaging camera with one key.

[0119] As Figure 9 shown, the pupil image information is transmitted to the control module 140. The control module 140 extracts the pupil image and marks the pupil center point. The control module 140 displays the relevant information on the operation prompt screen 130. The operator moves the position where the front end of the optometer is pressed against the forehead according to the pupil image and the marked pupil center point displayed on the operation prompt screen 130. By moving the optometer up, down, left, and right, the optometer optical axis auxiliary line displayed on the operation prompt screen 130 is made to coincide with the pupil center point, thus completing the pupil alignment.

[0120] 3. Measurement of refractive error of the eye

[0121] For the measurement of refractive error of the eye, refer to the descriptions of the above Embodiments 1-3.

[0122] Further explanation: To achieve a compact layout of the portable optometer 1000 and provide a purely objective optometer for rapid screening of refractive errors, in this embodiment, subjective optometry is not performed by correcting refractive errors. Therefore, the focusing lens group in the optical module 150 is fixedly arranged, that is, fixedly preset according to a normally refracting eye. The distance between the first focusing lens 7 and the second focusing lens 8 in the embodiment is fixedly arranged, and there is no manual knob on the optometer for the focusing lens group, that is, refractive correction is not performed, and after not setting refractive correction, there are no functional components required for the measured eye to judge the visual target display.

[0123] The present disclosure at least includes the following concepts:

[0124] Concept 1. A refractive measurement device, characterized by comprising:

[0125] A detection light source that emits detection light;

[0126] A light source lens group that injects the detection light into the eye to be measured;

[0127] An imaging lens group that includes an annular light spot forming unit;

[0128] A light spot image extraction mechanism that collects the annular light spot image formed by the imaging lens group;

[0129] A control module that receives the annular light spot image information obtained by the light spot image extraction mechanism and determines the refractive detection result.

[0130] Concept 2. The refractive measurement device according to Concept 1, characterized in that the annular light spot forming unit includes an annular lens.

[0131] Concept 3. The refractive measurement device according to Concept 1, characterized in that the annular light spot forming unit includes an annularly arranged sub-lens array.

[0132] Concept 4. The refractive measurement device according to Concept 3, characterized in that the annularly arranged sub-lens array is composed of polygonal or circular sub-lenses that are evenly distributed about the center, and the number N of annular rows arranged in the radial direction of the annularly arranged sub-lens array is 1, 2, 3, 4, or 5.

[0133] Concept 5. The refractive measurement device according to Concept 1, characterized by further comprising a fixation target unit.

[0134] Concept 6. A portable optometer using the refractive measurement device according to any one of Concepts 1-5.

[0135] Concept 7. The portable optometer according to Concept 6, characterized by further comprising a pupil imaging device.

[0136] Concept 8. The portable optometry device as described in Concept 7, wherein the pupil imaging device includes a pupil illumination mechanism and a pupil imaging camera with a focusing lens, and the long-distance working mode and the short-distance working mode can be set by controlling the focusing lens.

[0137] Concept 9. The portable optometry device as described in Concept 8, wherein in the short-distance working mode, the pupil imaging camera acquires the pupil image of the eye to be measured.

[0138] Concept 10. The portable optometry device as described in Concept 8, wherein in the long-distance working mode, the pupil imaging camera acquires the binocular images of the subject, and the identified images are characterized into the image structures of the upper eyelid, lower eyelid, iris and pupil by the control module.

[0139] Those skilled in the art should understand that the above embodiments are only for clearly illustrating the present disclosure, rather than limiting the scope of the present disclosure. For those skilled in the art, other changes or variations can be made based on the above disclosure, and these changes or variations are still within the scope of the present disclosure.

Claims

1. A portable optometer, characterized in that, A refractive measurement device is adopted, and the refractive measurement device includes: A detection light source that emits detection light; A light source lens group that injects the detection light into the eye to be measured; An imaging lens group that includes an annular light spot forming unit; A light spot image extraction mechanism that collects an annular light spot image formed by the imaging lens group; A control module that receives the annular light spot image information obtained by the light spot image extraction mechanism and determines the refractive detection result, wherein the annular light spot forming unit includes an annularly arranged sub-lens array, the annularly arranged sub-lens array is composed of polygonal or circular sub-lenses that are evenly distributed about the center, and the number N of annular rings arranged in the radial direction of the annularly arranged sub-lens array is 2, 3, 4, or 5.

2. The portable optometry device according to claim 1, wherein, It further includes a fixation target unit.

3. The portable optometry instrument according to claim 1, wherein, It further includes a pupil imaging device.

4. The portable optometry device according to claim 3, wherein, The pupil imaging device includes a pupil illumination mechanism and a pupil imaging camera with a focusing lens, and a long-distance working mode and a short-distance working mode are set by controlling the focusing lens.

5. The portable optometer according to claim 4, characterized in that, In the short-distance working mode, the pupil imaging camera acquires a pupil image of the eye to be measured.

6. The portable optometry instrument according to claim 5, characterized in that, In the long-distance working mode, the pupil imaging camera acquires binocular images of the subject, and the recognized images are characterized into image structures of the upper eyelid, lower eyelid, iris, and pupil via the control module.

Images