An intelligent self-service diopter measurement system

Abstract

The present invention provides an intelligent self-service diopter measurement system, comprising: a sight mark display device, used to display a sight mark to a testee; a camera, used to capture a frontal image of the testee; biased glasses, used to provide a biased diopter for the testee, and the biased diopter is determined according to the testee's historical diopter; a feedback device, through which the testee feeds back a sight mark recognition result to a central controller; and a central controller, used to obtain a distance between the testee and the sight mark according to the frontal image of the testee output by the camera, and obtain a diopter test result by combining the distance, the sight mark recognition result and the biased diopter. The diopter of the testee is undercorrected to a certain extent by the biased glasses, so that the diopter measurement range to be performed later is smaller, and a higher measurement accuracy can be achieved, and the test speed can be accelerated. At the same time, the moving distance range required for the testee's diopter measurement can be shortened, and a self-service diopter test is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of diopter measurement, and in particular to an intelligent self-service diopter measurement system. Background Art

[0002] The function of the eye to refract light is called refraction. The eye is a visual organ that uses light as an adaptive stimulus. From an optical point of view, the eyeball can be regarded as an optical system. Light emitted or reflected by external objects will be refracted through the eyeball, forming a clear and reduced inverted image on the retina. However, if the eyes are relaxed, the parallel light entering the eyeball will converge in front of or behind the retina, thus forming refractive error. Refractive error includes myopia, hyperopia and astigmatism.

[0003] Most of the current vision tests use standard logarithmic vision charts that meet the requirements of the national standard "GB11533-2011". On-site testing needs to be performed under the guidance of medical personnel at a fixed position or fixed space, which is not convenient. Existing refractive power measurement generally uses a Shack-Hartmann wavefront sensor to acquire a spot array image of the eye, and obtains refractive power information based on the spot array image. For example, the technical solution disclosed in the existing patent CN109645956B requires the guidance and participation of staff, and cannot achieve convenient self-service refractive power measurement.

[0004] Although the Chinese patent with publication number CN113197542A in the prior art discloses an online self-help vision detection system, the system is provided with a distance calculation module, a size calculation module, a display adjustment module and a vision judgment module, etc., and can perform online self-help vision detection, and can achieve accurate self-help vision detection without time and place restrictions and the help of assistants, but the patent is used to measure vision. When measuring vision (visual acuity), a visual distance must first be determined. The commonly used distances in medicine are 5 meters, 6 meters, 20 feet, etc., and then the sizes of the various levels of E-shaped sight marks on the display screen (such as 1.0, 0.8, 0.5) are determined. The measurement process is to find how large the sight mark can be seen by the subject at a given distance. When giving the visual acuity (visual acuity) result, the complete result generally indicates the visual distance during measurement, for example, the denominator 6 in the British visual acuity representation X / 6 means that the measured visual distance is 6 meters, and the denominator 20 in the American visual acuity representation X / 20 means that the visual distance is 20 feet. It can be seen that the distance calculation module of this patent obtains the distance in order to convert it into the standard viewing distance in order to obtain the vision test result from the national standard "GB11533-2011", which requires a fixed distance measurement and cannot be used for refractive power measurement. Summary of the invention

[0005] The present invention aims to at least solve the technical problems existing in the prior art and provide an intelligent self-service diopter measurement system.

[0006] In order to achieve the above-mentioned purpose of the present invention, the present invention provides an intelligent self-service refractive power measurement system, comprising: a sight mark display device, used to display the sight mark to the test subject; a camera, used to capture the front image of the test subject; biased glasses, used to provide biased refractive power for the test subject, wherein the biased refractive power is determined according to the historical refractive power of the test subject; a feedback device, through which the test subject feeds back the sight mark recognition result to the central controller; and the central controller, used to obtain the distance between the test subject and the sight mark according to the front image of the test subject output by the camera, and obtain the refractive power test result by combining the distance, the sight mark recognition result and the biased refractive power.

[0007] The above technical solution discloses a novel intelligent self-service refractive power measurement system. During measurement, the distance between the person being tested and the sight mark is not fixed. The person being tested can approach the sight mark from far to near, and the sight mark recognition result is continuously fed back to the central controller through the feedback device during the movement. After the person being tested moves to a position where the sight mark can be clearly seen, the central controller obtains the refractive power test result based on the distance between the person being tested and the sight mark, the sight mark recognition result and the biased refractive power, thereby realizing convenient self-service refractive power measurement. This system corrects the test subject's refraction to a certain extent (not completely corrected) by having the test subject wear biased glasses in advance, so that the subsequent refraction measurement range is smaller, which can achieve higher measurement accuracy and speed up the test. It can also shorten the moving distance range of the test subject when measuring the refraction, and also reduce the requirements for equipment such as cameras and displays; through the feedback device, the test subject can self-feed back the sight mark recognition results, realizing self-service refraction testing and reducing manpower investment; based on the front image of the test subject taken by the camera, not only can the distance between the test subject and the sight mark display device be obtained in real time, but also the test subject's expression, movement and the biased refraction of the biased glasses can be obtained based on the front image of the test subject, which can greatly expand the system function. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a system block diagram of an intelligent self-service diopter measurement system in a preferred embodiment of the present invention;

[0009] Figure 2 This is a schematic diagram of an E-shaped sight mark in a preferred embodiment of the present invention;

[0010] Figure 3 This is a schematic diagram of an astigmatism sight mark in a preferred embodiment of the present invention;

[0011] Figure 4 This is a schematic diagram of adjusting the size of an E-shaped sight mark in a preferred embodiment of the present invention;

[0012] Figure 5This is a schematic diagram of adjusting the size of the astigmatism sight mark in a preferred embodiment of the present invention;

[0013] Figure 6 It is a schematic diagram of obtaining the distance between the tested person and the sight mark in a preferred embodiment of the present invention;

[0014] Figure 7 It is a schematic diagram of a real-time position display area in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0015] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0016] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0018] The present invention discloses an intelligent self-service diopter measurement system. Figure 1 As shown, it includes: a sight mark display device, which is used to display the sight mark to the test subject; a camera, which is used to capture the front image of the test subject; biased glasses, which provide biased diopter for the test subject, and the biased diopter is determined according to the historical diopter of the test subject; a feedback device, through which the test subject feeds back the sight mark recognition result to the central controller; the central controller is used to obtain the distance between the test subject and the sight mark according to the front image of the test subject output by the camera, and obtain the diopter test result by combining the distance, the sight mark recognition result and the biased diopter.

[0019] In this embodiment, the system can be used to measure a variety of refractive powers, such as myopia, hyperopia, astigmatism, myopia + astigmatism, etc. When measuring the equivalent spherical diameter refractive error (i.e., refractive power) of myopia or hyperopia, the Tumbling E sight mark on the international visual acuity chart (e.g. Figure 2 ) or C sight mark, such as Figure 2 As shown, the direction of the letter sight mark can be in four directions: up, down, left, and right, or in an inclined direction.

[0020] In this embodiment, when the system tests the refractive error of astigmatism, the following method can be used: Figure 3 The astigmatism sight mark shown is composed of a series of stripes in different directions. In each group of stripes, one line may be dotted (which one is dotted is randomly generated by the system). When measuring astigmatism, the test subject needs to report which line is dotted or there is no dotted line through the feedback device.

[0021] In this embodiment, the sight mark display device is located in front of the test subject. Preferably, the sight mark display device is a display connected to the central controller; the display is used to display the sight mark, or the display is used to display the sight mark and the operation instruction, and the operation instruction is preferably but not limited to "step forward" or "step back" or "stand still" or "please give feedback" etc. The display is preferably but not limited to a computer display screen or a TV screen or an LED display screen or a liquid crystal display screen with a communication interface, and the display is connected to the central controller through the communication interface. The central controller is preferably but not limited to a computer host or a laptop computer or an embedded system with multiple interfaces.

[0022] In this embodiment, the camera is located in front of the person being tested. To simplify calculation results, it is further preferred that the camera and the display are at the same distance from the person being tested. Specifically, the camera can be fixed to the upper end of the display by a mounting clip or an adhesive mount.

[0023] In this embodiment, the lens on the biased glasses can be a simple myopia, hyperopia or astigmatism biased lens, or a combination of myopia and astigmatism lenses, etc. Preferably, in order to facilitate the installation of the lens, a lens mounting groove is provided on the biased glasses. In the myopia biased lens group, there are multiple myopia lenses with spherical diameter degrees, such as -100, -200, -250, -300, -400, -500, etc. If the test subject is myopia + astigmatism, then the horizontal cylinder diameter degree -75, -150, etc. are added to the above spherical diameter degrees; or, the vertical cylinder diameter degree -75, -150, etc. are added to the above spherical diameter degrees. The hyperopia biased lens group includes degrees of +100, +200, +300, +400, etc. The biased diopter of the biased glasses is the spherical diameter degree or the horizontal cylinder diameter degree of the lens or the sum of the horizontal cylinder diameter degree and the spherical diameter degree. Preferably, if the historical refractive powers of the left and right eyes of the test subject are different, the offset refractive powers of the left and right lenses can be set to be different accordingly.

[0024] In this embodiment, the existing Chinese patent with publication number CN113197542A is used to measure vision. In the test of this patent, undercorrected biased glasses cannot be used, otherwise the vision measurement result will be incorrect. However, when measuring the diopter of the present invention, the distance is uncertain and there is no fixed standard. The measurement process is to find at what distance the subject can see the sight mark given only one sight mark size. It can be seen that the measurement purpose, measurement index, measurement method and process, and calculation of the results of the patent CN113197542A and the present invention are different.

[0025] In this embodiment, it is preferred to know the historical refractive power of the test subject in advance so that the biased refractive power of the offset glasses after the lenses are installed is close to the historical refractive power. Specifically, according to the historical record of the refractive power of the myopic patient, a relatively close undercorrected degree is selected, and the test subject wears the glasses for refraction measurement. The undercorrected amount can be as small as about -100 degrees, or as large as -200 degrees, -250 degrees, -300 degrees, etc. The larger the undercorrected amount, the fewer the number of offset glasses required. For example: according to the record of about -400 degrees of myopia, patients with undercorrected glasses of -200 degrees or -250 degrees can be allocated. For test subjects with severe astigmatism, astigmatic offset lenses can be used, and the method is the same as the principle of undercorrection of the spherical degree of myopia offset mentioned above. For example: a test subject with -150 degrees of astigmatism is allocated with -75 degrees of offset. For hyperopic test subjects, the offset glasses used should be overcorrected hyperopia degrees. For example, for patients with +200 degrees of hyperopia, +300 degrees or +400 degrees of offset glasses are prescribed. Rough offset can reduce the number of offset glasses. For patients with combined hyperopia and astigmatism, the spherical diameter needs to be overcorrected, while the cylindrical diameter does not need to be overcorrected.

[0026] In this embodiment, if there is no biased glasses, in order to measure a wide range of diopters, the distance between the person being tested and the display is generally as far as 2 meters or more, and as close as 10 centimeters, which requires that both the camera and the display have very high resolutions, the former requirement is determined by the long distance, and the latter requirement is determined by the short distance. The biased glasses allow the moving distance of the person being tested to be within a moderately small range during the test, so that devices with ordinary resolutions (such as cameras and displays) can also meet the requirements.

[0027] In this embodiment, the biased glasses also have a fogging effect. Children with myopia usually have a strong ability to adjust. Without dilation of the pupil, the ciliary muscle is not easy to relax, and may even spasm, which will cause the measurement result to be high. Because the biased glasses provide undercorrection, compared with full correction, it is equivalent to superimposing a small amount of positive lens on the basis of a myopic negative lens. Using a positive lens to cause fogging to induce ciliary muscle relaxation is a method commonly used in clinical practice. In this system, it is achieved with an undercorrected negative lens.

[0028] In this embodiment, the biased diopter information of the biased glasses is preferably, but not limited to, input into the central controller through an input device for subsequent processing by the central controller. The feedback device is preferably, but not limited to, an operating handle, the operating handle includes a test subject input module and a handle communication module, the test subject input module is preferably, but not limited to, an existing key group key, a touch screen or a voice recognition module, the test subject uses keys, touch, voice dialogue and other methods to feedback the visual mark recognition results, and the visual mark recognition results are preferably, but not limited to, "cannot see clearly", "can see clearly", "letters facing left", "letters facing right". The handle communication module and the central processor can be connected by wire or wirelessly, and the handle communication module is preferably, but not limited to, an existing RS232 serial communication module or RS485 serial communication module or WIFI communication module or Bluetooth module or a radio frequency communication module for remote control.

[0029] In this embodiment, if the historical refractive power of the tested person is small or the refractive power is normal, the lenses of the biased glasses can be set as plano lenses or no lenses are needed.

[0030] In this embodiment, the central controller is connected to the camera for communication to obtain the image captured by the camera. The central controller is used to obtain the distance between the testee and the sight mark according to the front image of the testee output by the camera. The distance between the testee and the sight mark is the distance between the testee and the display. The specific acquisition process of the distance can refer to the technical solution disclosed in the Chinese patent with publication number CN113197542A in the prior art, which will not be repeated here. The central controller can obtain the real-time distance between the sight mark and the testee according to the front image of the testee captured by the camera in real time, and can also obtain the distance between the testee and the sight mark when the testee feeds back the sight mark recognition result, so as to avoid wasting computing resources.

[0031] In this embodiment, the process of the central controller obtaining the diopter test result by combining the distance, the sight mark recognition result and the biased refractive power is as follows: when the sight mark recognition result fed back by the test subject is "can see clearly" or the error rate is less than the error rate threshold, the central controller obtains the distance between the test subject and the sight mark at this time; selects the maximum distance between the test subject and the sight mark when the test subject feeds back "can see clearly" or the error rate is less than the error rate threshold, and the corrected refractive power value of the test subject can be obtained through the maximum distance, and the corrected refractive power value is added to the biased refractive power of the biased glasses to obtain the final refractive power value of the test subject.

[0032] In this embodiment, when the test subject measures the myopia diopter or hyperopia diopter, a letter sight mark is used, and the test subject's corrected diopter value is the reciprocal of the maximum distance, and the corrected equivalent spherical diameter R is obtained as follows: dis represents the maximum distance between the subject and the sight mark when the subject responds "can see clearly". Figure 3 The astigmatism sight mark shown is used to obtain the maximum distance (the distance between the test subject and the sight mark) when the test subject feedbacks that only one stripe can be seen clearly, and the maximum distance (the distance between the test subject and the sight mark) when the test subject feedbacks that all stripes can be seen clearly, and the spherical power after correction of the test subject is obtained. The corrected cylindrical power of the test subject is

[0033] In a preferred embodiment, in order to improve the test accuracy, the central controller includes a sight mark display adjustment module, which adjusts the linear size of the sight mark in the display according to the distance between the test subject and the sight mark, and the sight mark remains unchanged for the human eye. The specific process is:

[0034] The central controller obtains the front image of the subject from the camera in real time, and obtains the real-time distance between the subject and the sight mark based on the front image of the subject;

[0035] When the real-time distance increases, the size of the sight mark displayed on the display is enlarged in the same proportion, and when the real-time distance decreases, the size of the sight mark displayed on the display is reduced in the same proportion.

[0036] In this embodiment, if Figure 4 As shown, no matter how far the test subject is, the angle θ of the letter sight mark to the glasses remains unchanged, and θ is preferably but not limited to 5 arc minutes, which corresponds to 1.0 visual acuity; similar to the letter sight mark, the size change process of the astigmatism sight mark is as follows Figure 5 As shown, the angle of each group of stripes remains constant at different distances. Therefore, when the subject approaches the display screen, the sight mark displayed on the screen is reduced, and when the subject moves back, the sight mark is enlarged.

[0037] In the present embodiment, it is further preferred that, in order to further improve the accuracy of the refractive power test, the sight mark display adjustment module controls the display to first display the white background sight mark. When the test subject feedbacks that he can clearly see the white background sight mark, the display is further controlled to display the red and green background sight marks. The red and green background sight marks are sight marks with red and green backgrounds that appear on the display interface at the same time, so as to determine the refractive power more accurately. When the test subject can see both the red and green background sight marks clearly at the same time or the error rate is less than the error rate threshold, and the sight mark recognition accuracy is the same, it is considered that a precise refractive power test can be performed.

[0038] In a preferred embodiment, in order to speed up data processing, reduce computational complexity and improve distance acquisition accuracy, two spaced marks are provided on the biased glasses, that is, there is a certain distance between the two marks, which is defined as the geographic space distance, and the central controller further includes a distance acquisition module; the distance acquisition module is used to obtain the distance between the subject and the visual mark according to the pixel distance between the two marks in the front image of the subject, the geographic space distance of the two marks and the camera parameters. The camera parameters preferably include, but are not limited to, the field of view of the camera and the number of pixels of resolution.

[0039] In this embodiment, the mark is preferably, but not limited to, a paper label or a color mark. Preferably, the two marks are respectively located on the left and right lenses of the offset glasses so that the two marks can be quickly located and identified in the front image of the test subject. Figure 6 As shown, the geographic space distance between the two marks is W, and the field of view of the camera is V. Then the distance d between the test subject and the sight mark can be obtained according to the following formula: Wherein, Z represents the pixel distance between the two markers, that is, the number of pixels representing the distance between the center points of the two markers in the front image of the subject, and F represents the number of pixels of the camera resolution.

[0040] In this embodiment, it is further preferred that the central controller automatically obtains the biased diopter of the biased glasses to improve efficiency, such as Figure 6 As shown, the biased glasses are provided with an identification mark, which corresponds one-to-one to the biased diopter of the biased glasses. The identification mark is preferably but not limited to a one-dimensional code label or a two-dimensional code label, and the identification mark is associated with the biased diopter of the two lenses of the biased glasses; the central controller includes a biased diopter recognition module, which recognizes the identification mark in the front image of the test subject to obtain the biased diopter of the biased glasses.

[0041] In this embodiment, in order to facilitate the asynchronous replacement of the left and right lenses, and to quickly obtain the offset diopter of each lens, while simplifying the system, it is further preferred that Figure 6 As shown, two marks are respectively arranged on the two lenses of the offset glasses, the left mark is a left identification mark corresponding one-to-one to the offset diopter of the left lens, and the right mark is a right identification mark corresponding one-to-one to the offset diopter of the right lens; the offset diopter recognition module recognizes the two identification marks in the front image of the test subject to obtain the offset diopter of the two lenses.

[0042] In a preferred embodiment, in order to improve the user experience and speed up the test, the central controller includes a distance adjustment module. When the test subject's sight mark recognition result is unclear or the error rate reaches the error rate threshold, the distance adjustment module is used to obtain the test subject's distance adjustment information according to the sight mark display state and the distance between the test subject and the sight mark. The distance adjustment information includes the test subject's moving direction and / or the test subject's moving distance. The moving direction includes forward or backward.

[0043] In this embodiment, the distance adjustment information acquisition process includes: when the current sight mark is a red-green background sight mark, if the subject can only see the green background sight mark or the error rate of the green background sight mark is less than the error rate threshold, the distance adjustment information is: take a step back, and the step distance is dis represents the current distance between the subject and the sight mark obtained by the central controller; if the subject can only see the red background sight mark or the error rate of the red background sight mark is less than the error rate threshold, the distance adjustment information is: move forward one step, and the step length is If the subject can see the red and green background sight marks clearly at the same time or the error rates of the two background sight marks are both less than the error rate threshold, there is no need to adjust the distance; when the current sight mark is not a red or green sight mark, such as a sight mark with black font on a white background, if the feedback is that the sight mark cannot be seen clearly or the sight mark recognition error rate is less than the error rate threshold, the distance adjustment information is: take one step forward.

[0044] In this embodiment, preferably, in order to improve the user experience, the distance adjustment information is notified to the test subject through voice prompts or display.

[0045] In a preferred embodiment, in order to make the subject move within a suitable distance range, speed up the test speed, and improve the measurement accuracy, the central controller further includes an initial distance acquisition module, which is used to set the initial distance of the subject from the sight mark according to the historical refraction of the subject, specifically including:

[0046] When the person under test is measured without bias, for example, his historical refractive power is unknown or he has no historical refractive power, the initial distance is set to L meters, and the value range of L is 1.8-2.1, preferably, L is 2;

[0047] When the historical refraction of the person being tested is known and the biased glasses they wear have a biased refraction, the initial distance is set to:

[0048]

[0049] Wherein, R0 represents the historical refractive value, and floor(·) represents the floor rounding function.

[0050] In a preferred embodiment, in order to improve the user experience and speed up the test, the central controller also includes a position indication module, which is used to display a real-time position display area on the controller display, and the real-time position display area displays the virtual image of the test subject, the destination position, and dynamically updates the distance between the test subject and the destination position. The destination position is preferably, but not limited to, the initial distance position or the position corresponding to the distance adjustment information during the test. Specifically, Figure 7 As shown, different patterns or colors are used to indicate whether there is still a gap between the subject's current position and the target position, or whether it is just right. Based on the real-time feedback of the graphic, the subject can clearly know how much to move forward or backward. Figure 7 In the figure, area A represents the destination, point B represents the current location of the subject, area C represents the interval beyond the destination, and point D represents the starting point of the movement.

[0051] In this embodiment, preferably, in an application scenario, the position indicating device includes a column of indicator lights installed on the ground. The specific installation method may be to set a mounting hole on the ground, and the indicator lights are installed in the mounting hole at a height lower than the ground. The column of indicator lights extends forward from the display, and the central controller includes a lighting control module. The working process of the lighting control module is as follows: after obtaining the initial distance, the lighting control module controls the indicator lights whose distance from the display is the initial distance or close to the initial distance to light up, and the other indicator lights are off; after obtaining the distance adjustment information, the previous or next indicator light whose distance from the currently lit indicator light is the same as or close to the step distance is controlled according to the distance adjustment information to light up, and the other indicator lights are off.

[0052] In this embodiment, preferably, in another application scenario, the position indicating device includes a marking laser and a servo for driving the marking laser to rotate, the marking laser outputs a point light spot or a line light spot, the central controller includes a servo control module, and the working process of the servo control module is: assuming that the distance between the test subject and the display is a first distance, and establishing a corresponding relationship between the servo rotation angle and the first distance; after obtaining the initial distance, the servo control module controls the servo to rotate, and its rotation angle corresponds to the initial distance; after obtaining the distance adjustment information, the servo is controlled to rotate forward or reverse by an angle increment based on the current rotation angle according to the distance adjustment information, and the size of the angle increment corresponds to the step size.

[0053] In one application scenario of the intelligent self-service diopter measurement system provided in this application, the diopter test process includes:

[0054] Step S1, setting an initial distance, the subject stands at the initial distance, and at the same time, a front image of the subject is captured by a camera, and the distance between the subject and the display is obtained based on the front image, and set as a first distance, and determining whether the first distance is the same as the initial distance, and if not, prompting the subject to adjust;

[0055] Step S2: If the subject can clearly see the sight mark on the display at the initial distance, it indicates that there is no refractive error (if the subject wears biased glasses, the refractive error is considered to be the biased diopter), and no further testing is required. If the subject cannot see clearly, proceed to step S3;

[0056] Step S3: If the test subject cannot see clearly or the error rate is greater than the error rate threshold starting from the initial distance, the test subject is prompted to move closer to the display until the display is clear or the error rate is less than the error rate threshold, and the first distance at this time is obtained, and the refractive error, i.e., the diopter value, is calculated based on the first distance. If further fine adjustment is required, proceed to step S4;

[0057] Step S4, switch the sight mark to the red and green background sight mark, obtain distance adjustment information according to the recognition result fed back by the test subject, and adjust the distance until the red and green background sight marks can be seen clearly at the same time, obtain the first distance at this time, and obtain the refractive error, that is, the diopter value, according to the first distance.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0059] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An intelligent self-service diopter measurement system, characterized in that: include: An optotype display device, used for displaying optotypes to the test subject; A camera, used to capture a frontal image of the person being tested; Biased glasses, providing biased diopter for the person being tested, wherein the biased diopter is determined based on the historical diopter of the person being tested; Feedback device, through which the test subject feeds back the visual mark recognition result to the central controller; The central controller is used to obtain the distance between the test subject and the sight mark according to the front image of the test subject output by the camera, and obtain the diopter test result by combining the distance, the sight mark recognition result and the offset diopter; The central controller includes a distance adjustment module. When the testee's sight mark recognition result is unclear or the error rate reaches an error rate threshold, the distance adjustment module is used to obtain the testee's distance adjustment information according to the sight mark display state and the distance between the testee and the sight mark. The distance adjustment information includes the testee's moving direction and / or the testee's moving distance. The central controller further includes an initial distance acquisition module, which is used to set an initial distance between the testee and the sight mark according to the testee's historical diopter, wherein when the testee is measured without bias, the testee's historical diopter cannot be known or the testee has no historical diopter, and the initial distance is set to L meters, and the value range of L is 1.8-2.1; When the historical refraction of the person being tested is known and the biased glasses they wear have a biased refraction, the initial distance is set to: Wherein, R0 represents the historical refractive value, and floor(·) represents the floor rounding function.

2. The intelligent self-service diopter measurement system according to claim 1, characterized in that: The sight mark display device is a display, and the display is connected to the central controller; The display is used to display an optotype, or the display is used to display an optotype and an operation instruction.

3. The intelligent self-service diopter measurement system according to claim 2, characterized in that: The central controller comprises an optotype display adjustment module, which adjusts the linear size of the optotype in the display according to the distance between the tested person and the optotype, and the opening angle of the optotype to the human eye remains unchanged.

4. The intelligent self-service diopter measurement system according to claim 3, characterized in that: The optotype display adjustment module controls the display to first display the white background optotype, and when the tested person feedbacks that he can see the white background optotype clearly, controls the display to display the red and green background optotypes.

5. The intelligent self-service refractive power measurement system according to any one of claims 1 to 4, characterized in that: The biased glasses are provided with two spaced marks, and the central controller further comprises a distance acquisition module; The distance acquisition module is used to obtain the distance between the test subject and the visual mark according to the pixel distance between the two marks in the front image of the test subject, the geographic space distance between the two marks and the camera parameters.

6. The intelligent self-service diopter measurement system according to claim 5, characterized in that: The offset glasses are provided with identification marks, and the identification marks correspond one to one with the offset diopter of the offset glasses; The central controller comprises a biased diopter recognition module, which recognizes a recognition mark in the front image of the tested person to obtain the biased diopter of the biased glasses.

7. The intelligent self-service diopter measurement system according to claim 6, characterized in that: Two marks are respectively set on the two lenses of the offset glasses, the left mark is a left identification mark corresponding to the offset diopter of the left lens, and the right mark is a right identification mark corresponding to the offset diopter of the right lens; The offset diopter recognition module recognizes two recognition marks in the front image of the test subject to obtain the offset diopter of the two lenses.

8. The intelligent self-service diopter measurement system according to claim 1, characterized in that: The central controller also includes a position indication module, which is used to control the display of the controller to display a real-time position display area, wherein the real-time position display area displays the virtual image of the test subject, the destination position, and dynamically updates the distance between the test subject and the destination position.

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