Automatic focusing type lensometer and diopter and axial position measuring method

Abstract

The invention relates to the field of lens detection, in particular to an automatic focusing type lensometer and a diopter and axial position measuring method.The automatic focusing type lensometer comprises a rack and further comprises a lighting source, an axial position adjusting assembly, a focusing assembly, a lens support, an imaging assembly and an industrial personal computer which are installed on the rack, and a corneal contact lens is placed on the lens support; the axial position adjusting assembly comprises a reticle and an axial position driving mechanism for driving the reticle to rotate; the focusing assembly comprises a focusing lens group and a focusing driving mechanism for driving the focusing lens group to move; the imaging assembly comprises an imaging lens group and a camera; the industrial personal computer is used for controlling the focusing driving mechanism and the axial position driving mechanism and calculating the diopter and the axial position of the corneal contact lens. According to the invention, the automatic adjustment of the focusing amount and the axial position can be realized, the clearest position of the projection pattern is searched through a machine vision algorithm, the reading error caused by manual interpretation is avoided, and the repeated measurement precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lens detection, and in particular relates to an automatic focusing focimeter and a diopter and axial position measurement method. Background Art

[0002] A focalometer is a measuring instrument for measuring contact lenses, which is mainly divided into two types. One is a manual focus focalometer. The operator places the contact lens in the test area, and then manually rotates the focus wheel and the axis wheel until the image on the projection glass is clearest. At this time, the refractive power and axis position of the contact lens can be calculated based on the position change of the focus wheel and the axis wheel. The disadvantage of the manual focus focalometer is that the focus wheel and the axis wheel need to be manually operated. Whether the projection pattern is clear or not depends on subjective judgment. Different people have different feelings about when the projection pattern is clearest. Even the same person has different feelings at different times, which will cause large human errors. Moreover, due to the optical principle of projection measurement, the operator is equivalent to looking directly at the light source, which will irritate the operator's eyes when working for a long time. The other is an automatic focus focalometer, which calculates the amount of light deflection based on the Hartmann principle, and can directly obtain the refractive power and axis position of the contact lens. The disadvantage of an autofocus focalometer is that it does not have an intuitive graticule projection pattern and can only measure the refractive power and axial position of the contact lens. It cannot judge the imaging quality of the contact lens. For example, if there are defects such as bubbles and contamination on the contact lens, the autofocus focalometer cannot detect these problems. Summary of the invention

[0003] In view of this, the present invention aims to provide an automatic focusing focimeter and a method for measuring diopter and axial position, so as to solve the technical problem that the manual focusing focimeter has large errors in the detection results due to subjective judgment, and the automatic focusing focimeter cannot judge the imaging quality of corneal contact lenses.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows: An automatic focusing focal meter comprises a frame and an illumination light source, an axis position adjustment component, a focusing component, a lens support, an imaging component and an industrial computer installed on the frame in sequence according to the light propagation direction; wherein, The contact lens is placed on the lens holder; The axial position adjustment assembly includes a reticle and an axial position driving mechanism for driving the reticle to rotate; The focusing assembly includes a focusing lens group and a focusing driving mechanism for driving the focusing lens group to move; The imaging component includes an imaging lens group and a camera; The industrial computer is used to control the focusing drive mechanism and the axial position drive mechanism respectively, and calculate the refractive power and axial position of the corneal contact lens.

[0005] Furthermore, the axial drive mechanism includes an axial motor, an axial driving gear, an axial driven gear, an axial adjustment gear, a graticule mounting seat, an axial encoder, an axial motor fixing plate and an axial encoder fixing plate. The axial motor is fixed to the frame through the axial motor fixing plate, the axial encoder is fixed to the frame through the axial encoder fixing plate, the axial driving gear is sleeved on the output shaft of the axial motor, the axial driven gear is sleeved on the rotating shaft of the axial encoder, the graticule is mounted on the graticule mounting seat, the graticule mounting seat is fixed on one side of the axial adjustment gear, and the axial adjustment gear and the axial driven gear are both meshed with the axial driving gear for transmission.

[0006] Furthermore, the focusing drive mechanism includes a focusing motor, a focusing motor fixing plate, a coupling, a transmission shaft, a bevel gear, a bevel rack, a sliding plate, a focusing active gear, a focusing driven gear, a focusing encoder and a focusing encoder fixing plate. The focusing motor is fixed to the frame through the focusing motor fixing plate, the focusing encoder is fixed to the frame through the focusing encoder fixing plate, the output shaft of the focusing motor is connected to one end of the transmission shaft through a coupling, the focusing active gear is sleeved on the other end of the transmission shaft, the focusing driven gear is sleeved on the rotating shaft of the focusing encoder and meshes with the focusing active gear for transmission, the bevel gear is sleeved in the middle position of the transmission shaft and meshes with the bevel rack for transmission, the bevel rack is fixed to one side of the sliding plate, and the focusing lens group is fixed to the other side of the sliding plate through a connecting plate.

[0007] Furthermore, the focusing drive mechanism also includes a linear guide rail, which includes a guide rail and a slider. The guide rail is fixedly connected to the frame, and the slider slides on the slide rail and is fixedly connected to a side of the sliding plate away from the bevel rack.

[0008] Furthermore, the automatic focusing focal meter also includes a display screen and a touch screen, the touch screen and the display screen are respectively connected to the industrial computer, the touch screen is used to realize human-computer interaction, and the display screen is used to display the camera's imaging of the corneal contact lens.

[0009] A method for measuring diopter and axial position using the above-mentioned automatic focusing focal meter, when only the back vertex power of a corneal contact lens is measured, comprises the following steps: A1: Place the contact lens on the autofocus lens holder; A2: The industrial computer controls the focus motor to return to the negative limit position, and controls the axis motor to return to the 0 degree position; A3: The industrial computer controls the camera to collect images of the contact lens and calculates the sharpness value of a crosshair position on the reticle in the image; A4: The industrial computer controls the focus motor to move from the negative limit position to the positive limit position at high speed, and records the focus motor position and sharpness value at the same time, and obtains the relationship between the sharpness value and the focus motor position. When the sharpness value is the maximum value, the position P1 corresponding to the focus motor is the rough value of the back vertex focal length; A5: The industrial computer controls the focus motor to move from the positive limit position at high speed to the position of P1+10% of the total stroke of the focus motor, and then controls the focus motor to move at low speed to the position of P1-10% of the total stroke of the focus motor to obtain the relationship between the sharpness value and the position of the focus motor. When the sharpness value is the maximum value, the position P2 corresponding to the focus motor is the accurate value of the back vertex focal length measurement; When simultaneously measuring the posterior vertex power, cylindrical power and axis position of a corneal contact lens, the following steps are included: B1: Place the contact lens on the autofocus lens holder; B2: The industrial computer controls the focus motor to return to the negative limit position and controls the axis motor to return to the 0 degree position; B3: The industrial computer controls the camera to collect the image of the contact lens and calculates the sharpness value of a crosshair position on the reticle in the image; B4: The industrial computer controls the shaft motor to rotate from the negative angle position to the positive angle position at a preset stepping interval. During each rotation of the shaft motor, the industrial computer controls the focus motor to move from the limit position to the positive limit position at high speed, thereby obtaining the relationship between the sharpness value and the focus motor position at each shaft position. , is the sharpness value, is the axis position, is the focus motor position; when At maximum, get the rough position of the axis and focus motor , ; B5: , The total stroke of the focus motor is range, the focus motor moves at low speed, the stepping interval of the axis motor is 0.5 degrees, repeat step B4 to measure the precise position of the axis and the focus motor , ; B6: In the axial position, repeat A4 and A5 to measure the sharpness value of another crosshair position on the reticle to obtain the focus motor position when the sharpness value is maximum. , then the back vertex power of the contact lens is , cylindrical power , the axis position is .

[0010] Furthermore, the sharpness value is calculated as follows: Assume the image size is x×y pixels and the difference calculation range is m×n pixels, then the sharpness difference value is ,in is the RGB channel value of the pixel at xy, is the RGB channel value of the pixel at x+i, y+j, and After that, Sum the RGB channel values ​​to get the sharpness value.

[0011] Furthermore, when the precise position of the focus motor is obtained, the back vertex power value of the corneal contact lens is obtained according to the pre-calibrated linear relationship between the back vertex power value and the position of the focus motor.

[0012] Furthermore, the high-speed movement of the focus motor is 80° / s, and the low-speed movement of the focus motor is 28° / s.

[0013] Compared with the prior art, the invention can achieve the following beneficial effects: (1) Realize the automated measurement of the refractive power and axis position of corneal contact lenses, avoid subjective human interpretation errors, make the measurement results more accurate, and increase the measurement efficiency; (2) While automatically measuring the refractive power and axis position of the contact lens, the projection pattern of the contact lens captured by the camera can be displayed in real time, making it easier to observe whether there are any defects in the contact lens; (3) The operator only needs to observe the display screen and does not need to look directly at the lighting source for a long time, which protects the operator's eyesight. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 is a schematic structural diagram of an automatic focusing focalometer according to an embodiment of the present invention; Figure 2 It is a structural schematic diagram of the axial drive mechanism according to an embodiment of the invention; Figure 3 is a structural schematic diagram of a focus drive mechanism according to an embodiment of the invention; Figure 4a-4c It is a schematic diagram of the measurement effect of the back vertex power according to the embodiment of the invention; Figure 5a-5c It is a schematic diagram of the change of the sharpness value calculation position with the axis position according to the embodiment of the invention.

[0015] The reference numerals therein include: frame 1, illumination light source 2, axial position adjustment assembly 3, graticule 301, axial position motor 302, axial position driving gear 303, axial position driven gear 304, axial position adjustment gear 305, graticule mounting seat 306, axial position encoder 307, axial position motor fixing plate 308, axial position encoder fixing plate 309, focusing assembly 4, focusing lens group 401, focusing motor 402, focusing motor fixing plate 403, coupling 404, transmission shaft 405, bevel gear 406, bevel rack 407, sliding plate 408, focusing driving gear 409, focusing driven gear 410, focusing encoder 411, focusing encoder fixing plate 412, linear guide 413, lens support 5, imaging assembly 6, industrial computer 7, display screen 8, touch screen 9, angle adjustment bracket 10. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships 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. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0020] The following will refer to Figure 1 - Figure 5 and embodiments are used to illustrate the invention in detail.

[0021] like Figure 1-Figure 3 As shown, the automatic focusing focal meter provided by the embodiment of the invention comprises a frame 1 and an illumination light source 2, an axial position adjustment component 3, a focusing component 4, a lens support 5, an imaging component 6, and an industrial computer 7, a display screen 8 and a touch screen 9 installed on the frame 1 in sequence according to the light propagation direction; wherein the corneal contact lens is placed on the lens support 5; the axial position adjustment component 3 comprises a graticule 301 and an axial position driving mechanism for driving the graticule 301 to rotate, and the graticule 301 has two crosshairs for calculating the diopter and axial position of the corneal contact lens; the focusing component 4 comprises a focusing lens group 401 and A focusing drive mechanism drives the focusing lens group 401 to move; the imaging component 6 includes an imaging lens group and a camera, the imaging lens group is used to realize imaging of the corneal contact lens, and the camera is used to collect images of the corneal contact lens; the industrial computer 7 is used to control the focusing drive mechanism and the axial drive mechanism respectively, and calculate the refractive power and axial position of the corneal contact lens, the display screen 8 and the touch screen 9 are respectively connected to the industrial computer 7, the display screen 8 is installed on the frame 1 through the angle adjustment bracket 10, and is used to realize human-computer interaction, trigger measurement instructions by operating the touch screen, and display the image collected by the camera, and the display screen 8 is used to display the collected image.

[0022] The images captured by the camera can be displayed on the small screen of the touch screen 9, and can also be displayed on the larger display screen 8, so that more people can watch them.

[0023] The axial drive mechanism 3 includes an axial motor 302, an axial driving gear 303, an axial driven gear 304, an axial adjustment gear 305, a grating plate mounting seat 306, an axial encoder 307, an axial motor fixing plate 308, and an axial encoder fixing plate 309. The axial motor 302 is fixed to the frame 1 through the axial motor fixing plate 308, and the axial encoder 307 is fixed to the frame 1 through the axial encoder fixing plate 309. The axial driving gear 303 is sleeved on the output shaft of the axial motor 302, and the axial driven gear 304 is sleeved on the rotating shaft of the axial encoder 307. The grating plate 301 is mounted on the grating plate mounting seat 306, and the grating plate mounting seat 306 is fixed to one side of the axial adjustment gear 305. The axial adjustment gear 305 and the axial driven gear 304 are both meshed with the axial driving gear 303 for transmission.

[0024] The axial motor 302 drives the axial driving gear 303 to rotate, the axial driving gear 303 drives the axial driven gear 304 and the axial adjustment gear 305 to rotate, the axial driven gear 304 drives the axial encoder 307 to rotate, and the axial adjustment gear 305 drives the dividing plate 301 to rotate, and finally the image displayed on the display screen 8 and the touch screen 9 rotates, thereby achieving the purpose of adjusting the axial position.

[0025] When measuring the axial position of the contact lens, the contact lens is placed on the lens holder 5, and the illumination light source 2 emits illumination light, which passes through the contact lens of the graticule 301, the focusing lens group 401, and the imaging lens group in sequence, and finally forms an image on the target surface of the camera, which is displayed on the display screen 8 and the touch screen 9 through the industrial computer 7. By operating the touch screen 9, an axial position measurement instruction is issued, and the axial position adjustment is driven by the axial position motor 302. From the image collected by the camera, the position where the image is clearest is determined, and the position of the axial position motor 302 when the image is clearest is fed back through the code value of the axial position encoder 307, thereby calculating the axial position of the contact lens.

[0026] The focus driving mechanism includes a focus motor 402, a focus motor fixing plate 403, a coupling 404, a transmission shaft 405, a bevel gear 406, a bevel rack 407, a sliding plate 408, a focus driving gear 409, a focus driven gear 410, a focus encoder 411, a focus encoder fixing plate 412 and a linear guide 413. The focus motor 402 is fixed to the frame 1 through the focus motor fixing plate 403, the focus encoder 411 is fixed to the frame 1 through the focus encoder fixing plate 412, and the focus motor 402 is fixed to the frame 1 through the focus encoder fixing plate 412. The output shaft of the machine 402 is connected to one end of the transmission shaft 405 through a coupling 404, the focusing active gear 409 is sleeved on the other end of the transmission shaft 405, the focusing driven gear 410 is sleeved on the rotating shaft of the focusing encoder 411 and meshes with the focusing active gear 409 for transmission, the bevel gear 406 is sleeved on the middle position of the transmission shaft 405 and meshes with the bevel rack 407 for transmission, the bevel rack 407 is fixed on one side of the sliding plate 408, and the focusing lens group 401 is fixed on the other side of the sliding plate 408 through a connecting plate.

[0027] The linear guide rail 413 includes a guide rail and a slider, the guide rail is fixedly connected to the frame 1, and the slider slides on the guide rail and is fixedly connected to the side of the sliding plate 408 away from the bevel rack. The linear guide rail 413 is used to ensure the linearity of the up and down movement of the sliding plate 408, thereby ensuring the focusing effect of the focusing lens group 401.

[0028] The transmission shaft 405 is driven to rotate by the focusing motor 402, and the transmission shaft 405 drives the bevel gear 406 and the focusing driving gear 409 to rotate, and the focusing driving gear 409 drives the focusing driven gear 410 to rotate, thereby driving the focusing encoder 411 to rotate, and the bevel gear 406 drives the sliding plate 408 to move up and down, thereby driving the focusing lens group 401 to move up and down to achieve focusing.

[0029] When measuring the diopter of the contact lens, the contact lens is placed on the lens holder 5, and the illumination light source 2 emits illumination light, which passes through the contact lens, the focusing lens group, and the imaging lens group in sequence on the graticule 301, and finally forms an image on the camera target surface, which is displayed on the display screen 8 and the touch screen 9 through the industrial computer 7. By operating the touch screen 9, a diopter measurement instruction is issued, and the focusing motor 402 drives the focusing, and the camera is photographed through the full stroke. After all images are collected, the algorithm of the industrial computer 7 determines the position of the clearest image, and the focusing motor 402 rotates to this position to obtain the clearest image. The position of the focusing motor 402 when the image is clearest is fed back through the focusing encoder 411, and the vertex value corresponding to the position is calculated.

[0030] The above content describes in detail the structure of the automatic focusing focalometer provided by the embodiment of the invention. Corresponding to the automatic focusing focalometer, the embodiment of the invention also provides a method for measuring diopter and axial position using the automatic focusing focalometer. The diopter includes the back vertex focal power (myopia degree) and the cylindrical focal power (astigmatism degree), and the axial position is also called the astigmatism axial position. The measuring method of the invention can measure only the back vertex focal power of the corneal contact lens, and can also measure the back vertex focal power, cylindrical focal power and axial position of the corneal contact lens at the same time.

[0031] When only the back vertex power of a contact lens is measured, the following steps are involved: A1: Place the contact lens on the autofocus power lens holder.

[0032] The operator starts the measurement by tapping the touch screen.

[0033] A2: The industrial computer controls the focus motor to return to the negative limit position and controls the axis motor to return to the 0 degree position.

[0034] A3: The industrial computer controls the camera to collect the image of the contact lens and calculates the sharpness value of a crosshair position on the reticle in the image.

[0035] A4: The industrial computer controls the focus motor to move from the negative limit position to the positive limit position at high speed, and records the focus motor position and sharpness value at the same time to obtain the relationship between the sharpness value and the focus motor position. When the sharpness value is the maximum value, the position P1 corresponding to the focus motor is the rough value of the back vertex focal length.

[0036] The sharpness value is calculated as follows: Assume the image size is x×y pixels and the difference calculation range is m×n pixels, then the sharpness difference value is ,in is the RGB channel value of the pixel at x, y, is the RGB channel value of the pixel at x+i, y+j, for example, P(101 201)=(128 0 255) refers to the pixel (101 201) has RGB channel values ​​of 128, 0, and 255. After that, The sharpness value is obtained by summing the RGB channel values, that is, adding the values ​​of the three RGB channels to obtain the sharpness value.

[0037] The high-speed movement of the focus motor is 80° / s, and the low-speed movement of the focus motor is 28° / s.

[0038] Since the back vertex focal value in the focal meter is linearly related to the position of the focusing motor, the corresponding relationship between the back vertex focal value and the position of the focusing motor can be obtained through calibration in advance. Therefore, what is actually measured during measurement is the position of the focusing motor. The back vertex focal value of the corneal contact lens is then obtained through the corresponding relationship between the back vertex focal value and the position of the focusing motor.

[0039] like Figure 4a-4c As shown, the measurement effect of the back vertex power is Figure 4a-4c The order is clear, relatively fuzzy, and very fuzzy. Figure 4a-4c The yellow box in the middle is the area where the sharpness value is calculated. Figure 4a-4c The calculated sharpness values ​​are 81930, 36080, and 19526 respectively. The greater the sharpness, the clearer it is.

[0040] A5: The industrial computer controls the focus motor to move from the positive limit position at high speed to the position of P1+10% of the total stroke of the focus motor, and then controls the focus motor to move at low speed to the position of P1-10% of the total stroke of the focus motor to obtain the relationship between the sharpness value and the focus motor position. When the sharpness value is the maximum value, the position P2 corresponding to the focus motor is the accurate value of the back vertex focal length measurement.

[0041] When simultaneously measuring the posterior vertex power, cylindrical power and axis position of a corneal contact lens, the following steps are included: B1: Place the contact lens on the autofocus power lens holder.

[0042] B2: The industrial computer controls the focus motor to return to the negative limit position and controls the axis motor to return to the 0 degree position.

[0043] B3: The industrial computer controls the camera to collect the image of the corneal contact lens and calculates the sharpness value of a crosshair position on the graticule in the image.

[0044] B4: The industrial computer controls the shaft motor to rotate from the negative angle position to the positive angle position at a preset stepping interval. During each rotation of the shaft motor, the industrial computer controls the focus motor to move from the limit position to the positive limit position at high speed, thereby obtaining the relationship between the sharpness value and the focus motor position at each shaft position. , is the sharpness value, is the axis position, is the focus motor position; when At maximum, get the rough position of the axis and focus motor , .

[0045] B5: , The total stroke of the focus motor is range, the focus motor moves at low speed, the stepping interval of the axis motor is 0.5 degrees, repeat step B4 to measure the precise position of the axis and the focus motor , .

[0046] B6: In the axial position, repeat A4 and A5 to measure the sharpness value of another crosshair position on the reticle to obtain the focus motor position when the sharpness value is maximum. , then the back vertex power of the contact lens is , cylindrical power , the axis position is .

[0047] like Figure 5a-5c As shown, Figure 5a The calculation area of ​​the sharpness value at the 30-degree axis position; Figure 5b The calculation area of ​​the sharpness value at the axis position of -10 degrees; Figure 5c After determining the axis position, another area is used to calculate the sharpness value of the crosshairs.

[0048] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0049] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An automatic focusing focimeter, characterized in that: It includes a frame and an illumination light source, an axis adjustment component, a focusing component, a lens support, an imaging component and an industrial computer installed on the frame in sequence according to the light propagation direction; wherein, The contact lens is placed on the lens holder; The axial position adjustment assembly includes a reticle and an axial position driving mechanism for driving the reticle to rotate; The focusing assembly includes a focusing lens group and a focusing driving mechanism for driving the focusing lens group to move; The imaging component includes an imaging lens group and a camera; The industrial computer is used to control the focusing drive mechanism and the axial drive mechanism respectively, and calculate the refractive power and axial position of the corneal contact lens.

2. The automatic focusing focimeter according to claim 1, characterized in that: The axial drive mechanism includes an axial motor, an axial driving gear, an axial driven gear, an axial adjustment gear, a graticule mounting seat, an axial encoder, an axial motor fixing plate and an axial encoder fixing plate. The axial motor is fixed to the frame through the axial motor fixing plate, the axial encoder is fixed to the frame through the axial encoder fixing plate, the axial driving gear is sleeved on the output shaft of the axial motor, the axial driven gear is sleeved on the rotating shaft of the axial encoder, the graticule is mounted on the graticule mounting seat, the graticule mounting seat is fixed on one side of the axial adjustment gear, and the axial adjustment gear and the axial driven gear are both meshed with the axial driving gear for transmission.

3. The automatic focusing focimeter according to claim 2, characterized in that: The focusing drive mechanism includes a focusing motor, a focusing motor fixing plate, a coupling, a transmission shaft, a bevel gear, a bevel rack, a sliding plate, a focusing active gear, a focusing driven gear, a focusing encoder and a focusing encoder fixing plate. The focusing motor is fixed to the frame through the focusing motor fixing plate, the focusing encoder is fixed to the frame through the focusing encoder fixing plate, the output shaft of the focusing motor is connected to one end of the transmission shaft through a coupling, the focusing active gear is sleeved on the other end of the transmission shaft, the focusing driven gear is sleeved on the rotating shaft of the focusing encoder and meshes with the focusing active gear for transmission, the bevel gear is sleeved on the middle position of the transmission shaft and meshes with the bevel rack for transmission, the bevel rack is fixed to one side of the sliding plate, and the focusing lens group is fixed to the other side of the sliding plate through a connecting plate.

4. The automatic focusing focimeter according to claim 3, characterized in that: The focusing drive mechanism also includes a linear guide rail, which includes a guide rail and a sliding block. The guide rail is fixedly connected to the frame, and the sliding block slides on the slide rail and is fixedly connected to a side of the sliding plate away from the bevel rack.

5. The automatic focusing focimeter according to claim 1, characterized in that: It also includes a display screen and a touch screen. The touch screen and the display screen are respectively connected to the industrial computer. The touch screen is used to realize human-computer interaction, and the display screen is used to display the camera's imaging of the corneal contact lens.

6. A method for measuring diopter and axial position using the automatic focusing focal meter according to claim 3, characterized in that: When only the back vertex power of a contact lens is measured, the following steps are involved: A1: Place the contact lens on the autofocus lens holder; A2: The industrial computer controls the focus motor to return to the negative limit position, and controls the axis motor to return to the 0 degree position; A3: The industrial computer controls the camera to collect images of the contact lens and calculates the sharpness value of a crosshair position on the reticle in the image; A4: The industrial computer controls the focus motor to move from the negative limit position to the positive limit position at high speed, and records the focus motor position and sharpness value at the same time, and obtains the relationship between the sharpness value and the focus motor position. When the sharpness value is the maximum value, the position P1 corresponding to the focus motor is the rough value of the back vertex focal length; A5: The industrial computer controls the focus motor to move from the positive limit position at high speed to the position of P1+10% of the total stroke of the focus motor, and then controls the focus motor to move at low speed to the position of P1-10% of the total stroke of the focus motor to obtain the relationship between the sharpness value and the position of the focus motor. When the sharpness value is the maximum value, the position P2 corresponding to the focus motor is the accurate value of the back vertex focal length measurement; When simultaneously measuring the posterior vertex power, cylindrical power and axis position of a corneal contact lens, the following steps are included: B1: Place the contact lens on the autofocus lens holder; B2: The industrial computer controls the focus motor to return to the negative limit position and controls the axis motor to return to the 0 degree position; B3: The industrial computer controls the camera to collect the image of the contact lens and calculates the sharpness value of a crosshair position on the reticle in the image; B4: The industrial computer controls the shaft motor to rotate from the negative angle position to the positive angle position at a preset stepping interval. During each rotation of the shaft motor, the industrial computer controls the focus motor to move from the limit position to the positive limit position at high speed, thereby obtaining the relationship between the sharpness value and the focus motor position at each shaft position. , is the sharpness value, is the axis position, is the focus motor position; when At maximum, get the rough position of the axis and focus motor , ; B5: , The total stroke of the focus motor is range, the focus motor moves at low speed, the stepping interval of the axis motor is 0.5 degrees, repeat step B4 to measure the precise position of the axis and the focus motor , ; B6: In the axial position, repeat A4 and A5 to measure the sharpness value of another crosshair position on the reticle to obtain the focus motor position when the sharpness value is maximum. , then the back vertex power of the contact lens is , cylindrical power , the axis position is .

7. The method for measuring diopter and axis position according to claim 6, characterized in that: The sharpness value is calculated as follows: Assume the image size is x×y pixels and the difference calculation range is m×n pixels, then the sharpness difference value is ,in is the RGB channel value of the pixel at x, y, is the RGB channel value of the pixel at x+i, y+j, and After that, Sum the RGB channel values ​​to get the sharpness value.

8. The method for measuring diopter and axis position according to claim 6, characterized in that: When the precise position of the focus motor is obtained, the back vertex power value of the corneal contact lens is obtained according to the linear relationship between the pre-calibrated back vertex power value and the position of the focus motor.

9. The method for measuring diopter and axis position according to claim 6, characterized in that: The high-speed movement of the focus motor is 80° / s, and the low-speed movement of the focus motor is 28° / s.

Images