An optical lens thickness precision measuring device

Abstract

The present application relates to the technical field of optical lens detection, and particularly to an optical lens thickness accurate measurement device, comprising a rack, at least one set of placing tables are arranged on the rack to place the to-be-detected lenses; a first adjusting mechanism, the number of the first adjusting mechanism is consistent with the placing tables, each set of the first adjusting mechanism is arranged above the placing table one by one, the first adjusting mechanism comprises a mounting frame mounted on the rack, the mounting frame is slidably connected with a sliding frame, a first driving element is mounted on the mounting frame, the first driving element drives the sliding frame to slide in the vertical direction along the mounting frame, and the sliding frame is fixedly connected with a first mounting element; a second adjusting mechanism, the number of the second adjusting mechanism is consistent with the first adjusting mechanism, each set of the second adjusting mechanism is mounted on the mounting frame of the first adjusting mechanism, the second adjusting mechanism comprises a second mounting element capable of sliding relative to the first mounting element and a second driving element driving the second mounting element; a probe is mounted on the second mounting element, and the present application has the effects of high precision, high efficiency and high safety.

Description

Technical Field

[0001] This invention relates to the technical field of optical lens inspection, and in particular to a device for accurately measuring the thickness of optical lenses. Background Technology

[0002] In fields such as precision optics, consumer electronics, medical devices, and high-end instrument manufacturing, the performance of optical lenses directly determines the imaging quality and system stability of the final product. Among these, the center thickness, edge thickness, and overall thickness uniformity of the lens are core geometric parameters. Accurate measurement of these parameters is a crucial step in ensuring the realization of optical designs, quality control, and optimization of manufacturing processes.

[0003] Traditional methods for measuring the thickness of optical lenses mainly rely on contact thickness gauges or non-contact optical interferometers. However, these methods have the following problems in practical applications:

[0004] Traditional contact thickness gauges typically use a single drive mechanism for probe feeding, making it difficult to balance rapid positioning and precise measurement. Relying solely on a high reduction ratio mechanism to achieve micron-level accuracy significantly reduces measurement speed, impacting inspection efficiency. Conversely, relying solely on rapid feeding makes the lens susceptible to damage or measurement errors due to probe impact, especially with high-precision aspherical or coated lenses. The rigid contact method of traditional thickness gauges is also prone to lens surface damage due to excessive probe pressure or positioning deviations, affecting product yield. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a high-precision, high-efficiency, and high-safety optical lens thickness measurement device.

[0006] The above-mentioned objective of this invention is achieved through the following technical solutions: An optical lens thickness precision measurement device includes: a frame, on which are mounted: At least one placement stage is provided for placing the lens to be inspected; The number of first adjustment mechanisms is the same as that of the placement platform. Each group of first adjustment mechanisms is arranged one-to-one above the placement platform. The first adjustment mechanism includes a mounting frame mounted on the frame. A sliding frame is slidably connected to the mounting frame. A first driving component is mounted on the mounting frame. The first driving component drives the sliding frame to slide along the mounting frame in the vertical direction. The sliding frame is fixedly connected to the first mounting component. The number of second adjustment mechanisms is the same as that of the first adjustment mechanisms. Each group of second adjustment mechanisms is installed one-to-one with the mounting bracket of the first adjustment mechanism. The second adjustment mechanism includes a second mounting member that can slide relative to the first mounting member and a second driving member that drives the second mounting member. The probe is mounted on the second mounting component.

[0007] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the mounting frame includes an upper mounting plate and a lower mounting plate located at both ends. A first side plate and a second side plate are connected between the upper mounting plate and the lower mounting plate. A sliding space for a sliding frame is formed between the first side plate and the second side plate. The first driving member is mounted on the first side plate. A guide rail is provided on the side of the second side plate facing the first side plate. The sliding frame slides in cooperation with the guide rail.

[0008] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the output end of the first driving member is connected to a first driving wheel, a first driven wheel is rotatably connected to the mounting bracket, a first synchronous belt is wound between the first driving wheel and the first driven wheel, and the sliding bracket is fixedly connected to the first synchronous belt.

[0009] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, a guide groove is provided on the first side plate, and a guide rod extends from the sliding frame toward the guide groove, abutting against the inner wall of the guide groove and being able to slide relative to the guide groove.

[0010] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, a limiting groove is formed on the first side plate, a limiting bracket extending through the limiting groove is provided on the sliding frame toward the limiting groove, a limiting seat is installed on the side of the first side plate away from the sliding frame, and the side of the limiting bracket that passes through the limiting groove is bent toward the limiting seat to form a limiting hook.

[0011] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the second mounting member is threadedly engaged with the first mounting member; The output end of the second drive component is connected to a set of second drive wheels. A second driven wheel is rotatably connected to the mounting bracket. A second synchronous belt is wound between the second drive wheel and the second driven wheel. A synchronous key extends from the inner side of the second driven wheel. A keyway that mates with the synchronous key is opened on the second mounting component. The axial length of the keyway is greater than the length of the synchronous key.

[0012] In one specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the diameter of the second driven wheel is larger than the diameter of the second driving wheel.

[0013] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the second mounting member is internally through, and the probe is slidably fitted inside the second mounting member. The second mounting member is connected to the probe through an elastic member.

[0014] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the inner wall of the second mounting member is recessed to form a stepped mounting surface, and the two ends of the elastic member are respectively connected to the mounting surface and the probe.

[0015] As a specific embodiment of the optical lens thickness precision measurement device disclosed in this invention, the second mounting member has a display slot, and the probe extends with a display protrusion that penetrates the display slot.

[0016] In summary, the present invention has at least one of the following beneficial technical effects: 0. The measuring device disclosed in this invention achieves rapid and stable coarse positioning of the measuring probe in the vertical direction through the cooperation of the sliding frame, guide rail and synchronous belt drive. The sliding frame ensures the vertical accuracy of the motion trajectory through the sliding pair formed by the slider and the guide rail. The synchronous belt drive provides a relatively stable and accurate drive. The guide rod and guide groove structure further enhances the anti-torsion and anti-shaking ability of the sliding frame, ensuring that the probe is not prone to swaying during the movement, laying a stable positional foundation for subsequent fine measurement. 0. The second adjustment mechanism of the measuring device disclosed in this invention combines a high reduction ratio transmission with an elastic buffer probe. The second driving member drives the second driven wheel to rotate through a synchronous belt, and then drives the second mounting member to rotate through a keyway connection. The threaded pair converts it into axial feed, and at the same time, a preload spring provides controllable contact force to ensure that the probe and the lens surface are in flexible contact, effectively preventing the lens from being scratched or damaged by pressure. 0. The elastic buffer and displacement visualization compensation mechanism of the probe of the measuring device disclosed in this invention solves the measurement error problem that may be introduced by contact deformation. The probe tail is equipped with a spring to give it axial floating stroke, which can retract and buffer when in contact with the lens. At the same time, through the cooperation of the display protrusion fixed on the probe and the scale groove on the side wall of the second mounting part, the probe retraction amount can be detected intuitively or automatically to obtain the true thickness data through compensation, thereby ensuring the safety of the lens while ensuring the accuracy of the measurement results. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of an optical lens thickness precision measurement device disclosed in this invention; Figure 2 This is a schematic diagram of the first adjustment mechanism, the second adjustment mechanism, and the probe of a precision optical lens thickness measurement device disclosed in this invention. Figure 3 This is a schematic diagram of the structure of the second adjustment mechanism of an optical lens thickness precision measurement device disclosed in this invention; Figure 4 This is a schematic diagram of the structure of the first adjustment mechanism of an optical lens thickness precision measurement device disclosed in this invention; Figure 5 This is a schematic diagram of the internal structure of the probe of an optical lens thickness precision measurement device disclosed in this invention.

[0018] Figure label: 1. Frame; 2. Placement platform; 3. First adjustment mechanism; 31. Mounting bracket; 311. Upper mounting plate; 312. Lower mounting plate; 313. First side plate; 3131. Guide groove; 3132. Limiting groove; 3133. Limiting seat; 314. Second side plate; 3141. Guide rail; 315. Sliding frame; 3151. Guide rod; 3152. Limiting bracket; 3153. Limiting hook; 32. First driving component; 33. First mounting component; 34. First driving wheel; 35. First driven wheel; 36. First synchronous belt; 4. Second adjustment mechanism; 41. Second mounting component; 411. Keyway; 412. Display groove; 413. Mounting surface; 42. Second driving component; 43. Second driving wheel; 44. Second driven wheel; 441. Synchronization key; 45. Second synchronous belt; 5. Probe; 51. Elastic component; 52. Display protrusion. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings.

[0020] Please see Figure 1-5 This invention discloses a precision optical lens thickness measurement device. The main support structure of the measurement device is a frame 1. The frame 1 needs to have sufficient rigidity and stability to isolate external vibrations from interfering with the measurement process.

[0021] The frame 1 is equipped with at least one set of placement stages 2 for holding the optical lenses to be inspected. To accommodate batch or diverse inspection needs, multiple independent measurement units can be set up in parallel. Each measurement unit includes a placement stage 2 and a complete set of adjustment and measurement components. The design of the placement stage 2 must consider the stable placement and quick replacement of the lenses. Its surface can be covered with a flexible, scratch-resistant material, and appropriate adapter clamps or vacuum adsorption mechanisms can be designed according to the curvature of the lenses to ensure that the lenses do not shift or twist during the measurement process.

[0022] Above each placement platform 2, a first adjustment mechanism 3 is provided. The first adjustment mechanism 3 is responsible for the rapid vertical positioning of the probe 5. The first adjustment mechanism 3 includes a mounting bracket 31 mounted on the frame 1. The mounting bracket 31 specifically includes an upper mounting plate 311 at the top and a lower mounting plate 312 at the bottom, which are connected by a first side plate 313 and a second side plate 314. The first side plate 313 and the second side plate 314 are parallel to each other and together define a vertical sliding space. A sliding frame 315 moves linearly within this space. To ensure the stability of the sliding frame 315, a guide rail 3141 is installed on the inner side of the second side plate 314 facing the sliding space. A matching slider is provided on the sliding frame 315, and the two form a sliding pair to ensure that the movement trajectory of the sliding frame 315 is vertical and without sway.

[0023] The power to drive the sliding frame 315 comes from the first driving component 32, which is preferably a stepper motor or a servo motor. The first driving component 32 is fixedly mounted on the outer side of the first side plate 313. The output shaft of the first driving component 32 is connected to a first driving wheel 34, and a first driven wheel 35 is rotatably connected to the mounting bracket 31 via a bearing. A first synchronous belt 36 is tensioned and wound between the first driving wheel 34 and the first driven wheel 35. A connecting block extends from the sliding frame 315 toward the first synchronous belt 36 and is fixedly connected to the first synchronous belt 36. The connecting block and the first synchronous belt 36 can be fixed by adhesive or by clamping two plates together with bolts. When the first driving component 32 is activated, the driving wheel rotates, and through the synchronous belt drive, the sliding frame 315 can be precisely pulled up and down along the guide rail 3141.

[0024] To further enhance the stability and torque resistance of the sliding frame 315, a vertical guide groove 3131 is formed on the first side plate 313. A corresponding guide rod 3151 extends from the sliding frame 315, extending into the guide groove 3131, with its sidewall in sliding contact with the inner wall of the guide groove 3131. This design constitutes an additional guiding constraint, effectively preventing minor torsion or swaying of the sliding frame 315 due to forces during movement.

[0025] To ensure the safety of the movement of the first adjusting mechanism 3 and prevent damage to the mechanical structure due to accidental overtravel, a limiting groove 3132 is also provided next to the guide groove 3131 on the first side plate 313. A limiting bracket 3152 is fixed on the sliding frame 315, and the limiting bracket 3152 extends through the limiting groove 3132 to the outside of the first side plate 313. The limiting bracket 3152 is bent at the extended end to form a hook-shaped limiting hook 3153. A limiting seat 3133 is installed at the corresponding position on the outside of the first side plate 313. When the sliding frame 315 moves downward to the limit position, the limiting hook 3153 will contact the limiting seat 3133, thereby preventing the sliding frame 315 from continuing to move and achieving the purpose of physical limiting. Considering the impact during contact, the limiting seat 3133 can be made of flexible buffer materials such as polyurethane or engineering rubber to absorb impact energy and protect the transmission components.

[0026] The second drive component 42 is also preferably a stepper motor or a servo motor, and is fixedly mounted on the mounting bracket 31 of the first adjustment mechanism 3. The output shaft of the second drive component 42 is connected to a second drive wheel 43, and a second driven wheel 44 is rotatably supported on the mounting bracket 31 by bearings. The second drive wheel 43 and the second driven wheel 44 are connected by a second synchronous belt 45.

[0027] To transmit the rotational motion of the second driven wheel 44 to the second mounting member 41, a synchronization key 441 extends axially from the inner center of the second driven wheel 44. A keyway 411 matching the cross-sectional shape of the synchronization key 441 is formed on the side of the second mounting member 41. The synchronization key 441 is inserted into the keyway 411 to form an axially sliding spline connection. That is, the second driven wheel 44 can drive the second mounting member 41 to rotate synchronously, while allowing the second mounting member 41 to move freely axially relative to the driven wheel. In particular, the axial length of the keyway 411 is designed to be greater than the length of the synchronization key 441, which reserves space for subsequent axial extension and retraction of the second mounting member 41. To obtain a larger reduction ratio and finer displacement control, the diameter of the second driven wheel 44 is usually designed to be larger than the diameter of the second drive wheel 43. Combined with the reduction effect of the threaded pair, this makes the final feed of the probe 5 more precise and reliable.

[0028] The second mounting component 41 has a hollow, through-type internal structure, into which the main body of the probe 5 is axially slidable. A stepped, inwardly protruding surface 413 is machined into the inner wall of the second mounting component 41. An elastic element 51, typically a pre-calibrated miniature spring, is placed between the probe 5 and this mounting surface 413. One end of the spring rests against the mounting surface 413, and the other end against the tail of the probe 5. In its natural state, the pre-pressure of the spring causes the probe 5 to extend outward a certain distance. This design allows the probe 5 to have a certain elastic floating stroke relative to the second mounting component 41. When the probe 5 contacts the lens surface and pressure is applied, the probe 5 can retract inward relative to the second mounting component 41. The elastic element 51 transforms the contact between the probe 5 and the lens surface from a rigid contact to a flexible contact, with the contact force limited by the elastic force of the spring, effectively reducing the risk of scratching or crushing the lens due to overpressure.

[0029] To facilitate observation and compensation of the retraction amount of probe 5 due to contact with the lens, a longitudinal display groove 412 is provided on the side wall of the second mounting component 41. An indicator protrusion 52 is fixedly connected to probe 5, extending outward through the display groove 412. A scale can be printed or etched next to the display groove 412. When probe 5 contacts the lens and retracts, the indicator protrusion 52 moves accordingly, allowing the operator or vision system to directly read the retraction displacement. Furthermore, for neat and protected internal wiring, a cable guide is specially provided inside the second mounting component 41 to guide and protect the signal cable connecting probe 5, reducing the impact of cable tangling on measurement accuracy.

[0030] The working process of this precise optical lens thickness measurement device is as follows: First, the operator carefully places and secures the optical lens to be measured on the placement stage 2. After starting the device, the first adjustment mechanism 3 operates first. The first drive unit 32 receives a control signal and begins to rotate, driving the sliding frame 315, along with the entire second adjustment mechanism 4 and the probe 5, rapidly towards the lens for coarse positioning via the first synchronous belt 36. During this stage, the movement speed is relatively fast and the displacement is large, aiming to quickly bring the probe 5 to a working position close to the lens surface. When the sliding frame 315 moves to near a preset safe height, or when its limit hook contacts the descending limit seat 3133, the first drive unit 32 stops, completing the coarse positioning. At this point, only a small, safe gap remains between the tip of the probe 5 and the lens surface.

[0031] Subsequently, the second adjustment mechanism 4 begins operation, and the second drive component 42 starts rotating at a low speed, driving the second driven wheel 44 to rotate via the second synchronous belt 45. The second driven wheel 44 drives the second mounting component 41 to rotate via the synchronous key 441 and keyway 411. Due to the threaded engagement between the second mounting component 41 and the first mounting component 33, the rotation of the second mounting component 41 simultaneously drives its own precise downward feed along the thread axis. The probe 5 slowly approaches the lens surface. When the probe tip of the probe 5 just touches the lens surface, the probe 5 has not yet retracted due to the small contact force, and the device continues to feed slowly. Once the contact force reaches a preset small threshold, the probe 5 overcomes the preload of the internal spring and begins to retract inward relative to the second mounting component 41. At this time, the sensitive sensing element inside the probe 5, which can be a microswitch, piezoelectric sensor, or capacitive displacement sensor, will immediately detect this change in state and generate an electrical signal. This electrical signal is sent to the control system, which immediately commands the second drive component 42 to stop rotating. Thus, the contact state between the probe 5 and the lens is precisely locked.

[0032] Next, the device calculates the lens thickness using two complementary methods. The first is an electronic counting method: the control system precisely records the number of steps or angles rotated by the second drive member 42 from the start of the second adjustment mechanism 4 to the receipt of the stop signal. Since there is a determinable transmission ratio between the second drive member 42 and the final feed amount of the probe 5, the precise displacement of the second mounting member 41 itself from the start of fine feeding to the point where the probe 5 contacts the lens surface can be calculated, denoted as S1. However, this is only the displacement of the second mounting member 41. Due to the presence of a buffer spring, the probe 5 also has a retraction amount Δd after contact. This retraction amount Δd is obtained through mechanical reading: the operator or automated vision system reads the distance the display bump 52 moves on the scale of the display slot 412, which is Δd. Therefore, the total displacement of the probe 5 position corresponding to the actual contact point on the lens surface should be S1 - Δd. Combining this with the initial zero-point calibration position of the measuring device, the absolute thickness of the lens can be calculated. To improve efficiency and accuracy, the scale next to the display slot 412 can be equipped with a high-precision photoelectric encoder or grating ruler for automatic reading and automatic feedback of the Δd value to the control system, which will then calculate the final thickness result.

[0033] Throughout the measurement process, the first drive unit 32 is responsible for performing rapid, wide-range displacement, allowing the probe 5 to quickly enter the working area, greatly improving measurement efficiency. The second drive unit 42 is responsible for performing ultra-low-speed, extremely small-range precision displacement. Its high reduction ratio transmission design allows the probe 5 to "lightly touch" the mirror surface at an extremely slow speed. Combined with the elastic floating structure of the probe 5, this provides double protection for the lens. The retractable buffer design of the probe 5 not only protects the lens but also protects the probe 5 itself from impact damage. The cooperation between the display bump 52 and the scale cleverly solves the measurement error problem that may be introduced by the elastic retraction of the probe 5. Compensation is made by directly observing or automatically detecting the retraction amount, ensuring the accuracy and reliability of the thickness measurement results.

[0034] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A device for precisely measuring the thickness of an optical lens, characterized in that, include: The frame (1) is provided with: At least one set of placement stages (2) is used to place the lens to be inspected; The number of first adjustment mechanisms (3) is the same as that of the placement platform (2). Each set of first adjustment mechanisms (3) is arranged one-to-one above the placement platform (2). The first adjustment mechanism (3) includes a mounting frame (31) installed on the frame (1). The mounting frame (31) is slidably connected to a sliding frame (315). A first driving member (32) is installed on the mounting frame (31). The first driving member (32) drives the sliding frame (315) to slide vertically along the mounting frame (31). The sliding frame (315) is fixedly connected to the first mounting member (33). The number of second adjustment mechanisms (4) is the same as that of the first adjustment mechanism (3). Each group of second adjustment mechanisms (4) is installed on the mounting bracket (31) of the first adjustment mechanism (3). The second adjustment mechanism (4) includes a second mounting member (41) that can slide relative to the first mounting member (33) and a second driving member (42) that drives the second mounting member (41). The probe (5) is installed on the second mounting component (41).

2. The optical lens thickness precision measuring device according to claim 1, characterized in that: The mounting bracket (31) includes an upper mounting plate (311) and a lower mounting plate (312) located at both ends. A first side plate (313) and a second side plate (314) are connected between the upper mounting plate (311) and the lower mounting plate (312). A sliding space for a sliding frame (315) is formed between the first side plate (313) and the second side plate (314). The first driving member (32) is mounted on the first side plate (313). A guide rail (3141) is provided on the side of the second side plate (314) facing the first side plate (313). The sliding frame (315) slides in cooperation with the guide rail (3141).

3. The optical lens thickness precision measuring device according to claim 2, characterized in that: The output end of the first drive member (32) is connected to a first drive wheel (34), and a first driven wheel (35) is rotatably connected to the mounting bracket (31). A first synchronous belt (36) is wound between the first drive wheel (34) and the first driven wheel (35), and the sliding bracket (315) is fixedly connected to the first synchronous belt (36).

4. The optical lens thickness precision measuring device according to claim 2, characterized in that: The first side plate (313) has a guide groove (3131), and the sliding frame (315) extends toward the guide groove (3131) with a guide rod (3151) that abuts against the inner wall of the guide groove (3131) and can slide relative to the guide groove (3131).

5. The optical lens thickness precision measuring device according to claim 4, characterized in that: The first side plate (313) has a limiting groove (3132), and the sliding frame (315) has a limiting bracket (3152) extending through the limiting groove (3132) towards the position of the limiting groove (3132). A limiting seat (3133) is installed on the side of the first side plate (313) away from the sliding frame (315). The limiting bracket (3152) is bent in the direction of the limiting seat (3133) towards the limiting groove (3132) to form a limiting hook (3153).

6. The optical lens thickness precision measuring device according to claim 5, characterized in that: The second mounting part (41) is threadedly engaged with the first mounting part (33); The output end of the second drive member (42) is connected to a set of second drive wheels (43). A second driven wheel (44) is rotatably connected to the mounting bracket (31). A second synchronous belt (45) is wound between the second drive wheel (43) and the second driven wheel (44). A synchronous key (441) extends from the inner side of the second driven wheel (44). A keyway (411) that mates with the synchronous key (441) is opened on the second mounting member (41). The axial length of the keyway (411) is greater than the length of the synchronous key (441).

7. The optical lens thickness precision measuring device according to claim 6, characterized in that: The diameter of the second driven wheel (44) is larger than the diameter of the second driving wheel (43).

8. The optical lens thickness precision measuring device according to claim 1, characterized in that: The second mounting member (41) is internally through, and the probe (5) is slidably fitted inside the second mounting member (41). The second mounting member (41) is connected to the probe (5) through an elastic member (51).

9. The optical lens thickness precision measuring device according to claim 8, characterized in that: The inner wall of the second mounting member (41) is recessed to form a stepped mounting surface (413), and the two ends of the elastic member (51) are respectively connected to the mounting surface (413) and the probe (5).

10. The optical lens thickness precision measuring device according to claim 9, characterized in that: The second mounting component (41) has a display slot (412), and the probe (5) extends with a display protrusion (52) that penetrates the display slot (412).

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