Control device based on Hall effect

Abstract

The invention discloses a control device based on a Hall effect, and belongs to the field of beauty instruments. The device mainly comprises an age disc assembly, the age disc assembly comprises a stepping motor, a gear box shell is installed on the stepping motor, and a gear set is arranged in the gear box shell; a fixing support is installed on the gearbox shell, a PCBA board is installed on the fixing support, a plurality of sets of LED lamps are installed on the PCBA board and distributed in the radial direction of the PCBA board, and an age plate body is arranged on the gear set. A Hall sensing switch is installed on the PCBA board, a magnet is installed on the age plate body, a plurality of groups of age scales are installed on the age plate body, a horse race lampshade is installed on the PCBA board, and a plurality of groups of light marks are installed on the horse race lampshade. According to the control device based on the Hall effect, the rotation precision is improved through multi-stage gear transmission, accurate positioning of the age disc body is achieved in combination with real-time position feedback of the Hall induction switch and the magnet, and the interaction intuition is enhanced through visual linkage of the LED lamp and the age scales.

Description

Technical Field

[0001] The present invention relates to the technical field of beauty instruments, and in particular to a control device based on the Hall effect. Background Art

[0002] In today's society, people are increasingly concerned about their skin health and appearance, and the field of beauty testing has therefore experienced rapid development. As professional equipment capable of in-depth analysis of skin conditions, beauty testers are widely used in beauty salons, dermatology clinics, and home care settings. By testing and analyzing multiple indicators such as skin moisture content, oil secretion, elasticity, and wrinkles, beauty testers can provide users with a comprehensive skin condition assessment, providing a scientific basis for developing personalized skin care plans.

[0003] Skin age is a crucial indicator in beauty testing. It can intuitively reflect the overall health and aging of the skin, helping users to more clearly understand their skin condition and take targeted skin care measures. To accurately assess skin age, many beauty testers are equipped with corresponding detection algorithms and analysis systems.

[0004] The age display devices of traditional beauty testing equipment often use mechanical zero-position (such as scale line alignment) or manual button calibration, relying on the operator to visually align or trigger the key. This presents the following problems: Manual alignment errors are large: Visual calibration is affected by lighting and viewing angle, and the zero-position deviation can reach ±2 scale marks. Furthermore, manual calibration is required every time the device is turned on or the test mode is changed. A single calibration takes approximately 10-30 seconds, affecting test efficiency. Furthermore, angular deviations caused by gear wear after long-term use cannot be automatically eliminated and require professional disassembly and adjustment. Therefore, it is necessary to design a control device based on the Hall effect.

[0005] It should be noted that the above information disclosed in this Background section is only for understanding the background technology of the present application concept, and therefore, it may contain information that does not constitute prior art. Summary of the Invention

[0006] An embodiment of the present invention provides a control device based on the Hall effect to solve the problem that the age display device of traditional beauty detection equipment relies on manual calibration, resulting in large errors, long time consumption, gear wear causing deviations that are difficult to eliminate, and professional disassembly and adjustment are required.

[0007] The embodiment of the present invention adopts the following technical solution: a control device based on the Hall effect. It mainly comprises: an age dial assembly, which includes a stepper motor, a gearbox housing mounted on the stepper motor, and a gear set disposed within the gearbox housing; a fixing bracket mounted at the opening of the gearbox housing via fasteners, a PCBA mounted on the fixing bracket, and multiple sets of LED lights mounted on the PCBA, the multiple sets of LED lights being radially distributed at equal distances along the PCBA; an age dial body mounted on one end of the gear set; a Hall effect sensor mounted on the PCBA; a magnet mounted on the age dial body; multiple sets of age scales mounted on the age dial body; a marquee shade mounted on the PCBA, and multiple sets of light markings mounted on the marquee.

[0008] Furthermore, the output shaft of the stepper motor passes through the gear box housing, and the gear set includes a first gear mounted on the output shaft of the stepper motor, a second gear is mounted on a bearing at the bottom end of the inner wall of the gear box housing, the second gear is meshed with the first gear, the second gear has a rotating shaft, a third gear is mounted on the rotating shaft, a fourth gear is mounted on the bearing at the bottom end of the inner wall of the gear box housing, the fourth gear is meshed with the third gear, the fourth gear has a rotating shaft, the age disk body is mounted at one end of the rotating shaft, and the rotating shaft is at the center position of the gear box housing.

[0009] Furthermore, the fixed bracket has a disc, the rotating shaft passes through the fixed bracket and is located at the center of the disc on the fixed bracket. The PCBA board is a ring structure, one end of the rotating shaft passes through the fixed bracket and the PCBA board in sequence, and the age disc body is attached to the upper surface of the PCBA board. The diameter of the age disc body is smaller than the diameter of the PCBA board.

[0010] Furthermore, the plurality of groups of age scales are distributed along the radial direction of the age disk body, and each age scale corresponds to each LED light;

[0011] The Hall effect sensor switch corresponds to the magnet in an initial state, and an initial position of the Hall effect sensor switch corresponding to the magnet is a zero position.

[0012] Furthermore, the light marks are distributed along the radial direction of the marquee and correspond to the age scales. The light marks are composed of a group of triangular marks and multiple groups of circular marks.

[0013] Furthermore, a dustproof component is installed on the age disk body, and the dustproof component includes a fixing ring installed on the age disk body, two groups of fixing parts are symmetrically provided at both ends of the inner wall of the fixing ring, and two groups of dust shielding plates are rotatably installed between the two groups of the fixing parts. The dust shielding plates are made of transparent material and have an arc-shaped structure. There is a certain gap between the two groups of dust shielding plates when they are in a horizontal state.

[0014] Furthermore, a dust-proof brush is provided in the gap, and the dust-proof brush is installed between the two groups of the fixing parts.

[0015] Furthermore, two sets of positioning groups are installed on the inner wall of the fixing ring, and the two sets of positioning groups respectively support the two sets of dust shields in a horizontal state. The positioning group includes a mounting portion mounted on the inner wall of the fixing ring, and the mounting portion has two sets of protrusions. There is a certain distance between the two sets of protrusions. A convex ball is provided on the side of the two sets of protrusions close to each other, and a storage hole is opened on the side of the protrusion. A spring is connected between the convex ball and the storage hole.

[0016] The convex ball part is in the storage hole, and the remaining part of the convex ball protrudes from the storage hole. The bottom surface of the dust shield is equipped with a buckle block that snaps between two groups of the convex balls. A gripping part is installed on the side of the dust shield away from the buckle block. The positioning group is located at a position on the dust shield that does not block the age scale.

[0017] The at least one technical solution adopted in the embodiment of the present invention can achieve the following beneficial effects:

[0018] A control device based on the Hall effect improves rotation accuracy through multi-stage gear transmission and combines the real-time position feedback of the Hall effect sensor and magnet to achieve precise positioning of the age disk body. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] In the attached figure:

[0021] Figure 1 This is an overall schematic diagram of a control device based on the Hall effect in this application;

[0022] Figure 2 for Figure 1 Schematic diagram of the disassembly of the age disk assembly;

[0023] Figure 3 for Figure 2 Exploded view in ;

[0024] Figure 4 for Figure 3 A magnified view of point A in the figure;

[0025] Figure 5 for Figure 1 Schematic diagram of the dustproof component structure; Figure 6 Schematic diagram of the detector structure; Figure 7 for Figure 6 Schematic diagram of the bottom structure; Figure 8 for Figure 6 A partial cross-sectional view of a detector;

[0026] Reference numerals:

[0027] 1. Age dial assembly; 11. Stepper motor; 12. Gearbox housing; 13. Fixed bracket; 14. Gear set; 15. PCBA board; 151. First gear; 152. Second gear; 153. Third gear; 154. Fourth gear; 155. Rotating shaft; 16. LED light; 17. Hall effect switch; 18. Age dial body; 19. Age scale; 110. Marquee cover; 111. Light mark; 112. Magnet; 2. Dustproof assembly; 21. Fixed ring; 22. Fixed part; 23. Dust shield; 24. Positioning group; 241. Mounting part; 242. Protrusion; 243. Convex ball; 244. Buckle block; 25. Grip; 41. Detector; 42. Contact part; 43. Power button; 44. Heat dissipation mesh; 45. Scanning area. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0029] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] In this embodiment, the Hall effect control device is mainly installed inside the detector 41. The detector 41 is provided with a contact portion 42 that contacts the patient's facial skin, and a power button 43 is provided on the detector 41 at a side of the contact portion 42. The power button 43 is used to control the power on and off of the detector 41. The detector 41 is also provided with a heat dissipation mesh 44. The heat dissipation mesh 44 is used to dissipate heat from the internal devices of the detector 41, thereby preventing the internal electrical components and power supply from heating up and causing the outer shell of the detector 41 to heat up during use, thereby improving the comfort during use.

[0031] A scanning area 45 is provided on the side of the detector 41 away from the power button 43. The scanning area 45 is equipped with two lenses, namely a hyperspectral lens and an RGB lens.

[0032] Reference Figures 1 to 8 As shown, an embodiment of the present invention provides a control device based on the Hall effect, which mainly includes an age disc assembly 1 arranged inside a detector 41 and a dustproof assembly 2 installed on the age disc assembly 1;

[0033] Reference Figures 1 to 4 As shown, the age disk assembly 1 includes a stepper motor 11 for driving rotation, and a gear box housing 12 is fixedly installed on one side of the stepper motor 11 close to the output shaft, and a gear set 14 is provided in the gear box housing 12. The output shaft of the stepper motor 11 passes through the gear box housing 12, and the gear set 14 includes a first gear 151 fixedly installed on the output shaft of the stepper motor 11, and a second gear 152 is installed on a bearing at the bottom end of the inner wall of the gear box housing 12. The second gear 152 is meshed with the first gear 151, and the second gear 152 has a rotating shaft (not shown in the figure), and a third gear 153 is fixedly installed on the rotating shaft. At the same time, a fourth gear 154 is installed on a bearing at the bottom end of the inner wall of the gear box housing 12, and the fourth gear 154 is meshed with the third gear 153. The fourth gear 154 has a rotating shaft 155, and the rotating shaft 155 is located at the center of the gear box housing 12.

[0034] At the same time, a fixing bracket 13 is installed at the opening of the gearbox housing 12 through fasteners. The fixing bracket 13 has a circular disc, and the rotating shaft 155 passes through the fixing bracket 13 and is located at the center of the circular disc on the fixing bracket 13. A PCBA board 15 is fixedly installed on the fixing bracket 13. The PCBA board 15 has an annular structure, and a plurality of groups of LED lights 16 are fixedly installed on the side of the PCBA board 15 away from the fixing bracket 13. The plurality of LED lights 16 are radially distributed at equal distances along the PCBA board 15.

[0035] At the same time, one end of the rotating shaft 155 passes through the fixed bracket 13 and the PCBA board 15 in sequence, and an age disc body 18 is fixedly installed on one end of the rotating shaft 155. The age disc body 18 is attached to the upper surface of the PCBA board 15, and the diameter of the age disc body 18 is smaller than the diameter of the PCBA board 15.

[0036] After the stepper motor 11 is powered on, the output shaft begins to rotate. Since the first gear 151 is fixedly mounted on the output shaft of the stepper motor 11, the first gear 151 rotates accordingly. The first gear 151 is engaged with the second gear 152, and through gear transmission, drives the second gear 152 to rotate around its bearing mounting point. The third gear 153 is fixedly mounted on the rotating shaft of the second gear 152, so the third gear 153 rotates synchronously. The third gear 153 is in turn engaged with the fourth gear 154, thereby driving the fourth gear 154 to rotate. The rotating shaft 155 of the fourth gear 154 is located at the center of the gearbox housing 12, transmitting the power of the stepper motor 11 in sequence, and finally rotating the rotating shaft 155.

[0037] A rotating shaft 155 extends through the fixed bracket 13 and is located at the center of the fixed bracket 13. The age disc 18 is fixedly mounted on one end of the rotating shaft 155. As the rotating shaft 155 rotates, the age disc 18 also rotates around the center of the fixed bracket 13, realizing the rotation function of the age disc 18, which is used to indicate or display relevant age information.

[0038] A Hall effect sensor 17 is fixedly mounted on a surface of the PCBA board 15 close to the fixing bracket 13. A magnet 112 is fixedly mounted on a surface of the age dial body 18 close to the PCBA board 15. Furthermore, a plurality of age scales 19 are fixedly mounted on a surface of the age dial body 18 away from the PCBA board 15. The plurality of age scales 19 are distributed radially along the age dial body 18, and each age scale 19 corresponds to each LED light 16. The age scale 19 ranges from 18 to 56 years old.

[0039] It should be noted that the Hall sensor switch 17 corresponds to the magnet 112 in the initial state, and the initial position of the Hall sensor switch 17 corresponding to the magnet 112 is the zero position, that is, the position of 18;

[0040] The stepper motor 11 serves as a power source, and its output shaft begins to rotate after power is turned on. Since the first gear 151 is fixedly connected to the output shaft of the stepper motor 11, the first gear 151 rotates accordingly. The first gear 151 meshes with the second gear 152, driving the second gear 152 to rotate around its bearing mounting point at the bottom end of the inner wall of the gearbox housing 12. And because the third gear 153 is mounted on the rotating shaft of the second gear 152, the third gear 153 rotates synchronously. The third gear 153 meshes with the fourth gear 154, driving the fourth gear 154 to rotate. The rotating shaft 155 of the fourth gear 154 is located at the center of the gearbox housing 12, and the rotating shaft 155 passes through the fixed bracket 13 and is fixedly connected to the age disk body 18. Therefore, the power of the stepper motor 11 is finally transmitted to the age disk body 18, causing it to rotate around the center of the disk on the fixed bracket 13.

[0041] In the initial state, the Hall sensor switch 17 corresponds to the magnet 112, and this position is set to zero, which is the position of 18 years old in the age scale 19. This provides a reference position for the subsequent rotation of the age disk body 18.

[0042] When the stepper motor 11 drives the age disc 18 to rotate, the magnet 112 mounted on it rotates accordingly. The Hall effect sensor 17 senses changes in the surrounding magnetic field. When the magnet 112 rotates past the Hall effect sensor 17, it detects the magnetic field change and generates an electrical signal. This signal is transmitted to the control system (typically integrated on the PCBA 15). The control system records information such as the number of signal occurrences, frequency, and time interval, and combines it with parameters such as the gear ratio to accurately calculate the rotation angle and number of revolutions of the age disc 18, thereby determining the current position of the age disc 18 in real time.

[0043] On the side of the age dial body 18 facing away from the PCBA board 15, multiple age scales 19 ranging from 18 to 56 are arranged radially along the age dial body 18. Simultaneously, multiple groups of LED lights 16 are distributed equidistantly along the PCBA board 15, with each age scale 19 corresponding to a corresponding LED light 16.

[0044] When the beauty detector completes the skin test, it will get a skin age test result. Based on this result, the control system controls the stepper motor 11 to rotate the corresponding angle, driving the age dial body 18 to rotate to the age scale 19 position corresponding to the test result.

[0045] A marquee cover 110 is fixedly mounted on the PCBA board 15. The marquee cover 110 is annular in structure and has multiple sets of light marks 111 fixedly mounted on the marquee cover 110. The light marks 111 are distributed radially along the marquee cover 110 and correspond to the age scale 19. The light marks 111 are composed of a set of triangular marks and multiple sets of circular marks. The triangular marks correspond to the age dial body 18 from the initial 18-year-old position. The marquee cover 110 is used to protect the LED lights 16.

[0046] Working Principle: After the beauty detector completes skin age detection, the control system triggers the stepper motor 11 to energize it. Its output shaft transmits power to the rotating shaft 155 through a multi-stage gear transmission from the first gear 151 to the fourth gear 154, driving the age dial body 18 to rotate around the center of the fixed bracket 13. Initially, the Hall effect sensor 17 and the magnet 112 on the age dial body 18 correspond to the zero position. As the age dial rotates, the magnet 112 moves with it. The Hall effect sensor 17 detects the change in the magnetic field and generates an electrical signal. This signal is fed back to the control system integrated in the PCBA board 15. Combined with the gear ratio, the signal accurately calculates the rotation angle and determines the real-time position of the age dial body 18.

[0047] The radial age scale 19 on the age dial body 18, ranging from 18 to 56, corresponds one-to-one with the radially distributed LED lights 16 on the PCBA board 15. When the test result is a certain age, the control system drives the stepper motor 11 to rotate a specific angle, aligning the corresponding age scale 19 with the light mark 111 on the marquee cover 110 (for example, the triangle mark indicates the initial position, and the circular mark corresponds to different age groups). At this time, the LED light 16 corresponding to the target age lights up. At the same time, the annular marquee cover 110 protects the LED lights 16, ensuring long-term stable operation of the device. The entire process achieves accurate determination of skin age through Hall effect positioning, gear transmission precision control, and visual light feedback.

[0048] In a specific embodiment, in order to solve the problem that external dust easily enters the age scale 19 on the age disk body 18 inside the detector 41 through the heat dissipation mesh 44 and falls on the age scale 19, refer to Figure 1 and Figure 5 As shown, a dustproof assembly 2 is installed on the age disk body 18. The dustproof assembly 2 includes a fixing ring 21 fixedly installed on the age disk body 18, and two sets of fixing parts 22 are symmetrically provided at both ends of the inner wall of the fixing ring 21. Two sets of dust shielding plates 23 are rotatably installed between the two sets of fixing parts 22. The dust shielding plates 23 are made of transparent material and have an arc-shaped structure. There is a certain gap between the two sets of dust shielding plates 23 in a horizontal state.

[0049] In the present application, a dust-proof brush is provided in the gap, the dust-proof brush is fixedly installed between the two sets of fixing parts 22, and the dust-proof brush is used to cover the gap;

[0050] Two sets of positioning groups 24 are fixedly mounted on the inner wall of the fixing ring 21. The two sets of positioning groups 24 respectively support the two sets of dust shielding plates 23 in a horizontal state. The positioning groups 24 include a mounting portion 241 fixedly mounted on the inner wall of the fixing ring 21. The mounting portion 241 has two sets of protrusions 242. There is a certain distance between the two sets of protrusions 242. A convex ball 243 is provided on the side of the two sets of protrusions 242 that are close to each other. At the same time, a storage hole (not shown in the figure) is opened on the side of the protrusion 242. A spring (not shown in the figure) is connected between the convex ball 243 and the storage hole.

[0051] Part of the convex ball 243 is located in the storage hole, and the remaining part of the convex ball 243 protrudes from the storage hole. At the same time, a buckle block 244 is fixedly installed on the bottom surface of the dust shield 23 and is engaged between the two groups of convex balls 243. A grip portion 25 is fixedly installed on the side of the dust shield 23 away from the buckle block 244. The grip portion 25 is suitable for driving the dust shield 23 to rotate.

[0052] It should be noted that the positioning group 24 is located at a position on the dust shield 23 that does not block the age scale 19, and the two sets of dust shields 23 are used to protect the age scale 19 and the components on the age disk body 18 from dust in the default horizontal state;

[0053] Working Principle: In their default state, the two sets of transparent curved dust shields 23 are horizontally aligned, with a dust-proof brush located between them tightly blocking the gap. This creates a dust barrier covering the surface of the age dial body 18, preventing dust from adhering to the age scale 19 and the dial components. At this point, the buckle 244 on the bottom of the dust shield 23 fits between the two sets of protruding balls 243 of the positioning assembly 24 on the inner wall of the retaining ring 21. The spring-loaded balls 243 engage the buckle 244, maintaining a stable horizontal, sealed state for the dust shield 23. The transparent material ensures that the user can clearly observe the scale through the dust shield 23.

[0054] When inspecting components on the age disc body 18, the user grasps the grip 25 and applies a rotational force, causing the dust shield 23 to rotate about the fixing portion 22. During this rotation, the buckle 244 squeezes the protruding ball 243, forcing it back into the storage hole against the spring force, thereby releasing the dust shield 23. When the dust shield 23 rotates to the unobstructed position (e.g., vertical or at an angle) predetermined by the positioning assembly 24, the buckle 244 aligns with the newly positioned protruding ball 243. The spring pushes the protruding ball 243 back into the buckle 244, locking the dust shield 23 in the open position. This fully exposes the age scale 19 and the disc body, facilitating user operation. After the operation is complete, the grip 25 is rotated in the opposite direction, returning the dust shield 23 to its horizontal position. The buckle 244 reengages and locks the horizontal protruding ball 243, and the dust brush simultaneously resumes its shielding of the gap, ensuring that the age disc body 18 remains protected from dust. The structural design of the arc-shaped transparent dust shield 23 not only fits the curvature of the disk body to enhance the dustproof sealing, but also realizes the stable switching of the opening and closing states through the spring-convex ball 243 of the positioning group 24, taking into account both dustproof performance and user convenience.

[0055] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A control device based on the Hall effect, provided in a skin detector, characterized in that: include: An age disc assembly (1) includes a stepping motor (11), a gear box housing (12) is mounted on the stepping motor (11), and a gear set (14) is arranged in the gear box housing (12); A fixing bracket (13) is installed at the opening of the gear box housing (12) through a fastener, a PCBA board (15) is installed on the fixing bracket (13), a plurality of groups of LED lights (16) are installed on the PCBA board (15), and the plurality of groups of LED lights (16) are radially distributed at equal distances along the PCBA board (15), and an age disk body (18) is installed at one end of the gear set (14); A Hall sensor switch (17) is installed on the PCBA board (15), a magnet (112) is installed on the age disc body (18), multiple groups of age scales (19) are installed on the age disc body (18), a marquee cover (110) is installed on the PCBA board (15), and multiple groups of light marks (111) are installed on the marquee cover (110).

2. The Hall effect-based control device according to claim 1, characterized in that: The output shaft of the stepper motor (11) passes through the gear box housing (12); the gear set (14) includes a first gear (151) mounted on the output shaft of the stepper motor (11); a second gear (152) is mounted on a bearing at the bottom end of the inner wall of the gear box housing (12); the second gear (152) is meshed with the first gear (151); the second gear (152) has a rotating shaft; a third gear (153) is mounted on the rotating shaft; a fourth gear (154) is mounted on a bearing at the bottom end of the inner wall of the gear box housing (12); the fourth gear (154) is meshed with the third gear (153); the fourth gear (154) has a rotating shaft (155); the age disk body (18) is mounted on one end of the rotating shaft (155); the rotating shaft (155) is located at the center of the gear box housing (12).

3. The Hall effect-based control device according to claim 2, characterized in that: The fixed bracket (13) has a circular disc, the rotating shaft (155) passes through the fixed bracket (13) and is located at the center of the circular disc on the fixed bracket (13), the PCBA board (15) is an annular structure, one end of the rotating shaft (155) passes through the fixed bracket (13) and the PCBA board (15) in sequence, the age disc body (18) is attached to the upper surface of the PCBA board (15), and the diameter of the age disc body (18) is smaller than the diameter of the PCBA board (15).

4. The Hall effect-based control device according to claim 3, characterized in that: A plurality of groups of age scales (19) are distributed along the radial direction of the age disk body (18), and each age scale (19) corresponds to each LED light (16); The Hall sensor switch (17) corresponds to the magnet (112) in an initial state, and the initial position of the Hall sensor switch (17) corresponding to the magnet (112) is zero.

5. The Hall effect-based control device according to claim 4, characterized in that: The light marks (111) are distributed along the radial direction of the marquee (110) and correspond to the age scale (19). The light marks (111) are composed of a group of triangular marks and a plurality of groups of circular marks.

6. The Hall effect-based control device according to any one of claims 1 to 5, characterized in that: The invention also includes a dustproof component (2), wherein the dustproof component (2) includes a fixing ring (21) mounted on the age plate body (18), two groups of fixing parts (22) are symmetrically arranged at both ends of the inner wall of the fixing ring (21), and two groups of dust shielding plates (23) are rotatably mounted between the two groups of the fixing parts (22), the dust shielding plates (23) are made of a transparent material, and the dust shielding plates (23) are of an arc-shaped structure. There is a certain gap between the two groups of the dust shielding plates (23) when they are in a horizontal state.

7. The Hall effect-based control device according to claim 6, characterized in that: A dustproof brush is provided in the gap, and the dustproof brush is installed between the two groups of fixing parts (22).

8. The Hall effect-based control device according to claim 7, characterized in that: Two groups of positioning groups (24) are installed on the inner wall of the fixing ring (21), and the two groups of positioning groups (24) respectively support the two groups of dust shielding plates (23) in a horizontal state. The positioning group (24) includes a mounting portion (241) mounted on the inner wall of the fixing ring (21), and the mounting portion (241) has two groups of protrusions (242). There is a certain distance between the two groups of protrusions (242). A convex ball (243) is provided on the side close to each other of the two groups of protrusions (242). A storage hole is opened on the side of the protrusion (242), and a spring is connected between the convex ball (243) and the storage hole. Part of the convex ball (243) is located in the storage hole, and the remaining part of the convex ball (243) protrudes from the storage hole. The bottom surface of the dust shielding plate (23) is equipped with a buckle block (244) that is buckled between two groups of the convex balls (243). A gripping portion (25) is installed on the side of the dust shielding plate (23) away from the buckle block (244). The positioning group (24) is located at a position on the dust shielding plate (23) that does not block the age scale (19).

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