A multi-focal fresnel lens for detecting a pet

Abstract

The utility model relates to the technical field of fresnel lens, disclose a kind of multi-focal fresnel lens for detecting pet, including shell, the shell inside is provided with focusing component, shell outer wall is fixedly connected with connecting shell, the focusing component includes spiral chute, slide bar and straight chute, the shell inside is provided with swivel sleeve, the swivel sleeve inside is provided with inner shell, the inner shell inside is provided with focusing lens, the slide bar outer wall is slidably connected in straight chute and spiral chute inside, the inner shell one end is fixedly connected with connecting ring, the connecting ring inside is provided with connecting assembly. In the utility model, focusing component is driven by the rotation of swivel sleeve, so that slide bar moves along spiral chute and straight chute composite, drives focusing lens to accurately linearly displace in inner shell, different focal length mode can be switched quickly, without replacing lens or complex calibration, the structure improves the response efficiency of pet dynamic detection, especially suitable for the rapid identification of different distance pet.

Description

Technical Field

[0001] This utility model relates to the field of Fresnel lens technology, and in particular to a multifocal Fresnel lens for detecting pets. Background Technology

[0002] With the increasing demand for smart home security, pet dynamic monitoring technology has become an important branch of the surveillance lens field. Fresnel lenses are widely used in infrared pet detection devices due to their thinness and high light transmittance. However, traditional single-focal-length lenses are difficult to adapt to the distance changes of pets in complex indoor and outdoor environments. Multifocal Fresnel lenses can significantly improve the recognition accuracy of pet targets at different distances by dynamically adjusting the optical focus, becoming a key technology direction for solving the pain points of moving target monitoring.

[0003] The current mainstream solution adopts a manual threaded focusing structure, which has a precision thread machined on the inner wall of the lens barrel. The lens group moves axially by rotating the threaded ring on the outer wall. Its technical principle relies on the linear relationship between the thread lead and the lens displacement. Users need to rotate the focusing ring to drive the lens to move back and forth, and estimate the focal length position by using the distance scale ring on the surface of the lens barrel. This purely mechanical structure relies entirely on manual operation.

[0004] However, manual thread focusing requires repeated rotation and calibration to match the target distance. When pets move quickly indoors or outdoors, operators cannot capture key movements in time due to focusing delays. Frequent switching between near and far distances causes the human response speed to lag significantly behind changes in pet behavior, and a large number of dynamic moments are not effectively recorded. This response lag is particularly prominent in multi-room, large-area monitoring scenarios, which greatly limits the practicality of the detection system. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a multifocal Fresnel lens for detecting pets, aiming to improve the problem of slow manual focusing speed.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a multifocal Fresnel lens for detecting pets, comprising a housing, a focusing assembly disposed inside the housing, and a connecting shell fixedly connected to the outer wall of the housing;

[0007] The focusing assembly includes a spiral groove, a slide rod, and a straight groove. A rotating sleeve is provided inside the outer shell. The spiral groove is formed through the inside of the rotating sleeve. An inner shell is provided inside the rotating sleeve. The straight groove is formed through the inside of the inner shell. A focusing lens is provided inside the inner shell. One end of the slide rod is fixedly connected to the outer wall of the focusing lens. The outer wall of the slide rod is slidably connected to the inside of the straight groove. The outer wall of the slide rod is slidably connected to the inside of the spiral groove. A connecting ring is fixedly connected to one end of the inner shell. A connecting component is provided inside the connecting ring.

[0008] Furthermore, the connecting assembly includes a locking rod, the outer wall of which is slidably connected to the inner wall of the connecting ring. The connecting ring has an inner ring inside, and a connecting block is slidably connected to the inner wall of the inner ring. One end of the locking rod is fixedly connected to the outer wall of the connecting block, and the locking block is fixedly connected to the outer wall of the connecting ring.

[0009] Furthermore, a button is fixedly connected to the outer wall of the connecting block, and the outer wall of the button is slidably connected to the inner wall of the connecting ring.

[0010] Furthermore, a spring is provided inside the inner ring, and one end of the spring is fixedly connected to the outer wall of the connecting block.

[0011] Furthermore, a toothed ring is fixedly connected to the outer wall of the sleeve, and a motor is installed inside the connecting shell.

[0012] Furthermore, a gear is fixedly connected to the output end of the motor, and the gear ring meshes with the gear.

[0013] Furthermore, a fixed cover is fixedly connected to the outer wall of the outer shell, and a fixed lens is provided inside the outer shell, wherein the focusing lens has the same structure as the fixed lens.

[0014] Furthermore, a central Fresnel lens element is provided in the center of the front surface of the fixed lens, a non-textured area is provided on one side of the central Fresnel lens element, a first ring Fresnel lens element is provided around the side of the central Fresnel lens element away from the non-textured area, a second ring Fresnel lens element is provided around the outside of the first ring Fresnel lens element, and a third ring Fresnel lens element is provided around the outside of the second ring Fresnel lens element.

[0015] This utility model has the following beneficial effects:

[0016] 1. In this utility model, the focusing component is driven by the rotation of the rotating sleeve, which causes the slide rod to move along the spiral slide groove and the straight slide groove in combination, thereby driving the focusing lens to move precisely and linearly in the inner shell. During operation, only the rotation angle of the rotating sleeve needs to be controlled to quickly switch between different focal length modes without the need to replace the lens or perform complex calibration. This structure improves the response efficiency of pet dynamic detection, and is especially suitable for the rapid identification of pets at different distances. Moreover, the mechanical transmission is stable and reliable, reducing the complexity of multi-focal length adjustment.

[0017] 2. In this utility model, the connecting component adopts a spring-pre-tightened locking structure. When the button is pressed, the connecting block drives the locking rod to retract synchronously, realizing the rapid separation of the focusing lens from the external device. After the button is released, the spring automatically resets to lock the locking rod. This design simplifies the lens disassembly and assembly process, and maintenance or replacement can be completed with only one hand. It avoids the tool dependence and time-consuming problems of traditional threaded disassembly, and significantly improves the convenience of equipment maintenance. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of a multifocal Fresnel lens for detecting pets proposed in this utility model;

[0019] Figure 2 This is a schematic diagram of a multifocal Fresnel lens for detecting pets proposed in this utility model.

[0020] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0021] Figure 4 This is a schematic diagram of the connecting ring structure of a multifocal Fresnel lens for detecting pets proposed in this utility model;

[0022] Figure 5 for Figure 4 Enlarged diagram of point B in the middle.

[0023] Legend:

[0024] 1. Outer shell; 2. Connecting shell; 3. Rotary sleeve; 4. Spiral groove; 5. Focusing lens; 6. Slide rod; 7. Inner shell; 8. Straight groove; 9. Fixing cover; 10. Fixing lens; 11. Gear ring; 12. Gear; 13. Motor; 14. Connecting ring; 15. Locking block; 16. Button; 17. Connecting block; 18. Locking rod; 19. Spring; 20. Inner ring; 21. Central Fresnel lens element; 22. First ring Fresnel lens element; 23. Second ring Fresnel lens element; 24. Third ring Fresnel lens element; 25. Non-textured area. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Reference Figure 1 - Figure 5This utility model provides an embodiment of a multifocal Fresnel lens for detecting pets, comprising a housing 1 for support, a focusing assembly inside the housing 1 for focal length switching, a connecting shell 2 fixedly connected to the outer wall of the housing 1 for mounting a driving component and connecting to an external device, the focusing assembly comprising a spiral groove 4, a slide rod 6, and a straight groove 8 forming a motion conversion mechanism, a rotating sleeve 3 inside the housing 1, the spiral groove 4 penetrating inside the rotating sleeve 3, an inner shell 7 inside the rotating sleeve 3 for accommodating a focusing lens 5, the straight groove 8 penetrating inside the inner shell 7 limiting the slide rod 6 to linear movement, the focusing lens 5 inside the inner shell 7, and the movement of the focusing lens 5 to change the system focal length, one end of the slide rod 6 being fixedly connected to the outer wall of the focusing lens 5 to transmit the movement of the slide rod 6. For the lens, the outer wall of the slide rod 6 is slidably connected to the inside of the straight slide groove 8, and the outer wall of the slide rod 6 is slidably connected to the inside of the spiral slide groove 4. One end of the inner shell 7 is fixedly connected to a connecting ring 14. The connecting ring 14 is provided with a connecting component for connecting the entire focusing lens module to an external device and realizing quick assembly and disassembly of the lens and the device body. The connecting component includes a locking lever 18 that extends or retracts to lock or unlock. The outer wall of the locking lever 18 is slidably connected to the inner wall of the connecting ring 14. The locking lever 18 can move radially within the connecting ring 14. The connecting ring 14 is provided with an inner ring 20 to accommodate the connecting component parts. A connecting block 17 is slidably connected to the inner wall of the inner ring 20. One end of the locking lever 18 is fixedly connected to the outer wall of the connecting block 17. The outer wall of the connecting ring 14 is fixedly connected to a locking block 15 that is connected to the external device. The groove fits to assist in positioning and prevent rotation. A button 16 is fixedly connected to the outer wall of the connecting block 17. The outer wall of the button 16 is slidably connected to the inner wall of the connecting ring 14. A spring 19 is provided inside the inner ring 20 to provide elastic force for locking the lever 18 outward. One end of the spring 19 is fixedly connected to the outer wall of the connecting block 17. A toothed ring 11 is fixedly connected to the outer wall of the rotating sleeve 3. A motor 13 is provided inside the connecting shell 2 to provide driving force. A gear 12 is fixedly connected to the output end of the motor 13. The toothed ring 11 and the gear 12 are meshed. A fixing cover 9 is fixedly connected to the outer wall of the outer shell 1 to protect the internal optical components. A fixed lens 10 and a focusing lens 5 are provided inside the outer shell 1 to form an optical system. The focusing lens 5 has the same structure as the fixed lens 10 and its position is fixed. The front of the fixed lens 10 A central Fresnel lens element 21 is located in the center, with a non-textured area 25 on one side of the central Fresnel lens element 21. The installation height is approximately half a meter above the ground. Infrared light emitted by the pet is focused onto the pyroelectric sensor through the Fresnel lens element, minimizing human interference and thus achieving the purpose of sensing the pet. A first ring of Fresnel lens elements 22 surrounds the central Fresnel lens element 21 away from the non-textured area 25. A second ring of Fresnel lens elements 23 surrounds the first ring of Fresnel lens elements 22, and a third ring of Fresnel lens elements 24 surrounds the second ring of Fresnel lens elements 23. All lens elements are aspherical, maximizing the correction of spherical aberration and improving the optical power density of the focused spot.To make Fresnel lenses more sensitive than ordinary lenses, the Fresnel lens employs the aforementioned structural design. While meeting the requirements for detection distance, detection angle, and appearance, this multi-focal-length Fresnel lens is smaller, thinner, less expensive to manufacture, and more competitive in the market.

[0027] Working principle: When using this multifocal Fresnel lens for pet detection, the motor 13 is first started to drive the gear 12 to rotate. The gear 12, through meshing with the gear ring 11 on the outer wall of the sleeve 3, drives the sleeve 3 to rotate. The spiral groove 4 inside the sleeve 3 and the straight groove 8 on the inner shell 7 form a compound motion track, causing the slide rod 6 fixed to the outer wall of the focusing lens 5 to slide synchronously along the curved path of the spiral groove 4 and the straight path of the straight groove 8, thereby pushing the focusing lens 5 to linearly displace within the inner shell 7. After the infrared light enters through the fixed cover 9 on the outer wall of the outer shell 1, it is initially focused by the fixed lens 10 inside the outer shell 1, and then the focusing lens 5 dynamically adjusts the secondary focusing path. The target signal is transmitted to the processor through the connecting shell 2 to complete the pet trajectory analysis. During maintenance, press the button 16 on the connecting ring 14 to push the connecting block 17. The spring 19 inside the compressed inner ring 20, the connecting block 17 drives the locking rod 18 to retract radially and disengage from the external device's locking slot. Then, the lens is rotated so that the locking block 15 is aligned with the external device's connection notch and pulled out, achieving rapid separation. After releasing the button 16, the spring 19 automatically resets, causing the locking rod 18 to pop out and lock. The Fresnel lens used is a multi-focal length design, with each ring having a corresponding focal length. The upper half of the lens is a non-textured area 25, and the central Fresnel lens element 21, the first ring Fresnel lens element 22, the second ring Fresnel lens element 23, and the third ring Fresnel lens element 24 are all aspherical lenses. The installation height is about half a meter above the ground. The infrared light emitted by the pet is focused onto the pyroelectric sensor by the Fresnel lens element, and human interference can be minimized, thereby achieving the purpose of sensing the pet.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multifocal Fresnel lens for detecting pets, comprising a housing (1), characterized in that: The housing (1) is provided with a focusing assembly inside, and a connecting shell (2) is fixedly connected to the outer wall of the housing (1); The focusing assembly includes a spiral groove (4), a slide rod (6), and a straight groove (8). A rotating sleeve (3) is provided inside the outer shell (1). The spiral groove (4) is opened through the inside of the rotating sleeve (3). An inner shell (7) is provided inside the rotating sleeve (3). The straight groove (8) is opened through the inside of the inner shell (7). A focusing lens (5) is provided inside the inner shell (7). One end of the slide rod (6) is fixedly connected to the outer wall of the focusing lens (5). The outer wall of the slide rod (6) is slidably connected to the inside of the straight groove (8). The outer wall of the slide rod (6) is slidably connected to the inside of the spiral groove (4). A connecting ring (14) is fixedly connected to one end of the inner shell (7). A connecting component is provided inside the connecting ring (14).

2. A multifocal Fresnel lens for detecting pets according to claim 1, characterized in that: The connecting assembly includes a lever (18), the outer wall of which is slidably connected to the inner wall of a connecting ring (14). An inner ring (20) is provided inside the connecting ring (14), and a connecting block (17) is slidably connected to the inner wall of the inner ring (20). One end of the lever (18) is fixedly connected to the outer wall of the connecting block (17), and a lever (15) is fixedly connected to the outer wall of the connecting ring (14).

3. A multifocal Fresnel lens for detecting pets according to claim 2, characterized in that: A button (16) is fixedly connected to the outer wall of the connecting block (17), and the outer wall of the button (16) is slidably connected to the inner wall of the connecting ring (14).

4. A multifocal Fresnel lens for detecting pets according to claim 3, characterized in that: A spring (19) is provided inside the inner ring (20), and one end of the spring (19) is fixedly connected to the outer wall of the connecting block (17).

5. A multifocal Fresnel lens for detecting pets according to claim 1, characterized in that: A toothed ring (11) is fixedly connected to the outer wall of the sleeve (3), and a motor (13) is installed inside the connecting shell (2).

6. A multifocal Fresnel lens for detecting pets according to claim 5, characterized in that: The output end of the motor (13) is fixedly connected to a gear (12), and the gear ring (11) meshes with the gear (12).

7. A multifocal Fresnel lens for detecting pets according to claim 1, characterized in that: The outer wall of the outer shell (1) is fixedly connected to a fixed cover (9), and a fixed lens (10) is provided inside the outer shell (1). The focusing lens (5) has the same structure as the fixed lens (10).

8. A multifocal Fresnel lens for detecting pets according to claim 7, characterized in that: The fixed lens (10) has a central Fresnel lens element (21) in the center of its front surface. A non-textured area (25) is provided on one side of the central Fresnel lens element (21). A first ring Fresnel lens element (22) is provided around the side of the central Fresnel lens element (21) away from the non-textured area (25). A second ring Fresnel lens element (23) is provided around the outside of the first ring Fresnel lens element (22). A third ring Fresnel lens element (24) is provided around the outside of the second ring Fresnel lens element (23).

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