Lens zero positioning structure

Abstract

The utility model is suitable for the technical field of lenses, and provides a zero positioning structure of a lens, which is applied to a lens main body and a focusing assembly thereof, and comprises a positioning plate arranged on the lens main body, a Hall element plate arranged on the positioning plate and a driving assembly for driving the focusing assembly to rotate, and a magnetic bead arranged on the focusing assembly and matched with the Hall element plate, the focusing assembly drives the magnetic bead to pass through the Hall element plate under the action of the driving assembly, and the position where the Hall voltage generated by the Hall element plate under the influence of the magnetic field of the magnetic bead is the maximum is the zero position of the lens. In the focusing process, accurate positioning of the zero point of the lens can be realized by using the combination of the magnetic bead and the Hall element plate, a mode of using a mechanical dead point as the zero point in the prior art is replaced, and the Hall element plate can sensitively sense the influence of the magnetic field of the magnetic bead on the Hall voltage, so that the return-to-zero reaction time of the lens is shorter, the positioning is more accurate, and the focusing precision is improved. Therefore, impact vibration is not generated, mechanical wear is avoided, and the focusing accuracy is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of lenses, and particularly relates to a lens zero-position positioning structure. Background Art

[0002] The zero point of a lens generally refers to the optical center of the lens. In the fields of photography and optics, the optical center of a lens is the point where light converges after passing through the lens, and it is also the center point of the image on the imaging plane (such as the sensor of a camera). When the lens is parallel to the imaging plane, the optical center coincides with the actual center point on the imaging plane. If the lens is not parallel to the imaging plane, even if the object is directly in front of the lens, the image will not be at the center of the imaging plane but at a position offset from the center. Therefore, positioning the lens zero point plays an important role in ensuring image quality and precise measurement.

[0003] Due to encoder limitations, most lenses generally use the mechanical dead point, that is, the end of the spiral groove of the focusing component, as the zero position, which will have the following problems: 1. There is an elastic impact near the end, the positioning is inaccurate, and the lens shakes. 2. After long-term use, the zero position changes. 3. Controlling the speed reduction during zeroing will affect the focusing efficiency of the lens.

[0004] Therefore, there are defects in the prior art. Content of the Utility Model

[0005] The purpose of the utility model is to overcome the deficiency of inaccurate zero-position positioning in the above-mentioned prior art, and provides a lens zero-position positioning structure.

[0006] The utility model is realized as follows: A lens zero-position positioning structure is applied to a lens body and its focusing component, and includes: a positioning plate provided on the lens body, a Hall element plate provided on the positioning plate, and a driving component for driving the focusing component to rotate. A magnetic bead adapted to the Hall element plate is provided on the outer wall of the focusing component. The focusing component drives the magnetic bead to pass through the Hall element plate under the action of the driving component. When the magnetic bead passes through the Hall element plate, the position where the magnetic bead is located at the maximum Hall voltage generated by the Hall element plate under the influence of the magnetic field of the magnetic bead is the lens zero-point position.

[0007] Further, the driving component includes a gear set and a focusing motor for driving the gear set to rotate. The gear set includes a driving gear connected to the output shaft of the focusing motor and a driven gear fixed to the focusing component, and the driving gear and the driven gear are meshed with each other.

[0008] Further, there is a gap between the driven gear and the positioning plate, the magnetic bead is provided in the gap, and a part of the Hall element plate extends into the gap to cooperate with the magnetic bead.

[0009] Further, the Hall element board is detachably connected to the positioning board by a plurality of screws.

[0010] A lens zero-position positioning structure provided by the present utility model can achieve precise positioning of the lens zero point by using the combination of a magnetic bead and a Hall element board during the focusing process, replacing the method of using a mechanical dead point as the zero point in the prior art. The Hall element board can sensitively sense the influence of the magnetic field of the magnetic bead on the Hall voltage, making the lens return-to-zero response time shorter and the positioning more accurate. There will be neither impact vibration nor mechanical wear, improving the accuracy of focusing. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0012] The following drawings are only intended to illustrate and explain the present utility model schematically and do not limit the scope of the present utility model.

[0013] Figure 1 It is a schematic structural diagram provided by the present utility model.

[0014] Figure 2 It is an exploded structural diagram provided by the present utility model.

[0015] Explanation of the reference numerals in the drawings: 1, lens body; 2, focusing assembly; 3, positioning board; 4, Hall element board; 5, driving assembly; 51, focusing motor; 52, driving gear; 53, driven gear; 6, magnetic bead. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following will further describe the present utility model in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and do not limit the present utility model.

[0017] Please refer to Figure 1 - Figure 2 , which is a lens zero-position positioning structure disclosed by the utility model and is applied to the lens body 1 and its focusing assembly 2. In this embodiment, the focal length of the lens body 1 is adjusted by the rotation of the focusing assembly 2 to achieve the focusing function of the lens body 1. Among them, the internal structure cooperation between the focusing assembly 2 and the lens body 1 is the prior art and will not be elaborated in detail in this embodiment.

[0018] The zero-position positioning structure of the lens specifically includes: a positioning plate 3 provided on the lens body 1, a Hall element plate 4 provided on the positioning plate 3, and a driving component 5 for driving the focusing component 2 to rotate. The positioning plate 3 and the lens body 1 are fixed in position. The driving component 5 preferably but is not limited to including a gear set and a focusing motor 51 for driving the gear set to rotate. The body part of the focusing motor 51 is fixedly connected to the positioning plate 3, so that the focusing motor 51 and the lens body 1 are fixed in position relative to each other, ensuring stable focusing operations in the subsequent process. The gear set includes a driving gear 52 connected to the output shaft of the focusing motor 51 and a driven gear 53 fixed to the focusing component 2. The driven gear 53 specifically surrounds the periphery of the focusing component 2 for one week to ensure the synchronous rotation of the driven gear 53 and the focusing component 2. The driving gear 52 and the driven gear 53 are meshed with each other. When focusing, the focusing motor 51 is started to drive the driving gear 52 to rotate. The driving gear 52 can drive the rotation of the driven gear 53, and the adjusting component can rotate with the rotation of the driven gear 53 to achieve the effect of automatic focusing.

[0019] Magnetic beads 6 adapted to the Hall element plate 4 are provided on the outer wall of the focusing component 2. Further, a gap is provided between the driven gear 53 and the positioning plate 3. The magnetic beads 6 are provided in the gap, and part of the Hall element plate 4 extends into the gap to cooperate with the magnetic beads 6. The gap provides space for the precise cooperation between the magnetic beads 6 and the Hall element plate 4, improving the accuracy of zero-point positioning. At the same time, the Hall element plate 4 can be detachably connected to the positioning plate 3 by means of several screws, etc. This not only facilitates installation and maintenance, but also facilitates the upgrade of the overall structure or the replacement of components.

[0020] During the rotation of the focusing assembly 2, the magnetic bead 6 also rotates along with the rotation of the focusing assembly 2, that is, the focusing assembly 2 drives the magnetic bead 6 to pass through the Hall element board 4 under the action of the driving assembly 5. Due to the cooperation between the magnetic bead 6 and the Hall element board 4, the magnetic bead 6 exhibits magnetism under the action of an external magnetic field and forms a magnetic field. The Hall element board 4 utilizes the Hall effect. When the magnetic field generated by the magnetic bead 6 passes through the Hall element board 4, a potential difference is generated at both ends of the element, that is, the Hall element board 4 generates a certain Hall voltage, thereby detecting the presence and intensity of the magnetic field. After debugging, when the magnetic bead 6 passes through the Hall element board 4, the position where the magnetic bead 6 is located at the maximum Hall voltage generated by the Hall element board 4 under the influence of the magnetic field of the magnetic bead 6 is the zero position of the lens. When it is necessary to locate the zero position of the lens, the focusing motor 51 and the gear set cooperate to drive the rotation of the focusing assembly 2. During this process, the magnetic bead 6 also rotates along with the rotation of the focusing assembly 2. Since the Hall element board 4 is on the rotation path of the magnetic bead 6, that is, the magnetic bead 6 passes through the Hall element board 4 through the rotation of the focusing assembly 2. At this time, when the Hall element board 4 detects the magnitude of the Hall voltage generated by itself when the magnetic bead 6 passes through different positions in real time, when the detected generated Hall voltage is the maximum peak value, the Hall element board 4 feeds back the detection result to the focusing motor 51, and the focusing motor 51 then stops driving the rotation of the focusing assembly 2. At this time, the magnetic bead 6 stays at the position corresponding to the maximum Hall voltage generated in the Hall element board 4, that is, the zero position of the lens is successfully located, replacing the method of using a mechanical dead point as the zero point in the prior art. The Hall element board 4 can sensitively sense the influence of the magnetic field of the magnetic bead 6 on the Hall voltage, making the lens return-to-zero response time shorter and the zero position positioning more accurate, improving the accuracy of focusing.

[0021] In addition, there may be an electronic control unit in the entire lens, which is used to receive the detection signal from the Hall element board 4 and control the operation of the focusing motor 51 to achieve automatic focusing.

[0022] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lens zero-position positioning structure, applied to a lens body (1) and a focusing assembly (2) thereof, characterized in that: include: A positioning plate (3) is arranged on the lens body (1), and a Hall element plate (4) and a driving component (5) for driving the focusing component (2) to rotate are arranged on the positioning plate (3); a magnetic bead (6) adapted to the Hall element plate (4) is arranged on the outer wall of the focusing component (2); the focusing component (2) drives the magnetic bead (6) to pass through the Hall element plate (4) under the action of the driving component (5); when the magnetic bead (6) passes through the Hall element plate (4), the position where the Hall voltage generated by the magnetic bead (6) on the Hall element plate (4) is the maximum under the influence of the magnetic field of the magnetic bead (6) is the lens zero point position.

2. The lens zero position positioning structure according to claim 1, characterized in that: The driving assembly (5) comprises a gear set and a focus motor (51) for driving the gear set to rotate, the gear set comprising a driving gear (52) connected to an output shaft of the focus motor (51) and a driven gear (53) fixed to the focus assembly (2), the driving gear (52) and the driven gear (53) being meshed with each other.

3. The lens zero position positioning structure according to claim 2, characterized in that: A gap is provided between the driven gear (53) and the positioning plate (3), the magnetic bead (6) is arranged in the gap, and a portion of the Hall element plate (4) extends into the gap to cooperate with the magnetic bead (6).

4. The lens zero position positioning structure according to claim 1, characterized in that: The Hall element plate (4) is detachably connected to the positioning plate (3) via a plurality of screws.

Images