Lens focusing device

Abstract

The present invention discloses a lens focusing device, comprising: a base; a lens connection seat, which is movably arranged on the base; a guide shaft, which is inserted into the lens connection seat and connected to the base at one end; a motor, which is arranged on the base, and the output end of the motor is connected with a lead screw and can drive the lead screw to rotate, and the length direction of the lead screw is the same as the length direction of the guide shaft; a connecting piece is sleeved on the lead screw, and the connecting piece is connected to the lens connection seat, and the connecting piece can reciprocate along the length direction of the lead screw with the rotation of the lead screw, so as to drive the lens connection seat to reciprocate along the length direction of the guide shaft. The present invention can drive the lens connection seat to reciprocate along the length direction of the guide shaft by controlling the forward and reverse rotation of the motor, so as to achieve the purpose of automatic focusing; the lens connection seat only cooperates with the guide shaft, and the matching surface between the products is small, so it is easier to ensure the accuracy on the mold, which solves the problem that the matching accuracy between the parts of the traditional gear box self-focusing module cannot be balanced.

Description

Technical Field

[0001] The invention relates to the technical field of cameras, and in particular to a lens focusing device. Background Art

[0002] As the lens industry matures and the public's awareness of security increases, the market's requirements for security lenses are getting higher and higher, from the original VGA (Video Graphics Array) to the current 4K lens, the image plane has also evolved from the original 1 / 4" to the current 1 / 1.8" or even larger. This evolution has undoubtedly added a lot of difficulty to the design of the optical system. Under the dual requirements of high pixels and large image plane, the lens back focus is sensitive and the back focus length is shortened. As for the issue of back focus sensitivity, the traditional operation of connecting the lens to the base through threads and manually rotating the lens to focus can no longer meet the accuracy requirements of the optical system, so a high-precision autofocus module is needed to achieve focusing.

[0003] Traditional autofocus modules use a gearbox system to achieve the purpose of self-focusing. However, although the gearbox system has high focusing accuracy, its structure always has a certain draft angle when the existing mold is produced, which leads to a certain gap in the mechanical dead point position at both ends of the autofocus module. The matching accuracy between parts cannot be balanced, and the bottom can often fit but the gap at the end is too large, resulting in shaking and other problems; or the end can fit but the bottom fits too tightly, resulting in jamming and serious loss of step problems. Summary of the invention

[0004] The purpose of the present invention is to provide a lens focusing device, which has strong stability and reliability.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A lens focusing device, comprising:

[0007] Base;

[0008] A lens connection seat, used for connecting a lens, wherein the lens connection seat is movably arranged on the base;

[0009] A guide shaft, the guide shaft is inserted into the lens connecting seat and one end of the guide shaft is connected to the base; and

[0010] A motor is arranged on the base, and the output end of the motor is connected to a lead screw and can drive the lead screw to rotate, and the length direction of the lead screw is the same as the length direction of the guide shaft; a connecting piece is sleeved on the lead screw, and the connecting piece is connected to the lens connecting seat, and the connecting piece can reciprocate along the length direction of the lead screw with the rotation of the lead screw to drive the lens connecting seat to reciprocate along the length direction of the guide shaft.

[0011] In some embodiments, the lens focusing device further includes a stopper for preventing the lens connecting seat from escaping from the guide shaft, the stopper is fixedly connected to the base, and the other end of the guide shaft is connected to the stopper.

[0012] In some embodiments, a through hole is opened on the lens connecting seat, and a spring and a steel ball are arranged in the through hole, and the steel ball abuts against the connecting piece; the length direction of the spring is the same as the length direction of the guide shaft, and one end of the spring is connected to the steel ball, and the other end abuts or is connected to the limit piece.

[0013] In some embodiments, a guide blind hole is provided on the limiting member corresponding to the through hole, and the other end of the spring extends into the guide blind hole.

[0014] In some embodiments, the lens connecting seat includes a connecting seat body for connecting the lens and a connecting portion protruding from the connecting seat body, and the guide shaft passes through the connecting portion.

[0015] In some embodiments, the base is provided with a accommodating space, the lens connecting seat is at least partially disposed in the accommodating space, a notch is provided on a side wall of the accommodating space, and the connecting member is passed through the notch and connected to the lens connecting seat.

[0016] In some embodiments, the lens focusing device further includes a guide rod for guiding the connecting member, and a length direction of the guide rod is the same as a length direction of the lead screw.

[0017] In some embodiments, the lens focusing device further includes a mounting frame connected to the base, the motor and the guide rod are arranged on the mounting frame, and the connecting member is located in the mounting frame.

[0018] In some embodiments, the base is provided with a connection interface for connecting to an IR-cut.

[0019] In some embodiments, the motor is a stepper motor.

[0020] The lens focusing device of the present invention has at least the following beneficial effects: by controlling the forward and reverse rotation of the motor, the lens connecting seat can be driven to reciprocate along the length direction of the guide shaft, thereby achieving the purpose of automatic focusing; in the lens focusing device of the above structure, the lens connecting seat only cooperates with the guide shaft, and the matching surface between the products is small, so it is easier to ensure the accuracy on the mold, thereby solving the problem that the matching accuracy between the parts of the traditional gear box self-focusing module cannot be balanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a lens focusing device provided in an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A top view of the lens focusing device shown;

[0023] Figure 3 for Figure 1 The structure diagram of the lens focusing device after being connected to the lens is shown;

[0024] Figure 4 for Figure 3 An exploded schematic diagram of the lens focusing device and the lens is shown;

[0025] Figure 5 for Figure 2 The lens focusing device shown is a partial structural schematic diagram after the base is omitted;

[0026] Figure 6 for Figure 5 A cross-sectional view of the lens focusing device along the AA direction;

[0027] Figure 7 A schematic structural diagram of a base provided in an embodiment of the present invention;

[0028] Figure 8 A schematic diagram of the structure of a lens connector provided in an embodiment of the present invention;

[0029] Fig. 9 A schematic diagram of the structure of a driving mechanism provided in an embodiment of the present invention;

[0030] Description of Figure Numbers:

[0031] Base 10, accommodating space 11, notch 12, connection interface 13, lens connecting seat 20, connecting seat body 21, connecting part 22, guide shaft 30, motor 41, screw 42, connecting piece 43, guide rod 44, mounting frame 45, limit piece 50, spring 61, steel ball 62, fastener 70, lens 100, side plate 451, connecting plate 452. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0033] This embodiment provides a lens focusing device, such as Figures 1 to 9 As shown, the lens focusing device includes a base 10, a lens connecting seat 20, a guide shaft 30 and a motor 41, wherein the lens connecting seat 20 is used to connect the lens 100, and the lens connecting seat 20 is movably arranged on the base 10; the guide shaft 30 is used to position the lens connecting seat 20 and guide the movement of the lens connecting seat 20, the guide shaft 30 is penetrated in the lens connecting seat 20 and one end of the guide shaft 30 is connected to the base 10; the motor 41 is arranged on the base 10, the output end of the motor 41 is connected to the lead screw 42 and can drive the lead screw 42 to rotate, and the length direction of the lead screw 42 is the same as the length direction of the guide shaft 30; a connecting member 43 is sleeved on the lead screw 42, the connecting member 43 is connected to the lens connecting seat 20, and the connecting member 43 can reciprocate along the length direction of the lead screw 42 with the rotation of the lead screw 42, so as to drive the lens connecting seat 20 to reciprocate along the length direction of the guide shaft 30.

[0034] The above-mentioned lens focusing device can drive the lens connecting seat 20 to reciprocate along the length direction of the guide shaft 30 by controlling the forward and reverse rotation of the motor 41, thereby achieving the purpose of automatic focusing; in the lens focusing device of the above-mentioned structure, the lens connecting seat 20 only cooperates with the guide shaft 30, and the matching surface between the products is small, so it is easier to ensure the accuracy on the mold, thereby solving the problem of uneven matching accuracy between parts of the traditional gear box self-focusing module.

[0035] Optionally, the motor 41 may be a servo motor or a stepper motor, preferably a stepper motor, which can be controlled more accurately.

[0036] like Figure 7 As shown, in some embodiments, the base 10 is provided with a accommodating space 11, and the lens connecting seat 20 is at least partially arranged in the accommodating space 11, so as to reduce the overall occupied space of the lens focusing device; a notch 12 is provided on the side wall of the accommodating space 11, and the connecting member 43 is passed through the notch 12 and connected to the lens connecting seat 20.

[0037] like Figure 7 As shown, the base 10 is provided with a connection interface 13 for connecting to an IR-cut (IR-cut is a dual filter switcher). The IR-cut is a single body and whether it needs to be installed can be determined according to usage requirements.

[0038] In some embodiments, the lens focusing device further includes an IR-cut, which is mounted at the connection interface 13 on the base 10. It is understandable that reducing the thickness of the IR-cut can increase the IR-cut when the lens back focal length is short, thus saving back focal space to a great extent.

[0039] like Figure 8 As shown, in some embodiments, the lens connecting seat 20 includes a connecting seat body 21 for connecting the lens and a connecting portion 22 protruding from the connecting seat body 21, and the guide shaft 30 is passed through the connecting portion 22. The connection stability between the lens connecting seat 20 and the lens 100 is ensured by the connecting seat body 21. The connecting portion 22 is not affected by the connecting seat body 21, so the connecting portion 22 can be set as small as possible, thereby further reducing the assembly surface of the lens connecting seat 20 and the guide shaft 30.

[0040] In such Figure 8 In the illustrated embodiment, there are two connecting parts 22, which are arranged opposite to each other, and the connecting member 43 is connected to one of the connecting parts 22; there are also two guide shafts 30, which are correspondingly passed through the two connecting parts 22 and arranged opposite to each other, so as to improve the movement stability of the lens connecting seat 20 during the focusing process.

[0041] In some embodiments, the lens focusing device further includes a stopper 50, which is fixedly connected to the base 10 and connected to the other end of the guide shaft 30. The stopper 50 can prevent the lens connection seat 20 from being disengaged from the guide shaft 30 when the lens connection seat 20 moves along the length direction of the guide shaft 30, so as to ensure the safety of the lens 100 connected to the lens connection seat 20. Optionally, the stopper 50 and the lens connection seat 20 can be detachably connected by a fastener 70 (such as a screw, a bolt and a nut assembly).

[0042] Traditional autofocus modules have a return error problem that cannot be eliminated. To solve this problem, Figure 6 As shown, the lens focusing device of the present invention is provided with a through hole on the lens connecting seat 20, in which a spring 61 and a steel ball 62 are provided, and the steel ball 62 abuts against the connecting piece 43; the length direction of the spring 61 is the same as the length direction of the guide shaft 30, and one end of the spring 61 is connected to the steel ball 62, and the other end of the spring 61 abuts against or is connected to the limit member 50. During the entire process that the lens connecting seat 20 moves along the length direction of the guide shaft 30, the spring 61 always has a thrust on the connecting piece 43, thereby effectively avoiding the problem of return difference.

[0043] Specifically, after the connecting member 43 is connected to the lens connecting seat 20, a steel ball 62 and a spring 61 are installed in the through hole on the lens connecting seat 20, wherein the steel ball 62 presses against the connecting member 43, one end of the spring 61 presses against the steel ball 62, and the other end of the spring 61 presses against the limit member 50. During the entire process that the lens connecting seat 20 moves along the length direction of the guide shaft 30, the spring 61 always exerts a thrust on the connecting member 43, thereby effectively avoiding the problem of return difference.

[0044] In some embodiments, a guide blind hole is provided on the corresponding through hole of the limit member 50, and the other end of the spring 61 extends into the guide blind hole, so that the guide blind hole can accommodate a part of the spring 61, thereby guiding the telescopic movement of the spring 61, so that the elastic restoring force of the spring 61 always remains in the same straight line, thereby ensuring the accuracy of focusing.

[0045] In some embodiments, the lens focusing device also includes a guide rod 44 for guiding the connecting member 43. The length direction of the guide rod 44 is the same as the length direction of the lead screw 42. The guide rod 44 allows the connecting member 43 to move more smoothly along the length direction of the lead screw 42, which helps to improve the focusing accuracy.

[0046] Furthermore, the lens focusing device also includes a mounting frame 45 connected to the base 10, the motor 41 and the guide rod 44 are arranged on the mounting frame 45, and the connecting member 43 is located in the mounting frame 45. By designing the mounting frame 45, the motor 41, the lead screw 42, the guide rod 44 and the connecting member 43 can be combined into a driving module. When assembling the lens focusing device, the driving module is installed on the base 10 to realize modular assembly, which makes disassembly and assembly more convenient, and is also convenient for storage and transportation.

[0047] Specifically, Fig. 9 As shown, the mounting frame 45 includes two side plates 451 arranged opposite to each other and a connecting plate 452 connecting the two side plates 451, and the connecting plate 452 is detachably connected to the base 10 by fasteners (such as screws, bolt and nut assemblies); the connecting member 43 is located between the two side plates 451, and the two ends of the guide rod 44 are respectively connected to the two side plates 451; the motor 41 is installed on one of the side plates 451, and a through hole is provided on the side plate 451 corresponding to the lead screw 42, and the lead screw 42 passes through the through hole.

[0048] It should be noted that when a part is referred to as being "fixed to" another part, it may be directly on the other part or there may be a central part. When a part is considered to be "connected" to another part, it may be directly connected to the other part or there may be a central part at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only and do not represent the only implementation method.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0050] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A lens focusing device, characterized in that: include: Base (10); A lens connecting seat (20) used for connecting the lens (100), wherein the lens connecting seat (20) is movably arranged on the base (10); a guide shaft (30), the guide shaft (30) being inserted into the lens connecting seat (20) and having one end connected to the base (10); and A motor (41) is arranged on the base (10); an output end of the motor (41) is connected to a lead screw (42) and can drive the lead screw (42) to rotate; the length direction of the lead screw (42) is the same as the length direction of the guide shaft (30); a connecting piece (43) is sleeved on the lead screw (42); the connecting piece (43) is connected to the lens connecting seat (20); the connecting piece (43) can reciprocate along the length direction of the lead screw (42) with the rotation of the lead screw (42), so as to drive the lens connecting seat (20) to reciprocate along the length direction of the guide shaft (30); The lens focusing device further comprises a stopper (50) for preventing the lens connecting seat (20) from falling off the guide shaft (30), the stopper (50) being fixedly connected to the base (10), and the other end of the guide shaft (30) being connected to the stopper (50); A through hole is provided on the lens connecting seat (20), and a spring (61) and a steel ball (62) are provided in the through hole, and the steel ball (62) abuts against the connecting member (43); the length direction of the spring (61) is the same as the length direction of the guide shaft (30), and one end of the spring (61) is connected to the steel ball (62), and the other end abuts against or is connected to the limiting member (50).

2. The lens focusing device according to claim 1, characterized in that: A guide blind hole is provided on the limiting member (50) corresponding to the through hole, and the other end of the spring (61) extends into the guide blind hole.

3. The lens focusing device according to claim 1, characterized in that: The lens connecting seat (20) comprises a connecting seat body (21) for connecting the lens and a connecting portion (22) protruding from the connecting seat body (21), and the guide shaft (30) is inserted into the connecting portion (22).

4. The lens focusing device according to claim 1, characterized in that: The base (10) is provided with a housing space (11), the lens connecting seat (20) is at least partially arranged in the housing space (11), a notch (12) is provided on a side wall of the housing space (11), and the connecting member (43) is passed through the notch (12) and connected to the lens connecting seat (20).

5. The lens focusing device according to claim 1, characterized in that: The lens focusing device also includes a guide rod (44) for guiding the connecting member (43), and the length direction of the guide rod (44) is the same as the length direction of the lead screw (42).

6. The lens focusing device according to claim 5, characterized in that: The lens focusing device also includes a mounting frame (45) connected to the base (10), the motor (41) and the guide rod (44) are arranged on the mounting frame (45), and the connecting member (43) is located in the mounting frame (45).

7. The lens focusing device according to claim 1, characterized in that: The base (10) is provided with a connection interface (13) for connecting to an IR-cut.

8. The lens focusing device according to any one of claims 1 to 7, characterized in that: The motor (41) is a stepping motor.

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