High-stability automatic focusing module

Abstract

The utility model discloses a high-stability automatic focusing module, which comprises a fixed base, a gear motor assembly, a movable focusing ring and a movable mirror frame, the movable focusing ring is sleeved on the periphery of a cylinder part of the base and is driven by the gear motor assembly, and the movable mirror frame is movably embedded in a light through hole of the base; the movable mirror frame is provided with a guide column, the guide column and the movable mirror frame are of an integrated structure through injection molding, and the outer end of the guide column penetrates through the vertical through groove and extends into the spiral groove. A magnetic attraction assembly is arranged between the fixed base and the movable mirror frame, the magnetic attraction assembly comprises a first magnetic attraction piece fixed to the inner wall of a light through hole of the base in a dispensing mode and a second magnetic attraction piece fixed to the outer side wall of the movable mirror frame in a dispensing mode, and the first magnetic attraction piece and the second magnetic attraction piece are arranged in a staggered mode in the Z-axis direction; and the movable mirror frame is subjected to the combined action of the radial retention force and the axial retention force under the magnetic action of the first magnetic attraction piece on the second magnetic attraction piece. By means of the structural design, the focusing device has the advantages of being novel in design, good in stability and reliability and high in focusing precision.

Description

Technical Field

[0001] The utility model relates to the technical field of optical devices, in particular to an automatic focusing module with high stability. Background Art

[0002] The Chinese utility model patent with the patent number ZL202123135119.4 and the patent name of a detachable automatic focusing MTV lens module actually discloses an automatic focusing module. Specifically, the detachable automatic focusing MTV lens module includes a fixed base, a fixed sleeve connected to the fixed base, an activity lens frame embedded in the sleeve accommodation cavity at the core of the fixed sleeve, and a compression spring located on the upper end side of the activity lens frame. A fixed cover plate is screwed and fastened to the upper end surface of the fixed sleeve. The upper and lower end parts of the compression spring are respectively abutted against the corresponding fixed cover plate and the activity lens frame. The activity lens frame is provided with a lens frame convex column protruding radially outwards. The lens frame convex column and the activity lens frame are of an integral structure. The fixed sleeve is provided with a sleeve vertical through groove that radially penetrates completely and extends vertically corresponding to the lens frame convex column. An outer adjustment ring in a circular ring shape is sleeved outside the fixed sleeve. A spiral groove extending spirally is provided on the inner circumferential surface of the outer adjustment ring corresponding to the lens frame convex column. The outer end part of the lens frame convex column passes through the sleeve vertical through groove and the outer end part of the lens frame convex column is embedded in the spiral groove. A reduction motor assembly is installed beside the outer adjustment ring on the fixed base, and the reduction motor assembly is drivingly connected to the outer adjustment ring. The reduction motor assembly includes a reduction gearbox housing screwed and fastened to the upper surface of the fixed base. A reduction gearbox accommodation cavity opening towards the outer adjustment ring side is formed inside the reduction gearbox housing. A reduction gear set is embedded in the reduction gearbox accommodation cavity. A stepping motor is screwed and fastened to the outer surface of the reduction gearbox housing. The outer adjustment ring is provided with an outer gear part. The outer gear part and the outer adjustment ring are of an integral structure. The input end gear of the reduction gear set is installed on the power output shaft of the stepping motor, and the output end gear of the reduction gear set meshes with the outer gear part of the outer adjustment ring.

[0003] In the process of the above detachable automatic focusing MTV lens module realizing the focusing action, the stepping motor drives the outer gear part of the outer adjustment ring through the reduction gear set, so that the outer adjustment ring rotates relative to the fixed sleeve. In the process of the outer adjustment ring rotating relative to the fixed sleeve, the outer adjustment ring drives the lens frame convex column of the activity lens frame to move up and down through the spiral groove, and then the activity lens frame moves up and down relative to the fixed sleeve, so as to realize the up and down movement of the camera lens, and then perform the focusing action.

[0004] It should be noted that for the above detachable automatic focusing MTV lens module, it has the following defects, specifically:

[0005] Defect 1: The compression spring keeps pressing the movable frame downward. When the external impact and shaking are eliminated, the elastic force of the compression spring will cause the movable frame to reset to the fixed state to achieve the function of no crosstalk and no defocus in the Z-axis of the movable frame. However, since there is no radial holding force acting on the movable frame and the movable frame is movably installed in the sleeve accommodating cavity of the fixed sleeve, there is inevitably a radial gap between the movable frame and the fixed sleeve. Without the action of the radial holding force, when the movable frame shakes due to external impact, the movable frame will have a problem of radial crosstalk. Even when the external impact and shaking are eliminated, the movable frame still will not reset to the concentric state with the light passing hole, resulting in poor stability and accuracy in use. Summary of the Invention

[0006] The purpose of the present invention is to provide a highly stable automatic focusing module for the deficiencies of the prior art. The highly stable automatic focusing module has a novel structural design, good stability and reliability, and high focusing accuracy.

[0007] To achieve the above object, the present invention is realized through the following technical solutions.

[0008] A highly stable automatic focusing module includes a fixed base, a reduction motor assembly, a movable focusing ring, and a movable frame. The fixed base is provided with a base cylindrical portion in the shape of a cylinder, and a base light passing hole vertically penetrating and in the shape of a circular hole is opened in the core of the base cylindrical portion. The movable focusing ring is sleeved outside the base cylindrical portion, and the movable frame is movably embedded in the base light passing hole.

[0009] The reduction motor assembly is screwed to the fixed base and is located beside the base cylindrical portion, and the reduction motor assembly is drivingly connected to the movable focusing ring.

[0010] The movable frame is provided with guide posts protruding radially outward and extending. The guide posts and the movable frame are integrally formed by injection molding. The base cylindrical portion is provided with a vertical through groove radially penetrating and opening upward corresponding to the guide posts of the movable frame, and the inner circumferential surface of the movable focusing ring is provided with a spiral groove spirally extending and opening upward corresponding to the guide posts of the movable frame. The outer end of the guide post passes through the vertical through groove and extends into the spiral groove.

[0011] A magnetic attraction component is installed between the fixed base and the movable frame. The magnetic attraction component includes a first magnetic attraction member fixed to the inner wall of the base light passing hole by dispensing glue and a second magnetic attraction member fixed to the outer side wall of the movable frame by dispensing glue. The first magnetic attraction member and the second magnetic attraction member are arranged in a staggered manner in the Z-axis direction.

[0012] The magnetic force of the first magnetic attraction member on the second magnetic attraction member causes the movable frame to be subjected to the combined action of radial holding force and axial holding force.

[0013] Wherein, the first magnetic attraction member includes a plurality of base magnets distributed in a circular array with the axis of the base light hole as the center, and each base magnet is respectively fastened to the inner wall of the base light hole;

[0014] The second magnetic attraction component includes a plurality of frame magnets distributed in a circular array with the axis of the movable frame as the center, and each frame magnet is fastened to the outer wall of the movable frame; the number of base magnets is consistent with the number of frame magnets, and the first magnet group and the second magnet group are staggered in the Z-axis direction.

[0015] Wherein, the first magnetic attraction member includes a plurality of single magnets distributed in a circular array with the axis of the light-through hole of the base as the center, and each single magnet is respectively fastened and installed on the inner wall of the light-through hole of the base;

[0016] The second magnetic attraction member is an annular iron member in the shape of a circular ring. The annular iron member is set and fastened to the outer side wall of the movable mirror frame, and the annular magnet is coaxially arranged with the movable mirror frame.

[0017] Wherein, the first magnetic attraction member is an annular iron member in the shape of a circular ring, the annular iron member is fixedly mounted on the inner wall of the light-through hole of the base and the annular iron member is coaxially arranged with the light-through hole of the base;

[0018] The second magnetic attraction member includes a plurality of single magnets distributed in a circular array with the axis of the movable mirror frame as the center, and each single magnet is respectively fastened to the outer side wall of the movable mirror frame.

[0019] Wherein, a limiting member is installed at the upper end of the cylindrical portion of the base, and the limiting member is in contact with the upper surface of the movable focusing ring and the upper surface of the first magnetic attraction member respectively.

[0020] Compared with the prior art, the utility model has the following beneficial effects, specifically: due to the magnetic force of the first magnetic attraction component on the second magnetic attraction component, the movable mirror frame is subjected to the combined action of the radial holding force and the axial holding force, and the axial holding force can effectively ensure that the movable mirror frame is axially reset to a fixed state when the external impact and shaking are eliminated, so as to avoid the axial movement and displacement of the movable mirror frame, thereby ensuring that the movable mirror frame has no movement and no false focus in the Z-axis direction; the radial holding force can effectively ensure that the movable mirror frame is reset to a concentric state with the light hole of the base when the external impact and shaking are eliminated, so as to avoid the radial movement and displacement of the movable mirror frame, thereby ensuring that the movable mirror frame has no radial movement. The magnetic attraction component of the utility model can make the movable mirror frame be subjected to the simultaneous action of the axial holding force and the radial holding force when in use, and after the external impact and shaking are eliminated, the movable mirror frame has no axial and radial movement and displacement, which can effectively improve the stability and reliability of the focusing module and the high focusing accuracy; therefore, the high-stability automatic focusing module of the utility model has the advantages of novel structural design, good stability and reliability, and high focusing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present utility model will be further described below with reference to the attached drawings, but the embodiments in the drawings do not constitute any limitation to the present utility model.

[0022] Figure 1 It is a schematic structural diagram of the present utility model.

[0023] Figure 2 is Figure 1 exploded schematic diagram of.

[0024] Figure 3 It is a schematic cross-sectional view of the present utility model.

[0025] Figure 4 It is a schematic structural diagram of another embodiment of the magnetic attraction assembly of the present utility model.

[0026] Figure 5 It is a schematic structural diagram of yet another embodiment of the magnetic attraction assembly of the present utility model.

[0027] Figure 6 It is a schematic structural diagram of another embodiment of the present utility model.

[0028] In Figures 1 to 6 include:

[0029] 1 - fixed base; 11 - base cylindrical part; 12 - base light passing hole; 13 - vertical through groove; 2 - deceleration motor assembly; 3 - movable focusing ring; 31 - spiral groove; 4 - movable lens frame; 41 - guide post; 51 - first magnetic attraction member; 52 - second magnetic attraction member; 53 - base magnet; 54 - lens frame magnet; 55 - monomer magnet; 56 - annular iron piece; 6 - limiting member. Specific embodiments

[0030] The present utility model will be described below in conjunction with specific embodiments.

[0031] Embodiment 1, as Figures 1 to 6 shown, a highly stable automatic focusing module includes a fixed base 1, a deceleration motor assembly 2, a movable focusing ring 3, and a movable lens frame 4. The fixed base 1 is provided with a base cylindrical part 11 in a cylindrical shape, and a base light passing hole 12 vertically penetrating and in a circular hole shape is provided in the core of the base cylindrical part 11. The movable focusing ring 3 is sleeved outside the base cylindrical part 11, and the movable lens frame 4 is movably embedded in the base light passing hole 12.

[0032] Among them, as Figure 1 , Figure 2 and Figure 5 shown, the deceleration motor assembly 2 is screwed to the fixed base 1 and is located beside the base cylindrical part 11, and the deceleration motor assembly 2 is drivingly connected to the movable focusing ring 3.

[0033] Further, as shown in Figures 2 to 5 , the movable lens frame 4 is provided with guide posts 41 protruding radially outward. The guide posts 41 are integrally injection-molded with the movable lens frame 4. The base cylinder portion 11 is provided with vertical through grooves 13 that radially penetrate and open upward corresponding to the guide posts 41 of the movable lens frame 4. The inner circumferential surface of the movable focusing ring 3 is provided with spiral grooves 31 that spiral and open upward corresponding to the guide posts 41 of the movable lens frame 4. The outer end of the guide post 41 passes through the vertical through groove 13 and extends into the spiral groove 31.

[0034] Furthermore, as shown in Figures 2 to 5 , a magnetic attraction assembly is installed between the fixed base 1 and the movable lens frame 4. The magnetic attraction assembly includes a first magnetic attraction member 51 adhesively fixed to the inner wall of the base light passing hole 12 and a second magnetic attraction member 52 adhesively fixed to the outer side wall of the movable lens frame 4. The first magnetic attraction member 51 and the second magnetic attraction member 52 are arranged in a dislocation in the Z-axis direction; the magnetic force of the first magnetic attraction member 51 on the second magnetic attraction member 52 causes the movable lens frame 4 to be jointly affected by a radial holding force and an axial holding force.

[0035] Specifically, as shown in Figure 2 and Figure 3 , the first magnetic attraction member 51 includes a plurality of base magnets 53 distributed in a circumferential array centered on the axis of the base light passing hole 12. Each base magnet 53 is fixedly installed on the inner wall of the base light passing hole 12; the second magnetic attraction member 52 includes a plurality of lens frame magnets 54 distributed in a circumferential array centered on the axis of the movable lens frame 4. Each lens frame magnet 54 is fixedly installed on the outer side wall of the movable lens frame 4; the number of base magnets 53 is the same as the number of lens frame magnets 54, and the first magnet group and the second magnet group are arranged in a dislocation in the Z-axis direction.

[0036] It should be explained that all the base magnets 53 in the first magnetic attraction member 51 are horizontally aligned, and all the lens frame magnets 54 in the second magnetic attraction member 52 are horizontally aligned. As shown in Figure 3 , there is a height difference H between the central position height of the first magnetic attraction member 51 and the central position height of the second magnetic attraction member 52 to achieve the dislocation arrangement of the first magnetic attraction member 51 and the second magnetic attraction member 52 in the Z-axis direction. Also, the number of base magnets 53 is the same as the number of lens frame magnets 54, and each base magnet 53 is radially aligned with one lens frame magnet 54.

[0037] For the highly stable auto-focus module of this first embodiment, during the process of its focus adjustment operation, the reduction motor assembly 2 drives the movable focus adjustment ring 3 to rotate relative to the base cylinder part 11. The rotating movable focus adjustment ring 3 acts on the guide post 41 through its spiral groove 31 and causes the guide post 41 to move up and down relative to the vertical through groove 13 of the base cylinder part 11. The vertical channel guides the up and down movement of the guide post 41. The guide post 41 that moves up and down relative to the base cylinder part 11 drives the movable lens frame 4 to move up and down synchronously, thereby realizing the focus adjustment operation.

[0038] It should be noted that during the operation of this first embodiment, there is a magnetic force between the first magnetic attraction member 51 and the second magnetic attraction member 52, and this magnetic force can be an attractive force or a repulsive force; when the polarity of the inner surface of the base magnet 53 is the same as the polarity of the outer surface of the lens frame magnet 54, this magnetic force is a repulsive force; when the polarity of the inner surface of the base magnet 53 is opposite to the polarity of the outer surface of the lens frame magnet 54, this magnetic force is an attractive force. Since the first magnetic attraction member 51 and the second magnetic attraction member 52 are arranged with a dislocation in the Z-axis direction, the magnetic force between each base magnet 53 and the corresponding lens frame magnet 54 can be decomposed into a radial acting force and an axial acting force. This radial acting force can form a radial holding force acting on the movable lens frame 4, and this axial acting force can form an axial holding force acting on the movable lens frame 4.

[0039] For the axial holding force formed by the magnetic force between the first magnetic attraction member 51 and the second magnetic attraction member 52, this axial holding force can effectively ensure that the movable lens frame 4 axially resets to a fixed state when the external impact and shaking are eliminated, so as to avoid the axial crosstalk and displacement of the movable lens frame 4, and further ensure that the movable lens frame 4 has no crosstalk and no defocus in the Z-axis direction. For the radial holding force formed by the magnetic force between the first magnetic attraction member 51 and the second magnetic attraction member 52, since the multiple base magnets 53 of the first magnetic attraction member 51 are distributed in a circular array and the multiple lens frame magnets 54 of the second magnetic attraction member 52 are also distributed in a circular array, the movable lens frame 4 will be subjected to the action of multiple radially distributed forces. The above radial holding force makes the movable lens frame 4 in a magnetic levitation state, and the above radial holding force can effectively ensure that the movable lens frame 4 resets to a concentric state with the base light passing hole 12 when the external impact and shaking are eliminated, so as to avoid the radial crosstalk and displacement of the movable lens frame 4, and further ensure that the movable lens frame 4 has no crosstalk in the radial direction.

[0040] For the magnetic attraction component of this first embodiment, it can enable the movable lens frame 4 to be simultaneously acted on by the axial holding force and the radial holding force during use. After the external impact and shaking are eliminated, the movable lens frame 4 has no crosstalk and displacement in both the axial and radial directions, which can effectively improve the stable reliability and high focusing accuracy of the focus adjustment module; therefore, the highly stable auto-focus module of this first embodiment has the advantages of novel structural design, good stable reliability, and high focusing accuracy.

[0041] Embodiment 2, such asFigure 4 As shown in the figure, the difference between the second embodiment and the first embodiment is that the first magnetic attraction member 51 includes a plurality of single magnets 55 that are annularly arrayed around the axis of the base light-passing hole 12, and each single magnet 55 is fixedly installed on the inner wall of the base light-passing hole 12.

[0042] Among them, the second magnetic attraction member 52 is an annular iron member 56 in the shape of a ring. The annular iron member 56 is sleeved and fixedly installed on the outer side wall of the movable spectacle frame 4, and the annular magnet is coaxially arranged with the movable spectacle frame 4.

[0043] For the magnetic attraction assembly of the second embodiment, there is a magnetic attraction force between each single magnet 55 of the first magnetic attraction member 51 and the annular iron member 56; since the first magnetic attraction member 51 of the fixed base 1 and the annular iron member 56 on the movable spectacle frame 4 are arranged in a staggered manner in the Z-axis direction, the magnetic attraction force between each single magnet 55 and the annular iron member 56 can be decomposed into a radial acting force and an axial acting force. The radial acting force can form a radial holding force acting on the movable spectacle frame 4, and the axial acting force can form an axial holding force acting on the movable spectacle frame 4.

[0044] Embodiment Three, as Figure 5 shown, the difference between the third embodiment and the first embodiment is that the first magnetic attraction member 51 is an annular iron member 56 in the shape of a ring. The annular iron member 56 is fixedly installed on the inner wall of the base light-passing hole 12 and the annular iron member 56 is coaxially arranged with the base light-passing hole 12.

[0045] Among them, the second magnetic attraction member 52 includes a plurality of single magnets 55 that are annularly arrayed around the axis of the movable spectacle frame 4, and each single magnet 55 is fixedly installed on the outer side wall of the movable spectacle frame 4.

[0046] For the magnetic attraction assembly of the third embodiment, there is a magnetic attraction force between each single magnet 55 of the second magnetic attraction member 52 and the annular iron member 56; since the second magnetic attraction member 52 of the movable spectacle frame 4 and the annular iron member 56 on the fixed base 1 are arranged in a staggered manner in the Z-axis direction, the magnetic attraction force between each single magnet 55 and the annular iron member 56 can be decomposed into a radial acting force and an axial acting force. The radial acting force can form a radial holding force acting on the movable spectacle frame 4, and the axial acting force can form an axial holding force acting on the movable spectacle frame 4.

[0047] Embodiment Four, as Figure 1 、 Figure 2 、 Figure 3 and Figure 6 shown, the difference between the fourth embodiment and the first embodiment is that a limiting member 6 is installed at the upper end of the base cylindrical portion 11, and the limiting member 6 is in contact with the upper surface of the movable focusing ring 3 and the upper surface of the first magnetic attraction member 51 respectively.

[0048] For the limiting member 6 of the fourth embodiment, on the one hand, it can limit the upper surface of the movable focusing ring 3 so that the movable focusing ring 3 stably rotates and sleeves around the outer periphery of the base cylinder part 11; on the other hand, it can limit the first magnetic member 51 to ensure that the first magnetic member 51 is stably and reliably installed on the inner wall of the base light passing hole 12.

[0049] The above content is only the preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present invention.

Claims

1. An auto-focus module with high stability, comprising a fixed base (1), a reduction motor assembly (2), a movable focusing ring (3), and a movable lens frame (4). The fixed base (1) is provided with a base cylindrical portion (11) in a cylindrical shape. A base through-hole (12) vertically penetrating and in a circular hole shape is provided in the core of the base cylindrical portion (11). The movable focusing ring (3) is sleeved around the outer periphery of the base cylindrical portion (11). The movable lens frame (4) is movably embedded in the base through-hole (12). The reduction motor assembly (2) is screwed to the fixed base (1) and is located beside the base cylindrical portion (11). The reduction motor assembly (2) is drivingly connected to the movable focusing ring (3). The movable lens frame (4) is provided with a guide post (41) protruding radially outward. The guide post (41) and the movable lens frame (4) are integrally injection-molded. The base cylindrical portion (11) is provided with a vertical through-slot (13) radially penetrating and opening upward corresponding to the guide post (41) of the movable lens frame (4). A spiral groove (31) spirally extending and opening upward is provided on the inner circumferential surface of the movable focusing ring (3) corresponding to the guide post (41) of the movable lens frame (4). The outer end of the guide post (41) passes through the vertical through-slot (13) and extends into the spiral groove (31). Characterized in that: A magnetic attraction assembly is installed between the fixed base (1) and the movable lens frame (4). The magnetic attraction assembly includes a first magnetic attraction member (51) adhesively fixed to the inner wall of the base through-hole (12) and a second magnetic attraction member (52) adhesively fixed to the outer side wall of the movable lens frame (4). The first magnetic attraction member (51) and the second magnetic attraction member (52) are arranged in a staggered manner in the Z-axis direction. The magnetic force of the first magnetic attraction member (51) on the second magnetic attraction member (52) causes the movable lens frame (4) to be subjected to the combined action of a radial holding force and an axial holding force.

2. The automatic focusing module with high stability according to claim 1, wherein: The first magnetic attraction member (51) includes a plurality of base magnets (53) annularly arrayed around the axis of the base through-hole (12). Each base magnet (53) is fixedly installed on the inner wall of the base through-hole (12). The second magnetic attraction member (52) includes a plurality of lens frame magnets (54) annularly arrayed around the axis of the movable lens frame (4). Each lens frame magnet (54) is fixedly installed on the outer side wall of the movable lens frame (4). The number of base magnets (53) is the same as the number of lens frame magnets (54). The first magnet group and the second magnet group are arranged in a staggered manner in the Z-axis direction.

3. The automatic focusing module with high stability according to claim 1, characterized in that: The first magnetic attraction member (51) includes a plurality of single magnets (55) annularly arrayed around the axis of the base through-hole (12). Each single magnet (55) is fixedly installed on the inner wall of the base through-hole (12). The second magnetic attraction member (52) is an annular iron piece (56) in a circular ring shape. The annular iron piece (56) is sleeved and fixedly installed on the outer side wall of the movable lens frame (4) and the annular magnet is coaxially arranged with the movable lens frame (4).

4. The high-stability automatic focusing module according to claim 1, characterized in that: The first magnetic attraction member (51) is an annular iron piece (56) in a circular ring shape. The annular iron piece (56) is fixedly installed on the inner wall of the base through-hole (12) and the annular iron piece (56) is coaxially arranged with the base through-hole (12). The second magnetic member (52) includes a plurality of individual magnets (55) that are annularly and arrayedly distributed around the axis of the movable spectacle frame (4), and each individual magnet (55) is fixedly installed on the outer sidewall of the movable spectacle frame (4).

5. An autofocus module with high stability according to claim 1, characterized in that: A limiting member (6) is installed at the upper end of the base cylindrical portion, and the limiting member (6) is in contact with the upper surface of the movable focusing ring (3) and the upper surface of the first magnetic member (51) respectively.

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