Lens zooming mechanism driven by stepping motor and camera lens thereof

Abstract

The utility model discloses a lens zooming mechanism driven by a stepping motor and a camera lens thereof. The lens zoom mechanism includes a lens barrel, a lens holder, and a driving unit. In the driving unit, a C-shaped plate covers the radial outer side of a side wall gap of the lens barrel, a stepping motor is installed at one end of the C-shaped plate, and a circular encoder is installed at the other end of the C-shaped plate and located at the bottom of the side wall gap. And a driving screw of the driving unit is in transmission connection between the stepping motor and the circular encoder through two ends, and drives the lens seat through a transmission piece clamped on a nut in a sleeving manner. The camera lens adopting the lens zooming mechanism is compact in structure and can compensate step loss of the stepping motor.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the electric mechanism of camera equipment, concretely relates to a step motor driven lens zoom mechanism, and further relates to a camera lens comprising the lens zoom mechanism. BACKGROUND

[0002] The camera equipment adopts the zoom mechanism of step motor - lead screw, can give attention to zooming precision, speed, energy consumption and noise, and equipment cost. Patent CN1550813A / 2004, CN103676076A / 2014 and CN105527690A / 2016 disclose relevant technical solutions.

[0003] Relative to other types of lens motor, step motor is relatively large in size.

[0004] The zoom lens of handheld camera should be small and light, and if the above-mentioned zoom mechanism is used, the motor load is usually close to the upper limit and is easy to lose step. The step motor step loss compensation method disclosed in patent CN106060380A / 2016 can make the gun of monitoring camera and the ball machine accurately link. UTILITY MODEL CONTENTS

[0005] The utility model solves the technical problem of how to improve the step motor - lead screw lens zoom mechanism to be applicable to handheld equipment.

[0006] The first aspect of the utility model discloses a step motor driven lens zoom mechanism. The lens zoom mechanism comprises:

[0007] A lens barrel is used to be assembled with other lens barrels as a lens, and two long guide rods axially extend in the inside, and a side wall is provided with an axially extending side wall notch;

[0008] A lens holder is used to install movable lens groups, and is located in the lens barrel and is axially slidably assembled on the two long guide rods; and

[0009] A driving unit is in transmission connection with the lens holder.

[0010] The driving unit comprises:

[0011] A square-shaped plate is covered and fixedly installed on the radial outside of the side wall notch;

[0012] A step motor is fixedly installed on the inside or outside of a bent section of the square-shaped plate and is located at the opening of the side wall notch;

[0013] A round encoder is fixedly installed on the inside or outside of another bent section of the square-shaped plate and is located at the bottom of the side wall notch.

[0014] a lead screw, one end of which is drivingly connected to the stepper motor and the other end of which is drivingly connected to the circular encoder, and a nut being sleeved on the threaded region of the lead screw; and

[0015] a driving member sleeved on the nut and drivingly connected to the lens barrel;

[0016] The stepper motor and the circular encoder are electrically connected to an electronic control unit for controlling the lens.

[0017] In some embodiments of the utility model, the lens zoom mechanism further comprises:

[0018] An inclination sensor, a gyroscope or an attitude sensor is assembled on the lens barrel or the driving unit and electrically connected to the electronic control unit for detecting the angle between the optical axis of the lens and the direction of gravity.

[0019] In some embodiments of the utility model, the stepper motor and the circular encoder are located outside the enclosed space of the H-shaped plate.

[0020] In some embodiments of the utility model, the two sides of the side wall notch are provided with a boss protruding radially outward, and the H-shaped plate is installed on the two bosses.

[0021] In some embodiments of the utility model, the driving unit further comprises a sheet-shaped element through which the electronic control unit is electrically connected.

[0022] In some embodiments of the utility model, the driving member comprises a clamping portion provided with a U-shaped through slot matched with the nut and a poking portion integrally connected to the clamping portion and drivingly connected to the lens barrel. Further, one side wall of the U-shaped through slot is configured as a plurality of clamping jaws distributed axially and elastically swingable radially, and the two clamping jaws located at the two axial ends are closer to the lead screw than the other clamping jaws located between them.

[0023] The second aspect of the utility model discloses a camera lens. The camera lens comprises the lens zoom mechanism and the electronic control unit of the first aspect. The electronic control unit can perform step loss compensation and inclination compensation on the stepper motor. Specifically, an inclination sensor or a gyroscope is used to detect the angle between the optical axis of the camera lens and the direction of gravity, and these sensors are located in at least one of the electronic control unit, the lens barrel and the driving unit.

[0024] The technical scheme of the utility model has the following beneficial effects.

[0025] The utility model discloses a step motor driven lens zoom mechanism and camera lens thereof. The lens zoom mechanism comprises a lens barrel, a lens seat and a driving unit. In the driving unit, the H-shaped plate is covered and installed on the radial outer side of the side wall notch of the lens barrel, the step motor is installed on one end of the H-shaped plate, and the circular encoder is installed on the other end of the H-shaped plate and located at the bottom of the side wall notch. The lead screw of the driving unit is drivingly connected between the step motor and the circular encoder through both ends, and the lens seat is driven through the transmission member sleeved on the nut. The camera lens adopting the lens zoom mechanism is compact in structure and can compensate for the step loss of the step motor. BRIEF DESCRIPTION OF DRAWINGS

[0026] The following drawings should be used in conjunction with the detailed description section.

[0027] Figure 1a and Figure 1b are two perspective views of the lens zoom mechanism in example one;

[0028] Figure 2 is an exploded view of the lens zoom mechanism shown in Figure 1a

[0029] Figure 3 is a perspective view of the lens barrel in example one;

[0030] Figure 4 is an elevation view of the lens seat in example one;

[0031] Figure 5a and Figure 5b are two perspective views of the driving unit in example one;

[0032] Figure 6a and Figure 6b are two perspective views of the transmission member in example one;

[0033] Figure 7 is an electric control principle block diagram of the camera lens in example three;

[0034] Figure 8 is an electric control principle block diagram of the camera lens in example four.

[0035] Figure 1a , Figure 2 and Figure 3 The black arrows in and point to the object being photographed parallel to the optical center axis. DETAILED DESCRIPTION

[0036] The following describes the examples in conjunction with the drawings.

[0037] ​Unless specifically stated, one embodiment, some embodiments and other embodiments are not to be construed as exhaustive or limiting of the scope of the embodiments. The drawings are not to scale and are solely for purposes of illustration. The terms "top," "bottom," "center," "edge," "inner," "outer," "far," "near," "long," "wide," "vertical," "horizontal," "upper," "lower," "front," "back," "left," "right," and the like as can be recited in the description and the appended claims are not to be construed as limiting the scope of the embodiments to a particular orientation or position. The terms "first," "second," "third," and the like as can be recited in the description and the appended claims are not to be construed as limiting the scope of the embodiments to a particular sequence or order. The term "axial" refers to parallel to the optical axis of the lens, and the term "radial" refers to perpendicular to the optical axis of the lens.

[0038] Embodiment One

[0039] A zoom lens mechanism 100 driven by a stepper motor is disclosed.

[0040] The following only introduces the structure related to zoom function, other structure details can refer to the replaceable lens of commercially available cameras.

[0041] Please refer to Figure 1a , Figure 1b , Figure 2 , Figure 3 and Figure 4 , the zoom lens mechanism 100 includes a lens barrel 10, a lens seat 20 and a driving unit 30, and a bearing unit 40 including two long guide rods 41 and a ring seat 42, and an arc-shaped member 81, a pin rod 82 and a plurality of screws 101.

[0042] The lens barrel 10 is a one-piece molded part, having a substantially central axis-symmetrical outer profile, for assembling with other lens barrels into a camera lens, composed of a long and thin cylindrical part 11 and a short and thick annular part 12.

[0043] The front end surface of the cylindrical part 11, facing the object to be photographed, is provided with three circumferentially distributed threaded holes 11a, and three circumferentially distributed notches 11b, for cooperating with the ring seat 42. Correspondingly, the ring seat 42 is provided with three through holes and three axial protrusions 421, assembled on the front end surface of the cylindrical part 11 by three screws 101. The ring seat 42 has a radial width greater than the thickness of the cylindrical part 11, and has an outer diameter consistent with that of the cylindrical part 11, and is provided with a notch on the inner side in the radial direction to cooperate with the following stepper motor 32.

[0044] The rear end surface of the cylindrical part 11, facing the inside of the camera, is located in the radial middle part of the front end surface of the annular part 12, i.e. both the inner and outer side surfaces are stepped transitions. The rear end surface of the annular part 12 is provided with a plurality of concave-convex connecting members for assembly into the camera lens. The radial inner side part of the front end surface of the annular part 12 (i.e. the inner side step of the ring) is provided with a pair of positioning grooves 12b to bear the ends of the two long guide rods 41, and the radial outer side part (i.e. the outer side step) is provided with an arc-shaped notch 12a to cooperate with the arc-shaped member 81.

[0045] Arc-shaped member 81 is fitted on the arc-shaped notch 12a of the circular ring portion 12, and cooperates with the lens barrel 10 to form a first through-hole 100a and a second through-hole 100b. These two through-holes are used for passing wires, flexible circuit boards, etc. connecting members of the camera lens.

[0046] The cylindrical portion 11 is provided with a wide slit extending through the front and back end faces, which is adjacent to the arc-shaped notch 12a and extends in the axial direction. Thus, the cylindrical portion 11 cooperates with the circular ring portion 12 to form a side wall notch 11c. Both sides of the side wall notch 11c are provided with a boss 111 protruding towards the radial outer side. The outer side surface of the cylindrical portion 11 corresponding to the arc-shaped notch 12a and adjacent to one boss 111 is provided as a planar region 112. The side wall notch 11c, the boss 111 and the planar region 112 are used together for mounting the drive unit 30.

[0047] That is, the side wall of the lens barrel 10 is provided with the side wall notch 11c extending in the axial direction, which cooperates with the drive unit 30.

[0048] Two long guide rods 41 extend in the axial direction and are fixed in the cylindrical portion 11, i.e. the lens barrel 10 is internally provided with two long guide rods 41 extending in the axial direction. The long guide rods 41 are fixedly fitted or integrally connected at one end to the end face of the annular seat 42, and are embedded and fixed at the other end in the positioning groove 12b.

[0049] The lens seat 20 for mounting the movable lens group is located in the lens barrel 10 and is axially slidably fitted on the two long guide rods 41. The lens seat 20 comprises a rigid ring 21 and a lens gasket 22 arranged concentrically. The outer side surface of the rigid ring 21 is provided with a protruding member 211, a U-shaped sliding sleeve 212, a sleeve 213 and a pin rod seat 214. The U-shaped sliding sleeve 212 is diametrically opposite to the sleeve 213 to cooperate with the two long guide rods 41. One end of the pin rod 82 is detachably inserted into the pin rod seat 214 to connect the drive unit 30. The protruding member 211 cooperates with the Hall sensor or the photoelectric sensor mounted on the inner wall of the barrel 10 to define the boundary of the zoom range of the camera lens. When fitting the lens seat 20, a clamp can be used to clamp the protruding member 211.

[0050] Please refer to Figure 5a , Figure 5b The drive unit 30 comprises a U-shaped plate 31, a stepper motor 32 (English abbreviation STM), a lead screw 33, a circular encoder 34, a short guide rod 35, a sheet-like element 36, a transmission member 37 and a nut. The short guide rod 35 is shorter than the long guide rod 41. The above-mentioned nut and the lead screw 33 form a lead screw pair, which is not shown in the drawings.

[0051] Please refer to Figures 1a to 5bThe outer side of one bending section of the Z-shaped plate 31 is equipped with a stepping motor 32, and the outer side of the other bending section is equipped with a circular encoder 34. The middle part of the Z-shaped plate 31, which is wider than the two bending sections, is mounted on the two bosses 111 by a plurality of screws 101. That is, the Z-shaped plate 31 is covered and fixedly mounted on the radial outer side of the side wall notch 11c, and the two bending sections of the Z-shaped plate 31 face the inside of the lens barrel 10.

[0052] The stepping motor 32 is fixedly mounted on the outer side of one bending section of the Z-shaped plate 31, located at the opening of the side wall notch 11c, and embedded in the radial outer side notch of the annular seat 42. The power output end of the stepping motor 32 is located inside the side wall notch 11c, and the opposite end protrudes out of the annular seat 42. That is, a part of the stepping motor 32 is located outside the side wall notch 11c.

[0053] The stepping motor 32 should have a large power-to-volume ratio, and the outer diameter is preferably 5-10 mm and the stepping angle is 5-10 degrees when the working load is 160-170 g.

[0054] The circular encoder 34 is fixedly mounted on the outer side of the other bending section of the Z-shaped plate 31 and abuts against the bottom of the side wall notch 11c. The bottom of the side wall notch 11c is provided with a step matching the circular encoder 34. The lead screw 33 is drivingly connected at one end to the stepping motor 32 and at the other end to the circular encoder 34, and is sleeved with the above-mentioned nut in the threaded area. The above-mentioned nut is not shown in the drawings.

[0055] With the above structure, the circular encoder 34 and the stepping motor 32 are oppositely arranged at the two ends of the lead screw 33 and the outer sides of the bending sections of the Z-shaped plate 31, the structure is symmetrical and easy to assemble; the Z-shaped plate 31 is mounted on the two bosses 111, so that the main body of the driving unit 30 is located between the two bosses 111 and inside the side wall notch 11c, the structure is compact and stable and reliable. Commercially available stepping motor modules, either directly integrated with a gear box and an encoder for large power or using an open-loop control mode for small power, are not suitable for camera lenses.

[0056] Please refer to Figure 6a and Figure 6b The driving member 37 is an integrally formed member including a clamping portion 371 and a pushing portion 372, which is sleeved on the above-mentioned nut through the following U-shaped through slot 37a and is drivingly connected to the lens seat 20 through the pin 82.

[0057] The clamping portion 371 is provided with a U-shaped through slot 37a, and the pushing portion 372 is integrally connected to one side wall of the U-shaped through slot 37a. The U-shaped through slot 37a is straight strip-shaped, and the length direction ends are both U-shaped openings.

[0058] The clamping part 371 corresponding to the bottom of the U-shaped through slot 37a is also in the shape of a Chinese character "fang". Two bending parts 3713 of the part are provided with through holes 37c to match the short guide rod 35.

[0059] The short guide rod 35 passes through the two through holes 37c and is fixedly connected at both ends between the pair of bending parts of the Chinese character "fang" plate 31, thereby serving as a smooth guide rod of the transmission part 37.

[0060] The side wall of the U-shaped through slot 37a away from the transmission part 372 is composed of three clamping jaws that can elastically swing in the radial direction. Among the three clamping jaws, the two clamping jaws 3712 located at the two axial ends are closer to the lead screw 33 than the one clamping jaw 3711 located between the two. The three clamping jaws can abut against different surfaces of the nut, so that the nut is firmly embedded in the U-shaped through slot 37a.

[0061] The actuating part 372 is a cuboid hollow block integrally connected to one side wall of the U-shaped through slot 37a, is provided with a pin rod insertion hole 37b to match the pin rod 82, and is further provided with other blind holes or openings. Therefore, the actuating part 372 is used to drive the lens seat 20 to move axially, can be installed with a magnetic part to match a Hall sensor, and can be installed with a light cursor to match a photoelectric sensor, so as to realize zooming and limiting the boundary of the zooming range.

[0062] Please refer to Figure 7 The sheet-shaped element 36 is a sheet-shaped flat cable or flexible circuit board, which is used to electrically connect the driving unit 30 and an electric control unit 810 of a camera lens. That is, the step motor 31 and the circular encoder 34 are electrically connected to the sheet-shaped element 36, and the sheet-shaped element 36 can be connected to the electric control unit 810.

[0063] The sheet-shaped element 36 includes two branches. One L-shaped branch is led out from the middle of the other branch, the main body of which is attached to the Chinese character "fang" plate 31, and the free end 363 of which is connected to the terminal of the step motor 32. The other branch has a straight strip-shaped main body and is attached to the planar area 112, the free end 362 of which towards the front is T-shaped and is fixed to the planar area 112 by a screw, and the free end 361 towards the back is bent towards the radial inner side after passing through the through hole 100b and bypassing the circular ring body 12. The free end 361 is used to connect the electric control unit 810.

[0064] The circular encoder 34 has a flat cable 341 connected to the terminal thereof, which is electrically connected to the middle of the L-shaped branch of the sheet-shaped element 36 through the flat cable 341, and is used to detect the rotation angle of the lead screw 33.

[0065] The electric control unit 810 can perform step loss compensation on the step motor 32 according to the detection data of the circular encoder 34. The specific situation of the step loss compensation method can be referred to the patent CN106060380A / 2016.

[0066] In summary, the lens zoom mechanism 100 comprises a lens barrel 10, a lens holder 20, a driving unit 30 and a bearing unit 40. In the driving unit 30, the H-shaped plate 31 covers the radial outer side of the side wall notch 11c of the lens barrel 10, the step motor 32 is installed at one end of the H-shaped plate 31, and the round encoder 34 is installed at the other end of the H-shaped plate 31 and located at the bottom of the side wall notch 11c. The lead screw 33 of the driving unit 30 is drivingly connected between the step motor 32 and the round encoder 34 through the two ends, and drives the lens holder 20 through the driving member 37 clamped on the nut. The camera lens using the lens zoom mechanism 100 has a compact structure and can compensate for the step loss of the step motor.

[0067] In other embodiments, the step motor 32 and the round encoder 34 are both installed in the enclosed space of the H-shaped plate 31, or one is installed in the enclosed space and the other is installed outside the enclosed space.

[0068] Embodiment Two

[0069] A step motor driven lens zoom mechanism is disclosed.

[0070] The lens zoom mechanism is improved on the basis of Embodiment One.

[0071] Please refer to Figure 8 The sheet-shaped element 36 of the driving unit 30' is a flexible circuit board, and an inclination sensor 38 is attached thereto. The inclination sensor 38 can be connected to the electronic control unit 810 through the sheet-shaped element 36, and is used to detect the inclination angle of the lead screw 33 (i.e. the angle between the optical axis of the camera lens and the direction of gravity), so that the electronic control unit 810 can perform inclination compensation on the step motor 32.

[0072] The pre-installed program of the electronic control unit 810 includes the following operation logic: according to the functional relationship between the friction of the lead screw-nut and the inclination angle, the step motor power that keeps the zoom speed unchanged at all inclination angles is calculated, so that the zoom speed of the lens zoom mechanism is not affected by the inclination angle.

[0073] In other embodiments, the inclination sensor 38 can be replaced by a gyroscope or other attitude sensor, which can be installed on the lens barrel 10. The inclination sensor 38, the gyroscope and other attitude sensors can also be used in combination.

[0074] Embodiment Three

[0075] A camera lens is disclosed. Please refer again to Figure 7 The camera lens comprises the lens zoom mechanism 100 of Embodiment One and the electronic control unit 810.

[0076] The electric control unit 810 includes a microprocessor 811 (English abbreviation MPU) and a gyroscope 812, and is electrically connected to the step motor 32 and the circular encoder 34, and is used for step loss compensation of the step motor 32 according to the detection data of the circular encoder 34, and is also used for inclination compensation of the step motor 32 according to the detection data of the gyroscope 812. The camera lens zooming is accurate, and the zooming speed is not affected by the orientation.

[0077] In other embodiments, the gyroscope 812 of the electric control unit 810 can be replaced by other attitude sensors.

[0078] In other embodiments, the electric control unit 810 can be combined with an inclination sensor, a gyroscope and other attitude sensors, and the detection data of these sensors are used for camera anti-shake and the above-mentioned inclination compensation.

[0079] Embodiment four

[0080] Another camera lens is disclosed. Please refer to Figure 8 The camera lens includes the lens zooming mechanism of embodiment two, and the electric control unit 810.

[0081] The electric control unit 810 includes a microprocessor 811 and a gyroscope 812, and is electrically connected to the step motor 32, the circular encoder 34 and the inclination sensor 38, and is used for step loss compensation of the step motor 32 according to the detection data of the circular encoder 34, and is also used for inclination compensation of the step motor 32 according to the detection data of the gyroscope 812 and / or the inclination sensor 38. The camera lens zooming is accurate, and the zooming speed is not affected by the orientation.

[0082] The above embodiments, application examples and technical analysis are intended to introduce the technical concept and characteristics of the present application, so that the person skilled in the art can implement the present application, and do not constitute a limitation on the protection scope. Simple modifications and equivalent transformations of the above embodiments are all within the protection scope of the present application.

Claims

1. A stepping motor driven lens zoom mechanism characterized by The lens barrel comprises: a lens barrel body for assembling with other lens barrel bodies into a lens, having two axially extending long guide rods inside, and a side wall having an axially extending side wall notch; a lens holder for mounting a movable lens group, located inside the lens barrel body, and axially slidably assembled on the two long guide rods; and a driving unit drivingly connected to the lens holder; wherein the driving unit comprises: a U-shaped plate covering and fixedly mounted on the radially outer side of the side wall notch; a stepper motor fixedly mounted on the inner side or outer side of a bent section of the U-shaped plate, located at the opening of the side wall notch; a round encoder fixedly mounted on the inner side or outer side of another bent section of the U-shaped plate, located at the bottom of the side wall notch; a lead screw having one end drivingly connected to the stepper motor and the other end drivingly connected to the round encoder, and having a nut threadedly sleeved on the lead screw; and a transmission member sleeved on the nut and drivingly connected to the lens holder; wherein the stepper motor and the round encoder are electrically connected to an electronic control unit for controlling the lens. Further comprising:

2. The lens zoom mechanism according to claim 1, characterized in that a tilt sensor or a gyroscope assembled on the lens barrel body or the driving unit, and electrically connected to the electronic control unit for detecting the angle between the optical axis of the lens and the direction of gravity.

3. The lens zoom mechanism according to claim 1, wherein: the stepper motor and the round encoder are located outside the enclosed space of the U-shaped plate.

4. The lens zoom mechanism according to claim 1, wherein: both sides of the side wall notch are provided with a boss protruding radially outward; the U-shaped plate is mounted on the two bosses.

5. The lens zoom mechanism according to claim 1, wherein: the driving unit further comprises a sheet-like element through which the electronic control unit is electrically connected. the transmission member comprises:

6. The lens zoom mechanism according to claim 1, characterized by a clamping portion provided with a U-shaped through slot for matching the nut; and a pushing portion integrally connected to the clamping portion and drivingly connected to the lens holder.

7. The lens zoom mechanism according to claim 6, wherein: one side wall of the U-shaped through slot is configured as a plurality of clamping jaws axially distributed and radially elastically swingable; two clamping jaws located at the two axial ends are closer to the lead screw than the other clamping jaws located between the two. The lens zoom mechanism according to claim 1, 3, 4, 5, 6 or 7; and 8. A camera lens characterized by the electronic control unit electrically connected to the stepper motor and the round encoder respectively, comprising a tilt sensor or a gyroscope, and capable of calculating the angle between the optical axis of the lens and the direction of gravity. The lens zoom mechanism according to claim 2; and the electronic control unit electrically connected to the stepper motor and the round encoder respectively, and further electrically connected to the tilt sensor or the gyroscope. ​ 9. A camera lens characterized by ​ ​ ​ ​

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