TWI698671B - Lens autofocus driving device - Google Patents

Abstract

A lens auto-focusing driving device is provided in an outer frame with a lens frame with a guide pin, and the lens frame is driven to move relative to the outer frame with the guide pin as the center by an actuator that can be energized and thermally deformed; wherein , An elastic element is provided on a corner protrusion of the frame adjacent to the guide pin, and the frame is moved relative to the outer frame by the elastic element to apply elastic force to the original position; the outer frame is adjacent to the The position of the guide pin is provided with a restriction element having at least one pair of guide posts, and a plurality of balls are arranged around the space enclosed by the guide posts and the guide pin, so that the guide pin and the guide posts can be contacted rollingly, so that The movement of the frame relative to the outer frame is smoother.

Description

Lens autofocus driving device

The invention relates to a lens automatic focusing drive device, in particular to a smoother structure during automatic focusing.

In a photographing device such as a camera with a lens, it is necessary to move the lens to change the higher harmonic components (focus) of the image when performing a photographing operation, and a function to perform autofocus is provided.

The focus of the conventional photographing device is completed by an automatic drive module. For example, a shape memory alloy (SMA) wire deformed by temperature changes is used in the drive module to drive the frame relative to The outer frame is moved in a predetermined direction to focus, and the elastic element is used to move the lens frame toward the original position; that is, the lens module with the lens module is installed through the action of the drive module with the shape memory alloy wire and the elastic element The frame can be moved back and forth relative to the outer frame to automatically focus.

The memory alloy wire has the characteristics of being deformed to shorten the length after being heated by the current, and naturally stretch to the original length when the current is not applied, and the elongation can be adjusted when the current is adjusted to adjust the heat. It is a known technology that the shape memory alloy wire is heated by the resistance generated when it is energized; therefore, by controlling the energization of the shape memory alloy wire while monitoring the resistance of the shape memory alloy wire, the lens frame can be controlled to move to the focus position.

The autofocus device disclosed in the Republic of China Patent No. 201435466 includes a lens frame (LC) slidably housed in a fixed outer frame (HF) in a reciprocating motion, and the reciprocating motion is composed of at least one V-shaped shape memory alloy The actuator of the wire (SW) is provided, the frame (LC) is provided with embedded in the corner protrusion (CP) and its ends are accommodated in the outer frame (HF) and the bottom plate (BP), respectively. The guide pin (GP) in the bushing hole (BH).

The object of the present invention is to provide a structure that enables the lens autofocus driving device to autofocus more smoothly and has a simpler structure.

The lens auto-focus driving device provided by the present invention may include: an outer frame with an accommodating space; a lens frame on which a corner protrusion can be arranged on the outer side, and a guide pin is arranged on the corner protrusion, and the lens frame is arranged on the The accommodating space of the outer frame allows the frame to move relative to the outer frame along the axial direction of the optical axis; the actuator includes a shape memory alloy wire that connects the outer frame and the outer frame The shape memory alloy wire is energized to produce thermal deformation to drive the frame to move relative to the outer frame; an elastic element is arranged on the corner protrusion adjacent to the guide pin, when the frame is subjected to the After the actuator is driven and displaced, the elastic element stores the elastic force. When the actuator releases the drive of the frame, the elastic element applies the stored elastic force to the frame to move the frame toward the original position A restriction element having at least a pair of guide posts, the restriction element is arranged on the outer frame and adjacent to the position of the guide pin; and a plurality of balls are arranged around the space enclosed by the guide posts and the guide pin, And it is in rolling contact with the surface of the guide pin and the guide post. When the frame is driven by the shape memory alloy wire to move axially relative to the outer frame, the balls are relatively rolled between the guide pin and the guide post, so that the rotation of the guide pin is smoother and more stable, and the overall structure is more smooth. concise.

Preferably, the present invention may further include a bottom plate which is overlappedly arranged on the outer bottom surface of the outer frame, so that the balls arranged in the space enclosed by the guide posts and the guide pins are restricted to prevent the balls from falling off from below The space.

In one embodiment, the present invention can provide a fitting hole in the corner protrusion of the frame, and fit and fix the guide pin in the fitting hole so that the opposite ends of the guide pin extend out of the corner projection.

In another embodiment, the present invention can fix the guide pin on the corner protrusion of the frame by welding.

Preferably, the present invention can be provided with a concave portion extending along the axial direction on the outer diameter of the guide pins, and the ball is restricted to the position of the concave portion, so that the ball can be stably located between the guide pin and the guide pin. Scroll relative to each other.

In an embodiment, the limiting element may be fixed to the outer frame by at least one fixing element.

In another embodiment, the limiting element may be welded and fixed to the outer frame.

In another embodiment, a connecting plate may be arranged between the upper ends of the pair of guide posts of the restricting element, so that the balls arranged in the space enclosed by the guide posts and the guide pins are restricted, so as to prevent the balls from being moved from above. Get out of the space.

Preferably, in the present invention, a clamping portion may be provided at two different positions of the outer frame; the corner protrusion is provided with a step portion; and the shape memory alloy wire is a V-shaped wire, and the shape memory alloy wire The two ends of the V shape are respectively fitted into the two clamping parts, and the inside of the tip between the two ends of the V shape is fitted to the step part, thereby completing the connection of the frame to the outer frame through the shape memory alloy wire It can also drive the frame.

The present invention uses the aforementioned combination structure of the guide pin, the guide pin and the ball to make the guide pin more stable by being held by the ball when the frame moves, and the ball, the guide pin and the guide pin roll relatively , Causing them to produce rolling friction between each other and move smoothly.

The following is a more detailed description of the implementation of the present invention in conjunction with the drawings and component symbols, so that those who are familiar with the art can implement it after studying this manual.

1 is a perspective schematic diagram showing the overall appearance structure of the lens autofocus driving device of the present invention; FIG. 2 is a top plan schematic diagram showing the overall appearance structure of the lens autofocus driving device of the present invention; FIG. 3 is a schematic diagram showing the overall appearance structure of the lens autofocus driving device of the present invention Fig. 4 is a sectional view along the line IV-IV of Fig. 2; Fig. 5 is a sectional view along the line Ⅴ-Ⅴ of Fig. 2; Fig. 6 is a view showing the auto-focus driving of the lens of the present invention The guide post of the device is fixed to the outer frame by a fixing element, and the guide pin is embedded in the corner projection; FIG. 7 shows the guide post of the lens auto-focus driving device of the present invention fixed to the outer frame by welding. And the guide pin is embedded in the three-dimensional schematic diagram of the embodiment of the corner protrusion; FIG. 8 shows that the guide post of the lens auto-focus driving device of the present invention is fixed to the outer frame by the fixing element, and the guide pin is fixed to the corner convex by welding Fig. 9 is a perspective view showing an embodiment in which the guide post of the lens autofocus driving device of the present invention is fixed to the outer frame by welding, and the guide pin is also fixed on the corner protrusion by welding.

As shown in FIGS. 1 to 5, the preferred embodiment of the lens autofocus driving device provided by the present invention may include: an outer frame 1, a lens frame 2, a bottom plate 3, an actuator 4, and a shape memory alloy Wire 5 (Shape memory alloy, SMA), at least one spring 6, a restricting element 7, a plurality of balls 8 and a guide pin 9.

Among them, as shown in Figure 3, the outer frame 1 preferably forms a rectangular body, and is recessed from top to bottom with an accommodating space 11, the bottom of the accommodating space 11 is formed with a central hole 12, in one of the outer frame 1 The outer frame 1 on both sides of the corner 13 is provided with a first positioning hole 14 and a second positioning hole 15. The bottom plate 3 is provided on the outer bottom surface of the outer frame 1. For example, the bottom plate 3 can be formed to substantially correspond to the contour shape of the bottom surface of the outer frame 1, and a through hole 30 corresponding to the central hole 12 of the outer frame 1 is formed on the bottom plate 3. And the positioning pillars 31 and the positioning holes 32 respectively corresponding to the first positioning holes 14 and the second positioning holes 15, whereby the positioning pillars 31 can be passed through the first positioning holes 14 of the outer frame 1 from bottom to top for positioning, The bottom plate 3 is locked to the outer frame 1 with fixing elements such as screws. In addition, the first positioning hole 14 serves as a channel for installing the ball 8 at the same time, and the positioning post 31 is used to pass through the first positioning hole 14 to prevent the ball 8 from falling down.

The frame 2 is a component used to install a lens module (not shown in the figure). The frame 2 is basically formed with a lens mounting hole 20, and the entire frame 2 can be installed in the housing space 11 of the outer frame 1. Inside, so that the frame 2 can move relative to the outer frame 1 along the axial direction of the optical axis in the accommodating space 11 of the outer frame 1; therefore, the frame 2 preferably has its lens mounting hole 20 corresponding to the outer frame 1之中心孔12。 The center hole 12. In addition, a corner protrusion 21 is provided on the outer side of the frame 2. The corner protrusion 21 has a fitting hole 211 formed to penetrate up and down. The corner protrusion 21 next to the fitting hole 211 is formed with an upwardly protruding protrusion. 212; Furthermore, the outer surface of the corner protrusion 21 is formed with a step portion 213. More specifically, the step portion 213 is tied to the outer surface of the corner protrusion 21 to form a gap, so that the bottom of the corner protrusion 21 is opposite to The top is recessed in the radial direction.

The guide pin 9 is a cylindrical body, the axial length of which is greater than the axial length of the fitting hole 211, and a flange 91 is formed at an appropriate position. The outer diameter of the guide pin 9 can basically be inserted into the corner protrusion 21. The inner diameter of the engaging hole 211 produces interference fit, or the outer diameter of the guide pin 9 and the inner diameter of the fitting hole 211 are adhered and fixed with an adhesive, and after the guide pin 9 is installed in the fitting hole 211, the flange 91 is used to abut against the insert The outer edge of the lower end of the engaging hole 211 is positioned, and the opposite ends of the guide pin 9 are respectively extended from the upper and lower surfaces of the angular protrusion 21, whereby when the frame 2 is set in the accommodating space 11 of the outer frame 1, Later, in the initial state where the frame 2 is not driven by external force, the lower end of the guide pin 9 can be made to abut the corner 13 position on the outer frame 1, and the frame 2 is guided by the guide pin 9 and the restricting element 7 and The structure in which the balls 8 are in contact with each other and driven by the actuator 4 can make the frame 2 and the guide pin 9 move relative to the outer frame 1 at the same time.

The actuator 4 may preferably include a first fixing member 41A, a second fixing member 41B, and a shape memory alloy wire 5. The shape memory alloy wire 5 can be deformed by being heated by an electric current. Shorten the length, naturally stretch to the original length when no current is passed through, and adjust the amount of elongation when the amount of current is adjusted to adjust the heat; the shape memory alloy wire 5 is known to be heated by the resistance generated when the current is turned on Technology, so a more detailed description is omitted in this article. The first fixing member 41A and the second fixing member 41B can be formed into a predetermined shape by using metal plates, so as to be fixed to the outer frame 1 with fixing elements such as screws or glue; specifically, the first fixing is The member 41A and the second fixing member 41B are respectively locked on opposite sides of the corner of the outer frame 1 where the thimble 9 is installed; the first fixing member 41A and the second fixing member 41B are respectively formed with a hook shape夹合部411。 Clip joint 411. The shape memory alloy wire 5 is pre-formed into a V shape. After the first fixing member 41A and the second fixing member 41B are fixed to the outer frame 1, the two ends of the V-shaped shape memory alloy wire 5 are clamped to the first A fixing part 41A and a clamping part 411 on the second fixing part 41B, and the inner side of the V-shaped tip between the two ends of the shape memory alloy wire 5 is placed on the step part 213 of the corner protrusion 21 of the frame 2, This completes the connection of the shape memory alloy wire 5 to the outer frame 1 and the frame 2. The shape memory alloy wire 5 is further electrically connected to a power device, so that the shape memory alloy wire 5 is energized and generates thermal deformation to drive the frame 2 to move relative to the outer frame 1. Specifically, the first fixing member 41A and the The two fixing parts 41B are also electrically connected to the flexible circuit board 16 provided on the motor. The flexible circuit board 16 is provided with a driving chip and a Hall sensing element 161. The driving chip may be equipped with a Hall sensing element 161 or The two are arranged independently and electrically connected. The Hall sensor element 161 is used to sense the position of the magnet 22 arranged on the frame 2, and the drive chip determines whether to match the shape according to the change in the magnetic field of the Hall sensor element 161 The shape memory alloy wire 5 is energized and heated to deform or restore the shape memory alloy wire 5 to its original shape. On the other hand, the present invention also sleeves an elastic element 6, such as a compression spring, on the boss 212 of the frame 2, and connects one end of the elastic element 6 to another object (not shown in the figure) other than the frame 2. In this way, when the frame 2 is driven and displaced by the shape memory alloy wire 5, the elastic element 6 is deformed to store the elastic force. When the shape memory alloy wire 5 releases the driving of the frame 2, the elastic element 6 is used to apply to the frame 2 The stored elastic force is used to move the frame 2 toward the original position.

The present invention also includes a restriction element 7 in the shape of an ㄇ. The restriction element 7 includes a pair of upright and parallel guide posts 70. The upper ends of the two guide posts 70 are connected by a cross bar 76. The pair of guide posts 70 It is used to be arranged on the outer frame 1 and adjacent to the position of the guide pin 9; specifically, the upper and lower ends of each guide post 70 are respectively formed with an axially protruding upper protrusion 72 and a lower protrusion 71, the lower protrusion The post 71 corresponds to the second positioning hole 15 of the outer frame 1 and the positioning hole 32 of the bottom plate 3, so that the limiting element 7 is positioned by passing the lower protrusion 71 through the second positioning hole 15 and the positioning hole 32 at the same time, Then use a fixing element to fix the restricting element 7 at this position; for example, glue can be used to inject the concave hole provided at the end of the lower protrusion 71 from bottom to top to fix the restricting element 7 so that the two guide posts 70 and An enclosed space is formed between a guide pin 9 (as shown in Figs. 5 and 6). When the limiting element 7 is fixed, a connecting plate 74 with a larger width can be provided on the cross bar 76 between the upper ends of the two guide posts 70, and the connecting plate 74 blocks the surrounding between the two guide posts 70 More specifically, the connecting plate 74 can be provided with slots 741 near both ends, so that when the connecting plate 74 is placed on the cross bar 76, the upper protrusion 72 can pass through the slot 741, and then Then, a fixing element such as glue is used to adhere to the upper protrusion 72 to fix the connecting plate 74 above the restricting element 7.

Furthermore, in order to make the mirror frame 2 rotate more smoothly relative to the outer frame 1, the present invention also arranges a plurality of balls 8 around the space enclosed by the guide posts 70 and the guide pins 9, and the balls 8 and the guide The surfaces of the needle 9 and the guide posts 70 are in rolling contact (as shown in FIGS. 4 and 5); preferably, the present invention can provide a recess 73 extending in the axial direction on the outer diameter of the guide posts 70 (As shown in Figure 5), the ball 8 can be restricted to the position of the recess 73 by the recess 73 and the connecting plate 74, so that the ball 8 can stably face each other between the guide pin 9 and the recess 73 of the guide post 70 scroll. When the frame 2 is driven by the shape memory alloy wire 5 to move relative to the outer frame 1, the balls 8 are driven to roll relatively between the guide pin 9 and the guide post 70, that is, the frame is supported by the rolling support of the balls 8 2 The movement relative to the outer frame 1 is smoother and more stable, and the overall structure is simpler. In the present invention, a plurality of balls 8 are preferably arranged above the corner protrusion 21 and below the flange 91, so that more balls 8 are supported around the guide pin 9 so that the guide pin 9 can move more smoothly . In more detail, when installing the ball 8 above the corner protrusion 21, the connecting plate 74 is first removed, and then the ball 8 is inserted from top to bottom along the recess 73 of the guide post 70, and then the connecting plate 74 Place on the cross bar 76, let the upper protrusion 72 pass through the slot 741, and then lock the upper protrusion 72 with fixing elements such as screws to fix the connecting plate 74 above the restricting element 7 to prevent the balls 8 from being removed Depart from above. When installing the ball 8 under the flange 91, first remove the bottom plate 3, and then place the ball 8 from bottom to top through the first positioning hole 14 along the recess 73 of the guide post 70, and then overlap the bottom plate 3 It is installed at the bottom of the outer frame 1, and the positioning post 31 passes through the first positioning hole 14 to prevent the ball 8 from falling downward.

In addition to assembling the guide pin 9 to the fitting hole 211 of the corner protrusion 21 and fixing the restricting element 7 to the outer frame 1 (as shown in FIG. 6) by the fixing element, the present invention can also be used in another In the embodiment, the restriction elements are welded and fixed to the outer frame 1, that is, a welding portion 74 is formed on the periphery where the guide post 70 contacts the outer frame 1 (as shown in FIG. 7). Alternatively, in another embodiment, the guide pin 9 is integrally formed on the corner protrusion 21 of the frame 2, that is, a welding portion 92 is formed on the periphery where the guide pin 9 contacts the corner protrusion 21 (as shown in FIG. Show). Alternatively, in another embodiment, the guide posts 70 are welded and fixed to the outer frame 1, and the guide pins 9 are integrally formed on the corner protrusions 21 of the frame 2, that is, the guide posts 70 and the outer frame A welded portion 74 is formed on the periphery where the frame 1 contacts, and a welded portion 92 is formed on the periphery where the guide pin 9 contacts the corner protrusion 21 (as shown in FIG. 9).

The present invention uses the aforementioned combination structure of the guide pin, the guide pin and the ball to make the guide pin more stable by being held by the ball when the frame moves, and the ball, the guide pin and the guide pin roll relatively , Causing them to produce rolling friction between each other and rotate smoothly.

It can be seen from the above embodiments that the lens auto-focus driving device provided by this creation does have industrial utility value, but the above description is only an illustration of the preferred embodiment of this creation. Those who are familiar with this technique can follow the above description For other various improvements, these changes still belong to the spirit of this creation and the scope of the patent application defined below.

1: Outer frame

11: Housing space

12: Center hole

13: corner

14: The first positioning hole

15: The second positioning hole

16: Flexible circuit board

161: driver chip

2: Frame

20: Lens mounting hole

21: corner raised

211: Fitting hole

212: convex column

213: Class Department

22: Magnet

3: bottom plate

30: Through hole

31: positioning column

32: positioning hole

4: Actuator

41A: The first fixing part

41B: second fixing part

411: Clamping part

5: Shape memory alloy wire (SMA)

6: Elastic element

7: Restricted components

70: guide post

71: Lower protrusion

72: Upper bulge

73: recess

74: connecting plate

741: Slot

75: Welding Department

76: Crossbar

8: Ball

9: Guide pin

91: flange

92: Welding Department

FIG. 1 is a three-dimensional schematic diagram showing the overall appearance structure of the lens auto-focus driving device of the present invention; 2 is a schematic top plan view showing the overall appearance structure of the lens auto-focus driving device of the present invention; 3 is a perspective exploded view showing the combination of main components of the lens autofocus driving device of the present invention; Figure 4 is a cross-sectional view taken along line Ⅳ-Ⅳ of Figure 2; Figure 5 is a cross-sectional view along the line Ⅴ-Ⅴ of Figure 2; 6 is a perspective view showing an embodiment in which the guide post of the lens auto-focus driving device of the present invention is fixed to the outer frame by a fixing element, and the guide pin is embedded in the corner protrusion; 7 is a perspective view showing an embodiment in which the guide post of the lens auto-focus driving device of the present invention is fixed to the outer frame by welding, and the guide pin is embedded in the corner protrusion; 8 is a perspective view showing an embodiment in which the guide post of the lens auto-focus driving device of the present invention is fixed to the outer frame by a fixing element, and the guide pin is fixed to the corner protrusion by welding; and 9 is a perspective view showing an embodiment in which the guide post of the lens auto-focus driving device of the present invention is fixed to the outer frame by welding, and the guide pin is also fixed to the corner protrusion by welding.

1: Outer frame

2: Frame

21: corner raised

213: Class Department

22: Magnet

411: Clamping part

5: Shape memory alloy wire (SMA)

6: Elastic element

7: Restricted components

70: guide post

8: Ball

9: Guide pin

Claims (9)

A lens auto-focus driving device includes: an outer frame with an accommodating space; a lens frame with a corner protrusion on the outer side, the corner protrusion is provided with a guide pin, the lens frame is arranged on the outer frame In the accommodating space, the frame can move relative to the outer frame; the actuator includes a shape memory alloy wire, the shape memory alloy wire connects the outer frame and the frame, the shape memory alloy wire is energized to produce Thermally deformed to drive the lens frame to move relative to the outer frame; it is characterized in that it further comprises: an elastic element arranged on the corner protrusion adjacent to the guide pin, when the lens frame is driven by the actuator to shift Then the elastic element is made to store the elastic force. When the actuator releases the drive of the frame, the elastic element applies the stored elastic force to the frame to move the frame in the original position; a limiting element , Having at least a pair of guide posts, the restricting element is arranged on the outer frame and adjacent to the position of the guide pin; and a plurality of balls are arranged around a space surrounded by the guide posts and the guide pin, and are connected to the The surface of the guide pin and the guide post are in rolling contact, wherein the shape memory alloy wire has a first fixing part and a second fixing part, and the first fixing part and the second fixing part are electrically connected to the A flexible circuit board of a motor, the flexible circuit board is provided with a driving chip and a Hall sensing element, the driving chip is electrically connected to the Hall sensing element, and the Hall sensing element is arranged on the The position of a magnet of the frame allows the drive chip to determine whether the shape memory alloy wire is energized and heated. For the lens auto-focus driving device described in the first item of the patent application, the outer diameter of the guide posts is provided with a recess extending along the axial direction, and the balls are restricted at the position of the recess. For example, the lens auto-focus driving device described in the first item of the scope of patent application further includes a bottom plate overlappingly arranged on the outer bottom surface of the outer frame to restrict the balls from being separated from the guide posts and the guide The space surrounded by the needle. The lens auto-focus driving device described in item 3 of the scope of patent application, wherein the corner protrusion is provided with a fitting hole, and the guide pin is fitted and fixed in the fitting hole so that the guide pin extends at opposite ends The corner is raised. According to the lens auto-focus driving device described in item 3 of the scope of patent application, the guide pin and the corner protrusion are fixed to each other by welding. According to the lens auto-focus driving device described in item 1 of the scope of patent application, the limiting element is fixed on the outer frame by at least one fixing element. In the lens auto-focus driving device described in item 1 of the scope of patent application, the limiting element is welded and fixed to the outer frame. For the lens auto-focus driving device described in item 1 of the scope of patent application, wherein the upper ends of the pair of guide posts of the restricting element are connected by a connecting plate to restrict the balls from being separated from the guide posts from above And the space enclosed by the guide pin. For the lens auto-focus driving device described in item 1 of the scope of patent application, wherein two different positions of the outer frame are respectively provided with a clamping part; the corner protrusion is provided with a step part; and the shape memory alloy wire is V Shaped wire, the V-shaped two ends of the shape memory alloy wire are respectively fitted into the two clamping parts, and the inner side of the tip part between the two ends of the V-shape is fitted to the step part.

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