KR101032195B1 - Lens feeder - Google Patents

Abstract

According to an aspect of the present invention, there is provided a lens transporting apparatus including: a housing having a guide part formed at an angle to have two contacts with a ball member in a receiving space; A piezoelectric unit mounted to the housing to be located in the accommodation space; A lens barrel accommodated in the accommodation space and moved in the optical axis direction by driving the piezoelectric unit; Protruded from the outer surface of the lens barrel in a shape corresponding to the guide portion to accommodate a portion of the ball member, arranged at regular intervals along the optical axis direction and extending in a direction perpendicular to the optical axis direction A mounting portion formed of a plurality of plates and having a groove in which the ball member is mounted between the plates; And a ball member mounted to the groove to make a rolling contact with the guide part.

Description

Lens transfer device {LENS DRIVING DEVICE FOR AUTO FOCUS}

The present invention relates to a lens transfer apparatus, and more particularly, to a lens transfer apparatus mounted on an electronic device to enable autofocus when capturing an image in a camera module.

In general, in addition to the main functions, additional functions are added to personal portable devices such as electronic devices, mobile phones, PDAs, etc. These days, many electronic devices have gained popularity among consumers by adding camera functions. Therefore, the market of the camera module mounted therein is also expanding.

In response to the demands of the market, camera modules are evolving from simple functions that can only be fixed focus to additional functions such as auto focus, optical zoom, and optical image stabilization (OIS).

In particular, in order to implement additional functions such as auto focus, optical zoom, and optical image stabilization (OIS), a lens transfer device equipped with an actuator capable of transferring a lens is essential.

Lens transfer devices using actuators, which are widely applied to camera modules, are classified into VCM (Voice Coil Motor), Piezo and Step Motor.

The lens conveying apparatus having such a method can be selectively applied according to the characteristics of the electronic device. For example, the step motor method is mainly employed in general DSC, and the VCM and piezo methods are generally applied to devices that are miniaturized.

Piezo-type lens transfer devices are frequently used in personal portable devices, which have recently been miniaturized, and the lens transfer devices of the above-described methods have high unit costs and high unit costs to realize such structures. There is a drawback to very high.

Therefore, the structure of the piezoelectric lens transfer apparatus applied to a personal portable terminal requires a technique capable of precise transfer to the lens barrel while lowering the cost of the parts.

The present invention relates to a lens transfer device in which a ball member is directly engaged to a mounting portion formed in a lens barrel.

According to an aspect of the present invention, there is provided a lens transporting apparatus including: a housing having a guide part formed at an angle to have two contacts with a ball member in a receiving space; A piezoelectric unit mounted to the housing to be located in the accommodation space; A lens barrel accommodated in the accommodation space and moved in the optical axis direction by driving the piezoelectric unit; Protruded from the outer surface of the lens barrel in a shape corresponding to the guide portion to accommodate a portion of the ball member, arranged at regular intervals along the optical axis direction and extending in a direction perpendicular to the optical axis direction A mounting portion formed of a plurality of plates and having a groove in which the ball member is mounted between the plates; And a ball member mounted to the groove to make a rolling contact with the guide part.

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The lens barrel may include a friction part in contact with the piezoelectric unit and a mounting groove in which the friction part is seated.

In addition, the mounting groove and the mounting portion is characterized in that formed in the lens barrel to face each other.

In addition, the housing may include an exposure hole formed to expose the piezoelectric unit to the accommodation space.

The piezoelectric unit may include a piezoelectric element mounted on a substrate and exposed to the accommodation space, and an elastic member for closely contacting the piezoelectric element to the lens barrel.

The piezoelectric unit may further include a nonconductive flexible member interposed between the piezoelectric element and the elastic member.

In the lens conveying apparatus of the present invention, when the lens barrel is moved along the guide portion of the housing by the piezoelectric unit, the ball member is directly coupled to the mounting portion formed in the lens barrel, so that a separate part for fixing the ball member is not required. Can be lowered.

1 is an exploded perspective view of a lens transport apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the lens transport apparatus according to the exemplary embodiment of the present invention includes a housing 110, a piezoelectric unit 120, a substrate 130, a lens barrel 150, and a ball member 160.

Here, the lens transport apparatus may refer to a camera module further including an image sensor and a substrate for converting an image formed in the lens into an electrical signal.

The housing 110 has a structure in which an upper end and a lower end are open, and includes a receiving space 112 that can accommodate the lens barrel 150.

The accommodation space 112 is formed in a shape corresponding to the outer shape of the lens barrel 150, and is in close contact with the lens barrel 150 to fix the position of the lens barrel 150.

An exposed groove (not shown) is formed on one surface of the housing 110 to expose the piezoelectric unit 120 mounted on the substrate 130 to the accommodation space 112, and the position sensor 132 is formed on the other surface of the housing 110. Is provided to detect the position of the lens barrel 150. At this time, the housing 110 is preferably manufactured by injection molding to have such a shape.

Inside the housing 110 is formed a guide portion 114 continuously provided in the vertical direction.

The guide part 114 is provided in a shape capable of accommodating the mounting part 152 of the lens barrel 150, and is preferably integrally formed inside the housing 110. However, the guide part may be implemented by attaching a separate guide means to the housing according to the designer's intention.

The piezoelectric unit 120 is positioned to be exposed to the accommodation space 112 of the housing 110 and is in direct contact with the friction part 154 formed on one side of the lens barrel 150.

The piezoelectric unit 120 includes a piezoelectric element 121, a friction material 122, a flexible member 142, and an elastic member 144.

The piezoelectric element 121 is directly mounted to the substrate 130 by using a surface mounting technique, and converts an electrical signal into a mechanical signal by a piezoelectric body, and the friction portion 154 of the lens barrel 150 and the piezoelectric element ( The friction material 122 mounted on 121 is directly rubbed against each other. Therefore, the mechanical signal of the piezoelectric element 121 The friction part 154 of the lens barrel 150 is pushed in the vertical direction to move the lens barrel 150 up and down together.

The flexible member 142 may be interposed between the piezoelectric element 121 and the elastic member 144, and the flexible member 142 may be configured to omit the flexible member.

Conventionally, the flexible member 142 is disposed between the piezoelectric element 121 and the substrate 130 to be in direct contact with the piezoelectric element 121. Therefore, the flexible member 142 must use a conductive rubber so that the electrical signal of the substrate 130 can be transmitted to the piezoelectric element.

However, in the present embodiment, since the piezoelectric element 121 is directly mounted on the substrate 130, the flexible member of the conductive material is not necessary. Accordingly, it is possible to use a general rubber material other than the conductive rubber material or to omit the flexible member, thereby lowering the unit cost of the product.

The elastic member 144 functions to contact the piezoelectric element 121 and the flexible member 142 is to be able to deliver the mechanical power to the friction portion 154 of the lens barrel 150 effectively.

In addition, both ends of the elastic member 144 are fixed to the housing 110 to fix the position of the piezoelectric element 121 to the accommodation space of the housing 110.

At this time, protruding portions are formed at the upper and lower ends of the housing 110, and both ends of the elastic member 144 are fitted to the protruding portions, and the position thereof is fixed to the housing 110.

The substrate 130 refers to a flexible substrate, and is preferably mounted outside the housing 110.

The substrate 130 mounts the position sensor 132, and the mounted position sensor 132 senses the position of the lens barrel 150 through an opening formed at the outside of the housing 110.

However, in this embodiment, the ball member 160 is in close contact with the lens barrel 150 and rotates along the guide portion 114 of the housing 110 to stably transport the lens barrel 150. Therefore, since the feeding speed of the lens barrel 150 is constant, the position sensor 132 may be omitted, and as the position sensor is omitted, the unit cost of the component implementing the piezoelectric unit structure may be reduced.

In addition, the piezoelectric element 121 is directly mounted on the substrate 130 by using a surface mounting technique. In this case, the substrate 130 on which the piezoelectric unit 120 and the position sensor 132 are mounted may be bent to surround the housing 110 and mounted outside the housing 110.

FIG. 2 is a perspective view illustrating a lens barrel of a lens transfer apparatus according to an exemplary embodiment of the present invention, and FIG. 3 is a view illustrating a case in which a housing and a lens barrel are coupled to the lens transfer apparatus of FIG. 2.

Referring to FIG. 2, the lens barrel 150 may be assembled to accommodate at least one or more lenses therein and to be accommodated in the accommodation space of the housing 110.

In this case, the accommodating space of the housing 110 is exposed through the piezoelectric unit 120 and the opening, and the friction part 154 of the lens barrel 150 and the friction material 122 of the piezoelectric unit 120 are in close contact with each other.

Therefore, the mechanical signal generated in the piezoelectric unit 120 by the electrical signal is rubbed with the friction portion of the lens barrel 150, this friction force causes the lens barrel 150 to guide the 114 of the housing 110 Move up and down along).

One side of the lens barrel 150 is provided with a mounting portion 152 for binding with the ball member 160.

The mounting portion 152 may be provided integrally when the protruding portion protruding outward from the circular lens barrel 150 is mounted to the guide portion 114 and the lens barrel 150 is formed by injection molding.

The mounting portion 152 is composed of a plurality of plates 156 extending in a direction perpendicular to the optical axis as shown in FIG. The plate 156 is disposed at regular intervals in the optical axis direction. A plurality of grooves 158 into which the ball member 160 may be inserted are provided between the plates 156 disposed as described above. The ball member 160 is inserted into each groove 158. The shape of the groove 158 may be changed and applied differently from this embodiment.

At this time, the ball member 160 is rotatably mounted to the mounting portion 152, and rotates when the lens barrel 150 moves up and down while being in close contact with the guide portion 114, thereby reducing the friction force that may occur in the guide portion 114. Will be reduced.

Therefore, the lens barrel 150 smoothly moves by the rotation of the ball member 160 along the guide portion 114.

In addition, a mounting groove is formed in the lens barrel 150 to fix and fix the friction portion 154, and the mounting groove and the mounting portion 152 are formed in the lens barrel 150 to be located in opposite directions.

Referring to FIG. 3, the lens barrel 150 in which the ball member 160 is rotatably mounted is assembled to the guide part 114. The ball member 160 and the guide part 114 are inserted to closely contact each other. .

Therefore, the guide portion 114 and the lens barrel 150 are in close contact with each other, while the ball member 160 is positioned therebetween to reduce friction while rotating when the lens barrel 150 moves up and down, thereby reducing the lens barrel. Allow 150 to move stably without shaking.

Conventionally, a method of manufacturing a separate structure in which the ball member 160 is mounted, mounting the ball member 160 in a separate structure, and assembling the structure to the lens barrel 150 is used.

Therefore, when the structure on which the ball member 160 is mounted is mounted on the lens barrel 150, the structure and the lens barrel 150 may not be in close contact with each other, and the lens barrel 150 may move upward and downward. The movement speed of the lens barrel is not constant due to problems such as shaking or the position of the structure not fixed to the housing.

However, in this embodiment, the lens barrel 150 and the guide portion 114 are in close contact with each other, and the ball member 160 rotates therebetween to move the lens barrel 150, thereby moving more stably while maintaining a constant moving speed. I can keep it.

Therefore, there is no need to have a structure for mounting the ball member 160 to the lens barrel 150, thereby reducing the cost. In addition, since the lens barrel 150 moves at a constant moving speed, it is possible to reduce the cost of parts by omitting the position sensor.

4 is a partial perspective view illustrating a piezoelectric unit in a lens transport apparatus according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the piezoelectric unit 120 is directly mounted on the substrate 130 by using a surface mounting technique. The substrate 130 may be provided with a separate space for mounting the piezoelectric unit 120. Do.

Therefore, after the component is mounted on the substrate 130, the substrate 130 may be bent to surround the outer side of the housing 110 so that the piezoelectric unit 120 may be exposed to the accommodation space of the housing.

5 is a lens transport apparatus according to another embodiment of the present invention It is a figure for demonstrating an elastic member among them.

Referring to FIG. 5, the elastic member 240 is positioned to correspond to the substrate 230 on which the piezoelectric element 220 is mounted, and both ends thereof are fixed to the housing.

The elastic member 240 has a bow-shaped shape so that the center thereof is in close contact with the substrate 230 and has a structure that absorbs the shock generated by the piezoelectric element 220 by such a structure.

Therefore, the piezoelectric element 220 is fixed to the housing 210 by the elastic member 240 and functions to closely contact the lens barrel. Therefore, since there is no configuration for the conductive rubber in the piezoelectric unit, the cost of the part for the piezoelectric unit structure can be reduced.

1 is an exploded perspective view of a lens transport apparatus according to an embodiment of the present invention.

2 is a perspective view illustrating a lens barrel of a lens transport apparatus according to an exemplary embodiment of the present invention.

3 is a view for explaining that the housing and the lens barrel in the lens transfer device of FIG.

FIG. 4 is a partial perspective view illustrating a piezoelectric unit device among lens transport apparatuses according to an exemplary embodiment of the present invention.

5 is a view for explaining an elastic member of a lens transport apparatus according to another exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110 ... housing 120 ... piezoelectric unit

130 .... Substrate 150 .... Lens Barrel

Claims (7)

A housing having a guide part formed at an angle to have two contacts with the ball member in the accommodation space; A piezoelectric unit mounted to the housing to be located in the accommodation space; A lens barrel accommodated in the accommodation space and moved in the optical axis direction by driving the piezoelectric unit; Protruded from the outer surface of the lens barrel in a shape corresponding to the guide portion to accommodate a portion of the ball member, arranged at regular intervals along the optical axis direction and extending in a direction perpendicular to the optical axis direction A mounting portion formed of a plurality of plates and having a groove in which the ball member is mounted between the plates; And A ball member mounted to the groove to make a rolling contact with the guide part; Lens transfer device comprising a. delete The method of claim 1, The lens barrel, And a seating groove in which the friction part is in contact with the piezoelectric unit and the friction part is seated. The method of claim 3, And the seating groove and the mounting portion are formed in the lens barrel to face each other. The method of claim 1, And the housing includes an exposure hole open to expose the piezoelectric unit to the accommodation space. The method of claim 1, The piezoelectric unit includes a piezoelectric element mounted on a substrate and exposed to the accommodation space, and an elastic member for closely contacting the piezoelectric element to the lens barrel. The method of claim 6, The piezoelectric unit includes a nonconductive flexible member interposed between the piezoelectric element and the elastic member.

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