CN109089020B

CN109089020B - Optical system

Info

Publication number: CN109089020B
Application number: CN201810427198.XA
Authority: CN
Inventors: 陈树山; 游证凯; 胡朝彰
Original assignee: TDK Taiwan Corp
Current assignee: TDK Taiwan Corp
Priority date: 2017-06-13
Filing date: 2018-05-07
Publication date: 2021-06-04
Anticipated expiration: 2038-05-07
Also published as: CN208158722U; CN109089020A; CN208752322U

Abstract

The present disclosure provides an optical system including a fixed portion, a movable portion, a driving coil, a circuit loop and a magnetic element. The fixed part comprises a base and a circuit board, and the movable part comprises an optical element bearing piece configured to bear an optical element. The magnetic element corresponds to the driving coil and is configured to generate an electromagnetic driving force to drive the optical element carrier to move relative to the base. The driving coil and the circuit loop are integrally formed on the circuit board, and the driving coil and the circuit loop are partially overlapped when viewed along a direction perpendicular to an optical axis of the optical element.

Description

Optical system

Technical Field

The present invention relates to an optical system, and more particularly, to an optical system having a circuit board integrally formed with a flat coil.

Background

With the development of technology, many electronic devices (such as smart phones or tablet computers) have a function of taking pictures or recording videos. Through the camera module arranged on the electronic device, a user can operate the electronic device to capture various photos.

The development trend of the electronic devices with camera function is continuously moving toward ultra-thinning. Generally, a camera module includes a lens carrier, a plurality of magnets, a plurality of coils, and a circuit board, which are stacked in the same direction, for example, in the optical axis direction of the lens. However, such a stacking method increases the overall height of the camera module, so that the height of the camera module cannot be further reduced when the thickness of the electronic device needs to be reduced for miniaturization.

Therefore, how to reduce the thickness of the camera module to achieve the purpose of miniaturization is an issue worth of discussion and solution.

Disclosure of Invention

In view of the above, the present disclosure provides an optical system to solve the above problems.

An embodiment of the present disclosure discloses an optical system, which includes a fixed portion, a movable portion, a driving coil, a circuit loop, and a magnetic element. The fixed part comprises a base and a circuit board, and the movable part comprises an optical element bearing piece configured to bear an optical element. The magnetic element corresponds to the driving coil and is configured to generate an electromagnetic driving force to drive the optical element carrier to move relative to the base. The driving coil and the circuit loop are integrally formed on the circuit board, and the driving coil and the circuit loop are partially overlapped when viewed along a direction perpendicular to an optical axis of the optical element.

In some embodiments, the circuit loop has a line that does not overlap the driving coil when viewed along the optical axis.

In some embodiments, the thickness of the circuit board is slightly less than or equal to the thickness of the drive coil.

In some embodiments, the drive coil includes a plurality of winding layers, and a portion of the winding layers are included in the circuit loop.

In some embodiments, the optical system further includes a position sensor disposed on the circuit board, and the position sensor partially overlaps the driving coil when viewed from a direction perpendicular to the optical axis.

In some embodiments, the base includes a receiving cavity configured to receive the position sensor and the drive coil.

In some embodiments, the base includes a retaining wall disposed in the receiving cavity and between the position sensor and the driving coil.

In some embodiments, the optical element carrier further includes a metal abutting member for limiting the optical element carrier to a limit position.

In summary, the present disclosure provides an optical system including a circuit loop, a circuit board and a flat coil. The flat coil and the circuit loop are integrally formed in the circuit board, so that the overall height of the flat coil and the circuit board in the Z-axis direction can be reduced, the height of the optical system in the Z-axis direction is further reduced, and the purpose of miniaturization is achieved.

In addition, in some embodiments, a portion of the winding layer of the flat coil is contained within the circuit loop. That is, the circuit loop in the circuit board shares the area in the flat coil with the partial winding layer of the flat coil, so that the length of the circuit board in the X-axis direction and the Y-axis direction can be reduced, and the purpose of miniaturizing the optical system is further achieved.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosed principles. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the principles disclosed herein.

Drawings

Fig. 1 is a schematic diagram of an optical system according to an embodiment of the disclosure.

Fig. 2 is an exploded view of components of an optical system according to an embodiment of the present disclosure.

Fig. 3 shows a cross-sectional view taken along line a-a' in fig. 1.

Fig. 4 is a sectional view taken along the line B-B' in fig. 1 according to an embodiment of the present disclosure.

Fig. 5 is a schematic cross-sectional view of a base, a circuit board, and a flat coil according to another embodiment of the disclosure.

Fig. 6 is a schematic cross-sectional view of a base, a circuit board, and a flat coil according to another embodiment of the present disclosure.

Fig. 7 is a schematic cross-sectional view of an optical system according to another embodiment of the present disclosure.

Description of reference numerals:

100. 100A optical system

102 shell

1021 shell opening

1023 the space

104 frame

1041 groove

1043 central opening

1045 projection

106 upper reed

108 optical element carrier

1081 through hole

110 lower reed

112 base

1121 base opening hole

1123 accommodating groove

1125 retaining wall

114. 114A circuit board

1141 circuit loop

1143 electric contact

116 second elastic element

118 position sensor

120 metal abutting part

DCL flat coil

L1-L8 winding layer

MEG1 first magnetic element

MEG2 second magnetic element

O optical axis

T1, T2 thickness

Detailed Description

In order to make the objects, features and advantages of the present disclosure more comprehensible, embodiments accompanied with figures are described in detail below. The configuration of the elements in the embodiments is illustrative and not intended to limit the disclosure. And the reference numbers in the embodiments are partially repeated to simplify the description, and do not indicate the relevance between the different embodiments. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are directions with reference to the attached drawings only. Accordingly, the directional terminology used is intended to be in the nature of words of description rather than of limitation.

Furthermore, relative terms, such as "lower" or "bottom" and "upper" or "top," may be used in embodiments to describe one element's relative relationship to another element as illustrated. It will be understood that if the device is turned over, with the top and bottom of the device reversed, elements described as being on the "lower" side will be turned over to elements on the "upper" side.

As used herein, the term "about" generally means within 20%, preferably within 10%, and preferably within 5% of a given value or range. The amounts given herein are approximate, meaning that the meaning of "about" or "approximately" may still be implied without particular recitation.

Referring to fig. 1 to 3, fig. 1 is a schematic diagram of an optical system 100 according to an embodiment of the disclosure, fig. 2 is an exploded view of the optical system 100 according to an embodiment of the disclosure, and fig. 3 shows a cross-sectional view along a line a-a' in fig. 1. The optical system 100 may be a camera system having an optical driving component for carrying an optical element (e.g., a lens, not shown), and the optical system 100 may be installed in various electronic devices or portable electronic devices (e.g., a smart phone or a tablet computer) for a user to perform an image capturing function. In this embodiment, the optical driving component may be a Voice Coil Motor (VCM) with an Auto Focus (AF) function, but is not limited thereto. In some embodiments, the Optical driving components of the Optical system 100 may also have Auto Focusing (AF) and Optical Image Stabilization (OIS) functions.

With continued reference to fig. 2, fig. 2 shows an exploded view of the optical system 100 according to an embodiment of the disclosure. The optical system 100 includes a housing 102, a frame 104, an upper spring 106, an optical element carrier 108, a first magnetic element MEG1, four second magnetic elements MEG2, a lower spring 110, a base 112, and a circuit board 114. The base 112 can be fixedly connected to the housing 102 to define a fixing portion, and the connecting manner can be a riveting, a clamping, or a welding manner, but is not limited thereto, as long as the base 112 can be fixedly connected to the housing 102, and the scope of the disclosure is included. The fixing portion may include other elements, such as the circuit board 114, in other embodiments. Furthermore, the optical element carrier 108 and the frame 104 may be defined as a movable portion that moves relative to the fixed portion.

The housing 102 has a hollow structure and is formed with a housing opening 1021, the base 112 is formed with a base opening 1121, the center of the housing opening 1021 corresponds to an optical axis O of an optical element (not shown) carried by the optical element carrier 108, and the base opening 1121 corresponds to an image sensor (not shown) disposed below the base 112. The housing 102 may have a receiving space 1023 for receiving the frame 104, the upper spring 106, the optical element carrier 108, the first magnetic element MEG1, the second magnetic elements MEG2, and the lower spring 110. In addition, the housing 102 can also accommodate the circuit board 114 and the base 112. Furthermore, the first magnetic element MEG1 and the second magnetic elements MEG2 corresponding to the first magnetic element MEG1 can be defined as the aforementioned optical driving assembly, electrically connected to the circuit board 114 and driving the optical element carrier 108 to move along the optical axis O relative to the base 112.

As shown in fig. 2, the optical element carrier 108 has a hollow ring structure and a through hole 1081, wherein a corresponding locking thread structure (not shown) is disposed between the through hole 1081 and the optical element, so that the optical element is locked in the through hole 1081. In this embodiment, the first magnetic element MEG1 is disposed around the optical element carrier 108. In addition, the frame 104 has a plurality of slots 1041 and a central opening 1043. In this embodiment, the frame 104 has four grooves 1041 for accommodating the four second magnetic elements MEG2, but the number of the grooves 1041 and the second magnetic elements MEG2 is not limited to this embodiment. In this embodiment, the second magnetic element MEG2 may have a long bar shape, but is not limited thereto, and may have a different shape in other embodiments.

The optical element carrier 108 and the optical elements are disposed in the central opening 1043 and can move relative to the frame 104. More specifically, as shown in fig. 3, the optical element carrier 108 can be suspended in the central opening 1043 by connecting the upper spring 106 and the lower spring 110 to the frame 104. When the first magnetic element MEG1 is powered on, the four second magnetic elements MEG2 generate an electromagnetic driving force (electromagnetic force) with the first magnetic element MEG1, thereby driving the optical element carrier 108 to move along the optical axis O (Z-axis direction) relative to the frame 104 and the base 112 for Auto Focusing (Auto Focusing). In some embodiments, the second magnetic element MEG2 may include at least one multi-pole magnet (multipole magnet) for inducing the corresponding first magnetic element MEG1 and driving the optical element carrier 108 to move along the optical axis O for focusing.

It should be understood that the upper spring plate 106 and the lower spring plate 110 can be a first elastic element, respectively. In this embodiment, the upper spring plate 106 can be two separate spring plates, and the lower spring plate 110 can be integrally formed, but is not limited thereto. For example, the upper spring 106 may be integrally formed in other embodiments.

As shown in fig. 2, the Circuit board 114 is disposed on the base 112, and in this embodiment, the Circuit board 114 may be a Flexible Printed Circuit (FPC), but is not limited thereto. Furthermore, the optical system 100 further includes a circuit loop 1141 and four flat coils DCL disposed on the circuit board 114. In this embodiment, the planar coil DCL is used as a driving coil, and the circuit loop 1141 and the four planar coils DCL are integrally formed on or in the circuit board 114. In this embodiment, the circuit loop 1141 is a conductive wire on the circuit board 114 and is configured to electrically connect the flat coil DCL and at least one electrical contact 1143. As shown in fig. 2, the circuit board 114 has a plurality of electrical contacts 1143 configured to connect to a main circuit board (not shown) of the electronic device. It is noted that four plate coils DCL are disposed corresponding to the second magnetic elements MEG2, respectively.

In addition, as shown in fig. 2, the optical system 100 further includes four second elastic elements 116, wherein each of the second elastic elements 116 has a strip-shaped structure, such as a column-shaped or a line-shaped structure, but is not limited thereto. One end of each second elastic element 116 is connected to the upper spring 106, and the other end of the second elastic element 116 is connected to the circuit board 114. With the above-mentioned structure configuration, the optical element carrier 108 and the optical element (not shown) and the frame 104 carried thereby can move along the direction of the X-Y plane relative to the base 112 through the four flexible second elastic elements 116.

In this embodiment, when the flat coil DCL in the circuit board 114 is energized, an electromagnetic driving force is induced by the corresponding second magnetic element MEG2, thereby driving the optical element carrier 108, the optical element and the frame 104 to move along the X-Y plane. Therefore, if the Optical system 100 is shaken, the Optical element carrier 108 can be driven by the electromagnetic driving force to move on the X-Y plane to compensate the movement of the Optical system 100 when the Optical system 100 is shaken, thereby achieving the purpose of Optical anti-shake (Optical Image Stabilization). In addition, the optical system 100 may also include at least one position sensor 118 configured to sense a displacement of the optical element carrier 108 relative to the base 112. In this embodiment, the optical system 100 may include two position sensors 118 configured to sense displacements of the optical element carrier 108 relative to the base 112 along the X-axis and the Y-axis, respectively. It is noted that the number of position sensors 118 is not limited to this embodiment.

Referring to fig. 2 to 4, fig. 4 is a cross-sectional view taken along line B-B' of fig. 1 according to an embodiment of the present disclosure. For clarity, only the base 112, the circuit board 114, the flat coil DCL, and the position sensor 118 are shown in fig. 4. As shown in fig. 2 and 4, a portion of the flat coil DCL protrudes from the body of the circuit board 114 along the-Z axis direction, and the base 112 may further include four receiving slots 1123 configured to receive the corresponding flat coil DCL and the position sensor 118.

It is to be noted that, as shown in fig. 4, when viewed in a direction perpendicular to the optical axis O (e.g., in the Y-axis direction), the flat coil DCL (driving coil) is partially overlapped with the circuit loop 1141, and the position sensor 118 is partially overlapped with a portion of the flat coil DCL. For example, as shown in fig. 4, the flat panel coil DCL includes 8 winding layers L1-L8, and when viewed along the Y-axis direction, the winding layers L1 and L2 overlap the circuit loop 1141, and the winding layers L3-L8 do not overlap the circuit loop 1141. The position sensor 118 overlaps the winding layers L3 to L5, but does not overlap the winding layers L1, L2, and L6 to L8.

On the other hand, the circuit loop 1141 does not overlap with the flat coil DCL when viewed in the direction of the optical axis O. That is, the circuit loop 1141 is formed outside the region of the flat coil DCL. By this design configuration, the flat coil DCL and the corresponding second magnetic element MEG2 can provide a larger electromagnetic driving force.

Furthermore, as shown in fig. 4, in this embodiment, the circuit board 114 has a thickness T1, the flat coil DCL has a thickness T2, and the thickness T1 of the circuit board 114 is smaller than the thickness T2 of the flat coil DCL. However, in other embodiments, the thickness T2 of the flat coil DCL may be equal to the thickness T1 of the circuit board 114, which may be determined according to actual requirements.

In addition, since the planar coil DCL is integrally formed in the circuit board 114, the overall height of the planar coil DCL and the circuit board 114 in the Z-axis direction can be reduced, and the height of the optical system 100 in the Z-axis direction can be reduced, so as to achieve the purpose of miniaturization.

Referring to fig. 5, fig. 5 is a schematic cross-sectional view of a base 112, a circuit board 114A and a planar coil DCL according to another embodiment of the disclosure. This embodiment is similar to the embodiment of fig. 4, except that a portion of the winding layer of the flat-plate coil DCL is contained in the circuit loop 1141. As shown in fig. 5, the winding layers L1 and L2 of the planar coil DCL are included in the circuit loop 1141 and electrically connected to the circuit loop 1141.

Since the circuit loop 1141 in the circuit board 114 shares an area within the flat coil DCL with the winding layers L1 and L2 of the flat coil DCL (within an area between two dotted lines in fig. 5), such a structural configuration can reduce the lengths of the circuit board 114 in the X-axis direction and the Y-axis direction, thereby further miniaturizing the optical system 100.

In addition, referring to fig. 6, fig. 6 is a schematic cross-sectional view of the base 112, the circuit board 114A and the flat coil DCL according to another embodiment of the disclosure. This embodiment is similar to the embodiment shown in fig. 5, except that the base 112 may further include a retaining wall 1125 disposed in the accommodation cavity 1123 and between the position sensor 118 and the flat-panel coil DCL.

Referring to fig. 7, fig. 7 is a cross-sectional view of an optical system 100A according to another embodiment of the present disclosure. As shown in fig. 7, the optical system 100A may further include two metal abutments 120 disposed on two sides of the optical element carrier 108. Specifically, the metal contact 120 is formed on the optical element carrier 108 by in-mold injection molding (insert molding). When the optical element carrier 108 is moved along the Z-axis direction by the electromagnetic driving force, the metal abutting member 120 may limit the optical element carrier 108 at an extreme position, for example, an upper extreme position or a lower extreme position by abutting against the protrusion 1045 of the frame 104 or the second magnetic element MEG2, so as to prevent the optical element carrier 108 from colliding with other elements in the optical system 100A and being damaged.

Since the metal abutting member 120 is made of a metal material, the metal abutting member 120 has higher strength than plastic, and the height of the optical element carrier 108 along the Z-axis direction can be further reduced, so that the optical system 100A can be miniaturized.

In summary, the present disclosure provides an optical system including a circuit loop 1141, a circuit board 114 and a planar coil DCL. The planar coil DCL and the circuit loop 1141 are integrally formed in the circuit board 114, so that the overall height of the planar coil DCL and the circuit board 114 in the Z-axis direction can be reduced, and the height of the optical system 100 in the Z-axis direction can be reduced, thereby achieving the purpose of miniaturization.

Additionally, in some embodiments, a portion of the winding layer of the flat-plate coil DCL is contained within the circuit loop 1141. That is, the circuit loop 1141 in the circuit board 114 and the partial winding layer of the flat coil DCL share the region in the flat coil DCL, so that the lengths of the circuit board 114 in the X-axis direction and the Y-axis direction can be reduced, and the optical system 100 can be further miniaturized.

Although embodiments of the present disclosure and their advantages have been disclosed above, it should be understood that various changes, substitutions and alterations can be made herein by those skilled in the art without departing from the spirit and scope of the disclosure. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but rather, the process, machine, manufacture, composition of matter, means, methods and steps, presently existing or later to be developed, that will be obvious to one having the benefit of the present disclosure, may be utilized in the practice of the present disclosure. Accordingly, the scope of the present disclosure includes the processes, machines, manufacture, compositions of matter, means, methods, and steps described above. In addition, each claim constitutes a separate embodiment, and the scope of protection of the present disclosure also includes combinations of the respective claims and embodiments.

Claims

1. An optical system, comprising:

a fixing part including a base and a circuit board;

a movable part including an optical element bearing member configured to bear an optical element;

a drive coil;

a circuit loop; and

a magnetic element corresponding to the driving coil and configured to generate an electromagnetic driving force to drive the optical element carrier to move relative to the base;

the driving coil and the circuit loop are integrally formed on the circuit board, and the driving coil and the circuit loop are partially overlapped when viewed along a direction perpendicular to an optical axis of the optical element.

2. The optical system of claim 1, wherein the circuit loop has a line that does not overlap the drive coil when viewed along the optical axis.

3. The optical system of claim 1, wherein the thickness of the circuit board is slightly less than or equal to the thickness of the drive coil.

4. The optical system of claim 1, wherein the drive coil comprises a plurality of winding layers, and a portion of the plurality of winding layers is contained within the circuit loop.

5. The optical system of claim 1, wherein the optical system further comprises a position sensor disposed on the circuit board and partially overlapping the driving coil when viewed from a direction perpendicular to the optical axis.

6. The optical system of claim 5, wherein the base includes a receptacle configured to receive the position sensor and the drive coil.

7. The optical system of claim 6, wherein the base comprises a dam wall disposed in the receptacle and between the position sensor and the drive coil.

8. The optical system of claim 1, wherein the optical element carrier further comprises a metal abutment member for limiting the optical element carrier to an extreme position.