TWI477877B - Camera module - Google Patents

Description

Camera module

The invention relates to a camera module, and in particular to a camera module capable of smoothly moving and accurately positioning a lens.

Mobile phones have become the most popular handheld electronic devices. In addition to communication functions, mobile phones integrate other functions, such as photography, photography, Internet access, and music playback. Among them, the camera module is the basic equipment of the current smart phone, and the miniaturization and high-definition camera module is the current development trend of the market. In order to improve the sharpness of the image, the camera module of the handheld device is developed by the fixed focus image capturing function toward the optical autofocus function or even the optical focusing function.

The principle of the optical autofocus function is to move the lens in the image capturing module appropriately according to different distances and close distances of the target object, so that the optical image of the image capturing object can be accurately focused on the image sensor. To produce a clear image. At present, it is common to activate the lens movement in the image capturing module, which includes stepping motor actuation, piezoelectric actuation, and voice coil motor (VCM) actuation.

In general, the mechanism of the voice coil motor is mainly composed of a coil placed in a magnetic circuit containing a permanent magnet, so that according to Fleming's left-hand rule, when the coil is electrically conductive, it will interact with the permanent magnet. The lens assembly of the permanent magnet is moved to move, and then the lens assembly fixed in the carrier is driven, and the optical current is adjusted by adjusting the current flowing through the coil. However, the speed of actuation/reset change of the voice coil motor is slower than that of other actuation modes with a variable speed of several milliseconds, and the positioning is less accurate.

In terms of positioning, conventional techniques use parallel shafts to limit the movement of moving parts. The moving direction is to assist in positioning, but the two-axis production assembly is difficult to maintain good verticality and parallelism, and the axial hole gap causes tilting and affects optical quality.

The invention provides a camera module with a double shrapnel design to suspend the movable member and cooperate with the position sensing element to achieve the effect of accurate positioning and smooth movement.

The present invention provides a camera module including a lens, a lens actuating device and an image sensing module, wherein the lens actuating device is configured to provide a lens, which comprises a fixing member, a movable member, a first elastic piece and a second elastic piece. , drive unit and position sensing element. The fixture has a coil assembly and a position sensing element. The movable member has at least one magnetic member and is movably disposed in the fixed member. The first elastic piece connects a first end surface of the fixing member and the movable member. The second elastic piece is connected to a second end surface of the fixing member and the movable member. Wherein, the movable member is suspended between the first elastic piece and the second elastic piece, and the position sensing element senses the position of the movable piece according to the change of the magnetic field.

In summary, the camera module of the present invention suspends the movable member with a double elastic piece, and uses the position sensor to sense the position of the movable member to achieve the effect of accurate positioning and stable movement.

The above described features and advantages of the present invention will be more apparent from the following description.

In the following, the invention will be described in detail by the embodiments of the invention, and the same reference numerals are used in the drawings.

Please refer to FIG. 1A and FIG. 1A simultaneously to illustrate a camera module according to an embodiment of the invention. Schematic diagram. The camera module 100 includes an image sensing module 101, a lens 102 and a lens actuating device 103. The lens actuating device 103 is used to set the position of the lens 102 and the moving lens 102 to achieve the function of adjusting the focal length. The lens actuating device 103 includes a fixing member 110, a movable member 120, elastic pieces 140, 150, a driving unit 104, and a position sensing element 160. The driving unit 104 includes a coil assembly 170 and a magnetic element 180, wherein the coil assembly 170 is disposed on the movable member 120, and the magnetic member 180 is disposed on the fixed member 110. The drive unit 104 can adjust the current through the coil assembly 170 to generate a different magnetic field, thereby pushing the movable member 120. The driving force and driving direction of the driving member 104 to the movable member 120 are determined by the magnetic field direction and magnetic field strength of the coil assembly 170 and the magnetic member 180. The image sensing module 101 is combined with the lens actuator 103 to sense an image via the lens 102 and convert it into an electrical signal output. The image sensing module 101 has an image sensing element, such as a CCD (charge-couple device), but the embodiment does not limit the type of the image sensing element.

Please refer to FIG. 1A and FIG. 1B simultaneously. FIG. 1B is a partially exploded view of the lens actuator device 103 according to an embodiment of the present invention. The fixing member 110, the movable member 120 and the elastic pieces 140, 150 disposed on the upper and lower end faces 111, 112 of the fixing member 110. The fixture 110 has a coil assembly 170 and a position sensing element 160, and the movable member 120 has at least one magnetic element 180, typically composed of two permanent magnets or magnetic materials, which are disposed on the sides of the movable member 120. The movable member 120 is provided in the fixing member 110 and movable along the optical axis to adjust the position of the lens 102.

The position sensing element 160 is, for example, a Hall element that can be used to sense the position of the movable member 120. The elastic piece 140 includes a positioning portion 142 , a flange portion 144 and a braking portion 146 . The positioning portion 142 is fixed to the end surface 111 of the fixing member 110 , and the braking portion 146 is fixed to the moving member 120 . The elastic piece 150 is similar in structure to the elastic piece 140 and is fixed to the end surface 112 of the fixing member 110 and the other side of the moving member 120. mobile The member 120 is suspended between the two elastic pieces 140, 150 and is movably disposed in the fixing member 110.

When the coil assembly 170 is energized, an electromagnetic field is generated, and the electromagnetic thrust generated by the electromagnetic field interacting with the magnetic lines of the magnetic element 180 can axially move the movable member 120 relative to the fixed member 110. The movement of the movable member 120 causes the braking portion 146 of the elastic pieces 140, 150 to deform the elastic pieces 140, 150. The braking portion 146 of the elastic pieces 140, 150 generates an elastic restoring force to the movable member 120. When the movable member 120 reaches the positioning point, the current conducted by the coil assembly 170 maintains a constant value, so that the electromagnetic thrust and the restoring force are balanced, and the movable member 120 is maintained at a fixed position. That is, the positioning of the movable member 120 is determined by the interaction of the electromagnetic thrust provided by the coil assembly 170 with the restoring force provided by the elastic sheets 140, 150.

In the embodiment, the camera module 100 does not need to provide a shaft to limit the moving direction of the movable member 120, but directly replaces the shaft by two elastic pieces 140, 150 to limit the moving direction of the movable member 120. The elastic piece 140 and the elastic piece 150 are respectively disposed on the two end faces 111, 112 of the fixing member 110, and the movable member 120 is suspended between the elastic piece 140 and the elastic piece 150. Since the movable member 120 is disposed between the elastic sheets 140, 150 in a suspended manner, the movable member 120 is relatively stable when moved, and is not affected by the assembly precision of the mechanical assembly or the axial hole gap. The movable member 120 does not cause problems such as tilt or offset when moving. In addition, the structure without the shaft can reduce assembly complexity and production costs.

The position sensing element 160 is, for example, a magnetic field change sensing element, a light intensity change sensing element, an electric field change sensing element, or a stress change sensing element. In the present embodiment, the position sensing element 160 is implemented as a Hall element, which is typically used as a magnetic field detection and magnetic field measurement element. When the magnetic field passes through the Hall element, the Hall element produces a corresponding voltage. Connect this voltage to an op amp for comparison or amplification, The change in the magnetic field can be measured. As the magnetic element 180 moves, the magnetic field around it moves and changes. The position sensing element 160 can sense a change in the magnetic field caused by the movement of the magnetic element 180, thereby obtaining the correct position of the movable member 120. The driving circuit (not shown) of the camera module 100 adjusts the current of the coil assembly 170 according to the voltage signal sensed by the position sensing component 160 to achieve an accurate positioning effect. With the position sensing component 160, the camera module 100 can achieve an accurate and fast lens 102 positioning effect.

The camera module 100 further includes a control unit 161 disposed on the fixture 110. The control unit 160 is configured to receive a target position signal and receive an actual position signal from the position sensing component 160. The control unit 161 compares the target position signal with the actual position signal, and adjusts the driving direction and the driving force of the driving unit 104 accordingly. The control unit 161 may be formed by a wafer or a circuit board, and may be integrated with the position sensing element 160 as a position sensing and control unit 162 for sensing the position of the movable member 120 and adjusting the driving direction and driving force of the driving unit 104.

Please refer to FIG. 2 , which is a schematic structural view of the elastic piece of the embodiment. The elastic piece 140 has two oppositely disposed positioning portions 142, and the other two opposite corners have two braking portions 146 to be coupled to the movable member 120. A flange portion 144 is provided between the adjacent positioning portion 142 and the braking portion 146. The crotch portion 144 is provided with a shock absorbing member 145, and the shock absorbing member 145 may be a plastic material such as a silica gel. The shock absorbing member 145 is coupled between the gaps of the crotch portion 144 to slow the opening speed of the crotch portion 144 and to absorb the sway of the crotch portion 144, thereby generating an appropriate cushioning damping effect to reduce the amplitude and time of the oscillation. When the movable member 120 moves, the braking portion 146 of the elastic piece 140 is pushed up or pulled by the movable member 120 to deform the crotch portion 144. The deformation of the crotch portion 144 provides an elastic restoring force to the movable member 120. The shock absorbing member 145 can be disposed in a certain gap of the crotch portion 144, which is the maximum opening interval of the flexible deformation region in the crotch portion 144. Gap. The structure of the elastic piece 150 is similar to that of the elastic piece 140, and will not be described again.

The elastic piece 140 and the elastic piece 150 can be realized by using different elastic structure. Referring to FIG. 3, a schematic structural view of the elastic piece according to another embodiment of the present invention is shown. The elastic piece 340 includes a positioning portion 342 and a braking portion 346 which are disposed opposite to each other. The inner frame piece 347 and the outer frame piece 348 replace the flange portion 144 in the elastic piece 140. The shock absorbing member 345 is disposed between the inner frame piece 347 and the outer frame piece 348 and connects the inner frame piece 347 and the outer frame piece 348. The shock absorbing member 345 is made of, for example, an elastic material such as silica gel or rubber to reduce the amplitude and time of oscillation of the movable member 120. The structure of the shrapnels 140, 340 can be implemented by various embodiments. After the description of the above embodiments, other embodiments are known in the art, and no further details are provided herein.

The fixing member 110 in FIG. 1 has the function of supporting, and the movable member 120 can be equipped with a lens module (not shown) to achieve the effect of focusing. FIG. 1 is only a schematic structural view of the fixing member 110 and the movable member 120, and the present invention is not limited to FIG. In addition, the movable member 120 of the camera module 100 of the present invention is used to set the lens 102 (or lens) to achieve the effect of focusing. Since the upper and lower ends of the movable member 120 are respectively provided with the elastic pieces 140, 150, the movable member 120 can be sandwiched between the elastic pieces 140, 150, thereby achieving the effect of stably moving the movable member 120. In addition, the camera module 100 of the present invention can be connected to a driving circuit (not shown) according to design requirements. The driving circuit can be used to control the coil assembly 170 to move the movable member 120 and receive the signal output by the position sensing element 160.

In addition, it should be noted that the components in the above embodiments may be added, removed, adjusted or replaced according to their functions and design requirements, and the invention is not limited. After the description of the above embodiments, those skilled in the art should be able to deduce the embodiments thereof, and no further details are provided herein.

In summary, the camera module of the present invention utilizes two elastic pieces to suspend the movable piece, and cooperates with the position sensing component to achieve accurate positioning and smooth movement of the lens. effect.

Although the preferred embodiments of the present invention have been disclosed as above, the present invention is not limited to the above-described embodiments, and any one of ordinary skill in the art can make some modifications without departing from the scope of the present invention. The scope of protection of the present invention should be determined by the scope of the appended claims.

100‧‧‧ camera module

101‧‧‧Image Sensing Module

102‧‧‧ lens

103‧‧‧Lens actuating device

104‧‧‧ drive unit

110‧‧‧Fixed parts

111, 112‧‧‧ end face

120‧‧‧Active parts

140, 150‧‧ ‧ shrapnel

142‧‧‧ Positioning Department

144‧‧‧蜿蜒

145, 345 ‧ ‧ shock absorbers

146‧‧‧ Brake

160‧‧‧ Position sensing components

161‧‧‧Control unit

162‧‧‧ Position Sensing and Control Unit

170‧‧‧ coil assembly

180‧‧‧Magnetic components

340‧‧‧Shrap

342‧‧‧ Positioning Department

346‧‧‧ Brake

347‧‧‧Inside frame

348‧‧‧Outer film

FIG. 1A is a schematic diagram of a camera module according to an embodiment of the invention.

1B is a partial exploded view of an embodiment of the present invention.

FIG. 2 is a schematic view showing the structure of the elastic piece of the embodiment.

3 is a schematic structural view of a shrapnel according to another embodiment of the present invention.

100‧‧‧ camera module

101‧‧‧Image Sensing Module

102‧‧‧ lens

103‧‧‧Lens actuating device

104‧‧‧ drive unit

110‧‧‧Fixed parts

111, 112‧‧‧ end face

120‧‧‧Active parts

140, 150‧‧ ‧ shrapnel

142‧‧‧ Positioning Department

144‧‧‧蜿蜒

145‧‧‧ Shock absorbers

146‧‧‧ Brake

160‧‧‧ Position sensing components

161‧‧‧Control unit

162‧‧‧ Position Sensing and Control Unit

170‧‧‧ coil assembly

180‧‧‧Magnetic components

Claims (10)

A camera module includes: a lens; a lens actuating device for arranging the lens, the lens actuating device comprising: a fixing member; a movable member disposed in the fixing member and along the lens The first elastic piece is connected to a first end surface of the fixing member and the movable member, and the first elastic piece has a first positioning portion, a first clamping portion and a first braking portion, and the first elastic portion a first portion is connected to the first positioning portion and the first braking portion, wherein the first positioning portion is fixed to the first end surface of the fixing member, and the first braking portion is fixed to the movable member; a second elastic piece connecting a second end surface of the fixing member and the movable member, and the second elastic piece has a second positioning portion, a second clamping portion and a second braking portion, wherein the second elastic portion is connected to the second elastic portion a second positioning portion and the second braking portion, wherein the second positioning portion is fixed to the second end surface of the fixing member, and the second braking portion is fixed to the movable member; a driving unit is disposed on the fixing portion Between the workpiece and the movable member; a position sensing element disposed on the fixing member; An image sensing module is configured to sense an image through the lens in the lens actuating device; wherein the lens is disposed on the movable member, and the movable member is suspended between the first elastic piece and the second elastic piece, The driving unit provides a driving force for moving the movable member, the deformation of the first jaw and/or the deformation of the second jaw to provide an elastic restoring force to the movable member, and the position sensing element is used for Sensing the activity s position. The camera module of claim 1, wherein the driving unit comprises at least one magnetic component and at least one coil component, wherein the at least one magnetic component is disposed on the movable component, and the at least one coil component is disposed on the fixed component. Pieces. The camera module of claim 1, wherein the position sensing element is a magnetic field change sensing element, a light intensity change sensing element, an electric field change sensing element or a stress change sensing element. The camera module of claim 3, wherein the position sensing element is a Hall element. The camera module of claim 1, wherein the first elastic piece further comprises a shock absorbing member disposed in a gap of the crotch portion. The camera module of claim 5, wherein the shock absorbing member is a silica gel. The camera module of claim 1, wherein the second elastic piece further comprises a shock absorbing member disposed in a gap of the second crotch portion. The camera module of claim 7, wherein the shock absorbing member is a tantalum gel. The camera module of claim 1, further comprising a control unit, the control unit is disposed on the fixing component, the control unit is configured to receive a target position signal, and receive the sensing component from the position An actual position signal, the control unit compares the target position signal with the actual position signal, and adjusts a driving direction and a driving force of the driving unit accordingly. The camera module of claim 9, wherein the position sensing component and the control unit are integrated into a position sensing and control unit, the position The sensing and control unit is disposed on the fixing member for sensing the position of the moving member and adjusting the driving direction and the driving force of the driving unit.