Camera module and method of operating the same

Abstract

A camera module according to an embodiment includes a lens assembly, a lens driving unit for moving the lens assembly in an optical axis direction, a position sensor unit for detecting a position of the lens assembly, and a control unit for outputting a driving signal for moving the lens assembly to a target position to the lens driving unit based on the position of the lens assembly detected by the position sensor unit, wherein the position sensor unit includes a plurality of sensor units having at least one output terminal interconnected with each other, an amplifier commonly connected with the plurality of sensor units, and an analog-to-digital converter connected to the amplifier.

Description

[0001] This application is a divisional application of the patent application filed on May 9, 2019, with application number 201980046425.7 and invention title "Camera Module and Operating Method Thereof". Technical Field

[0002] The embodiments relate to a camera module and its operation method. Background Technology

[0003] The camera module performs the function of capturing objects and storing them as images or videos, and is installed in mobile terminals such as mobile phones, laptops, drones, and vehicles.

[0004] In addition, the ultra-compact camera module is housed in portable devices such as smartphones, tablets, and laptops, and the aforementioned camera module can perform autofocus (AF) function, that is, to align the focal length of the lens by automatically adjusting the distance between the image sensor and the lens.

[0005] Autofocus is an essential function in camera modules for capturing clear still images or videos. Regarding autofocus, when a position sensor detects the position of the lens barrel containing a magnet, and a drive signal is provided to the drive unit based on the detected lens barrel position and the input target position, a driving force is generated between the coil of the drive unit and the magnet mounted in the lens barrel, causing the lens barrel to move to the focal position, thus executing the autofocus function.

[0006] However, the position sensor installed to provide the aforementioned autofocus function may provide detection signals that include ambient noise, etc., so the position of the lens barrel cannot be adjusted to the accurate position.

[0007] Furthermore, the camera module in portable devices contains electromagnetic components that are close to the camera module's components, thus exhibiting high-frequency noise characteristics; therefore, low-noise technology is essential. Additionally, while conventional position sensors can improve noise characteristics through signal processing at the drive unit stage, there are limitations to improving noise characteristics solely through signal processing. Summary of the Invention

[0008] [Technical Issues]

[0009] According to embodiments of the present invention, a camera module and its operation method are provided to increase the position detection range by detecting the position of the lens barrel based on differential signals from multiple position sensors.

[0010] Furthermore, according to embodiments of the present invention, a camera module and its operation method are provided to acquire differential values ​​at the front-end terminal of a sensing unit.

[0011] In the proposed embodiments, the technical problems to be solved are not limited to those described above. Other technical problems not mentioned herein can be clearly understood by those skilled in the art based on the embodiments described below.

[0012] [Technical Solution]

[0013] The camera module according to an embodiment includes: a lens assembly; a lens driving unit for moving the lens assembly in an optical axis direction; a position sensor unit for detecting the position of the lens assembly; and a control unit configured to output a drive signal to the lens driving unit for moving the lens assembly to a target position based on the position of the lens assembly detected by the position sensor unit, wherein the position sensor unit includes a plurality of sensor units having at least one output terminal interconnected with each other, an amplifier commonly connected to the sensor units, and an analog-to-digital converter connected to the amplifier.

[0014] Furthermore, the amplifier includes an inverting terminal and a non-inverting terminal. The inverting terminal of the amplifier can be connected to the first output terminal of the first sensor unit in the sensor unit, and can be connected to the second output terminal of the second sensor unit, which is different from the first sensor unit.

[0015] In addition, the first sensor unit can be the sensor unit that is set first in the sensor unit, and the second sensor unit can be the sensor unit that is set last in the sensor unit.

[0016] In addition, the first sensor unit can be a first Hall sensor, the second sensor unit can be a second Hall sensor, the first output terminal can be the positive output terminal of the first Hall sensor, and the second output terminal can be the negative output terminal of the second Hall sensor.

[0017] In addition, the negative output terminal of the first Hall sensor can be connected to the positive output terminal of the second Hall sensor.

[0018] In addition, the first sensor unit can be a first induction coil, the second sensor unit can be a second coil, the first output terminal can be one end of the first induction coil, the second output terminal can be the opposite end of the second induction coil, and the opposite end of the first induction coil can be connected to one end of the second induction coil.

[0019] In addition, the sensor unit also includes a third Hall sensor disposed between the first Hall sensor and the second Hall sensor. The positive output terminal of the third Hall sensor can be connected to the negative output terminal of the first Hall sensor, and the negative output terminal of the third Hall sensor can be connected to the positive output terminal of the second Hall sensor.

[0020] In addition, the camera module also includes a switch, one end of which is connected to the inverting terminal of the amplifier, and the opposite end is selectively connected to either the negative output terminal of the first Hall sensor or the negative output terminal of the second Hall sensor.

[0021] In addition, the lens assembly includes: a first lens assembly including a zoom lens group; and a second lens assembly including a focusing lens group, and the position sensor unit includes: a first position sensor unit that detects the position of the first lens assembly; and a second position sensor unit that detects the position of the second lens assembly.

[0022] Meanwhile, the operation method of the camera module according to the embodiment includes: determining the sensing conditions of the position sensor unit; controlling a switch according to the determined sensing conditions to allow the inverting terminal of an amplifier to be connected to one of the output terminals of a first sensing unit and a last sensing unit among a plurality of sensing units; detecting the position of a lens assembly corresponding to a detection signal input to the amplifier by controlling the switch; and moving the lens assembly to a target position according to the detected position, wherein the detection includes: receiving the output signal of the first sensing unit when the inverting terminal is connected to the output terminal of the first sensing unit; and receiving a differential signal according to the combination of sensing units when the inverting terminal is connected to the output terminal of the last sensing unit.

[0023] In addition, each sensing unit may include multiple output terminals, and at least one of the output terminals of each sensing unit may be connected to the output terminal of another adjacent sensing unit.

[0024]

Beneficial Effects of the Invention

[0025] In an embodiment of the invention, multiple position sensors can be interconnected such that only the output terminal of the outermost position sensor can be connected to an amplifier. Therefore, according to the invention, the differential signals from the position sensors can be input to the input terminal of the amplifier.

[0026] According to the present invention, a differential sensing scheme can be provided, wherein the detection range is wider compared to a single sensing scheme. Furthermore, according to the present invention, the differential signal based on a combination of position sensors can be input to the input terminal of an amplifier, thereby minimizing the influence of offset noise on the path to the signal processing unit of the drive unit.

[0027] Furthermore, according to the present invention, the differential signal of the position sensor is output in a sensing unit including a position sensor, an amplifier and an analog-to-digital converter, so that the number of patterns / pins connected from the driving unit to the printed circuit board can be minimized, thereby saving space on the printed circuit board.

[0028] Furthermore, according to the present invention, the differential value of the position sensor can be obtained relative to the common-mode noise, so that excellent characteristics can be achieved not only against internal noise but also against external noise.

[0029] Furthermore, according to the present invention, depending on the usage environment of the camera module, only the detection signal from a specific position sensor can be sent to the amplifier terminals, or differential signals from multiple position sensors can be sent. Therefore, according to the present invention, optimal detection signals can be acquired in environments requiring high sensing sensitivity and a large sensing range. Attached Figure Description

[0030] Figure 1 This is a perspective view of a camera module according to one embodiment.

[0031] Figure 2 From the basis Figure 1 A perspective view of the camera module of the embodiment shown after the cover has been removed.

[0032] Figure 3a It is based on Figure 2 Perspective view of the mount in the camera module of the illustrated embodiment.

[0033] Figure 3b From the basis Figure 2 The illustrated embodiment shows a perspective view of the camera module after the mounting bracket has been removed.

[0034] Figure 4a It is based on Figure 2 A perspective view of the first lens assembly in the camera module of the illustrated embodiment.

[0035] Figure 4b It is based on Figure 2 A perspective view of the second lens assembly in the camera module of the illustrated embodiment.

[0036] Figure 4c It is based on Figure 2 A perspective view of the second housing of the second lens assembly in the camera module of the illustrated embodiment.

[0037] Figure 5a It is based on Figure 3b A conceptual diagram of the first magnetization scheme of the magnet in the camera module of the illustrated embodiment.

[0038] Figure 5b It is based on Figure 3a A conceptual diagram of the second magnetization scheme for the magnet in the camera module of the illustrated embodiment.

[0039] Figure 6 It is based on Figure 2A plan view of the camera module in the embodiment shown.

[0040] Figure 7a It is along according to Figure 6 The cross-sectional view of the camera module of the embodiment shown is taken along line A1-A1'.

[0041] Figure 7b It is along according to Figure 6 The cross-sectional view of the camera module of the embodiment shown is taken along line A2-A2'.

[0042] Figure 7c It is along according to Figure 6 The cross-sectional view of the camera module of the embodiment shown is taken along line A3-A3'.

[0043] Figure 8 This is a block diagram illustrating the internal configuration of a camera module according to an embodiment of the present invention.

[0044] Figure 9 It is shown Figure 8 A block diagram showing the detailed configuration of the position sensor unit.

[0045] Figures 10a to 10d It is used for explanation Figure 9 A diagram showing the connection relationships of the sensor units.

[0046] Figure 11 This is a diagram comparing the connection relationship of the sensor unit according to the comparative example and the connection relationship of the sensor unit according to the present invention.

[0047] Figure 12 This is a diagram illustrating the connection relationship of sensor units according to another embodiment of the present invention.

[0048] Figure 13 This is a view showing the detection range of the position sensor unit according to the comparative example.

[0049] Figure 14 This is a view showing the detection range of a position sensor unit according to an embodiment of the present invention.

[0050] Figure 15 This is a block diagram illustrating a detailed configuration of a position sensor unit according to another embodiment of the present invention.

[0051] Figure 16 This is a flowchart for step-by-step explaining the operation method of the camera module according to an embodiment of the present invention. Detailed Implementation

[0052] The embodiments will be described in detail below with reference to the accompanying drawings.

[0053] Meanwhile, when the embodiment is described as being formed “above / below” or “over / below” in each element, “above / below” or “over / below” includes two elements in direct contact with each other, or at least one other element indirectly disposed between two elements. Furthermore, the expression “above / below” or “over / below” can include not only an upward direction relative to an element, but also a downward direction relative to an element.

[0054] Furthermore, relational terms such as “above / over / above” and “below / below / below” used below do not require or imply any physical or logical relationship or order between these components or elements, but can be used to distinguish one component or element from the others.

[0055] Furthermore, in the description of the embodiments, terms such as "first" and "second" may be used to describe various elements, but these terms are used to distinguish one element from another. Additionally, terms specifically defined in consideration of the configuration and operation of the embodiments are used only to describe the embodiments and are not intended to limit the scope of the embodiments.

[0056] Figure 1 This is a perspective view of the camera module 100 according to an embodiment. Figure 2 From the basis Figure 1 The camera module 100 of the embodiment shown is a perspective view after the cover 10 is removed.

[0057] First, the main reference Figure 1 In the camera module 100 according to the embodiment, various optical systems can be coupled to a predetermined mounting base 20 (see [reference]). Figure 2 For example, prism 140 and lens assembly can be mounted on mounting base 20, and cover 10 can be coupled via hook 20H of mounting base 20.

[0058] Cover 10 can be coupled to mounting base 20. Cover 10 can cover the components housed in mounting base 20, thereby protecting the components of the camera module. Mounting base 20 can be referred to as a base.

[0059] The cover 10 can be coupled to the mounting base 20 by assembly. Alternatively, the cover 10 can be coupled to the mounting base 20 by adhesive. For example, a hook 20H can protrude from the side surface of the mounting base 20, the cover 10 can have a hole formed at a position corresponding to the hook H, and the hook of the mounting base 20 can be installed in the hole of the cover 10, so that the cover 10 and the base 20 can be coupled to each other. Furthermore, the cover 10 can be stably coupled to the mounting base 20 by using adhesive.

[0060] Furthermore, the circuit board 107 can be disposed below the mounting base 20. Additionally, the circuit board 107 can be electrically connected to a lens drive unit disposed inside the mounting base 20.

[0061] Next, refer to Figure 2 According to the camera module 100 of the embodiment, the optical system and lens driving unit may be disposed in the mounting base 20. For example, the camera module 100 according to the embodiment may include at least one of a first lens assembly 110, a second lens assembly 120, a lens group 130, a prism 140, a first driving unit 310, a second driving unit 320, a rod 50, and an image sensor unit 210.

[0062] The first lens assembly 110, the second lens assembly 120, the third lens group 130, the prism 140, the image sensor unit 210, etc., can be classified as optical systems.

[0063] Furthermore, the first driving unit 310, the second driving unit 320, the rod 50, etc., can be classified as lens driving units, and the first lens assembly 110 and the second lens assembly 120 can also be used as lens driving units. The first driving unit 310 and the second driving unit 320 can be coil driving units, but the present invention is not limited thereto.

[0064] The lever 50 can be used as a guide for moving the lens assembly, and can be a single lever or multiple levers. For example, the lever 50 may include a first lever 51 and a second lever 52, but the invention is not limited thereto.

[0065] exist Figure 2 In the axes shown, the Z-axis represents the direction of the optical axis or a direction parallel to it. The Y-axis represents the direction perpendicular to the Z-axis on the ground (YZ plane). The X-axis represents the direction perpendicular to the ground.

[0066] In this embodiment, prism 140 converts incident light into parallel light. For example, prism 140 converts incident light into parallel light by changing the optical path of the incident light to an optical axis Z parallel to the central axis of the lens group. The parallel light can then pass through the third lens group 130, the first lens assembly 110, and the second lens assembly 120, and enter the image sensor unit 210, thereby capturing an image.

[0067] In the following description of the embodiments, two movable lens groups will be described; however, the invention is not limited to this, and three, four, five, or more movable lens groups may be used. Furthermore, the optical axis direction Z refers to the direction in which the lens groups are aligned or the direction parallel to it.

[0068] The camera module according to the embodiment can perform a zoom function. For example, in the embodiment, the first lens assembly 110 and the second lens assembly 120 can be movable lenses that are moved by the first drive unit 310, the second drive unit 320 and the rod 50, and the third lens group 130 can be a fixed lens.

[0069] For example, in an embodiment, the first lens assembly 110 and the second lens assembly 120 may include a movable lens group, and the third lens group 130 may be a fixed lens group.

[0070] The third lens group 130 can be used as a focuser for imaging parallel light at a specific location.

[0071] Furthermore, the first lens assembly 110 can be used as a variator to re-image the image formed by the third lens group 130, which acts as a focuser, at another location. Simultaneously, since the distance to the object or the image distance changes significantly, the magnification in the first lens assembly 110 can change significantly, and the first lens assembly 110, as a variator, can be used as an important factor in the change of focal length or magnification of the optical system.

[0072] Meanwhile, the image point formed at the first lens assembly 110, which serves as a converter, can vary slightly depending on its position.

[0073] Therefore, the second lens assembly 120 can perform position compensation on the image formed by the transducer. For example, the second lens assembly 120 can be used as a compensator to accurately form the image point formed by the first lens assembly 110, which is the transducer, at the actual position of the image sensor unit 210.

[0074] For example, the first lens assembly 110 may be a zoom lens assembly that performs zoom function, and the second lens assembly 120 may be a focusing lens assembly that performs focusing function.

[0075] In the following text, reference will be made to Figure 3a The features of the camera module according to the embodiment are described in detail up to Figure 5d.

[0076] first, Figure 3a It is based on Figure 2 The illustrated embodiment shows a perspective view of the mounting base 20 in the camera module. The mounting base 20 may have a cuboid shape and may include four side surfaces and a bottom surface 20e. For example, the mounting base 20 may include first to fourth side surfaces 20a, 20b, 20c, and 20d, with the first side surface 20a facing the second side surface 20b and the third side surface 20c facing the fourth side surface 20d.

[0077] Hook 20H may be formed on at least one side surface of mounting base 20 and coupled to a hole in cover 10.

[0078] Furthermore, the first guide groove 112G, which includes the first lens assembly 110, the second lens assembly 120, and the third lens group 130, can be formed on the bottom surface 20e of the mounting base 20 in the optical axis direction Z. The first guide groove 112G can be recessed downwards according to the outer peripheral shape of the lens, but the present invention is not limited thereto.

[0079] Furthermore, the first opening 23a and the second opening 23b, in which the first drive unit 310 and the second drive unit 320 are disposed, can be formed in the first side surface 20a and the second side surface 20b of the mounting base 20, respectively. Additionally, the third opening 22, in which the image sensor unit 210 is disposed, can be formed in the third side surface 20c of the mounting base 20.

[0080] Furthermore, one or more fourth openings 27 can be formed in the bottom surface of the mounting base 20 through which the circuit board 107 is exposed.

[0081] Furthermore, one or more coupling holes 25 coupled to the rod 20 can be formed in each of the third side surface 20c and the fourth side surface 20d opposite to the third side surface of the mounting base 20. For example, a first coupling hole 25a, a second coupling hole 25b, a third coupling hole 25c, and a fourth coupling hole 25d can be formed in the third side surface 20c and the fourth side surface 20d of the mounting base 20, and the first rod 51, the second rod 52, the third rod 53, and the fourth rod 54 can be coupled to them respectively.

[0082] Additionally, the prism mounting portion 24 for mounting the prism 140 can be formed inside the fourth side surface 20d of the mounting base 20.

[0083] Mounting base 20 may be formed of at least one of plastic, glass-based epoxy resin, polycarbonate, metal or composite material.

[0084] Next, Figure 3b From the basis Figure 2 The illustrated embodiment is a perspective view of the camera module after removing the mounting base 20, and shows the optical system and lens drive unit.

[0085] In an embodiment, the lens driving unit may include a mover and a fixed device. The mover is the opposite of the fixed device and can be referred to as a moving part. For example, the mover may represent a lens assembly that moves by the rolling motion of a wheel. Conversely, the fixed device may represent a stationary mounting base, rod, etc.

[0086] The camera module according to the embodiment may include an optical system, such as a prism 140, a first lens assembly 110, a second lens assembly 120, a third lens group 130, and an image sensor unit 210 on the mounting base 20. Additionally, the camera module according to the embodiment may include lens driving units, such as a first driving unit 310, a second driving unit 320, and a lever 50. The first lens assembly 110 and the second lens assembly 120 may also perform lens driving functions.

[0087] Rod 50 may include first to fourth rods 51, 52, 53 and 54, and the first to fourth rods 51, 52, 53 and 54 are coupled to first coupling holes to fourth coupling holes 25a, 25b, 25c and 25d respectively (see...). Figure 3a This serves as a guide for moving the first lens assembly 110 and the second lens assembly 120. The rod 50 may be formed of plastic, glass-based epoxy resin, polycarbonate, metal, or composite material.

[0088] The first driving unit 310 may be a coil driving unit and may have a shape in which a first coil 314 is wound around a first core 312 (e.g., an iron core). Alternatively, the second driving unit 320 may also be a coil driving unit in which a second coil 324 is wound around a second core 322 (e.g., an iron core).

[0089] First, prism 140 converts the incident light into parallel light by changing its optical path to an optical axis parallel to the central axis Z of the lens group. Then, the parallel light can pass through the third lens group 130, the first lens assembly 110, and the second lens assembly 120, thereby being captured by the image sensor unit 210.

[0090] Prism 140 can be an optical component with a triangular prism shape. Alternatively, in an embodiment, a reflector or a mirror can be selected instead of prism 140.

[0091] Furthermore, according to an embodiment of the present invention, if the image sensor unit 210 is not positioned in a direction perpendicular to the optical axis, an additional prism (not shown) may be provided so that light passing through the lens group is imaged by the image sensor unit 210.

[0092] In this embodiment, the image sensor unit 210 may be configured perpendicular to the optical axis of the parallel light. The image sensor unit 210 may include a solid-state imaging device 214 disposed on the second circuit board 212. For example, the image sensor unit 210 may include a charge-coupled device (CCD) image sensor or a complementary metal-oxide-semiconductor (CMOS) image sensor.

[0093] In the embodiments, reference will be made to Figure 4a and Figure 4bThe first lens assembly 110 and the second lens assembly 120 are described in detail.

[0094] Figure 4a It is based on Figure 2 A perspective view of the first lens assembly 110 in the camera module of the illustrated embodiment. Figure 4b It is based on Figure 2 A perspective view of the second lens assembly 120 in the camera module of the illustrated embodiment. Figure 4c It is based on Figure 2 A perspective view of the second housing of the second lens assembly 120 in the camera module of the illustrated embodiment.

[0095] refer to Figure 4a According to the embodiment, the first lens assembly 110 may include at least one of a first housing 112, a first lens group 114, a first wheel 117, a third drive unit 116, and a first position sensor 118.

[0096] Additionally, refer to Figure 4b The second lens assembly 120 according to the embodiment may include at least one of the following: a second housing 122, a second lens group 124, a second wheel 127, a fourth drive unit 126, and a second position sensor 128.

[0097] The first lens assembly 110 will be described in detail below.

[0098] The first housing 112 of the first lens assembly 110 may include a first lens housing 112a and a first drive unit housing 112b. The first lens housing 112a may serve as a lens barrel, and a first lens group 114 may be mounted therein. The first lens group 114 may be a movable lens group and may include one or more lenses. The second housing 122 of the second lens assembly 120 may further include a second lens housing 122a and a second drive unit housing 122b.

[0099] A first guide groove 112G may be formed on the lower side of one end of the first lens housing 112a of the first lens assembly 110. The first lens assembly 110 may be guided by the first guide groove 112G, thereby moving linearly in the optical axis direction while sliding in contact with the second rod 52. In addition, a second guide groove 122G may be formed on the lower side of one end of the second lens housing 122a of the second lens assembly 120.

[0100] In this embodiment, since the first housing 112 is configured to move in the optical axis direction through the sliding contact between the second rod 52 and the first guide groove 112G, a camera module that performs effective autofocus and zoom functions can be realized.

[0101] Furthermore, in the embodiment, since the seek housing 122 is configured to move in the optical axis direction through the sliding contact between the first rod 51 and the second guide groove 122G, a camera module that performs effective autofocus and zoom functions can be realized.

[0102] Next, the third drive unit 116, the first wheel 117, and the first position sensor 118 can be disposed in the first drive unit housing 112b of the first lens assembly 110. The first wheel 117 may include multiple wheels, and may include a first wheel 117a and a first wheel 117b.

[0103] Additionally, the fourth drive unit 126, the second wheel 127, and the second position sensor 128 can be disposed within the second drive unit housing 122b of the second lens assembly 120. The second wheel 127 may include multiple wheels, and may include a second first wheel 127a and a second second wheel 127b.

[0104] The third driving unit 116 of the first lens assembly 110 may be a magnet driving unit, but the present invention is not limited thereto. For example, the third driving unit 116 may include a first magnet as a permanent magnet. Additionally, the fourth driving unit 126 of the second lens assembly 120 may also be a magnet driving unit. However, the present invention is not limited thereto.

[0105] For example, Figure 5a This is a conceptual diagram of a first magnetization scheme for the first magnet in the third drive unit 116 of the first lens assembly 110, wherein the N pole of the permanent magnet can be arranged to face the first drive unit 310, and the S pole can be located on the opposite side of the first drive unit 310.

[0106] In this case, based on Fleming's left-hand rule, the direction of the electromagnetic force becomes horizontal relative to the optical axis, thereby driving the first lens assembly 110.

[0107] In particular, in this embodiment, as Figure 4a As shown, the technical advantage lies in the fact that the first wheel 117, which serves as the rolling drive unit, is arranged in the first lens assembly 110 to move on the rod 50, thereby minimizing the frictional torque.

[0108] Therefore, the lens assembly, lens driving device, and camera module including the lens assembly and lens driving device according to the embodiments can minimize the frictional torque between the lens assembly and the guide rod during zooming, thereby improving driving power. Thus, according to the embodiments, the technical advantage lies in reducing power consumption and improving control characteristics when the camera module performs zooming.

[0109] at the same time, Figure 5bThis is a conceptual diagram of a second magnetization scheme for a magnet used as a first drive unit 116B in a camera module according to an embodiment.

[0110] Figure 5a The first drive unit 310, in which the first coil 314 is wound around the rod-shaped first core 312, is shown (see Figure 3b ).on the contrary, Figure 5b The first 2-drive unit 310B, in which the coil is wound around a ring-shaped core, is shown.

[0111] Therefore, in Figure 5a In the first driving unit 310, the current in the region facing the third driving unit 116 has a direction.

[0112] On the contrary, Figure 5b In the first 2-drive unit 310B, the direction of the current is different in the region facing the third drive unit 116. Therefore, both the N and S poles of the permanent magnet in the third 2-drive unit 116B can be set to face the first 2-drive unit 310B.

[0113] Refer again Figure 4a The first position sensor 118 can be disposed in the first drive unit housing 112b of the first lens assembly so that position detection and position control of the first lens assembly 110 can be performed. For example, the first position sensor 118 disposed on the first drive unit housing 112b can be configured to face the first sensing magnet (not shown) disposed on the bottom of the mounting base 20.

[0114] In addition, such as Figure 4b As shown, the second position sensor 128 can also be disposed in the second drive unit housing 122b of the second lens assembly, thereby enabling position detection and position control of the second lens assembly 120.

[0115] Next, Figure 6 It is based on Figure 2 A plan view of the camera module in the illustrated embodiment. Additionally, Figure 7a It is along according to Figure 6 The illustrated embodiment shows a cross-sectional view of the camera module taken along line A1-A1' and viewed directly in the Y-axis direction. Additionally, Figure 7b It is along according to Figure 6 The illustrated embodiment shows a cross-sectional view of the camera module taken along line A2-A2' and viewed directly in the Z-axis direction. Additionally, Figure 7c It is along according to Figure 6 The cross-sectional view of the camera module of the embodiment shown is taken along line A3-A3' and viewed directly in the Z-axis direction.

[0116] First of all, Figure 7aIn the second lens assembly 120, the second drive unit housing 122 and the fourth drive unit 126 are not cut apart from each other.

[0117] Reference Figure 7a The first lens group 114 can be mounted to the first lens housing 112a of the first lens assembly 110. The first lens group 114 can be mounted to the first lens barrel 114b.

[0118] Additionally, the second lens group 124 can be mounted to the second lens housing 122a of the second lens assembly 120. The second lens group 124 can also be mounted to the second lens barrel 124b.

[0119] Additionally, the third lens group 130 may include a third lens 134 mounted to the third lens barrel 1132.

[0120] Each of the first to third lens groups 114, 124 and 134 may include one or more lenses.

[0121] In the camera module according to the embodiment, the centers of the prism 140, the third lens group 130, the first lens group 114, and the second lens group 124 can be arranged in the optical axis direction Z.

[0122] The third lens group 130 can be configured to face the prism 140, and light emitted from the prism 140 can be incident on it.

[0123] At least one of the first to third lens groups 114, 124 and 134 can be a fixed lens. For example, the third lens group 130 can be fixed to the camera module and can not move in the optical axis direction, but the invention is not limited thereto.

[0124] For example, the mounting base 20 may include a mounting portion (not shown) that is fixedly coupled to the third lens group 130. The third lens group 130 may be mounted to the mounting portion and may be fixed to the mounting portion by adhesive.

[0125] The second lens group 124 can be spaced apart from the third lens group 130 in the optical axis direction, and can be moved in the optical axis direction. The third lens group 130 can be spaced apart from the second lens group 124 in the optical axis direction, and can be moved in the optical axis direction.

[0126] Light emitted from the third lens group 130 can enter the image sensor unit 210 located behind the third lens group 130.

[0127] The first lens group 114 and the second lens group 124 are moved in the optical axis direction, so that the distance between the first lens group 114 and the third lens group 130 and the distance between the first lens group 114 and the second lens group 124 can be adjusted, and thus the camera module can perform zoom function.

[0128] Next, Figure 7b It is along according to Figure 6 The illustrated embodiment shows a cross-sectional view of the camera module taken along line A2-A2' and viewed directly in the Z-axis direction, and shows the state in which the first first wheel 117a and the first third wheel 117c are cut in the first lens assembly 110, and the second first wheel 127a and the second third wheel 127c are cut in the second lens assembly 120.

[0129] In an embodiment, the first lens assembly 110 includes a first wheel 117a and a first wheel 117c serving as rolling drive units, and the second lens assembly 120 also includes a second wheel 127a and a second wheel 127c serving as rolling drive units, thereby rolling and moving on the first rod 51, the third rod 53, the second rod 52 and the fourth rod 54 respectively by electromagnetic force, so that the generation of frictional torque can be minimized.

[0130] Therefore, the lens assembly, lens driving device, and camera module including the lens assembly and lens driving device according to the embodiment minimize the generation of frictional torque between the guide rod 50 and the wheel of the lens assembly, which serves as a rolling drive unit to move in the optical axis direction Z during zooming, thereby improving the driving force. Furthermore, according to the embodiment, the frictional resistance between the wheel of the lens assembly and the rod 50 can be minimized, resulting in a technical advantage that power consumption during zooming of the camera module can be reduced and control characteristics can be improved.

[0131] then, Figure 7c It is along according to Figure 6 The illustrated embodiment shows a cross-sectional view of the camera module taken along line A3-A3' and viewed directly in the Z-axis direction, and shows the state in which the first second wheel 117b and the first fourth wheel 117d are cut in the first lens assembly 110, and the second second wheel 127b and the second fourth wheel 127d are cut in the second lens assembly 120.

[0132] In this embodiment, the first lens assembly 110 includes a first second wheel 117b and a first fourth wheel 117d serving as rolling drive units, and the second lens assembly 120 also includes a second second wheel 127b and a second fourth wheel 127d serving as rolling drive units, thereby rolling and moving on the first rod 51, the third rod 53, the second rod 52 and the fourth rod 54 respectively, thereby minimizing the generation of frictional torque.

[0133] Therefore, according to the embodiment, the generation of frictional torque between the wheel and rod 50 of the lens assembly is minimized during zooming, resulting in a complex technical advantage that can improve driving force, reduce power consumption, and improve control characteristics.

[0134] Figure 8 This is a block diagram illustrating the internal configuration of a camera module according to an embodiment of the present invention.

[0135] refer to Figure 8 The camera module may include an image sensor 210, an image signal processing unit 220, a display unit 230, a first lens driving unit 240, a second lens driving unit 250, a first position sensor unit 260, a second position sensor unit 270, a storage unit 280, and a control unit 290.

[0136] Image sensor 210 can process optical images of objects formed by the lens as described above. To this end, image sensor 210 can preprocess the image obtained by the lens. Furthermore, image sensor 210 can convert the preprocessed image into electrical data and output it.

[0137] An image sensor 210, configured by integrating multiple photodetectors into each pixel, can convert image information of an object into electrical data and output it. The image sensor 210 can accumulate the amount of input light and output an image captured by a lens corresponding to a vertical synchronization signal based on the accumulated light amount. Image acquisition is performed by the image sensor 210, which converts light reflected and output from the object into electrical signals. Simultaneously, a color filter is required to obtain a color image using the image sensor 210. For example, a color filter array (CFA) can be employed. A CFA allows only light representing one color per pixel to pass through, has a regularly arranged structure, and can take various forms depending on the arrangement.

[0138] The image signal processing unit 220 processes images output from the image sensor 210 on a frame-by-frame basis. The image signal processing unit 220 may also be referred to as an image signal processor (ISP).

[0139] Image signal processing unit 220 may include a lens shading compensation unit (not shown). The lens shading compensation unit can be used to compensate for lens shading phenomena (where the amount of light in the central region of the image differs from the amount of light in the peripheral region) and to compensate for the color of the central and peripheral regions of the image after receiving a lens shading setting value from control unit 270, which will be described later.

[0140] Furthermore, the lens shading compensation unit can receive shading variables set differently according to the type of illumination and process the lens shading of the image to suit the received variables. Therefore, the lens shading compensation unit can process lens shading by applying different degrees of shading according to the type of illumination. Simultaneously, the lens shading compensation unit can receive shading variables set differently according to the automatic exposure weight applied to a specific area of ​​the image and process the lens shading of the image to suit the received variables, thereby preventing saturation in the image. More specifically, when automatic exposure weight is applied to the central region of the image signal, the lens shading compensation unit can compensate for brightness variations occurring in the peripheral regions of the image signal. In other words, when image signal saturation occurs due to illumination, the light intensity gradually decreases from the center to the outside in a concentric circle shape; therefore, compared to the center, the lens shading compensation unit can amplify the peripheral signal of the image signal to compensate for brightness.

[0141] Simultaneously, the image signal processing unit 220 can measure the sharpness of the image acquired by the image sensor 210. In other words, the image signal processing unit 220 can measure the sharpness of the image to check the focusing accuracy of the image acquired by the image sensor 210. The sharpness can be measured for each image acquired based on the position of the focusing lens.

[0142] The display unit 230 displays the captured image under the control of the control unit 290, which will be described later, and displays a settings screen required for taking the picture or a screen for the user to select actions.

[0143] The first lens driving unit 240 moves the first lens assembly. Preferably, the first lens driving unit 240 can move a first lens group included in the first lens assembly. Preferably, the first lens group can be a zoom lens. In addition, the first lens driving unit 240 can move the zoom lens in the optical axis direction to adjust the zoom position (or zoom magnification) of the zoom lens.

[0144] The second lens driving unit 250 moves the second lens assembly. Preferably, the second lens driving unit 250 can move the second lens group included in the second lens assembly as described above. The second lens group may include a focusing lens. In addition, the second lens driving unit 250 can move the focusing lens in the optical axis direction to adjust the focusing position of the focusing lens.

[0145] The first position sensor unit 260 includes the first position sensor 118 described above, and therefore detects the position of the first lens assembly 110. Preferably, the first position sensor unit 260 can detect the position of the third drive unit 116 disposed in the first lens assembly 110. Preferably, the first position sensor unit 260 can detect the position of the first lens assembly 110 in order to control the position of the first lens assembly 110.

[0146] In other words, the first position sensor unit 260 provides position data for moving the first lens assembly via the first lens drive unit 240.

[0147] The second position sensor unit 270 includes the second position sensor 128 described above, and therefore detects the position of the second lens assembly 120. Preferably, the second position sensor unit 270 can detect the position of the fourth drive unit 126 disposed on the second lens assembly 120. Preferably, the second position sensor unit 270 can detect the position of the second lens assembly 120 in order to control the position of the second lens assembly 120.

[0148] In other words, the second position sensor unit 270 provides position data for moving the second lens assembly via the second lens drive unit 250.

[0149] Storage unit 280 stores data required for operating camera module 100. Specifically, storage unit 280 can store information related to the zoom position and focus position for each distance to the object. In other words, the focus position can be the position where the focusing lens accurately focuses on the object. Furthermore, the focus position can vary depending on the zoom position of the zoom lens and the distance to the object. Therefore, storage unit 280 stores data regarding the zoom position based on the distance and the focus position corresponding to the zoom position.

[0150] Control unit 290 controls the overall operation of the camera module. Specifically, control unit 290 controls first position sensor unit 260 and second position sensor unit 270 to provide autofocus functionality.

[0151] In other words, the control unit 290 enables the first position sensor unit 260 to detect the position of the first lens assembly. Preferably, the control unit 290 enables the first position sensor unit 260 to detect the current position of the first lens assembly in order to move the first lens assembly to the target position.

[0152] In addition, when the current position of the first lens assembly is detected by the first position sensor unit 260, the control unit 290 provides the first lens drive unit 240 with a control signal for moving the first lens assembly to the target position based on the current position of the first lens assembly.

[0153] Furthermore, the control unit 290 enables the second position sensor unit 270 to detect the position of the second lens assembly. Preferably, the control unit 290 enables the second position sensor unit 270 to detect the current position of the second lens assembly in order to move the second lens assembly to a target position.

[0154] In addition, when the current position of the second lens assembly is detected by the second position sensor unit 260, the control unit 290 provides the second lens drive unit 240 with a control signal for moving the second lens assembly to the target position based on the current position of the second lens assembly.

[0155] The differential signal of the detection signal detected by the multiple sensor units constituting each sensor unit is input to the control unit 290 through the first position sensor unit 260 and the second position sensor unit 270.

[0156] In other words, according to the present invention, each of the first position sensor unit 260 and the second position sensor unit 270 includes a plurality of sensor units. Furthermore, the sensor units perform a detection operation at each mounting position. According to the present invention, the positions of the first lens assembly and the second lens assembly are detected using differential signals of the detection signals acquired by the sensor units.

[0157] Typically, the control unit 290 can receive signals detected by the sensor unit, so the position of the first lens assembly or the second lens assembly can be detected based on its differential signal.

[0158] However, in the above structure, an amplifier and an analog-to-digital converter (ADC) are required in each sensor unit. Additionally, the control unit 290 needs to have multiple connection terminals that connect to the ADC, which in turn connects to each sensor unit. Furthermore, offset noise may occur on the path from the sensor unit to the control unit 290.

[0159] Therefore, in this invention, digital data for differential signals can be acquired at the front-end terminal, and the acquired digital data can be input to the control unit 290.

[0160] In other words, in this invention, digital data can be acquired in the first position sensor unit 260 and the second position sensor unit 270, so only the acquired digital data can be input to the control unit 290.

[0161] The first position sensor unit 260 and the second position sensor unit 270 will be described in detail below.

[0162] Figure 9 It is shown Figure 8 A block diagram showing the detailed configuration of the position sensor unit.

[0163] Figure 9The components shown represent either the first position sensor unit 260 or the second position sensor unit 270. The first position sensor unit 260 and the second position sensor unit 270 may have the same configuration as each other and therefore may be connected to the control unit 290.

[0164] Reference Figure 9 Each of the first position sensor unit 260 and the second position sensor unit 270 includes a plurality of sensor units 310, an amplifier 320 and an analog-to-digital converter 330.

[0165] Sensor unit 310 includes a sensor for position detection. Preferably, sensor unit 310 may include multiple Hall sensors. Alternatively, sensor unit 310 may include multiple induction coils.

[0166] In sensor unit 310, the two outermost sensors are connected to amplifier 320, and the remaining sensor units are connected to adjacent sensor units. The connection structure of sensor unit 310 will be described in more detail below.

[0167] In other words, according to the invention described above, the sensor units 310 are connected to each other, and correspondingly, the output terminal of the outermost sensor unit is connected to the amplifier 320. Therefore, the sum of the detection signals detected by the sensor units is input to the amplifier 320, and this sum is represented as the sum of the sensing ranges of the sensor units. Thus, compared to a single sensor unit, the sensing range of the sensor units 310 input to the amplifier 320 is expanded.

[0168] Amplifier 320 includes a non-inverting terminal (+) and an inverting terminal (-). Furthermore, amplifier 320 differentially amplifies the signal input to the non-inverting terminal (+) and the signal input to the inverting terminal (-) and outputs them to analog-to-digital converter 330. In other words, the output signal of sensor unit 310 has a magnitude of several mV, which, considering the ratio, does not match the input range of analog-to-digital converter 330. Therefore, amplifier 320 differentially amplifies and outputs the signal input through the non-inverting terminal (+) and the inverting terminal (-) to match the input range of analog-to-digital converter 330.

[0169] The analog-to-digital converter 330 receives analog signals from the amplifier 320 and converts the received analog signals into digital signals accordingly and outputs them.

[0170] Preferably, the analog-to-digital converter 330 receives an analog signal from the amplifier 320 and outputs the received analog signal as a multi-bit digital signal. The output signal of the analog-to-digital converter 330 can be represented as values ​​of 0 and 1.

[0171] The sensor unit 310 according to the first embodiment of the present invention may be composed of a plurality of Hall sensors 310A.

[0172] In the following text, the interconnection of the Hall sensors will be described if the sensor unit 310 consists of Hall sensors.

[0173] Figures 10a to 10d It is used for explanation Figure 9 A view of the connection relationships of the sensor units.

[0174] Reference Figure 10a The Hall sensor constituting the sensor unit 310 includes four terminals. Two of the four terminals are input terminals, and the remaining two terminals are output terminals.

[0175] In addition, the two input terminals are power input terminals, and the two output terminals are detection signal output terminals.

[0176] Preferably, the Hall sensor includes a first power supply terminal 311, a second power supply terminal 312, a first detection signal output terminal 313, and a second detection signal output terminal 314. The first power supply terminal 311 is a terminal for inputting a positive power supply, and the second power supply terminal 312 is a terminal for inputting a negative power supply. The first detection signal output terminal 313 is a terminal for outputting a positive detection signal, and the second detection signal output terminal 314 is a terminal for outputting a negative detection signal.

[0177] The Hall sensor constituting the sensor unit 310 can indicate different connection relationships between two output terminals based on its arrangement position on the camera module.

[0178] In other words, each of the first power terminals 311 of the Hall sensor is connected to a positive power source, and the second power terminal 312 is connected to a negative power source (or ground).

[0179] Furthermore, depending on their placement, the detection signal output terminals of the Hall sensors can have different connection relationships. At least two Hall sensors are configured. In other words, the sensor unit comprises at least two sensor units.

[0180] The following describes the case where the sensor unit consists of three Hall sensors. When the sensor unit consists of three Hall sensors, two of the Hall sensors can be positioned on the outer edges, while the remaining Hall sensor can be arranged between the two outer Hall sensors. Furthermore, in the Hall sensor positioned between the two outer Hall sensors, the first detection signal output terminal 313 and the second detection signal output terminal 314 are respectively connected to the output terminals of the two outer Hall sensors. Additionally, in each of the two outer Hall sensors, one of the two output terminals is connected to amplifier 320, and the other output terminal is connected to the adjacent Hall sensor.

[0181] In other words, Figure 10b This diagram illustrates the connection relationship of the output terminals of the Hall sensor, which is the first component installed in a Hall sensor configuration. (Refer to...) Figure 10b The first Hall sensor initially configured includes a first detection signal output terminal 313 and a second detection signal output terminal 314. The first detection signal output terminal 313 is connected to the non-inverting terminal (+) of the amplifier 320, and the second detection signal output terminal 314 is connected to the first detection signal output terminal of an adjacent Hall sensor. In other words, the second detection signal output terminal 314 of the first Hall sensor is connected to the first detection signal output terminal of the second Hall sensor.

[0182] also, Figure 10c This diagram illustrates the connection relationship of the output terminals of the Hall sensors located between the Hall sensors on the outside. In other words, Figure 10c This diagram shows the connection relationships of the output terminals of the Hall sensors other than the first and last Hall sensors installed.

[0183] Reference Figure 10c The second Hall sensor, in addition to the first and last Hall sensors installed, includes a first detection signal output terminal 313 and a second detection signal output terminal 314. Furthermore, the first detection signal output terminal 313 of the second Hall sensor is connected to the second detection signal output terminal of the previously installed Hall sensor, and the second detection signal output terminal 314 is connected to the first detection signal output terminal of the subsequently installed Hall sensor. In other words, the first detection signal output terminal of the second installed Hall sensor is connected to the second detection signal output terminal of the first installed Hall sensor, and the second detection signal output terminal of the second installed Hall sensor is connected to the first detection signal output terminal of the third installed Hall sensor.

[0184] Figure 10dThe connection relationship of the output terminals of the last Hall sensor is shown. The last third Hall sensor includes a first detection signal output terminal 313 and a second detection signal output terminal 314. In addition, the first detection signal output terminal 313 of the third Hall sensor is connected to the second detection signal output terminal of the previously installed Hall sensor, and the second detection signal output terminal 314 is connected to the inverting terminal (-) of the amplifier 320.

[0185] As described above, according to the present invention, only one of the two output terminals of each of the two Hall sensors located on the outer side can be connected to the amplifier 320, while all the remaining terminals can be connected to the output terminals of the adjacent Hall sensors respectively. In the case of the above connection structure, a signal corresponding to the sum of the sensing ranges of the Hall sensors is input to the amplifier 320; therefore, the amplifier 320 differentially amplifies the input signal and outputs it.

[0186] In embodiments of the present invention, position sensors, such as multiple Hall sensors, can be connected to each other, so only the output terminal of the outermost position sensor can be connected to the amplifier. Therefore, in the present invention, the differential signal from the position sensor can be input to the input terminal of the amplifier.

[0187] According to the present invention, a differential sensing scheme can be provided, wherein the detection range is wider compared to a single sensing scheme. Furthermore, according to the present invention, the differential signal based on a combination of position sensors can be input to the input terminal of an amplifier, so that the offset noise exposed to the position sensor output signal on the path to the control unit can be minimized.

[0188] Furthermore, according to the present invention, a differential signal for the position sensor is output in the sensing unit, which includes a position sensor, an amplifier, and an analog-to-digital converter, thereby minimizing the number of patterns / pins connected from the driving unit to the printed circuit board, thus saving space on the printed circuit board.

[0189] Furthermore, according to the present invention, the differential value of the position sensor can be obtained relative to the common-mode noise, thereby achieving excellent characteristics not only against internal noise but also against external noise.

[0190] Furthermore, according to the present invention, depending on the usage environment of the camera module, only the detection signal from a specific position sensor can be sent to the amplifier terminals, or differential signals from multiple position sensors can be sent. According to the present invention, optimal detection signals can be acquired in environments requiring high sensing sensitivity and a large sensing range.

[0191] Figure 11This is a diagram comparing the connection relationship of the sensor unit according to the comparative example and the connection relationship of the sensor unit according to the present invention.

[0192] In other words, multiple position sensors can be arranged to widen the sensing range of the position sensors, so that the control unit 290 can calculate and use the differential signals of the position sensors.

[0193] In other words, such as Figure 11 As shown in (a), in the comparative example, the output terminals of multiple Hall sensors are connected to different amplifiers. Furthermore, the amplifiers connected to the Hall sensors are connected to different analog-to-digital converters (ADCs). Therefore, the control unit is required to have input pins connected to multiple ADCs. Each ADC outputs a multi-bit digital signal through multiple signal lines; therefore, as the number of ADCs increases, the number of input pins required by the control unit increases proportionally. Additionally, in the comparative example, the number of amplifiers and ADCs is required to be the same as the number of Hall sensors.

[0194] However, according to the present invention, one of the two output terminals of the Hall sensor located on the outside of the Hall sensor can be connected to the non-inverting terminal (+) and the inverting terminal (-) of the amplifier 320, while the remaining output terminals included in the Hall sensor can be connected to the output terminals of adjacent Hall sensors. According to the present invention, the number of input pins required for the control unit 290 can be minimized, and the exposure of the detection signal to offset noise in the path moving to the control unit 290 can be minimized.

[0195] Figure 12 This is a view used to illustrate the connection relationship of sensor units according to another embodiment of the present invention.

[0196] Each sensor unit has been described as consisting of a Hall sensor. However, according to the present invention, in addition to a Hall sensor, the sensor unit may consist of an induction coil.

[0197] refer to Figure 12 The sensor unit includes multiple induction coils. Additionally, each induction coil includes two output terminals. One of the two output terminals can be one end of the induction coil, and the other output terminal can be the other end of the induction coil.

[0198] In addition, the end of the induction coil can be connected to the end of an adjacent induction coil, or it can be connected to the non-inverting terminal (+) or inverting terminal (-) of the amplifier 320, so as to correspond to the connection relationship of the Hall sensor.

[0199] In other words, the first output terminal of the first set induction coil can be connected to the non-inverting terminal (+) of amplifier 320. Furthermore, the second output terminal of the first set induction coil can be connected to the first output terminal of the next adjacent induction coil.

[0200] In addition, the first output terminal of the second set induction coil can be connected to the second output terminal of the previously set induction coil, and the second output terminal of the second set induction coil can be connected to the first output terminal of the next induction coil.

[0201] In addition, the first output terminal of the last set induction coil can be connected to the second output terminal of the previously set induction coil, and the second output terminal of the last set induction coil can be connected to the inverting terminal (-) of the amplifier 320.

[0202] Figure 13 This is a view showing the detection range of the position sensor unit according to the comparative example. Figure 14 This is a view showing the detection range of a position sensor unit according to an embodiment of the present invention.

[0203] refer to Figure 13 When the sensor unit constituting the position sensor unit is a single sensor unit, the sensing range of the position sensor unit may be quite narrow. In other words, according to conventional sensing methods, only the output of one sensor is used, and only the linear portion (X portion) of the output of that single sensor is used.

[0204] The difference is, reference Figure 14 In this invention, the position sensor unit includes multiple sensor units; therefore, the sensing range is determined based on the differential signals of the sensor units. Thus, this invention can provide a position sensing unit with a sensing range greater than... Figure 13 The comparative example shown has a wide position sensing range.

[0205] Figure 15 This is a block diagram illustrating a detailed configuration of a position sensor unit according to another embodiment of the present invention.

[0206] Meanwhile, the position sensor unit, as described above, provides a signal to the amplifier 320 through a structure in which multiple sensor units are interconnected. In the above connection structure, the sensing range of the sensor unit's detection signal can be significantly increased; however, the sensing sensitivity may be reduced compared to a single sensor solution.

[0207] According to the present invention, depending on the operating conditions of the camera module, detection signals connected to multiple sensor units can be provided to the amplifier 320, or only the detection signals of a specific sensor unit among the sensor units can be sent to the amplifier 320.

[0208] Therefore, such as Figure 15 As shown, the position sensor unit also includes a switch 340.

[0209] One end of switch 340 is connected to the inverting terminal (-) of amplifier 320, and the other end is connected to any one of the output terminals of sensor unit.

[0210] In other words, when the sensor unit includes two Hall sensors, the switch 340 can be connected to the second detection signal output terminal of the first Hall sensor or to the second detection signal output terminal of the second Hall sensor.

[0211] When switch 340 is connected to the second detection signal output terminal of the first-set Hall sensor, only the output signal of the first-set Hall sensor is input to amplifier 320. According to the present invention, amplifier 320 is configured to connect only to a specific Hall sensor, so that optimal sensing sensitivity can be provided under conditions requiring sensing sensitivity.

[0212] Furthermore, when switch 340 is connected to the second detection signal output terminal of the second Hall sensor, a combined signal of the output signals from the first and second Hall sensors can be input to amplifier 320. According to the present invention, amplifier 320 is connected to the Hall sensor so that an optimal sensing range can be provided under the condition of required sensing range.

[0213] In embodiments of the invention, position sensors, such as multiple Hall sensors, can be connected to each other; therefore, only the output terminal of the outermost position sensor can be connected to the amplifier. According to the invention, the differential signal from the position sensor can be input to the input terminal of the amplifier.

[0214] According to the present invention, a differential sensing scheme can be provided, wherein the detection range is wider compared to a single sensing scheme. Furthermore, according to the present invention, the differential signal based on the combination of position sensors can be input to the input terminal of an amplifier, thereby minimizing the offset noise exposed to the position sensor output signal on the path to the control unit.

[0215] Furthermore, according to the present invention, a differential signal for the position sensor is output in the sensing unit, which includes a position sensor, an amplifier, and an analog-to-digital converter, thereby minimizing the number of patterns / pins connected from the driving unit to the printed circuit board, thus saving space on the printed circuit board.

[0216] Furthermore, according to the present invention, the differential value of the position sensor can be obtained relative to the common-mode noise, thereby achieving excellent characteristics not only against internal noise but also against external noise.

[0217] Furthermore, according to the present invention, depending on the usage environment of the camera module, only the detection signal from a specific position sensor can be sent to the amplifier terminals, or differential signals from multiple position sensors can be sent. According to the present invention, optimal detection signals can be acquired in environments requiring high sensing sensitivity and a large sensing range.

[0218] Figure 16 This is a flowchart for step-by-step explaining the operation method of the camera module according to an embodiment of the present invention.

[0219] First, the control unit 290 determines the position sensing conditions of the first and second lens assemblies of the camera module (step 110). When determining the position sensing conditions, it can be determined whether the current operating conditions require sensing sensitivity or sensing range to acquire position data. For example, when the lens assembly has a wide range of motion, a wide sensing range may be needed for accurate position detection. Conversely, when the lens assembly has a small range of motion and minute movements, accurate sensing sensitivity may be needed rather than a wide sensing range. Therefore, the control unit can determine the position sensing conditions.

[0220] Furthermore, the control unit 290 controls the switching operation of the switch 340 based on the determined position sensing conditions (step 120).

[0221] Then, the control unit 290 receives differential signals from multiple interconnected sensor units or detection signals from a specific sensor unit according to the operation of the switch 340 (step 130).

[0222] In addition, the control unit 290 can calculate the current position of the first lens assembly or the second lens assembly based on the received signal (step 140).

[0223] In addition, when calculating the current position, the control unit 290 outputs a control signal to the first lens drive unit 240 or the second lens drive unit 250 based on the difference between the calculated current position and the target position (step 150).

[0224] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment, but are not limited to one embodiment. Furthermore, those skilled in the art can combine or modify the features, structures, effects, etc., described in the embodiments to perform other embodiments. Therefore, content related to combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0225] Although exemplary embodiments have been presented and described in the foregoing description, the invention should not be construed as limited to these embodiments. It will be apparent to those skilled in the art that various modifications and variations, not shown, can be derived without departing from the inherent characteristics of the embodiments of the invention. For example, each element specifically shown in the embodiments can be modified. Furthermore, it will be apparent that differences relating to modifications and variations are included within the scope of the embodiments set forth in the appended claims.

Claims

1. A camera module, comprising: Fixed lens assembly; The movable lens assembly moves relative to the fixed lens assembly along the optical axis. A lens driving unit is configured to move the movable lens assembly along the optical axis direction; A position sensor unit is configured to detect the position of the movable lens assembly moving along the optical axis in the optical axis direction. The position sensor unit includes a first sensor unit, a second sensor unit, and a third sensor unit. The second sensor unit is disposed between the first sensor unit and the third sensor unit. The first, second, and third sensor units are arranged adjacent to each other to detect the position of the moving lens assembly in the optical axis direction and have outputs connected to each other. The first sensor unit includes a first detection signal output terminal and a second detection signal output terminal. The second sensor unit includes a third detection signal output terminal and a fourth detection signal output terminal. The third sensor unit includes a fifth detection signal output terminal and a sixth detection signal output terminal. The second detection signal output terminal and the third detection signal output terminal have different polarities and are directly connected to each other. The fourth detection signal output terminal and the fifth detection signal output terminal have different polarities and are directly connected to each other. The camera module further includes: An amplifier is connected to the first sensor unit, the second sensor unit, and the third sensor unit. The amplifier includes a first input terminal and a second input terminal. The first input terminal is directly connected to the first detection signal output terminal. The second input terminal is directly connected to the sixth detection signal output terminal, and The polarity of the first detection signal output terminal is different from that of the sixth detection signal output terminal.

2. The camera module according to claim 1, wherein, The lens driving unit includes a magnet disposed on the movable lens assembly and configured to move together with the movable lens assembly along the optical axis. The first sensor unit, the second sensor unit, and the third sensor unit detect the movement of the magnet in the direction of the optical axis.

3. The camera module according to claim 1, wherein, The first input terminal is one of a non-inverting terminal and an inverting terminal, and The second input terminal is the other one of the non-inverting terminal and the inverting terminal.

4. The camera module according to claim 1, wherein, The amplifier receives the differential signal of the first detection signal from the first sensor unit and the second detection signal from the third sensor unit. The lens driving unit further includes a magnet and a coil positioned facing the magnet. The current applied to the coil is controlled based on the differential signal.

5. The camera module of claim 1, further comprising an analog-to-digital converter connected to the amplifier.

6. The camera module according to claim 5, wherein, Each of the first sensor unit, the second sensor unit, and the third sensor unit includes a Hall sensor.

7. The camera module according to claim 6, further comprising: Prisms are configured to alter the optical path. The fixed lens assembly is disposed between the prism and the movable lens assembly.

8. The camera module according to claim 7, wherein, The movable lens assembly includes a first lens assembly and a second lens assembly. The fixed lens assembly includes a third lens assembly aligned with the first lens assembly and the second lens assembly along the optical axis. The lens driving unit includes a first lens driving unit and a second lens driving unit. The first lens driving unit is configured to move the first lens assembly along the optical axis, and the second lens driving unit is configured to move the second lens assembly along the optical axis. The position sensor unit includes a first position sensor unit and a second position sensor unit. The first position sensor unit is configured to detect the position of the first lens assembly moving along the optical axis in the optical axis direction. The second position sensor unit is configured to detect the position of the second lens assembly moving along the optical axis in the optical axis direction. The first position sensor unit and the second position sensor unit each include the first sensor unit, the second sensor unit and the third sensor unit.

9. The camera module according to claim 8, wherein, The first lens driving unit includes a first magnet, which is disposed on the first lens assembly and configured to move together with the first lens assembly along the optical axis. The second lens driving unit includes a second magnet, which is disposed on the second lens assembly and configured to move together with the second lens assembly along the optical axis. The first position sensor unit detects the movement of the first magnet along the optical axis, and The second position sensor unit detects the movement of the second magnet in the direction of the optical axis.

10. The camera module according to claim 9, wherein, The prism, the third lens assembly, the second lens assembly, and the first lens assembly are arranged sequentially along the optical axis. Wherein, the second lens assembly is a focusing lens assembly, and The first lens assembly is a zoom lens assembly.

Images