Camera module and its operating method

Abstract

To provide a camera module.SOLUTION: A camera module comprises: a lens assembly; a lens driving unit for moving the lens assembly in the direction of the optical axis; a position sensor unit for detecting the position of the lens assembly; and a control unit for, on the basis of the position of the lens assembly detected through the position sensor unit, outputting, to the lens driving unit, a drive signal for moving the lens assembly to a target position, where the position sensor unit comprises a plurality of sensor units which have at least one output terminal connected with each other, an amplifier which is commonly connected with the plurality of sensor units, and an analog-digital converter which is connected to the amplifier.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a camera module and an operation method thereof.

Background Art

[0002] A camera module performs a function of photographing a subject and storing it as an image or a video, and is mounted on a mobile terminal such as a mobile phone, a notebook computer, a drone, a vehicle, and the like.

[0003] On the other hand, a portable device such as a smartphone, a tablet PC, or a notebook computer incorporates an ultra-small camera module, and such a camera module can perform an auto focus (AF) function of automatically adjusting the distance between an image sensor and a lens to align the focal length of the lens.

[0004] The auto focus function is an essential function for clearly photographing a still image or a video within a camera module. The auto focus function uses a position sensor to detect the position of a lens barrel to which a magnet is attached, and provides a drive signal to a drive unit based on the detected position of the lens barrel and an input target position. Then, a driving force is generated between a coil of the drive unit and a magnet attached to the lens barrel, and the auto focus function is performed while the position of the lens barrel moves to a focal position. However, the position sensor provided to provide the auto focus function as described above provides a sensing signal including ambient noise and the like. For this reason, there is a disadvantage that the position of the lens barrel is not adjusted to an accurate position.

[0005] In addition, in the case of a camera module provided in a portable device, electromagnetic components are in close proximity to the components of the camera module, and thus have high-frequency noise characteristics. Therefore, a low-noise technology is essential. Also, in the case of a conventional position sensor, noise characteristics are improved by signal processing in the drive unit, but there is a limit to improving the noise characteristics only by signal processing. [Disclosure of the Invention] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a camera module and a method for operating this module that detects the position of a lens barrel based on the differential signals of multiple position sensors and increases the range of position detection.

[0007] Another object of the present invention is to provide a camera module and a method for operating the same that can obtain a difference value at the front-end stage of the sensing unit.

[0008] The present invention is not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which the proposed embodiments belong, as described below. [Means for solving the problem]

[0009] The camera module according to the present invention includes a lens assembly, a lens drive unit for moving the lens assembly in the optical axis direction, a position sensor unit for detecting the position of the lens assembly, and a control unit that outputs a drive signal to the lens drive unit for moving the lens assembly to a target position based on the position of the lens assembly detected via the position sensor unit, wherein the position sensor unit includes a plurality of sensor units each having at least one output terminal interconnected, an amplifier connected in common to the plurality of sensor units, and an analog-to-digital converter connected to the amplifier.

[0010] The amplifier includes an inverting terminal and a non-inverting terminal, the inverting terminal of the amplifier being connected to the first output terminal of the first sensor unit among the plurality of sensor units, and to the second output terminal of a second sensor unit different from the first sensor unit among the plurality of sensor units.

[0011] The first sensor unit is the first sensor unit to be placed among the plurality of sensor units, and the second sensor unit is the last sensor unit to be placed among the plurality of sensor units.

[0012] The first sensor unit is a first Hall sensor, the second sensor unit is a second Hall sensor, the first output terminal is the positive polarity output terminal of the first Hall sensor, and the second output terminal is the negative polarity output terminal of the second Hall sensor.

[0013] The negative output terminal of the first Hall sensor is connected to the positive output terminal of the second Hall sensor.

[0014] The first sensor unit is a first induction coil, the second sensor unit is a second coil, the first output terminal is one end of the first induction coil, the second output terminal is the other end of the second induction coil, and the other end of the first induction coil is connected to one end of the second induction coil.

[0015] Furthermore, the plurality of sensor units include a third Hall sensor positioned between the first and second Hall sensors, the positive output terminal of the third Hall sensor being connected to the negative output terminal of the first Hall sensor, and the negative output terminal of the third Hall sensor being connected to the positive output terminal of the second Hall sensor.

[0016] Furthermore, the system includes a switch, one end of which is connected to the inverting terminal of the amplifier, and the other end of which is selectively connected to either the negative polarity output terminal of the first Hall sensor or the negative polarity output terminal of the second Hall sensor.

[0017] The lens assembly includes a first lens assembly including a zoom lens group and a second lens assembly including a focus lens group, and the position sensor unit includes a first position sensor unit for detecting the position of the first lens assembly and a second position sensor unit for detecting the position of the second lens assembly.

[0018] Furthermore, the operation method of the camera module according to the present invention includes the steps of: determining the sensing conditions of the position sensor; controlling a switch according to the determined sensing conditions so that the inverting terminal of the amplifier is connected to either the output terminal of the first-positioned sensing unit or the output terminal of the last-positioned sensing unit among the plurality of sensing units; detecting the position of the lens assembly corresponding to the detection signal input to the amplifier by controlling the switch; and moving the lens assembly to the target position according to the detected position, wherein the detection step includes receiving the output signal of the first-positioned sensing unit as the inverting terminal is connected to the output terminal of the first-positioned sensing unit, and receiving differential signals from the combination of the plurality of sensing units as the inverting terminal is connected to the output terminal of the last-positioned sensing unit.

[0019] Furthermore, each of the plurality of sensing units includes a plurality of output terminals, and at least one of the plurality of output terminals of each sensing unit is connected to an output terminal of an adjacent sensing unit. [Effects of the Invention]

[0020] According to the present invention, multiple position sensors are interconnected so that only the output terminal of the outermost position sensor is connected to the amplifier. As a result, differential signals from the multiple position sensors are input to the input terminal of the amplifier.

[0021] According to this, in the present invention, it is possible to provide a differential sensing method in which the detection range is wider compared to a single sensing method. Also, in the present invention, by allowing a differential signal obtained by combining the plurality of position sensors to be input to the input terminal of the amplifier, it is possible to minimize the influence of offset noise in the path to the signal processing unit of the driving unit.

[0022] Further, in the present invention, within a sensing unit composed of a plurality of position sensors, an amplifier, and an analog-to-digital converter, a differential signal for the plurality of position sensors is output, so that in the driving unit, the patterns and the number of pins connected to the printed circuit board can be minimized, thereby saving the space of the printed circuit board.

[0023] Furthermore, in the present invention, by obtaining a difference value for the plurality of position sensors with respect to common-mode noise, it is possible to have excellent characteristics not only for internal noise but also for external noise.

[0024] Note that in the present invention, depending on the usage environment of the camera module, only the detection signal of a specific position sensor is transmitted to the amplifier stage, or a differential signal for the plurality of position sensors is transmitted. Thereby, in the present invention, an optimal detection signal can be obtained in an environment where the sensing sensitivity must be increased and in an environment where the detection range must be increased, respectively.

Brief Description of the Drawings

[0025] [Figure 1] It is a perspective view of a camera module according to the present invention. [Figure 2] It is a perspective view of the camera module in FIG. 1 with the lid removed. [Figure 3a] It is a perspective view of the mount in the camera module of FIG. 2. [Figure 3b] It is a perspective view of the camera module of FIG. 2 with the mount removed. [Figure 4a]Figure 2 is a perspective view of the first lens assembly in the camera module. [Figure 4b] Figure 2 is a perspective view of the second lens assembly in the camera module. [Figure 4c] Figure 2 is a perspective view of the second lens assembly in the camera module. [Figure 5a] Figure 3b is a conceptual diagram of the first magnetization method for the magnet in the camera module. [Figure 5b] Figure 3a is a conceptual diagram of the second magnetization method for the magnet in the camera module. [Figure 6] Figure 2 is a plan view of the camera module. [Figure 7a] This is a cross-sectional view of the camera module along the line A1-A1' in Figure 6. [Figure 7b] This is a cross-sectional view of the camera module along the line A2-A2' in Figure 6. [Figure 7c] This is a cross-sectional view of the camera module along the line A3-A3' in Figure 6. [Figure 8] This is a block diagram showing the internal configuration of the camera module according to the present invention. [Figure 9] Figure 8 is a block diagram showing the detailed configuration of the position sensor unit. [Figure 10a] This diagram illustrates the connection relationships of the sensor unit in Figure 9. [Figure 10b] This diagram illustrates the connection relationships of the sensor unit in Figure 9. [Figure 10c] This diagram illustrates the connection relationships of the sensor unit in Figure 9. [Figure 10d] This diagram illustrates the connection relationships of the sensor unit in Figure 9. [Figure 11] This diagram compares the connection relationships between a sensor unit using a comparative example and the sensor unit of the present invention. [Figure 12] This diagram illustrates the connection relationships of a sensor unit according to another embodiment of the present invention. [Figure 13]This figure shows the detection range of the position sensor unit in a comparative example. [Figure 14] This figure shows the detection range of the position sensor unit according to an embodiment of the present invention. [Figure 15] This is a block diagram showing the detailed configuration of a position sensor unit according to another embodiment of the present invention. [Figure 16] This is a flowchart illustrating, step by step, the operation method of the camera module according to an embodiment of the present invention. [Modes for carrying out the invention]

[0026] The following will be explained in detail with reference to the attached diagrams.

[0027] On the other hand, when describing the embodiments, if we state that something is formed "above / below" each element, "above / below" includes both cases where two elements are in direct contact with each other, or where one or more other elements are positioned indirectly between the two elements. Furthermore, when expressed as "above / below," it can include not only the upward direction but also the downward direction, based on one element.

[0028] Furthermore, relational terms such as "upper / top" and "lower / bottom" used below do not require or imply any physical or logical relationship or order between such components or elements, but are used to distinguish one component or element from another.

[0029] Furthermore, in the description of the embodiments, terms such as "first," "second," etc., are used to describe various components, but these terms are used for the purpose of distinguishing one component from others. In addition, terms specifically defined in consideration of the configuration and operation of the embodiments are merely for the purpose of describing the embodiments and do not limit the scope of the embodiments.

[0030] Figure 1 is a perspective view of the camera module 100 according to the present invention, and Figure 2 is a perspective view of the camera module 100 in Figure 1 with the cover 10 removed.

[0031] First, referring to Figure 1, the camera module 100 according to the present invention has various optical systems coupled on a predetermined mount 20 (see Figure 2). For example, a prism 140 and a lens group are arranged on the mount 20, and a cover 10 is coupled to it via a hook 20H of the mount 20.

[0032] The cover 10 is coupled to the mount 20. The cover 10 covers the components housed in the mount 20, thereby protecting the components of the camera module. The mount 20 is also referred to as the base.

[0033] The lid 10 is joined to the mount 20 by fitting. The lid 10 is also joined to the mount 20 by adhesive. For example, a hook 20H is provided on the side of the mount 20, and a hole is formed in the lid 10 at a position corresponding to the hook (H). The hook of the mount 20 is inserted into the hole in the lid 10, thereby joining the lid 10 and the mount 20. The lid 10 is also stably joined to the mount 20 using adhesive.

[0034] Furthermore, a circuit board 107 is positioned below the mount 20. The circuit board 107 is electrically connected to the lens drive unit located inside the mount 20.

[0035] Next, as shown in Figure 2, the camera module 100 according to the present invention has an optical system and a lens drive unit arranged on the mount 20. For example, the camera module 100 includes at least one of the following: a first lens assembly 110, a second lens assembly 120, a third lens group 130, a prism 140, a first drive unit 310, a second drive unit 320, a rod 50, and an image sensor unit 210.

[0036] The first lens assembly 110, the second lens assembly 120, the third lens group 130, the prism 140, the image sensor unit 210, etc., are classified as an optical system.

[0037] Furthermore, the first drive unit 310, the second drive unit 320, the rod 50, etc., are classified as lens drive units, and the first lens assembly 110 and the second lens assembly 120 can also function as lens drive units. The first drive unit 310 and the second drive unit 320 are coil drive units, but are not limited to this.

[0038] The rods 50 serve as guides for the moving lens assembly and may be provided in one or more configurations. For example, the rods 50 may include, but are not limited to, a first rod 51 and a second rod 52.

[0039] In the axial directions shown in Figure 2, the Z-axis represents the optical axis direction or a direction parallel to it. The Y-axis represents the direction perpendicular to the Z-axis in the plane of the paper (YZ plane). The X-axis represents the direction perpendicular to the plane of the paper.

[0040] In the present invention, the prism 140 converts the incident light into parallel light. For example, the prism 140 converts the 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. Thereafter, the parallel light passes through the third lens group 130, the first lens assembly 110, and the second lens assembly 120, and enters the image sensor unit 210 to capture an image.

[0041] In the following description of the present invention, the moving lens group will be described as being in two cases, but it is not limited to these cases, and the moving lens group may be three, four, or five or more. Furthermore, the optical axis direction (Z) means the same direction as or parallel to the alignment direction of the lens group.

[0042] The camera module according to the present invention can perform a zooming function. For example, the first lens assembly 110 and the second lens assembly 120 are movable lenses that move via the first drive unit 310, the second drive unit 320, and the rod 50, and the third lens group 130 is a fixed lens.

[0043] For example, the first lens assembly 110 and the second lens assembly 120 include movable lens groups, and the third lens group 130 includes fixed lens groups.

[0044] The third lens group 130 functions as a focator, focusing parallel light at a specific position.

[0045] Furthermore, the first lens assembly 110 functions as a variator, re-imaging the image formed by the third lens group 130, which is a condenser, at another location. On the other hand, in the first lens assembly 110, the distance to the subject or the image distance changes frequently, resulting in a large change in magnification. As a variator, the first lens assembly 110 plays an important role in the change of focal length or magnification of the optical system.

[0046] On the other hand, the image point formed by the first lens assembly 110, which is a magnifier, may vary slightly depending on its position.

[0047] As a result, the second lens assembly 120 performs a position compensation function for the image formed by the magnifier. For example, the second lens assembly 120 functions as a compensator, which is responsible for correctly positioning the image point formed by the first lens assembly 110, which is the magnifier, at the actual position of the image sensor unit 210.

[0048] For example, the first lens assembly 110 is a zoom lens assembly that performs a zooming function, and the second lens assembly 120 is a focus lens assembly that performs a focusing function.

[0049] The features of the camera module according to the embodiment will be described in detail below with reference to Figures 3a to 5d.

[0050] First, Figure 3a is a perspective view of the mount 20 in the camera module of Figure 2. The mount 20 has a cuboid shape and includes four sides and a bottom surface 20e. For example, the mount 20 includes first to fourth sides 20a, 20b, 20c, and 20d, with the first side 20a and the second side 20b, and the third side 20c and the fourth side 20d facing each other. A hook 20H is provided on at least one side of the mount 20 and is connected to a hole in the lid 10.

[0051] Furthermore, a first guide groove 112G is provided on the bottom surface 20e of the mount 20, in the direction of the optical axis (Z), where the first lens assembly 110, the second lens assembly 120, and the third lens group 130 are located. The first guide groove 112G is recessed downward along the outer circumference of the lens, but is not limited to this shape.

[0052] Furthermore, the first side surface 20a and the second side surface 20b of the mount 20 are provided with a first opening 23a and a second opening 23b, where the first drive unit 310 and the second drive unit 320 are respectively arranged. Additionally, the third side surface 20c of the mount 20 is provided with a third opening 22, where the image sensor unit 210 is arranged.

[0053] Furthermore, one or more fourth openings 27 are provided on the bottom surface of the mount 20, through which the circuit board 107 is exposed.

[0054] Furthermore, one or more coupling holes 25 are provided on the third side surface 20c and the fourth side surface 20d opposite to it of the mount 20, to which the rods 50 are connected. For example, the third side surface 20c and the fourth side surface 20d of the mount 20 are provided with a first coupling hole 25a, a second coupling hole 25b, a third coupling hole 25c, and a fourth coupling hole 25d, to which the first rod 51, the second rod 52, the third rod 53, and the fourth rod 54 are connected, respectively.

[0055] Furthermore, a prism mounting portion 24 for positioning the prism 140 is provided on the inside of the fourth side surface 20d of the mount 20.

[0056] The material of the mount 20 is made of one or more of the following: plastic, glass-based epoxy, polycarbonate, metal, or composite material.

[0057] Next, Figure 3b is a perspective view of the camera module from Figure 2 with the mount 20 removed, showing the optical system and lens drive unit.

[0058] In the present invention, the lens drive device includes a mover and a fixed part. The mover is a concept corresponding to the fixed part and is also called the moving part. For example, the mover refers to a lens assembly that is moved by the rolling motion of a wheel. In contrast, the fixed part refers to a mount, rod, etc., that does not move.

[0059] The camera module according to the present invention includes an optical system on a mount 20, including a prism 140, a first lens assembly 110, a second lens assembly 120, a third lens group 130, and an image sensor unit 210. The camera module also includes lens drive units such as a first drive unit 310, a second drive unit 320, and a rod 50. The first lens assembly 110 and the second lens assembly 120 can also perform lens drive functions.

[0060] The rod 50 includes a first rod to a fourth rod 51, 52, 53, and 54, each of which is connected to a first coupling hole to a fourth coupling hole 25a, 25b, 25c, and 25d (see Figure 3a), and serves as a movement guide for the first lens assembly 110 and the second lens assembly 120. The rod 50 is made of one or more of the following materials: plastic, glass-based epoxy, polycarbonate, metal, or composite material.

[0061] The first drive unit 310 is a coil drive unit, and has a shape in which a first coil 314 is wound around a first core 312, such as an iron core. Similarly, the second drive unit 320 is a coil drive unit in which a second coil 324 is wound around a second core 322, such as an iron core.

[0062] First, the prism 140 changes the optical path of the incident light to an optical axis parallel to the central axis (Z) of the lens group, thereby changing the incident light into parallel light. Thereafter, the parallel light passes through the third lens group 130, the first lens assembly 110, and the second lens assembly 120, and is captured by the image sensor unit 210.

[0063] The prism 140 is an optical element having a triangular prism shape. Alternatively, a reflector or mirror can be used instead of the prism 140.

[0064] Furthermore, if the image sensor unit 210 is not positioned perpendicular to the optical axis, the light that has passed through the lens group is imaged by the image sensor unit 210, so a prism (not shown) may be further provided.

[0065] In the present invention, the image sensor unit 210 is arranged perpendicular to the optical axis direction of parallel light. The image sensor unit 210 includes a solid-state image sensor 214 arranged on a second circuit board 212. For example, the image sensor unit 210 includes a CCD (Charge Coupled Device) image sensor and a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor.

[0066] The first lens assembly 110 and the second lens assembly 120 will be described in detail with reference to Figures 4a and 4b.

[0067] Figure 4a is a perspective view of the first lens assembly 110 in the camera module of Figure 2, and Figure 4b is a perspective view of the second lens assembly 120 in the camera module of Figure 2.

[0068] As shown in Figure 4a, the first lens assembly 110 includes one or more of the following: the first housing 112, the first lens group 114, the first ring 117, the third drive unit 116, and the first position sensor 118.

[0069] Furthermore, as shown in Figure 4b, the second lens assembly 120 includes one or more of the following: the second housing 122, the second lens group 124, the second ring 127, the fourth drive unit 126, and the second position sensor 128.

[0070] The following description will focus on the first lens assembly 110.

[0071] The first housing 112 of the first lens assembly 110 includes a first lens housing 112a and a first drive unit housing 112b. The first lens housing 112a functions as a lens barrel and is fitted with a first lens group 114. The first lens group 114 is a movable lens group and may include one or more lenses. The second housing 122 of the second lens assembly 120 also includes a second lens housing 122a and a second drive unit housing 122b.

[0072] Here, a first guide groove 112G is provided on the underside of one end of the first lens housing 112a of the first lens assembly 110. Guided by the first guide groove 112G, the first lens assembly 110 moves linearly in the optical axis direction while sliding in contact with the second rod 52. A second guide groove 122G is also provided on the underside of one end of the second lens housing 122a of the second lens assembly 120.

[0073] Furthermore, the sliding contact between the second rod 52 and the first guide groove 112G causes the first housing 112 to move in the optical axis direction, thus enabling the realization of a camera module that performs efficient autofocusing and zooming functions.

[0074] Furthermore, the sliding contact between the first rod 51 and the second guide groove 122G causes the second housing 122 to move in the optical axis direction, thus enabling the realization of a camera module that performs efficient autofocusing and zooming functions.

[0075] Next, the first drive unit housing 112b of the first lens assembly 110 houses a third drive unit 116, a first wheel 117, and a first position sensor 118. The first wheel 117 includes a plurality of wheels, including a first-first wheel 117a and a first-second wheel 117b.

[0076] Furthermore, a fourth drive unit 126, a second wheel 127, and a second position sensor 128 are arranged in the second drive unit housing 122b of the second lens assembly 120. The second wheel 127 includes a plurality of wheels, including a second-first wheel 127a and a second-second wheel 127b.

[0077] The third drive unit 116 of the first lens assembly 110 is a magnetic drive unit, but is not limited thereto. For example, the third drive unit 116 may include a first magnet which is a permanent magnet. Similarly, the fourth drive unit 126 of the second lens assembly 120 is also a magnetic drive unit, but is not limited thereto.

[0078] For example, Figure 5a is a conceptual diagram of a first magnetization method for the first magnet in the third drive unit 116 of the first lens assembly 110, where the north pole of the permanent magnet is positioned opposite the first drive unit 310, and the south pole is located on the opposite side of the first drive unit 310.

[0079] In this case, according to Fleming's left-hand rule, the direction of the electromagnetic force becomes horizontal to the optical axis, and the first lens assembly 110 is driven.

[0080] In particular, in the present invention, as shown in Figure 4a, the first lens assembly 110 is provided with a first wheel 117, which is a rolling drive unit, and moves on the rod 50, thereby minimizing the generation of frictional torque.

[0081] As a result, the lens assembly, lens drive device, and camera module including the same according to the present invention can minimize the generation of frictional torque between the lens assembly and the guide rod that move during zooming, thereby improving the driving force. Therefore, according to the present invention, power consumption can be reduced and control characteristics can be improved when zooming the camera module.

[0082] On the other hand, Figure 5b is a conceptual diagram of a second magnetization method for the magnet, which is the first drive unit 116B, in the camera module according to the present invention.

[0083] In Figure 5a, the first drive unit 310 has a shape in which the first coil 314 is wound around a bar-shaped first core 312 (see Figure 3b). In contrast, the first-second drive unit 310B shown in Figure 5b has a shape in which the coil is wound around a donut-shaped core.

[0084] As a result, in the first drive unit 310 in Figure 5a, the direction of the current in the region facing the third drive unit 116 is unidirectional.

[0085] On the other hand, the direction of the current in the region of the first-second drive unit 310B in Figure 5b that faces the third drive unit 116 is not the same. For this reason, both the north and south poles of the permanent magnet, which is the third-second drive unit 116B, are positioned facing the first-second drive unit 310B.

[0086] Referring again to Figure 4a, the first drive unit housing 112b of the first lens assembly has a first position sensor 118 positioned therein, which enables position sensing and position control of the first lens assembly 110. For example, the first position sensor 118 positioned in the first drive unit housing 112b is positioned opposite a first sensing magnet (not shown) located on the bottom surface of the mount 20.

[0087] Furthermore, as shown in Figure 4b, by also arranging the second position sensor 128 in the second drive unit housing 122b of the second lens assembly, the position of the second lens assembly 120 can be sensed and its position controlled.

[0088] Next, Figure 6 is a plan view of the camera module in Figure 2. Furthermore, Figure 7a is a cross-section of the camera module in Figure 6 along the line A1-A1', viewed from the Y-axis direction. Furthermore, Figure 7b is a cross-section of the camera module in Figure 6 along the line A2-A2', viewed from the Z-axis direction. Furthermore, Figure 7c is a cross-section of the camera module in Figure 6 along the line A3-A3', viewed from the Z-axis direction.

[0089] First, in Figure 7a, the second drive unit housing 122 and the fourth drive unit 126 of the second lens assembly 120 are not cut apart.

[0090] As shown in Figure 7a, the first lens group 114 is mounted on the first lens housing 112a of the first lens assembly 110. The first lens group 114 is mounted on the first lens barrel 114b.

[0091] Furthermore, the second lens group 124 is mounted on the second lens housing 122a of the second lens assembly 120. The second lens group 124 is mounted on the second lens barrel 124b.

[0092] Furthermore, the third lens group 130 includes a third lens 134 mounted on the third lens barrel 1132.

[0093] Each of the first to third lens groups 114, 124, and 134 may contain one or more lenses.

[0094] In the camera module according to the present invention, the centers of the prism 140, the third lens group 130, the first lens group 114, and the second lens group 124 are aligned in the direction of the optical axis (Z).

[0095] The third lens group 130 is positioned opposite the prism 140, and light emitted from the prism 140 is incident on it.

[0096] At least one of the first to third lens groups 114, 124, and 134 is a fixed lens. For example, the third lens group 130 is fixedly positioned on the camera module and does not move in the optical axis direction, but is not limited to this.

[0097] For example, the mount 20 includes a mounting portion (not shown) to which the third lens group 130 is fixedly connected. The third lens group 130 is attached to the mounting portion and fixed to the mounting portion with an adhesive.

[0098] The second lens group 124 is positioned separately from the third lens group 130 in the optical axis direction and moves in the optical axis direction. The third lens group 130 is positioned separately from the second lens group 124 in the optical axis direction and moves in the optical axis direction.

[0099] The light emitted from the third lens group 130 is incident on the image sensor unit 210, which is located behind the third lens group 130.

[0100] As the first lens group 114 and the second lens group 124 move in the optical axis direction, 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 are adjusted, thereby enabling the camera module to zoom.

[0101] Next, Figure 7b is a view of a cross-section of the camera module along the line A2-A2' in Figure 6, as seen from the Z-axis direction, showing the first lens assembly 110 with the 1-1 ring 117a and the 1-3 ring 117c cut off, and the second lens assembly 120 with the 2-1 ring 127a and the 2-3 ring 127c cut off.

[0102] In the present invention, the first lens assembly 110 is equipped with a first-first wheel 117a and a first-third wheel 117c, which are rolling drive units, and the second lens assembly 120 is also equipped with a second-first wheel 127a and a second-third wheel 127c, which are rolling drive units. By rolling on the first rod 51, the third rod 53, the second rod 52, and the fourth rod 54, respectively, by electromagnetic force, the generation of frictional torque can be minimized.

[0103] As a result, the lens assembly, lens drive device, and camera module including the same according to the present invention can minimize the generation of frictional torque between the wheel, which is the rolling drive unit of the lens assembly that moves in the optical axis (Z) direction, and the guide rod 50 during zooming, thereby improving the driving force. Furthermore, according to the present invention, by minimizing the generation of frictional resistance between the wheel and rod 50 of the lens assembly, power consumption can be reduced and control characteristics can be improved during zooming of the camera module.

[0104] Next, Figure 7c is a view of a cross-section of the camera module in Figure 6 along the line A3-A3', as seen from the Z-axis direction, showing the first lens assembly 110 with the first-to-second rings 117b and the first-to-fourth rings 117d cut off, and the second lens assembly 120 with the second-to-second ring 127b, the second-to-fourth rings 127d, the second lens housing 122a, and the second lens group 124 cut off.

[0105] In the present invention, the first lens assembly 110 is equipped with first-second wheels 117b and first-fourth wheels 117d, which are rolling drive units, and the second lens assembly 120 is also equipped with second-second wheel 127b and second-fourth wheel 127d, which are rolling drive units. By rolling on the first rod 51, third rod 53, second rod 52, and fourth rod 54, respectively, the generation of friction torque can be minimized.

[0106] As a result, according to the present invention, the generation of friction torque between the ring of the lens assembly and the rod 50 can be minimized during zooming, thereby improving the driving force, reducing power consumption, and improving control characteristics, resulting in a combination of effects.

[0107] Figure 8 is a block diagram showing the internal configuration of the camera module of the present invention.

[0108] As shown in Figure 8, the camera module includes an image sensor 210, an image signal processing unit 220, a display unit 230, a first lens drive unit 240, a second lens drive unit 250, a first position sensor unit 260, a second position sensor unit 270, a storage unit 280, and a control unit 290.

[0109] As described above, the image sensor 210 processes the optical image of the subject focused on the lens. Therefore, the image sensor 210 can pre-process the image obtained through the lens. Furthermore, the image sensor 210 can convert the pre-processed image into electrical data and output it.

[0110] The image sensor 210 is a configuration in which numerous photodetectors are integrated as individual pixels, and it converts image information of the subject into electrical data for output. The image sensor 210 stores the amount of light input and outputs the image captured by the lens in accordance with the vertical synchronization signal based on the amount of light stored. Here, image acquisition is performed by the image sensor 210, which converts the light reflected from the subject into an electrical signal. On the other hand, in order to obtain a color image using the image sensor 210, a color filter is required, for example, a CFA (Color Filter Array) filter is used. A CFA has a structure in which only one color representing one color per pixel passes through and is arranged regularly, and it has various forms depending on the arrangement structure.

[0111] The image signal processing unit 220 processes the image output via the image sensor 210 on a frame-by-frame basis. Here, the image signal processing unit 220 is also referred to as an ISP (Image Signal Processor).

[0112] Here, the image signal processing unit 220 includes a lens shading compensation unit (not shown). The lens shading compensation unit is a block for compensating for the lens shading phenomenon, which appears differently in the light intensity of the central and edge regions of the image. It receives a lens shading setting value from the control unit 270 (described later) and compensates for the color differences between the central and edge regions of the image.

[0113] Furthermore, the lens shading compensation unit can receive shading variables set differently depending on the type of illumination and process the lens shading of the image in accordance with the received variables. This allows the lens shading compensation unit to apply different degrees of shading depending on the type of illumination and perform lens shading processing. On the other hand, in order to prevent saturation from occurring in the image, the lens shading compensation unit can also receive shading variables set differently depending on the automatic exposure weighting value applied to a specific area of ​​the image and process the lens shading of the image in accordance with the received variables. More specifically, the lens shading compensation unit compensates for brightness changes that occur in the edge region of the video signal by applying the automatic exposure weighting value to the central region of the video signal. That is, when saturation of the video signal occurs due to illumination, the intensity of light decreases concentrically from the center to the edges, so the lens shading compensation unit amplifies the edge signal of the video signal to compensate for the brightness compared to the center.

[0114] On the other hand, the image signal processing unit 220 can measure the sharpness of the image acquired via the image sensor 210. That is, the image signal processing unit 220 measures the sharpness of the image in order to check the focus accuracy of the image acquired via the image sensor 210. The sharpness can be measured for each image acquired at different positions of the focus lens.

[0115] The display unit 230 displays images captured under the control of the control unit 290, which will be described later, and displays necessary setting screens and screens for the user to select actions when taking a photograph.

[0116] The first lens drive unit 240 moves the first lens assembly. Preferably, the first lens drive unit 240 moves the first lens group included in the first lens assembly. Preferably, the first lens group is a zoom lens. The first lens drive unit 240 then moves the zoom lens in the optical axis direction to adjust the zoom position (or zoom magnification) of the zoom lens.

[0117] The second lens drive unit 250 moves the second lens assembly. Preferably, the second lens drive unit 250 moves the second lens group included in the second lens assembly as described above, where the second lens group includes a focusing lens. The second lens drive unit 250 then moves the focusing lens in the optical axis direction to adjust the focus position of the focusing lens.

[0118] The first position sensor unit 260 includes the first position sensor 118 described above, thereby detecting the position of the first lens assembly 110. Preferably, the first position sensor unit 260 can sense the position of the third drive unit 116 located on the first lens assembly 110. Preferably, the first position sensor unit 260 senses the position of the first lens assembly 110 in order to control its position.

[0119] 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.

[0120] The second position sensor unit 270 includes the aforementioned second position sensor 128, thereby detecting the position of the second lens assembly 120. Preferably, the second position sensor unit 270 can sense the position of the fourth drive unit 126 located on the second lens assembly 120. Preferably, the second position sensor unit 270 senses the position of the second lens assembly 120 in order to control its position.

[0121] In other words, the second position sensor unit 270 provides position data via the second lens drive unit 250 to move the second lens assembly.

[0122] The storage unit 280 stores data necessary for the operation of the camera module 100. In particular, the storage unit 280 stores information regarding the zoom position and focus position according to the distance to the subject. That is, the focus position is the position of the focus lens for correctly focusing on the subject. The focus position changes depending on the zoom position relative to the zoom lens and the distance to the subject. Therefore, the storage unit 280 stores data regarding the zoom position and the focus position corresponding to the zoom position, according to the distance.

[0123] The control unit 290 controls the overall operation of the camera module. In particular, the control unit 290 controls the first position sensor unit 260 and the second position sensor unit 270 in order to provide an autofocus function.

[0124] In other words, the control unit 290 enables the detection of the position of the first lens assembly via the first position sensor unit 260. Preferably, the control unit 290 enables the detection of the current position of the first lens assembly via the first position sensor unit 260 in order to move the first lens assembly to a target position.

[0125] Then, when the control unit 290 detects the current position of the first lens assembly via the first position sensor unit 260, it supplies a control signal to the first lens drive unit 240 to move the first lens assembly to a target position based on the current position of the first lens assembly.

[0126] Furthermore, the control unit 290 is configured to detect the position of the second lens assembly via the second position sensor unit 270. Preferably, the control unit 290 is configured to detect the current position of the second lens assembly via the second position sensor unit 270 in order to move the second lens assembly to a target position.

[0127] Then, when the control unit 290 detects the current position of the second lens assembly via the second position sensor unit 270, it supplies a control signal to the second lens drive unit 240 to move the second lens assembly to a target position based on the current position of the second lens assembly.

[0128] Here, the control unit 290 receives the differential signals of the detection signals detected by the multiple sensor units constituting each of the first and second position sensor units 260 and 270, respectively.

[0129] In other words, in the present invention, each of the first position sensor unit 260 and the second position sensor unit 270 includes a plurality of sensor units. The plurality of sensor units perform detection operations at their respective installation locations. In the present invention, the positions of the first lens assembly and the second lens assembly are detected, respectively, using the differential signals of the detection signals obtained through the plurality of sensor units.

[0130] In general, the control unit 290 receives signals detected by the plurality of sensor units, and based on the differential signals from these signals, the positions of the first lens assembly and the second lens assembly can be detected.

[0131] However, in the case of the structure described above, an amplifier and an analog-to-digital converter must be provided in each of the sensor units. Furthermore, the control unit 290 must be equipped with numerous connection terminals that are connected to the analog-to-digital converters connected to each sensor unit. In addition, there is the inconvenience of offset noise occurring along the path from each of the sensor units to the control unit 290.

[0132] Therefore, in the present invention, digital data for the differential signal is acquired in the front-end stage, and the acquired digital data is input to the control unit 290.

[0133] In other words, in the present invention, the first position sensor unit 260 and the second position sensor unit 270 are configured to acquire the digital data, and as a result, only the acquired digital data is input to the control unit 290.

[0134] The first position sensor unit 260 and the second position sensor unit 270 will be described in detail below.

[0135] Figure 9 is a block diagram showing the detailed configuration of the position sensor unit in Figure 8.

[0136] The components in Figure 9 show one of the position sensor units, either the first position sensor unit 260 or the second position sensor unit 270. Here, the first position sensor unit 260 and the second position sensor unit 270 may have the same configuration as each other, and thus can be connected to the control unit 290, respectively.

[0137] As shown in Figure 9, the first position sensor unit 260 and the second position sensor unit 270 each include a plurality of sensor units 310, an amplifier 320, and an analog-to-digital converter 330.

[0138] The plurality of sensor units 310 include sensors for position detection. Preferably, the plurality of sensor units 310 include a plurality of Hall sensors. Alternatively, the plurality of sensor units 310 include a plurality of induction coils.

[0139] Here, the two outermost sensors of the plurality of sensor units 310 are connected to the amplifier 320, and the remaining sensor units are connected to adjacent sensor units. The connection structure of the plurality of sensor units 310 will be described later.

[0140] In other words, as described above, in the present invention, the plurality of sensor units 310 are interconnected, thereby connecting the output terminal of the outermost sensor unit to the amplifier 320. As a result, the amplifier 320 receives a signal that is the sum of the detection signals detected by each of the sensor units. This is expressed as the sum of the sensing ranges of each of the sensor units, and therefore the sensing range for the plurality of sensor units 310 input to the amplifier 320 is extended compared to a single sensor unit.

[0141] The amplifier 320 includes a non-inverting terminal (+) and an inverting terminal (-). The amplifier 320 differentially amplifies the signal input at the non-inverting terminal (+) and the signal input at the inverting terminal (-) and outputs them to the analog-to-digital converter 330. In other words, the output signals to the multiple sensor units 310 have a size of several mV, which is a size that does not match the input range of the analog-to-digital converter 330. Therefore, the amplifier 320 differentially amplifies the signals input via the non-inverting terminal (+) and the inverting terminal (-) and outputs them to match the input range of the analog-to-digital converter 330.

[0142] The analog-to-digital converter 330 receives an analog signal from the amplifier 320 and converts the received analog signal into a digital signal for output.

[0143] Preferably, the analog-to-digital converter 330 receives an analog signal from the amplifier 320 and outputs it as a multi-bit digital signal. Here, the output signal of the analog-to-digital converter 330 is represented as values ​​of 0 and 1.

[0144] Here, the plurality of sensor units 310 in the first aspect of the present invention are composed of a plurality of Hall sensors 310A.

[0145] In the following section, we will describe the interconnection relationships of each Hall sensor when the multiple sensor units 310 consist of Hall sensors.

[0146] Figures 10a to 10d are diagrams illustrating the connection relationships of the sensor unit in Figure 9.

[0147] As shown in Figure 10a, the Hall sensors constituting the plurality of sensor units 310 include four terminals. Of these four terminals, two are input terminals and the remaining two are output terminals.

[0148] The two input terminals are power input terminals, and the two output terminals are detection signal output terminals.

[0149] Preferably, the Hall sensor includes a first power terminal 311, a second power terminal 312, a first detection signal output terminal 313, and a second detection signal output terminal 314. The first power terminal 311 is a terminal to which a positive (+) polarity power supply is input, and the second power terminal 312 is a terminal to which a negative (-) polarity power supply is input. The first detection signal output terminal 313 is a terminal to which a positive polarity detection signal is output, and the second detection signal output terminal 314 is a terminal to which a negative polarity detection signal is output.

[0150] Here, the connection relationship between the two output terminals of the multiple Hall sensors constituting the multiple sensor units 310 appears different depending on their position on the camera module.

[0151] In other words, the first power terminal 311 of each of the plurality of Hall sensors is connected to a positive polarity power supply, and the second power terminal 312 is connected to a negative polarity power supply (or ground).

[0152] Furthermore, the detection signal output terminals of each of the plurality of Hall sensors can have different connection relationships with each other depending on their arrangement. Here, the plurality of Hall sensors consist of at least two or more. In other words, the plurality of sensor units include at least two sensor units.

[0153] Here, we will describe the case where the plurality of sensor units consist of three Hall sensors. In the case where the plurality of sensor units consist of three Hall sensors, two of the Hall sensors are arranged in an outer casing, and the remaining one Hall sensor is arranged between the two Hall sensors arranged in the outer casing. In the one Hall sensor between the two Hall sensors arranged in the outer casing, the first detection signal output terminal 313 and the second detection signal output terminal 314 are connected to the output terminals of the two Hall sensors arranged in the outer casing, respectively. In each of the two Hall sensors arranged in the outer casing, one output terminal is connected to the amplifier 320, and the other output terminal is connected to the adjacent Hall sensor.

[0154] In other words, Figure 10b shows the connection relationship of the output terminals of the first Hall sensor among the multiple Hall sensors. As shown in Figure 10b, the first Hall sensor, which is the first to be placed, includes a first detection signal output terminal 313 and a second detection signal output terminal 314, where 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 the adjacent Hall sensor. In other words, the second detection signal output terminal 314 of the first Hall sensor, which is the first to be placed, is connected to the first detection signal output terminal of the second Hall sensor.

[0155] Furthermore, Figure 10c shows the connection relationships of the output terminals of Hall sensors placed between multiple Hall sensors arranged on the outer casing. In other words, Figure 10c shows the connection relationships of the output terminals of the remaining Hall sensors, excluding the first Hall sensor placed and the last Hall sensor placed.

[0156] As shown in Figure 10c, of the plurality of Hall sensors, the remaining second Hall sensors, excluding the first and last placed Hall sensors, include the first detection signal output terminal 313 and the second detection signal output terminal 314. The first detection signal output terminal 313 of the second Hall sensor is connected to the second detection signal output terminal of the previously placed Hall sensor, and the second detection signal output terminal 314 is connected to the first detection signal output terminal of the next placed Hall sensor. In other words, the first detection signal output terminal of the second placed Hall sensor is connected to the second detection signal output terminal of the first placed Hall sensor, and the second detection signal output terminal of the second placed Hall sensor is connected to the first detection signal output terminal of the third placed Hall sensor.

[0157] Figure 10d shows the connection relationships of the output terminals of the last-placed Hall sensor. The last-placed third Hall sensor includes the first detection signal output terminal 313 and the second detection signal output terminal 314. The first detection signal output terminal 313 of the third Hall sensor is connected to the second detection signal output terminal of the previously placed Hall sensor, and the second detection signal output terminal 314 is connected to the inverting terminal (-) of the amplifier 320.

[0158] As described above, in the present invention, of the two output terminals that each of the two Hall sensors arranged on the outer casing has, only one output terminal is connected to the amplifier 320, and the remaining terminals are all connected to the output terminals of adjacent Hall sensors. In the case of the above connection structure, a signal corresponding to the sum of the sensing ranges of the plurality of Hall sensors is input to the amplifier 320, and the amplifier 320 differentially amplifies this signal and outputs it.

[0159] In an embodiment of the present invention, multiple position sensors, such as Hall sensors, are interconnected, so that only the output terminals of the outermost position sensors are connected to the amplifier. This allows the differential signals from the multiple position sensors to be input to the input terminals of the amplifier.

[0160] According to this, the present invention can provide a differential sensing method with a wider detection range compared to a single sensing method. Furthermore, in the present invention, by inputting the differential signal resulting from the coupling of the multiple position sensors to the input terminal of the amplifier, exposure to offset noise in the path from the output signal of the position sensor to the control unit can be minimized.

[0161] Furthermore, in this invention, by having the sensing unit, which consists of multiple position sensors, an amplifier, and an analog-to-digital converter, output differential signals to the multiple position sensors, the number of patterns and pins connected to the printed circuit board in the drive unit can be minimized, thereby saving space on the printed circuit board.

[0162] Furthermore, in this invention, by calculating the difference value for the multiple position sensors in relation to common-mode noise, it is possible to achieve characteristics that are excellent not only against internal noise but also against external noise.

[0163] Furthermore, in this invention, depending on the operating environment of the camera module, either only the detection signal from a specific position sensor is transmitted to the amplifier stage, or differential signals from multiple position sensors are transmitted. As a result, in this invention, the optimal detection signal can be obtained in environments where high sensing sensitivity is required, and in environments where a wide sensing range is required, respectively.

[0164] Figure 11 is a diagram comparing the connection relationship between a sensor unit according to a comparative example and the sensor unit of the present invention.

[0165] In other words, in order to expand the sensing range of the position sensor, multiple position sensors can be arranged, and the control unit 290 can calculate and use the differential signals for the multiple position sensors.

[0166] In other words, as shown in Figure 11(a), in the comparative example, the output terminals of multiple Hall sensors are each connected to different amplifiers. Furthermore, each amplifier connected to a Hall sensor is connected to a different analog-to-digital converter. Consequently, the control unit must be provided with input pins connected to a large number of analog-to-digital converters. Here, each of the analog-to-digital converters outputs a multi-bit digital signal via a large number of signal lines, and as the number of analog-to-digital converters increases, the number of input pins required in the control unit increases proportionally. Also, in the comparative example, the number of amplifiers and analog-to-digital converters must be equal to the number of Hall sensors.

[0167] However, in this invention, of the multiple Hall sensors, one of the two output terminals of the Hall sensor arranged on the outer casing is connected to the non-inverting terminal (+) and inverting terminal (-) of the amplifier 320, respectively, and the output terminals of the remaining Hall sensors are connected to the output terminals of adjacent Hall sensors. As a result, in this invention, the number of input pins required by the control unit 290 can be minimized, and the problem of the detection signal being exposed to offset noise on the path to the control unit 290 can be minimized.

[0168] Figure 12 is a diagram illustrating the connection relationships of other sensor units according to the present invention.

[0169] In the above, it was explained that each of the plurality of sensor units consists of a Hall sensor. However, in the present invention, the plurality of sensor units may consist of induction coils instead of Hall sensors.

[0170] As shown in Figure 12, the plurality of sensor units include a plurality of induction coils. Each of the plurality of induction coils includes two output terminals, where one of the two output terminals is one end of the induction coil and the other output terminal is the other end of the induction coil.

[0171] The ends of the plurality of induction coils are connected to the ends of adjacent induction coils or to the non-inverting terminal (+) or inverting terminal (-) of the amplifier 320, so as to correspond to the connection relationships of the Hall sensor.

[0172] In other words, the first output terminal of the initially placed induction coil is connected to the non-inverting terminal (+) of the amplifier 320. The second output terminal of the initially placed induction coil is then connected to the first output terminal of the adjacent next induction coil.

[0173] Then, the first output terminal of the second induction coil is connected to the second output terminal of the previously placed induction coil, and the second output terminal of the second induction coil is connected to the first output terminal of the next induction coil.

[0174] Furthermore, the first output terminal of the last-placed induction coil is connected to the second output terminal of the previously placed induction coil, and the second output terminal of the last-placed induction coil is connected to the inverting terminal (-) of the amplifier 320.

[0175] Figure 13 shows the detection range of the position sensor unit according to a comparative example, and Figure 14 shows the detection range of the position sensor unit according to the present invention.

[0176] As shown in Figure 13, when the sensor unit constituting the position sensor section is a single sensor unit, the sensing range of the position sensor section is considerably narrow. In other words, conventional sensing methods use only the output of one sensor, and here, only the linear section (Linear section, X section) of the output of that single sensor is used.

[0177] In contrast, as shown in Figure 14, in the present invention, the position sensor unit consists of a number of sensor units, and the sensing range is determined based on the differential signals to the number of sensor units. Therefore, the present invention can provide a position sensing unit that has a wider sensing range than the comparative example shown in Figure 13.

[0178] Figure 15 is a block diagram showing the detailed configuration of the position sensor unit according to another embodiment of the present invention.

[0179] On the other hand, the position sensor unit described above has a structure in which multiple sensor units are interconnected and provides signals to the amplifier 320. In such a connection structure, the sensing range for the detection signals of the multiple sensor units can be greatly increased, but the sensing sensitivity may decrease compared to a single sensor system.

[0180] Therefore, in the present invention, depending on the operating conditions of the camera module, detection signals from multiple sensor units are supplied to the amplifier 320, or only the detection signal for a specific sensor unit among the multiple sensor units is transmitted to the amplifier 320.

[0181] Therefore, as shown in Figure 15, the position sensor unit further includes a switch 340.

[0182] One end of the switch 340 is connected to the inverting terminal (-) of the amplifier 320, and the other end is connected to one of the output terminals of the plurality of sensor units.

[0183] In other words, if the plurality of sensor units consist of two Hall sensors, the switch 340 is 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.

[0184] In this case, when the switch 340 is connected to the second detection signal output terminal of the first-placed Hall sensor, only the output signal of the first-placed Hall sensor is input to the amplifier 320. Thus, in the present invention, the amplifier 320 is connected only to the specific Hall sensor, thereby providing optimal sensing sensitivity under the conditions for which sensing sensitivity is required.

[0185] Furthermore, when the switch 340 is connected to the second detection signal output terminal of the second Hall sensor, the amplifier 320 receives a combined signal of the output signals of the first Hall sensor and the second Hall sensor. In this way, the present invention makes it possible to provide an optimal sensing range under conditions where a sensing range is required, by connecting the amplifier 320 to the plurality of Hall sensors.

[0186] In an embodiment of the present invention, multiple position sensors, such as Hall sensors, are interconnected, so that only the output terminal of the outermost position sensor is connected to the amplifier. This allows the differential signals from the multiple position sensors to be input to the input terminal of the amplifier.

[0187] According to this, the present invention can provide a differential sensing method with a wider detection range compared to a single sensing method. Furthermore, in the present invention, by inputting the differential signal resulting from the coupling of the multiple position sensors to the input terminal of the amplifier, exposure to offset noise in the path from the output signal of the position sensor to the control unit can be minimized.

[0188] Furthermore, in this invention, by having the sensing unit, which consists of multiple position sensors, an amplifier, and an analog-to-digital converter, output differential signals to the multiple position sensors, the number of patterns and pins connected to the printed circuit board in the drive unit can be minimized, thereby saving space on the printed circuit board.

[0189] Furthermore, in this invention, by calculating the difference value for the multiple position sensors in relation to common-mode noise, it is possible to achieve excellent characteristics not only against internal noise but also against external noise.

[0190] Furthermore, in this invention, depending on the operating environment of the camera module, either only the detection signal from a specific position sensor is transmitted to the amplifier stage, or differential signals from multiple position sensors are transmitted. As a result, in this invention, an optimal detection signal can be obtained in environments where high sensing sensitivity is required, and in environments where a wide sensing range is required, respectively.

[0191] Figure 16 is a flowchart illustrating, step by step, the operation method of the camera module according to the present invention.

[0192] First, the control unit 290 determines the position sensing conditions for the first and second lens assemblies of the camera module (S110). Here, determining the position sensing conditions determines whether the current operating conditions require sensing sensitivity or sensing range for acquiring position data. For example, if the range of movement of the lens assembly is large, a wide sensing range is required for correct position sensing. Conversely, if the range of movement of the lens assembly is small and there is minute movement, correct sensing sensitivity is required rather than a wide sensing range. This allows the control unit to determine the position sensing conditions. Then, the control unit 290 controls the switching operation of the switch 340 according to the predetermined position sensing conditions (S120).

[0193] Next, the control unit 290 receives differential signals from multiple interconnected sensor units or detection signals from a specific sensor unit based on the operation of the switch 340 (S130).

[0194] Then, the control unit 290 calculates the current position of the first or second lens assembly based on the received signal (S140).

[0195] Furthermore, once the current position is calculated, 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 (S150).

[0196] The features, structures, and effects described above are included in at least one embodiment and are not necessarily limited to just one embodiment. Furthermore, the features, structures, and effects exemplified in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary skill in the art to which the present invention belongs. Therefore, such combinations and modifications should be considered to be within the scope of the present invention.

[0197] While the above description has focused on embodiments, these are merely illustrative and do not limit the present invention. Anyone with ordinary skill in the art to which the present invention belongs will understand that multiple modifications and applications not exemplified above are possible, as long as they do not deviate from the essential characteristics of the present invention. For example, each component specifically presented in the present invention can be modified and implemented. The differences in such modifications and applications should be considered to fall within the scope of the present invention as defined in the appended claims.

Claims

1. A fixed lens assembly, A movable lens assembly that moves in the optical axis direction relative to the fixed lens assembly, A drive unit for moving the movable lens assembly in the optical axis direction, The system includes a plurality of sensor units that sense the position in the optical axis direction of the movable lens assembly as it moves in the optical axis direction, The plurality of sensor units include a first sensor unit and a second sensor unit that are arranged adjacent to each other to sense the position of the moving lens assembly in the optical axis direction and whose outputs are 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 polarities of the second detection signal output terminal and the third detection signal output terminal are different from each other. The second detection signal output terminal and the third detection signal output terminal are directly connected to each other in a camera module.

2. The drive unit includes a magnet disposed in the movable lens assembly and moving together with the movable lens assembly in the optical axis direction, The camera module according to claim 1, wherein the first sensor unit and the second sensor unit sense the movement of the magnet in the optical axis direction.

3. The system further includes an input unit connected to the first sensor unit and the second sensor unit, The input unit is directly connected to the first detection signal output terminal and the fourth detection signal output terminal. The camera module according to claim 2, wherein the polarity of the first detection signal output terminal and the polarity of the fourth detection signal output terminal are different.

4. The camera module according to claim 3, wherein the input section includes a first input terminal directly connected to the first detection signal output terminal and a second input terminal directly connected to the fourth detection signal output terminal.

5. The first input terminal is either a non-inverting terminal or an inverting terminal. The camera module according to claim 4, wherein the second input terminal is one of the non-inverting terminal and inverting terminal that is different from the first input terminal.

6. The plurality of sensor units further include a third sensor unit, The third sensor unit includes a fifth detection signal output terminal and a sixth detection signal output terminal, The camera module according to claim 1, wherein the fifth detection signal output terminal is directly connected to either the first detection signal output terminal or the fourth detection signal output terminal.

7. The second sensor unit is positioned between the first and third sensor units. The camera module according to claim 6, wherein the fifth detection signal output terminal is connected in series with the fourth detection signal output terminal.

8. Further comprising an input unit connected to the first sensor unit, the second sensor unit and the third sensor unit, The input section includes first and second input terminals, 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. The camera module according to claim 7, wherein the polarity of the first detection signal output terminal and the polarity of the sixth detection signal output terminal are different.

9. The camera module according to claim 3, wherein the input unit receives a differential signal of the first detection signal of the first sensor unit and the second detection signal of the second sensor unit.

10. The system further includes a drive control unit that controls the aforementioned drive unit, The drive unit further includes a coil positioned opposite the magnet, The camera module according to claim 9, wherein the drive control unit controls the current applied to the coil based on the differential signal received by the input unit.

11. The aforementioned input unit is An amplification unit connected to the first and second sensor units, The camera module according to claim 3, further comprising an analog-to-digital conversion unit connected to the amplification unit.

12. The camera module according to any one of claims 1 to 10, wherein each of the first and second sensor units includes a Hall sensor.

13. Further includes an optical path changing member that changes the optical path, The camera module according to claim 12, wherein the fixed lens assembly is disposed between the optical path changing member and the movable lens assembly.

14. The camera module according to any one of claims 1 to 13, wherein each of the first and second sensor units detects a magnetic force that changes according to the position in the optical axis direction of the movable lens assembly that moves in the optical axis direction.

15. A first lens group that moves in the direction of the optical axis, A second lens group is aligned with the first lens group in the optical axis direction and moves in the optical axis direction, A third lens group is aligned with the first and second lens groups in the optical axis direction and is fixed in position. A first drive unit moves the first lens group in the optical axis direction, A second drive unit moves the second lens group in the optical axis direction, A first position sensor unit that senses the position in the optical axis direction of the first lens group that moves in the optical axis direction, It includes a second position sensor unit that senses the position in the optical axis direction of the second lens group that moves in the optical axis direction, Each of the first position sensor section and the second position sensor section includes a first sensor unit and a second sensor unit that are arranged adjacent to each other to sense the position of the first lens group or the second lens group in the optical axis direction, and whose outputs are 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 polarities of the second detection signal output terminal and the third detection signal output terminal are different from each other. The second detection signal output terminal and the third detection signal output terminal are directly connected to each other in a camera module.

16. The first drive unit includes a first magnet arranged in the first lens group and moving together with the first lens group in the optical axis direction, The second drive unit includes a second magnet that is arranged in the second lens group and moves together with the second lens group in the optical axis direction. The first position sensor unit senses the movement of the first magnet in the optical axis direction, The camera module according to claim 15, wherein the second position sensor unit senses the movement of the second magnet in the optical axis direction.

17. Further comprising an input unit connected to the first position sensor unit and the second position sensor unit, The input unit includes a first input terminal directly connected to the first detection signal output terminal of the first position sensor unit, a second input terminal directly connected to the fourth detection signal output terminal of the first position sensor unit, a third input terminal directly connected to the first detection signal output terminal of the second position sensor unit, and a fourth input terminal directly connected to the fourth detection signal output terminal of the second position sensor unit. The camera module according to claim 16, wherein the polarity of the first detection signal output terminal and the polarity of the fourth detection signal output terminal of the first position sensor unit and the second position sensor unit are different.

18. The camera module according to claim 17, wherein the input unit receives a differential signal of the first detection signal of the first sensor unit of the first position sensor unit and the second detection signal of the second sensor unit of the first position sensor unit, and receives a differential signal of the third detection signal of the first sensor unit of the second position sensor unit and the fourth detection signal of the second sensor unit of the second position sensor unit.

19. The first input terminal and the third input terminal are non-inverting terminals. The camera module according to claim 17, wherein the second input terminal and the fourth input terminal are inverting terminals.

20. The first drive unit includes a first coil positioned opposite the first magnet, The second drive unit includes a second coil positioned opposite the second magnet, The camera module according to claim 17, wherein the input unit controls the current applied to the first coil and the second coil based on the detection signals of the first and second sensor units of the first position sensor unit and the detection signals of the first and second sensor units of the second position sensor unit.

21. The camera module according to any one of claims 15 to 20, wherein each of the first and second sensor units includes a Hall sensor.

22. Further includes an optical path changing member that changes the optical path, The optical path changing member, the third lens group, the second lens group, and the first lens group are arranged in sequence. The second lens group is a focusing lens assembly that performs a focusing function, The camera module according to claim 21, wherein the first lens group is a zoom lens assembly that performs a zooming function.

Images