JP2012208063A - Position detecting device and actuator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify an arrangement configuration of a magnetic sensor and a magnet with respect to a substrate, and even when using a general-purpose substrate and magnet, to miniaturize, thin, and reduce the weight of a device without lowering a detecting accuracy by reducing a gap between the substrate and the magnet.SOLUTION: At least one or more magnetic sensors 53 are disposed on a substrate 51 out of a region where magnets 52 are projected on the substrate 51, and the magnetic sensitive direction of the magnetic sensor 53 is perpendicular to the substrate 51. The magnet 52 is movable in any one direction in a plane parallel to the substrate 51. The magnet is disposed on the same surface side as the magnetic sensor 53 such that a distance A that is a proximal part from the substrate 51 is supported closer to the substrate 51 than a distance B that is a distal part of the magnetic sensor 53, and is magnetized by the N pole and S pole that are aligned in the moving direction.

Description

  The present invention relates to a position detection device and an actuator using the position detection device, and more specifically, simplifies the arrangement configuration of a magnetic sensor and a magnet with respect to the substrate, and reduces the gap between the substrate and the magnet without reducing detection accuracy. The present invention relates to a position detection device and an actuator using the position detection device which are reduced in size, thickness, and weight.

  In recent years, various position detection devices are mounted on various devices. For example, camera shake correction devices used in digital still cameras, digital video cameras, and mobile phone camera modules, and lens position detection devices for zooming and AF (autofocus), have a function for instantaneously detecting positions with high accuracy. At the same time, there is a demand for downsizing, thinning, and weight reduction of the entire device.

  In order to meet such demands, position detection devices using magnetic sensors are widely known. In this type of position detection device, a magnetic sensor is provided on a substrate, and a magnet that can be moved in a plane parallel to the substrate is provided almost directly above the magnetic sensor. The position of a lens or the like attached to the magnet is detected based on the output.

  FIG. 1 is a specific configuration diagram for explaining a conventional position detection device, which is disclosed in Patent Document 1. In FIG. The thing of this patent document 1 is related with the position detection apparatus which detects the relative position of two objects, and the position detection apparatus 20 and two holes arrange | positioned mutually apart from one magnet (magnetic force generation body) 21. Elements (in other words, a pair of Hall element pairs (magnetic sensor pairs)) 22a and 22b are provided. The magnet 21 has a prismatic shape, and its upper surface side and lower surface side are magnetized to N and S poles, respectively. The Hall element pairs 22a and 22b are attached to a fixed-side object (fixed member) such as the apparatus main body, and the magnet 21 is attached to a moving-side object (moving member) that moves relative to the fixed member. The magnet 1 attached to the moving member is movable in the direction of the arrow AR1 (X direction) in the figure with respect to the Hall element pair 22a, 22b attached to the fixed member. The position detection device 20 detects the relative position of the magnet 21 with respect to the Hall element pairs 22a and 22b.

  FIG. 2 is a configuration diagram for explaining an actuator equipped with a conventional position detection device, which is disclosed in Patent Document 2. In FIG. A laminated coil for driving a lens is integrally arranged on the laminated substrate 35, and the hall element 31 is arranged on the laminated substrate 35 via a flexible printed board 34. Further, the opposing yoke 33 is formed with a recess 33a stepped by pressing at a portion facing the hall element 31.

  When a current flows through the coil of the laminated substrate 35, an electromagnetic force is generated by the action of the magnetic field generated by the magnet 30 and the current flowing through the coil. Specifically, the lens can be moved in two directions, the X direction and the Y direction, which are substantially orthogonal to the optical axis, by controlling the current flowing in the coil disposed opposite to the magnet 30. The gap between the multilayer substrate 35 and the counter yoke 33 in the periphery of the Hall element 31 can be partially increased by stepping the counter yoke 33 to form a recess 33a in a portion facing the Hall element 31. it can. As a result, the gap between the magnet 30 and the counter yoke 33 can be reduced, so that the electromagnetic force of the coil can be increased and a sufficient gap between the hall element 31 and the counter yoke 33 can be secured. Also in this case, the Hall element 31 and the magnet 30 are arranged in a vertical arrangement with respect to the opposing yoke 33. Reference numeral 32 denotes a back yoke.

  FIG. 3 is a block diagram for explaining an actuator to which a conventional lens unit is attached. This type of actuator is provided with a position detection device including a driving magnet and a magnetic sensor. The actuator 40 is provided on the mounting substrate 41, a lens barrel 45 holding a lens 46 movably disposed on the mounting substrate 41, an X-axis driving magnet 42 </ b> X attached to the lens barrel 45, and An X-axis drive coil 44X and an X-axis magnetic sensor 43X are provided almost directly below the X-axis drive magnet 42X. In addition, a Y-axis driving magnet 42Y attached to the lens barrel 45, a Y-axis driving coil 44Y provided on the mounting substrate 41 and disposed immediately below the Y-axis driving magnet 42Y, and a Y-axis driving magnetic sensor. 43Y.

  With such a configuration, the X-axis and Y-axis drive coil 44X is based on the signal for instructing the position where the lens barrel 45 should move and the position signals detected by the X-axis and Y-axis magnetic sensors 43X and 43Y. , 44Y is controlled. In this case, the X-axis and Y-axis magnetic sensors 43X and 43Y are arranged in a vertical arrangement with respect to the mounting substrate 41 almost directly below the X-axis and Y-axis drive magnets 42X and 42Y.

  FIG. 4 is a configuration diagram for explaining an actuator equipped with a conventional position detection device. The magnet 120 has a thick portion 120a and a thin portion 120b. An actuator coil (not shown) is opposed to the thick portion 120a, and a position detecting Hall element 121 is opposed to the thin portion 120b. Since the Hall element 121 is disposed so as to protrude from the surface of the multilayer substrate 119 via the flexible printed circuit board 124, a part of the Hall element 121 is disposed in the recess formed by the thin portion 120b. Therefore, the yoke 125 can be reduced in size and thickness. Further, the distance between the magnet 120 and the coil and the distance between the magnet 120 and the hall element 121 can be set to optimum distances, respectively, and sufficient thrust as an actuator can be obtained even if the size and thickness are reduced.

JP 2005-331400 A JP 2007-241265 A

  In general, an actuator is a device that converts energy such as electricity into physical motion. Conventionally, actuators used in camera lens drive units are mainly linear motors that use a drive magnet and a drive coil. there were. A higher torque can be obtained by bringing the drive magnet and the drive coil as close as possible. Therefore, the drive magnet and the drive coil can be made smaller by bringing them closer to each other. And weight reduction can be achieved. However, the conventional position detection device shown in FIGS. 1 and 3 requires an additional gap between the substrate and the magnet by the thickness of the magnetic sensor because the magnetic sensor is disposed almost directly below the magnet. It was not possible to further reduce the size, thickness, and weight of the device by reducing the gap between the substrate and the magnet. The conventional position detection device shown in FIGS. 2 and 4 is devised to reduce the height, but the substrate or magnet needs to be processed, and a general-purpose substrate or magnet can be used. could not. Furthermore, in the conventional position detection apparatus shown in FIG. 4, in order to form the thin portion 120b in the magnet 120, it is necessary to further cut off a part of the magnet processed into a strip shape by machining. When the magnet 120 is produced by such a construction method, there is a problem that a machining cost increases because a step of scraping a part of the magnet 120 is required. In addition, since a portion to be scraped off is generated in the magnet 120, a larger amount of magnetic material is required to form a magnet having the same volume, and there is a problem that the material cost of the magnet is relatively increased.

  The present invention has been made in view of such a problem, and an object of the present invention is to simplify the arrangement of the magnetic sensor and the magnet with respect to the substrate, and to reduce the detection accuracy and to reduce the detection accuracy. Even in the case of using a magnet, it is an object of the present invention to provide a position detection device and an actuator using the same, in which the gap between the substrate and the magnet is reduced to reduce the size, thickness and weight of the device.

  The present invention has been made to achieve such an object, and in the invention according to claim 1, at least one or more magnetic sensors are arranged on a substrate, and the magnetic sensing direction of the magnetic sensor is the above-described magnetic sensing direction. The magnetic flux detection means that is perpendicular to the substrate and can move in any one direction of movement within a plane parallel to the substrate, and the distance of the closest part from the substrate is the maximum distance of the magnetic sensor. Magnetic flux generating means comprising a magnet that is arranged in the vicinity of the magnetic flux detecting means so as to be supported nearer to the substrate than the distance of the remote part, and is magnetized with N and S poles aligned in the moving direction. The magnetic sensor is disposed outside the region where the magnet is projected onto the substrate, and the magnetic flux generating means is moved a predetermined distance in the moving direction with respect to the substrate on which the magnetic sensor is mounted. When moving, move in the moving direction. And performing position detection by using the output value from the magnetic sensor corresponding to the distance.

  According to a second aspect of the present invention, in the first aspect of the present invention, the magnetic flux generating means is magnetized such that the N pole and the S pole are aligned in the moving direction, and the N pole and the S in the vertical direction. It consists of a magnet having a laminated structure in which two poles are magnetized side by side.

  According to a third aspect of the present invention, in the first aspect of the present invention, the magnetic flux generating means is horizontally aligned with N and S poles aligned in the moving direction and perpendicular to the moving direction. It consists of the magnet of the connection structure magnetized by arranging two north poles and two south poles in the direction.

  According to a fourth aspect of the present invention, there is provided a position detection device according to any one of the first to third aspects, a position detection mechanism of a camera shake correction lens to which an output signal from the position detection device is input, or an auto An actuator including a focus mechanism or a zoom mechanism.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the camera shake correction lens position detection mechanism, autofocus mechanism, or zoom mechanism is a camera shake correction lens of a digital camera or a mobile phone. It is used as a position detection mechanism, an autofocus mechanism, or a zoom mechanism.

  The invention according to claim 6 is the invention according to claim 5, wherein the magnet includes an X-axis driving magnet and a Y-axis driving magnet.

  According to the present invention, the substrate does not need to be subjected to special processing such as a hole or a recess, and the magnet can move in any one direction within a plane parallel to the substrate, and the closest portion from the substrate Is arranged on the same side as the magnetic sensor so that it is supported closer to the substrate than the distance of the remotest part of the magnetic sensor, and the back surface is all processed into a special shape other than a parallelepiped The magnetic sensor is arranged outside the region in which the magnet is projected onto the substrate, and the magnetic sensor and the magnet on the substrate are arranged. A position detecting device that simplifies the arrangement and reduces the gap between the substrate and the magnet without lowering the detection accuracy, thereby reducing the size, thickness, and weight of the device, and an actuator using the position detecting device. Can be realized.

It is a concrete block diagram for demonstrating the conventional position detection apparatus, (a) is sectional drawing, (b) is a top view. It is a block diagram for demonstrating the actuator carrying the conventional position detection apparatus. It is a block diagram for demonstrating the actuator to which the conventional lens unit is attached. It is a block diagram for demonstrating the actuator carrying the conventional position detection apparatus. 3A and 3B are explanatory diagrams for comparison with the position detection device of the present invention, in which FIG. 3A is a configuration diagram of an actuator for a Y-axis in FIG. 3, and FIG. It is a side view for contrast with the position detection apparatus of this invention, and is a side view in FIG. It is another side view for contrast with the position detection apparatus of this invention. It is another side view for contrast with the position detection apparatus of this invention. It is a schematic block diagram for demonstrating the actuator using the position detection apparatus which concerns on this invention, and is a side view of the actuator for Y axes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an arrangement configuration diagram of a magnetic sensor and a magnet for explaining a first embodiment of a position detection device according to the present invention, where (a) is a top view, (b) is a front view, and (c) is a side view. It is a perspective view for demonstrating the arrangement structure of the north-pole and the south pole of the magnet in Fig.10 (a) thru | or (c). FIG. 12A is a diagram illustrating specific numerical values in the conventional and the present invention, particularly regarding the height relationship between the coil and the magnet, and FIG. 12A is a configuration diagram illustrating the specific numerical values of FIG. ) Is a block diagram showing specific numerical values in FIG. 12 is a graph plotting the relationship between the distance from the center of the coil in the height direction and the magnetic flux density obtained from the coil when 0.1 mA is applied to the coil in the configuration of FIGS. FIG. 11 is an arrangement diagram for explaining the arrangement relationship between a magnetic sensor and a magnet that cannot detect the position in FIG. 10, (a) is a front view, and (b) is a side view. FIG. 5 is a layout diagram of a magnetic sensor and magnets for explaining a second embodiment of the position detection apparatus according to the present invention, wherein (a) is a top view, (b) is a front view, and (c) is a side view. It is a perspective view for demonstrating the arrangement structure of the north-pole and south pole of the magnet in Fig.15 (a) thru | or (c). FIG. 5 is a layout diagram of a magnetic sensor and magnets for explaining a third embodiment of the position detection apparatus according to the present invention, wherein (a) is a top view, (b) is a front view, and (c) is a side view. It is a perspective view for demonstrating the arrangement structure of the north-pole and the south pole of the magnet in Fig.17 (a) thru | or (c). FIG. 18 is an arrangement diagram for explaining the arrangement relationship between a magnetic sensor and a magnet that cannot detect the position in FIG. 17, (a) is a front view, and (b) is a side view. It is explanatory drawing which shows the comparative example 1, (a) is a figure which shows the magnet size (height a, depth b, width L), the gap (GAP) of a magnet and a magnetic sensor, and the moving direction of a magnet, (b). Indicates setting conditions such as magnet size. 20A and 20B are characteristic diagrams, in which FIG. 20A shows the relationship of magnetic flux density to stroke (magnet movement distance), and FIG. 20B shows the relationship of accuracy to stroke. It is explanatory drawing which shows the simulation in this invention, (a) is a figure which shows the magnet size (height a, depth b, width L), the gap (GAP) of a magnet and a magnetic sensor, and the moving direction of a magnet, ) Indicates setting conditions such as magnet size. 22A and 22B are characteristic diagrams, in which FIG. 22A shows the relationship of magnetic flux density to stroke (magnet movement distance), and FIG. 22B shows the relationship of accuracy to stroke. It is a concrete block diagram for demonstrating the actuator using the position detection apparatus which concerns on this invention.

  First, before describing each embodiment of the present invention, the position detection device in the Y-axis actuator described in FIG. 3 will be described for comparison with the present invention.

  5A and 5B are explanatory diagrams for comparison with the position detection device of the present invention, FIG. 5A is a configuration diagram of the Y-axis actuator in FIG. 3, and FIG. FIG. 6 is a cross-sectional view taken along the plane AA ′ of FIG. A Y-axis driving magnet 42Y attached to the lens barrel 45, a Y-axis driving coil 44Y and a Y-axis magnetic sensor 43Y provided on the mounting substrate 41 and disposed immediately below the Y-axis driving magnet 42Y. I have. As can be seen from FIG. 5A, the Y-axis magnetic sensor 43Y is arranged in a vertical arrangement with respect to the mounting substrate 41 almost directly below the Y-axis drive magnet 42Y.

  FIG. 6 is a side view for comparison with the position detection apparatus of the present invention, and is a side view in FIG. The Y-axis magnetic sensor 43Y is arranged in a vertical arrangement with respect to the mounting substrate 41 almost directly below the Y-axis drive magnet 42Y.

  The relationship between the Y-axis driving magnet 42Y and the Y-axis driving coil 44Y is desired to be close in order to increase the torque, but is limited because of the Y-axis magnetic sensor 43Y. In addition, the relationship between the Y-axis driving magnet 42Y and the Y-axis magnetic sensor 43Y is better because the linearity is better when they are separated, but when they are separated, the Y-axis driving magnet 42Y and the Y-axis driving coil 44Y There are limitations because the torque becomes weaker. As a result, due to the trade-off relationship between torque and linearity, a distance (= height) between the opposite surface of the Y-axis driving magnet 42Y facing the mounting substrate 41 and the mounting substrate is required to some extent.

  FIG. 7 is another side view for comparison with the position detection device of the present invention, and is a diagram showing the arrangement relationship between the driving magnet and the magnetic sensor shown in FIG. The Y-axis magnetic sensor 43Y is arranged in a vertical arrangement with respect to the mounting substrate 41 almost directly below the Y-axis drive magnet 42Y. In order to bring the Y-axis driving magnet 42Y and the Y-axis driving coil 44Y closer, and further to separate the Y-axis driving magnet 42Y and the magnetic sensor 43Y, a cutout is provided in the Y-axis driving magnet 42Y. Since the drive magnet is not a general-purpose product, there is a problem that it takes time to manufacture.

  FIG. 8 is still another side view for comparison with the position detecting device of the present invention, and is a diagram showing the arrangement relationship between the driving magnet and the magnetic sensor shown in FIG. The Y-axis magnetic sensor 43Y is arranged in a vertical arrangement with respect to the mounting substrate 41 almost directly below the Y-axis drive magnet 42Y. In order to bring the Y-axis driving magnet 42Y and the Y-axis driving coil 44Y closer, and further to separate the Y-axis driving magnet 42Y and the magnetic sensor 43Y, a hole is made in the mounting board 41, and the magnetic sensor 43Y is inserted therein. It is out. Also in this case, since the mounting substrate 41 is not a general-purpose product, there is a problem that it takes time to manufacture.

Embodiments according to the present invention will be described below with reference to the drawings.
FIG. 9 is a schematic configuration diagram for explaining an actuator using the position detection device according to the present invention, and shows a side view of the Y-axis actuator. In the figure, reference numeral 51 denotes a mounting substrate (hereinafter simply referred to as a substrate), 52 is a driving magnet (magnetic flux generating means; hereinafter simply referred to as a magnet), 53 is a magnetic sensor (magnetic flux detecting means), and 54 is a driving coil (hereinafter simply referred to as a coil). ). Symbol A indicates the distance (gap) between the substrate 51 and the lower surface of the magnet 52 in the vertical direction, and indicates the distance from the substrate 51 to the closest portion of the magnet 52. Reference sign B indicates the distance between the substrate 51 and the upper surface of the magnetic sensor 53 in the vertical direction, and indicates the distance from the substrate 51 to the most remote portion of the magnetic sensor 53.

  The actuator of the present invention includes a substrate 51, a magnetic sensor 53 provided on the substrate 51, a magnet 52 provided in the vicinity of the magnetic sensor 53 and on the substrate 51 via a gap, A coil 54 is provided on the substrate 51 almost directly below the magnet 52. The magnetic sensor 53 provided on the substrate 51 is arranged in the vicinity of the coil 54 on the substrate 51 and the magnet 52 provided thereon, that is, in a horizontal arrangement. That is, the magnet 52 and the coil 54 can be brought close to each other, and the torque is increased by the close amount, so that the magnet 52 or the coil 54 can be made small. For the linearity, the magnetic sensor 53 may be arranged at the optimum position from the magnet 52 (left and right direction in FIG. 9).

  Accordingly, the arrangement of the magnetic sensor and the magnet with respect to the substrate is simplified, and even when a general-purpose substrate and magnet are used without reducing detection accuracy, the gap between the substrate and the magnet is reduced. An actuator using a position detection method and a position detection apparatus that can be reduced in size, thickness, and weight can be realized.

  FIGS. 10A to 10C are arrangement diagrams of a magnetic sensor and a magnet for explaining the first embodiment of the position detection apparatus according to the present invention. FIG. 10A is a top view, and FIG. ) Is a front view, and FIG. 10C is a side view. FIG. 11 is a perspective view for explaining the arrangement structure of the N and S poles of the magnets in FIGS. 10 (a) to 10 (c). In addition, the same code | symbol is attached | subjected to the component which has the same function as FIG. The notation N (S) means that the S pole exists behind the N pole. An arrow inside the magnet indicates the direction of magnetization, and an arrow outside the magnet indicates the moving direction.

  As shown in FIG. 9, the position detection device according to the first embodiment of the present invention includes a substrate 51, a magnetic sensor 53 provided on the substrate 51, a side portion near the magnetic sensor 53, and It is comprised from the magnet 52 provided in the board | substrate 51 through the gap.

  At least one magnetic sensor 53 is disposed on the substrate 51, and the magnetic sensing direction of the magnetic sensor 53 is perpendicular to the substrate 51. Further, the magnet 52 can move in any one direction within a plane parallel to the substrate 51, and the distance A of the closest part from the substrate 51 is larger than the distance of the remotest part B of the magnetic sensor 53. It is a magnet that is arranged in the vicinity of the magnetic sensor 53 so as to be supported in the vicinity, and is magnetized with the N and S poles aligned in the moving direction.

  When the magnet 52 is moved by a predetermined distance in the moving direction with respect to the substrate 51 on which the magnetic sensor 53 is mounted, position detection is performed using an output value from the magnetic sensor 53 corresponding to the moving distance in the moving direction. .

  Further, the position detection method of the present invention is based on the magnetic sensor 53 corresponding to the movement distance in the movement direction when the magnet 52 is moved by a predetermined distance in the movement direction with respect to the substrate 51 on which the magnetic sensor 53 is mounted. Is used to detect the position of the magnet 52, and at least one magnetic sensor 53 is disposed on the substrate 51 so that the magnetic sensing direction of the magnetic sensor 53 is perpendicular to the substrate 51. The magnet having the N pole and the S pole magnetized side by side in the moving direction so that the distance of the closest part from the substrate 51 is supported closer to the substrate 51 than the distance of the remotest part of the magnetic sensor 53. Position detection is performed by arranging 52 in the vicinity of the magnetic sensor 53 so as to be movable in one arbitrary direction within a plane parallel to the substrate 51.

  As described above, in the position detection device according to the present invention, the magnet 52 can move in any one direction within a plane parallel to the substrate 51, and the distance of the closest portion A from the substrate 51 is the magnetic sensor 53. The magnetic sensor 53 and the magnet 52 are arranged in a lateral arrangement with respect to the substrate 51 so as to be supported nearer to the substrate than the distance B of the most remote portion. As a result, the arrangement of the magnetic sensor and the magnet with respect to the substrate is simplified, and the gap between the substrate and the magnet is reduced without reducing the detection accuracy, thereby reducing the size, thickness and weight of the device. Thus, the position detection method and the position detection apparatus can be realized.

  The magnet 52 is disposed on the side near the magnetic sensor 53 so that the distance A of the closest part from the substrate 51 is supported closer to the substrate 51 than the distance of the remotest part B of the magnetic sensor 53. As a result, the coil 54 and the magnet 52 in FIG. 9 can be brought close to each other, and the height from the substrate can be reduced. This will be described below with reference to FIGS.

  12A is a configuration diagram illustrating specific numerical values in FIG. 6, and FIG. 12B is a configuration diagram illustrating specific numerical values in FIG. 9. Conventionally, in order to improve the linearity of the magnetic sensor, it has been necessary to separate the magnet from the magnetic sensor. For example, since the thickness is about 0.3 mm and the thickness of the magnetic sensor is 0.38 mm, the distance from the substrate to the magnet was 0.68 mm. However, in the present invention in which the magnetic sensor is not disposed in the region where the magnet is projected onto the substrate, the magnet and the coil can be brought close to each other, and it is only necessary to obtain the same torque as the conventional one, so the coil can be made small. It becomes.

  FIG. 13 shows the magnetic flux density obtained from the coil in the states of FIGS. 12A and 12B for each distance in the height direction at the center of the coil. Specifically, the coil thickness in FIG. 12 (a) is 0.3 mm, the number of turns is 30 turns, the energizing current is 0.1 mA, and the coil thickness in FIG. 12 (b) is 0.15 mm. The number of turns is 15 turns, and the energizing current is the same 0.1 mA. In the configuration of FIG. 12A, the magnetic flux from the center of the coil at 0.68 mm from the substrate, that is, 0.38 mm from the coil, is 1.151 mT. In the configuration of FIG. 12 (b), the distance in the height direction from the coil at which a magnetic flux of 1.151 mT or more is obtained is 0.09 mm. Accordingly, in the configuration of FIG. 12B, the distance from the substrate to the magnet is 0.24 mm. That is, in the configuration of FIG. 12B, the magnet can be brought closer to the substrate of 0.68 mm−0.24 mm = 0.44 mm than the configuration of FIG. Needless to say, 0.44 mm is a useful effect in a camera module of a mobile phone that is required to have a total height of about 4 mm, and is about 11% lower.

  14 (a) and 14 (b) are arrangement diagrams for explaining the arrangement relationship between the magnetic sensor and the magnet that cannot detect the position in FIG. 10, and FIG. 14 (a) is a front view, and FIG. b) is a side view. In the figure, reference numeral 53 a indicates a magnetic sensitive part of the magnetic sensor 53. In the first embodiment, the positional relationship in the height direction between the magnet 52 and the magnetic sensor 53 is limited. That is, when the center of the height of the magnet 52 is the same as the height of the magnetic sensing surface 53a that senses the magnetic field of the magnetic sensor 53, there is no vertical component in the magnetic field applied to the Hall element. It cannot be detected. In other words, if the center of the height of the magnet 52 and the height of the magnetic sensitive surface of the magnetic sensor 53 are different, the position can be detected.

  FIGS. 15A to 15C are arrangement diagrams of a magnetic sensor and a magnet for explaining a second embodiment of the position detection apparatus according to the present invention. FIG. 15A is a top view, and FIG. ) Is a front view, and FIG. 15C is a side view. FIG. 16 is a perspective view for explaining an arrangement structure of N poles and S poles of the magnets in FIGS. In the figure, reference numeral 61 denotes a substrate, 62 denotes a magnet (magnetic flux generating means), and 63 denotes a magnetic sensor (magnetic flux detecting means). The notation of S (N) means that the N pole exists behind the S pole, and the notation of N (S) means that the S pole exists behind the N pole.

  The position detection apparatus according to the second embodiment of the present invention differs from the first embodiment described above in the arrangement structure of the north and south poles of the magnet, and the configuration of other magnetic sensors and the like is the same. That is, the magnet 62 is a magnet having a laminated structure in which N poles and S poles are magnetized side by side in the moving direction, and two N poles and S poles are magnetized side by side in the vertical direction.

  In the position detection method according to the second embodiment of the present invention, the magnet 62 is magnetized such that the N pole and the S pole are aligned in the moving direction and the N pole and the S pole are aligned in the vertical direction. This is a position detection method using magnets having a laminated structure.

  By configuring in this way, the same effects as those of the first embodiment described above can be obtained. In addition, since a magnet having a laminated structure is used, the magnetic flux density applied to the magnetic sensor and the coil can be approximately double that of the first embodiment.

  FIGS. 17A to 17C are arrangement diagrams of a magnetic sensor and a magnet for explaining a third embodiment of the position detection apparatus according to the present invention. FIG. 17A is a top view and FIG. ) Is a front view, and FIG. 17C is a side view. FIG. 18 is a perspective view for explaining the arrangement structure of the N and S poles of the magnets in FIGS. 17 (a) to 17 (c). In the figure, reference numeral 71 is a substrate, 72 is a magnet (magnetic flux generating means), and 73 is a magnetic sensor (magnetic flux detecting means). The notation of S (N) means that the N pole exists behind the S pole, and the notation of N (S) means that the S pole exists behind the N pole.

  The position detection device according to the third embodiment of the present invention differs from the first embodiment described above in the arrangement structure of the north and south poles of the magnet, and the other configurations of the magnetic sensor and the like are the same. In other words, the magnet 72 is a magnet having a connected structure in which N and S poles are magnetized side by side in the moving direction, and two N and S poles are magnetized in the horizontal direction perpendicular to the moving direction. is there.

  In the position detection method according to the third embodiment of the present invention, the magnet 72 is magnetized such that the N pole and the S pole are aligned in the moving direction, and the N pole and the S pole are 2 in the horizontal direction orthogonal to the moving direction. This is a position detection method using an articulated magnet magnetized side by side.

  By configuring in this way, the same effects as those of the first embodiment described above can be obtained. In addition, since the articulated magnet is used, the magnetic flux density applied to the magnetic sensor can be increased.

  FIGS. 19A and 19B are arrangement diagrams for explaining the arrangement relationship between the magnetic sensor and the magnet that cannot detect the position in FIG. 17, and FIG. 19A is a front view, and FIG. b) is a side view. Reference numeral 73 a in the figure indicates a magnetic sensitive part of the magnetic sensor 73. In the third embodiment, the positional relationship in the height direction between the magnet 72 and the magnetic sensor 73 is limited. That is, when the center of the height of the magnet 72 and the height of the magnetic sensing surface 73a that senses the magnetic field of the magnetic sensor 73 are the same, there is no vertical component in the magnetic field applied to the Hall element. It cannot be detected. In other words, if the center of the height of the magnet 72 and the height of the magnetic sensitive surface of the magnetic sensor 73 are different, the position can be detected.

  Next, a comparison between the position detection device of the present invention and a conventional position detection device, particularly detection accuracy based on the positional relationship between the magnetic sensor and the magnet with respect to the substrate will be described.

  FIGS. 20A and 20B are explanatory views showing Comparative Example 1. FIG. 20A shows the magnet size (height a, depth b, width L) and the gap between the magnet lower surface and the magnetic sensor upper surface ( GAP) is a diagram showing the moving direction of the magnet, and FIG. 20B shows setting conditions such as the magnet size. FIGS. 21A and 21B are characteristic diagrams in FIGS. 20A and 20B. FIG. 21A shows the relationship of the magnetic flux density to the stroke (magnet moving distance). b) is a diagram showing the relationship of accuracy to stroke.

  In Comparative Example 1, the magnet size a is 1 mm, b is 1.4 mm, L is 3.2 mm, the gap is 1.2 mm, etc., and the magnets are parallel on the substrate under the setting conditions shown in FIG. The magnetic flux density and accuracy when moved are shown in FIGS. 21 (a) and 21 (b). That is, when the boundary between the N pole and the S pole of the magnet is located directly above the magnetic sensor and moves ± 0.5 mm in the moving direction of the magnet, the magnetic flux density applied to the magnetic sensor is as shown in FIG. It is a graph of. 21 (b) is obtained by converting the difference between the ideal straight line and the actually applied magnetic flux density into a distance by using a straight line connecting both end points, that is, two points of +0.5 mm and −0.5 mm as an ideal straight line. It is a graph of. The largest deviation from the ideal straight line is the maximum position detection error, but it can be seen from 21 (b) that the maximum position detection error is 0.92 μm. The distance from the substrate to the top surface of the magnet is the height of the magnet (a) + GAP + the thickness of the magnetic sensor, which is 1.0 + 1.2 + 0.38 = 2.58 mm.

  22 (a) and 22 (b) are explanatory views showing the simulation in the present invention. FIG. 22 (a) shows the magnet size (height a, depth b, width L) and the gap between the magnet lower surface and the magnetic sensor upper surface. (GAP) is a diagram showing the moving direction of the magnet, and FIG. 22B shows setting conditions such as the magnet size. FIGS. 23A and 23B are characteristic diagrams in FIGS. 22A and 22B. FIG. 23A shows the relationship of the magnetic flux density to the stroke (magnet moving distance). b) is a diagram showing the relationship of accuracy to stroke.

  In the present invention, the magnet a is 1 mm, b is 2.5 mm, L is 2 mm, the gap is moved in parallel on the substrate under the setting conditions shown in FIG. The magnetic flux density and accuracy in this case are shown in FIGS. 23 (a) and 23 (b). That is, when the boundary between the N pole and the S pole of the magnet exists right next to the magnetic sensor, the magnetic flux density applied to the magnetic sensor is as shown in FIG. It is a graph. 23 (b) is obtained by converting the difference between the ideal straight line and the actually applied magnetic flux density into a distance by using a straight line connecting both end points, that is, two points of +0.5 mm and −0.5 mm as an ideal straight line. It is a graph. The value with the largest deviation from the ideal straight line is the maximum position detection error, but it can be seen from 23 (b) that the maximum position detection error is 0.95 μm. The distance from the substrate to the top surface of the magnet is the height of the magnet (a) + GAP + the thickness of the magnetic sensor, which is 1.0 + (− 0.38) + 0.38 = 1.0 mm.

  As described above, the position detection device according to the present invention is superior to the conventional position detection device in that the distance from the substrate to the upper surface of the magnet can be remarkably reduced while maintaining the same maximum position detection error. Therefore, the apparatus, which is the initial object of the present invention, can be reduced in size, thickness, and weight.

  FIG. 24 is a specific configuration diagram for explaining an actuator using the position detection device according to the present invention, and is a configuration diagram of an actuator incorporating the position detection devices according to the first to third embodiments of the present invention described above. is there. In the figure, reference numeral 80 is an actuator, 81 is a mounting board, 82X is an X-axis drive magnet, 82Y is a Y-axis drive magnet, 83X is an X-axis magnetic sensor, 83Y is a Y-axis magnetic sensor, and 84X is an X-axis drive. Coil, 84Y is a Y-axis drive coil, 85 is a lens barrel, and 86 is a lens.

  The actuator of the present invention is provided with a position detection device including a driving magnet and a magnetic sensor. The actuator 80 is provided on the mounting substrate 81, a lens barrel 85 that holds a lens 86 that is movably disposed on the mounting substrate 81, an X-axis driving magnet 82 </ b> X attached to the lens barrel 85, and An X-axis driving coil 84 disposed almost directly below the X-axis driving magnet 82X, and provided on the mounting board 81, parallel to the moving direction that avoids the X-axis driving magnet 82X and below the mounting board. And an X-axis magnetic sensor 83X disposed laterally on the X-axis drive coil 84X.

  Further, a Y-axis driving magnet 82Y attached to the lens barrel 85 and a Y-axis driving coil 84Y provided on the mounting board 81 and disposed immediately below the Y-axis driving magnet 82Y, and a mounting board 81 And a Y-axis magnetic sensor 83Y disposed in parallel with the mounting axis on the Y-axis driving coil 84Y in parallel with the moving direction avoiding the position directly below the Y-axis driving magnet 82Y.

  With such a configuration, the X-axis and Y-axis driving coil 84X is based on the signal for instructing the position to which the lens barrel 85 should move and the position signals detected by the X-axis and Y-axis magnetic sensors 83X and 83Y. , 84Y is controlled. In this case, the X-axis and Y-axis magnetic sensors 83X and 83Y drive the X-axis and Y-axis with respect to the mounting board in parallel with the moving direction avoiding the X-axis and Y-axis drive magnets 82X and 82Y. The coils 84X and 84Y are arranged in a horizontal arrangement.

  The actuator of the present invention includes the above-described position detection device of the present invention and a position detection mechanism of an image stabilization lens to which an output signal from the position detection device is input, an autofocus mechanism, or a zoom mechanism. Yes. Further, the camera shake correction lens position detection mechanism, autofocus mechanism, or zoom mechanism can be used as a camera shake correction lens position detection mechanism, autofocus mechanism, or zoom mechanism of a digital camera or mobile phone.

  With this configuration, the arrangement of the magnetic sensor and the magnet with respect to the substrate is simplified, and the gap between the substrate and the magnet can be obtained even when a general-purpose substrate and magnet are used without reducing detection accuracy. It is possible to realize an actuator using a position detecting device that is made smaller to reduce the size, thickness, and weight of the device.

20 Position detection device 21 Magnet 22a, 22b, Hall element pair (magnetic sensor pair)
30 Magnet 31 Hall element 32 Back yoke 33 Opposing yoke 33a Recess 34 Flexible printed circuit board 35 Laminated board 40 Actuator 41 Mounting board 42X X-axis driving magnet 42Y Y-axis driving magnet 43X X-axis magnetic sensor 43Y Y-axis driving magnetic sensor 44X X-axis driving coil 44Y Y-axis driving coil 46 Lens 45 Lens barrel 51, 61, 71 Substrate 52, 62, 72 Magnet (magnetic flux generating means)
53, 63, 73 Magnetic sensor (magnetic flux detection means)
53a, 73a Magnetosensitive surface 54 Coil 80 Actuator 81 Mounting board 82X X-axis drive magnet 82Y Y-axis drive magnet 83X X-axis magnetic sensor 83Y Y-axis magnetic sensor 84X X-axis drive coil 84Y Y-axis drive coil 85 Lens barrel 86 Lens 119 Laminated substrate 120 Magnet 120a Thick part 120b Thin part 121 Hall element 124 Flexible printed circuit board 125 Yoke

Claims (6)

At least one magnetic sensor disposed on a substrate, and magnetic flux detection means in which the magnetic sensing direction of the magnetic sensor is perpendicular to the substrate;
It can move in any one direction of movement in a plane parallel to the substrate, and the distance of the closest part from the substrate is supported closer to the substrate than the distance of the remotest part of the magnetic sensor. A magnetic flux generating means comprising a magnet that is arranged in the vicinity of the magnetic flux detecting means and is magnetized with N and S poles aligned in the moving direction,
The magnetic sensor is disposed outside the region where the magnet is projected onto the substrate,
When the magnetic flux generating means is moved by a predetermined distance in the moving direction with respect to the substrate on which the magnetic sensor is mounted, an output value from the magnetic sensor corresponding to the moving distance in the moving direction is used. A position detection device that performs position detection.   The magnetic flux generation means is composed of a magnet having a laminated structure in which N and S poles are magnetized side by side in the moving direction, and two N and S poles are magnetized side by side in the vertical direction. The position detection device according to claim 1.   The magnetic flux generating means has an articulated structure in which N poles and S poles are magnetized side by side in the moving direction, and two N poles and S poles are magnetized side by side in a horizontal direction perpendicular to the moving direction. The position detection device according to claim 1, comprising a magnet.   A position detection device according to any one of claims 1 to 3, and a position detection mechanism of an image stabilization lens to which an output signal from the position detection device is input, an autofocus mechanism, or a zoom mechanism. An actuator characterized by.   The camera shake correction lens position detection mechanism, autofocus mechanism, or zoom mechanism is used as a camera shake correction lens position detection mechanism, autofocus mechanism, or zoom mechanism of a digital camera or mobile phone. The actuator according to claim 4.   The actuator according to claim 5, wherein the magnet includes an X-axis driving magnet and a Y-axis driving magnet.

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