JP2011221335A - Drive module and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive module suitable for detecting accurately the number of revolutions.SOLUTION: A method for manufacturing a drive module 1 comprising a stator 20, a rotor 10 with n (an integer number) projection parts 15, and a housing 39 storing the stator 20 and the rotor 10 includes the steps of: mounting a rotating member 40 having m blade parts 45 arranged at equal intervals with each other with m gap parts 44 therebetween, m being an integer multiple of n, on a shaft 19; and attaching a sensor 50 for detecting the blade parts 45 or the gap parts 44 at a position between the center 450 of a first blade part 45c and the end 41c of the forward direction 111 of the first blade part 45c, with the rotor 10 stopped, when directly or indirectly attaching the sensor 50 to the housing 39.

Description

  The present invention relates to a drive module and a manufacturing method thereof.

  Patent Document 1 absorbs the backlash of rotation that occurs due to the effects of the elasticity of components that constitute the speed reduction mechanism that is in the middle of transmitting the drive force of the drive motor to the driven part, and sets the rotation speed. It is described that an apparatus capable of accurately driving a photographing optical system by accurately counting is described. Therefore, in Patent Document 1, a skirt provided in the worm is fitted into a C-shaped hole of the PI blade, a motor shaft passes through each center, and a notch provided in the skirt and a PI blade are provided. It is described that the rotation of the worm is transmitted to the PI blade with a play of a predetermined angle by the action of the formed C-shaped hole.

JP 9-318333 A

  Some imaging devices such as digital cameras and mobile phone cameras move a lens group in the optical axis direction to realize an autofocus function and a zoom function, and a drive module including a DC motor is used as a drive source. ing. In order to move the lens group and stop it at a predetermined position with high accuracy, it is required to detect the rotation speed (rotation history) of the motor with high accuracy.

  One factor that causes indefinite rotation count is cogging torque. Depending on the timing and angle at which the rotor (rotor) is stopped, the motor may reversely stop due to the cogging torque, and the motor may erroneously count the number of rotations. Cogging indicates a phenomenon in which a magnetic attraction force between a stator (armature, stator) and a rotor (rotor) changes (pulsates) depending on a rotation angle in a motor. Cogging torque is generated by the influence of the position and shape of the stator and rotor, magnetic flux distribution, etc. When the power supply is stopped, the rotor generally has the smallest cogging torque near the angle where the power supply is stopped ( Stop at the minimum cogging torque position.

One aspect of the present invention is a method of manufacturing a drive module having a stator, a rotor having an integer n number of protrusions rotating inside the stator, and a housing containing the stator and the rotor. This method includes the following steps.
1. Rotation including m blades of a first width arranged on a shaft of a rotor in a circumferential direction at equal intervals from each other with m pieces of a first width of n integer multiples. Attaching the member (a step of attaching the rotating member).
2. When the sensor for detecting the blade portion or the gap portion is directly or indirectly attached to the housing, with the rotor stopped, between the center of the first blade portion and the forward end of the first blade portion, Alternatively, a sensor is attached at a position between the center of the first gap portion and the forward end of the blade portion adjacent to the first gap portion (step of attaching the sensor).

  In this drive module, the number of rotations of the rotor can be counted by alternately detecting the blades and / or the gaps of the rotating member that rotates in synchronization with the rotor. One case where an erroneous count occurs in this drive module is that the state of the sensor changes when the rotor is stopped due to cogging torque. On the other hand, a change in the state of the sensor when rotating forward (rotating in the forward direction) to the stop position by the cogging torque is unlikely to cause an erroneous count.

  The cogging torque is usually j times rotationally symmetric of an integral multiple of a motor including a rotor having n protrusions. Therefore, the maximum width (angle) reversed by the cogging torque is k times an integer multiple of k times, and includes k width rotational symmetry when reversed, and the two states of the blade portion and the gap portion are high. It is possible to arrange the blade portion and the gap portion so as to be rotationally symmetrical with each other m times so that the probability can be kept unchanged. For example, when the cogging torque is 6-fold rotationally symmetric in a motor including a rotor having three protrusions, the maximum width reversed by the cogging torque is approximately 12-fold rotationally symmetrical, and the blade portion and the gap portion In order to prevent the two states from changing, the blade portion and the gap portion are rotationally symmetrical with each other three times, and the sensor is reversed by providing an on / off region of the sensor with the six-fold rotationally symmetric blade portion or gap portion. It is possible to suppress erroneous counting due to.

  Therefore, in the process of attaching the sensor, in a state where the rotor is stopped, that is, in a state where the cogging torque is minimized, between the center of the first blade portion of the rotating member and the forward end of the first blade portion, Alternatively, the sensor is attached at a position between the center of the first gap portion and the forward end of the blade portion adjacent to the first gap portion. When the rotor rotates in the forward direction (forward rotation), the rotor rotates in the opposite direction (reverse rotation) due to the cogging torque and moves toward the stop position, but the reverse rotation range may be about half of the first width. Many. For this reason, by attaching the sensor to this position, even if the rotor rotates in the reverse direction due to the cogging torque, it is possible to suppress a change in the state in which the sensor blade or gap is detected.

  Therefore, it is possible to provide a drive module that can suppress erroneous counting of the number of forward rotations of the rotor and can control the stop position with higher accuracy. In addition, according to this manufacturing method, the center or end of the blade or gap of the rotating member can also be used as a Merckmar (index, mark) for mounting the sensor at a position where erroneous counting can be suppressed, and the stop position can be accurately Drive modules that can be well controlled can be manufactured more easily.

  Preferably, the step of attaching the sensor includes attaching the sensor to a circumferential center of the first blade portion or a circumferential center of the first gap portion. Sensors are mounted symmetrically in the clockwise and counterclockwise directions with respect to the blades or gaps. For this reason, when operating the drive module with either the clockwise direction or the counterclockwise direction as the forward direction, a drive module that can suppress erroneous counting due to reverse rotation caused by cogging torque and can control the stop position more accurately. Can be provided. Further, the center of each of the m blade portions and the m gap portions is Merckmar, and the position for attaching the sensor can be selected from 2m selectable positions. For this reason, a drive module with few erroneous counts can be manufactured efficiently and easily.

  Furthermore, the step of attaching the rotating member is performed in a state where the rotor is stopped and one end of one of the m blades in the circumferential direction and the circumference of any one of the n protrusions. It is desirable to include attaching the rotating member so that it is aligned with one end of the direction. By aligning the blades or gaps of the rotating member and the protrusions of the rotor, fluctuations in cogging torque due to attachment of the rotating member can be suppressed. For this reason, it is possible to provide a drive module with fewer erroneous counts.

  The housing includes an opening that is accessible to one end in the circumferential direction of any one of the n protrusions in a state where the rotor is stopped, and the step of attaching the rotating member is performed via the opening. The rotating member is attached so that the position of either one of the m blades in the circumferential direction of one of the blades matches the position of any one of the circumferentials of any one protrusion. It is desirable to include that. Using light such as laser light that passes through the opening, the position of either one of the blades on the outside of the housing and one of the protrusions on the inside of the housing can be accurately determined from the outside of the housing. Can be combined. A pin is inserted into the opening, and the rotating member is attached so that one of the circumferential ends of any one of the blades is aligned with one of the circumferential ends of any one protruding portion. This is one of alignment methods that can be easily implemented.

  The sensor is typically a photointerrupter including a light emitting element and a light receiving element that are arranged to face each other. When the sensor is attached, a blade portion or a gap portion passes between the light emitting element and the light receiving element. Install the sensor.

  One of the different aspects of the present invention includes a stator, a rotor having an integer n number of protrusions rotating inside the stator, a housing containing the stator and the rotor, a rotating member attached to the rotor, A drive module having a sensor for detecting a blade portion or a gap portion of the rotating member. The rotating member includes m blade portions having a first width that are arranged at equal intervals in the circumferential direction at intervals of n first integral multiples of m first width spaces. The sensor is in a state where the rotor is stopped, and between the center of any one of the plurality of blade portions and the forward end of the first blade portion, or any one of the plurality of gap portions. It is directly or indirectly attached to the housing so as to be located between the center of one of the first gap portions and the forward end of the blade portion adjacent thereto.

  This drive module is less likely to change the state of the sensor and the rotating member even if the rotor is stopped by the cogging torque when the rotor is stopped, and can suppress erroneous counting of the number of rotations of the rotor. Therefore, it is possible to provide a drive module with high rotational speed detection accuracy and high stop position accuracy.

  It is desirable that the sensor is attached so as to be located at the center in the circumferential direction of the first blade portion or at the center in the circumferential direction of the first gap portion. Even when the forward direction is clockwise or counterclockwise, erroneous counting of the number of rotations by the sensor can be suppressed.

  Preferably, the housing includes an opening that can access one end in the circumferential direction of any one of the n protrusions in a state where the rotor is stopped. When a pin is inserted into the opening, the pin contacts one of the circumferential ends of any one of the m blades and one of the circumferential ends of any one protruding portion. By doing this, it can be confirmed or adjusted that the blade portion or the gap portion of the rotating member is set at a position synchronized with the rotor.

  The sensor is typically a photointerrupter including a light emitting element and a light receiving element that are arranged to face each other, and the rotating member is configured so that a blade portion or a gap portion passes between the light emitting element and the light receiving element. It is desirable that it is attached.

  One of the different aspects of the present invention is a lens module including the drive module described above and a lens system that includes a plurality of lens groups and at least one of the plurality of lens groups is moved by the drive module. With the drive module that can accurately count the number of rotations of the rotor, a lens module that moves the lens group to a predetermined position with high accuracy can be provided. One of the different aspects of the present invention is a camera having the lens module described above and an image sensor that acquires an image formed by the lens module.

The figure which showed typically the outline | summary of the camera carrying a drive module. The perspective view which shows the outline | summary of a drive module. The figure which expanded the drive module to the main parts which comprise a drive module. IV-IV sectional drawing of the motor of the drive module shown in FIG. 3 (IV-IV cross section of FIG. 3). FIG. 5 is a VV cross-sectional view of the rotating member of the drive module shown in FIG. 3 (VV cross-section in FIG. 3). The figure which showed typically a mode that a rotating member was attached to the shaft of a rotor. The figure which showed a mode that the sensor was attached to a housing. It is the figure which showed the state just before a rotor stops, (a) is the figure which showed the inside of a motor typically, (b) was the figure which showed the state of the rotating member and the sensor typically. It is the figure which showed the state which the rotor stopped, (a) is the figure which showed the inside of a motor typically, (b) was the figure which showed the state of the rotating member and the sensor typically. It is the figure which showed the state just before a rotor stops, (a) is the figure which showed the inside of a motor typically, (b) was the figure which showed the state of the rotating member and the sensor typically. It is the figure which showed the state which the rotor stopped, (a) is the figure which showed the inside of a motor typically, (b) was the figure which showed the state of the rotating member and the sensor typically.

  FIG. 1 schematically shows an outline of a camera equipped with a drive module according to the present invention. The camera 100 includes a body 99 and a lens module 95 housed in the body 99. The lens module 95 includes a drive module (actuator) 1 and a lens system 90. The lens system 90 includes a first lens group 91 and a second lens group 92 including one or a plurality of lenses, a lens holder 96 that holds the first lens group 91, and a second lens group 92. And a cam barrel 98 that moves the lens holder 96 or 97 to the object side (front side) 100a, the image side (back side) 100b, and the like. The drive module 1 moves the first lens group 91 and / or the second lens group 92 in the direction of the optical axis via the cam cylinder 98 to perform zooming or focusing. The number of lens groups included in the lens module 95 may be one or three or more.

  The camera 100 includes an operation button 4, a control unit 3 that moves the first lens group 91 and / or the second lens group 92 to a predetermined position by moving the drive module 1 by the operation of the operation button 4 or other factors. The image pickup device 5 such as a CCD or CMOS that acquires an image formed by the lens module 95 and the LCD 6 that displays image data acquired by the image pickup device 5 are included.

  FIG. 2 shows an outline of the drive module 1. FIG. 3 shows a diagram in which the drive module 1 is developed into main parts constituting the drive module 1. The drive module 1 includes a motor 30, a rotating member 40 attached to a shaft (rotor shaft) 19 of the motor 30, and a sensor 50 attached to a housing 39 of the motor 30. The rotating member 40 is attached to the shaft 19 of the rotor 10 outside the housing 39. The sensor 50 is for detecting the number of rotations of the rotating member 40.

  FIG. 4 shows an IV-IV sectional view of the motor 30 (IV-IV section of FIG. 3). The motor 30 is an inner rotor type DC motor, and includes a stator (stator) 20, a rotor (rotor) 10 that rotates inside the stator 20, and a housing 39 that houses the stator 20 and the rotor 10. . The rotor 10 is a three-pole rotor, and a protrusion (teeth) whose three-fold symmetry (120-degree rotational symmetry) around the shaft 101 of the shaft 19 protrudes in the radial direction 120 orthogonal to the axial direction 110. , Magnetic pole, salient pole) portion 15 (15a to 15c). A typical projecting portion 15 is a laminate of electromagnetic steel plates that are ferromagnetic materials such as silicon steel plates and have a high magnetic permeability. The three protrusions 15a to 15c are arranged around the shaft 101 with an interval of about 120 degrees, and each protrusion 15a to 15c extends in the circumferential direction (counterclockwise direction 111 and clockwise direction 112). It includes bowl-shaped parts 12a to 12c. These three protrusions 15a to 15c have a symmetric shape and have a common configuration. Therefore, hereinafter, when a configuration common to the three projecting portions 15a to 15c is described, the configuration is described as the projecting portion 15. The same applies to other parts.

  A recess 18 is formed between the protrusions 15a and 15b, between the protrusions 15b and 15c, and between the protrusions 15c and 15a, and the three recesses 18 wind the rotor coil 16. It becomes a slot.

  The stator 20 disposed outside the rotor 10 is a stator having two slots, and includes field portions 21 a and 21 b disposed at a two-fold symmetry (180-degree rotational symmetry) around the shaft 101. Including. These two field portions 21a and 21b have a symmetric shape and have a common configuration. For this reason, hereinafter, the configuration common to the two field portions 21a and 21b will be described as the field portion 21. The same applies to other parts. A typical field portion 21 is a permanent magnet such as a ferrite magnet. The two field portions 21 are arranged so as to face each other in the direction of the shaft 101, that is, inward.

  The housing 39 that houses the rotor 10 and the stator 20 includes an opening 31. The opening 31 is provided with a predetermined portion of the housing 39 so as to be able to access the end 11a in the counterclockwise direction (one of the circumferential directions) 111 of any of the protrusions 15 (the protrusion 15a in FIG. 4) of the stopped rotor 10. In the position.

  FIG. 5 shows a VV cross-sectional view of the rotating member 40 (VV cross-section of FIG. 3). The rotating member 40 is attached to the shaft 19 outside the housing 39, and the rotating member 40 rotates in conjunction with the rotor 10 via the shaft 19. The rotating members 40 are spaced apart from each other by three gaps 44a to 44c having three first widths 49 in the circumferential direction 111 or 112 (counterclockwise 111 or clockwise 112 of the rotor 10). It includes three blade portions 45a to 45c having a first width 49 arranged at intervals. These blade portions 45a to 45c have a symmetric shape and a common configuration. Hereinafter, when a configuration common to the blade portions 45a to 45c is described, the blade portion 45 will be described. The same applies to the gaps 44a to 44c.

  The rotating member 40 may be integrally formed of a resinous material including the blade portion 45, or may be made of a metal such as aluminum. The three blade portions 45a to 45c are each formed in a fan shape having a central angle about the axis 101 of about 60 degrees. The gaps 44a to 44c are also fan-shaped (fan-shaped) having a central angle about the axis 101 of about 60 degrees. That is, gaps having a central angle of about 60 degrees are formed between the blade portions 45a and 45b, between the blade portions 45b and 45c, and between the blade portions 45c and 45a. The blade portions 45a to 45c and the gap portions 44a to 44c form a detection region having a uniform width (first width, length, circumferential length) 49 in which the sensor 50 is turned on and off in the circumferential directions 111 and 112. .

  The sensor 50 can count the number of rotations of the rotating member 40 by detecting the blade portion 45 or the gap portion 44 of the rotating member 40, and the rotating member 40 rotates in synchronization with the rotor 10. Thus, the number of rotations of the rotor 10 can be counted. The sensor 50 of this example is a photo interrupter including a light emitting element 51 and a light receiving element 52 that are arranged to face each other in the axial direction 110. The sensor 50 includes a light emitting unit 51a including a light emitting element 51 that emits detection light and a light receiving unit 52a including a light receiving element 52 that receives the detection light, and a space between the light emitting unit 51a and the light receiving unit 52a. The detection region 53 formed in the (gap, optical path) is attached to the housing 39 so that the blade portion 45 of the rotating member 40 passes through.

  The sensor 50 outputs an on or off signal when the detection region 53 has the blade portion 45, and outputs an off or on signal when the detection region 53 does not have the blade portion 45 and is the gap portion 44. Therefore, the number of rotations of the rotating member 40 can be counted by counting the repetition of the on / off signal output from the sensor 50 by the control unit 3 or the like, and as a result, the number of rotations of the rotor 10 can be counted.

  At that time, when the motor 30 is stopped, the rotor 10 is reversed by the cogging torque. For example, when the signal of the sensor 50 changes from on to off, the sensor 10 is driven when the rotor 10 is driven in the same direction as the forward direction. 50 outputs a signal from off to on again. Alternatively, when the rotor 10 is reversed by the cogging torque and the signal of the sensor 50 changes from OFF to ON, when the rotor 10 is driven in the same direction as the forward direction, the sensor 50 again outputs the ON to OFF signal. Output. When such a situation occurs, it causes an erroneous count. When the motor 30 is stopped, the rotor 10 rotates in the forward direction by cogging torque, and if the signal of the sensor 50 changes from on to off or from off to on, it does not change from the normal count. Don't be.

  The sensor 50 is not limited to a photo interrupter, and may be a reflective photo reflector that detects reflected detection light, an ultrasonic sensor, a magnetic sensor, a proximity sensor, or the like. The possibility of counting exists as above. These sensors 50 may be attached to the housing 39 indirectly via a camera base (not shown) to which the drive module 1 is attached, instead of being attached directly to the housing 39.

  FIG. 6 schematically shows how the rotating member 40 is attached to the rotor shaft 19 of the motor 30 when the drive module 1 is manufactured. The drive module 1 is a DC motor in which the number of magnetic poles (projections) 15 of the rotor 10 is three and the number of slots of the stator 20 is two. In general, in the case of a DC motor having three magnetic pole portions and two slots, when the cogging torque is generated with six-fold rotational symmetry, that is, with a period of 60 degrees, and the power supply is stopped, the rotor 10 is cogged. Stop when the torque is at a minimum, or when the cogging torque and the magnetic force or other force (gravity, etc.) by the permanent magnet are balanced. Therefore, the stop position of the rotor 10 exists in 6-fold rotational symmetry, that is, at a pitch of 60 degrees. A typical position where the rotor 10 stops is a position where any one of the magnetic pole portions (projecting portions) 15a to 15c of the rotor 10 and either the field portion 21a or 21b of the stator 20 are closest. FIG. 4 is an example of the stop position, and shows a state where the magnetic pole part 15a and the field part 21a of the stator 20 are stopped in the closest state (arrangement and position).

  In this example, the rotating member 40 provided with the three blade | wing parts 45a-45c is attached to this motor 30. FIG. That is, the motor 30 including the rotor 10 having the (n = 3) protrusions 15 is arranged at equal intervals from each other with the (m = 3) first width 49 gaps 44 therebetween. A rotating member 40 including (m = 3) blade portions 45 having a first width 49 is attached. Therefore, in this case, the integer m is 1 times the integer n, and the rotating member 40 includes blade portions 45 and gap portions 44 provided at equal intervals at a pitch of 60 degrees. When the cogging torque with 6-fold rotational symmetry, that is, a 60 ° period cogging torque changes approximately in a sine curve, the width (angle width) from the maximum to the minimum of the cogging torque is 30 degrees, and when the rotor 10 stops The maximum angle width that can be reversed by the cogging torque is 30 degrees.

  Therefore, depending on the sensitivity of the sensor 50, the blades 45 and the gaps 44 having a width of 60 degrees, which is twice the maximum width that can be reversed, are alternately provided on the rotating member 40. Even if the sensor 50 is located at the center of the blade portion 45 or the gap portion 44 in the circumferential direction, the driving of the rotor 10 is stopped, and even if the rotor 10 is reversely stopped by the cogging torque, the state of the sensor 50 is does not change. Considering only the case where the rotor 10 rotates in one direction, for example, the case where it rotates in the counterclockwise direction 111, at the position where the rotor 10 stops due to the cogging torque, a certain blade part, for example, the center in the circumferential direction of the blade part 45c It is desirable to set the sensor 50 so as to be between the end 41c in the counterclockwise direction 111 of the portion 45c. By setting the sensor 50 in this way, even when the sensitivity of the sensor 50 is not so high, the fluctuation of the signal of the sensor 50 (on-off change) due to the reverse rotation by the cogging torque when the rotor 10 is stopped is almost certainly ensured. Can be prevented. At a position where the rotor 10 stops due to the cogging torque, the sensor 50 is placed between a certain gap, for example, the center in the circumferential direction of the gap 44b and the end 41b in the counterclockwise direction 111 of the blade 45b adjacent thereto. Even if it is set, the fluctuation of the signal of the sensor 50 due to the reverse rotation can be prevented almost certainly.

  On the other hand, when the rotor 10 rotates with the counterclockwise direction 111 and the clockwise direction 112 as forward directions, respectively, a position where the rotor 10 stops due to the cogging torque is a certain blade part, for example, the circumferential center of the blade part 45c, or It is desirable to set the sensor 50 at the center in the circumferential direction of a certain gap, for example, the gap 44b. By setting the sensor 50 in this manner, even when the rotor 10 is rotated in the counterclockwise direction 111 or the clockwise direction 112 in the forward direction, the sensor 50 is caused by the reverse rotation due to the cogging torque when the rotor 10 stops. Can be suppressed with high probability.

  In general, the cogging torque generated in a motor including a rotor having n protrusions is an integer multiple of j-fold rotational symmetry. Therefore, the maximum width (angle) reversed by the cogging torque is approximately k (k = 2 × j) times rotationally symmetric, includes a width of k times rotationally symmetric, and has a blade portion not more than the width of j times rotationally symmetric. When the rotor 10 is stopped by attaching the sensor 50 at an appropriate position by arranging 45 and the gap 44 in rotational symmetry with respect to each other, typically (m = j / 2). It is possible to prevent the signal from fluctuating even if the rotation is reversed by the cogging torque.

  Further, in this example, the positions of the three blade portions 45a to 45c of the rotating member 40 are matched with the positions of the protruding portions 15a to 15c of the rotor 10, so that the rotating member 40 is stopped by the cogging torque of the rotor 10. So as not to have a major impact on Therefore, as shown in FIG. 6, with the rotor 10 stopped, the pin 70 is inserted into the opening 31 of the housing 39, and the end 41a of the blade portion 45a in the counterclockwise direction 111 and the counterclockwise direction 111 of the protruding portion 15a are inserted. The position (angle, phase) with the end 11a is matched. Thereafter, the rotary member 40 is press-fitted and attached to the shaft 19 (step of attaching the rotary member 40). The pin 70 may be in the form of a rod that can be inserted into the opening 31, and may be made of resin, metal, wood, or the like. By connecting the rotor 10 and the rotating member 40 with the pin 70 through the opening 31 of the housing 39, the rotor 10 and the rotating member 40 can be held at a position where the rotor 10 stops. Accordingly, there is an advantage that the position of the sensor with respect to the rotating member 40 can be easily determined in the process of attaching the next sensor.

  For this reason, in terms of aligning the blade portion 45 of the rotating member 40 and the protruding portion 15 of the rotor 10, the alignment is performed using light such as laser light transmitted through the opening 31 instead of the pin 70. However, it is desirable to use the pin 70 in that the movement of the rotor 10 and the rotating member 40 is fixed at a position where the rotor 10 stops.

  FIG. 7 schematically shows how the sensor 50 is attached directly or indirectly to the housing 39 of the motor 30. As described above, in a state where the rotor 10 is stopped, the sensor 50 is positioned such that the detection region 53 of the sensor 50 is located at a certain blade portion (first blade portion), for example, the center 450 in the circumferential direction of the blade portion 45c. 50 is attached to the housing 39 (step of attaching the sensor 50). As indicated by a broken line in FIG. 7, the sensor 50 may be attached so that the detection region 53 is located at a certain gap (first gap), for example, the center 440 in the circumferential direction of the gap 44b.

  By setting the sensor 50 in this way, as described above, when the rotor 10 is rotationally driven with the counterclockwise direction 111 and the clockwise direction 112 as the forward direction, the rotor 10 is rotated in the direction opposite to the forward direction by the cogging torque. Even if it rotates and stops, it can suppress that the state of the sensor 50 changes. Therefore, when counting the rotation speed of the rotor 10 using the sensor 50, it is possible to suppress the occurrence of erroneous counting and the rotation speed of the rotor 10 becoming unclear.

  For this reason, when the lens group included in the lens module 95 is moved using the drive module 1, the stop position of the lens group can be controlled with higher accuracy. Therefore, the lens module 95 with higher optical accuracy can be provided, and the camera 100 capable of acquiring a clearer image can be provided. In addition, it is possible to provide a projection lens module including the same drive module 1, and it is possible to provide an optical apparatus such as a projector that can project a clearer image.

  8 and 9 show the state of rotation of the rotor 10 and the rotating member 40. FIG. FIG. 10 and FIG. 11 show different states of rotation between the rotor 10 and the rotating member 40. 8 and 10 schematically show a state immediately after the power supply to the rotor coil 16 of the drive module 1 is stopped, that is, a state immediately before the rotor 10 stops. 9 and 11 schematically show a state in which the rotor 10 is stopped by the cogging torque.

  8A and 9A show the inside of the motor 30, and FIGS. 8B and 9B show the states of the rotating member 40 and the sensor 50. FIG. In this example, the motor 30 is driven with the counterclockwise direction 111 as the forward direction. Focusing on the protrusion 15c of the rotor 10, as shown in FIG. 9A, a position of 330 degrees in the clockwise direction 112 is a stop position due to the cogging torque of the rotor 10. On the other hand, as shown in FIG. 8A, when the power supply to the rotor coil 16 is stopped at a position of 305 degrees in the clockwise direction 112, the rotor 10 is rotated by 25 degrees in the clockwise direction 112 and stopped.

  As shown in FIG. 8B, the sensor 15 detects the blade 45c at the position where the protrusion 15c is 305 degrees clockwise. The blade portion 45c is half-width and 30 degrees is ensured, and the sensor 50 is set to be located at the center of the blade portion 45c at the stop position. For this reason, as shown in FIG. 9B, even if the protruding portion 15c returns to the position of 330 degrees in the clockwise direction 112, the sensor 50 detects the blade portion 45c, and the detection state of the sensor 50 does not change. . Therefore, even if the rotor 10 is reversely rotated when stopped by the cogging torque, the rotation speed of the rotor 10 is not erroneously counted by the sensor 50.

  The same applies to FIGS. 10 and 11. 10A and 11A show the inside of the motor 30, and FIGS. 10B and 11B show the state of the rotating member 40 and the sensor 50. FIG. Also in this example, the motor 30 is driven with the counterclockwise direction 111 as the forward direction. Focusing on the protrusion 15a of the rotor 10, as shown in FIG. 11A, a position of 270 degrees in the clockwise direction 112 is a stop position due to the cogging torque of the rotor 10. On the other hand, as shown in FIG. 10A, when the power supply to the rotor coil 16 is stopped at the position of 245 degrees in the clockwise direction 112, the rotor 10 is rotated by 25 degrees in the clockwise direction 112 and stopped.

  As shown in FIG. 10B, the sensor 50 detects the gap 44a at the position where the protrusion 15a is 245 degrees clockwise. The gap 44a has a half width of 30 degrees, and the sensor 50 is set to be located at the center of the gap 44a at the stop position. For this reason, as shown in FIG. 11B, even if the protrusion 15a returns to the position of 270 degrees in the clockwise direction 112, the sensor 50 detects the gap 44a and the detection state of the sensor 50 does not change. . Therefore, even if the rotor 10 is reversely rotated when stopped by the cogging torque, the rotation speed of the rotor 10 is not erroneously counted by the sensor 50.

  Thus, according to the method of manufacturing the drive module 1 including the step of attaching the rotating member shown in FIG. 6 and the step of attaching the sensor shown in FIG. 7, the rotor 10 is reversed and stopped by the cogging torque. Even in this case, it is possible to suppress the erroneous counting of the rotation speed of the rotor 10 and to manufacture and provide the drive module 1 that can accurately count the rotation speed. In addition, by mounting the drive module 1, it is possible to provide the lens module 95 that can control the stop position of the lens group with higher accuracy. Furthermore, by mounting such a lens module 95, it is possible to provide the camera 100 that can acquire a clearer image. The integers n and m are not limited to the three cases described above.

DESCRIPTION OF SYMBOLS 1 Drive module 10 Rotor, 15 Protrusion part, 20 Stator, 30 Motor 31 opening part, 39 Housing 40 Rotating member, 45 Blade | wing part, 50 Sensor, 70 Pin 100 Camera, 111 Counterclockwise direction, 112 Clockwise direction

Claims (13)

A method of manufacturing a drive module having a stator, a rotor having an integer n number of protrusions rotating inside the stator, and a housing housing the stator and the rotor,
The m blades of the first width arranged on the shaft of the rotor in the circumferential direction at equal intervals from each other with a gap portion of m pieces of the first integral multiple of n in the circumferential direction. Attaching a rotating member including a portion;
When the sensor for detecting the blade portion or the gap portion is directly or indirectly attached to the housing, the center of the first blade portion and the forward direction of the first blade portion are in a state where the rotor is stopped. Mounting the sensor at a position between the ends or between the center of the first gap and the forward end of the vane adjacent to the first gap. In claim 1,
Attaching the sensor includes attaching the sensor at a position in the circumferential center of the first blade portion or a position in the circumferential center of the first gap portion. In claim 1 or 2,
The rotation member is attached in the state in which the rotor is stopped, and one end of the circumferential direction of any one of the m blade portions and one protrusion of the n protrusion portions. Attaching the rotating member so as to be aligned with one circumferential end of the portion. In any of claims 1 to 3,
The housing includes an opening that can access any one of the circumferential ends of any one of the n protrusions in a state where the rotor is stopped;
The rotation member is attached through the opening by either one of the circumferential ends of any one of the m blades or the circumferential direction of any one of the protrusions. Attaching the rotating member so that it is aligned with one of the ends. In claim 4,
To attach the rotating member, a pin is inserted into the opening, and either one of the circumferential ends of any one of the blades and any one of the circumferential directions of the one protruding portion Attaching the rotating member so that it is aligned with the end of the surface. In any of claims 1 to 5,
The sensor is a photo interrupter including a light emitting element and a light receiving element arranged to face each other,
Attaching the sensor includes attaching the sensor such that the blade portion or the gap portion passes between the light emitting element and the light receiving element. The stator,
A rotor having an integer n number of protrusions rotating inside the stator;
A housing containing the stator and the rotor;
A rotating member attached to the rotor, wherein the first widths are arranged at equal intervals in the circumferential direction with a gap of m first widths of integer multiples of n. A rotating member including the m blade portions of
A sensor for detecting the blade portion or the gap portion, and with the rotor stopped, between the center of the first blade portion and the forward end of the first blade portion, or the first A drive module having a sensor directly or indirectly attached to the housing so as to be located between the center of the gap and the forward end of the vane adjacent to the first gap; In claim 7,
The driving module, wherein the sensor is attached so as to be positioned at a center of the first blade portion in the circumferential direction or a center of the first gap portion in the circumferential direction. In claim 7 or 8,
The housing includes a drive module including an opening that can access one of the circumferential ends of any one of the n protrusions in a state where the rotor is stopped. In claim 9,
When a pin is inserted into the opening, the pin is connected to either one of the circumferential ends of any one of the m blades and the circumferential direction of any one of the protrusions. A drive module that contacts either end. In any of claims 7 to 10,
The sensor is a photo interrupter including a light emitting element and a light receiving element arranged to face each other,
The rotating member is a drive module attached so that the blade part or the gap part passes between the light emitting element and the light receiving element. A drive module according to any of claims 7 to 11,
A lens module comprising a lens system including a plurality of lens groups, wherein at least one of the plurality of lens groups is moved by the drive module. The lens module according to claim 12,
A camera having an image sensor for acquiring an image formed by the lens module;

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