JP6053650B2 - Position detecting device, lens device, and imaging device for movable optical element for imaging - Google Patents

Description

  The present invention relates to a position detection device for an imaging movable optical element, a lens device including the same, and an imaging device.

  In recent years, with the increase in resolution of solid-state imaging devices such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, digital still cameras, digital video cameras, mobile phones (including smartphones), PDAs (Personal). The demand for information devices having an imaging module such as a digital assistant (mobile information terminal) is rapidly increasing. Note that an information device having the imaging module as described above is referred to as an imaging device.

  In the imaging module of the imaging apparatus, a magnetic position detector (encoder) is used to detect the position of a movable optical element such as a movable lens.

  Encoders are roughly classified into incremental type encoders and absolute type encoders. The incremental encoder can detect with high resolution how much the movable optical element has moved from the position of the movable optical element when the imaging module is powered on. However, the absolute position of the movable optical element when the power is turned on cannot be detected. On the other hand, the absolute encoder can detect the absolute position of the movable optical element, but has a low detection resolution.

  Until now, an encoder combining an incremental encoder and an absolute encoder has been proposed (see Patent Document 1). If such an encoder is applied to an imaging module, the position of the movable optical element can be detected at high speed and with high accuracy. can do. In particular, in a commercial lens device such as a broadcast lens or a movie lens, it is desired that the position of the movable optical element can be detected at high speed and with high accuracy.

JP-A-6-203285

  Since the encoder mounted on the imaging device is required to be downsized, the width of the rotating body that is magnetized for incremental and the rotating body that is magnetized for absolute is reduced in the rotation axis direction. There is a need to. For this reason, as described in Patent Document 1, in the configuration in which two narrow rotating bodies are fitted to a thin rotating shaft, it is difficult to accurately assemble the rotating body perpendicularly to the rotating shaft. If the rotating body is not perpendicular to the rotation axis, an error occurs in the magnetic signal detected from the rotating body, and the position detection accuracy of the movable optical element is lowered.

  The present invention has been made in view of the above circumstances, and includes a position detection device for an imaging movable optical element capable of detecting the position of the imaging movable optical element with high accuracy and an imaging apparatus having the position detection device. The purpose is to provide.

  An imaging movable optical element position detection apparatus according to the present invention includes a rotating shaft fixed to a gear that rotates in conjunction with the movement of the imaging movable optical element, a cylindrical rotating body fixed to the rotating shaft, In the rotating body, a first magnetized portion provided on one end surface in the axial direction in which the rotating shaft extends, a first magnetic detection element facing the first magnetized portion, and a side surface of the rotating body, A second magnetizing portion provided along a circumferential direction of the rotating body, and a second magnetic detection element facing the second magnetizing portion, and the rotating body is disposed on the rotating shaft. The first rotating body to be fitted and the second rotating body to be fitted to the first rotating body, and the first rotating body or the second rotating body has the first rotating body. A magnetized portion is provided, and the second magnetized portion is provided on the second rotating body or the first rotating body, and the first rotating body is provided. The body has a cylindrical first rotating part through which the rotating shaft is inserted, and a cylindrical first rotating part protruding from the axial end surface of the first rotating part in the axial direction and through which the rotating shaft is inserted. An area when the second rotating part is viewed from the axial direction is smaller than an area when the first rotating part is viewed from the axial direction, and the second rotating body is Is fitted to the second rotating part of the first rotating body, between the first rotating body and the second rotating body in the axial direction, and the first rotating body. And a magnetic shield provided on a side surface along the rotation direction of the rotating body on which the first magnetized portion is provided in the second rotating body.

  The lens device of the present invention includes the position detection device for the imaging movable optical element and a focus lens or a zoom lens as the imaging movable optical element.

  An imaging device of the present invention includes the lens device and an imaging device that images a subject through the imaging movable optical element.

  ADVANTAGE OF THE INVENTION According to this invention, the position detection apparatus of the movable optical element for imaging which can perform the position detection of the movable optical element for imaging with high precision, and the imaging apparatus which has this position detection apparatus can be provided.

1 is a schematic cross-sectional view showing a schematic configuration of a position detecting device 100 for an imaging movable optical element according to an embodiment of the present invention. The figure for demonstrating the magnetized part 5a and the magnetized part 6a shown in FIG. Cross-sectional schematic diagram showing a schematic configuration of a position detection device 200 which is a modification of the position detection device 100 Cross-sectional schematic diagram showing a schematic configuration of a position detection device 300 which is a modification of the position detection device 100 Cross-sectional schematic diagram showing a schematic configuration of a position detection device 400 which is a modification of the position detection device 100 Cross-sectional schematic diagram showing a schematic configuration of a position detection device 500 which is a modification of the position detection device 100 Cross-sectional schematic diagram showing a schematic configuration of a position detection device 600 which is a modification of the position detection device 100 Cross-sectional schematic diagram showing a schematic configuration of a position detection device 700 which is a modification of the position detection device 100

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a position detection device 100 for an imaging movable optical element according to an embodiment of the present invention.

  The position detection device 100 includes a lens unit as a lens device including a zoom lens for changing a focal length, a focus lens for changing a focal position, and a movable optical element for imaging such as a diaphragm for adjusting a light amount, or This lens unit is mounted on a removable imaging device. The imaging device includes an imaging element that images a subject through a movable optical element in the lens unit.

  The position detection device 100 includes a movable part that rotates in conjunction with the movement of the movable optical element mounted on the lens unit, and a fixed part that has a fixed position regardless of the movement of the movable optical element.

  The movable part includes a rotating shaft 3 fixed to the gear 4 that rotates in conjunction with the movement of the movable optical element, and a rotating body 8 fixed to the rotating shaft 3.

Fixing unit includes a substrate 12, a dome-shaped protective case 1 fixed to the substrate 12, a bearing 2 which is fixed to the protective case 1, a magnetic detection element 9, 10 and the substrate 11 provided in the protective case 1 .

  The rotating shaft 3 includes a cylindrical large diameter portion 3a and a small diameter portion 3b arranged on the same axis. The large diameter portion 3a has a so-called stepped structure in which the outer diameter when viewed from the direction in which the rotating shaft 3 extends (hereinafter referred to as the axial direction) is larger than that of the small diameter portion 3b. The rotating shaft 3 is made of metal, for example.

The gear 4 is fixed to the rotating shaft 3 outside the protective case 1, and rotates the rotating shaft 3 by rotating in conjunction with the movement of a movable optical element (not shown). The gear 4 has a cylindrical shape. In the example of FIG. 1, the gear 4 and the rotary shaft 3 are fixed by fitting the large-diameter portion 3 a of the rotary shaft 3 into the hollow portion of the gear 4.

  The bearing 2 supports the rotating shaft 3 rotatably between the gear 4 and the rotating body 8, and is made of, for example, oilless metal.

Bearing 2 is fixed to the protective case 1 to the outer edge portion is fitted in a bearing hole provided in the protective case 1. A small diameter portion 3b of the rotary shaft 3 is inserted into a hollow portion of the bearing 2, and the bearing 2 rotatably supports the small diameter portion 3b of the rotary shaft 3 in the hollow portion. In the example of FIG. 1, the end face on the gear 4 side in the axial direction of the bearing 2 is in contact with the large diameter portion 3 a of the rotating shaft 3. The rotary shaft 3 and the bearing 2 are selected from materials that are less worn when rubbed against each other.

  The rotating body 8 includes a rotating body 5 fitted to the small diameter portion 3 b of the rotating shaft 3, a rotating body 6 fitted to the rotating body 5, and a magnetic shield 7.

  The rotating body 5 includes a cylindrical large-diameter portion 5b (first rotating portion) through which the small-diameter portion 3b of the rotating shaft 3 is inserted, and an axial direction from the end surface in the axial direction of the large-diameter portion 5b. And a cylindrical small-diameter portion 5c (second rotating portion) that protrudes on the opposite side and into which the small-diameter portion 3b of the rotating shaft 3 is inserted.

  The outer diameter when viewed from the axial direction of the large diameter portion 5b is larger than the outer diameter when viewed from the axial direction of the small diameter portion 5c. That is, the area when the small diameter portion 5c is viewed from the axial direction is smaller than the area when the large diameter portion 5b is viewed from the axial direction. In addition, if the area when the small diameter portion 5c is viewed from the axial direction is smaller than the area when the large diameter portion 5b is viewed from the axial direction, the small diameter portion 5c is not a cylinder but a square tube, an elliptic cylinder, or the like. Another cylindrical shape may be sufficient.

  A concave portion 5d is formed on the end surface of the large diameter portion 5b of the rotating body 5 on the bearing 2 side in the axial direction, and the end portion of the bearing 2 bites into the concave portion 5d. The rotating body 5 and the bearing 2 are made of a material that hardly wears between them. In FIG. 1, it is assumed that there is a very small gap of, for example, about 0.1 mm between the bearing 2 and the large-diameter portion 5 b of the rotating body 5 in the axial direction, but this gap may be completely eliminated. .

  The rotating body 6 has a cylindrical shape, and the small-diameter portion 5c of the rotating body 5 is fitted in the hollow portion.

  On the side surface of the large-diameter portion 5b of the rotating body 5, a magnetized portion 5a in which magnetism is recorded is provided along the circumferential direction of the large-diameter portion 5b. In addition, a magnetized portion 6a in which magnetism is recorded is provided on the end surface of the rotating body 6 in the axial direction (the side opposite to the bearing 2 side).

  FIG. 2 is a diagram for explaining the magnetized portion 5a and the magnetized portion 6a shown in FIG. Fig.2 (a) is the figure which expand | deployed the magnetized part 5a formed in the side surface of the large diameter part 5b in the circumferential direction. FIG. 2B is a front view of the rotating body 8 when viewed from the axial direction.

  As shown in FIG. 2 (a), the magnetized portion 5a has a large number of alternating S poles (areas with "S" in the figure) and N poles (areas with "N" in the figure). (For example, 100 pieces) are arranged at a predetermined magnetization pitch.

  As shown in FIG. 2 (b), the magnetized portion 6a divides the end face of the rotating body 6 into two regions in the rotational direction of the rotating body 6, with one region having an S pole ("S" in the figure). An area) is formed, and an N pole (an area with “N” in the figure) is formed in the other region. In the magnetized portion 6a, the magnetization pitch in the rotation direction of the rotating body 6 is sufficiently larger than the magnetization pitch of the magnetized portion 5a.

Returning to the description of FIG. 1, the substrate 12 to which the protective case 1 is fixed is provided with a magnetic detection element 9 as a second magnetic detection element at a position facing the magnetized portion 5 a provided in the rotating body 5.

  Moreover, the board | substrate 11 is formed in the internal peripheral surface of the edge part 1b on the opposite side to the edge part in which the bearing hole is provided among the both ends in the axial direction of the protective case 1. FIG. On the substrate 11, a magnetic detection element 10, which is a first magnetic detection element, is provided so as to face the magnetized portion 6 a provided in the rotating body 6.

  In the protective case 1, the end portion 1b and the other portion 1a are separate, and the protective case 1 is completed with the end portion 1b attached to the portion 1a.

  Each of the magnetic detection elements 9 and 10 includes two magnetoresistive effect elements whose electric resistance changes according to an applied magnetic field, and outputs a voltage signal corresponding to the electric resistance as a detection signal. The magnetic detection elements 9 and 10 are each configured to output two voltage signals that are out of phase.

  While the rotator 8 rotates at an angle (for example, 360 °) corresponding to the movable distance of the movable optical element, the magnetic detection element 10 generates a first pulse that changes in a sine wave shape and a first pulse For example, a second pulse having a phase difference of 90 ° is output. The relationship between the level ratio of the first pulse and the second pulse at an arbitrary time point and the rotation angle of the rotating body 8 is known. For this reason, based on the detection signal of the magnetic detection element 10, the rotation angle of the rotating body 8, that is, the absolute position of the movable optical element can be detected.

  Further, while the rotator 8 rotates at an angle corresponding to the magnetization pitch of the magnetized portions 5a, the magnetic detection element 9 generates, for example, a third pulse that changes in a sinusoidal shape and a third pulse. A fourth pulse with a 90 ° phase shift is output. By comparing the third pulse and the fourth pulse, it is possible to detect whether the rotation direction of the rotating body 8 is normal rotation or reverse rotation. In addition, by counting the number of the third pulse or the fourth pulse, how much the rotating body 8 is rotated from the power-on position of the imaging apparatus, that is, the movable optical element is the power-on position of the imaging apparatus. It is possible to detect how much has moved.

  Therefore, based on the detection signal of the magnetic detection element 10, the absolute position of the movable optical element when the power is turned on is detected with rough accuracy, and how much the movable optical element has moved in which direction from the absolute position. By detecting with high resolution based on the detection signal of the magnetic detection element 9, the position of the movable optical element can be detected with high accuracy.

  The position detection device 100 includes a position detection unit (not shown) that detects the position of the movable optical element based on the detection signal of the magnetic detection element 10 and the detection signal of the magnetic detection element 9, and this position detection unit is protected. Provided on the substrate 12 outside the case 1.

  The rotating body 5 and the magnetic detection element 9 are the same as the hardware configuration of a so-called incremental encoder, and the rotating body 6 and the magnetic detection element 10 are the same as the hardware configuration of a so-called absolute encoder.

  The configurations of the magnetized portion 5a and the magnetic detection element 9 in the rotating body 5 can adopt the same hardware configuration as that of a known incremental encoder, and are not limited to those described above. Further, the configuration of the magnetized portion 6a and the magnetic detection element 10 in the rotating body 6 can adopt the same hardware configuration as that of a known absolute encoder, and is not limited to that described above.

  The magnetic shield 7 is provided on the side surface along the rotation direction of the rotating body 6 and on the end surface opposite to the end surface on which the magnetized portion 6 a is provided, of both end surfaces in the axial direction of the rotating body 6.

  Generally, a magnet having a strong magnetic force such as a neodymium magnet is used for an absolute encoder. Incremental encoders use weak magnets such as ferrite magnets. Also in the position detecting device 100, a strong magnetic force is emitted from the magnetized portion 6a, and a weak magnetic force is emitted from the magnetized portion 5a. For this reason, the magnetic shield 7 is provided in order to prevent the magnetic detection element 9 from being affected by the strong magnetic field from the magnetized portion 6a.

  The magnetic shield 7 should just be comprised with the member which cannot permeate | transmit a magnetic field or can weaken a magnetic field, For example, the same metal as the rotating shaft 3 etc. can be used.

  The position detection apparatus 100 configured as described above is manufactured as follows.

  First, the portion 1a of the protective case 1 is fixed to the substrate 12 on which the magnetic detection element 9 is formed, and the bearing 2 is press-fitted into the bearing hole of the portion 1a to fix the bearing 2 to the portion 1a.

  Next, a rotating body 6 in which the magnetic shield 7 is assembled on the side surface and the end surface is prepared, and the small diameter portion 5c of the rotating body 5 is press-fitted into the hollow portion of the rotating body 6 to obtain the rotating body 8.

  Next, the small diameter part 3b of the rotating shaft 3 is inserted into the bearing 2 from the outside of the protective case. Then, the small diameter portion 3 b of the rotating shaft 3 is press-fitted into the hollow portion of the rotating body 5 with the large diameter portion 3 a of the rotating shaft 3 pressed against the end surface of the bearing 2.

  Next, the substrate 12 on which the magnetic detection element 9 is mounted is brought into close contact with the rotating body 5 while observing the output waveform of the magnetic detection element 9 and bonded and fixed to the protective case 1 at an appropriate position. Next, the end portion 1b on which the substrate 11 and the magnetic detection element 10 are formed is adhered to the protective case 1 at an appropriate position while approaching the rotating body 6 while viewing the output waveform of the magnetic detection element 10.

  In the position detection device 100 thus obtained, the large diameter portion 3a of the rotating shaft 3 is press-fitted into the hollow portion of the gear 4 in the lens unit assembling process.

  According to the position detection device 100 described above, even if the imaging device incorporating the position detection device 100 moves violently, the rotation shaft 3 and the bearing 2 are separated from each other by the large diameter portion 3 a of the rotation shaft 3. The relative movement can be made only by the gap between the two. That is, the large diameter portion 3a of the rotating shaft 3 functions as a restricting portion that restricts relative movement of the rotating shaft 3 and the bearing 2 in the axial direction.

  For this reason, by setting the gap between the bearing 2 and the rotating body 5 to a minute value that does not affect the output of the magnetic detection element 10 even when the gap fluctuates, the bearing 2 and the rotary shaft 3 are It is possible to prevent a decrease in absolute position detection accuracy due to relative movement and fluctuations in the output of the magnetic detection element 10. With this configuration, output adjustment of the magnetic detection element 10 is not necessary, so that the manufacturing cost of the position detection device 100 can be reduced.

  Moreover, according to the position detection apparatus 100, since the output fluctuation | variation of the magnetic detection element 10 is suppressed, it becomes possible to use a thing with high resolution as the magnetic detection element 10, and raises the position detection precision of a movable optical element. be able to.

  In addition, according to the position detection device 100, the large diameter portion 3 a of the rotating shaft 3 is fitted to the gear 4, and therefore the gear 4 is rotated as compared with the configuration in which the thin shaft is fitted to the gear 4. It can be stably assembled to the shaft 3. As a result, the reliability of the apparatus can be improved.

  In the position detection device 100 mounted on the imaging device, it is required to minimize the distance between the bearing 2 and the rotating body 5 in the axial direction and the distance between the gear 4 and the bearing 2 in the axial direction for miniaturization. . When the rotating shaft 3 is not a stepped structure, that is, when the diameter of the large diameter portion 3a is the same as that of the small diameter portion 3b in FIG. 1, if the distance between the gear 4 and the bearing 2 is reduced, the rotating shaft When the shaft 3 and the bearing 2 move relative to each other in the axial direction, the gear 4 and the bearing 2 come into contact with each other, and the gear 4 is worn, leading to a decrease in the reliability of the position detection device.

  According to the position detection device 100, even if the distance between the gear 4 and the bearing 2 is reduced to such an extent that they do not come into contact with each other, when the rotary shaft 3 and the bearing 2 move relative to each other in the axial direction, The gear 4 and the bearing 2 do not come into contact with each other due to the barrier 3a. Therefore, wear of the gear 4 can be prevented and deterioration of the reliability of the apparatus can be prevented.

  In addition, when providing a clearance gap between the bearing 2 and the rotary body 5, if the rotary shaft 3 and the bearing 2 move relatively in an axial direction, the bearing 2 and the rotary body 5 will contact. However, by selecting a material that does not easily wear even when both are rubbed, the reliability of the apparatus can be prevented from being lowered. On the other hand, what kind of gear 4 is used for each model of the imaging apparatus is determined, and a material that is easily worn by friction is usually used. For this reason, it is difficult to change the material of the gear 4 to a material that does not easily wear due to contact with the bearing 2. For this reason, in the position detection apparatus 100, it is effective to provide the large-diameter portion 3a that functions as a restricting portion.

  Further, in the position detection device 100, it is difficult to increase the length of the rotating body 8 in the axial direction due to miniaturization. Therefore, in the configuration in which the rotator provided with the incremental magnetized portion and the rotator provided with the absolute magnetized portion are individually fitted to the rotary shaft 3, the axial length of each rotator is set. It is necessary to make it small, and it is difficult to stably fit each rotating body to the rotating shaft 3.

  According to the position detection device 100, the rotating body 5 provided with the incremental magnetizing portion 5a and the rotating body 6 provided with the absolute magnetizing portion 6a are not individually fitted to the rotating shaft 3, respectively. Only the rotating body 5 is fitted to the rotating shaft 3, and the rotating body 6 is fitted to the rotating body 5.

  For this reason, the length of the fitting part with the rotating shaft 3 in the rotating body 5 can be enlarged, and the rotating body 5 can be stably fitted also to the thin part of the rotating shaft 3. Further, since the rotating body 6 is fitted to the small diameter portion 5c having a diameter larger than that of the rotating shaft 3, the rotating body 6 having a smaller length in the axial direction is rotated as compared with the case where the rotating body 6 is directly fitted to the rotating shaft 3. The body 6 can be stably fitted to the rotating body 5.

  As a result, the positional relationship between the magnetized portion 5a provided on the rotating body 5 and the magnetic detecting element 9 and the positional relationship between the magnetized portion 6a provided on the rotating body 6 and the magnetic detecting element 10 can be made as designed. Therefore, it is possible to prevent the position detection accuracy of the movable optical element from being lowered.

  Further, the position detection device 100 has a configuration in which a concave portion 5d is provided on the end surface of the rotating body 5, and a part of the bearing 2 bites into the concave portion 5d. For this reason, compared with the case where this recessed part 5d is not provided, the axial direction length of the position detection apparatus 100 can be made small, and size reduction is attained.

  In the configuration in which the rotating body provided with the incremental magnetizing portion and the rotating body provided with the absolute magnetizing portion are individually fitted to the rotating shaft 3, the rotating body provided with the incremental magnetizing portion is provided. The axial length is reduced. For this reason, if the recessed part 5d is provided in this rotary body, the attachment precision of this rotary body will fall. According to the position detection device 100, since the length of the fitting portion of the rotating body 5 with the rotating shaft 3 is large, it is possible to prevent the mounting accuracy of the rotating body 5 from being lowered even if the recess 5d is provided. Thus, both downsizing and prevention of deterioration in position detection accuracy can be achieved.

  Normally, the gear 4 and the rotary shaft 3 are made of different materials. However, when a rolling bearing is used as the bearing 2, the rotary shaft 3 can be made of the same material as the gear 4.

  The rolling bearing includes a rotatable inner peripheral part (including a hollow part), an outer peripheral part provided outside the inner peripheral part, and a rolling part between the inner peripheral part and the outer peripheral part. When the bearing 2 is a rolling bearing, the outer peripheral portion is fixed to the protective case 1 and the inner peripheral portion is rotatable. For this reason, if the diameter of the large diameter part 3a of the rotating shaft 3 is larger than the diameter of the hollow part in the inner peripheral part of the rolling bearing and equal to or less than the diameter of the inner peripheral part, the rotating shaft 3 is made of the same material as that of the gear 4. Even if it comprises, since the rotating shaft 3 and the bearing 2 rotate together, the abrasion of the rotating shaft 3 can be prevented.

  In the rotating body 8 of the position detecting device 100, the diameter of the small diameter portion 5c of the rotating body 5 may be larger than the diameter of the small diameter portion 3b of the rotating shaft 3, but in the direction orthogonal to the axial direction of the rotating body 8. In order to prevent the length from becoming large, it is preferable that the length is not more than half of the diameter of the rotating body 6.

  In the position detection device 100, the diameter of the large-diameter portion 3 a of the rotating shaft 3 is preferably smaller than the diameter of the outer peripheral portion of the bearing 2. Thereby, it can prevent that the diameter of the gear 4 fitted with the large diameter part 3a of the rotating shaft 3 becomes large.

  In the above description, the large-diameter portion 3a of the rotating shaft 3 has a cylindrical shape, but the rotation center of the rotating shaft 3 may be the same as the rotation center of the gear 4 as a whole. And a columnar shape including an elliptical column. When the large-diameter portion 3a has a columnar shape, the length in one direction orthogonal to the axial direction of the large-diameter portion 3a is greater than the length in one direction of the portion (hollow portion) that supports the rotating shaft 3 of the bearing 2. If it is, this large diameter part 3a can be functioned as a restricting part. Moreover, the diameter of the gear 4 can be prevented from increasing by making the length of the large diameter portion 3a in the one direction smaller than the length of the outer peripheral portion of the bearing 2 in the one direction.

  Hereinafter, modifications of the position detection device 100 will be described.

  FIG. 3 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device 200 that is a modification of the position detection device 100.

  The position detection device 200 has the same configuration as the position detection device 100 except that the rotation shaft 3 is changed to the rotation shaft 3A and the restriction unit 13 is added.

  The rotating shaft 3A is a shaft having a constant diameter in the axial direction.

  The restricting portion 13 is fixed to the rotating shaft 3A between the gear 4 fixed to the rotating shaft 3A and the bearing 2 through which the rotating shaft 3A is inserted. The restricting portion 13 is a cylindrical member, and is fixed to the rotating shaft 3A by fitting the rotating shaft 3A into the hollow portion. The restricting portion 13 is in contact with the gear 4 and the bearing 2, and fulfills a function of restricting relative movement of the rotating shaft 3 </ b> A and the bearing 2 in the axial direction.

  The restricting portion 13 is made of a material different from that of the gear 4. As a material of the restricting portion 13, a material that does not wear even if it rubs against the bearing 2 may be selected.

  As described above, according to the position detection device 200, the restriction portion 13 provided separately from the rotation shaft 3A can suppress the variation in the distance between the rotation body 8 and the magnetic detection element 10. It is possible to prevent a decrease in element position detection accuracy.

  Even in the position detection device 200, if a rolling bearing is used as the bearing 2, the restriction unit 13 can select the same material as that of the gear 4.

  Moreover, in the position detection apparatus 200, when the material of the control part 13 and the rotating shaft 3A is the same, the control part 13 and the rotating shaft 3A may be integrated.

  Further, similarly to the large-diameter portion 3a in FIG. 1, the restricting portion 13 only needs to have a length in one direction orthogonal to the axial direction larger than the length in the one direction of the hollow portion of the bearing 2.

  FIG. 4 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device 300 that is a modification of the position detection device 100.

  The position detection device 300 has the same configuration as the position detection device 100 of FIG. 1 except that the rotary body 8 is changed to a rotary body 8A. The rotating body 8A has the same configuration as the position detection device 100 except that the rotating body 5 is the rotating body 5A and the rotating body 6 is the rotating body 6A.

  The rotating body 5A is obtained by changing the small diameter portion 5c of the rotating body 5 into a small diameter portion 5cA that is tapered in the protruding direction. The rotating body 6A is obtained by changing the hollow portion of the rotating body 6 into a shape corresponding to the small diameter portion 5cA.

  According to this configuration, the rotating body 5A and the rotating body 6A can be easily fitted, and the manufacturing efficiency of the apparatus can be increased. Also, the assembly accuracy of the rotating body 5A and the rotating body 6A can be improved.

  FIG. 5 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device 400 that is a modification of the position detection device 100.

  The position detecting device 400 has the same configuration as the position detecting device 100 except that the rotating body 8 is changed to the rotating body 8B.

  The rotating body 8B includes a rotating body 6B fitted to the small diameter portion 3b on the opposite side to the gear 4 with respect to the bearing 2, and a rotating body 5B fitted to the rotating body 6B. And a magnetic shield 7.

  The rotating body 6B includes a cylindrical large-diameter portion 6b (first rotating portion) through which the small-diameter portion 3b of the rotating shaft 3 is inserted, and an axial end (bearing 2 side) from the end surface in the axial direction of the large-diameter portion 6b. A cylindrical small-diameter portion 6c (second rotating portion) that protrudes and through which the small-diameter portion 3b of the rotating shaft 3 is inserted.

  The outer diameter when viewed from the axial direction of the large diameter portion 6b is larger than the outer diameter when viewed from the axial direction of the small diameter portion 6c. That is, the area when the small diameter portion 6c is viewed from the axial direction is smaller than the area when the large diameter portion 6b is viewed from the axial direction. In addition, if the area when the small diameter portion 6c is viewed from the axial direction is smaller than the area when the large diameter portion 6b is viewed from the axial direction, the small diameter portion 6c is not a cylinder but a rectangular tube or an elliptical tube. Another cylindrical shape may be sufficient.

  A recess 6d is formed in the end surface on the bearing 2 side in the axial direction of the small diameter portion 6c of the rotating body 6B, and the end of the bearing 2 bites into the recess 6d. The rotating body 6B and the bearing 2 are made of a material that hardly wears between them. In FIG. 5, in the axial direction, there is a very small gap of about 0.1 mm between the bearing 2 and the small diameter portion 6c of the rotating body 6B. However, this gap may be completely eliminated.

  The rotating body 5B is cylindrical, and the small-diameter portion 6c of the rotating body 6B is fitted in the hollow portion.

  A magnetized portion 5a is provided on the side surface of the rotating body 5B along the circumferential direction of the rotating body 5B. Moreover, the magnetized part 6a is provided in the end surface in the axial direction (the opposite side to the bearing 2 side) of the rotary body 6B.

  The magnetic shield 7 is provided on the side surface of the rotating body 6B and the end surface opposite to the end surface on which the magnetized portion 6a is provided, of both end surfaces in the axial direction of the rotating body 6B.

  As described above, the rotating body 6B provided with the magnetized portion 6a is directly fitted to the rotating shaft 3, and the rotating body 5B is fitted to the rotating body 6B. 3 can stably assemble the rotating body 8B.

  Further, according to the position detection device 400 of FIG. 5, the length in the direction perpendicular to the axial direction of the small diameter portion 6c of the rotating body 6B is set to the small diameter portion in the position detection device 100 of FIG. 1 without changing the size of the device. It is possible to make it larger than 5c (see FIG. 7 described later). For this reason, it is possible to further reduce assembly errors when fitting the rotating body 5B to the rotating body 6B.

  FIG. 6 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device 500 that is a modification of the position detection device 100.

  The position detecting device 500 is the same as the position detecting device 400 of FIG. 5 except that the rotating body 5B is changed into a rotating body 5C and the rotating body 6B is changed into a rotating body 6C. It is the same configuration.

  The rotating body 6C is obtained by changing the small diameter portion 6c of the rotating body 6B to a small diameter portion 6cA that is tapered in the protruding direction. The rotating body 5C is obtained by changing the hollow portion of the rotating body 5B into a shape corresponding to the small diameter portion 6cA.

  According to this configuration, the rotating body 5C and the rotating body 6C can be easily fitted, and the manufacturing efficiency of the apparatus can be increased. Moreover, the assembly accuracy of the rotating body 5C and the rotating body 6C can be improved.

  FIG. 7 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device 600 that is a modification of the position detection device 100.

  The position detection device 600 has the same configuration as the position detection device 400 shown in FIG. 5 except that the rotating body 6B is changed to the rotating body 6D and the magnetic shield 7 is changed to the magnetic shield 7A.

  The rotating body 6D has a constant diameter in the axial direction of the rotating body 6B in FIG. 7 A of magnetic shields are provided in the end surface of the rotary body 5B, and the non-contact surface with the rotary body 5B among the side surfaces of the rotary body 6D.

  Thus, even if the rotating body that is directly fitted to the rotating shaft 3 does not have a stepped structure, the two rotating bodies constituting the rotating body 8D can be prevented from being inclined with respect to the rotating shaft. .

  In FIG. 1, the diameter of the rotating body 5 may be constant in the axial direction, and the rotating body 6 may be fitted to a part of the rotating body 5. However, in this configuration, since it is necessary to increase the diameter of the rotating body 6, the configuration shown in FIG. 7 is desirable from the viewpoint of miniaturization.

  As described above, the position detection device shown in FIGS. 4 to 7 can also apply the configuration of the rotating shaft 3 </ b> A and the restricting portion 13 shown in FIG. 3.

  Up to this point, the position detection device having the large-diameter portion 3a as the rotation shaft 3 or the one having the restriction portion 13 has been described. However, for example, even in the configuration shown in FIG. 8 in which the restricting portion 13 is deleted in FIG.

  As described above, the following items are disclosed in this specification.

  The disclosed position detecting device for the imaging movable optical element includes a rotating shaft fixed to a gear that rotates in conjunction with the movement of the imaging movable optical element, a cylindrical rotating body fixed to the rotating shaft, In the rotating body, a first magnetized portion provided on one end surface in the axial direction in which the rotating shaft extends, a first magnetic detection element facing the first magnetized portion, and a side surface of the rotating body, A second magnetizing portion provided along a circumferential direction of the rotating body, and a second magnetic detection element facing the second magnetizing portion, and the rotating body is disposed on the rotating shaft. The first rotating body to be fitted and the second rotating body to be fitted to the first rotating body, and the first rotating body or the second rotating body has the first rotating body. A magnetized part is provided, and the second magnetized part is provided on the second rotating body or the first rotating body, and the first The rolling element has a cylindrical first rotating portion through which the rotating shaft is inserted, and a cylindrical shape that protrudes in the axial direction from the axial end surface of the first rotating portion and through which the rotating shaft is inserted. And an area when the second rotating part is viewed from the axial direction is smaller than an area when the first rotating part is viewed from the axial direction. The body is fitted to the second rotating part of the first rotating body, and between the first rotating body and the second rotating body in the axial direction, and the first rotating body. And a magnetic shield provided on a side surface along the rotation direction of the rotating body on which the first magnetized portion is provided, of the second rotating body.

  In the disclosed position detection device for an imaging movable optical element, the second rotating portion is tapered in a protruding direction from the first rotating portion.

  In the disclosed position detecting device for the movable optical element for imaging, a concave portion is formed on the end surface on the bearing side in the axial direction of the first rotating body, and the end portion of the bearing bites into the concave portion. It is.

  In the disclosed position detection device for a movable optical element for imaging, the first rotating body is provided with the first magnetized portion, and the second rotating body is provided with the second magnetized portion. It is.

  The disclosed position detection device for an imaging movable optical element includes a bearing that rotatably supports the rotating shaft between the gear and the rotating body, and is provided between the gear and the bearing. And a restricting portion for restricting relative movement of the bearing in the axial direction.

  In the disclosed position detecting device for an imaging movable optical element, the rotation shaft supports the rotation shaft of the bearing with a length in one direction orthogonal to the axial direction between the gear and the bearing. The portion has a thick shaft portion larger than the length in the one direction, and the restricting portion is constituted by the thick shaft portion of the rotating shaft.

  In the disclosed position detecting device for a movable optical element for imaging, the rotation shaft is fitted and fixed to the gear, and the length of the portion of the rotation shaft where the gear is fitted is unidirectional. The length includes the same length as that of the restricting portion in the one direction.

  In the disclosed position detecting device for a movable optical element for imaging, the length of the restricting portion in the one direction is smaller than the length of the outer peripheral portion of the bearing in the one direction.

  In the disclosed position detecting device for the movable optical element for imaging, the restriction portion is made of a material different from that of the gear.

  The disclosed lens device includes the position detecting device for the imaging movable optical element and a focus lens or a zoom lens as the imaging movable optical element.

  The disclosed imaging device includes the lens device and an imaging element that images a subject through the imaging movable optical element.

  The present invention is particularly convenient and effective when applied to an imaging device such as a mobile phone with a camera or a digital camera, and a business lens device.

100 Position detector 1 Protective case 2 Bearing 3 Rotating shaft 3a Large diameter part (thick shaft part)
3b Small diameter portion 4 Gear 5 Rotating body 6 Rotating body 5a, 6a Magnetized portion 9, 10 Magnetic detection element

Claims (11)

A rotating shaft fixed to a gear that rotates in conjunction with the movement of the imaging movable optical element;
A cylindrical rotating body fixed to the rotating shaft;
A first magnetized portion provided on one end surface of the rotating body in the axial direction of the rotating shaft;
A first magnetic sensing element facing the first magnetized portion;
A second magnetized portion provided on a side surface of the rotating body along a circumferential direction of the rotating body;
A second magnetic sensing element facing the second magnetized portion,
The rotating body includes a first rotating body fitted to the rotating shaft and a second rotating body fitted to the first rotating body,
The first magnetized portion is provided on the first rotating body or the second rotating body,
The second magnetized portion is provided on the second rotating body or the first rotating body,
The first rotating body protrudes in the axial direction from a cylindrical first rotating portion through which the rotating shaft is inserted, and an end surface in the axial direction of the first rotating portion, and the rotating shaft is inserted through the first rotating body. A cylindrical second rotating part,
The area when the second rotating part is viewed from the axial direction is smaller than the area when the first rotating part is viewed from the axial direction,
The second rotating body is fitted to the second rotating portion of the first rotating body,
Between the first rotating body and the second rotating body in the axial direction and between the first rotating body and the second rotating body, the rotating body provided with the first magnetized portion. The position detection apparatus of the movable optical element for imaging provided with the magnetic shield provided in the side surface along the rotation direction. A position detecting device for an imaging movable optical element according to claim 1,
The position detecting device for a movable optical element for imaging, wherein the second rotating unit is tapered toward a protruding direction from the first rotating unit. A position detecting device for an imaging movable optical element according to claim 1 or 2,
In the axial direction of the first rotating body, a recess is formed on an end surface on the bearing side that rotatably supports the rotating shaft between the gear and the rotating body ,
An apparatus for detecting a position of a movable optical element for imaging, wherein an end of the bearing bites into the recess. A position detecting device for an imaging movable optical element according to any one of claims 1 to 3,
The first magnetized portion is provided on the first rotating body,
An apparatus for detecting a position of a movable optical element for imaging, wherein the second magnet is provided on the second rotating body. A position detecting device for an imaging movable optical element according to any one of claims 1 to 4,
A bearing that rotatably supports the rotating shaft between the gear and the rotating body;
An apparatus for detecting a position of a movable optical element for imaging, comprising: a restricting portion that is provided between the gear and the bearing and restricts relative movement of the rotating shaft and the bearing in the axial direction. The position detecting device for a movable optical element for imaging according to claim 5,
The rotating shaft has a thick shaft portion between the gear and the bearing in which the length in one direction orthogonal to the axial direction is larger than the length in the one direction of the portion supporting the rotating shaft of the bearing. Have
The restricting unit is a position detecting device for an imaging movable optical element configured by the thick shaft portion of the rotation shaft. The position detecting device for an imaging movable optical element according to claim 6,
The rotating shaft is fitted and fixed to the gear,
The position detecting device of the movable optical element for imaging, wherein a length in the one direction of the portion where the gear is fitted on the rotation shaft is the same as a length in the one direction of the restricting portion. The position detecting device of the movable optical element for imaging according to claim 7,
The position detecting device of the movable optical element for imaging, wherein the length of the restricting portion in the one direction is smaller than the length of the outer peripheral portion of the bearing in the one direction. A position detecting device for an imaging movable optical element according to any one of claims 5 to 8,
The restricting unit is a position detection device for an imaging movable optical element made of a material different from that of the gear. The position detecting device for an imaging movable optical element according to any one of claims 1 to 9,
A lens apparatus comprising: a focus lens or a zoom lens as the imaging movable optical element. A lens device according to claim 10;
An imaging device comprising: an imaging element that images a subject through the imaging movable optical element.

Images