WO2012120735A1

WO2012120735A1 - Blade drive device and optical device

Info

Publication number: WO2012120735A1
Application number: PCT/JP2011/077144
Authority: WO
Inventors: 保田彬; 伊藤彰浩; 山本正美
Original assignee: セイコープレシジョン株式会社
Priority date: 2011-03-08
Filing date: 2011-11-25
Publication date: 2012-09-13
Also published as: JP2012189641A

Abstract

The rotational angle range of a rotor according to the present invention is limited to an operating angle range which is smaller than a total rotational angle range of the rotor, in which the rotor can be rotated with an excited stator. When the rotor is positioned at a first end of the operating angle range, a blade is overlapped with an opening and when the rotor is positioned at a second end of the operating angle range, the blade is away from the opening. The operating angle range includes a position in the total rotational angle range, at which the torque value of the rotor becomes the maximum value in the case that the rotor rotates in the first direction when the rotational angle range of the rotor is not limited. A biasing member biases the rotor in the second direction directly or indirectly in a section at least from a halfway position to the first end in the operating angle range.

Description

Blade driving device and optical apparatus

The present invention relates to a blade driving device and an optical apparatus.

Patent Document 1 describes a blade driving device including a substrate having an opening, a blade that opens and closes the opening, and a biasing member that biases the blade so that the blade closes the opening. Since the urging member urges the blade to close the opening, the speed at which the wing advances to the opening is improved. This improves the shutter speed.

JP 2000-347241 A

However, in such a blade driving device, when the blade is maintained in the retracted position retracted from the opening, it is necessary to maintain the blade in the retracted position against the biasing force of the biasing member. For example, when the blade is maintained at the retracted position by the rotor detent torque when the actuator is not energized, it is necessary to use an actuator having a large rotor detent torque. Such an actuator is large. Further, when the blade is maintained at the retracted position using a stopper or another mechanism, the structure of the blade driving device becomes complicated, and the manufacturing cost may increase depending on the case.

Therefore, an object of the present invention is to provide a blade driving device having a simple structure and an improved shutter speed, and an optical apparatus including the blade driving device.

An object of the present invention is to provide an actuator including an urging member, a substrate having an opening, a blade that can move forward and backward with respect to the opening, a stator, and a rotor that rotates when the stator is excited and drives the blade. And when the rotor rotates in the first direction, the blade advances to the opening, and when the rotor rotates in the second direction, the blade retracts from the opening, The rotation angle range is limited to an operating angle range that is smaller than the entire rotation angle range of the rotor that can rotate when the stator is excited, and the rotor is positioned at a first end of the operating angle range. The blade overlaps the opening, and when the rotor is positioned at the second end of the operating angle range, the blade is retracted from the opening and the operating angle is The range includes a position that is the maximum value of the torque of the rotor in the entire rotation angle range when the rotor rotates in the first direction when the rotation angle range of the rotor is not limited. The urging member can be achieved by a blade driving device that urges the rotor directly or indirectly in the second direction at least in a section from the middle position of the operating angle range to the first end.

The operating angle range of the rotor includes a point where the maximum value of the torque of the rotor in the entire rotation angle range when the rotor rotates in the first direction, so that the rotor rotates in the first direction. Torque can be secured. Thereby, the speed of the blade | wing at the time of a blade | wing progressing to opening can be ensured, and the shutter speed has improved.

Further, since the urging member urges the rotor directly or indirectly in the second direction in the section from the first end of the operating angle range of the rotor to the middle position, the urging member rotates the rotor in the second direction. Assist.

The above object can also be achieved by an optical device equipped with the blade driving device.

According to the present invention, it is possible to provide a blade driving device having a simple structure and an improved shutter speed, and an optical apparatus including the blade driving device.

FIG. 1 is an exploded perspective view of the blade driving device according to the first embodiment. FIG. 2 is a perspective view of the blade driving device. FIG. 3 is a perspective view of the blade driving device. FIG. 4 is an explanatory diagram of the blade driving device in a fully opened state. FIG. 5 is an explanatory diagram of the blade driving device in a state between the fully open state and the fully closed state. FIG. 6 is an explanatory diagram of the blade driving device in the fully closed state. 7A to 7D are explanatory diagrams of the rotation of the rotor. FIG. 8 is a graph showing torque fluctuations according to the rotation angle of the rotor in the electromagnetic actuator of the first embodiment. FIG. 9 is a graph showing torque fluctuations according to the rotation angle of the rotor in a conventional electromagnetic actuator. FIG. 10 shows an example of changing the operating angle range. FIG. 11 is an explanatory diagram of the blade driving device of the second embodiment. FIG. 12 is a graph showing torque fluctuations according to the rotation angle of the rotor in the electromagnetic actuator of the second embodiment. FIG. 13 is an explanatory diagram of a blade driving device according to the third embodiment. FIG. 14 is an explanatory diagram of the blade driving device of the third embodiment. FIG. 15 is an explanatory diagram of the blade driving device of the third embodiment. FIG. 16 is an explanatory diagram of a blade driving device according to the fourth embodiment. 17A and 17B are explanatory diagrams of the blade driving device of the fourth embodiment.

A plurality of embodiments will be described below.

FIG. 1 is an exploded perspective view of the blade driving device 1 according to the first embodiment, and FIGS. 2 and 3 are perspective views of the blade driving device 1. The blade driving device 1 is a blade driving device employed in an optical device such as a camera. The blade driving device 1 is a so-called focal plane shutter. The blade driving device 1 includes a substrate 10, a plurality of blades 20,

arms

30a and 30b, urging

members

40a and 40b, an electromagnetic actuator A, and driving

members

90a and 90b. The substrate 10 is provided with an opening OP. The light on the subject side passes through the opening OP and is incident on an image sensor such as a CCD or CMOS sensor provided on the camera side. Thereby, an image is formed by the image sensor. The substrate 10 has a first surface 11 and a second surface 12. The electromagnetic actuator A is disposed on the first surface 11 side, and the blade 20 is disposed on the second surface 12 side. The blades 20 constitute a so-called rear curtain. The blade driving device 1 is a focal plane shutter for a camera having a function called an electronic front curtain that realizes the function of the front curtain by controlling the exposure timing of the image sensor. In this embodiment, as described above, the focal plane shutter having only the rear curtain will be described. However, the present invention is not limited to this embodiment, and is applied to the focal plane shutter having the front curtain and the rear curtain. Also good. In that case, the front curtain may be operated by the same mechanism as the rear curtain.

The

arms

30a and 30b can swing around the

support shafts

13a and 13b formed on the second surface 12 side. In addition, the rotation member 50b shown in FIG. 1 is fitted to the support shaft 13b, and the fitting hole 35b of the arm 30b is fitted to the rotation member 50b. Although not shown, a similar rotating member is fitted to the support shaft 13a, and the fitting hole 35a of the arm 30a is fitted to this rotating member. The

arms

30a and 30b are connected to the plurality of blades 20, respectively. The

arms

30a and 30b function as parallel links. The

urging members

40a and 40b are torsion springs. The

urging members

40a and 40b will be described later.

The electromagnetic actuator A includes a rotor 60 rotatably supported on the substrate 10, a stator 70 that rotates the rotor 60 when a magnetic force acts between the rotor 60, a coil 85 that excites the stator 70, and a coil 85. A coil bobbin 82 that is wound and assembled to the stator 70 is included.

Magnetic pole portions

72a and 72b are formed at both ends of the stator 70 facing the rotor 60, respectively. When the coil 85 is energized, the

magnetic pole portions

72a and 72b are excited to have different polarities. The rotor 60 is magnetized with different polarities in the circumferential direction. The rotor 60 rotates within a predetermined range by a magnetic attractive force and a repulsive force acting between the

magnetic pole portions

72 a and 72 b and the rotor 60.

The drive member 90 a has a fitting hole 94 a that fits into the end of the rotor 60, and rotates together with the rotor 60. The drive member 90a is provided with a gear portion 95a. The driving member 90b is rotatably supported on the first surface 11 side of the substrate 10. The drive member 90b is formed with a shaft hole 94b slidably fitted to a shaft portion formed on the first surface 11 of the substrate 10. The drive member 90b has a gear portion 95b that meshes with the gear portion 95a of the drive member 90a. A drive pin 96b is formed on the drive member 90b. The drive pin 96b passes through the escape hole 16 formed in the substrate 10 and is fitted into the fitting hole 36a of the arm 30a. Accordingly, when the rotor 60 rotates, the

drive members

90a and 90b rotate and the arm 30a swings. As the arm 30a swings, the arm 30b swings, whereby the blade 20 moves forward and backward with respect to the opening OP. The blade 20 retracts from the opening OP to open the opening OP, and shields the opening OP to fully close the opening OP.

FIG. 4 shows a fully open state, FIG. 5 shows a state halfway between the fully open state and the fully closed state, and FIG. 6 shows a fully closed state. 4 to 6 are views of the blade driving device 1 as viewed from the second surface 12 side of the substrate 10.

As shown in FIG. 4, the urging

members

40a and 40b are wound around the

support shafts

13a and 13b, respectively. In the fully open state, the one end 41a of the urging member 40a is in a free state without being in contact with other members. The other end 42a of the urging member 40a is engaged with the engagement hole 32a of the arm 30a. That is, the other end 42a of the urging member 40a is connected to the arm 30a. Similarly, in the urging member 40b, the one end 41b is not in contact with another member, and the other end 42b is engaged with the engagement hole 32b of the arm 30b. In addition, the board | substrate 10 is formed with the escape hole 17 for escaping the other end part 42b of the urging | biasing member 40b in circular arc shape.

When the rotor 60 rotates in a predetermined direction, as shown in FIG. 5, the drive pin 96b moves and the

arms

30a and 30b and the blades 20 advance toward the opening OP. While the blade 20 moves from the position retracted from the opening OP to the position closing the opening OP, each of the one end 41a of the biasing member 40a and the one end 41b of the biasing member 40b is on the first surface 11 side of the substrate 10. It abuts on the

pins

14a and 14b formed on the surface.

Further, when the rotor 60 rotates, as shown in FIG. 6, the drive pin 96b further moves and the blade 20 completely closes the opening OP. As shown in FIG. 6, the angle between the one end 41a and the other end 42a of the urging member 40a is smaller than that in FIG. The same applies to the urging member 40b. Therefore, the urging forces of the urging

members

40a and 40b increase from the state shown in FIG. 5 to the state shown in FIG. Therefore, the urging

members

40a and 40b urge the blades 20 to retreat from the openings OP, in other words, the blades 20 open the openings OP. The rotor 60 drives the blades 20 against the urging force of the urging

members

40a and 40b to close the opening OP.

Next, the rotation of the rotor 60 will be described. 7A to 7D are explanatory diagrams of the rotation of the rotor 60. FIG. 7A-7D show the rotor 60 during the transition from the fully open state to the fully closed state. FIG. 7A shows the stop position of the rotor 60 in the fully opened state. In this state, the rotor 60 is stopped while the drive pin 96b is in contact with one end of the escape hole 16. Therefore, the counterclockwise rotation of the rotor 60 is restricted. In this state, since the coil 85 is not energized, the

magnetic pole portions

72a and 72b have no polarity. Therefore, the rotor 60 is stopped by the detent torque.

In this state, when the coil 85 is energized in a predetermined direction, as shown in FIG. 7B, an S pole is generated in the magnetic pole portion 72a and an N pole is generated in the magnetic pole portion 72b. The magnetic pole portion 72a excited to the S pole and the magnetic pole center of the S pole of the rotor 60 generate a repulsive force, and the magnetic pole portion 72b excited to the N pole and the magnetic pole center of the N pole of the rotor 60 generate a repulsive force. Arise. Due to this repulsive force, the rotor 60 starts to rotate clockwise.

FIG. 7C shows a state when the rotor 60 is rotated by a predetermined angle from the state of FIG. 7B. In this state, the magnetic pole center of the N pole of the rotor 60 generates an attractive force with the magnetic pole part 72a and generates a repulsive force with the magnetic pole part 72b. Further, the magnetic pole center of the S pole of the rotor 60 generates an attractive force with the magnetic pole part 72b and generates a repulsive force with the magnetic pole part 72a.

FIG. 7D shows a state where the rotor 60 is further rotated in the clockwise direction. In this state, the drive pin 96b contacts the other end of the escape hole 16, and the rotation of the rotor 60 is stopped. In this state, the opening OP is fully closed. In addition, after a predetermined period of time has elapsed in this state, energization to the coil 85 is stopped, and the rotor 60 is maintained at this position by detent torque.

When the blade 20 is retracted from the opening OP, the rotor 60 rotates counterclockwise by exciting the

magnetic pole portions

72a and 72b to the N pole and the S pole, respectively, from the state shown in FIG. 7D. . As a result, the blade 20 is retracted from the opening OP.

FIG. 8 is a graph showing a variation in torque according to the rotation angle of the rotor 60 of the electromagnetic actuator A of the first embodiment. In FIG. 8, the horizontal axis represents the rotation angle of the rotor, and the vertical axis represents the torque. The center of the horizontal axis is a rotation angle of 90 °, and the position of the rotor 60 at 90 ° corresponds to the position of the rotor 60 shown in FIG. 7A.

Torque T1 indicates the torque when the rotor 60 rotates in the first direction when the stator 70 is excited. Here, when the rotor 60 rotates in the first direction, the blade 20 advances toward the opening OP. The rotation of the rotor 60 in the first direction means that the rotor 60 shown in FIGS. 7A to 7D rotates in the clockwise direction. Torque T2 indicates the torque when the rotor 60 rotates in the second direction when the stator 70 is excited. Here, when the rotor 60 rotates in the second direction, the blade 20 retracts from the opening OP. The fact that the rotor 60 rotates in the second direction means that the rotor 60 shown in FIGS. 7A to 7D rotates counterclockwise. When the rotor 60 rotates counterclockwise, the rotor 60 rotates from the position shown in FIG. 7D.

The operating angle range DR is an actual rotation range of the rotor 60. The rotation range of the rotor 60 is regulated by the drive pin 96b coming into contact with the escape hole 16 as described above. Therefore, the torques T1 and T2 shown in FIG. 8 indicate torques in the entire rotation angle range of the rotor 60 when there is no such restriction. That is, the torques T1 and T2 are torques in the entire rotation angle range of the rotor 60 that can be rotated by exciting the stator 70 when the rotation range of the rotor 60 is not limited. The detent torque DT indicates a torque necessary for rotating the rotor 60 in a state where the energization to the coil 85 is interrupted. In FIG. 8, the point where the detent torque DT becomes zero is set as 90 °. The operating angle range DR includes a point of the maximum value M of the torque T1. Further, the center position PC of the operating angle range DR is located between the first end P1 and 90 °.

The first end P1 of the operating angle range DR is set around 135 °, and the second end P2 of the operating angle range DR is set around 90 °. Therefore, the operating angle range DR is set to about 45 °. When the rotor 60 rotates in the first direction, the rotor 60 rotates from the second end P2 toward the first end P1. When the rotor 60 rotates in the second direction, the rotor 60 rotates from the first end P1 toward the second end P2. The absolute value of the detent torque DT at the first end P1 is larger than the absolute value of the detent torque DT at the second end P2.

As described above, the blade driving device 1 includes the urging

members

40a and 40b. The urging

members

40a and 40b urge the

arms

30a and 30b from the midway position of the operating angle range DR to the first end P1. The urging

members

40a and 40b urge the

arms

30a and 30b so that the rotor 60 rotates in the second direction. That is, the urging

members

40a and 40b indirectly urge the rotor 60 so that the rotor 60 rotates in the second direction. The spring torque ST indicates the torque applied to the rotor 60 by the urging

members

40a and 40b. The spring torque ST increases as the rotor 60 approaches the first end P1. The torque FT1 is a torque when the rotor 60 rotates in the first direction when the spring torque ST is applied. That is, the torque FT1 is an actual torque when the rotor 60 rotates in the first direction. The torque FT1 is lower than the torque T1 in the section from the midway position of the operating angle range DR to the first end P1. This is because the spring torque ST of the urging

members

40a and 40b acts as a minus with respect to the torque T1.

The torque FT2 is a torque when the rotor 60 rotates in the second direction when the spring torque ST is applied. That is, the torque FT2 is an actual torque when the rotor 60 rotates in the second direction. As shown in FIG. 8, the torque FT2 is a section from the first end P1 to the midway position of the operating angle range DR, and the torque in the second direction is greater than the torque T2. This is because the spring torque ST of the urging

members

40a and 40b acts as a plus with respect to the torque T2. The detent torque FDT indicates the detent torque when the spring torque ST is applied. That is, the detent torque FDT is an actual detent torque of the rotor 60.

FIG. 9 is a graph showing the variation of torque according to the rotation angle of the rotor in the conventional electromagnetic actuator. The operating angle range DRx of the rotor of the conventional electromagnetic actuator is set so that 90 ° of the point where the detent torque DT becomes zero is approximately the center. The reason is that the torque T12x when the rotor 60 starts to rotate in the first direction from the second end P2x or the torque T21x when it starts to rotate in the second direction from the first end P1x is too weak, and the blade 20 This is to make the torque T12x and the torque T21x substantially equal so that the forward / backward movement cannot be performed. When the operating angle range DRx is set in this way, the operating angle range DRx does not include the point of the maximum value M of the torque T1, and the torque when the rotor 60 starts to rotate in the first direction, that is, the first The torque T12x of the rotor 60 at the two ends P2x is small. For this reason, the speed at which the blades 20 advance to the opening OP decreases, and the shutter speed may decrease.

On the other hand, in the blade drive device 1 of the present embodiment, the operating angle range DR includes a point of the maximum value M of the torque T1. Further, the center position PC of the operating angle range DR is located between the first end P1 and 90 °. Thereby, the torque T12 at the second end P2 becomes larger than the torque T12x at the second end P2x. Thereby, the rotor 60 rotates with a strong torque from the beginning when the rotor 60 starts rotating in the first direction. For this reason, the speed at which the blade 20 advances to the opening OP is also improved. Thus, the shutter speed is improved with a simple structure.

However, when the operating angle range DR is set to such a range, the torque when the rotor 60 starts to rotate in the second direction, that is, the value of the torque T21 at the first end P1 is the first end P1x. Lower than the value of the torque T21x. For this reason, there is a possibility that the torque when the rotor 60 starts to rotate in the second direction from the second end P2 is too weak and the blades 20 cannot be reliably retracted from the opening OP.

Therefore, in the blade driving device 1 according to the first embodiment, by providing the urging

members

40a and 40b for urging the

arms

30a and 30b so as to retract the blade 20 with respect to the opening OP, respectively, Evacuation is secured.

Here, some conventional blade driving devices include an urging member that urges the blade in the direction in which the blade proceeds to the opening in order to improve the shutter speed. When such an urging member is provided, it is necessary to keep the blade in the retracted position against the urging force of the urging member. For example, when the blade is maintained at the retracted position by the rotor detent torque when the actuator is not energized, it is necessary to use an actuator having a large rotor detent torque. Such an actuator is large. Further, when the blade is maintained at the retracted position using a stopper or another mechanism, the structure of the blade driving device becomes complicated, and the manufacturing cost may increase depending on the case.

However, in this embodiment, the urging

members

40a and 40b urge the

arms

30a and 30b so that the blades 20 are retracted from the opening OP. Further, when the blade 20 is in the retracted position, the urging force of the urging

members

40 a and 40 b does not act on the blade 20. For this reason, even if the detent torque of the rotor 60 when the blade 20 is in the retracted position is weak, the blade 20 can be maintained in the retracted position.

Further, the biasing

members

40a and 40b are not biased over the entire operating angle range DR. For this reason, the torque when the rotor 60 starts to rotate in the first direction from the second end P2 is not affected. Therefore, a decrease in shutter speed is suppressed.

Further, the urging

members

40a and 40b urge the blades 20 to open the openings OP when the blades 20 close the openings OP. For this reason, the traveling speed of the blade 20 is reduced immediately before the blade 20 completely closes the opening OP by the biasing force of the biasing

members

40a and 40b. Therefore, the urging

members

40a and 40b also serve as a speed reduction member. This prevents the drive pin 96b or the like from bouncing against the escape hole 16 in a bouncing manner. Thereby, re-exposure is prevented.

The urging

members

40a and 40b are arranged so that the blade 20 rotates in the second direction in a section where the rotor 60 does not rotate in the second direction from the first end P1 when at least the urging

members

40a and 40b are not provided. The

arms

30a and 30b are biased. According to FIG. 8, the torque T2 in the section where the spring torque ST of the urging

members

40a and 40b acts shows a negative value. For this reason, if no resistance acts on the rotation of the rotor 60, the rotor 60 can rotate in the second direction. However, as described above, the driving member 90a is fixed to the rotor 60, and the driving member 90a is connected to the blades 20 via a plurality of members, so that there are not a few mechanical loads due to friction or the like. . For this reason, even if the torque T2 shows a negative value at the second end P2, the mechanical load cannot be overcome and the rotor 60 may not rotate in the second direction. In such a section, the urging

members

40a and 40b assist the blade 20 to retreat from the opening OP.

FIG. 10 shows an example of changing the operating angle range. The operating angle range DR ′ is set such that the first end P1 ′ is about 122.5 ° and the second end P2 ′ is about 80 °. The operating angle range DR ′ includes a point of the maximum value M of the torque T1. Further, the center position PC ′ of the operating angle range DR ′ is located between the first end P1 ′ and 90 °. Even in such an operating angle range DR ′, the shutter speed is improved. In FIG. 10, the spring torque ST is omitted.

Only one of the urging

members

40a and 40b may be provided. Further, such an urging member may urge any member that interlocks with the rotor 60 by rotation. For example, what is necessary is just to energize at least 1 of the blade | wing 20 linked with the rotor 60, and drive

member

90a, 90b. This is because the biasing member indirectly biases the rotor 60 in the second direction. Further, the biasing member may bias the rotor 60 directly in the second direction.

FIG. 11 is an explanatory diagram of the blade driving device 1a according to the second embodiment. In addition, about the structure similar to Example 1, the description is abbreviate | omitted by attaching | subjecting the same code | symbol. The one

end portions

41a and 41b of the urging members 40a 'and 40b' are always in contact with the

pins

14a and 14b, respectively. That is, even when the blade 20 is in the retracted position, the biasing members 40a ′ and 40b ′ bias the

arms

30a and 30b so that the blade 20 retracts from the opening OP. The electromagnetic actuator employed in the blade driving device 1a according to the second embodiment is the same as the electromagnetic actuator employed in the blade driving device 1 according to the first embodiment.

FIG. 12 is a graph showing torque fluctuations according to the rotation angle of the rotor 60 in the electromagnetic actuator of the second embodiment. FIG. 12 corresponds to FIG. The urging members 40a ′ and 40b ′ urge the

arms

30a and 30b over the entire operating angle range DR. The spring torque STa indicates the torque applied to the rotor 60 by the biasing members 40a ′ and 40b ′. The spring torque STa increases as the rotor 60 approaches the first end P1. The torque FT1a is a torque when the rotor 60 rotates in the first direction when the spring torque STa is applied. The torque FT2a is a torque when the rotor 60 rotates in the second direction when the spring torque STa is applied.

Even at the second end P2, the spring torque ST acts on the rotor 60, but the value of the spring torque ST at the second end P2 is relatively small. Therefore, the speed at which the blade 20 advances to the opening OP is also maintained, and the shutter speed is improved with a simple structure.

Further, even when the rotor 60 is positioned at the second end P2, the urging members 40a ′ and 40b ′ are urged in the direction in which the blades 20 are retracted from the opening OP. Therefore, even when the coil 85 is not energized, the blade 20 can be stably maintained at the retracted position.

FIGS. 13 to 15 are explanatory views of the blade driving device 1A of the third embodiment when shifting from the fully open state to the fully closed state. In addition, about the structure similar to Example 1, the description is abbreviate | omitted by attaching | subjecting the same code | symbol. FIG. 13 shows a fully open state, FIG. 14 shows a state between the fully open state and the fully closed state, and FIG. 15 shows a fully closed state. In FIGS. 13 to 15, the shape of the substrate 10A is omitted. The rotation range of the rotor 60 of the electromagnetic actuator AA is the same as the rotation range shown in FIG.

As shown in FIG. 13, a biasing member 40A is fixed to the first surface 11A side of the substrate 10A. The urging member 40A is wound around a pin 14A formed on the first surface 11A side. That is, the pin 14A is fixed to the substrate 10A. The urging member 40 </ b> A has one end 41 </ b> A that extends toward the rotor 60. The one end 41A extends between the substrate 10A and the stator 70. The drive member 90A is provided with a protrusion 98a. In the state shown in FIG. 13, the protrusion 98a of the drive member 90A is not in contact with the one end 41A of the urging member 40A.

As shown in FIG. 14, when the rotor 60 rotates, the drive member 90A rotates and the protrusion 98a contacts the one end 41A of the biasing member 40A. When the rotor 60 further rotates, the protrusion 98a pushes the one end 41A of the urging member 40A to deform the urging member 40A. Thereby, a biasing force in the second direction acts on the rotor 60 via the drive member 90A. By adopting such an urging member 40A, the shutter speed can be improved with a simple structure. Further, retraction from the opening OP of the blade 20 is ensured.

Such a protrusion that can come into contact with the one end 41A of the urging member 40A may be provided on the drive member 90b side, or may be provided directly on the rotor 60. Further, such a protrusion may be integrally formed with the rotor 60. Further, the urging member 40A may be fixed to the rotor 60 so as to rotate together with the rotor 60, and a protrusion that can contact the urging member 40A may be provided on the substrate 10A.

16 to 17B are explanatory diagrams of the blade driving device 1B of the fourth embodiment. In addition, about the structure similar to Example 1, the description is abbreviate | omitted by attaching | subjecting the same code | symbol. FIG. 16 shows a fully opened state, FIG. 17A shows a state between the fully opened state and the fully closed state, and FIG. 17B shows a fully closed state.

The substrate 10B has a substantially circular shape. The substrate 10B has a substantially circular opening OPB. A drive member 90B is fixed to the lower end of the rotor 60B. When the driving member 90B rotates together with the rotor 60B, the blade 20B swings to open and close the opening OPB. The board 10B is formed with pins 14B that contact the stator 70B of the electromagnetic actuator AB and position the stator 70B. A biasing member 40B is wound around the upper end of the rotor 60B of the electromagnetic actuator AB and fixed to the rotor 60B. The urging member 40B has one end portion 41B extending outward in the radial direction of the urging member 40B and the other end portion 42B shorter than the one end portion 41B.

In the fourth embodiment, unlike the first to third embodiments, rotating the rotor 60B shown in FIGS. 16 to 17B in the clockwise direction means rotating in the second direction, and the rotor 60B rotates in the counterclockwise direction. It means to rotate in the first direction.

When the rotor 60B starts to rotate counterclockwise from the state shown in FIG. 16, the one end 41B of the urging member 40B comes into contact with the pin 14B as shown in FIG. 17A. Further, when the rotor 60B rotates counterclockwise, the biasing member 40B is deformed so that the angle between the one end 41B and the other end 42B is reduced as shown in FIG. . Thereby, the urging member 40B indirectly urges the blade 20B so that the blade 20B opens the opening OPB. Even with such a configuration, the shutter speed can be improved with a simple structure. Further, retraction from the opening OPB of the blade 20B is ensured.

The urging member 40B may be fixed to the driving member 90B and rotated together with the driving member 90B. Further, the urging member 40B may be fixed to the substrate 10B, and the driving member 90B may abut against the urging member 40B.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

Claims

A biasing member;
A substrate having an opening;
Blades that can be moved forward and backward with respect to the opening;
An actuator including a stator and a rotor that rotates when the stator is excited and drives the blades;
When the rotor rotates in the first direction, the blades advance to the opening,
When the rotor rotates in the second direction, the blades retract from the opening,
The rotation angle range of the rotor is limited to an operating angle range that is smaller than the entire rotation angle range of the rotor that can rotate when the stator is excited,
When the rotor is located at the first end of the operating angle range, the blades overlap the opening;
When the rotor is located at the second end of the operating angle range, the blade is retracted from the opening;
The operating angle range is a position that is the maximum value of the torque of the rotor in the entire rotation angle range when the rotor rotates in the first direction when the rotation angle range of the rotor is not limited. Contains
The urging member is a blade driving device that urges the rotor directly or indirectly in the second direction at least in a section from the middle position of the operating angle range to the first end.
The blade drive device according to claim 1, wherein the rotor has a larger detent torque when the rotor is positioned at the first end than when the rotor is positioned at the second end.
The blade driving device according to claim 1 or 2, wherein the biasing member biases the rotor directly or indirectly in the second direction in a section from the first end to the second end.
The blade driving device according to claim 1 or 2, wherein the urging force of the urging member increases as the rotor approaches the first end.
The biasing member biases the rotor directly or indirectly in the second direction in a section where the rotor does not rotate in the second direction from the first end when the biasing member is not provided. The blade driving device according to claim 1 or 2.
The blade driving device according to claim 1 or 2, wherein the biasing member also serves as a speed reducing member that reduces the traveling speed of the blade immediately before the blade completely closes the opening.
The blade driving device according to claim 1 or 2, wherein the biasing member is a torsion spring.
An optical apparatus comprising the blade driving device according to claim 1.