JP2008111959A - Device for adjusting light quantity, and optical imaging equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accelerate the time required, starting from light shielding, until completing it without increasing an angle of turning from the start of a light-shielding blade drive shaft, until the stop thereof, while achieving miniaturization. <P>SOLUTION: In the device for adjusting light quantity, round holes 3a and 4a of light shielding blades 3 and 4 are respectively rotatably fit to the light-shielding blade driving shaft 2a of a rotor magnet 2 fit to the supporting shaft 1a of a bottom board 1, and long grooves 3b and 4b, bent at a plurality of spots of the light-shielding blades 3 and 4 are respectively engaged with the engaging shaft 1b of the bottom board 1. By the rotation of the rotor magnet 2, the light-shielding blades 3 and 4 turn with abutting positions as turning fulcrums, while the long grooves 3b and 4b shift the abutting positions on the engaging shaft 1b. The angles of turning of the light-shielding blades 3 and 4 are controlled by the bent state of the bent spots and light shielding, when starting the drive of the light-shielding blades 3 and 4 is accelerated, then the angle of turning from finishing light-shielding, until stopping it is made large to prevent re-exposure due to bound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light amount adjusting device such as a shutter device used in an optical imaging device such as a digital still camera.

  6A and 6B are plan views showing a conventional light amount adjusting device, in which FIG. 6A is a diagram illustrating a light shielding blade open state, FIGS. 6B and 7C are a light shielding transient state, and FIG.

  6 and 7 includes a light shielding blade group in which a right light shielding blade 14 that performs light shielding operation in a clockwise turn and a left light shielding blade 13 that performs light shielding operation in a counterclockwise turn form a pair. Yes.

  Each of the right light shielding blade 14 and the left light shielding blade 13 is rotatable about the support shafts 11a and 11b, and the light shielding blade driving shaft 12a is engaged with the long groove portion 14b formed in the right light shielding blade 14. .

  Further, the light shielding blade drive shaft 12 a rotates about the support shaft 11 a by the rotation of the rotor magnet 12. As a result, when the right light shielding blade 14 turns in the direction to close the opening hole 11c formed in the base plate 11, the right light shielding blade 13 turns clockwise about the support shaft 11a, and the left light shielding blade 13 counteracts about the support shaft 11b. It turns clockwise, the left and right light shielding blades 13 and 14 turn from the open state to the light shielding state, and the opening hole 11c formed in the base plate 11 is shielded from light.

  Further, when the light shielding blade drive shaft 12a rotates counterclockwise around the support shaft 11a, the left and right light shielding blades 13 and 14 rotate from the light shielding state to the open state, and the opening hole 11c is opened (Patent Document 1). .

  On the other hand, contrary to the above-described configuration of the conventional example, the first engagement hole with which the blade drive shaft that opens and closes the light-shielding blade engages is a round hole, and the second engagement with the restriction member fixed to the shutter base plate. A light quantity adjusting device having a long groove as an engagement hole is proposed (Patent Document 2).

  In the light amount adjusting device described in Patent Document 2, when the round hole of the light shielding blade moves with the movement of the blade drive shaft that engages with the round hole, the long groove that engages the regulating member is The contact position of will shift. In accordance with this deviation, the blade acts to swing.

By adopting such a configuration, the rotation center of the light shielding blade can be arranged relatively freely, and the device can be made smaller than the conventional light amount adjusting device described in Patent Document 1.
JP 2002-182266 A JP 2005-77765 A

  In recent years, products such as a digital still camera and a digital video camera that require a light amount adjusting device such as a shutter device are required to be small and have high image quality. Inevitably, there is a demand for a light amount adjusting device that is small and operates at high speed.

  In the conventional light amount adjusting device shown in FIGS. 6 and 7 and the device described in Patent Document 2, in order to speed up the time from the start of light shielding to the completion of light shielding, the light shielding blade driving force may be increased. There are limitations due to space constraints.

  Further, if the light shielding blade is made small in order to reduce the moment of inertia of the light shielding blade with respect to the turning direction of the light shielding blade drive shaft, the opening hole cannot be completely shielded from light. Further, if the thickness of the light shielding blade is reduced to reduce the moment of inertia, the end surfaces of the long grooves 13b and 14b of the light shielding blades 13 and 14 may be crushed by the light shielding blade drive shaft 12a. is there.

  Furthermore, a method has also been proposed in which the turning angle from the start of turning of the light shielding blade to the start of light shielding is increased to start the light shielding when the turning speed is increased. There is a limit due to space constraints, including the space to absorb the bounce of the light shielding blades caused by collision.

  Further, in the light amount adjusting device of Patent Document 2, the rotation center of the blade can be arranged relatively freely, and the device can be made smaller than the conventional example shown in FIGS. 6 and 7, but the turning angle and turning speed of the light shielding blade can be reduced. The relationship is the same as that of the conventional example shown in FIGS. 6 and 7, and has the same problem with respect to the operating speed and the bounce of the light shielding blade after completion of the light shielding.

  Therefore, an object of the present invention is to reduce the light amount adjusting device, and without increasing the turning angle from the start to the stop of the light shielding blade drive shaft, and a light amount adjusting device having a fast required time from the start of light shielding to the completion of light shielding. An object of the present invention is to provide an optical imaging device provided with a light amount adjusting device.

  According to a first aspect of the present invention, there is provided a light amount adjusting device having a plurality of light shielding blades for controlling incident light and an opening for allowing the incident light to pass through. A ground plate movably disposed; a drive source attached to the ground plate for moving the light shielding blade; blade driving means for moving the light shielding blade along a predetermined locus by a driving force of the drive source; and the ground plate And a regulating member that regulates the movement of the light shielding blade, and the light shielding blade shifts the contact position with the regulating member in response to the movement by the blade driving means and the regulation of the regulating member. A light quantity adjusting device that turns with the abutment position as a turning fulcrum, wherein the blade driving means rotatably supports the at least one light shielding blade, and the light shielding blade moves the blade driving means. According to before Characterized in that the contact between the regulating member and a longitudinal groove provided with a plurality of bent portions for regulating the turning direction of the light shielding blade.

  Furthermore, it is better that the plurality of bent portions have the inflection points at least before the shielding blade starts to shield the opening of the main plate and after the shielding.

  Further, the inflection point is that the rotation angle of the blade driving means and the movement ratio of the light shielding blade change from small to large before the light shielding blade starts to shield the opening of the ground plane, and the opening After shielding, it is desirable to form so as to change from large to small.

  Also, the shape of both ends of the bent long groove of the light shielding blade is substantially the same as the shape of the portion contacting the both ends of the long groove of the regulating member, and the both ends are contacted to open the light shielding blade on the open side and the light shielding side stopper. To be configured. This makes it possible to use a light shielding blade that is thinner and lighter than the conventional light shielding blade.

  According to a fourth aspect of the present invention, there is provided an optical imaging device comprising: a light amount adjusting device having any one of the above-described configurations; and an imaging unit that forms an image of subject light passing through the light amount adjusting device. It is characterized by having.

  According to the present invention, for example, a rotary drive blade driving shaft provided in a rotor magnet as a driving source is rotatably engaged with a round hole formed on one end side of the light shielding blade, and the blade driving shaft is rotated. When the light shielding blade moves, the long groove provided in the light shielding blade acts as a turning fulcrum of the blade by abutting with the regulating member, and depending on the contact position with the bent portion of the long groove, the light shielding Since the blade swivel angle can be increased or decreased, the time from the start of blade drive means to the completion of light shielding can be shortened while downsizing the device, and the re-exposure by bounce by increasing the swivel angle from the completion of light shielding to the turning stop. Can be prevented.

  Specifically, it is possible to shorten the time from the start to the completion of the light shielding by reducing the turning angle of the light shielding blade drive shaft from the start of the light shielding to the completion of the light shielding by the bent long groove. Further, by increasing the turning angle of the light-shielding blade drive shaft from the completion of light shielding until the turning is stopped by the bent long groove, even if the light-shielding blade bounces after contacting the end of the long groove, it is configured not to be re-exposed. .

  Furthermore, the configuration is such that both ends of the bent long groove and the regulating member fitted to the long groove have substantially the same shape and the contact surfaces of both are widened so that the long groove is not crushed when the light shielding blade is stopped on the open side and the light shielding side. Yes. This makes it possible to use thin light shielding blades.

  If the product specifications are not hindered, the long groove may be linear.

The present invention will be described below with reference to embodiments shown in the drawings.
First Embodiment FIGS. 1 to 4 show a first embodiment of the present invention.

  FIG. 1 is a plan view of a light quantity adjusting device, where (a) is a light shielding blade open state, (b) and (c) are light shielding transient states, FIG. 2 is a plan view showing a light shielding completion stop state, and FIG. FIG. 4 is a cross-sectional view of the light quantity adjusting device shown in FIGS. 1 and 2.

  A base plate 1 that is a substrate member in which an opening 1c is formed includes a support shaft 1a that rotatably supports a rotor magnet (cylindrical permanent magnet) 2, and a plurality of light shielding blades (two in this embodiment). An engagement shaft 1b that is a restricting member that engages with bent (having a plurality of inflection points), which will be described later, formed on the first light shielding blade 3 and the second light shielding blade 4, respectively. -The stator yoke 5 and the concave portion 1e for accommodating and attaching the electromagnetic coil 6 inserted and attached to the stator yoke 5 are formed on the same side.

  The rotor magnet 2 is formed with a round hole 2b that is rotatably fitted to the support shaft 1a, and as shown in FIG. 4, the light shielding blade is driven at a radially outward position shifted from the round hole 2b. The shaft 2a is formed so as to protrude to one side of the base plate 1, and further, magnetic poles (N, S) magnetized in two poles are formed on the outer peripheral surface.

  An electromagnetic coil 6 formed by winding a winding coil around a bobbin is inserted into a horseshoe-shaped stator yoke 5 made of a soft magnetic material, and is inserted into the recess 1e of the base plate 1 to be positioned and attached. The stator yoke 5 constitutes a magnetic circuit by magnetic pole portions 5a and 5b arranged to face the outer peripheral curved surface of the rotor magnet 2 of a cylindrical permanent magnet. In FIG. 4, the rotor magnet 2 is held by this magnetic circuit and does not move toward the light shielding blades 3 and 4 (in the axial direction of the support shaft 1).

  As shown in FIG. 1 (a), the first light shielding blade 3 has a round hole 3a formed at the rear end thereof fitted into the light shielding blade driving shaft 2a of the rotor magnet 2, and is located at the middle portion of the entire blade in the length direction. A bent long groove 3b extending in the width direction of the entire blade is formed closer to the round hole 3a than the formed constricted portion. An engagement shaft 1b provided at a position not overlapping with the rotor magnet 2, the stator yoke 5 and the electromagnetic coil 6 of the base plate 1 is fitted in the long groove 3b. Further, the rotor magnet 2 and the stator yoke 5 are arranged at a position overlapping the first light shielding blade 3, and the electromagnetic coil 6 is located outside the operating region of the first light shielding blade 3.

  Further, the second light shielding blade 4 has a round hole 4a formed in the rear end portion thereof fitted into the light shielding blade drive shaft 2a of the rotor magnet 2 and is more constricted than a constricted portion formed in an intermediate portion in the length direction of the entire blade. A bent long groove 4b extending long in the width direction of the entire blade is formed near the round hole 4a. The long shaft 4b is engaged with the engaging shaft 1b of the base plate 1.

  That is, the round hole 3a of the first light shielding blade 3 and the round hole 4a of the second light shielding blade 4 are both fitted to the same light shielding blade drive shaft 2a, and the elongated hole 3b of the first light shielding blade 3 and the second light shielding blade 4 Both the long holes 4b are fitted to the same engagement shaft 1b.

  The first light-shielding blade 3 and the second light-shielding blade 4 are rotated between the fully open state in FIG. 1A and the fully closed state in FIG. 2 by turning the light-shielding blade drive shaft 2a as the rotor magnet 2 turns. b) It is attached so as to move through the state shown in (c). That is, the long groove 3b of the first light-shielding blade 3 and the long groove 4b of the second light-shielding blade 4 intersect in a state of being fitted to the engagement shaft 1b, and in FIG. 1, the magnet rotor 2 is shown in FIG. When rotating in the clockwise direction from the fully open state, the first light-shielding blade 3 starts to turn counterclockwise while the engagement position that forms the turning fulcrum where the long groove 3b engages with the engagement shaft 1b is shifted.

  At this time, since the distance between the light shielding blade drive shaft 2a and the engagement shaft 1b changes, the engagement position of the long groove 3b with respect to the engagement shaft 1b is changed to absorb the change. When the inner peripheral edge of the long groove 3b that is in contact with the shaft 1b is not a straight line but is bent (having an inflection point), a convex inner peripheral edge is formed inside the long groove 3b, and a concave inner peripheral edge is connected to the outside. The curved surface comes into contact with the engagement shaft 1b. When the magnet rotor 2 is turned, if the inner periphery of the long groove 3b is a straight line, a concave portion on the inner periphery (the inner periphery far from the round hole 3a) of the long groove 3b contacts the engagement shaft 1b. In addition, the first light-shielding blade 3 further turns counterclockwise, and the magnet roller 2 further turns. Moreover, when the convex part in the inner peripheral edge (the inner peripheral edge far from the round hole 3a) of the long groove 3b comes into contact with the engagement shaft 1b, the turning angle of the magnet rotor 2 becomes smaller. The same applies to the second light shielding blade 4.

  FIG. 3 shows the relationship between the light shielding blade drive shaft 2 a of the rotor magnet 2 and the first light shielding blade 3 and the second light shielding blade 4. This state shows the fully opened state shown in FIG. 1A, and the long groove 3b of the first light shielding blade 3 and the long groove 4b of the second light shielding blade 4 are the first long groove portions 3e and 4e and the second long groove portions 3f and 4f. The third long groove portions 3g and 4g are connected to each other so as to have a plurality of inflection points.

  In short, in this embodiment, the turning angle of the rotor magnet 2 and the first light shielding blade 3 and the second light shielding blade 4 move from the fully open state shown in FIG. 1A to the light shielding completion shown in FIG. 1C. The rate of movement is changed at the above inflection point.

  That is, the turning region of the rotor magnet 2 from when the first light shielding blade 3 and the second light shielding blade 4 are fully opened as shown in FIG. 1A to when the light shielding starts as shown in FIG. The turning area of the rotor magnet 2 from the start of light shielding shown in (b) to the time when the opening hole 1c is shielded is the second turning area, and the rotor magnet 2 from the light shielding of the opening hole 1c to the completion of light shielding shown in FIG. Is the third turning area, the ratio of the moving amount of the first light shielding blade 3 and the second light shielding blade 4 to the turning angle from small to large before and after the transition from the first turning area to the second turning area. Further, before and after the transition from the second turning area to the third turning area, the ratio of the moving amount of the first light shielding blade 3 and the second light shielding blade 4 to the turning angle is changed from large to small. Yes.

  Then, comparing the first turning area and the second turning area, in order to reduce the ratio of the movement of the light shielding blade to the turning angle of the rotor magnet 2 in the first turning area, the rotor magnet 2 turns at a predetermined angle. In order to increase the ratio of the movement of the light-shielding blade to the turning angle of the rotor magnet 2 in the second turning region, the amount of movement of the light-shielding blade at the time of rotation of the rotor magnet 2 may be reduced. It is sufficient to increase the amount of movement of the light shielding blade. Then, in the first turning area, the light shielding blade starts to move slowly, and accelerates rapidly when the second turning area is entered beyond the first turning area.

  Further, comparing the second turning area and the third turning area, in the second turning area, in order to increase the ratio of the movement of the light shielding blades relative to the turning angle of the rotor magnet 2, as in the case described above, the rotor magnet is used. In order to increase the amount of movement of the light-shielding blade when 2 turns around a predetermined angle and reduce the ratio of movement of the light-shielding blade to the turning angle of the rotor magnet 2 in the third turning region, the rotor magnet 2 What is necessary is just to make small the movement amount of the light-shielding blade at the time of turning an angle. If it does so, it will decelerate when the light-shielding blade which was turning at high speed passes the 2nd turning area and enters the 3rd turning area, and finally hits the stopper and stops.

  In this embodiment, the turning angle of the rotor magnet 2 is changed without changing the moving amount of the light shielding blade in each of the first turning area, the second turning area, and the third turning area. The turning angle of the rotor magnet 2 in the first turning area and the third turning area is increased, and the turning angle of the rotor magnet 2 in the second turning area is reduced.

  In the present embodiment, the first long groove portions 3e and 4e have a predetermined turning angle of the rotor magnet 2 from when the rotor magnet 2 starts to turn until the opening hole 1c shown in FIG. The first light-shielding blade 3 and the second light-shielding blade 4 are formed in such directions that the amount of movement is small, that is, in the concave shape described above. That is, when the rotor magnet 2 turns in the light shielding direction, the inner peripheral edge (convex inner peripheral edge) closer to the round hole 3a, 4a comes into contact with the engagement shaft 1b in the first long groove portions 3e, 4e. The first light-shielding blade 3 and the second light-shielding blade 4 have a small movement in the light-shielding direction (for example, compared to the straight inner periphery).

  Next, the second long groove portions 3f and 4f move the first light shielding blade 3 and the second light shielding blade 4 with respect to a predetermined turning angle of the rotor magnet 2 from the light shielding start to the light shielding completion shown in FIG. Each is formed in such a direction that the amount increases, that is, the convex shape described above. That is, when the rotor magnet 2 turns in the light shielding direction, the inner peripheral edge (concave inner peripheral edge) closer to the round holes 3a and 4a comes into contact with the engagement shaft 1b in the second long groove portions 3f and 4f. The amount of movement in the light-shielding direction between the first light-shielding blade 3 and the second light-shielding blade 4 is large (compared to the case where the first long groove portions 3e and 4e are moved).

  Accordingly, when the first long groove portions 3e and 4e are in contact with the engaging shaft 1b, the light shielding blade is accelerated slowly, and when the first long groove portions 3e and 4e are in contact with the second long groove portions 3f and 4f beyond the inflection point, the light shielding blade accelerates rapidly. Will be.

  The third long groove portions 3g and 4g have the first light shielding blade 3 with respect to a predetermined turning angle of the rotor magnet 2 from the completion of light shielding to the opening hole 1c shown in FIG. And the direction in which the movement amount of the second light shielding blade 4 is reduced, that is, the concave shape described above. That is, when the rotor magnet 2 turns in the light shielding direction, the third long groove portions 3g and 4g abut on the inner peripheral edge (convex inner peripheral edge) closer to the round holes 3a and 4a with respect to the engagement shaft 1b. The amount of movement in the light shielding direction between the first light shielding blade 3 and the second light shielding blade 4 is small (compared to the case where the second long groove portions 3g and 4g are moved).

  Accordingly, when the second long groove portions 3f and 4f are in contact with the engagement shaft 1b, the light-shielding blade moves at a high speed, and when the second long groove portions 3f and 4f are in contact with the third long groove portions 3g and 4g beyond the inflection point, they are rapidly decelerated. Will be.

  In the open state shown in FIG. 1A, the first light shielding blade 3 and the second light shielding blade 4 are in contact with the engagement shaft 1b at the end 3c of the long groove 3b and the end 4c of the long groove 4b. Further, in the light shielding state shown in FIG. 2, the end 3d of the long groove 3b and the end 4d of the long groove 4b are in contact with the engagement shaft 1b.

  The above is the configuration of the present embodiment. The operation of the light amount adjusting device will be described below with reference to FIGS. 1, 2, 3, and 4. FIG.

  When the energization of the electromagnetic coil 6 is OFF, the stator yoke 5 is in a non-excited state, and the rotor magnet 2 whose outer peripheral surface is magnetized to two poles (N pole, S pole) is opposed to the stator yoke. 5 is held in the blade position state of FIG. 1 (a) or FIG. 2 by the attracting force (detent force) with the magnetic pole portions 5a and 5b.

  In the open state shown in FIG. 1A, the first light-shielding blade 3 and the second light-shielding blade 4 contact the end 3c of the long groove 3b and the end 4c of the long groove 4b against the engagement shaft 1b provided on the base plate 1. This open state is maintained by being magnetically attracted in the direction of contact.

  From this state, when the coil 6 is energized so that the magnetic pole portion 5a of the stator yoke 5 becomes the N pole and the magnetic pole portion 5b becomes the S pole, a repulsive force is generated between the stator yoke 5 and the rotor magnet 2. The rotor magnet starts to rotate in the clockwise direction from the state of FIG. 1, and when it passes through the magnetic intermediate point, it switches to the attractive force and rotates about 36 ° (see FIG. 2).

  The light shielding blade drive shaft 2 a provided integrally with the rotor magnet 2 moves integrally with the rotor magnet 2. Thereby, the 1st light-shielding blade 3 and the 2nd light-shielding blade 4 rotate from the open state to the light-shielding state which shielded the opening hole 1c of FIG.

  In the above operation process, the first length of the long groove 3b provided in the first light shielding blade 3 is from the start of the rotor magnet 2 until the first light shielding blade 3 and the second light shielding blade 4 begin to shield the opening hole 1c. Regulated by the groove 3e and the first long groove 4e of the long groove 4b provided in the second light shielding blade 4, the rotor magnet 2 requires a large turning (about 15 °) and is sufficiently accelerated. That is, the first long groove portions 3e and 4e have a function of accelerating the blade driving means and facilitating acceleration of the light shielding blade.

  When the rotor magnet 2 further turns, the rotor magnet 2 is regulated by the second long groove portion 3f of the long groove 3b provided in the first light shielding blade 3 and the second long groove portion 4f of the long groove 4b provided in the second light shielding blade 4, respectively. The opening hole 1c is shielded from light abruptly by turning (about 13 °). For this reason, the time from the start of light shielding to the completion of light shielding can be shortened. The second long groove portions 3f and 4f cover an area that shields the opening hole 1c.

  Thereafter, when the rotor magnet 2 further turns, the rotor magnet 2 is turned by being restricted by the third long groove portion 3g of the long groove 3b provided in the first light shielding blade 3 and the third long groove portion 4g of the long groove 4b of the second light shielding blade 4. The amount of movement of the first and second light shielding blades 3 and 4 is smaller than (about 8 °), and the end 3d of the long groove 3b provided in the first light shielding blade 3 is provided in the second light shielding blade 4 again. The end 4d of the long groove 4b comes into contact with the engagement shaft 1b, and the rotor magnet 2 stops turning.

  And the first light shielding blade 3 and the second light shielding blade 4 bounce at the time of contact, but since the movement amount of the first and second light shielding blades 3 and 4 is small, this bounce can be suppressed to be small, It is possible to prevent re-exposure from occurring due to the opening being formed in the opening hole 1c. That is, the third long groove portions 3g and 4g have a function of absorbing bounds.

  Even if the power supply to the electromagnetic coil 6 is turned off in this state, the state is maintained by the magnetic attraction of the rotor magnet 2 and the stator yoke 5 as described above.

  Thereafter, when the electromagnetic coil 6 is energized so that the magnetic pole portion 5a of the stator yoke 5 becomes the S pole and the magnetic pole portion 5b becomes the N pole, a repulsive force and an attractive force are generated between the stator yoke 5 and the rotor magnet 2. The rotor magnet 2 turns counterclockwise and returns to the initial position. As a result, the first and second light shielding blades 3 and 4 also return to the initial positions. In this manner, the light-shielding blades 3 and 4 perform light-shielding and opening operations under the action of the magnetic attractive force and the repulsive force due to forward and reverse energization of the coil 6.

  On the other hand, in the conventional example shown in FIGS. 6 and 7, the turning angle of the rotor magnet 12 from the open state to the start of light shielding is about 9 °, whereas in this embodiment, the rotor magnet is about 15 °. Since the turning angle of 2 is large, the light shielding blade of the conventional example shown in FIGS. 6 and 7 has a small acceleration for turning the first and second light shielding blades 3 and 4 of this embodiment.

  Further, the turning angle of the rotor magnet 12 from the start of light shielding to the completion of light shielding shown in FIGS. 6B and 6C showing the conventional example was about 20 °.

  In contrast, in this embodiment, the turning angle of the rotor magnet 2 from the start of light shielding to the completion of light shielding shown in FIGS. 1B and 1C was about 13 °.

  Thus, the turning angle (about 20 °) of the rotor magnet 12 between the start of light shielding and the completion of light shielding in the conventional example is compared with the turning angle (about 13 °) of the rotor magnet 2 in the same section in this embodiment. It takes a long time to shield light. Further, the turning angle of the rotor magnet 12 from the completion of the light shielding shown in FIG. 6C to the light shielding completion stopped state shown in FIG. 7 is about 7 °, and the turning angle of the rotor magnet 2 in the same section of this embodiment is about 7 °. Since the angle is smaller than 8 °, in the conventional example, the angle bounced back to the original light shielding completion position is small, which is disadvantageous for re-exposure due to bounce. On the other hand, in the present embodiment, a margin for preventing re-exposure due to the bounce is obtained by the amount of the turning angle required from the completion of the light-shielding to the stop state of the completion of the light-shielding, thereby preventing re-exposure due to the bounce. be able to.

  When the above operation is repeated, the end portions 3c, 3d and 4c, 4d forming both ends in the longitudinal direction of the long grooves 3, 4 provided in the first and second light shielding blades 3, 4 for stopping the turning are engaged. The collision is repeated on the shaft 1b. Therefore, in the present embodiment, the end portions of the long grooves 3 and 4 are formed in a semicircular shape, the engagement shaft 1b that contacts the long hole is formed in a columnar shape, and the first and second light shielding blades 3 and 4 are open or When stopping on the light shielding side, the ends of the long grooves 3 and 4 are in contact with each other. As a result, the contact surface between the light-shielding blade and the engagement shaft is widened, so that no obstructive crushing occurs. This makes it possible to use thinner and lighter light shielding blades.

  Furthermore, by restricting the turning of the light-shielding blade by the engagement shaft 1b, which is one of the restricting members provided on the base plate 1, and also functioning as a stopper for the turning, the device without providing restricting members and stoppers at other locations. Can be configured and the size can be reduced.

Compared with this, when the rotor magnet 12 stops turning when the rotor magnet 12 is in the open state and the light shielding state, the light shielding blade drive shaft 12a is placed on the flat end face of the long groove 13b of the light shielding blade 13 and the long groove 14b of the light shielding blade 14. Collide and stop. As described above, since the light shielding blade drive shaft 12b collides with a flat surface, if a thin light shielding blade is used, the end surfaces of the long grooves 13b, 14b are crushed and obstructed, and the thin light shielding blade cannot be employed.
(Second embodiment)
FIG. 5 shows a second embodiment of the present invention. FIG. 5 is a schematic diagram of an optical imaging apparatus.

  FIG. 5 shows an example in which the light amount adjusting device 100 of the above-described embodiment is applied to an optical imaging device 101 such as a digital camera or a digital video camera. The lens unit 102 having an imaging optical system is equipped with the light amount adjusting device 100. The subject light that has passed through the light amount adjusting device 100 is imaged on the image sensor 103, and an appropriate image can be obtained even when shooting a high-luminance subject or moving subject.

The light quantity adjustment apparatus which is 1st Example of this invention is shown, (a) is a top view of an open state, (b) (c) is a figure which shows the light-shielding process of a light-shielding blade. The figure which shows the light-shielding side stop state of the light quantity adjustment apparatus which is 1st Example of this invention. The figure which shows the light-shielding blade | wing of FIG. 1, FIG. Sectional drawing of the light quantity adjustment apparatus shown to FIG. 1, FIG. The figure which shows 2nd Example of this invention. FIG. 2 shows a conventional light amount adjusting device, (a) is a plan view in an open state, and (b), (c) are diagrams showing a light shielding process of a light shielding blade. The figure which shows the conventional light quantity adjustment apparatus (light-shielding side stop state).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground plate 1a Support shaft (magnet rotating shaft) 1b Engagement shaft 1c Opening hole 1e Recessed part 2 Rotor magnet (cylindrical permanent magnet)
2a light shielding blade drive shaft 2b round hole 3 first light shielding blade 4 second light shielding blade 3a, 4a round hole 3b, 4b long groove 3c, 3d, 4c, 4d long groove end portion 3e, 4e first long groove portion 3f, 4f second long Grooves 3g, 4g Third long groove 5 Stator yoke 5a, 5b Stator yoke magnetic pole 6 Electromagnetic coil 7 Cover plate 100 Shutter device 101 Optical imaging device 102 Lens barrel unit 103 Image sensor 11 Ground plate 11a of conventional light quantity adjusting device (Magnet rotation shaft) 11b Engagement shaft 11c Opening hole 11d Stopper shaft
12 Rotor magnet (cylindrical permanent magnet) of conventional light quantity control device
12a light shielding blade drive shaft 12b round hole 13 first light shielding blade 13a round hole 13b long groove of conventional light quantity adjusting device
14 Second light shielding blade of conventional light amount adjusting device 14a Round hole 14b Long groove
DESCRIPTION OF SYMBOLS 15 Stator yoke 15a, 15b of conventional light quantity adjustment apparatus Magnetic pole part 16 of stator yoke Electromagnetic coil of conventional light quantity adjustment apparatus

Claims (5)

A plurality of light shielding blades for controlling incident light; a ground plate having an opening for allowing the incident light to pass therethrough; and a driving source attached to the ground plate for moving the light shielding blades. A blade driving means for moving the light shielding blade along a predetermined locus by a driving force of the drive source; and a regulating member provided on the base plate for restricting the movement of the light shielding blade. Is a light amount adjusting device that rotates with the contact position as a turning fulcrum while shifting the contact position with the restricting member in response to the movement by the blade driving means and the restriction member,
The blade driving means rotatably supports the at least one light shielding blade, and the light shielding blade regulates the turning direction of the light shielding blade by contact with the regulating member according to the movement of the blade driving means. A light amount adjusting device comprising a long groove provided with a plurality of bent portions.   The plurality of bent portions of the light-shielding blade are inflection points at portions where the light-shielding blade is in contact with the restriction member at least before the shield plate starts to shield the opening of the base plate and after the opening is shielded. The light quantity adjusting device according to claim 1, wherein:   The inflection point is that the rotation angle of the blade driving means and the movement ratio of the light shielding blade change from small to large before the light shielding blade starts to shield the opening of the ground plate, and the opening is shielded. The light amount adjusting device according to claim 2, wherein the light amount adjusting device is formed so as to change from large to small after.   The shape of both end portions of the bent long groove of the light shielding blade is substantially the same as the shape of the portion of the regulating member that contacts at least the end portion of the long groove. The light amount adjusting device according to claim 1, wherein the light amount adjusting device stops when the end portion and the restricting member come into contact with each other.   5. An optical imaging apparatus comprising: the light amount adjusting device according to claim 1; and an imaging unit that forms an image of subject light that has passed through the light amount adjusting device.

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