JP4883385B2 - Optical element protection device and imaging device - Google Patents

Description

  According to the present invention, in a protection device or an imaging device having a barrier blade for protecting an optical element such as a lens, the optical element is reliably secured by always closing the opening facing the optical element when the power is not supplied. The present invention relates to a technology that protects and does not involve complicated mechanisms and configurations, and is suitable for power saving.

  Various barrier mechanisms have been proposed as means for protecting optical elements such as lenses.

  An imaging device or the like is provided with a barrier mechanism for protecting the lens. For example, the barrier member has a two-blade structure, and the barrier blade is moved manually or by driving means using an actuator to close or open the opening. The structure which performs is known (for example, refer patent document 1).

  In the configuration in which the position of the barrier blade is detected using a mechanical switch, the energization control of the actuator is performed by detecting the open end position and the closed end position of the barrier blade. For example, when the camera is switched to the shooting mode by a control means using a microcomputer or the like, the actuator is operated to move the barrier blade to the open end position, and when the opening is fully opened, the mechanical switch When it is detected that the contact point is closed, the movement of the movable blade is stopped. On the other hand, at the end of the shooting mode, by operating the actuator, the barrier blade is moved to the closed end position, and when it is detected that the contact of the mechanical switch is closed when the opening is fully closed, The movement of the movable blade is stopped.

  When such a lens protection device is mounted on a portable imaging device or the like, not only miniaturization and space saving, but also a simple mechanism and configuration and a minimum number of parts are required.

JP 2004-139032 A

  By the way, the conventional apparatus has the following problems with respect to the reliability of driving and holding the barrier blades.

  For example, when a user's finger or foreign object touches the barrier blade of the lens barrier device, or when strong vibration or external force is applied, the opening is inadvertently opened or the barrier blade is not fully open. If it does not close, there is a risk that lens protection measures will be insufficient.

  In such a case, it is sufficient to control the drive so that the barrier blade is moved by energizing the actuator so as to close the opening. However, in application to a portable device, always performing the closing operation by energizing saves power. There are inconveniences such as contrary to the request. Alternatively, it is preferable that the opening is closed by the barrier blade even when the battery is exhausted. For that purpose, a mechanical biasing means such as a tension coil spring is provided to bias the opening in the closing direction by the barrier blade. Then, the number of parts increases, which hinders downsizing and cost reduction. Alternatively, when opening the opening, it is necessary to generate a driving force against the urging force, which causes an increase in power consumption.

  In the protection device for an optical element such as a lens, the barrier blade is moved in a direction to close the opening when no current is applied, so that the opening is not left open due to unexpected vibration or external force. This is the issue.

  In order to solve the above-described problems, the present invention drives a drive unit having a stator unit including a coil and a magnetic core and a rotor unit including a magnet, and closing or opening an opening facing the optical element. The movable vane is moved in the closing direction for closing the opening or the opening direction for opening the opening by the driving force of the part, and has the following configuration.

  When the coil is energized, the first position where the opening is closed by the movable blade, and the second position where the movable blade is moved in the opening direction further than the position where the opening is not blocked by the movable blade and is fully opened. And being moved by the drive unit.

・ When the coil is not energized, the movable blade is moved in the direction to close the opening by the holding torque (static torque) of the drive unit, and the rotation position of the rotor unit when the holding torque is minimized is used as the reference position. The rotation range of the rotor portion in the closing direction is larger than the rotation range of the rotor portion in the opening direction, and the reference position is between the first position and the second position. The opening is fully opened at the third position in the closing direction.
A plurality of salient poles are formed on the magnetic core around which the coil is wound, the opposing surfaces of the salient poles are parallel to each other, and the magnet is positioned between the opposing surfaces in a rotatable state. is being done.
The magnetic core has a first part and a second part each having salient poles formed therein, and a third part that connects them, and is a coil wound around the first part. The coils wound around the second part are connected in series with each other and the winding directions of the coils are opposite.
-Position detection means for detecting the position of the movable blade moved between the first position and the second position, and control for controlling the drive unit according to the detection signal from the position detection means And a means for controlling the energization or non-energization state of the coil or limiting the energization amount according to the position of the movable blade detected by the position detection means.

  Therefore, in the present invention, the movable blade can be moved in the direction of closing the opening by using the holding torque (torque of the magnetic spring) generated when the coil is not energized. That is, even when the movable blade is moved by insertion of a user's finger or a foreign object, or even when the movable blade is moved by the action of vibration or external force and the opening is opened, an urging means such as an elastic member is required. Without this, the movable blade can be moved in the closing direction of the opening by the force that the rotor portion tries to maintain the magnetic balance. Therefore, the mechanism necessary for moving the movable blade is simplified, and it is not necessary to energize the coil when moving the movable blade in the closing direction of the opening.

  According to the present invention, it is possible to prevent the opening from being inadvertently opened, and to sufficiently protect the optical element without complicating the configuration of the mechanism that moves the movable blade with respect to the opening. can do. In addition, the movable blade can be moved in the closing direction of the opening when there is no energization, so that no unnecessary power consumption is involved. In addition, since mechanical means for urging the movable blade in the closing direction of the opening is not required, the configuration is simplified, which is suitable for downsizing and thinning.

In the configuration of the drive unit in which a plurality of salient poles are formed on the magnetic core around which the coil is wound, the rotation center position of the rotor part including the magnet is shifted relative to the center axis of the salient poles. In order to eliminate the influence on the holding torque, the opposed surfaces of the salient poles are made parallel to each other, and the magnet of the rotor portion is positioned between the opposed surfaces in a rotatable state . In other words, even if the rotation center of the rotor part is slightly displaced in the direction parallel to the opposing surface of the salient pole due to variations in assembly accuracy, etc., it is guaranteed that the movable blade will always move in the direction to close the opening when there is no current. can do.

Further, in order to save space and reduce the size of the drive unit for moving the movable blade, the first and second parts each having salient poles are connected to each other as the shape of the magnetic core. The third part is integrally formed, and a coil is wound around each of the first part and the second part . And while the coil wound by the 1st part and the coil wound by the 2nd part are connected in series, the winding direction of each coil is made into the opposite direction. Compared to the configuration in which one coil is wound around the third part, it is more effective to prevent the coil from becoming thicker and to be compacted by winding the coil separately into the first and second parts. (The drive unit can be arranged by effectively utilizing the limited space around the movable blade.)

Position detection means for detecting the position of the movable blade moved between the first position and the second position, and control for controlling the drive unit in accordance with a detection signal from the position detection means In the configuration having the means, the energization or non-energization state of the coil of the drive unit is controlled or the energization amount is limited in accordance with the position of the movable blade detected by the position detection means . For example, in the form in which the intermediate area between the first position and the second position is detected by the position detection means, the intermediate area and the areas located on both sides thereof (close to the first position) The drive control can be performed by dividing the region into regions and regions close to the second position. That is, when the movable blade is moved to the first or second position through the intermediate region, the energization of the coil may be stopped by the control means or the energization amount may be limited.

  If the neutral region is defined as an intermediate region where the holding torque of the drive unit and the load torque applied to the rotor unit are balanced when the coil is not energized, the energization of the coil is stopped when the neutral region is passed, or the energization amount Can be sufficiently reduced, and the movable blade can be moved to the first position or the second position. Thereby, power consumption can be reduced, and it can prevent that the operation sound etc. by the impact in the terminal position of the movable range of a movable blade | wing do not generate | occur | produce.

  INDUSTRIAL APPLICABILITY The present invention is effective for downsizing, power saving, durability improvement, and the like when applied to a barrier device or the like that protects an optical element such as a lens.

  It is preferable to configure.

  The present invention relates to a barrier device for protecting a lens or the like from damage or fouling, or a protection device having a light shielding member or a blade member for shielding the opening to protect the imaging element or the like from high-intensity light. The lens or the like is exposed and exposed to external light in a state where the lens is left open. For example, the present invention can be widely applied to a still camera, a video camera, or various imaging devices that can capture still images and moving images.

  FIG. 1 is a schematic diagram illustrating a basic configuration example of a protection device 1 according to the present invention.

  An object to be protected is an optical element such as a lens or an image pickup element. For example, an objective lens 3 constituting the image pickup optical system 2 in application to an image pickup apparatus can be cited. Placed on top.

  A member 6 having an opening 5 is located in front of the imaging optical system 2 (left side in FIG. 1). Movable blades 7 and 7 are provided to close or open the opening 5 facing the optical element, and are moved by the driving means 8. That is, the movable blades 7 and 7 are moved by the driving means 8 in the closing direction for closing the opening 5 or moved in the opening direction for opening the opening 5. In the application of the present invention, the number of movable blades does not matter. The drive means 8 includes an actuator, a drive circuit, and the like, and the drive force generated by the actuator is transmitted to the movable blade via a relay member such as a drive ring described later, or the drive force of the actuator. Can be transmitted directly to the movable blade.

  The position detection means 9 is provided for detecting the position of the movable blade 7, and for example, a magnetic detection means using the Hall effect is used. In the detection mode using the mechanical switch as described above, a loss torque is generated by the switch, which causes a decrease in detection accuracy. Therefore, in order to guarantee the certainty of the operation even when the movable blade exists near the open end position or the closed end position, it is necessary to control with a large driving force with a margin in torque. As a result, a current with a large margin is allowed to flow through the actuator, leading to an increase in power consumption or a decrease in durability, and operating noise (movable blades at the open end position or the closed end position). The collision sound that occurs when you come to the In order to avoid such an inconvenience, it is desirable to use a magnetic sensor and perform actuator energization control as described later based on the detection signal of the sensor. In addition, the form which detects the position of the movable blade 7 magnetically, and the form which detects the position of the member (drive ring etc. which are mentioned later) which drive the movable blade 7 magnetically are mentioned.

  The control means 10 is provided to generate a control signal in response to the detection signal from the position detection means 9, send the signal to the drive means 8, and control the position of the movable blades 7, 7. A microcomputer or the like is used.

  FIG. 2 is a perspective view schematically showing an example of an external appearance when applied to a camera having a camera lens barrier mechanism, showing a configuration example of an imaging apparatus according to the present invention.

  The imaging device 11 shown in this example is provided with a lens protection device 14 (so-called lens barrier device) on the front surface portion 13 of the housing 12 thereof. The apparatus serves to prevent damage caused by finger contact with a camera lens or insertion of foreign matter, and includes a mechanism for rotating movable blades using a plurality of blade members and a driving means thereof, as will be described later. ing. That is, by changing the rotational state of the movable blade using the driving force of the actuator constituting the driving means, the state in which the opening 15 is completely closed (blocked state) using the blade member as a shielding member, and the blade The member is moved to a position where there is no optical influence, the opening 15 is completely opened, and the camera lens is exposed to the outside (opened state).

  An operation button 16 (such as a shutter release button) is provided on the side surface of the housing 12, and although not shown, a display unit such as a liquid crystal display panel is attached to the rear surface of the housing 12. ing.

  3 to 29 show a configuration example of the lens protection device 14 according to the present invention.

  3 to 5 show an example of the appearance of the protective device. FIG. 3 is a perspective view, FIG. 4 is a front view, and FIG. 5 is a rear view. 6 and 7 are exploded perspective views showing the structure of the protective device, FIG. 6 shows an exploded perspective view when seen from a slightly oblique front with the shooting direction as the front side, and FIG. 7 shows a slightly oblique view from the rear. The exploded perspective view of is shown.

  The front surface 17 of the lens protection device 14 is formed with an opening 15 having a substantially rectangular shape when viewed from the direction along the optical axis of the photographing lens system (optical system). In this example, two movable blades are used. For example, as shown in FIGS. 3 to 5, the opening 15 is closed by the mechanism, so that the lens inside the imaging apparatus is optically blocked from the outside.

  The lens protection device 14 uses a first component member 18, a drive unit 19, a pair of blade members 20 a and 20 b constituting the movable blade 20, a second component member 21, a drive ring 22, and a third component member 23. Configured.

  The first component member 18 is a member (barrier front) disposed in the foremost part (hereinafter, the imaging direction is defined as the front), and an opening 15 is formed in the member 18.

  The drive unit 19 is for moving the movable blade 20 by rotating the drive ring 22 around a predetermined axis by the drive force. The drive unit 19 includes the first component member 18 and the second component member 21. It arrange | positions in the accommodation space formed between. For example, a DC-type actuator is used, and a rotor part having a magnet and a stator part including a coil and a magnetic core are used as a driving source, as will be described later. The drive unit 19 is disposed on the substrate 24 (see FIGS. 6 and 7), and a part of the drive unit 19 is provided on the back surface of the first component 18 for wiring with an external circuit including a control circuit. A flexible connection member 25 (flexible printed wiring material or the like) with other portions drawn out of the protective device casing is used to control energization of the coil.

  The blade members 20a and 20b are attached to the back surface of the first component member 18 in a rotatable state. That is, each blade member is supported in a rotatable state while being sandwiched between the first component member 18 and the second component member 21, and the rotational force of the drive ring 22 is applied to each blade member. Is transmitted to. When both members 20a and 20b are close to each other, the opening 15 is closed, and as both members are rotated and separated from each other, the opening 15 is gradually opened and the opening 15 is completely opened. .

  The second component member 21 supports the drive unit 19 and the blade members 20 a and 20 b with the first component member 18, and can rotate the drive ring 22 with the third component member 23. It is a member (barrier base) supported in a state. A relatively large central circular hole is formed in the second component member 21, and part of the blade members 20 a and 20 b (engagement protrusions) is inserted into a part of the drive ring 22 (engagement notch). A long hole or the like for engagement is formed (the specific shape will be described in detail later).

  The drive ring 22 is disposed in a space formed between the second component member 21 and the third component member 23, and receives a drive force from a movable member (an arm member described later) constituting the drive unit 19. Is rotated. The rotational force of the drive ring 22 is transmitted to the blade members 20a and 20b, and the opening state is defined according to the rotation position of the ring. In the configuration for detecting the rotation angle of the drive ring 22, for example, a magnetic field generating means 26 such as a position detection magnet is attached to the drive ring 22, and a magnetic detection means 27 such as a Hall IC is provided as the rotation detection means. (See FIG. 7).

  The third component member 23 serves as a cover member in order to accommodate the drive ring 22 between the second component member 21 and rotatably support the ring. A central circular hole is formed in the third component member 23, and an attachment portion to the second component member 21 is provided.

  Note that screw members 28 and 28 are used for coupling the first component member 18 and the second component member 21, and in this example, each screw member is formed in a hole formed in the second component member 21. Then, the two constituent members are fastened by screwing into the screw holes formed in the first constituent member 18. Further, screw members 29 and 29 are used for coupling the second component member 21 and the third component member 23, and in this example, the engagement protrusions formed on the second component member 21 are the first ones. The screw holes formed in the second component member 21 are inserted into the engagement holes formed in the third component member 23 and the screw members are inserted into the holes formed in the third component member 23. Both components are fastened by screwing together. Needless to say, the present invention is not limited to this example but can be implemented in various forms such as fitting, insertion, and engagement.

  Next, the configuration of each unit will be described with reference to FIGS.

  FIGS. 8 and 9 show examples of the shape of the first component member 18, FIG. 8 is a front view, and FIG. 9 is a perspective view seen obliquely from the rear.

  The first component 18 is integrally formed using a synthetic resin or the like, and a range 30 shown in a substantially circular frame in FIG. 8 is slightly depressed, and an opening 15 is formed in the range.

  The opening 15 has a shape close to a rectangle, and among the opening edges, the upper edge 15U and the lower edge 15D in FIG. 8 are straight lines parallel to each other, and the left edge 15L and the right edge 15R are straight lines parallel to each other. The four corners 15C, 15C,... Are arcuate. The optical axis of the imaging optical system (not shown) is set so as to extend in the direction perpendicular to the paper surface of FIG.

  In the peripheral edge portion of the first component member 18, arc-shaped cutouts 31, 31,... (Three places in this example) are formed.

  On the rear surface of the first component member 18, as shown in FIG. 9, a protrusion 32 is suspended from the upper left portion so as to face the rear, and the blade member 20b is pivotally supported by the protrusion 32 (that is, The projection 32 has a function as a pivot of the one blade member 20b.).

  A protrusion 34 facing inward is formed on the inner surface of the outer peripheral wall 33 extending substantially downward from the left side of the protrusion 32, and the blade member 20 b described later comes into contact with the protrusion 34, thereby The blade member is regulated so as not to rotate any further.

  A screw hole 35 is formed between the protrusion 34 and the notch 31, and the screw member 28 is screwed together when the second component member 21 is fastened. And the outer peripheral wall 36 is formed in the lower side of the notch 31 shown on the left side of FIG. 9, and the outer peripheral wall 37 is formed in the position away below this.

  In FIG. 9, a protruding wall 38 is formed on the right side of the protruding portion 32. The protruding wall 38 extends from the left end to the right, then bends downward, and further extends obliquely downward to the right. An arcuate portion 38b extends obliquely upward to the right from the portion 38a. A portion 38a near the lower end of the protruding wall 38 defines one stop position (closed position of the opening 15) related to the blade member by a part of a blade member 20a described later coming into contact with the portion. . Further, the arc-shaped portion 38b has a role of slidingly contacting and guiding one end portion of the blade member 20a when rotating.

  A notch 31 is formed near the upper edge of the right end of the first component member 18, an outer peripheral wall 39 is formed on the right side thereof, and an outer peripheral wall 40 is formed at a slight distance below the outer peripheral wall 39. .

  A screw hole 41 is formed at a position near the lower end of the outer peripheral wall 40, and the screw member 28 is screwed when fastened to the second component member 21. In the outer peripheral wall 40, a protrusion 42 facing inward is formed slightly below the screw hole 41. When the blade member 20a is in contact with the protrusion 42, the blade member does not rotate any more. To be regulated.

  A notch 31 shown in the lower right of FIG. 9 is formed close to the lower part of the outer peripheral wall 40, and a projecting portion 43 is suspended downward and obliquely downward to the left. The blade member 20a is pivotally supported by the projection 43 (that is, the projection 43 has a function as a pivot shaft of the blade member 20a).

  The outer peripheral wall 44 extending from the lower position of the protrusion 43 has a left end located at a predetermined distance from the outer peripheral wall 37, and the outer peripheral wall 44, 37 has a protrusion 45 facing inward. , 45 are formed.

  A slightly recessed region 46 is formed above the outer peripheral walls 37 and 44, and the connection member 25 and the substrate 24 (see FIGS. 6 and 7) are disposed in the region. In the region 46, a protrusion 47 having a hole 47a is formed facing backward, and the engagement protrusions 48, 48 are directed rearward at a predetermined distance from the protrusion 47 to the left and right. Projected. The protrusion 47 is a bearing for supporting one end of an arm member (68) described later, and the engagement protrusions 48, 48 are used for mounting a magnetic core (59) described later. Further, as shown in FIG. 7, the insertion holes 24 a corresponding to the protrusions 47 and the insertion holes 24 b and 24 b corresponding to the engagement protrusions 48 and 48 are formed in the substrate 24 arranged in the region 46. In addition, notches 24c and 24c corresponding to the protrusions 45 and 45 are formed.

  As shown in FIG. 9, a projecting piece 49 projects rearward between the lower edge 15 </ b> D of the opening 15 and the upper right end of the region 46, and is on the lower right side of the region 46 on the right side of the region 46. The protrusion 50 is erected rearward. The protruding piece 49 defines one stop position (closed position of the opening 15) related to the blade member by a part of the blade member 20b coming into contact with the portion.

  10 to 13 show examples of the shape of the blade member constituting the movable blade 20. Since each blade member has the same shape, only one of them is shown in each drawing. FIG. 10 is a front view, FIG. 11 is a rear view, FIG. 12 is a side view, and FIG.

  As shown in FIGS. 10 and 11, in the blade member 20a (or 20b), a main portion 51 formed in a substantially triangular shape and a cylindrical end portion 52 are integrally formed of a synthetic resin or the like. .

  The end 52 is formed with a shaft hole 52a penetrating the central portion thereof, and the protrusion 32 or 43 formed in the first component member 18 is inserted into the shaft hole 52a, whereby the blade member is It is pivotally supported in a rotatable state.

  As shown in FIGS. 11 and 12, an engagement protrusion 53 facing rearward is formed at a position slightly apart in the vicinity of the end 52, and an engagement notch formed in the drive ring 22 described later. Is engaged. Further, a projection 54 slightly projecting slightly away from the end 52 is formed on the side surface portion of the main portion 51, and the projection 54 has the blade member to a position where the opening 15 is completely opened. This is a portion that abuts against the protrusion 34 or 42 formed on the outer peripheral wall of the first component 18 in the rotated state.

  As shown in FIGS. 10, 12, and 13, an arc-shaped portion 55 that slightly protrudes toward the front is formed at a position near the end on the front surface of the main portion 51, and this portion is a blade member. Is in sliding contact with the first component 18 in contact with the first component member 18. In addition, a stepped portion 56 is formed at the rotation end portion farthest from the end portion 52, and when the opening 15 is completely closed by each blade member, the stepped portion 56 is the first component member 18. The protruding wall 38 is in contact with a portion 38 a near the lower end of the protruding wall 38 and the protruding piece 49.

  As shown in FIG. 11, a hypotenuse 57 is formed at substantially the center of the peripheral portion extending substantially linearly in the main portion 51, and the portion includes two blade members 20 a and 20 b that are optical axes of the imaging optical system. It is arranged with a rotational symmetry of 180 ° around and is used as a reference for mutual alignment (biting position) in a state in which the opening 15 is completely closed by both members.

  14 and 15 are perspective views showing a state in which the blade members 20a and 20b are attached to the rear surface of the first component member 18 from the rear side, and FIG. 14 shows a state in which the opening 15 is closed. Indicates a state in which the opening 15 is opened.

  As shown in the drawing, the blade member 20b disposed on the left side when viewed from the rear is in a state of being freely rotatable to the first component member 18 by inserting the protrusion 32 into the shaft hole 52a of the end portion 52 thereof. The other blade member 20a that is supported on the right side and disposed on the right side as viewed from the rear is rotated by the first component member 18 by the protrusion 43 being inserted into the shaft hole 52a of the end portion 52 thereof. It is supported in a free state.

  And in the obstruction | occlusion state of the opening 15 shown in FIG. 14, each blade member 20a, 20b is arrange | positioned with the rotational symmetry around the axis | shaft which passes along the center of the opening 15 and extends perpendicularly | vertically to a paper surface. Both blade members are in contact with each other without a gap, and the oblique sides 57 of each other are engaged in the center of the opening 15. In this state, when viewed from the rear, the stepped portion 56 formed on the left blade member 20b contacts the protruding piece 49 of the first component member 18 and is formed on the right blade member 20a. The stepped portion 56 is in contact with a portion 38 a of the first component member 18 near the lower end of the protruding wall 38.

  In the open state of the opening 15 shown in FIG. 15, when viewed from the rear, the blade member 20 b located on the left side is rotated in the clockwise direction, and the protrusion 54 formed on the blade member is the first component member 18. Is in contact with the protrusion 34 of the outer peripheral wall 33. Further, the blade member 20 a located on the right side is rotated in the clockwise direction, and the protrusion 54 formed on the blade member is in contact with the protrusion 42 of the outer peripheral wall 33 of the first component 18. In this state, a part of the main part 51 of the blade member 20b slightly protrudes from between the outer peripheral walls 36 and 37 of the first component member 18 to the outside. A part of the main portion 51 slightly protrudes from between the outer peripheral walls 39 and 40 of the first component 18 to the outside.

  As will be described later, with respect to the rotation of the blade members, the engaging projections 53 and 53 are respectively engaged with the engagement notches of the drive ring 22, and the blade members are brought into contact with each other as the drive ring 22 rotates. It is rotated between the contacted position and the position where each blade member is most separated.

  16 to 20 show a configuration example of the drive unit 19, which has a stator unit including a coil and a magnetic core, and a rotor unit including a magnet and an arm member. 16 and 17 show the stator part, and FIGS. 18 to 20 show the rotor part.

  16 is a view of the stator portion 58 as seen from the rear, and FIG. 17 is a bottom view of the stator portion 58.

  As shown in FIG. 16, the magnetic core 59 has a substantially bilaterally symmetric shape, and includes a first portion 59a and a second portion 59b each having a salient pole portion, and a third portion connecting them. 59c is integrally formed. The salient poles 60, 60 are formed in a direction approaching each other from the ends of the portions 59a, 59b, and both of the facing surfaces 60a, 60a are flat (flat surfaces) (the reason will be described later). To do.)

  The magnetic core 59 is formed by laminating and bonding a large number of magnetic materials having the same shape. A circular hole 61 is formed at a position near the upper end of the left portion 59a in FIG. 16, and a coil 62A indicated by a two-dot chain line is wound around the portion 59a. Further, an oval long hole 63 is formed at a position near the upper end of the right portion 59b of FIG. 16, and a coil 62B indicated by a two-dot chain line is wound around the portion 59b. One of the engaging protrusions 48 and 48 of the first component 18 is inserted into the circular hole 61, and the other of the engaging protrusions 48 and 48 is inserted into the long hole 63, whereby the magnetic core 59 is positioned and supported.

  The coil 62A wound around the portion 59a and the coil 62B wound around the portion 59b are connected in series with each other, and the winding directions of the coils are opposite. That is, the winding direction of each coil is as shown in FIG. 17, the left coil 62A is clockwise as indicated by arrow CW, and the right coil 62B is indicated by arrow CCW. The counterclockwise direction is assumed. In FIG. 16, the end 64 of the coil 62A is the winding start end, and the end 65 of the coil 62B is the winding end. After winding the coil 62A around the core portion 59a, the outside of the bridging portion 59c of the magnetic core is removed. A part of the winding is wound around the surface, and the coil 62B is wound around the core 59b (a part of the winding is fixed within a predetermined range of the bridging portion 59c by adhesion).

  18 and 19 show examples of the configuration of the rotor section 66. FIG. 18 is a perspective view, and FIG. 19 is a side view. In these figures, the cylindrical magnet 67 is distinguished by a two-dot chain line. Yes.

  The magnet 67 having the center hole is formed using sintered neodymium or the like, and is, for example, dipolar magnetized in the circumferential direction. The magnet 67 is attached to the center hole 67 a by inserting the support shaft 69 of the arm member 68 into the center hole 67 a, and is disposed between the salient poles 60 and 60.

  In the arm member 68, a disk-shaped main portion 70 and an arm portion 71 protruding in a crank shape from the portion are integrally formed of synthetic resin or the like. The support shaft 69 is suspended from the main portion 70, and the portion of the support shaft 69 to which the magnet 67 is attached is relatively long. As shown in FIG. 19, the shaft end 72 on the opposite side of the portion is provided. Is shorter. A concave portion 73 is formed around the position where the shaft end portion 72 is formed in the main portion 70 (see FIG. 19), and the shaft end portion 72 is used for a bearing formed in the first component 18. The arm member 68 is supported in a rotatable state by being inserted into the hole 47a of the protrusion 47. Further, the tip end portion of the support shaft 69 is supported by a bearing portion of the second component member 21 described later.

  A protruding portion 74 is formed integrally with the arm portion 71, and the protruding direction of the protruding portion 74 is parallel to the central axis direction of the support shaft 69.

  FIG. 20 shows the stator portion 58 and the rotor portion 66, and a magnet 67 of the rotor portion 66 is disposed between the salient poles 60 and 60 of the magnetic core 59 with a predetermined air gap (magnet 67). The gap length between the outer peripheral surface of each of the salient poles 60 and the opposing surface 60a of each salient pole 60 is made equal.

  In the figure, the N pole and S pole symbols are attached to the magnet 67 that is two-pole magnetized, and the neutral line “nl” that passes through the boundary between the magnetic poles is indicated by a one-dot chain line (the state shown in the figure). Then, the neutral line nl is at a position substantially perpendicular to the facing surface 60a of each salient pole 60).

  The arm member 68 to which the magnet 67 is fixed is rotatable about the support shaft 69 in the direction indicated by the arrow “θ” in the drawing, and the rotor member 66 of the rotor portion 66 depends on the energization direction of the coils 62A and 62B. The direction of rotation is determined.

  As will be described later, the rotational force of the rotor portion 66 is transmitted from the protrusion 74 of the arm member 68 to the drive ring 22 to rotate the drive ring.

  21 to 24 show examples of the shape of the second component member 21. FIG. 21 is a front view, FIG. 22 is a rear view, FIG. 23 is a partial sectional view, and FIG. It is the perspective view seen from.

  The second component member 21 is integrally formed using a synthetic resin or the like, and a circular hole 75 having a relatively large diameter is formed as shown in FIGS.

  Several mounting holes 76, 76,... Are formed at positions near the outer peripheral edge of the second component member 21. These mounting holes 76 are necessary for fixing the lens protection device 14 to the housing 12, and the formation positions thereof correspond to the formation positions of the notches 31, 31,... Of the first component member 18, respectively. For example, in FIG. 21, attachment holes 76 are formed in the upper left edge 77, the lower left edge 78, and the portion 79 near the right end, respectively.

  In FIG. 21, a long hole 80a is formed at a position slightly diagonally below and to the left of the circular hole 75, and an engagement protrusion 53 formed on one blade member 20a passes through the long hole 80a and will be described later. 22 is connected. And the edge part of the protrusion 43 provided in the said 1st structural member 18 is inserted in the hole 81a formed in the diagonally left downward position from the long hole 80a. A long hole 80b is formed on the opposite side to the long hole 80a across the center of the circular hole 75 at a position slightly above and to the right of the circular hole 75, and is formed in the other blade member 20b. The engagement protrusion 53 thus formed is coupled to the drive ring 22 described later through the long hole 80b. A hole 81b is formed at a position near the upper right edge that is slightly separated from the long hole 80b, and an end of the protrusion 32 provided in the first component 18 is inserted. .

  A relief hole 82 is formed below the circular hole 75. This hole is formed in order to avoid the rotation range of the arm portion 71 of the arm member 68, and a protrusion 74 formed on the arm portion 71 is connected to the drive ring 22 described later through this hole 82. An accommodation portion 83 of the drive unit 19 is provided below the escape hole 82, and the rotor portion 66 and the stator portion 58 described above are contained in an accommodation space defined between the first component member 18 and the accommodation portion 83. Is placed.

  For example, the accommodating portion 83 is formed with a bearing portion 84 for supporting the distal end portion of the support shaft 69 of the arm member 68, and the distal end portion of the support shaft 69 is inserted into the bottomed hole 84a (see FIG. 23). The rotor portion 66 is pivotally supported in the inserted state. Also, portions 85 and 85 are formed for accommodating portions (coil portions) obtained by winding the coils 62A and 62B around the magnetic core 59, respectively.

  On the rear surface of the component member 21 shown in FIG. 22, a first peripheral wall (or annular rib) 86 having a diameter slightly larger than the circular hole is suspended around the circular hole 75. A second peripheral wall 87 having a larger diameter is formed so as to surround the periphery of the peripheral wall 86, and the walls near the upper end are flat portions 88 and 88. A drive ring 22 (described later) is housed in a rotatable state within a range surrounded by the first and second peripheral walls. When viewed from the rear, the elongated holes 80a and 80b and the escape holes are removed. The hole 82 is arranged in the range. Note that the configuration for supporting the drive ring 22 in a rotatable state is not limited to this example, and various forms (a plurality of locations on the inner or outer peripheral portion of the drive ring are supported by pressing pieces or contact portions) Etc.) is possible.

  A positioning pin and a boss part project from the rear surface part located outside the second peripheral wall 87. For example, in FIGS. 22 and 24, a positioning pin 89 is formed on the left side of the peripheral wall 87, and a boss part 90 having a screw hole is provided below the peripheral wall 87, and a positioning pin 89 is provided on the right side of the peripheral wall 87. 91 is formed, and a boss portion 92 having a screw hole slightly above is suspended. These positioning pins and bosses are used when a third constituent member 23 described later is attached to the second constituent member 21.

  25 to 27 show examples of the shape of the drive ring 22. FIG. 25 is a front view, FIG. 26 is a rear view, and FIG. 27 is an exploded perspective view showing a state in which the position detecting magnet is removed. .

  The drive ring 22 is formed in a substantially annular shape using a synthetic resin or the like, and a circular hole 93 having a larger diameter than the outer diameter of the peripheral wall 86 of the second component member 21 is formed. Projections 94, 94,... Slightly projecting inward are formed on the inner peripheral surface of the circular hole 93. In this example, five protrusions are formed on the inner peripheral portion with a predetermined angular interval, and these are driven by coming into contact with the outer peripheral surface of the peripheral wall 86 formed on the second component member 21. This contributes to a reduction in frictional resistance when the ring 22 rotates.

  In FIG. 25, an arc-shaped protrusion 95 is formed immediately around a circular hole 93, and a part of the circle is cut out to be C-shaped. And about the circular-arc-shaped protrusions 96 and 97 formed in the position near an outer periphery so that this protrusion 95 may be surrounded, one 96 is arrange | positioned on the left side of a figure, and the other 97 is arrange | positioned on the right side. Has been. These protrusions are in contact with the member in a state where the drive ring 22 is positioned within the range surrounded by the first and second peripheral walls (86, 87) of the second component member 21. This contributes to a reduction in frictional resistance when the drive ring 22 rotates.

  In FIG. 25, an engagement notch 98 is formed near the upper end of the right ridge 97, and an engagement protrusion 53 formed on one blade member 20b is engaged with the engagement notch. . The protrusion 99 located on the left side of the engagement notch 98 is in contact with the inner surface of the flat portion 88 formed on the second component member 21 to restrict further rotation of the drive ring 22. It functions as a stopper protrusion for

  Another engagement notch 100 is formed at a position substantially opposite to the engagement notch 98 across the center of the circular hole 93, and the engagement notch is formed in the other blade member 20a. The protrusion 53 is engaged.

  An engagement notch 101 with which the protrusion 74 of the arm member 68 is engaged is formed at a position away from the engagement notch 100 at a predetermined angle in the counterclockwise direction of FIG. That is, the projecting portion 74 transmits the driving force of the rotor portion 66 to the drive ring 22 as an engagement shaft (or drive shaft), whereby the drive ring 22 rotates.

  Position detecting magnets 102 and 102 are formed slightly apart in the circumferential direction in the range between the engagement notches 100 and 101 and partially missing in the protrusion 95. That is, as shown in FIG. 27, the drive ring 22 has recesses 103, 103 for attaching magnets, and a tape magnet or the like is fixed in the recess by bonding or the like. A change in the position of the magnet accompanying the rotation of the drive ring 22 is detected using magnetic detection means such as a Hall IC, and a detection signal is sent to an external circuit (control circuit or the like) via the flexible connection member 25.

  As shown in FIG. 26, on the back surface of the drive ring 22, a circular ridge 104 is formed immediately around the circular hole 93, and an arc-shaped ridge 105 on the outer periphery thereof, 106 is formed. One protrusion 105 is disposed on the left side of FIG. 26, and its upper end reaches the vicinity of the engagement notch 98. The other ridge 106 is arranged on the right side of the ridge 104. These protrusions contribute to a reduction in frictional resistance during rotation of the drive ring 22 by being in contact with a third component member 23 described later.

  28 and 29 show examples of the shape of the third component member 23. FIG. 28 is a perspective view and FIG. 29 is a rear view.

  The third component member 23 is integrally formed using a synthetic resin or the like, and a circular hole 107 having the same diameter as the inner diameter of the circular hole 93 of the drive ring 22 is formed.

  In FIG. 28, a mounting portion 109 is formed on the outer peripheral edge portion 108 located on the left side of the third component member 23, and an insertion hole 111 is formed in the upper concave portion 110 of the mounting portion. An engaging hole 113 for positioning is formed in the recess 112. A mounting portion 115 is formed on the outer peripheral edge portion 114 located on the right side of the third component member 23, and an insertion hole 117 is formed in the lower concave portion 116 of the mounting portion, and the upper concave portion 118. An engagement hole 119 for positioning is formed inside. That is, when the third component member 23 is attached to the second component member 21 with the drive ring 22 sandwiched between the second component member 21 and the third component member 23 in a rotatable state. The tip of the positioning pin 89 formed in the second component 21 is engaged with the engagement hole 119 of the mounting portion 115 and the tip of the positioning pin 91 formed in the second component 21. Is engaged with the engagement hole 113 of the attachment portion 109. As a result, the third component member 23 is positioned with respect to the second component member 21, and then the screw members 29, 29 are inserted into the insertion holes 111, 117 of the mounting portions 109, 115, respectively. The second constituent member 21 is attached to the third constituent member 23 by screwing the screw shaft portions into the screw holes of the boss portions 90 and 92 formed in the second constituent member 21.

  In the lens barrier device described above, the drive unit 19 is provided between the first component member 18 and the second component member 21, and the drive force is driven from the arm member 68 as the rotational force of the drive ring 22. It is transmitted to the ring 22. Then, with the rotation of the drive ring 22 disposed between the second component member 21 and the third component member 23, the two blade members 20a and 20b are replaced with the first component member 18 and the second component member 18. It is rotated in the accommodation space between the component members 21. That is, when the blade members are in contact with each other, the opening 15 is closed by the main portions 51 and 51 of the blade members 20a and 20b, and each blade member is rotated to a position where it does not block the opening 15. In the state, the opening 15 is completely opened, and in the intermediate state, the opening area is defined according to the rotation position of each blade member.

  Next, the rotation of the drive ring 22 by the drive unit 19 and the movement of the movable blade 20 associated therewith will be described with reference to FIGS. 30 to 32.

  FIG. 30 shows a state in which the blade members of the movable blade 20 are rotated to the farthest positions and the opening 15 is completely opened. As shown in an enlarged view below, the support shaft of the arm member 68 is shown. The rotor portion 66 is rotated in a clockwise direction in the figure at a predetermined angle (see “+ θr” in the figure) with 69 as the rotation center axis (in this example, the reference axis of the rotation angle is the opening 15 The shaft is selected to extend in the vertical direction in the drawing through the center and the rotation center of the rotor portion 66). The drive ring 22 is rotated counterclockwise in the figure, and is rotated from the engagement protrusions 53 and 53 of the blade members 20a and 20b respectively engaged with the engagement notches 98 and 100 of the drive ring. Power is transmitted to each blade member, and the blade members 20a and 20b are rotated to a position where they do not block the opening 15.

  FIG. 31 shows the closed state of the opening 15, and as shown in an enlarged view below, the rotor has a predetermined angle (see “−θr” in the figure) with the support shaft 69 of the arm member 68 as the rotation center axis. The part 66 is in a state of being rotated counterclockwise in the drawing.

  The drive ring 22 is rotated in the clockwise direction in the figure, and the drive ring 22 rotates from the engagement protrusions 53 and 53 of the blade members 20a and 20b respectively engaged with the engagement notches 98 and 100 of the drive ring. Is transmitted to each blade member, and the blade members are brought into contact with each other.

  When the coils 62A and 62B of the stator portion 58 are energized, the rotation direction of the rotor portion 66 is defined according to the direction of the drive current, and the rotation direction of the drive ring 22 and thus the movable blade 20 is determined.

  When shooting is not performed or when the coil is not energized, the movable blade 20 is moved by the force with which the rotor portion 66 maintains a magnetically stable state, and the opening 15 is closed (fully closed position). . That is, when the coils 62A and 62B of the stator unit 58 are not energized, the moving direction of the movable blade 22 is defined by the holding torque (or stationary torque) of the driving unit 19, and the lens is protected and shielded in the fully closed state. The

  Further, when the coil is energized at the time of transition to the photographing mode, the movable blade 20 is moved by the force generated by the drive unit 19. As a result, the movable blade 20 is moved further in the opening direction than the position where the opening 15 is not completely blocked by the movable blade 20 and is fully opened.

  FIG. 32 shows the maximum state in which the opening 15 is forcibly opened by the insertion of a finger or the like, vibration, external force, etc. when the drive unit 19 is not energized. As shown, the rotor 66 is rotated in the clockwise direction in the drawing at a predetermined angle (see “+ θf” in the figure) with the support shaft 69 of the arm member 68 as the rotation center axis. The drive ring 22 is rotated in the counterclockwise direction in the figure, but the rotation angle is smaller than the rotation angle in the state shown in FIG. 30 (θf <θr).

  The magnet 67 has a neutral line nl positioned substantially perpendicular to the surfaces of the salient poles 60, 60 of the stator portion 58, and projects with reference to a direction perpendicular to the neutral line (vertical direction in the figure). The portion 74 has come to a position rotated clockwise by the angle “+ θf”.

  The state shown in FIG. 32 occurs temporarily. As will be described later, the magnetic balance of the rotor portion 66 is balanced with respect to the salient poles 60 and 60 of the stator portion 58 in the drive portion 19 when no power is supplied. The rotor part 66 rotates in the direction. That is, the magnetic part of the magnet 67 tries to face the salient poles 60, 60, and the rotor part 66 rotates in the counterclockwise direction in the figure, and accordingly, the drive ring 22 rotates in the clockwise direction, and the movable blade 20 is moved in the direction of closing the opening 15, and finally the state shown in FIG. 31 is obtained.

  FIG. 33 is a graph illustrating torque characteristics with respect to the rotation angle of the rotor portion 66. The horizontal axis indicates the rotation angle of the rotor portion when the state shown in FIG. The vertical axis indicates the magnitude (absolute value) of torque in arbitrary units. “Θc” indicates a state in which the opening 15 is closed and corresponds to an angle of “−θr−θf” (see FIG. 31), and “θo” indicates that the opening 15 is completely opened. Thus, the movable blade 20 cannot rotate any more (see FIG. 30), which corresponds to an angle of “+ θr−θf”.

  A graph line g1 indicated by a solid line in FIG. 33 shows a torque characteristic when the coils 62A and 62B are not energized, and represents a holding torque that acts as a so-called magnetic spring. As shown in the figure, it shows the minimum value (zero) when the rotation angle θ is zero, and the torque increases as the rotation angle magnitude (absolute value) increases in the positive or negative direction (rotation It shows a V-shaped characteristic that is symmetric with respect to zero angle.) In addition, as for the rotor part 66 at the time of non-energization, the area where the area where the N pole and the S pole of the magnet 67 are opposed to the salient poles 60 and 60 becomes the maximum is a magnetic stable point. Further, since the rotation of the movable blade 20 is limited to the range shown in FIG. 30 and the position shown in FIG. 31, the closed end where the rotation angle is equal to θc and the open end where the rotation angle is equal to θo. (Same as a so-called magnetic spring). This is a so-called magnetic spring in which the opposite direction is generated in the closing direction (negative direction) and the opening direction (positive direction) of the opening 15 with the reference point at which the holding torque has the lowest value as a boundary. To do.)

  In addition, a graph line g2 indicated by a one-dot chain line in the figure indicates a torque characteristic when the coils 62A and 62B are energized, and shows a maximum value when the rotation angle θ is zero as shown in FIG. The magnitude of the torque gradually decreases as the (absolute value) increases in the positive direction or the negative direction (shows a symmetrical chevron characteristic with reference to zero rotation angle).

  Incidentally, “τs” shown in the figure indicates a drive limit due to loss torque or the like.

  As indicated by the broken vertical line in the figure, the rotation range (usage range) of the rotor portion 66 is from a negative value θc to a positive value θo, but the angle range “Am” ( That is, the negative region range “θc˜0”) is wider than the angle range “Ap” in the direction in which the opening 15 is opened (that is, the positive region range “0-θo”). That is, with the rotation position of the rotor portion 66 when the holding torque is minimum on the graph line g1 as a reference position, the rotation range of the rotor portion in the closing direction related to the opening 15 is in the opening direction related to the opening. The rotation range of the rotor portion 66 is also increased. When the closed position (see FIG. 31) of the opening 15 is the first position and the open position (see FIG. 30) of the opening 15 is the second position, the first position and the second position are The opening 15 is fully opened at a third position that is in the closing direction with respect to the reference position (at the third position, the direction of the holding torque acts in the closing direction of the opening 15).

  In this way, when the user accidentally inserts a finger, vibration, external force, or the like is applied to the lens protection device 14 when no power is supplied, the movable blade 20 is moved to, for example, the third position (the holding torque is the above). Even if the opening 15 is opened by moving to a position exceeding τs, etc., the driving ring 22 rotates in a certain direction by the holding torque of the driving unit 19, and the movable blade 20 moves in a direction in which the opening 15 is always closed. Finally, the opening is fully closed. Therefore, it is possible to take lens protection measures without using a mechanical biasing means to always bias the position of the movable blade toward the first position.

  In the stator portion 58, as described above, a pair of salient poles 60, 60 are formed on the magnetic core 59 around which the coils 62A, 62B are wound, and opposing surfaces 60a, 60a of the salient poles are formed. Are parallel to each other, and the magnet 67 is positioned between the opposing surfaces in a rotatable state, the rotor portion has a salient pole due to mounting error or manufacturing error of the rotor portion 66. Even if it deviates in the direction parallel to the opposing surfaces 60a, 60a, this provides the advantage that the magnetic balance is hardly affected on the stop position of the magnet 67. That is, when the opposing surfaces of the salient poles forming a pair are formed in a concave shape corresponding to the side surface (circumferential surface) of the rotor magnet, no current is applied due to the relative displacement between the rotor portion and the salient pole portions. There is a problem of adversely affecting the angular characteristics of the holding torque at the time (the torque characteristics changing greatly). If the positional variation is large, for example, in the worst case, when the vibration or external force is applied to the apparatus when no power is supplied, the movable blade 20 is moved in the direction to open the opening 15, resulting in the opening of the opening. There is a risk that the state will remain as it is. Therefore, by making the opposing surfaces of the salient poles parallel to each other and positioning the magnet in a rotatable state with a predetermined gap between them, such a variation in the assumed position within the allowable range causes such a problem. It is possible to prevent problems from occurring.

  Further, like the stator portion 58 described above, winding the coil winding around the core portions 59a and 59b located between the salient poles 60 and 60 and the portion 59c of the magnetic core 59 saves space. It is effective for downsizing and downsizing.

  Next, control of the drive unit 19 according to the lens protection device 14 will be described with reference to FIGS.

  FIG. 34 is a schematic view illustrating the configuration of the main part of the imaging device. For convenience of illustration, the lens protection device 14 is shown as viewed from the front.

  The lens protection device 14 is provided with magnetic detection means 27 as position detection means for detecting the position of the movable blade 20. For example, the following configuration forms are mentioned.

(A) A configuration using a detection means including a detection element, an amplification unit, and an output unit, such as a Hall IC.

  First, in the above (a), the binarized signal is sent to the control unit 120 as a detection result as it is, for example, in a detection means including a Hall element, an amplification unit (such as an operational amplifier) and an output unit.

  Further, as in (b) above, in the case of a detection element (Hall element) that does not have an amplification unit, the detection output is amplified by the amplifier 121 and then sent to the control unit 120. For example, adjustment is made so that a specific detection voltage is obtained when the movable blade 20 comes to the first position or the second position. As in the example described above, in the configuration in which the magnet 67 is two-pole magnetized, the Hall element can be disposed at a predetermined position within the movable range of the rotor portion 66 so as to face the boundary of the magnetic pole.

  The control unit 120 controls the drive unit 19 according to the position detection signal of the movable blade 20. For example, a microcomputer or the like is used and includes a CPU (Central Processing Unit), a memory, a clock circuit, and the like.

  The drive control signal output from the control unit 120 is supplied to the coils 62A and 62B of the drive unit 19 via the drive circuit 122.

  Light that has entered the imaging optical system 123 in a state where the opening 15 is not blocked by the movable blade 20 is received by the imaging unit 124. The photoelectrically converted signal is sent to the signal processing unit 125.

  The signal processing unit 125 includes a camera DSP (Digital Signal Processor) unit, a circuit unit for image compression and expansion, processing such as automatic focus adjustment (AF), automatic exposure (AE), and auto white balance (AWB). The image signal is sent to a display unit 126 using a liquid crystal display device or the like, and a recording / reproduction processing unit 127.

  The recording / playback processing unit 127 processes the image information and records the information on a predetermined recording medium 128, for example, a recording medium using a semiconductor storage element, a magnetic or optical recording medium, or the like. Is provided with a circuit and an interface for reading out and reproducing data.

  FIG. 35 is a graph illustrating the angular characteristics of torque on the upper side and the sensor output using the Hall IC on the lower side in the form (a).

  In the above figure, the horizontal axis represents the rotation angle “θ” of the rotor portion 66, and the vertical axis represents torque (the direction of torque acting in the direction of moving the movable blade 20 to open the opening 15 is positive or negative). Is defined as the positive direction, and the graph line shown in the third quadrant of the figure is folded symmetrically with respect to the horizontal axis and the graph line shown in the first quadrant corresponds to the graph line g1 in FIG. A range indicated by an arrow “ls” indicates a range of loss torque corresponding to “−τs to + τs”, and θc and θo are as described above (for convenience of illustration, the magnitude of θc and θo Shows an example of the same size.)

  The neutral region indicated by “NR” in the figure occupies a predetermined range in which the magnitude of the torque is less than τs centering on the position where the torque is zero at the zero rotation angle. That is, in the neutral region where the torque is lower than the loss torque, the rotor portion 66 does not rotate when no power is supplied. On the other hand, in a region other than the neutral region, the rotor portion 66 rotates toward the closer end (open end or closed end), and the magnitude (absolute value) of torque increases toward the end. Therefore, if the size of the opening, the rotation range of the movable blade, etc. are designed so that the opening 15 is opened at a position outside the neutral region in the third quadrant of the figure, the torque in the direction to always close the opening when no power is supplied. (On the other hand, if the opening 15 is designed to be opened at a position outside the neutral region in the first quadrant in the figure, the opening is closed outside the neutral region in the first quadrant when the opening is opened to a certain extent. It will disappear.)

  The rotation position detection signal obtained by the Hall IC is composed of two signals “SS1” and “SS2” as shown in the figure below, and both are binarized signals.

  For example, as shown by a solid line in the figure, the detection signal SS1 has an H (high) level in an angle range in which the rotation angle of the rotor portion 66 shows a negative value and in an angle range that does not exceed the neutral region in the first quadrant in the upper diagram. In the first quadrant, the L (low) level is shown in an angular range exceeding the neutral region.

  The detection signal SS2 indicates the L level in the angular range where the rotation angle of the rotor portion 66 does not enter the neutral region in the third quadrant of the upper diagram, as shown by the one-dot chain line in the figure, and in the neutral region and in the first quadrant H level is shown.

  Therefore, the neutral region is detected as a range in which the detection signals SS1 and SS2 both indicate the H level.

  FIG. 36 is a graph showing the drive current to the coil according to the rotation angle on the upper side and the sensor output (SS1, SS2) of the Hall IC on the lower side.

  In the upper diagram, the horizontal axis indicates the rotation angle “θ” of the rotor portion 66, and the vertical axis indicates the drive current “Idrv” (the drive current in the direction to open the opening 15 is a positive value).

  In the figure below, the horizontal axis indicates the rotation angle “θ”, and the vertical axis indicates the output level of the Hall IC.

  Regarding the control of the drive current Idrv, the first region close to the closed end position of the opening 15, the second region close to the open end position of the opening 15, and the position between the first region and the second region. Can be divided into a third region (intermediate region). That is, the neutral region is positioned between the θc side region and the θo side region, and the magnitude of the torque is set to be equal to or less than the threshold value (τs) in the neutral region as described above. In the neutral region, the detection signals SS1 and SS2 of the Hall IC both show an H level, the detection signal SS1 shows an H level, and the detection signal SS2 shows an L level in the region on the θc side of the neutral region. Further, in the region on the θo side from the neutral region, the detection signal SS1 indicates the L level, and the detection signal SS2 indicates the H level. In this way, the three regions can be easily discriminated based on the binarized detection signal of the Hall IC.

  First, in the drive control when opening the opening 15 from the closed state, the drive unit 19 is energized when the detection signal SS1 is in the H level range, and when the SS1 becomes the L level, Stop energization. That is, when the detection signal SS1 is input to the control unit 120 and SS1 indicates the H level, the coils 62A and 62B are energized from the control unit 120 via the drive circuit 122, and a positive drive current Idrv flows (neutral). Energization is required until the area is overcome.) Thereafter, the energization of the coils 62A and 62B is cut off by a control signal sent from the control unit 120 to the drive circuit 122 when the detection signal SS1 becomes L level. At this time, the neutral region has been removed, and when the energization of the coil is stopped, the movable blade 20 moves toward the open end indicated by θo only by the torque of the magnetic spring and finally reaches the state of θo.

  Further, in the drive control in the case where the opening 15 is closed from the state where the opening 15 is opened, whether or not the drive unit 19 is energized is defined according to the level of the detection signal SS2. That is, the drive unit 19 may be energized when the detection signal SS2 is in the H level, and the energization of the drive unit 19 may be stopped when SS2 becomes the L level. When the detection signal SS2 is input to the control unit 120 and SS2 indicates an H level, the coils 62A and 62B are energized from the control unit 120 via the drive circuit 122, and a negative drive current Idrv is supplied. Thereafter, when the detection signal SS2 becomes L level, the energization of the coils 62A and 62B is cut off by a control signal sent from the control unit 120 to the drive circuit 122. At this point, the neutral region has been removed, and when energization of the coil is stopped, the movable blade 20 moves toward the closed end indicated by θc only by the torque of the magnetic spring, and finally reaches the state of θc.

  Thus, in the form in which the control unit 120 controls the energization or non-energization of the coil in accordance with the position of the blade member detected by the position detection unit, between the first position and the second position described above. It is easy to detect the intermediate area in the area and perform drive control for each of the three divided areas. The intermediate region is preferably defined as a neutral region where the holding torque of the drive unit and the load torque of the rotor unit are balanced when the coil is not energized, and the torque of the magnetic spring is within the range beyond the region. The movable blade can be moved to the open end or the closed end without power supply. In addition, when the movable blade is stopped by an unexpected force in the neutral region, it is possible to perform a restart (retry) operation by energizing the coil or to move the movable blade in the opposite direction. .

  Not only in this example, but within the range beyond the neutral region, it is also possible to limit the energization of the coil and reduce the drive current value. In any case, a power saving effect can be obtained, and the collision noise can be eliminated or reduced by cutting off the current supply to the coil before the movable blade reaches the open end or the closed end, or by restricting the current supply amount. Can do.

  Further, in the form using the Hall IC, the amplifier 121 and the A / D converter are unnecessary, and the adjustment of the position sensor is not required.

  As described above, the form (a) is advantageous in terms of cost reduction and downsizing of the protection device for the optical element by taking advantage of the simple configuration and method of drive control.

  Next, the drive control according to the mode (b) will be described according to the examples shown in FIGS.

  In this embodiment, it is necessary to amplify the analog signal output from the Hall element, and to convert the signal into a digital signal by a built-in A / D converter, and then import the signal into the control unit 120. Although the configuration is somewhat complicated in the comparison, the position of the movable blade can be detected with high accuracy.

  The detection signal of the Hall element is input to the control unit 120 after amplification and recognized as a digital signal. Then, the control unit 120 outputs a PWM (pulse width modulation) wave control signal to the drive circuit 122. Upon receiving the signal, the drive circuit 122 performs voltage and impedance conversion, and supplies the drive signal to the drive unit 19.

  FIG. 37 is a graph illustrating the relationship between the rotation angle “θ” on the horizontal axis and the drive current “Idrv” (the current when opening the opening is a positive value) on the vertical axis. A control example is shown in which the output torque including the torque of the magnetic spring is made constant in a range excluding the neutral region. Note that “Ish” and “−Ish” shown in the figure respectively indicate current thresholds corresponding to values that allow for loss torque.

  First, in the drive control in the case where the opening 15 is opened from the state in which the opening 15 is closed, the Idrv value decreases as the rotation angle θ decreases and goes to the right in the figure. That is, the Idrv value is increased in the positive direction in the vicinity of θc so as to cancel out the torque characteristic shown in the third quadrant of FIG. 35, and the Idrv value is gradually decreased in the direction approaching θo. When the θ value exceeds the vertical axis and further approaches θo, the Idrv value exhibits a negative value after crossing the θ axis, and the Idrv value changes in a straight line from the further advanced position to θo. That is, as it approaches θo, the absolute value of Idrv increases in the negative direction with a predetermined slope.

  Except for the region near Ish, a PWM wave signal is output from the control unit 120 to the drive circuit 122 so that the sum of the torque generated by the magnetic spring and the torque generated by the drive unit when energized is substantially constant.

  In the drive control in the case where the opening 15 is closed after the opening 15 is opened, the Idrv value increases as the rotation angle θ decreases and goes to the left in the figure. That is, the absolute value of Idrv is increased in the negative direction in the vicinity of θo so as to cancel out the torque characteristics shown in the first quadrant of FIG. 35, and the absolute value of Idrv is gradually decreased as the direction approaches θc. When the θ value exceeds the vertical axis and further approaches θc, the Idrv value shows a positive value after crossing the θ axis, and the torque changes in a straight line from the further advanced position to θc. That is, as it approaches θc, the Idrv value increases in the positive direction with a predetermined slope.

  Except for the region near Ish, a PWM wave signal is output from the control unit 120 to the drive circuit 122 so that the sum of the torque generated by the magnetic spring and the torque generated by the drive unit when energized is substantially constant.

  Since the loss torque (load) does not change depending on the position of the movable blade within the movable range, the movable blade can be driven with an appropriate torque over the entire movable range by making the output torque including the magnetic spring constant.

  In this example, Idrv is controlled so as to have a substantially constant inclination as it approaches θo and θc. This is because the operation sound is reduced by minimizing the force of collision at the end of the movable range (mechanical end). This is because the durability is improved at the same time. That is, if there is almost no sound during the movement of the blade member during the movable stroke and the operation sound can be eliminated at the time of collision with the member at the end, silence of the barrier device can be realized. Therefore, in order to minimize this operating noise by open loop control, driving with a current waveform as shown in FIG. 37 is preferable. In addition, regarding the limit of the number of times of endurance, deterioration of the barrier mechanism due to collision with the end of the movable range is a problem. Generally, if the number of times of endurance is increased by a mechanism, the barrier itself becomes large, and if the movable part becomes large, consumption Electricity will increase. Therefore, by adopting the drive control according to the current waveform shown in FIG. 37, it is possible to realize a low power consumption barrier mechanism without increasing the movable part. Note that it is necessary to determine an optimum value for the amount of current that flows in the opposite direction to the operation direction in consideration of the above matters.

  FIG. 38 is a graph showing another control example, and the definition of each axis is the same as FIG.

  Differences from the above example are as follows.

In the range close to the closed end of the movable blade, the amount of change in drive current gradually decreases as it approaches θc.
-In the range close to the open end of the movable blade, the amount of change in drive current gradually decreases as it approaches θo.

  In this example, in the region close to the open end or the closed end, the sum of the torque of the magnetic spring and the torque generated by the drive unit 19 by energization is controlled to be smaller than the specified value, and the end of the movable range By reducing the collision speed at the (mechanical end), it is possible to reduce the collision sound and improve the durability.

  FIG. 39 is a graph showing still another control example, and the definition of each axis is the same as FIG.

  The difference from the example shown in FIG. 38 is as follows.

・ When the rotation angle θ changes in the direction in which the opening is opened by the movement of the movable blade, Idrv becomes less than Ish, and the coil is energized when “θ = θp (> 0)” and the Idrv value is zero. To be stopped.
When the rotation angle θ changes in the direction in which the opening is closed by the movement of the movable blade, the coil is energized when Idrv exceeds −Ish and “θ = θq (<0)” and the Idrv value is zero. Will be stopped.

  In this example, the range indicated by θq to θp corresponds to the neutral region described above, and the drive unit 19 is generated by the torque of the magnetic spring and energization between the open end or closed end of the movable blade and the neutral region. Control is performed so that the sum of the torque and the torque is constant. That is, as described above, the Idrv value decreases as the rotation angle θ decreases. However, when going to the other end beyond θp or θq, when the neutral region is passed, The output of the drive circuit 122 is stopped. That is, after that, the movable blade is moved toward the other end only by the torque of the magnetic spring, that is, toward the open end indicated by θo when opening the opening and toward the closing end indicated by θc when closing the opening. Move. Thus, the movable blade can be driven with the minimum necessary power consumption.

  The application of the present invention is not limited to the above-described example. For example, in the neutral region, the energization time of the coil is limited so as not to exceed a predetermined time, or the time limit related to the energization time is not limited. Immediately before the end, a more precise drive control can be realized by flowing a drive current in a direction opposite to the current energization direction and controlling the energization time.

  For example, when setting the time limit to determine that the energization time of the coil is long, abnormal and harmful, avoid the failure of the barrier mechanism due to the insertion of foreign matter, etc., and do not pinch fingers Should be considered. In other words, if the energization time becomes longer due to foreign matter insertion or the like, the performance may deteriorate due to the temperature rise. Therefore, it is necessary to limit the time in order to cut off the continuation of such a situation. It is determined from the ascending characteristics and heat resistance. In addition, with regard to finger insertion, it is necessary to apply a time limit to prevent injury, and the time limit is determined from the torque (drive current) generated in the actuator of the barrier mechanism.

  If it is determined that the cause of the coil energizing time exceeding the time limit is foreign object insertion, for example, energizing in the opposite direction and then energizing in the original direction again, It may be possible to recover by shaking off foreign objects. The energizing time and energizing amount for that purpose can be determined from the torque generated by the actuator of the barrier mechanism, the assumed foreign matter, and the assumed insertion location. In the case of foreign matter insertion, unlike in the case of finger insertion, it stops in the locked state, so if the position of the barrier blade during the energization time does not change at all, it can be easily determined that the foreign matter has been caught. .

  Next, the flow of processing related to the drive control of the movable blade will be described with reference to the flowcharts shown in FIGS.

  FIG. 40 shows a processing example when the movable blade is moved to open the opening from a state where the opening is closed.

  First, in step S1, the drive current Idrv is supplied to the coils 62A and 62B by energization of the drive unit 19. In step S2, it is determined whether or not the opening 15 is opened. When the opening 15 is opened, the process proceeds to step S3, and energization of the drive unit 19 is stopped. In the example illustrated in FIG. 36, whether or not the coil is energized is determined based on the detection signal of the Hall IC. In the example illustrated in FIG. 39, the rotation angle θ exceeds the range indicated by θq to θp. In step S2, it is determined whether or not the rotation angle θ exceeds the neutral region and the opening has been opened to some extent.

  If it is determined in step S2 that the opening 15 is not fully open, the process proceeds to step S4, where a counting process based on a predetermined clock signal is performed. Then, in the next step S5, a condition determination is made as to whether or not the count value of the counter is equal to or smaller than a predetermined value, and if a positive determination result is obtained, the process returns to step S1. However, when a negative determination result is obtained (that is, when the movable blade does not reach the open end position indefinitely), the process proceeds to step S6, where the drive unit 19 is urgently stopped and the coils 62A and 62B are Turn off the power.

  FIG. 41 shows a processing example when the movable blade is moved from a state where the opening is opened to close the opening.

  In step S11, the drive current Idrv is supplied to the coils 62A and 62B by energization of the drive unit 19. In step S12, it is determined whether or not the opening 15 is closed. When the opening 15 is closed, the process proceeds to step S13 to stop energization of the drive unit 19. In the example illustrated in FIG. 36, whether or not the coil is energized is determined based on the detection signal of the Hall IC. In the example illustrated in FIG. 39, the rotation angle θ exceeds the range indicated by θq to θp. In step S12, it is determined whether or not the rotation angle θ exceeds the neutral region and the opening is closed to some extent.

  If it is determined in step S12 that the opening 15 is not closed, the process proceeds to step S14 and a counting process is performed. In the next step S15, a condition determination is made as to whether or not the count value of the counter is equal to or less than a predetermined specified value. If a positive determination result is obtained, the process returns to step S11. However, if a negative determination result is obtained (that is, if the movable blade has not reached the closed end position indefinitely), the process proceeds to step S16 to clear (reset) the count value and then perform the retry operation. Therefore, the process proceeds to step S1 in FIG.

  When the movable blade does not reach the closed end in the closing operation of the opening 15, it is desirable for safety measures to end the drive control with the opening being opened so that fingers and the like are not sandwiched between the opening and the movable blade. (Forcibly continuing the closing operation may cause fingers or foreign objects to come off or cause damage.) Further, ending the drive control with the opening opened is also effective in reducing the probability of losing the photographing opportunity.

  According to the configuration described above, the following advantages can be obtained.

-Realization of a protective device with excellent reliability and durability For example, when a direct drive type actuator is used to drive a movable blade, a sensor that detects only the position of the open end and the closed end of the movable blade The torque generated by the actuator is set so that the movable blade can be sufficiently driven even in a region close to the open end or the closed end or even at the maximum load position in the movable range. In that case, when position detection is performed by a mechanical switch, loss torque is generated by the switch, and position detection accuracy is low. For this reason, in order to be able to sufficiently guarantee the operation even in the region close to the open end or the closed end, it is necessary to generate a large torque. It is necessary to consider durability. On the other hand, according to the above configuration, magnetic detection means such as a Hall element is used, and it is not necessary to pass a large current through the coil when the drive unit is energized, and is close to the open end or the closed end. In the region, the movable blade can be moved toward the open end or the closed end using the torque of the magnetic spring (a mechanical biasing spring or the like is basically unnecessary).

A protection device with low power consumption and high silent performance can be realized.For example, in a region closer to the closed end position or open end position of the movable blade than the intermediate region detected by the position detection unit, the control unit Thus, the energization of the coil is stopped or the energization amount is limited. In other words, the power consumption during driving can be reduced by moving the movable blades and cutting off the energization or reducing the energization amount when it passes over the area (in the application to portable devices etc. Drive time can be extended.) Further, it is possible to eliminate or sufficiently reduce the sound (impact sound) generated by the impact when the blade member constituting the movable blade comes to the closed end position or the open end position. In the non-energized state of the drive unit, the movable blade is moved by the torque of the magnetic spring in the direction toward the end (open end or closed end) closer to the current position, except for the neutral region. Becomes larger. Therefore, even if the energization is stopped when the neutral region is exceeded, the blade member constituting the movable blade is moved to the closed end position or the open end position, and at that time, the blade member is moved within the movable range with an excessive torque. Since it does not collide with a terminal part (stopper part etc.) vigorously, it is effective as a measure against operating noise.

・ Effective for miniaturization and cost reduction of lens barrier devices, etc. No mechanical means for constantly urging the movable blade in the closed end direction is required, the structure is simple, and a large current is supplied to the drive unit. It is effective to reduce the size of the drive unit because it is sufficient to generate the minimum necessary torque with allowance for loss torque.

It is a figure which shows the basic structural example of the protection apparatus of the optical element which concerns on this invention. It is a perspective view showing an example of composition of an imaging device concerning the present invention. It is a figure which shows the structural example of the protection apparatus which concerns on this invention with FIG. 4 thru | or FIG. 29, and this figure is a perspective view. It is a front view of a protection device. It is a rear view of a protection device. It is a disassembled perspective view at the time of seeing a protection device from diagonally forward with the photographing direction as the front side. It is a disassembled perspective view at the time of seeing a protection apparatus from diagonally backward. It is the front view which illustrated the 1st component member. It is the perspective view which looked at the 1st component member from diagonally back. It is a figure which shows the example of a shape of the blade | wing member which comprises a movable blade | wing with FIG. 11 thru | or FIG. 13, and this figure is a front view. It is a rear view of a blade member. It is a side view of a blade member. It is sectional drawing of a blade member. It is a figure which shows the state by which the opening was closed in the state in which the blade | wing member was attached to the 1st structural member. It is a figure which shows the state by which opening was opened in the state in which the blade | wing member was attached to the 1st structural member. It is a figure which shows the structural example of a drive part with FIG. 17 thru | or FIG. 20, and this figure is a side view of a stator part. It is a bottom view of a stator part. It is a figure which shows the structural example of a rotor part with FIG. 19, and this figure is a perspective view. It is a side view of a rotor part. It is a figure which shows the structure of a drive part. It is the figure which illustrated the 2nd component member with Drawing 22 thru / or 24, and this figure is a front view. It is a rear view. FIG. It is a perspective view. 26 and 27 together with the drive ring, this figure is a front view. It is a rear view. It is the disassembled perspective view which showed the state which removed the magnet for position detection. It is the perspective view which illustrated the 3rd component member. It is a rear view which shows a 3rd structural member. FIG. 31 is a view for explaining an operation related to the movement of the movable blade together with FIGS. 31 and 32, and is a view showing a state where the blade members are rotated to the most distant positions and the opening is completely opened. It is a figure which shows the state which was rotated to the position where blade members contact | abutted and the opening was completely obstruct | occluded. It is a figure which shows the maximum state to which the opening was forcibly opened at the time of no electricity supply. It is the graph which illustrated the torque characteristic with respect to the rotation angle of a rotor part. It is explanatory drawing which showed roughly about the principal part structure of the imaging device. It is the graph which showed the rotation angle characteristic of the torque above, and showed the sensor output below. It is a graph for demonstrating an example of the control form which used Hall IC for the position detection means. It is a graph for demonstrating an example of the control form which used the Hall element for the position detection means. It is a graph for demonstrating another example of a control form. It is a graph for demonstrating another example of a control form. It is a figure for demonstrating the flow of the process which concerns on drive control of a movable blade with FIG. 41, and this figure shows the process example in the case of moving a movable blade from the state in which the opening was closed, and opening this opening. It is a flowchart figure. It is a flowchart figure which shows the process example in the case of moving a movable blade | wing from the state in which the opening was opened, and closing this opening.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Protection apparatus, 5 ... Opening, 7 ... Movable blade, 9 ... Position detection means, 10 ... Control means, 11 ... Imaging device, 15 ... Opening, 19 ... Drive part, 20 ... Movable blade, 58 ... Stator part, 59 ... Magnetic core, 59a ... First part, 59b ... Second part, 59c ... Third part, 60 ... Salient pole, 60a ... Opposing surface, 62A, 62B ... Coil, 66 ... Rotor part, 67 ... Magnet

Claims (5)

A driving unit having a stator unit including a coil and a magnetic core, and a rotor unit including a magnet; and a closing direction in which the opening is closed by the driving unit in order to close or open the opening facing the optical element; With movable blades that move in the opening direction to open the opening,
When the coil is energized, the movable blade moves further in the opening direction than the first position where the opening is closed by the movable blade and the position where the opening is not fully blocked by the movable blade. A protection device for an optical element configured such that the movable blade is moved by the driving unit over the second position,
When the coil is not energized, the movable blade is moved in the direction to close the opening by the holding torque of the driving unit, and the rotation position of the rotor unit when the holding torque is minimized is used as a reference position. The rotation range of the rotor part in the closing direction is made larger than the rotation range of the rotor part in the opening direction, and is between the first position and the second position. The opening is fully opened at the third position in the closing direction from the reference position ,
A plurality of salient poles are formed on the magnetic core around which the coil is wound, and opposing surfaces of the salient poles are parallel to each other, and the magnet is rotatable between the opposing surfaces. Is located at
In the magnetic core, a first part and a second part in which salient poles are respectively formed, and a third part connecting them are integrally formed,
The coil wound around the first part and the coil wound around the second part are connected in series with each other, and the winding direction of each coil is opposite,
Position detecting means for detecting the position of the movable blade moved between the first position and the second position, and the drive unit is controlled according to a detection signal from the position detecting means. Control means for,
An optical element protection device that controls the energization or non-energization state of the coil or limits the energization amount according to the position of the movable blade detected by the position detection means . In the protection device of the optical element according to claim 1 ,
An optical element protection device, wherein the position detection means detects an intermediate region between the first position and the second position. In the protection device of the optical element according to claim 2 ,
The intermediate region detected by the position detecting means is defined as a neutral region where the holding torque of the drive unit and the load torque of the rotor unit are balanced when the coil is not energized. Optical element protection device. In the protection device of the optical element according to claim 2 ,
When the movable blade is further moved to the first position or the second position beyond the intermediate region detected by the position detecting means, the energization of the coil is stopped by the control means. Or a protective device for an optical element, characterized in that the amount of energization is limited. A drive unit having a stator unit including a coil and a magnetic core, and a rotor unit including a magnet, and a blockade that closes the opening by the driving force of the drive unit to close or open the opening facing the optical element. A movable vane that is moved in a direction or an opening direction that opens the opening,
When the coil is energized, the movable blade moves further in the opening direction than the first position where the opening is closed by the movable blade and the position where the opening is not fully blocked by the movable blade. An imaging apparatus including a barrier mechanism configured such that the movable blade is moved by the driving unit over the second position,
When the coil is not energized, the movable blade is moved in the direction to close the opening by the holding torque of the driving unit, and the rotation position of the rotor unit when the holding torque is minimized is used as a reference position. The rotation range of the rotor part in the closing direction is made larger than the rotation range of the rotor part in the opening direction, and is between the first position and the second position. The opening is fully opened at the third position in the closing direction from the reference position ,
A plurality of salient poles are formed on the magnetic core around which the coil is wound, and opposing surfaces of the salient poles are parallel to each other, and the magnet is rotatable between the opposing surfaces. Is located at
In the magnetic core, a first part and a second part in which salient poles are respectively formed, and a third part connecting them are integrally formed,
The coil wound around the first part and the coil wound around the second part are connected in series with each other, and the winding direction of each coil is opposite,
Position detecting means for detecting the position of the movable blade moved between the first position and the second position, and the drive unit is controlled according to a detection signal from the position detecting means. Control means for,
An imaging apparatus characterized by controlling the energization or non-energization state of the coil or limiting the energization amount according to the position of the movable blade detected by the position detection means .

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