KR101141213B1 - Diaphragm device - Google Patents

Abstract

The present invention provides a diaphragm device capable of realizing compactization of a drive system arrangement including a stepping motor while inserting a gear reduction mechanism between a stepping motor and a rotary lever for driving the diaphragm blade.

In the diaphragm apparatus which adjusts a diaphragm by reciprocally sliding two diaphragm vanes 12 and 13 on a diaphragm board | substrate 10, the rotation lever 40 rotationally driven by the stepping motor 110, and a rotation lever And a pair of drive pins 44a and 44b which are formed to protrude on each other and are slid to the long holes 13d and 12d formed in the respective aperture blades to drive the aperture blades, and between the rotary lever and the rotating shaft of the stepping motor. The reduction gear mechanism 70 is inserted, and the reduction gear mechanism is formed integrally with the pinion 112 attached to the rotating shaft of the stepping motor and the rotation lever, and indirectly through the pinion or the intermediate gear 60. It is composed of the inner tooth gear 40 to be mated.

Description

Aperture Device {DIAPHRAGM DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to diaphragm devices for optical devices such as video cameras, still cameras, surveillance cameras, and the like.

In this type of aperture device, two aperture blades are provided so as to slide linearly on a diaphragm substrate having an opening for forming an optical path. The optical path is controlled to be iris-slided by reciprocating slides in opposite directions with a driving pin formed so as to protrude to the rotary lever. In addition, Patent Document 1 discloses that a stepping motor is mounted as a driving source for rotating a rotating lever, and a gear reduction mechanism is inserted between the stepping motor and the rotating lever. It is disclosed by patent document 2.

When the gear reduction mechanism is inserted between the stepping motor and the rotary lever, the resolution of the diaphragm blade can be made larger than the resolution of the stepping motor. In the technique of Patent Document 2, a combination of a screw shaft and an arc gear is disclosed as a gear reduction mechanism.

Patent Document 1: Japanese Patent No. 4068684

Patent Document 2: Japanese Patent Application Laid-Open No. 8-328080

However, when the gear reduction mechanism is inserted between the stepping motor and the rotary lever, the resolution of the diaphragm blade can be made larger than the resolution of the stepping motor, so that the aperture control can be made highly accurate. When the gear reduction mechanism is composed of a screw shaft and a circular gear, as in the case of the technique, the space for attaching the drive system including the stepping motor is increased due to the arrangement of the gear mechanism. There is a problem that one batch cannot be realized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an aperture device capable of realizing a compact arrangement of a drive system including a stepping motor while inserting a gear reduction mechanism between a stepping motor and a rotary lever for driving the aperture blade. It is done.

In the invention according to claim 1, the diaphragm is formed on a diaphragm substrate having an opening for forming an optical path, and is formed so as to slide linearly on the diaphragm and is reversed from each other. Reciprocating slide drive with a reciprocating slide to iris slide two iris blades to iris the optical path, and a direction in which its axis of rotation is orthogonal to the iris substrate to drive the iris blades. A rotation lever attached to the aperture substrate so as to rotate at a position; and protrude at a position spaced apart from the rotation axis on the rotation lever, each of which is formed at each of the aperture blades and the aperture blades. Sliding in a long slot in a direction orthogonal to the slide direction of the A pair of drive pins coupled to each other so as to slide the aperture blades in the opposite direction to each other by rotating the rotary lever, and its own rotary shaft to rotate the rotary lever. A stepping motor attached to the diaphragm substrate in a direction orthogonal to the diaphragm substrate, and a reduction gear mechanism inserted between the rotary lever and the rotary shaft of the stepping motor. The gear mechanism is formed with a pinion attached to the rotating shaft of the stepping motor and the rotary lever integrally and indirectly engaged with the pinion directly or indirectly through an intermediate gear. It is characterized by consisting of a tooth gear (inner tooth gear).

The invention according to claim 2 is the diaphragm device according to claim 1, wherein a diaphragm blade driving mechanism attachment portion is formed on the diaphragm substrate, and a support shaft for a rotary lever is formed to protrude onto the diaphragm blade driving mechanism attachment portion. The inner lever gear (rotation lever) is supported so as to rotate, while the inner cover gear (motor 구동 着 cover) to cover the rotation lever attached to the inner gear gear on the top of the iris blade drive mechanism attachment portion ) Is assembled, and the stepping motor is attached to the outside of the motor attachment cover, and a pinion attached to the rotating shaft of the stepping motor is connected to the inside of the motor attachment cover through an opening formed in the motor attachment cover. The pinion is inserted into the inner tooth gear inside the motor attachment cover. That it is directly or indirectly through an intermediate gear occlusion and characterized.

The invention according to claim 3 is the diaphragm device according to claim 2, wherein the reduction gear mechanism comprises an intermediate gear inserted between the pinion, the inner tooth gear, and the pinion and the inner tooth gear. And a small gear that is engaged with the pinion and a small gear that is engaged with the inner tooth gear on the same axis, and is provided with the diaphragm wing mechanism attachment portion. An intermediate gear support shaft adjacent to the support shaft for the rotation lever and penetrating the rotation lever through a cutting portion on the rotation lever formed inside the gear gear. ) Is formed to protrude, and the intermediate gear is supported on the intermediate gear support shaft so as to rotate.

The invention of claim 4 is the diaphragm device according to any one of claims 1 to 3, wherein the inner lever gear and the pinion are rotated by rotationally pressing the rotating lever with the inner gear in one direction. The non-backlash mechanism which absorbs the backlash of the backlash is provided, The said non-backlash mechanism is a fixed side of the said rotation lever side and the said aperture board | substrate, a motor attachment cover, etc. ( It is composed of a magnet and a magnetic member which are respectively installed on one side and the other and exert a magnetic force on each other and pressurize the rotary lever by the magnetic force. The rotation lever presses the rotary lever by means of at least a small diaphragm side with a small diaphragm opening. And it characterized in that it is set in rotation regions (回轉 領域) of the rotary lever.

The invention of claim 5 is the aperture device according to any one of claims 1 to 4, wherein the pair of drive pins are arranged at positions of rotation center and point symmetry of the rotary lever, When the pair of drive pins are on a straight line orthogonal to the slide direction of the diaphragm blade, the straight line is used as a reference line, and the diaphragm is opened on one side with the reference line interposed therebetween. When the small diaphragm side and the other side to be made smaller are the diaphragm side which enlarges the diaphragm aperture, the rotation area of the drive pin is the rotation angle range from the reference line at the small diaphragm side. Is biased away from the reference line so that it is larger than the rotation angle range from the reference line on the non-contrast side. That has been characterized.

According to the invention of claim 1, fine and subtle aperture control can be made simply because the aperture blade is driven by the stepping motor. In addition, since the reduction gear mechanism is inserted between the rotating shaft of the stepping motor and the rotating lever for driving the diaphragm blade, the diaphragm can be finely adjusted with a resolution greater than the step division number of the stepping motor. . In addition, since the reduction mechanism is geared instead of frictional, it does not cause a difference in the rotational positional relationship between the stepping motor and the rotary lever even when an impact is applied.衝擊 性 性 and high reliability (高 信賴 性) can be exhibited.

In addition, since the reduction gear mechanism is composed of a pinion attached to the rotating shaft of the stepping motor and an inner tooth gear integrally formed on the rotating lever and directly or indirectly engaged with the pinion, the stepping motor is moved to the rotation center position of the rotating lever. You can place them as biased as possible. Therefore, although the reduction gear mechanism is inserted between the stepping motor and the rotary lever, the compactness of the drive system arrangement can be realized.

In addition, when the reduction gear mechanism consists of an outer tooth gear and a pinion, a stepping motor is arrange | positioned in the position away from the rotation center of a rotary lever. Alternatively, the intermediate gear protrudes outward from the rotation center of the rotary lever even if the stepping motor is placed inside (as close to the center of rotation of the rotary lever) as possible by inserting an intermediate gear between the outer gear and the pinion. Becomes Therefore, the dimensions of the drive system tend to be large, making it difficult to realize a compact arrangement. This also makes it easier to interfere with other components, making it difficult to design to avoid them. In this regard, the present invention enables the implementation of a compact arrangement while increasing the degree of freedom in design by using the inner tooth gear.

In addition, by forming the driving pin at the end face of the ring in which the inner tooth gear is formed or at a position close to the ring, the radius of rotation of the driving pin can be increased while increasing the supporting rigidity of the driving pin. The slide stroke of the iris blade can be increased.

According to the invention of claim 2, the diaphragm drive mechanism (reduction gear mechanism, motor, etc.) can be easily assembled on the diaphragm substrate. In other words, first, the rotary lever with the inner tooth gear is attached to the support shaft for the rotary lever of the diaphragm blade drive mechanism attaching part, and then the motor attachment cover is assembled on the diaphragm blade drive mechanism attachment part. Thereafter, the pinion is inserted from the opening formed in the motor attachment cover to attach the stepping motor to the motor attachment cover while directly or indirectly engaging the inner tooth gear. By the above, assembly can be completed simply.

According to the invention of claim 3, since the intermediate gear can be inserted between the pinion on the stepping motor side and the inner gear gear on the rotating lever side, the reduction ratio can be increased. It can be transferred to the rotary lever. Therefore, even if the stepping number of the stepping motor is set not to be subdivided, the position of the aperture blade can be finely controlled and the aperture adjustment with high precision can be performed.

In addition, since the support shaft for the intermediate gear is formed on the diaphragm substrate, the intermediate gear can be assembled together with the rotary lever with the inner tooth gear on the diaphragm substrate, and the motor attachment cover can be assembled thereon. It can be done.

That is, although it is difficult to form the support shaft for the intermediate gear on the diaphragm substrate, the intermediate gear support shaft is formed on the diaphragm substrate by forming a cut portion in the rotary lever with the inner tooth gear and penetrating the cut portion. It is attached to the diaphragm substrate side first. In this way, assembling performance can be improved compared with the case where the intermediate gear is attached to the motor attachment cover side.

According to the invention of claim 4, since the backlash from the pinion to the inner tooth gear can be absorbed at least in the small aperture side area by the non-backlash mechanism, high-precision aperture adjustment is possible in the required area. In addition, since magnets and magnetic members are employed as the elements constituting the non-backlash mechanism, high precision control can be achieved by adding a very simple configuration. For example, as a non-backlash mechanism, it is also conceivable to pressurize the rotary lever with the inner tooth gear by a spring, but there is a drawback that the attachment of the spring becomes complicated. In this regard, in the case of the present invention, the combination of the magnet and the magnetic member is employed because the pressure of the rotary lever with the inner tooth gear is sufficient in terms of performance only in the region of the small aperture side. Sufficient performance is obtained.

According to the invention of claim 5, even if the resolution of the stepping motor (corresponding to the rotation angle of the driving pin per step of the stepping motor) is the same, the diaphragm opening on the small aperture side can be finely controlled. That is, when the rotation radius of the driving pin is r and the rotation angle of the driving pin from the reference line is θ (where θ <90 °), the movement stroke of the iris blade by the driving pin from the reference line (S) ) Becomes "S = r? Sinθ".

As can be seen from the equation &quot; S = r? Sinθ &quot;, the change amount ΔS of the moving stroke of the diaphragm blade with respect to the unit change amount Δθ of θ becomes smaller as θ becomes larger. Since the value of Δθ is the angle of rotation of the drive pin per step of the stepping motor, driving the iris blade in a region having a large θ value can finely position the iris blade. In order to realize this, the present invention sets the rotation area of the drive pin to be biased from the reference line so that the rotation angle range from the reference line on the small aperture side is larger than the rotation angle range from the reference line on the non-aqueous opening side, and this setting method is used. It is possible to easily achieve high precision of the iris control in the required area (small aperture area) simply by doing so.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1-14 is explanatory drawing of the aperture device which is 1st Example in this invention. Fig. 1 is an exploded perspective view showing the overall configuration of the diaphragm apparatus, Fig. 2 is a perspective view showing the configuration of the diaphragm substrate which is the main component of the diaphragm apparatus in the first embodiment, and Fig. 3 is a rotary lever which is the main component of the diaphragm apparatus. 4 is a perspective view illustrating a state in which a rotary lever is attached to an aperture blade driving mechanism attaching part on an aperture substrate, and FIG. 5 is a state in which an intermediate gear is attached to an upper side of the rotary lever in FIG. Fig. 6 is a perspective view showing a state where the motor attachment cover is attached on the diaphragm wing drive attachment portion in Fig. 5, and Fig. 7 shows a state where the stepping motor is attached on the motor attachment cover in Fig. 6. It is a perspective view showing.

FIG. 8 is a perspective view showing the configuration of only the drive system elements of the diaphragm blades, FIG. 9 is a plan view of the drive system of the diaphragm blades from the diaphragm wing side, and FIG. 10 is a view of the rotary lever when the diaphragm is fully opened (maximum aperture). Fig. 11 is a plan view showing the relationship between the rotational position and the iris blade, and Fig. 11 is a plan view showing the relationship between the rotational position of the rotary lever and the aperture blades when the iris is fully closed (minimum aperture), and Fig. 12 is the position of the drive pin of the rotary lever. Fig. 13 is a diagram showing the relationship between the rotation angle range of the rotation lever, and Fig. 13 is a view showing the difference between the rotation range of the rotation lever in this embodiment and the rotation angle range of the rotation lever in the comparative example, and Fig. 14 Difference between the two parts in the small opening and the control opening relative to the reference line of the rotation angle range of the rotating lever Are views for explaining the advantages of.

As shown in Fig. 1, the diaphragm device includes a diaphragm base 10 having a substantially rectangular plank shape made of a resin molded product, and one side of the diaphragm device 10. A pair of film-shaped diaphragm wings 12 and 13 assembled so as to linearly slide in a state where they are superimposed on a plate surface of a single plate, and these two diaphragm wings ( A diaphragm-shaped optical filter 15 disposed so as to be slidably slideable between the 12 and 13, and the diaphragm vanes 12 and 13 on one plate surface of the diaphragm substrate 10. And the wing cover 14 covered with the aperture blades 12 and 13 on the aperture substrate 10 after the optical filter 15 is assembled, and the other surface of the aperture substrate 10. Iris wing driver assembled on the side Comprises a (HA) and an optical filter drive mechanism (光學 filter 驅動 機構) (HB).

In the longitudinal direction of the diaphragm substrate 10 and the wing cover 14, the light path (the light axis which made the vertical axis | shaft the optical axis in FIG. Openings 11 and 14a for forming the openings are formed, and the diaphragm wing driving mechanism attaching portion 20 is formed at the position of the other end side of the diaphragm substrate 10. An optical filter drive mechanism attachment portion 30 is formed to protrude from the side of the aperture substrate 10 adjacent to the aperture wing drive attachment portion 20.

On the other hand, in the stop blades 12 and 13, the through-holes 12e and 13e of the cut | disconnected shape or a hole shape for forming a diaphragm opening are formed. Then, on the diaphragm substrate 10, the diaphragm wings 12 and 13 are reciprocated in a direction opposite to each other in the directions of the arrows f1 and f2 so as to reciprocate the edges of the transmission holes 12e and 13e. It is possible to adjust the optical path by the aperture.

The diaphragm blade drive mechanism HA assembled to the diaphragm blade drive mechanism attachment part 20 is a diaphragm blade | wing through a pair of drive pins 44a and 44b formed in the rotation lever 40. As shown in FIG. It slides 12 and 13, and is comprised centering around the stepping motor 110 and the gear reduction mechanism 70. As shown in FIG. In this case, the gear reduction mechanism 70 includes a pinion 112 attached to the rotating shaft 111 (see Fig. 8) of the stepping motor 110, and an intermediate gear 60. ) And a rotary lever 40 (strictly an inner tooth gear 43) to which an inner tooth gear (inner tooth gear) to be described later is attached.

In addition, the optical filter 15 has a transmission characteristic according to a wavelength, and in this case, an infrared ray that blocks light in an infrared ray region (including a near infrared ray region). A cut filter is used. The optical filter drive mechanism HB assembled to the optical filter drive mechanism attachment portion 30 on the diaphragm substrate 10 rotates the optical filter 15 through the driving lever 121 to rotate the optical filter ( 15) is inserted into or removed from the optical path, and is configured around an actuator 120 for two-position control. The actuator 120 is supported by the bottom plate 31 (see FIG. 2) of the optical filter drive mechanism attaching part 30 and a standing circumferential wall 32 formed to stand around it.

In this case, the optical filter 15 is formed into a thin film, and is inserted into a small gap between two aperture blades 12 and 13, and can slide along the aperture blades 12 and 13. It is formed to be. In this way, the optical filter 15 is inserted between the two aperture blades 12 and 13 so that the surface of the aperture blades 12 and 13 can be slid smoothly to form a thin film shape and stable insertion. The removal operation is possible.

The optical filter 15 has a support shaft 10a formed so as to project the transmission hole 15b formed in the bent portion of the crank lever portion 15a to the side edge portion of the diaphragm substrate 10. It is supported so that rotation is possible along the surface of the aperture blades 12 and 13 centering on this support shaft 10a. In addition, a driving pin 122 formed to protrude from the driving lever 121 is coupled to a long hole 15c formed at the front end side of the crank lever portion 15a to drive the actuator 120. By rotating the drive pin 122, the optical filter 15 is rotated about the support shaft 10a, thereby inserting or removing the optical filter 15 onto the optical path (the optical filter 15 is removed from the optical path). Can be inserted into or removed from the bed).

In Fig. 1, a plurality of guide pins, which are not shown in the drawing, are formed near the edges of the lower surface of the diaphragm substrate 10 to guide the movement of the diaphragm wings 12 and 13. Further, longitudinal grooves 12a, 12b, 12c, 13a, 13b, and 13c are formed in the vicinity of the edges of the iris blades 12 and 13 in parallel with the respective edges. By inserting the longitudinal grooves 12a, 12b, 12c, 13a, 13b, and 13c into the guide pins, the aperture blades 12 and 13 are arrows f1 and f2 on the plate surface of the aperture substrate 10. It is supported to slide in a straight line.

As an element for driving the diaphragm blades 12 and 13, first, in the diaphragm blades 12 and 13, in the direction orthogonal to the slide direction of the diaphragm blades 12 and 13, respectively, in the longitudinal end portion, Long holes (also called horizontal grooves) 12d and 13d are formed. These long holes 12d and 13d are portions to which the driving pins 44a and 44b of the rotary lever 40 slide. In addition, the diaphragm blade drive mechanism attaching portion 20 includes a rotary lever 40 and an intermediate gear 60, a motor cover cover 80, and a stepping motor 110.

As shown in Fig. 2, the diaphragm wing drive attachment portion 20 includes an approximately rectangular bottom plate 21 and an upstanding circumferential wall 22 that surrounds the bottom plate 21. (22) For fixing the positioning pin 23 and the motor mounting cover 80 to determine the position of the motor mounting cover 80 at a position close to the four corners of the upper surface. Lock pawls 24 are formed by placing the same kind of objects at diagonal positions.

Also, in Fig. 2, a support shaft 25 for a rotary lever is formed upright at the center of the upper surface of the bottom plate 21, and a support shaft for an intermediate gear is formed in the vicinity thereof. 26) is formed upright. In addition, on the bottom plate 21 around the support shaft 25 for the rotation lever, a stopper protrusion 27 for limiting the rotation range of the rotation lever 40 and the driving pins 44a, A pair of arc-shaped cut portions 28 through which 44b penetrates to the opposite side of the bottom plate 21, and a hook to prevent the fall of the rotary lever 40 ( 48) (29 and 9) are formed with cutouts 29 for engaging.

As shown in Fig. 3, the rotary lever 40 includes an inner tooth gear 43 in a part of the inner circumference, and a ring 41 in which a part of the circumferential direction is cut off. A lever bottom plate 42 which is integral with the inner bottom portion of the ring 41 and has a central hole 45 in the center thereof coinciding with the center of the inner tooth gear 43; To the edge portions 41c and 41d which protrude convexly in two places of the outer peripheral part, and to one end surface (lower surface in FIG. 3) of these edge portions 41c and 41d. A pair of drive pins 44a and 44b formed to protrude is provided. The pair of drive pins 44a and 44b are separated from the center of the center hole 45 (the rotation axis of the rotation lever), and are point symmetrical with the center of the center hole 45. Is in the position of.

In addition, stopper walls 41a and 4lb are formed at both ends of the ring 41 in which a part of the circumferential direction is cut, and the inner tooth gear 43 on the lever base plate 42 is formed. In an adjacent position, a cutout 47 is formed to avoid interference with the intermediate gear support shaft 26. In addition, the lower surface of the lever bottom plate 42 is formed so that the fall prevention hook 48 for engaging the inner lever gear-mounted rotary lever 40 so as not to come off from the diaphragm blade drive mechanism attachment portion 20 is formed. have.

As shown in FIG. 4, the rotary lever support shaft is formed so that the center hole 45 formed in the lever bottom plate 42 protrudes toward the center of the bottom plate 21 in the diaphragm wing drive attachment part 20. 25, the rotary lever 40 with the inner tooth gear is attached so as to rotate its rotation axis on the aperture substrate 10 in a direction orthogonal to the aperture substrate 10. As shown in FIG.

In this state, as shown in Figs. 8 to 11, the driving pins 44a and 44b are coupled to slide the respective long holes 13d and 12d of the iris blades 13 and 12, respectively, and the rotary lever 40 By rotating, the iris blades 12 and 13 can be driven to slide in opposite directions to each other.

In addition, the fall prevention hook 48 formed to protrude on the bottom surface of the rotary lever 40 slides on the back edge of the cutout portion 29 of the bottom plate 21 in the diaphragm blade drive mechanism attaching portion 20. By being coupled so as to be possible, the rotary lever 40 is fixed so as not to fall off from the diaphragm blade drive mechanism attaching part 20 at the time of assembly. In this state, the stopper walls 41a and 4lb at both ends of the ring 41 are allowed to contact the stopper protrusion 27, thereby limiting the rotation range of the rotary lever 40. As shown in FIG. In addition, the intermediate gear support shaft 26 protrudes upward from the cut portion 47 formed in the lever bottom plate 42 so as not to interfere with the rotary lever 40 while the rotary lever 40 rotates in the rotation limited range. have.

The intermediate gear 60 is provided with an air gear 61 and a small gear 62 (see Fig. 8) integrally on the same axis, and as shown in Fig. 5, the center hole. (66) is attached to the intermediate gear support shaft 26 so as to rotate on the aperture substrate 10, in which state the small gear 62 is engaged with the inner gear 43 of the rotary lever 40. (咬合: engagement, hereinafter referred to as occlusal).

The motor attachment cover 80 is as shown in FIG. 6 so as to cover the rotary lever 40 and the intermediate gear 60 after assembling the rotary lever 40 and the intermediate gear 60 as described above. As it is attached to the iris blade drive mechanism attachment portion 20 serves as a gear case cover (gear case cover).

The motor attachment cover 80 includes a cover main plate 81 having a size of a standing circumferential wall 22 of the diaphragm vane driving mechanism attaching unit 20, and has a cylindrical surface on the upper surface of the cover main plate 81. A motor attaching wall 82 and a circuit board attaching wall 88 each having a shape of i) are formed to protrude. The cylindrical motor attachment wall 82 is provided with a cutout at a position facing 180 °, and a lock piece 85 for fixing the motor is formed at the cutout. In addition, an opening 86 for inserting the pinion 112 of the stepping motor 110 is formed in the portion on the cover main plate 81 surrounded by the cylindrical motor attachment wall 82.

In addition, a cord clamp 83 is formed at a position on the cover main plate 81 that does not interfere with motor attachment. The cord clamp 83 has a substantially W-shaped frame surrounding the cord accommodating part 83a. When the cord is inserted into the cord accommodating part 83a through a cut part 83b near the base end, the cord clamp 83 is formed. The cord is prevented from being pulled out by the fall prevention piece 83c.

The motor attachment cover 80 is accurately inserted by inserting the positioning pin 23 on the diaphragm blade drive mechanism attachment portion 20 side into a positioning hole not shown in the drawing formed on the lower surface side of the cover main plate 81. Aperture blade drive mechanism is attached by engaging a lock pawl 24 on the aperture blade drive mechanism attachment portion 20 side with a lock hole 84 that is positioned and is opened in the cover main plate 81. It is attached to the part 20 very precisely.

As shown in Fig. 7, inside the motor mounting wall 82 of the motor mounting cover 80, the rotating shaft 111 (see Fig. 8) is orthogonal to the aperture substrate 10. A stepping motor 110 is attached. The stepping motor 110 accommodates the rotating mechanism part inside the cylindrical housing, and the pinion 112 is attached to the rotating shaft 111 which protrudes from the end surface of the housing. In addition, an attachment bracket 113 having a groove portion 113a to which the lock piece 85 is engaged is formed at an end portion of the housing on the rotating shaft 111 side, and the side portion of the housing is provided. The circuit board 115 is attached to this.

In this way, the lock piece 85 is coupled to the groove portion 113a of the attachment bracket 113 in a state in which the stepping motor 110 is attached to the motor attachment cover 80. The circuit board 115 is also supported on the circuit board attaching wall 88. In addition, a pinion 112 attached to the rotating shaft 111 of the stepping motor 110 is inserted into the motor attachment cover 80 through an opening 86 formed in the motor attachment cover 80. As shown in Fig. 8, the inner side of the motor attachment cover 80 is engaged with the standby gear 61 of the intermediate gear 60.

Therefore, the driving force input from the pinion 112 constituting the gear reduction mechanism 70 is transferred to the inner tooth gear 43 through the air gear 61 and the small gear 62 of the intermediate gear 60. The rotary lever 40 is rotated so as to be transmitted.

As shown in FIG. 1, a cord 116 extends from the circuit board 115 of the stepping motor 110, and a connector 117 is provided at the front end of the cord 116. ) Is attached. Similarly, a circuit board 125 is attached to an actuator 120 for driving an optical filter, and a connector 127 is attached to the tip of a cord 126 extending from the circuit board 125.

In addition, the diaphragm absorbs the backlash between the inner tooth gear 43 and the pinion 112 by rotationally pressing the rotary lever 40 with the inner tooth gear in one direction. A backlash mechanism is provided. The non-backlash mechanism exerts a magnetic attraction force with each other, and a magnet 50 and a magnetic pin (magnetic member) which pressurize the rotary lever 40 by this magnetic attraction force. A magnet 50 is attached to the inner surface side of the cover with motor 80, and formed in the pin hole 49 formed in the edge portion 41d of the rotary lever 40. The magnetic pin 51 is inserted and fixed.

In this case, the area | region which presses the rotation lever 40 by magnetic force is set in the rotation area | region of the small aperture side rotation lever 40 with a small diaphragm mouth at least. That is, as shown in FIG. 11, the positional relationship between the magnet 50 and the magnetic pin 51 is set so that the necessary magnetic attraction force Q is applied between the magnet 50 and the magnetic pin 51 in the small aperture stage. .

In this aperture device, as shown in Figs. 10 and 11, the pair of drive pins 44a and 44b is a straight line when the pair of drive pins 44a and 44b are on a straight line perpendicular to the slide direction of the aperture blades 12 and 13, respectively. A small aperture side (the range of θ2 in FIG. 11) and the other side, which is set to K, and whose one side is made smaller with the reference line K therebetween. When the control aperture side (the range of θ1 in FIG. 10) is used to increase the aperture diameter, the rotational area of the driving pins 44a and 44b is smaller than the small aperture side as shown in FIG. Reference line K such that the rotational angle range θ2 from the reference line K at)) becomes larger than the rotational angle range θ1 from the reference line K at the control opening side (open side). ) Is set to bias. For this reason, the stroke of the diaphragm wings 12 and 13 from the reference line K also becomes larger than the stroke S1 from the reference line K on the non-aperture side from the reference line K on the control aperture side. It is supposed to be. In Fig. 12, O is the rotational center of the drive pins 44a (the same applies to 44b), and R is the rotational track of the drive pins 44a.

By setting the rotation area of the drive pins 44a and 44b in this way, even if the resolution of the stepping motor 110 (corresponding to the rotation angle of the drive pins 44a and 44b per step of the stepping motor) is the same, Aperture aperture at the side can be finely controlled. This point is explained.

When the rotation radius of the drive pin 44a is r and the rotation angle of the drive pin 44a from the reference line K is θ (where θ <90 °), it is determined from the reference line K. The moving stroke S of the diaphragm wings 12 and 13 by the drive pin 44a is

S = rsinθ

Becomes

As can be seen from the equation S = rsinθ, the change amount ΔS of the moving stroke of the diaphragm blade with respect to the unit change amount Δθ of θ becomes smaller as θ becomes larger. Since the value of Δθ is the rotation angle of the drive pin 44a per step of the stepping motor, driving the aperture blades 12 and 13 in a region having a large value of θ makes the aperture blades 12 and 13 finely positioned. It can be controlled.

In the diaphragm apparatus of this embodiment, in order to realize this, the rotation angle range (theta) 2 from the reference line K on the small aperture side is set to the rotation angle range (the rotation angle range from the reference line K on the control aperture side) It is set to be biased from the reference line K so as to be larger than θ1), and it is possible to achieve high precision of the aperture control in the required area (small aperture area) easily by using such a setting method. can do.

In Fig. 13, (a) shows the rotation angle range of the driving pin in the case of the present embodiment and (b) in the case of the comparative example. In the case of the comparative example of (b), the rotation angle range (theta) b from the reference line K at the small opening side (closed side) and the rotation angle range from the reference line K at the control opening side (opening side) ( ? b) is set to be the same.

In this way, the iris blades 12 and 13 can move only the same stroke Sb from the reference line K on both the small aperture side and the control aperture side, and are driven under the same conditions on the small aperture side and the control aperture side.

On the other hand, as shown in (a), the entire rotation angle range of the drive pin 44a hardly changes, and in the present embodiment in which the rotation angle range is shifted to the small aperture side, as shown in FIG. Outside the range θ1 (the stroke N1 of the iris blade) driven under the same conditions on the small aperture side and the control aperture side, the drive range θ3 peculiar to the small aperture side (part of N3 in the stroke of the iris blade) Equivalent to) can be set. Since this range θ3 belongs to a region where θ is large in the previous equation S = rsinθ, ΔS becomes smaller than Δθ. That is, even if the drive pin 44a rotates by the same step angle, the displacement amount (DELTA) S of an aperture blade becomes small. Therefore, high precision positioning control becomes possible.

As described above, according to the aperture device of the present embodiment, since the aperture blades 12 and 13 are driven by the stepping motor 110, fine and subtle aperture control can be easily performed. In addition, since the reduction gear mechanism 70 is inserted between the rotary shaft 111 of the stepping motor 110 and the rotary lever 40 for driving the iris blades 12 and 13, the number of step divisions of the stepping motor 110 is achieved. It is possible to finely control the diaphragm opening with a resolution of (step minute) or more. In addition, since the reduction mechanism is geared instead of frictional, the difference in the rotational positional relationship between the stepping motor 110 and the rotary lever 40 may occur even when an impact is applied. It has no shock resistance and high reliability.

In addition, the reduction gear mechanism 70 is formed integrally with the pinion 112 attached to the rotating shaft 111 of the stepping motor 110 and the rotating lever 40, and through the pinion 112 and the intermediate gear 60. Since it is comprised by the interlocking inner gear 43, the stepping motor 110 can be arrange | positioned as biased as possible to the rotation center position of the rotation lever 40. As shown in FIG. Therefore, although the reduction gear mechanism 70 is inserted between the stepping motor 110 and the rotary lever 40, the compactness of the drive system arrangement can be realized.

In addition, when the reduction gear mechanism consists of an outer tooth gear and a pinion, a stepping motor is arrange | positioned in the position away from the rotation center of a rotary lever. Alternatively, the intermediate gear protrudes outward from the rotation center of the rotary lever even if the stepping motor is placed inside (as close to the center of rotation of the rotary lever) as possible by inserting an intermediate gear between the outer gear and the pinion. Becomes Therefore, the dimensions of the drive system tend to be large, making it difficult to realize a compact arrangement. This also makes it easier to interfere with other components, making it difficult to design to avoid them. In this regard, the diaphragm device of the present embodiment can realize a compact arrangement while increasing the degree of freedom in design by using the inner tooth gear 43.

In addition, since the driving pins 44a and 44b are formed at a position close to the end face of the ring 41 on which the inner tooth gear 43 is formed, the support rigidity of the driving pins 44a and 44b is maintained. It is possible to increase the radius of rotation of the drive pins 44a and 44b while increasing the slide stroke of the aperture blades 12 and 13.

In the diaphragm according to the present embodiment, first, the rotary lever 40 with the inner tooth gear is attached to the support shaft 25 for the rotary lever of the diaphragm drive mechanism attaching portion 20, and then the intermediate gear 60 is attached. To the support shaft 26 for intermediate gears, and then the motor attachment cover 80 is assembled on the diaphragm drive mechanism attachment portion 20, and then the pinion 112 is formed in the motor attachment cover 80. The assembly can be completed simply by attaching the stepping motor 110 to the motor attachment cover 80 while inserting it from the 86 and engaging the intermediate gear 60.

In the aperture device of the present embodiment, the intermediate gear 60 is inserted between the pinion 112 on the stepping motor 110 side and the inner gear 43 on the rotation lever 40 side to increase the reduction ratio. Since it is possible to, the movement of the stepping motor 110 can be transmitted to the rotary lever 40 as a fine movement. Therefore, even if the number of step divisions of the stepping motor 110 is set not to be somewhat subdivided, the aperture blades 12 and 13 can be finely positioned to control the aperture with high precision.

In addition, since the intermediate shaft support shaft 26 is formed on the diaphragm substrate 10, the intermediate gear 60 is simultaneously assembled together with the rotary lever 40 with the inner tooth gear on the diaphragm substrate 10, The motor attachment cover 80 can be assembled thereon, so that the assembly can be simplified even if the intermediate gear 60 is present.

In other words, it is difficult to form the support shaft 26 for the intermediate gear on the diaphragm substrate 10, but the cutting part 47 is formed in the rotary lever 40 with the inner tooth gear to penetrate the cutting part 47. An intermediate gear support shaft 26 was formed on the substrate 10, whereby the intermediate gear 60 was first attached to the aperture substrate 10 side. By doing so, assembling performance can be improved compared with the case where the intermediate gear 60 is attached to the motor attachment cover 80 side.

In this diaphragm, the backlash from the pinion 112 to the inner tooth gear 43 is absorbed by the non-backlash mechanism composed of the magnet 50 and the magnetic pin 51, at least in the small aperture side region. It is possible to adjust the aperture with high precision in the required area (especially the small aperture side).

In addition, since the magnet 50 and the magnetic pin 51 are employed as the elements constituting the non-backlash mechanism, high precision control is possible by adding a very simple configuration. For example, as a non-backlash mechanism, it is also conceivable to pressurize the rotary lever with the inner tooth gear by a spring, but this has a drawback that the attachment of the spring is complicated. In this regard, in the case of the diaphragm device of the present embodiment, when the rotary lever 40 with the inner gear gear is rotated and pressurized only in the region of the small aperture side, the magnet 50 and the magnetic pin 51 are sufficient in terms of performance. In combination with the above, a simple configuration and sufficient performance are obtained.

In addition, by setting the rotation angle ranges of the drive pins 44a and 44b to be biased toward the small aperture side and the non-aperture side, the aperture aperture at the small aperture side can be finely controlled even when the resolution of the stepping motor 110 is the same as described above. can do.

In addition, as described above, the following advantages are also obtained by increasing the resolution of the aperture control on the small aperture side. That is, in many types of aperture devices, an ND filter (light intensity filter) is attached to a part of the aperture blades in order to increase the resolution of light quantity control on the small aperture side. Since this ND filter is expensive in itself and needs to be attached to the surface of the diaphragm blade which requires high precision, it has become a factor of the cost increase of the whole diaphragm apparatus.

However, in the diaphragm apparatus of this embodiment, the stepping motor 110 is used, the gear reduction mechanism 70 is used, and the mechanism which removes backlash at the time of a small aperture is further provided. The resolution on the small aperture side can be remarkably improved by shifting the rotation angle range to the small aperture side. This makes it possible to stop using the ND filter similarly to the present embodiment. In other words, it is possible to ensure the control resolution of the diaphragm blade on the small aperture side without using the ND filter. This can contribute to cost down and productivity improvement by eliminating the need for an expensive ND filter and eliminating the task of attaching an ND filter that requires high precision to the diaphragm blade.

In the above embodiment, the magnet 50 is provided on the fixed side and the magnetic pin 51 is provided on the movable side. However, the magnet 50 and the magnetic pin 51 are provided oppositely. Also good. That is, the magnet 50 may be provided on the rotation lever 40 side, and a magnetic member such as a magnetic pin may be provided on a fixed side such as the diaphragm substrate 10 or the motor attachment cover 80. Further, the magnetic member may be made of a magnet.

In addition, in the above embodiment, an example in which the intermediate gear 60 is installed in the gear reduction mechanism 70 is shown. However, the intermediate gear is omitted, and the pinion 112 on the stepping motor 110 side is directly inside the rotary lever 40. You may engage with the toothed gear 43.

15 to 18 are schematic diagrams of the diaphragm of the second embodiment without using an intermediate gear. Fig. 15 is an exploded perspective view showing the overall configuration, Fig. 16 is a perspective view showing a state in which a rotating lever is attached to an aperture blade drive mechanism attachment portion on an aperture substrate, and Fig. 17 is a motor on the aperture blade drive mechanism attachment portion in Fig. 16. 18 is a perspective view showing a state in which an attachment cover is attached, and FIG. 18 is a perspective view showing a state in which a stepping motor is attached on the motor attachment cover in FIG.

The difference from the first embodiment is that there is no support shaft for the intermediate gear in the diaphragm blade drive mechanism attachment portion 220 of the diaphragm substrate 210 due to the elimination of the intermediate gear, and the inner tooth gear 43 of the rotary lever 40. ), The attachment position of the stepping motor 110 is changed by the relationship of directly engaging the pinion 112, and thus the shape of the motor attachment cover 280 is changed. The other point is the same configuration as the first embodiment, the same reference numerals are assigned to the same components, and description thereof will be omitted.

When the intermediate gear is omitted in this way, since the reduction ratio of the reduction gear mechanism becomes smaller, the precision of position control of the diaphragm decreases somewhat, but the accuracy decreases due to the absence of the intermediate gear by improving the resolution of the stepping motor 110. You can supplement.

1 is an exploded perspective view showing the entire configuration of an aperture device according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing the structure of an aperture board which is a main part of the aperture device of the first embodiment.

3 is a perspective view showing the configuration of a rotary lever as a main part of an aperture device.

Fig. 4 is a perspective view showing a state in which a rotating lever is attached to an aperture blade drive mechanism attaching portion on an aperture substrate.

FIG. 5 is a perspective view showing a state where an intermediate gear is attached to an upper side of the rotary lever in FIG.

FIG. 6 is a perspective view showing a state where a motor attachment cover is attached on the diaphragm wing drive attachment portion in FIG. 5; FIG.

FIG. 7 is a perspective view illustrating a state in which a stepping motor is attached to the motor attachment cover of FIG. 6. FIG.

Fig. 8 is a perspective view showing only the elements of the drive system of the iris blade separated from each other.

9 is a plan view of the drive system of the diaphragm blade viewed from the diaphragm blade side.

Fig. 10 is a plan view showing the relationship between the rotational position of the rotary lever and the aperture blades when the aperture is fully open (maximum aperture);

Fig. 11 is a plan view showing the relationship between the rotational position of the rotary lever and the diaphragm blades when the diaphragm is fully closed (the minimum diaphragm).

12 is a view showing the relationship between the position of the drive pin of the rotary lever and the rotation angle range of the rotary lever.

Fig. 13 is a diagram showing the difference between the rotation range of the rotation lever in this embodiment and the rotation angle range of the rotation lever in the comparative example.

FIG. 14 is a view for explaining the advantage of the difference between the two parts in the small opening side and the control opening side with respect to the reference line of the rotational angle range of the rotating lever.

Fig. 15 is an exploded perspective view showing the entire configuration of the aperture device according to the second embodiment of the present invention.

Fig. 16 is a perspective view showing a state in which a rotating lever is attached to an aperture blade drive mechanism attaching portion on an aperture substrate.

FIG. 17 is a perspective view showing a state where the motor attachment cover is attached on the diaphragm wing drive attachment portion in FIG. 16; FIG.

FIG. 18 is a perspective view showing a state where a stepping motor is attached on the motor attachment cover in FIG. 17; FIG.

Explanation of symbols on the main parts of the drawings

10: aperture substrate 11: opening

12: aperture wing 12d: long hole

13: aperture wing 13d: long hole

20: drive mechanism attachment portion for the diaphragm blade

25: support shaft for rotary lever

26: support shaft for intermediate gear

40: Rotating lever with inner gear

43: inner gear gear 44a, 44b: drive pin

47: cutting part

50: magnet (non-backlash mechanism)

51: magnetic pin (non-backlash mechanism)

60: middle gear 61: standby gear

62: small gear 70: gear reduction mechanism

80: cover with motor 86: opening

110: stepping motor 111: rotating shaft

112: pinion 210: aperture substrate

220: Aperture blade drive mechanism attachment portion

280: cover with motor

Claims (6)

An diaphragm substrate having an opening for forming an optical path, Two aperture blades which are formed to slide linearly on the aperture substrate and are reciprocally slide-driven in opposite directions to iris slide the optical path; A rotary lever attached to the diaphragm substrate so as to rotate its rotation axis in a direction orthogonal to the diaphragm substrate for driving the diaphragm blade; It is formed to protrude at a position spaced apart from the rotation axis on the rotary lever, each is formed in each of the aperture blades and sliding in a long long hole in a direction orthogonal to the slide direction of the aperture blades (sliding) A pair of driving pins coupled to each other, for rotating the aperture blades in a reverse direction to each other by rotating the rotary lever; A stepping motor attached to the diaphragm substrate in a direction orthogonal to the diaphragm substrate in order to rotate the rotary lever; A reduction gear mechanism inserted between the rotary lever and the rotary shaft of the stepping motor; Respectively, The reduction gear mechanism, An inner tooth gear (pinion) attached to the rotating shaft of the stepping motor and the inner lever integrally formed on the rotating lever and indirectly engaged with the pinion directly or through an intermediate gear. Diaphragm device, characterized in that consisting of a tooth gear. The method according to claim 1, A diaphragm blade driving mechanism attaching portion is formed on the diaphragm substrate, and the inner lever gear is attached to a support shaft for a rotating lever formed to protrude on the diaphragm blade driving mechanism attaching portion. lever) is supported to rotate, Meanwhile, a motor attachment cover is assembled to cover the rotary lever to which the inner tooth gear is attached to an upper portion of the diaphragm wing mechanism attaching part. The stepping motor is attached to the outside of the motor attachment cover, A pinion attached to the rotating shaft of the stepping motor is inserted into the motor attachment cover through an opening formed in the motor attachment cover, and the pinion is inside the motor attachment cover to form the inner gear. The aperture device, characterized in that the interlocking directly or indirectly through the intermediate gear. The method of claim 2, The reduction gear mechanism is composed of an intermediate gear inserted between the pinion, the inner tooth gear, and the pinion and the inner tooth gear, The intermediate gear is integrally provided with a small gear that is engaged with the pinion gear and the inner tooth gear that engage with the pinion on the same axis. On the other hand, on the diaphragm wing drive attachment portion, an intermediate portion penetrates the rotary lever through a cut portion on the rotary lever adjacent to the support shaft for the rotary lever and formed inside the gear gear. The gear support shaft is formed to protrude, An aperture device, characterized in that the intermediate gear is supported by the intermediate gear support shaft to rotate. The method according to any one of claims 1 to 3, A non-backlash mechanism is provided which absorbs backlash between the inner tooth gear and the pinion by rotationally pressing the rotating lever with the inner tooth gear in one direction. The non-backlash mechanisms are provided on one side and the other side of the rotating lever side and the fixed side such as the diaphragm substrate and the motor cover, respectively, and exert a magnetic force on each other. It is composed of a magnet and a magnetic member for rotating and pressing the rotary lever by magnetic force. An area for rotationally pressing the rotary lever by the magnetic force is set in the rotation area of the rotary lever at the small diaphragm side having a small diaphragm opening. Aperture device. The method according to any one of claims 1 to 3, The pair of drive pins are arranged at a position of rotation center and point symmetry of the rotary lever, When the pair of drive pins are on a straight line orthogonal to the slide direction of the diaphragm blade, the straight line is used as a reference line, and the diaphragm diameter is reduced on one side with the reference line therebetween. When the small aperture side and the other side to be used are the diaphragm side which enlarges a diaphragm aperture, The rotation region of the drive pin is set to be biased from the reference line so that the rotation angle range from the reference line on the small aperture side is larger than the rotation angle range from the reference line on the control aperture side. The method of claim 4, wherein The pair of drive pins are arranged in a position of rotational center and point symmetry of the rotary lever, When the pair of drive pins are on a straight line orthogonal to the slide direction of the diaphragm blade as a reference line, a small aperture side and the other side having one side smaller in aperture diameter with the reference line therebetween When the diaphragm side is used to increase the aperture diameter, The rotation region of the drive pin is set to be biased from the reference line so that the rotation angle range from the reference line on the small aperture side is larger than the rotation angle range from the reference line on the control aperture side.

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