JP6068983B2 - Optical path stop device for projector - Google Patents

Description

  The present invention relates to an optical path stop device for a projector for home use or business for projecting images and characters on a screen.

  As an optical path stop device for a projector, there is an apparatus that opens and closes an optical path by attaching a light shielding plate to each of two driving members, rotating the driving members in opposite directions, and moving the two light shielding plates closer to or away from each other. It is known (see, for example, Patent Document 1). In this device, the two drive members are engaged with each other by gears formed on the outer peripheral portion, and one drive member is rotated by a motor to rotate the drive members in opposite directions.

  In this type of optical path opening / closing device, a driving member using a gear is employed in order to make the two light shielding plates approach or separate from each other. Here, the gear is made of resin for the purpose of suppressing the meshing noise of the gear and reducing the cost. However, since the inside of the projector is in a high temperature environment where a heat generating member such as a light source exists, problems such as thermal expansion of resin parts occur. In the above-described apparatus, one drive member is provided with an urging means so that the drive member can operate stably even when the component is thermally expanded. However, as a result, the number of parts increases and the configuration of the entire apparatus becomes complicated.

  Further, in this optical path opening and closing device, in order to avoid deformation of the resin component in a high temperature environment, as a measure for shielding the component from the light source, it can be attached so that the direction in which the blade extends is opposite to the driving member. .

JP 2008-145949 A

  The present invention has been made in view of the above problems, and provides an optical path stop device for a projector that opens and closes an optical path by approaching or separating two blades without using a gear meshing mechanism. For the purpose.

  The optical path stop device of the present invention rotates about a rotation axis extending in a direction intersecting with the optical axis direction of the optical path between a closed position that blocks the optical path of the projector and an open position that opens the optical path. A blade, an arm that rotates the blade, and a drive mechanism that drives the arm, wherein the drive mechanism includes a linearly moving member that rotates the arm and that linearly moves. To do.

  According to the present invention, since the two blades are simultaneously opened and closed via the arm driven by the linearly moving linearly moving member, it is not necessary to use a gear molded product. Therefore, it is not necessary to select and design parts in consideration of gear meshing sound.

  The direction intersecting with the direction of the optical axis does not mean that it intersects (intersects) the optical axis. Typically, the state is such that the direction is orthogonal to the optical axis. However, it is not limited to intersecting at right angles.

  The arm is preferably a lever having one end connected to the blade. In this case, the number of parts can be reduced. However, a link mechanism including a plurality of arms may be used.

In the present invention, it is preferable to further include an elastic member that urges the arm and / or the linear motion member in one direction to remove the play of the drive mechanism of the arm.
A spring, rubber, or the like can be used as the elastic member.
In particular, the arm has one end connected to the blade, the other end pushed by the linear motion member, a central portion supported by the rotating shaft, and a tension spring between the arm and the linear motion member. It is preferably stretched.

  In this invention, it is preferable that the said drive mechanism has a rotation motor and a screw feed mechanism, or has a shaft motor.

  As a mechanism for linearly moving the linear motion member, a combination of a rotary motor (such as a stepping motor) and a screw feed mechanism (such as a lead screw) or a linear motor (such as a shaft motor) can be used. Since the linear motor has a higher operating speed than the rotary motor + screw feed mechanism, it is particularly suitable for a home projector. In the case of a business projector, there is no particular problem with the operating speed of the stepping motor + screw feed mechanism. Furthermore, the accuracy and speed of the stop position can be controlled with high resolution by changing the specifications (lead pitch) of the lead screw.

  The arm and the linear motion member can be pulled toward each other by the tension spring, and free rotation of the arm can be suppressed. Since the arm is pushed by the linearly-moving linearly-moving member and rotates, the contact portion between both members slips. Therefore, by pulling the arm and the linear motion member toward each other with a tension spring, both of them come into sliding contact more firmly, eliminating backlash and performing linear motion of the linear motion member on the arm. It can be reliably transmitted to the rotational movement.

The one end and the other end of the arm do not mean a strict end, but mean one side and the other side with respect to the rotation axis.
As the tension spring, a coil spring or rubber can be used, but since it is used in a high temperature environment, it needs to have heat resistance.

  In the present invention, the contact area between the arm and the linear motion member can be reduced as much as possible if the arm and the linear motion member are brought into contact with each other between the flaky projections. Can be reduced.

  In this invention, it is preferable that the said linear motion member pushes and rotates the said arm via the roller which rotates.

  When the linearly-moving linearly-moving member directly pushes the rotating arm, the contact surface of both members slips, which causes mechanical resistance and noise. Therefore, if a roller is arranged at a portion where the linear motion member and the arm are in contact with each other and the both are in contact with each other via this roller, slippage is alleviated and mechanical resistance and noise can be reduced.

  Further, when the rail on which the roller slides is formed on the linear motion member, the roller rotates stably, so that the arm can be rotated smoothly.

  In the present invention, the arm is two arms having one end rotatably connected and having a link mechanism, and the other end of one arm is rotatably connected to the linear motion member. The blade is connected to the other end of the other arm and supported so as to be rotatable around a rotation shaft extending in a direction intersecting the direction of the optical axis. By the linear motion of the linear motion member, The two arms can be opened and closed, and the arm connected to the blade can be driven.

  In this invention, it is preferable that the said blade | wing, the said arm, and a drive mechanism are arrange | positioned in the space of the both sides which separated the attachment plate (base plate).

  In this case, the light source is disposed in the space on the side where the blades are present with respect to the mounting plate, and components such as the arm and the moving frame are disposed in the opposite space. Therefore, components such as the arm and the moving frame can be protected from a high temperature environment. Also in this case, it is not necessary to form an opening or the like through which the blade passes through the ground plate (mounting plate).

  As is clear from the above description, according to the present invention, since the two blades are simultaneously opened and closed via the arm driven by the linearly moving linear member, it is not necessary to use a gear molded product. Therefore, it is not necessary to select and design parts in consideration of gear meshing sound. In addition, if the arm and the linear motion member are configured to be pulled toward each other by a spring or the like, the sliding movement of both of them can be suppressed and the sliding motion can be made strong, and the linear motion of the linear motion member can be changed to the rotational motion of the arm. I can tell you with certainty.

It is a bottom view of the optical path diaphragm apparatus for projectors concerning the 1st Embodiment of this invention. FIG. 2 is a perspective view of the optical path stop device of FIG. 1. It is a figure which shows the structure of the blade | wing and arm of the optical path diaphragm | throttle device of FIG. 1, FIG. 3 (A) is a front view, FIG.3 (B) is a side view. It is a figure which shows the structure of the moving frame of the optical path stop apparatus of FIG. 1, FIG. 4 (A) is a perspective view, FIG.4 (B) is a bottom view. FIG. 5A is a bottom view showing the fully closed state of the optical path stop device of FIG. 1, and FIG. 5B is a bottom view showing the fully opened state. 6A is a perspective view showing the fully closed state of the optical path stop device of FIG. 1, and FIG. 6B is a perspective view showing the fully opened state. It is a perspective view of the optical path diaphragm apparatus for projectors concerning the 2nd Embodiment of this invention. It is a bottom view of the optical path diaphragm apparatus for projectors concerning the 3rd Embodiment of this invention. FIG. 9A is a bottom view showing the fully closed state of the optical path stop device of FIG. 8, and FIG. 9B is a bottom view showing the fully opened state. It is a bottom view of the optical path diaphragm apparatus for projectors concerning the 4th Embodiment of this invention. It is a bottom view which shows the fully closed state of the optical path diaphragm apparatus of FIG. It is a bottom view of the optical path diaphragm apparatus for projectors concerning the 5th Embodiment of this invention. It is a perspective view which shows the structure of the blade | wing and arm of the optical path stop apparatus of FIG. It is a figure which shows the moving frame of the optical path diaphragm | throttle device of FIG. 12, (A) is a perspective view, (B) is a bottom view. 14A is a bottom view showing the fully closed state of the optical path stop device of FIG. 12, and FIG. 14B is a bottom view showing the fully opened state.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A projector (business) optical path stop device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a bottom view of the optical path stop device, and FIG. 2 is a perspective view.
The optical path stop device 1 includes a pair of left and right blades 20L and 20R, left and right arms 30L and 30R to which the blades 20 are attached, and a drive mechanism 50 that drives both arms 30 simultaneously. These are attached to the mounting plate 10. The arm 30 is rotated around a rotation axis (reference numeral 41) extending in a direction intersecting the direction of the optical axis A of the optical path by the driving mechanism 50, and the pair of blades 20 are closed to block the optical path, and the optical path is Move between open positions to open. The drive mechanism 50 mainly includes a moving frame 60 that linearly moves in the direction in which the optical axis A extends to rotate both arms 30 around the rotating shaft 41 and a motor 80 that drives the moving frame 60. .
In the following description, the front-rear direction indicates the optical axis direction of the light source, and the light source side is the rear and the opposite side is the front. The horizontal direction and the vertical direction indicate the horizontal direction and the vertical direction of the drawing.

The mounting plate 10 is a horizontally-long rectangular plate-like member that is symmetrical with respect to the optical axis A, and the front and rear edges are parallel to the direction orthogonal to the optical axis A. A rear piece 11 is provided at the rear edge of the mounting plate 10 and is bent downward substantially at a right angle. A motor 80 is attached to the rear piece 11 as will be described later. A front piece 13 that is bent substantially at a right angle downward is also provided at the center of the front edge of the mounting plate 10 excluding both ends. As will be described in detail later, the moving frame 60 moves straight between the front and rear pieces 13 and 11.
The mounting plate 10 can be adapted to the specifications of the projector to which the optical path stop device is mounted by forming guide bosses, screw holes, and the like.

Next, the structure of the pair of blades 20 and the arm 30 to which the blades 20 are attached will be described with reference to FIG. The left and right blades 20 and the arm 30 have a symmetrical shape with respect to the optical axis A. 3A is a front view and FIG. 3B is a side view. Although the right wing is shown in this figure, the left wing has a symmetrical shape of the right wing.
As shown in FIG. 3A, the blade 20 has a substantially L-shaped flat plate shape, and includes a light-shielding portion 21 and a base portion 23 that extends substantially at right angles from one end of the light-shielding portion 21. A bent portion 25 that is bent obliquely backward and at an obtuse angle is formed on opposite sides of the light shielding portions 21 of the left and right blades. A cutout 26 having a semicircular cross-sectional shape is formed at substantially the center of each bent portion 25. This notch 26 is located on the optical axis A, and forms the minimum aperture when the left and right blades 20 are in the closed position.

  The arm 30 includes a base portion 31 that is rotatably supported by the mounting plate 10 and an operating portion 35 that is in sliding contact with a moving frame 60 described later. The base 31 has a substantially rectangular parallelepiped shape, and has a flat upper surface 31a and a front surface 31b that are orthogonal to each other. A through hole 33 penetrating in the vertical direction is formed in the vicinity of the boundary between the base portion 31 and the operating portion 35. As shown in FIGS. 1 and 2, the base 31 is supported on a lower surface of the front corner of the mounting plate 10 by a support column 41 extending in a direction intersecting the direction of the optical axis A. The support column 41 has a head portion and a shaft portion, and an annular groove is formed at the end of the shaft portion. Further, the central portion of the shaft portion has a small diameter and acts as a grease reservoir. The support column 41 is inserted from the upper surface of the mounting plate 10 and passes through the through hole 33 of the arm 30. Then, an E-ring is attached to the groove at the tip of the shaft protruding from the base 31 via a washer. As a result, the arm 30 can rotate around the support column 41.

  The operating portion 35 of the arm 30 protrudes obliquely from the rear corner of the base portion 31 in the rearward direction and toward the center. As shown in FIG. 3B, the operating portion 35 is formed in a stepped shape that decreases in two steps toward the tip. The distal end portion 36 of the operating portion 35 is composed of a semi-circular thin upper piece 36a and a lower piece 36b formed at a predetermined interval. As will be described later, the tip portion 36 is a portion that receives a force from the moving frame 60 of the drive mechanism 50, and is formed so as to reduce the contact area with the moving frame 60 in consideration of the contact resistance with the moving frame 60. Has been. A protrusion 43 is formed on the lower surface of the distal end portion 36 and is engaged with one end of a coil spring 91 for connecting to the moving frame 60.

  In the blade 20, the base portion 23 is attached to the front surface 31 b of the base portion 31 of the arm 30 with screws 45 so that the light shielding portion 21 is on the inner side (optical axis side). The arm 30 and the blade 20 are positioned by a positioning boss. In this example, the blade 20 is mounted such that the light shielding portion 21 faces the same direction (downward) as the bending direction of the front and rear pieces 13 and 11 of the mounting plate 10, but the second embodiment shown in FIG. It can also be mounted in the opposite direction as in the example.

  As described above, the drive mechanism 50 moves linearly in the direction in which the optical axis A extends to move the arms 30 around the rotation shafts (posts 41), and the movement frame (linear motion member) 60. And a motor 80 for driving the frame 60.

The structure of the moving frame will be described with reference to FIG. 4A is a perspective view, and FIG. 4B is a bottom view.
The moving frame 60 is a horizontally long, substantially rectangular parallelepiped, left-right symmetric shape, and includes left and right block portions 61L and 61R and a front wall portion 63 between both block portions. The moving frame 60 is made of a phenol resin having heat resistance and slidability. A female screw 65 penetrating in the front-rear direction in parallel with the optical axis A is formed at a position of the front wall portion 63 at the center in the left-right direction of the moving frame 60. Further, a boss 67 is provided below the female screw 65 so as to protrude rearward.

  Further, on the outer surfaces of the left and right block portions 61, side edge portions 69 are formed that slide with the operating portion 35 of the arm 30 described above. The side edge portion 69 includes a thin upper piece 69a and a lower piece 69b formed at a predetermined interval. Further, the left and right block portions 61L and 61R are formed with openings 71 penetrating in the vertical direction. The opening 71 acts as a grease reservoir. And the guide hole 73 which penetrates this opening part 71 in the front-back direction in parallel with the optical axis A is opened. Further, a protrusion 75 is formed on the lower surface of the left and right block portions 61 so that the other end of the coil spring 91 for connecting to the arm 30 is locked.

  As described above, the moving frame 60 linearly moves between the front and rear pieces 13 and 11 of the mounting plate 10 by the stepping motor 80. As shown in FIGS. 1 and 2, the stepping motor 80 is attached to the rear piece 11 of the attachment plate 10 so that the output shaft penetrates forward. A lead screw 83 is connected to the output shaft. The lead screw 83 extends on the optical axis A in the plane, is screwed with a female screw 65 formed on the front wall of the moving frame 60, extends further forward, and has a tip at the center of the front piece 13 of the mounting plate 10. Further, it is supported via a bearing 85. Further, two guide pins 87 parallel to the lead screw 83 are bridged between the front and rear pieces 13 and 11 of the mounting plate 10. The guide pins 87 are inserted through the guide holes 73 of the left and right block portions 61 of the moving frame 60. When the lead screw 83 is rotated by the stepping motor 80, the moving frame 60 screwed to the screw 83 is guided by the guide pin 87 and linearly moves in the front-rear direction along the lead screw 83.

  Further, a coil spring 89 is fitted on a boss 67 formed on the front wall of the moving frame 60. The coil spring 89 is interposed between the boss 67 and the rear piece 11 of the mounting plate 10 to urge the moving frame 60 forward.

  The protrusions 75 of the left and right block parts 61 of the moving frame 60 and the protrusions 43 of the operating part 35 of the arm 30 are connected by a coil spring 91. Thereby, the left and right arms 30 and the moving frame 60 are pulled toward each other, and free rotation of the arms 30 is suppressed.

  In the optical path closed position, as shown in FIGS. 1 and 2, the moving frame 60 is located farthest behind the lead screw 83. The left and right arms 30 are biased in the direction of the moving frame 60 by the coil spring 91, and the base 23 of the left and right blades 20 is in contact with the front piece 13 of the mounting plate 10. Thereby, the light path is shielded by the light shielding portion 21 of the blade 20. In addition, the operating portions 35 of the left and right arms 30 extend obliquely rearward and inward, and the distal end portion 36 is in contact with the front surface of the moving frame 60. Further, the moving frame 60 is biased forward by a coil spring 89, thereby absorbing backlash between the lead screw 83 and the female screw 65 of the moving frame 60.

The optical path opening operation will be described with reference to FIGS. FIG. 5A is a bottom view showing a slightly opened state (indicated by a broken line) from the optical path fully closed state, and FIG. 5B is a bottom view showing the optical path fully opened state. FIG. 6A is a perspective view showing a fully closed state, and FIG. 6B is a perspective view showing a fully opened state. Since FIG. 6 is a view of the optical path stop device as viewed from the back side, the left-right direction is opposite to the left-right direction of FIG.
When the optical path is opened, the stepping motor 80 is driven to rotate the lead screw 83. Then, the moving frame 60 is guided by the guide pins 87 and moves forward along the lead screw 83 as shown in FIG. Thereby, the front surface of the moving frame 60 pushes the operating portion 35 of the arm 30 forward. Then, as shown by the imaginary line in FIG. 5A, the left and right arms 30 are in opposite directions around the support column 41 (the left arm 30L is counterclockwise in the figure, and the right arm 30R is clockwise in the figure). Begin to rotate. By the rotation of the arm 30, the moving frame 60 further moves the arm 30 while the side edge portion 69 slides along the side surface 35 a of the operating portion 35 from the distal end of the operating portion 35 of the arm 30 toward the base portion 31. Rotate.

  When the moving frame 60 moves to the foremost position, as shown in FIG. 5B, the arm 30 is rotated by approximately 90 °, and the left and right blades 20 are opened until they are substantially parallel to the optical axis of the optical path. At this time, the side edge portion 69 of the moving frame 60 reaches the root of the side surface 35 a of the operating portion 35 of the arm 30. At this time, slip occurs between the contact portions of the moving frame 60 and the arm 30. However, since the arm 30 and the moving frame 60 are urged toward each other by the coil spring 91, the operating portion 35 of the arm 30 and the moving frame 60 are more slidably in contact with each other, and backlash is suppressed. The linear motion of the moving frame 60 can be reliably transmitted to the rotational motion of the left and right arms 30. The opening / closing time of the blades from the fully closed state to the fully open state is about 1 second, which satisfies the opening / closing time required for a business projector.

  To close the optical path, when the stepping motor 80 is rotated in the reverse direction, the moving frame 60 moves rearward from the front piece 13 of the mounting plate 10, and the left and right arms 30 are in opposite directions (the left arm 30L is shown in FIG. 5). And the right arm 30R starts to rotate in the counterclockwise direction in FIG. When the moving frame 60 moves backward to the rear piece 11 of the mounting plate 10, the left and right arms 30 rotate until the base 21 of each blade 20 contacts the front piece 13 of the mounting plate 10.

This optical path stop device has the following advantages.
(1) Since a mechanism using a gear is not adopted as a mechanism for rotating the arm 30 to which the blades 20 are attached in opposite directions, no gear meshing sound is generated. Also, compared to the type that rotates the arm (blade) with a typical gear, there is no need for tooth forming parts.
(2) As the stepping motor 80, one having φ8 used as a countermeasure against noise can be used.
(3) Since the moving frame 60 and the left and right arms 30 are formed so as to be in sliding contact with each other in the smallest possible area, the sliding resistance between them can be reduced.
(4) Since the moving frame 60 is urged forward from the rear piece 11 of the mounting frame 10 by the spring 89, the play between the two can be absorbed.
(5) Since a grease reservoir is provided around the support 41 serving as the pivot of the arm 30 and the guide pin 87 on which the moving frame 60 slides (the opening 71 of the moving frame 60), the sliding between the parts Dynamic resistance can be reduced.
(6) Since the moving frame 60 and the left and right arms 30 are urged toward each other by the coil spring 91, the moving frame 60 and the left and right arms 30 are prevented from slipping with respect to the moving frame 60. The operating portion 35 can be firmly brought into sliding contact, and the straight movement of the moving frame 60 can be reliably transmitted to the rotational movement of the arm 30.
(7) Since the motor 80 and each component are disposed with the rear piece 11 of the mounting plate 10 being spaced apart, heat generated from the motor 80 is not easily transmitted to each component.

With reference to FIG. 7, a projector (home use (optical path diaphragm device) according to a second embodiment of the present invention will be described.
In the apparatus described with reference to FIG. 1 and the like, the blade 20 has a posture in which the blade 20 extends downward from the mounting plate 10, but the blade 20 may be mounted to extend upward from the mounting plate 10. In this device 1A, the blade 20 has the base 23 attached to the front surface 31b of the arm 30, and the light-shielding portion 23 is in a direction opposite to the direction in which the front and rear pieces 13, 11 of the mounting plate 10 are bent (in this example, upward). It is attached to extend.

In this case, the light source is disposed in a space above the mounting plate 10, and components such as the arm 30 and the moving frame 60 are disposed in a space below the mounting plate 10. Therefore, since these components are shielded from the light source arrangement space by the mounting plate 10, they can be protected from a high temperature environment. Also in this case, unlike the optical path opening / closing device mentioned in the conventional example, it is not necessary to form an opening or the like through which the blade passes through the base plate (mounting plate), and it is only a simple operation to attach the blade 20 in reverse.
In addition, although the attitude | position which the blade | wing 20 extends upward was demonstrated in FIG. 7, the apparatus 1A can also be mounted | worn with a projector in the upside down attitude | position.

A projector (home) optical path stop device according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a bottom view of the optical path diaphragm according to the third embodiment. FIG. 9A is a perspective view showing an optical path fully closed state, and FIG. 9B is a perspective view showing an optical path fully opened state.
In the business projector described with reference to FIG. 1 and the like, the opening / closing time of the blades is about 1 second, but in the home projector, it is preferably about 0.1 seconds. For this reason, the optical path stop device 1B of this example uses a shaft motor (linear motor) instead of the stepping motor in order to move the moving frame. Since the blade opening / closing mechanism by the moving frame and the left and right arms is the same as that of the optical path diaphragm device of FIG. 1, description thereof will be omitted, and only the arm driving mechanism will be described.

  The shaft motor 100 includes a shaft portion 103 and a coil portion 101 that is externally fitted to the shaft portion 103 in a non-contact manner. The shaft portion 103 is obtained by joining N poles and S poles of a plurality of cylindrical magnets on a shaft in a pipe. The coil portion 101 is provided with a three-phase hollow air-core coil on a sleeve. When the coil unit 101 is energized, a magnetic field is generated and a thrust is generated. The coil portion 101 moves in a non-contact manner along the shaft portion 103 by this thrust.

  The shaft portion 103 of the shaft motor 100 extends through the through hole on the left and right center of the moving frame 60 and extends on the optical axis A in the plane. The front and rear ends of the shaft portion 103 are fixed to the front piece 13 and the rear piece 11 of the mounting plate 10, respectively. The coil unit 101 is accommodated in the moving frame 60.

  When the coil portion 101 is energized, thrust is generated as described above, and the coil portion 101 moves on the shaft portion 103 by this thrust. At this time, the moving frame 60 in which the coil portion 103 is accommodated is also a guide pin. 87 will guide you forward at the same time. As the moving frame 60 advances, the left and right arms 30 rotate in opposite directions as in the apparatus shown in FIG. 1, and as a result, the blades 20 open (see FIG. 9B). When a current in the reverse direction is passed through the coil portion 101, the coil portion 101 moves backward on the shaft portion 103, and similarly, the moving frame 60 also moves backward and rotates in the direction in which the left and right arms 30 oppose each other. Close (see FIG. 9A).

  Since the shaft motor is a direct acting type (linear motor), the speed can be made faster than that of the stepping motor + screw feed mechanism, and the opening / closing time of the blades can be set to about 0.1 seconds.

A projector optical path diaphragm according to the fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a bottom view showing the optical path fully closed state, and FIG. 11 is a bottom view showing the optical path fully open state.
The optical path stop device 1C of this example differs from the first and third embodiments in the structure of the left and right arms and the blade opening / closing mechanism driven by the arms. Accordingly, the shapes of the mounting plate and the moving frame are different from those of the first and second embodiments. In this example, a shaft motor is used as a means for moving the moving frame forward as in the second embodiment. The shapes of the left and right blades are the same as in the first embodiment.

The mounting plate 10 of the device 1C is formed with left and right extensions 17 extending forward from the front ends of the left and right sides beyond the front piece 13.
Further, the moving frame 60 has substantially the same structure as the moving frame of the second embodiment corresponding to the shaft motor, but the side edge portion for sliding contact with the arm is not formed, and each of the left and right sides is not provided. A step 77 extending outward from the side edge is formed.

The arm 130 is greatly different from the structure of the arm in the embodiment of FIGS. 1 and 8, and includes a blade-side link arm 131 and a moving frame-side link arm 132 that constitute a link. Both link arms 131 and 132 are connected by a pin 133 so as to be rotatable.
One end of the blade side link arm 131 is rotatably connected to the tip of the extension portion 17 of the mounting plate 10 by a pin 141. The blade 20 is attached to the outer surface of the link arm 131. One end of the moving frame side link arm 132 is rotatably connected to the stepped portion 77 of the moving frame 60 by a pin 143.

  A coil portion of a torsion spring 151 is inserted into a pin 133 that connects both the link arms 131 and 132. One arm of the torsion spring 151 is in contact with the pin erected at the center of the blade side link arm 131 from the inside, and the other arm is erected near the center of the moving frame side link arm 132. It is in contact with the pin from the inside. That is, the link arms 131 and 132 are biased in the opening direction by the torsion spring 151.

  When the diaphragm shown in FIG. 10 is closed, the moving frame 60 is located at the most advanced position. The blade-side link arm 131 and the moving frame-side link arm 132 are bent outward with the pin 133 as the center. In other words, the blade-side link arm 131 extends in a plane that intersects the direction of the optical axis A, and the blade 20 also has a posture parallel to the direction that intersects the direction of the optical axis A, so Closed. During this time, both link arms 131 and 132 are urged in the opening direction by the torsion spring 151.

  When opening the diaphragm, the shaft motor 100 is rotated to retract the moving frame 60. Then, one end of the moving frame side link arm 131 is pulled backward by the moving frame 60, and the link arms 131 and 132 begin to rotate in the opening direction. In other words, the left and right blade side link arms 131 rotate in opposite directions around the pin 141 (the left blade side link arm 131L is clockwise and the right blade side link arm 131R is counterclockwise). When the moving frame 60 moves to the rearmost position, as shown in FIG. 11, the blade side link arm 131 rotates approximately 90 ° until it is aligned with the moving frame side link arm 132, and the left and right blades 20 are moved. Open until the direction is substantially parallel to the direction of the optical axis A.

  During the forward or backward movement of the moving frame 60, the arms 131 and 132 are biased in the opening direction by the torsion spring 151, so that play between the arms can be suppressed.

A projector optical path diaphragm according to a fifth embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 12, the optical path stop device 1D of this example is different in the structure of the arm from the first embodiment, and accordingly, the structure of the moving frame is also different. Also, the attachment method of the coil spring that absorbs the play between the female screw and the lead screw of the moving frame is different. Only differences from the apparatus of FIG. 1 will be described below.

The structure of the arm will be described with reference to FIG. In this example, the left arm is described, but the right arm has the same structure.
The arm 30 includes a base portion 31 that is rotatably supported by the mounting plate 10 and an operating portion 35 that is in sliding contact with a moving frame 60 described later. A through hole 33 penetrating in the vertical direction is formed in the vicinity of the boundary between the base portion 31 and the operating portion 35. As shown in FIG. 12, a support column 41 that supports the arm 30 is inserted into the through hole 33. One end of the support column 41 is attached by being crimped to the mounting plate 10. An E-ring is attached to the tip of the support column 41 protruding from the through hole 33 of the arm 30 via a washer. Thereby, the arm 30 is rotatably supported by the support column 41.

  The operating portion 35 of the arm 30 has an L-shaped planar shape extending from the rear portion of the base portion 31 toward the center (in the direction of the optical axis) and further extending backward (in the direction of the moving frame). A roller 38 is rotatably supported at the distal end of the operating portion 35 by a support column 39 extending in the same direction as the support column 41. Specifically, a thin upper and lower piece is formed at the tip of the operating portion 35, and a roller 38 is rotatably supported by a column 39 attached between the upper and lower pieces. The roller 38 is pushed by the moving frame 60 and the arm 30 is rotated.

The structure of the moving frame will be described with reference to FIG. 14A is a perspective view of the moving frame, and FIG. 14B is a bottom view.
The moving frame 60 in this example includes left and right block portions 61L and 61R, and a rear wall portion 64 between both block portions. A female screw 65 penetrating in the front-rear direction in parallel with the optical axis A is formed at a position of the rear wall portion 64 at the center in the left-right direction of the moving frame 60.

  Rails 79 extending in the left-right direction are formed on the front surface of the left and right block portions 61. The roller 38 of the operating portion 35 of the arm 30 is engaged with the rail 79 and rotates along the rail 79 while the moving frame 60 is moving.

  Further, as shown in FIG. 14B, a protrusion 75 is formed on the lower surface of the left and right block portions 61 so that one end of a coil spring 91 for connecting to the arm 30 is locked. The other end of each coil spring 91 is locked to the protrusions formed on the left and right arms 30, as shown in FIG. The left and right arms 30 and the moving frame 60 are pulled toward each other by the coil springs 91, and free rotation of the arms 30 is suppressed.

  Further, a protrusion 77 similar to the protrusion 75 is formed on the lower surface of the rear wall portion 64 at the center in the left-right direction of the moving frame 60. One end of a coil spring 89 that absorbs play between the female screw of the moving frame and the lead screw is locked to the protrusion 77. As shown in FIG. 12, the other end of the coil spring 89 is locked to the front piece 13 of the mounting plate 10. The coil spring 89 urges the moving frame 60 in the forward direction (the direction toward the front piece 13 of the mounting plate 10).

The optical path opening operation will be described with reference to FIGS. 15 is a diagram illustrating a fully closed state of the optical path stop device of FIG. 12, FIG. 15A is a perspective view illustrating the fully closed state, and FIG. 15B is a perspective view illustrating the fully opened state. . Since this figure is a view of the optical path stop device as seen from the back side, the horizontal direction is opposite to the horizontal direction of FIG.
When the optical path is closed, as shown in FIGS. 12 and 15A, the moving frame 60 is positioned at the rearmost side of the lead screw 83. The left and right arms 30 are biased in the direction of the moving frame 60 by the coil spring 91, and the base 23 of the left and right blades 20 is in contact with the front piece 13 of the mounting plate 10. Thereby, the light path is shielded by the light shielding portion 21 of the blade 20. A roller 38 provided at the tip of the operating portion 35 of the left and right arms 30 is engaged with a rail 79 formed on the front surface of the moving frame 60. Further, the moving frame 60 is pulled forward by a coil spring 89, thereby absorbing backlash between the lead screw 83 and the female screw 65 of the moving frame 60.

  When the stepping motor 80 is driven to rotate the lead screw 83, the moving frame 60 is guided by the guide pin 87 and moves forward along the lead screw 83. As a result, the front surface of the moving frame 60 pushes the operating portion 35 of the arm 30 forward, and the left and right arms 30 are in opposite directions centered on the column 41 (the left arm 30L is the counterclockwise direction in FIG. 30R rotates in the clockwise direction in FIG. While the moving frame 60 moves forward, each roller 38 of the arm 30 rotates along the rail 79 of the moving frame 60. At this time, since the moving frame 60 and the arm 30 are in contact with each other via the rollers 38, the contact area between the two is reduced, and the sliding resistance can be suppressed to reduce noise. Further, since each roller 38 is stably guided along the rail 79, each arm 30 can be smoothly rotated.

  When the moving frame 60 moves to the foremost position, as shown in FIG. 15B, the arm 30 is rotated by approximately 90 °, and the left and right blades 20 are opened until they are substantially parallel to the optical axis of the optical path.

DESCRIPTION OF SYMBOLS 1 Optical path diaphragm device 10 Mounting plate 11 Rear piece 13 Front piece 20 Blade 21 Light-shielding part 23 Base part 25 Bending part 26 Notch 30 Arm 31 Base part 33 Through-hole 35 Actuation part 36 Tip part 38 Roller 39 Post | support 41 Post 43 Projection part 45 Screw DESCRIPTION OF SYMBOLS 50 Drive mechanism 60 Moving frame 61 Block part 63 Front wall part 64 Rear wall part 65 Female thread 67 Boss 69 Side edge part 71 Opening part 73 Guide hole 75 Protrusion part 79 Rail 80 Stepping motor 83 Lead screw 85 Bearing 87 Guide pin 89 Coil spring 91 Coil spring

Claims (1)

A blade that rotates about a rotation axis that extends in a direction intersecting the direction of the optical axis of the optical path between a closed position that blocks the optical path of the projector and an open position that opens the optical path;
An arm for rotating the blade;
A drive mechanism for driving the arm;
With
Wherein the drive mechanism, rotates the arm, itself have a linear motion member for linear motion,
An optical path stop device for a projector , wherein the drive mechanism includes a rotation motor and a screw feed mechanism, or a shaft motor .

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