JP5091621B2 - Optical path stop / opening / closing device - Google Patents

Description

  The present invention relates to an optical path stop / opening / closing device used as a shutter or an iris of a small camera or the like.

  In a typical type of such an optical path stop / opening / closing device, two blade members are slid on the base by an actuator-driven arm. As the blade member slides on the base, the opening formed in the base is narrowed or opened and closed.

8A and 8B are diagrams illustrating an example of the shape of the arm, in which FIG. 8A is a perspective view, FIG. 8B is a plan view, and FIG. 8C is an enlarged view of a boss portion.
FIG. 9 is a side view showing an assembled state in which a blade member is engaged with the arm of FIG.
As shown in FIG. 8, a boss portion 122 is erected at the center of the base portion 121 of the arm 120, and the rotation shaft of the actuator is fitted and fixed to the boss portion 122. Engagement pins 123 that engage with the engagement holes of the blades are provided upright at both ends of the base portion 121. Each engagement pin 123 has a base part 123a having a large diameter and a tip part 123b having a small diameter, and a blade pressing part 123c having a diameter larger than that of the tip part 123b is provided at the tip of the tip part 123b. As shown in FIG. 8, the engagement hole of the blade is engaged with the small diameter tip portion 123b, and the blade is supported by the blade pressing portion 123c so as not to come off from the engagement pin 123.

  When forming the arm 120 having such a shape, generally, as shown in FIG. 8B, a plane center line of the arm 120 (a line passing through the centers of the engagement pins 123 and the boss portion 122) is used as a party. A fixed mold and a movable mold formed by dividing the arm center (the boss part 122 periphery) in the direction of the center hole as a ring line (PL), jumping into the vertical direction, and halving the periphery of the engagement pin 123 It is formed by a moving mold and a fixed mold to be formed (also called a slide mold). In this case, both molds are fitted on the side surface of the engagement pin 123, and burrs are generated at the mold dividing portion on the same side surface. Further, when the dimensional accuracy of the mold of this method is particularly bad, as shown in FIG. 8C, there may be a situation in which the radius is different between the lateral half of the engagement pin 123 and the other half. Furthermore, it is expensive because of the complicated mold structure.

  If there is a burr on the side surface of the engagement pin, the blade member does not rotate smoothly along the engagement pin, and the sliding operation is not smooth. Further, if the radius is different between one side and the other half of the engaging pin, the moving amount of the blades is different. As a result, the opening accuracy may deteriorate.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an optical path stop / opening / closing device that can further improve the opening accuracy.

Optical path aperture-closing device according to the first embodiment as the base of the present invention, an actuator, an arm which is rotated by the actuator, is slidably driven by the arm, and the blade for opening and closing or narrowing the optical aperture, An optical path stop / opening / closing device having a base that guides the blade and having an optical path opening, wherein an engagement pin that engages the blade is formed on the arm, and at a portion different from the engagement pin A hook having a blade pressing portion for preventing the blade from being detached from the base is formed.

  The dimensional accuracy of the engaging pin can be increased by forming the pressing portion of the blade on a separate hook instead of the engaging pin of the arm with which the blade engages. That is, when an engagement pin having a blade pressing portion formed at the tip is produced, the arm is formed by a half-cut mold, so that a burr is generated at the mold split portion on the side surface of the engagement pin. However, when the hook for holding the blade is provided separately from the engagement pin as in the present invention, and the engagement pin has a shape without an undercut portion, the engagement pin is made of a cylindrical hole of one mold. And the roundness of the engagement pin is increased. Therefore, the movement of the blades becomes smooth and the accuracy of the opening is improved.

  In the present invention, if the blade pressing portion protrudes in a substantially right angle direction of the rotation axis of the arm and the portion of the arm facing the blade pressing portion is a punched hole or notch, The structure can be simplified and can be manufactured at low cost.

When forming an arm having a blade pressing portion having such a shape, an engagement pin and a hook are formed on the fixed mold, and the other part is formed on the movable mold. And since the undercut part of the blade | wing press part of a hook is formed in a movable metal mold | die, the through hole of those undercut parts is formed in the part facing the blade | wing press part of an arm.
It should be noted that the arm having such a shape can be used as a complicated mold structure (a slide mold in which the movable mold jumps from the vertical direction in addition to the fixed / movable mold) without providing a punched hole or notch. Can be produced. However, by providing a through hole or notch, a slide mold becomes unnecessary, and the mold can be formed with a simple and inexpensive mold structure.

In the present invention, it is preferable that the lower surface of the blade pressing portion of the hook is slightly convexly curved.
Depending on the posture of the device, the blade may contact the lower surface of the blade pressing portion. Therefore, by curving the lower surface of the blade pressing portion slightly convex, the contact resistance between the blade and the blade pressing portion is reduced, and the sliding operation of the blade becomes smooth.

An optical path stop / opening / closing device according to a second embodiment related to the present invention includes: an actuator; an arm that is rotationally driven by the actuator; a blade that is slid and driven by the arm; An optical path stop / opening / closing device comprising: a base that guides a blade and having an optical path opening; and a return spring of the arm, wherein the base or the arm has a plurality of engaging portions with which one end of the return spring is engaged. It is provided.

  The return spring is very small, and the wire diameter is slightly different depending on the production lot of the spring wire, and the spring constant may vary. Therefore, by making it possible to select the position of the engaging portion at the end of the return spring, the spring force can be adjusted by changing the deflection angle of the spring.

In the present invention, the arm is provided with the return spring pressing portion that protrudes in a substantially right angle direction from the rotation axis of the arm, and the portion of the arm that faces the spring pressing portion has a punch hole or a notch. It is preferable that
Since this spring pressing portion is also produced in the same manner as the above-described hook pressing portion of the hook, a through hole of the undercut portion is formed in a portion of the arm facing the spring pressing portion.

  Furthermore, in the present invention, the hook is formed with an engaging protrusion that engages with one end of the return spring, and the engaging protrusion protrudes in a direction substantially perpendicular to the rotation axis of the arm, and It is preferable that the portion of the arm facing the engaging protrusion is a hole or a notch.

  Since this engaging protrusion is also produced in the same manner as the above-described hook pressing portion of the hook, a through hole of the undercut portion is formed in a portion of the arm facing the spring pressing portion.

An optical path stop / opening / closing device according to a third aspect related to the present invention includes: an actuator; an arm that is rotationally driven by the actuator; a blade that is slidably driven by the arm; An optical path stop / opening / closing device comprising a base having an optical path opening and a return spring of the arm, wherein the arm has a blade pressing portion for preventing the blade from being detached from the base. A plurality of engaging protrusions that engage with one end of the return spring are formed on the hook, and the engaging protrusions project in a direction substantially perpendicular to the rotation axis of the arm; A portion of the arm facing the engaging protrusion is a punched hole or notch.

  As is apparent from the above description, according to the present invention, the engagement pin of the arm that drives the blade member can have a perfect circular cross-sectional shape without burrs, so that the sliding motion of the blade member becomes smooth and the opening Accuracy can be improved. Furthermore, since it is not necessary to use a slide mold, a simpler and cheaper mold structure can be selected.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1A and 1B are diagrams showing the structure of an arm of an optical path opening / closing / aperture device according to an embodiment of the present invention. FIG. 1A is a perspective view and FIG. 1B is a side view.
2A and 2B are diagrams showing the overall configuration of the optical path stop / opening / closing device according to the embodiment of the present invention. FIG. 2A is a front view, FIG. 2B is a side view, and FIG. Is a back view.
FIG. 3 is a perspective view of the optical path stop / opening / closing device of FIG.
4 is a cross-sectional view of the optical path stop / opening / closing device of FIG.
FIG. 5 is an enlarged front view of a part of the optical path stop / opening / closing device of FIG.

First, the overall configuration of the optical path stop / opening / closing device will be described with reference to FIGS.
The optical path stop / opening / closing device 1 has a base 10 in which an optical path opening 11 is formed. On the base 10, a motor (actuator) 3, an arm 20 driven to rotate by the motor 3, and a set driven to slide by the arm 20. A return spring 5 that biases the matching blade 30 and the arm 20 to an initial position (position where the combined blade closes the optical path opening) is provided. The combination blade 30 is slid and driven by the arm 20 to narrow down or open / close the optical path opening 11.

  As shown in FIGS. 2A and 3, a flat and smooth slide surface 12 on which the combination blade 30 slides and a recess 13 to which the arm 20 is attached are provided on the surface side of the base 10. . An optical path opening 11 is opened near the center of the slide surface 12. Further, two guide pins 14 that are separated in the sliding direction are provided on both sides of the sliding surface 12. At the tip of the guide pin 14, a blade pressing portion 14a protruding in a substantially right angle direction of the pin is formed.

  The motor 3 is attached to the back surface of the recess 13, and the rotation shaft projects through the base 10 to the front side. The rotation shaft is fitted and fixed to a boss portion of an arm 20 described later. Around the boss portion, a plurality of (three in this example) spring end engaging portions 15 are erected side by side in the circumferential direction.

The combination blade 30 is composed of two blade members 31 and 32 that are vertically overlapped. On the upper side of the blade member 31, which can open the substantially circular aperture formed holes 31a in the vicinity of the center, on the lower side of the blade member 32, it is substantially arcuate aperture forming edge 32a (see FIG. 2 (A)) Is formed. Both blade members 31 and 32 are slid in the opposite direction by the arm 20, and an aperture centering on the optical axis of the optical path aperture 11 is formed by the aperture forming hole 31 a and the aperture forming edge 32 a. Engagement long holes 31b and 32b are formed in the end portions of the blade members 31 and 32, respectively. In addition, one or two cam holes 31c and 32c extending in the sliding direction are formed on both sides side by side in the sliding direction. The guide pins 14 erected on the base 10 are engaged with the cam holes 31c and 32c.

  The blade members 31 and 32 are thin members, and are made of, for example, a resin film (a polyester film as an example) that has been coated with a light shielding ability. An ND filter may be attached along the aperture forming hole 31a and the aperture forming edge 32a. By attaching such an ND filter, it is not necessary to mechanically reduce the aperture to a small diameter when adjusting the amount of light within a small range.

Next, the arm 20 will be described with reference to FIG.
The arm 20 has a substantially oval base 21. A boss portion 22 (arm rotation shaft) to which the rotation shaft of the motor 3 is fitted and fixed is erected at the center of the base portion 21, and the engagement elongated holes 31 b of the blade members 31 and 32 are provided at both ends. , 32b is erected.

The base portion of the return spring 5 is fitted to the boss portion 22. On the upper end surface of the boss portion 22, a spring pressing portion 22 a that protrudes in a substantially right angle direction of the same portion is formed to prevent the return spring 5 from coming off. In this example, three spring pressing portions 22a are formed at equal intervals in the circumferential direction.
Each engagement pin 23 has a large-diameter base portion 23a and a small-diameter tip portion 23b. Here, each part 23a, 23b of the engaging pin is a circular cylinder with a perfect cross section, and unlike the conventional engaging pin 123 described with reference to FIG. 6, no blade pressing part is provided at the tip. .

  Further, a hook 24 is erected on the base portion 21 between the boss portion 22 and each engagement pin 23. The hook 24 has an L-shape, and includes an upright portion 24a extending in the arm rotation axis direction, and a blade pressing portion 24b protruding from the tip of the upright portion 24a toward the engagement pin 23 in a substantially right angle direction. The lower surface (surface on the base portion side) of the blade pressing portion 24b is convexly curved (the central portion in the width direction protrudes downward).

  As shown in FIG. 4, each blade member 31, 32 has an engagement long hole 31 b, 32 b that engages with a small-diameter tip portion 23 b of each engagement pin 23 of the arm 20. Is riding. At this time, since the blade members 31 and 32 are pressed by the blade pressing portion 24 b of the hook 24 and the blade pressing portion 14 a of the guide pin 14 erected on the slide surface 12, the blade members 31 and 32 do not depend on the posture of the base 10. The engagement pin 23 does not come off. Further, in the posture in which the base 10 is directed downward, the blade members 31 and 32 are in contact with the lower surface (the upper surface in this posture) of the blade pressing portion 24b. Since the lower surface of the blade pressing portion 24b is slightly convexly curved, the contact resistance between the blade members 31, 32 and the blade pressing portion 24b can be reduced even in this posture. When the blade members 31 and 32 and the arm 20 are assembled, the blade members 31 and 32 are made of a thin resin film, so that the blade members are bent and assembled.

  As will be described later with reference to FIG. 1 and FIG. 5, a spring engaging protrusion 25 that engages with the other end of the return spring 5 is provided on the upright portion 24 b of one hook 24. The spring engaging protrusion 25 protrudes from the upright portion 24a in a direction substantially perpendicular to the arm rotation axis.

  As described above, the spring pressing portions 22a formed on the upper end surface of the boss portion 22, the blade pressing portions 24b of the hooks 24, and the spring engagement protrusions 25 are substantially perpendicular to the arm rotation shaft (boss portion 22). It protrudes. And the base part 21 which opposes this spring holding | suppressing part 22a and the blade | wing holding | maintenance part 24b is the punching holes C1 and C2, and the base part 21 which opposes the spring engagement protrusion 25 is notch C3. This is due to the following reason. When manufacturing the arm 20 having such a shape, generally, as shown in FIG. 1B, the upper surface of the base portion 21 of the arm 20 is PL, and a fixed mold and a movable mold for dividing the arm 20 are used. Is used. In this case, the boss part 22, each engagement pin 23, and each hook 24 are formed in a fixed mold, and the base part 21 is formed in a movable mold. Since the undercut portions of the spring pressing portion 22a, the blade pressing portion 24b, and the spring engagement protrusion 25 are formed in the movable mold, the base portion 21 is formed with a through hole or a notch in the undercut portion.

  By such a manufacturing method, the entire outer periphery of the engagement pin 23 is formed by the molding hole of the fixed mold. For this reason, the roundness of the engagement pin 23 can be easily obtained. In the case of the manufacturing method shown in FIG. 7, burrs or the like are generated in the parting portion on the side surface of the engaging pin. In this example, this is not the case, and the engaging pin 23 can be manufactured with high accuracy. it can.

  As shown in FIG. 5, the base portion 5a of the return spring 5 is fitted to the boss portion 22 of the arm 20 and is prevented from coming off by the spring pressing portion 22a. One end 5b of the return spring 5 is engaged with the spring engaging protrusion 25 of the arm 20, and the other end 5c is one of a plurality of spring end engaging portions 15 erected on the base 10 (in this example, the central one). ) Is engaged.

  The arm 20 is urged to the initial position (optical path opening fully closed position, see FIG. 2A) by the return spring 5. Depending on the production lot of the spring wire of the return spring 5, the diameter of the spring wire varies, and the spring constant may vary. Therefore, the force of the spring 5 can be adjusted by changing the deflection angle of the spring 5 by selecting a plurality of spring end engaging portions 15 erected on the base 10.

Next, the opening / closing operation | movement of a combination blade | wing is demonstrated with reference to FIG.
6A and 6B are diagrams showing the open / close state of the optical path opening of the optical path opening / closing / throttle device. FIG. 6A shows the optical path opening fully closed, and FIG. 6B shows the optical path opening fully open.
When the optical path opening is fully closed as shown in FIG. 6A, the upper blade member 31 slides to the upper slide limit, the lower blade member 32 slides to the lower slide limit, and the optical path opening 11 is completely closed. When the arm 20 is driven counterclockwise by being driven by the motor 3, the upper blade member 31 is pushed by the arm 20 and slides downward on the slide surface 12 while being guided by the guide pin 14. On the other hand, the lower blade member 32 is pulled by the arm 20 and slides upward on the slide surface 12 while being guided by the guide pin 14. As a result, an aperture around the center of the optical path aperture 11 is formed by the aperture forming hole 31a and the aperture forming edge 32a of each blade member 31, 32. When the upper blade member 31 slides to the lower slide limit and the lower blade member 32 slides to the upper slide limit, the optical path opening 11 is fully opened as shown in FIG.

  When the blade members 31 and 32 slide in this way, the engagement pins 23 of the arm 20 are made with high roundness as described above, so that the movement of the blade members 31 and 32 becomes smooth and the opening is opened. Increases accuracy.

7A and 7B are diagrams showing the structure of an arm of an optical path opening / closing and diaphragm device according to another example of the embodiment of the present invention. FIG. 7A is a perspective view and FIG. 7B is a plan view. .
In the optical path opening / closing / throttle device of FIG. 1, the base 10 is provided with a plurality of engaging portions 15 with which the end portions of the return springs 5 are engaged, but in this example, a plurality (four in this example) are provided on the arm 20 side. ) Is provided.

  Of the four engagement protrusions 25, two engagement protrusions 25A are provided so as to protrude from the vicinity of the center height of the upright portion 24b of the hook 24 in a direction substantially perpendicular to the arm rotation shaft. The base portion 21 facing these engagement protrusions 25A is a notch C4. As described above, this is for removal of an undercut portion during molding using a mold.

The remaining two engaging protrusions 25 </ b> B are erected on the outer edge near the center of the base portion 21. The engagement protrusion 25B has an L-shape and includes an upright portion extending in the arm rotation axis direction and a spring pressing portion protruding from the tip of the upright portion in a direction substantially perpendicular to the arm rotation axis.
In this way, when the plurality of spring engagement protrusions 25 are provided on the arm 20 side, one spring engagement portion 15 may be provided on the base 10.

It is a figure which shows the structure of the arm of the optical path opening / closing and diaphragm | throttle device which concerns on embodiment of this invention, FIG. 1 (A) is a perspective view, FIG.1 (B) is a side view. It is a figure which shows the whole structure of the optical-path aperture_opening / closing apparatus which concerns on embodiment of this invention, FIG. 2 (A) is a front view, FIG.2 (B) is a side view, FIG.2 (C) is a back view. is there. FIG. 3 is a perspective view of the optical path stop / opening / closing device of FIG. 2. FIG. 3 is a cross-sectional view of the optical path stop / opening / closing device of FIG. 2. FIG. 3 is an enlarged front view of a part of the optical path stop / opening / closing device of FIG. 2. It is a figure which shows the opening-and-closing state of the optical-path opening of an optical-path opening-closing and diaphragm | throttle device, FIG. 6 (A) shows the time of optical path opening fully closed, and FIG. 6 (B) shows the time of optical path opening full-open. FIG. 7A is a perspective view, and FIG. 7B is a plan view, illustrating a structure of an arm of an optical path opening / closing / throttle device according to another example of the embodiment of the present invention. It is a figure which shows an example of the shape of an arm, FIG. 8 (A) is a perspective view, FIG.8 (B) is a top view, FIG.8 (C) is an enlarged view of a boss | hub part. It is a side view which shows the assembly state in which the blade | wing member is engaging with the arm of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical path aperture / opening-closing apparatus 3 Motor 5 Return spring 10 Base 11 Optical path opening 12 Slide surface 13 Recess 14 Guide pin 15 Spring end engaging part 20 Arm 21 Base part 22 Boss part 23 Engaging pin 24 Hook 25 Spring engaging protrusion 30 Combination blade 31, 32 Blade member

Claims (2)

An actuator,
An arm that is rotationally driven by the actuator;
A blade that is slid and driven by the arm to squeeze or open or close the optical path opening;
A base for guiding the blades and having an optical path opening;
An optical path stop / opening / closing device comprising:
The base is provided with a plurality of guide pins on which the blade pressing portion is formed and guides the slide driving of the blade.
In the arm ,
The boss which is the rotation axis,
An engagement pin that engages with the blade ; and
An optical path stop / opening / closing device, characterized in that a hook having a blade pressing portion that is provided between the boss portion and the engagement pin and prevents the blade from coming off the base is formed. Optical path aperture, switchgear that claim 1 Symbol mounting, characterized in that the lower surface of the blade support portion is curved slightly convex of the hook.

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