JP2004264713A - Barrier unit for optical use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an aperture diameter as much as possible by a plurality of blades in a barrier unit for shielding an optical path by moving the plurality of the blades in an iris-like form. <P>SOLUTION: A barrier unit for optical use has a plurality of blades 30 arranged in an annular form so as to be overlapped one another and a cam ring 20 for moving the plurality of the blades 30 in the iris-like form so as to shield a prescribed opening 41, and is disposed on the optical path of an optical system. In the barrier unit, a first cam groove 22 which does not make an cam action effective from a halfway of a drive stroke, and a second cam groove 23 which makes an cam action effective over the entire range, are provided with the cam ring 20 when moving the plurality of the blades 30 synchronously toward the center L of the opening 41; and the last reduction of the aperture diameter is performed by moving only a part of the blades 30 by the second cam groove 23. Consequently, the aperture diameter can be reduced as much as possible, and the light beam can be effectively shielded with a simple structure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical barrier device that opens and closes an optical path by moving a plurality of blades in an iris shape, and in particular, a digital camera, a mobile camera mounted on a portable information terminal, etc. The present invention relates to an optical barrier device that can be opened and closed.
[0002]
[Prior art]
A diaphragm device that moves a plurality of blades in an iris shape is known as a device for narrowing the optical path of a lens optical system to a desired aperture. As shown in FIG. 9, the aperture device sequentially arranges a plurality of blades 1 having the same shape and superimposes them, and drives them synchronously by a cam ring having a plurality of cam grooves having the same shape to open the opening 2. It narrows down to a desired diameter.
In this diaphragm device, the leading ends of the blades 1 cooperate to define a diaphragm opening. However, as shown in FIG. 10 (here, for convenience of explanation, three blades 1 are shown), the leading end of the blades 1 However, since it is configured to ride on one of the adjacent blades 1 and dive below the other, the blades 1 cannot approach each other more than a predetermined amount depending on the thickness, hardness, number of the blades, and the like. As shown in FIG. 9, a relatively large minimum opening remains and cannot be completely shielded.
[0003]
On the other hand, as a diaphragm device capable of completely blocking an optical path, there is known a diaphragm device in which one or several blades of a plurality of blades have different shapes and the optical path is completely blocked by blades having different shapes. (For example, see Patent Documents 1 and 2).
Further, there is a known type in which a set having a drive mechanism and a plurality of blades is arranged in a plurality of stages in the optical axis direction, and the optical path is completely shielded by the cooperation of the blades included in each stage (for example, Patent Reference 3).
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 55-11223 [Patent Document 2]
Japanese Utility Model Publication No. 55-71326 [Patent Document 3]
JP-A-56-30295
[Problems to be solved by the invention]
By the way, if the above-described aperture device is adopted as an optical barrier device that is arranged in front of an image pickup device such as a CCD to block an optical path, first, in the aperture device in which the minimum aperture remains relatively large, light rays can be effectively used. It is not preferable because it cannot be shut off.
In addition, in a diaphragm device that includes blades having different shapes in a plurality of blades, a mold or the like for forming the blades is separately required, and problems such as mis-combination are likely to occur. Is inferior in symmetry and is not preferable in terms of design.
Furthermore, the aperture mechanism in which the drive mechanism and the plurality of blades are arranged in a plurality of stages has a large structure, and is difficult to mount on a portable information terminal such as a digital camera, a mobile phone, or a portable personal computer.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a plurality of vanes arranged in an annular shape and moving in an iris-like manner, but with a simple structure, the aperture of the aperture is reduced. An object of the present invention is to provide an optical barrier device capable of minimizing the minimum aperture as much as possible and effectively blocking light rays.
[0007]
[Means for Solving the Problems]
The optical barrier device of the present invention includes a plurality of blades arranged in an annular shape so as to overlap with each other, and a drive mechanism for moving the plurality of blades in an iris shape to shield a predetermined opening. An optical barrier device disposed on an optical path, wherein the drive mechanism moves one of the plurality of blades from the middle of the drive stroke when moving the plurality of blades toward the center of the opening while synchronizing the plurality of blades. Only the blades of the part are moved.
According to this configuration, when the plurality of blades are driven by the driving mechanism so as to approach each other toward the center of the opening, all the blades move synchronously up to the middle of the drive stroke, and from the middle. At the beginning, only some of the preselected blades move further toward the center. As described above, in a region where the opening is narrowed and the aperture is reduced, only a part of the blades moves, so that the number of overlapping blades is reduced, and the blades are more likely to approach each other, and the opening is reduced as much as possible. The aperture can be reduced to a small diameter (for example, to a pinhole state), and when the thickness of the blade is thin and deformable, the opening can be shielded in a substantially fully closed state.
Therefore, the optical path can be substantially blocked to block the light beam. When this optical barrier device is arranged in front of an image pickup device such as a digital camera or a mobile camera mounted on a portable information terminal, it can prevent sunlight rays or the like. It can be effectively shut off.
[0008]
In the above configuration, the drive mechanism includes a cam ring having a plurality of cams rotatably supported around the opening and exerting a cam action on the plurality of blades, and the plurality of cams generate the cam action from the middle of the drive stroke. A configuration can be employed that includes a first cam that does not have a cam and a second cam that performs a cam action over the entire driving stroke.
According to this configuration, when the cam ring rotates in a predetermined direction, the first cam and the second cam exert a cam action on the corresponding blades, and the blades approach each other toward the center of the opening, During the middle of the drive stroke (when the cam ring rotates further after rotating by a predetermined angle), the first cam does not exert a cam action and the corresponding blade is held at that position, and the second cam continuously exerts the cam action and the corresponding blade Further approach towards the center of the opening. As a result, the opening can be easily shielded in a substantially fully closed state, or the opening can be easily narrowed down to the smallest possible diameter (for example, to the pinhole state).
Further, since the drive mechanism is formed of a cam ring having the first cam and the second cam, the structure is simple, the device can be reduced in size and thickness, and the device can be easily mounted on a digital camera, a portable information terminal, or the like. Can be.
[0009]
In the above configuration, it is possible to adopt a configuration in which the second cam is formed so as to drive some blades arranged at equal intervals in the circumferential direction of the opening.
According to this configuration, some of the blades selected to perform the final aperture operation (shielding operation) are the blades arranged in a point-symmetrical manner, so that this device is used for digital cameras, portable information terminals, and the like. When mounted at a position where it can be visually recognized, added value is also excellent in terms of design.
[0010]
In the above configuration, it is possible to adopt a configuration in which the cam ring is provided with a grip portion for manually applying a rotational force.
According to this configuration, the opening and closing or the squeezing operation can be easily performed simply by the operator grasping the grip portion and turning the cam ring, and the device is further reduced in size and simplified because of the manual operation. And cost reduction.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 8 show an embodiment of an optical barrier device according to the present invention. FIG. 1 is an exploded perspective view of the device, FIG. 2 is an external front view of the device, and FIG. FIG. 4 is a front view of a cam ring forming a driving mechanism, FIG. 5 is a front view showing a state in which a plurality of blades fully open an opening, and FIG. 6 is a diagram in which a plurality of blades move synchronously halfway through a driving stroke. 7 and 8 are front views showing a state where only some of the blades have moved. In FIG. 1, only one blade is shown for convenience.
[0012]
As shown in FIGS. 1 to 3, the apparatus is driven by an annular base 10 defining a part of an outer contour, a cam ring 20 as a driving mechanism rotatably supported by the base 10, and a cam ring 20. The plurality of blades 30 are formed by a cover 40 which supports the plurality of blades 30 so as to be swingable and defines a part of an outer contour at the same time.
[0013]
As shown in FIGS. 1 and 3, the base 10 has an annular inner wall 11 defining an opening 11 a at the center, an annular recess 12 accommodating the cam ring 20, an annular outer wall 13 forming an outer contour, and an outer wall 13. It has a notch 13a formed in part, a hook piece 14 formed integrally with the outer wall 13, and the like.
[0014]
As shown in FIGS. 1, 3, and 4, the cam ring 20 is formed in an annular shape so as to define an opening 21 at the center, and is formed as a first cam formed at substantially equal intervals along the circumferential direction. It includes one first cam groove 22, four second cam grooves 23 as second cams, a gripping portion 24 formed to project radially outward from the outer peripheral surface, and the like.
The cam ring 20 is accommodated in the concave portion 12 of the base 10, and the inner peripheral surface of the opening 21 is slidably fitted on the cylindrical surface 11 b of the inner wall 11 of the base 10, and is rotatably supported. ing.
[0015]
As shown in FIG. 4, the first cam groove 22 positions the blade 30 at the fully open position when a follower pin 32 of the blade 30 described later is at the position A, the cam ring 20 rotates clockwise, and the middle of the drive stroke. It exerts a cam action on the blade 30 to the position B, which is the position, to move the blade 30 toward the center L. Further, the cam ring 20 rotates clockwise, and the position from the position B, which is an intermediate position, to the position C. The blade 30 is formed so as not to exert a cam action on it.
The first cam groove 22 may be provided with a margin so that the follower pin 32 does not contact the groove end when the follower pin 32 is at the position C.
[0016]
As shown in FIG. 4, the second cam groove 23 positions the blade 30 at the fully open position when the follower pin 32 of the blade 30 described later is at the position A ′, the cam ring 20 rotates clockwise, and the Synchronizing with the blade 30 driven by the first cam groove 22 until the position of B ′, which is an intermediate position, exerts a cam action on the corresponding blade 30 to move the blade 30 toward the center L. 20 rotates clockwise, and further acts to further move the corresponding blade 30 toward the center L by exerting a cam action from the position B ', which is an intermediate position, to the position C'. .
The second cam groove 23 may be provided with a margin so that the follower pin 32 does not contact the groove end when the follower pin 32 is at the position C '.
[0017]
The plurality (eight in this case) of blades 30 are all formed in the same shape by a metal plate having a thickness of 0.1 mm or less, and as shown in FIGS. 1 and 3, a support shaft protruding from one surface. 31 and a follower pin 32 protruding from the other surface. Each of the blades 30 has a support shaft 31 inserted into a bearing hole 42 of a cover 40 described later to be swingably supported, and a follower pin 32 is inserted into the first cam groove 22 or the second cam groove 23 to perform a cam action. Has been affected.
[0018]
As shown in FIGS. 5 to 8, the plurality of blades 30 are arranged in an annular shape so as to overlap with each other along the cam ring 20, and the distal end regions thereof are adjacent to each other as shown in FIG. The cam ring 20 rotates, so that the entire blade 30 moves in an iris-like manner, and opens or closes the opening or opens a desired opening. It works to narrow down the aperture.
[0019]
As shown in FIGS. 1 to 3, the cover 40 is formed in an annular shape so as to define an opening 41 at the center, and has eight bearing holes 42 and blades 30 formed at equal intervals in the circumferential direction inside the cover 40. A recess 43 defining a blade chamber to be housed, an outer wall 44 forming an outer contour, a notch 44 a formed in a part of the outer wall 44, a retaining recess 45 formed in the outer wall 44, and the like are provided.
[0020]
The procedure for assembling this device will be briefly described. As shown in FIG. 1, when each component is prepared, first, the cam ring 20 is housed in the concave portion 12 of the base 10 and rotatably supported. At this time, the holding portion 24 is attached so as to fit into the notch 13a.
Next, the support shafts 31 of the respective blades 30 are inserted into the bearing holes 42 of the cover 40 to support the plurality of blades 30 in a swingable manner, and then the follower pins 32 are connected to the corresponding first cam grooves 22 or second cams. The cover 40 is connected to the base 10 so as to be inserted into the respective grooves 23. At this time, the notch 44a is attached so as to face the notch 13a so as to movably accommodate the grip portion 24.
Also, the cover 40 and the base 10 are easily connected by snap-fitting the latching pieces 14 to the latching recesses 45. When connecting the two, a fastening screw or the like may be used instead of the hook piece 14 and the hook recess 45.
[0021]
As a result, the cam ring 20 is rotated by gripping the grip portion 24, and the rotation of the cam ring 20 causes the plurality of blades 30 to move in an iris shape to open or close or narrow the openings 41, 11a. . Here, the rotation range (drive stroke) of the cam ring 20 is regulated by the gripping portions 24 abutting on both ends of the notches 13a and 44a.
As described above, since this optical barrier device has a simple structure and can be easily assembled, the device can be made thinner, smaller, and lower in cost, and can be used in digital cameras, portable information terminals, and the like. It can be easily mounted.
[0022]
Next, the operation of this device will be described with reference to FIGS.
First, when the cam ring 20 is located at the counterclockwise rotation end, as shown in FIG. 5, the plurality of blades 30 are in a state where the openings 41 (11a, 21) are fully opened.
In this state, when the operator grips the grip portion 24 and rotates the cam ring 20 clockwise, the cam action of the first cam groove 22 and the second cam groove 23 causes all (eight) blades 30 to open. It moves synchronously so as to approach each other toward the center L of the portion 41 (11a, 21), and reaches the position shown in FIG. This state corresponds to a state where the minimum aperture remains in the conventional diaphragm device.
[0023]
Subsequently, when the operator further rotates the cam ring 20 clockwise beyond the intermediate position of the driving stroke, the first cam groove 22 does not exert a cam action, and only the second cam groove 23 exerts a cam action. . That is, as shown in FIG. 7, only the four blades 30 driven by the second cam grooves 23 approach each other further toward the center L, and further narrow the opening 41 (11a, 21).
[0024]
Subsequently, when the operator rotates the cam ring 20 clockwise until the gripper 24 comes into contact with the ends of the notches 13a and 44a, the four blades 30 are further rotated by the cam action of the second cam groove 23. 8, the aperture 41 (11a, 21) is narrowed down to a pinhole state as shown in FIG. In this state, the state is almost the same as the fully closed state where the light beam can be almost blocked.
[0025]
As described above, in the driving stroke after the state shown in FIG. 6, only a part (four) of the eight blades 30 are moved, so that the pinhole shown in FIG. The aperture 41 (11a, 21) can be narrowed down to the state.
It is preferable that the opening 41 (11a, 21) be narrowed as small as possible (or fully closed) as long as it is used as a barrier device for completely blocking the light beam. The size of the minimum opening can be appropriately adjusted by appropriately selecting the number of the 30 sheets.
[0026]
As shown in FIGS. 6 to 8, the blade 30 that performs the final narrowing, that is, the blade 30 that is driven by the second cam groove 23, is approximately 90 in the circumferential direction of the opening 44 (11 a, 21). Since the four blades 30 located at positions equidistant from each other are applied, the operation of the blades 30 is point-symmetric, and in the state shown in FIG. 7 and FIG. Fits all forms.
Therefore, when this device is mounted on a digital camera, a portable information terminal, or the like, and is disposed at a position visible inside a lens, a transparent plate, or the like, an added value excellent in design can be obtained.
[0027]
In the above-described embodiment, eight blades are shown as the plurality of blades 30. However, the number of blades is not limited to eight, and a configuration in which seven or less blades or nine or more blades are employed may be used. The invention may be applied.
Further, in the above embodiment, the configuration in which the support shaft 31 is provided on one surface of the blade 30 and the follower pin 32 is provided on the other surface has been described. However, as long as interference between the blade 30 and the support shaft 31 or the follower pin 32 can be prevented. Alternatively, a configuration in which a support shaft and a follower pin are provided on the same surface may be adopted.
[0028]
In addition, the cam ring 20 having the first cam groove 22 and the second cam groove 23 formed in a groove shape is shown as the drive mechanism and the first cam and the second cam. If so, the configuration is not limited to the groove shape and is not limited to the ring shape, and other configurations may be adopted.
Further, in the above-described embodiment, this device is applied as a barrier mechanism that is disposed on the optical path of the optical system and shields the opening, but may be applied as a diaphragm device that narrows the opening to a desired diameter.
[0029]
【The invention's effect】
As described above, according to the optical barrier device of the present invention, when moving a plurality of blades arranged annularly so as to overlap each other toward the center of the opening while synchronizing, Thus, by employing a drive mechanism that moves only some of the blades, the aperture diameter of the aperture can be reduced as much as possible. Therefore, the optical path can be substantially blocked to block the light beam. When this optical barrier device is arranged in front of an image pickup device such as a digital camera or a mobile camera mounted on a portable information terminal, it can prevent sunlight rays or the like. It can be effectively shut off. Also, by using vanes arranged at equal intervals as vanes for performing the final narrowing down, the vanes move point-symmetrically, so that this device can be placed in a position that can be visually recognized by digital cameras, portable information terminals, etc. When it is installed, excellent added value in terms of design can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of an optical barrier device according to the present invention.
FIG. 2 is a front view showing an embodiment of the optical barrier device according to the present invention.
FIG. 3 is a partial sectional view showing an embodiment of the optical barrier device according to the present invention.
FIG. 4 is a front view showing a cam ring as a driving mechanism.
FIG. 5 is a front view showing a relationship between a cam ring and a plurality of blades, in a state where the blades are fully opened.
FIG. 6 is a front view showing a relationship between a cam ring and a plurality of blades, and showing a throttle state of the blades when the cam ring rotates halfway through a driving stroke.
FIG. 7 is a front view showing a relationship between a cam ring and a plurality of blades, showing a throttle state in which the cam ring has rotated beyond a predetermined angle and only some of the blades have moved further.
FIG. 8 is a front view showing a relationship between a cam ring and a plurality of blades, showing a state in which only some of the blades are further moved and narrowed down into a pinhole shape.
FIG. 9 is a front view showing a conventional diaphragm device.
FIG. 10 is a perspective configuration diagram for explaining the mutual relationship of blades in a conventional diaphragm device.
[Explanation of symbols]
Reference Signs List 10 Base 11 Inner wall 11a Opening 12 Recess 13 Outer wall 13a Notch 14 Hook 20 Cam ring (drive mechanism)
21 Opening 22 First cam groove (first cam)
23 2nd cam groove (2nd cam)
24 Gripping part 30 Plural blades 31 Support shaft 32 Follower pin 40 Cover 41 Opening 42 Bearing hole 43 Recess 44 Outer wall 44a Notch 45 Latch recess B, B 'Halfway position L of drive stroke L Center of opening

Claims (4)

A plurality of blades arranged in an annular shape so as to overlap each other, and a drive mechanism for moving the plurality of blades in an iris shape so as to block a predetermined opening, for an optical device arranged on an optical path of an optical system A barrier device,
The drive mechanism, when moving toward the center of the opening while synchronizing the plurality of blades, from the middle of the drive stroke, to move only some of the plurality of blades,
An optical barrier device, comprising: The drive mechanism includes a cam ring having a plurality of cams rotatably supported around the opening and acting on the plurality of blades,
2. The plurality of cams according to claim 1, wherein the plurality of cams include a first cam that does not generate a cam action in the middle of the drive stroke, and a second cam that performs a cam action throughout the drive stroke. 3. Optical barrier device. The second cam is formed so as to drive some of the blades arranged at equal intervals in a circumferential direction of the opening.
The optical barrier device according to claim 2, wherein: The cam ring is provided with a gripper for manually applying a rotational force.
The optical barrier device according to claim 2 or 3, wherein:

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