JP2006018019A - Light quantity adjusting device, imaging apparatus, and optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light quantity adjusting device designed so that the drive of a plurality of vanes with efficient power of a drive source is achieved by a simple configuration and with less space. <P>SOLUTION: The light quantity adjusting device includes: a first vane group driven by the drive source such as a motor; and a second vane group engaged with the first vanes and moved following the movement of the first vanes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light amount adjusting device mounted on an imaging device such as a camera or a video camera, and more particularly to a light amount adjusting device capable of operating a plurality of aperture blades with one drive source for one optical path.

  As a conventional diaphragm device used for an imaging device such as a camera or a video camera, for example, a plurality of diaphragm blades having a rotation shaft and an operation shaft, and a diaphragm ring having a cam groove and a central opening, the operation of the blades There is known one in which a shaft is engaged with a cam groove and a plurality of diaphragm blades are simultaneously operated by rotating a diaphragm ring (see, for example, Patent Document 1).

  Further, the diaphragm ring is eliminated, and each of the plurality of blades is provided with a cam groove and a cam groove engaging pin, and the cam groove engaging pin of each diaphragm blade is slidably engaged with the cam groove of the adjacent diaphragm blade, A diaphragm device has been proposed in which a plurality of diaphragm blades are sequentially driven by a driving force transmitted from a driving member to one diaphragm blade (see, for example, Patent Document 2).

Further, as used in a video camera or the like with a built-in CCD, an ND filter is bonded to a part of the diaphragm blades, and when the diaphragm aperture formed by the diaphragm blades is less than a certain size, A diaphragm device using an exposure structure in which an ND filter is inserted is proposed (for example, see Patent Document 3). If the image sensor used in the image pickup unit is relatively small, if the aperture diameter is reduced too much, the captured image will be adversely affected by diffraction. The configuration is such that it does not have to be smaller than the value.
JP-A-6-175194 JP-A-6-95204 JP 2000-155352 A

  When a plurality of blades are linked by the aperture ring, there is a problem that the drive source and the aperture ring, the aperture ring and the blade are loose, and the transmission loss of the driving force due to friction generated in the cam groove of the aperture ring becomes large. there were. In addition, the configuration in which a plurality of blades in which the diaphragm blades are sequentially connected operates a problem that the backlash of the fitting portion between the blades accumulates and the aperture diameter accuracy deteriorates.

  Further, the diaphragm device provided with the ND filter has a problem that a dedicated electromagnetic drive source is required to control the ND filter independently, and the device becomes large and expensive.

  Therefore, it has been proposed that the blade including the ND filter is operated by the diaphragm ring in the same manner as the diaphragm blade. However, the driving force due to the friction between the diaphragm ring and the blade including the ND filter or the friction generated in the cam groove is proposed. There was a problem of large transmission loss.

  Further, as a matter of course, there is a problem that the entire apparatus becomes thick by using the aperture ring, and there is a problem that the cost of parts of the aperture ring is increased.

  In order to solve the above-mentioned problems, the present invention includes a fitting portion of a member having an opening, a first blade member driven by a driving source, and a first blade member, and the movement of the first blade member A second blade member that moves following the movement of the first and second blade members by superimposing the first blade member and the second blade member on the opening by driving the drive source stepwise. Provided is a light amount adjusting device that adjusts in stages.

  Similarly, in order to solve the above-described problem, the present invention includes a fitting portion that includes a member having an opening, a first blade member driven by a driving source, and a first blade member. A light amount that has a plurality of second blade members that move following the movement of the member, and adjusts the amount of light that passes through the opening portion by superimposing the first blade member and the plurality of second blade members on the opening portion. Provide a regulating device.

  Similarly, in order to solve the above problems, the present invention includes a fitting portion between a first blade member driven by a driving source and the first blade member, and follows the movement of the first blade member. The first blade member and the second blade member have a moving second blade member, and one of the first blade member and the second blade member acts as a diaphragm blade member that forms an opening whose size changes, and the other is formed by the diaphragm blade member. A light amount adjusting device is provided which acts as a filter for adjusting the amount of light passing through the opening.

  Similarly, in order to solve the above problems, an imaging apparatus and an optical apparatus provided with the above-described light amount adjusting device are provided.

  According to the present invention, since complicated mechanism parts such as a diaphragm ring are not provided, the configuration is simplified, and the blade member can be operated while suppressing transmission loss of driving force.

  In addition, a plurality of blade members having different functions such as a diaphragm blade and an ND filter can be operated by a single drive source.

  The light amount adjusting device according to the present invention is disposed on the optical path of an image pickup apparatus such as a camera or a video camera, and is used to adjust the amount of light incident on an image pickup element that receives subject light and forms an image signal. Further, it is mounted on an optical device having a lens barrel that can be attached to the imaging device, and is also used to adjust the amount of light passing through the optical device. Hereinafter, the present invention will be described in detail with reference to the drawings and preferred embodiments.

(First embodiment)
FIG. 1 and FIG. 2 are diagrams showing the operation of the light amount adjusting device in the first embodiment.

  1A is a top view of the light amount adjusting device when the aperture diameter of the diaphragm blades is maximized, FIG. 1B is a top view of the light amount adjusting device when the aperture is started, and FIG. 1C is FIG. FIG. 1D is a top view of the light amount adjusting device when the aperture is further reduced as compared with (b), and FIG. 1D is a top view of the light amount adjusting device when the aperture is minimized. FIG. 2 is a perspective view of the light amount adjusting device when the aperture diameter of the diaphragm blades is maximized.

  An electromagnetic drive source 140 such as a stepping motor is disposed on one side with a diaphragm base plate 110 having an opening at the center, and first blade groups 121 and 122 and second blade groups 131 and 132 are disposed on the other side. The overlapping order of the blades is the blade 132, the blade 122, the blade 121, and the blade 131 from the main plate side. Further, a cover plate (not shown) is overlapped with the blade 131, and the blade 121, Space for traveling 122, 131, 132 is secured.

  The blades 121, 122, 131, and 132 are disposed so as to be rotatable with respect to the main plate 110 with the support pins 121b, 122b, 131b, and 132b as axes. The support pins 121b and 122b of the first blade group and the support pins 131b and 132b of the second blade group are provided on opposite sides of the opening of the main plate 110.

  A drive lever 141 is connected to the electromagnetic drive source 140, and a tip of the drive lever 141 passes through a long hole provided in the main plate 110 and fits into a long hole provided in the first blade group 121, 122. ing. The drive lever 141 reciprocates between the support pin 121b and the support pin 122b. When the drive lever 141 moves toward the center of the main plate 110, the blade 121 and the blade 122 rotate, and the blades 121 and 122 are rotated. , 131, 132, the opening diameter formed by the inner edges becomes smaller.

  The first blade groups 121 and 122 are made of plastic, and engaging pins 121a and 122a are integrally provided, respectively. The engaging pin 122a has a convex shape toward the main plate 110, and the groove 111 provided on the main plate 110 serves as a relief groove for the engaging pin 122a. The engaging pin 121a has a convex shape in the opposite direction to the base plate side, and a cover plate (not shown) is provided with a relief groove similar to the groove portion 111 of the base plate 110.

  As shown in FIG. 1A, elastic members 151 and 152 such as springs having a biasing force in the direction in which the blades open are hung on the second blade groups 131 and 132, respectively. Edge 131a and outer edge 132a of blade 132 are in contact with engagement pins 121a and 122a of first blade group 121 and 122, respectively.

  When the electromagnetic drive source 140 is energized and the drive lever 141 rotates counterclockwise (driven toward the center of the main plate 110), the first blade group 121, 122 starts moving in the direction of narrowing and the engagement pins 121a, 122a. The second blade groups 131 and 132 that are always in contact with each other by the elastic members 151 and 152 also start to move in the direction of narrowing against the urging force of the elastic members 151 and 152. When the drive lever 141 rotates clockwise (drives away from the center of the main plate 110), the first blade group 121, 122 starts to move in the opening direction, and the second blade portions 131, 132 are also elastic members 151, The urging force of 152 moves in the opening direction while being in contact with the engagement pins 121a and 122a.

  Thus, the first blade group 121, 122 is driven by always applying the elastic member force in the opening direction to the second blade group 131, 132 and bringing it into contact with the first blade group 121, 122. Following this, the second blade groups 131 and 132 can be driven.

  In addition, since the second blade group is disposed at a position facing the first blade group 121, 122, as shown in FIGS. 1B, 1C, and 1D, The aperture stop can be closed substantially symmetrically with the optical axis. By disposing the support pins 131b and 132b of the second blade group farther than the engagement pins 121a and 122a when viewed from the support pins 121b and 122b of the first blade group, an opening formed by the blades is formed. It becomes easy to change uniformly.

  Note that the engaging pins 121a and 122a of the blades 121 and 122 may be manufactured by using a metal shaft or the like as a separate part without being integrally formed and fixed to the blade by caulking or the like.

(Second embodiment)
FIG. 3 is a diagram showing the operation of the light quantity adjusting device in the second embodiment. In the present embodiment, in addition to the aperture blades whose aperture diameter is variable, the blades that function as ND filters are operated by the same drive source.

  3A is a top view of the light amount adjusting device when the aperture diameter of the aperture blade is maximized, FIG. 3B is a top view of the light amount adjusting device when the aperture is started, and FIG. 3C is FIG. FIG. 3D is a top view of the light amount adjusting device when further narrowing is performed than FIG. 3B, FIG. 3D is a top view of the light amount adjusting device when further narrowing is performed, and FIG. ) Is a top view of the light amount adjusting device when the aperture is fully closed.

  The light quantity adjusting device in the present embodiment is configured such that the ND filter enters the opening as the aperture diameter of the aperture blade is reduced.

  The electromagnetic drive source 140 and the drive lever 141 are the same as in the first embodiment. The first blade groups 221 and 222 are different in shape from the first embodiment, and are formed so that the aperture diameter can be adjusted by these two blades. Further, the engagement pin is provided only on the blade 221.

  The diaphragm blades are stacked on the base plate 210 in the order of the first blades 222 and 221, and the ND filter 233 is stacked on the first blade 221. The ND filter 233 is disposed so as to be rotatable with respect to the main plate 210 around the support pin 233b.

  As shown in FIG. 3A, the ND filter 233 is covered with an elastic member 251 having an urging force in a direction in which the blade retreats from the opening of the main plate. The ND filter 233 maximizes the aperture of the diaphragm blade. In this case, the outer edge 233a of the ND filter 233 is held at a position having a slight gap with the engagement pin 221a of the blade 221 by a stopper (not shown). By adjusting the size of the gap between the outer edge 233a of the ND filter and the engagement pin 221a of the blade 221 when the electromagnetic drive source is not energized, the ND filter 233 can be moved with respect to the start of movement of the first blade group 221 and 222. The movement start delay can be set freely.

  When the electromagnetic drive source 140 is energized and the drive lever 141 is rotated counterclockwise (driven toward the center of the main plate 210), the first blade groups 221 and 222 start moving in a narrowing direction and the engagement pin 221a is ND. The ND filter 233 comes into contact with the outer edge 233a of the filter 233, and the ND filter 233 also starts to move in the direction of entering the opening against the urging force of the elastic member 251.

  In the state of FIG. 3B, a part of the ND filter 233 has entered the aperture opening by the first blade group 221, 222. However, since the opening diameter is sufficiently large, the end face of the ND filter 233 There is almost no influence of diffraction and the like. In the state of FIG. 3C, a small aperture opening is formed by the first blade groups 221 and 222, and the ND filter 233 covers the entire opening, and there is no influence of diffraction or the like due to the end face of the ND filter.

  In the state of FIG. 3D, the aperture opening formed by the first blade groups 221 and 222 is further reduced, and the ND filter 233 covers the entire opening.

  In the state of FIG. 3 (e), the opening is completely covered by the first blade groups 221 and 222.

  Thus, by appropriately setting the shapes of the engagement pin 221a of the first blade 221 and the outer edge 233a of the ND filter 233, the ND filter can be arbitrarily inserted with respect to the aperture diameter.

  Of course, the ND filter 233 may not be manufactured entirely with the ND filter, but may be configured by manufacturing the minimum necessary shape with the ND filter and attaching it to the blades by bonding or the like.

(Third embodiment)
FIG. 4 is a diagram showing the operation of the light quantity adjusting device in the third embodiment.

  4A is a top view of the light amount adjusting device when the aperture diameter of the aperture blade is maximized, FIG. 4B is a top view of the light amount adjusting device when the aperture is started, and FIG. 4C is FIG. FIG. 4D is a top view of the light amount adjusting device when further narrowing is performed than FIG. 4B, FIG. 4D is a top view of the light amount adjusting device when further narrowing is performed, and FIG. ) Is a top view of the light amount adjusting device when the aperture is fully closed.

  As in the second embodiment, the light amount adjusting device in the present embodiment is configured such that the ND filter enters the opening as the aperture diameter of the aperture blade is reduced.

  The electromagnetic drive source 140 and the drive lever 141 are the same as in the first embodiment. The first blade groups 321 and 322 are different in shape from the first embodiment, and are formed so that the aperture diameter can be adjusted by these two blades. Further, the engaging pin is provided only on the blade 322.

  The diaphragm blades are stacked in the order of the first blade group 321 and 322 on the base plate 310, and the second blade 331 is further stacked on the blade 322 of the first blade group, and further on the ND filter. 333 is superimposed. Engagement pins 322a that are convex on the side opposite to the base plate side are integrally formed of plastic on the blades 322. As shown in FIG. 4A, the second blades 331 and the ND filter 333 are formed. Is fitted to both of the elongated hole-shaped driven portions 331a and 333a. The second blade 331 and the ND filter 333 are rotatably supported by the support pins 331a and 333a at positions facing the support pins 321a and 322a of the first blade group with the opening of the base plate 310 interposed therebetween. ing.

  When the blade 322 rotates, the engagement pin 322a moves in the driven portions 331a and 333a. The positions of the second blade 331 and the ND filter 333 are uniquely determined by the positions of the engagement pins 322a in the driven portions 331a and 333a. By appropriately forming the shapes of the driven portions 331a and 333a, the movement of the second blade 331 and the ND filter 333 can be freely set.

  When the electromagnetic drive source 140 is energized and the drive lever 141 rotates counterclockwise (drives toward the center of the main plate 310), the first blade groups 321 and 322 start moving in the narrowing direction and are fitted to the engagement pins 322a. The combined second blade 331 and ND filter 333 also start moving in a direction covering the opening.

  In the state of FIG. 4B, the aperture diameter is formed by three blades of the first blade group 321 and 322 and the second blade 331.

  In the state of FIG. 4C, a part of the ND filter 333 is invaded into the aperture diameter of the three blades of the first blade group 321, 322 and the second blade 331. Therefore, there is almost no influence of diffraction or the like by the end face portion of the ND filter 333.

  In the state of FIG. 4D, the aperture opening by the three blades by the first blades 321 and 322 and the second blade 331 is further reduced, and if the aperture diameter is further reduced, diffraction due to the aperture diameter is caused. Although there is a concern that it may occur, the effect of reducing the exposure amount can be obtained by the ND filter that covers the entire opening.

  In the state of FIG. 3E, the opening is completely covered by the first blade groups 321 and 322 and the second blade 331.

  As described above, the shape of the driven portions 331a and 333a of the second blade 331 and the ND filter 333 is appropriately set and fitted to the engagement pin 321a of the first blade 322, so that three pieces are obtained. In addition, the aperture diameter of the aperture blades can be formed, and an ND filter can be arbitrarily inserted into the aperture diameter, so that the aperture diameter can be made polygonal and the exposure control range can be widened.

  Further, since the driven portions 331a and 333a are fitted into the engaging pins 321a as long holes, the elastic member provided in the first and second embodiments can be omitted. Of course, the driven portions 331a and 333a are not formed into a long hole shape, and an elastic member for applying a biasing force to the blade 331 and the ND filter 333 is arranged as in the second embodiment, and the blade 331 and the ND filter 333 are connected by the engagement pin. It is good also as a structure extruded.

  Note that the ND filter 333 may be configured not to be manufactured by the ND filter in all shapes but to be manufactured by using the ND filter in the minimum necessary range and attached to the blades by bonding or the like.

(Fourth embodiment)
FIG. 5 is a diagram showing the operation of the light quantity adjusting device in the fourth embodiment.

  5A is a top view of the light amount adjusting device when the aperture diameter of the diaphragm blades is maximized, FIG. 5B is a top view of the light amount adjusting device when the aperture is started, and FIG. 5C is FIG. FIG. 5D is a top view of the light amount adjusting device when the aperture is further minimized as compared with FIG. 5B, and FIG. 5D is a top view of the light amount adjusting device when the aperture is minimized.

  The electromagnetic drive source 140 and the drive lever 141 are the same as in the first embodiment. As in the first embodiment, the first blade group including two blades 421 and 422 and the second blade group including two blades 431 and 432 are provided.

  The overlapping order of the blades is 422, 431, 421, and 432 from the main plate side, and two engagement pins 421a and 421c are integrally formed of plastic on the blade 421. The engagement pin 421a on the side close to the rotation center protrudes on the opposite side to the ground plane side, and the engagement pin 421c on the tip side of the blade projects on the ground plane side.

  As shown in FIG. 5A, elastic members 451 and 452 having a biasing force in the direction in which the blades open are hung on the second blade group 431 and 432, respectively, and an outer edge 431a of the blade 431 is placed. The outer edge 432a of the blade 432 is in contact with the engagement pins 421c and 421a of the blade 421, respectively. The support pins 421b and 422b of the first blade group and the support pins 431b and 432b of the second blade group are provided on the opposite sides across the opening of the base plate 410.

  When the electromagnetic drive source 140 is energized and the drive lever 141 is rotated counterclockwise (driven toward the center of the main plate 410), the first blade groups 421 and 422 start moving in a narrowing direction and the engagement pins 421c and 421a. The second blade groups 431 and 432 that are in contact with each other by the elastic members 451 and 452 also start moving in a direction to narrow down against the urging force of the elastic members 451 and 452.

  In this way, a polygonal diaphragm using four blades can be formed by integrally forming a plurality of engagement pins on the first blade 421 with plastic, and forming the other three blades as thin plates as before. It becomes.

  In FIG. 5, the rotation centers of the second blade groups 431 and 432 are on the same axis, but the present invention is not limited to this, and the rotation centers may be provided separately. However, as shown in FIG. 5, it is more advantageous in terms of dimensional management and space efficiency to share the rotation center of the second blade group 431,432.

  In each of the embodiments, the engagement pin is provided in the first blade group. However, the present invention is not limited to this configuration, and a configuration in which the engagement pin is provided in the second blade group may be used.

  Further, in each embodiment, the direction in which the urging force of the elastic member provided on the second blade group acts may be the closing direction instead of the blade opening direction. As shown in FIG. In the configuration in which the engagement pin and the driven portion of the second blade group are fitted, an elastic member for removing play between the engagement pin and the driven portion may be provided.

It is a figure which shows operation | movement of the aperture_diaphragm | restriction apparatus in a 1st Example. It is a perspective view of the diaphragm | throttle device in a 1st Example. It is a figure which shows operation | movement of the aperture_diaphragm | restriction apparatus in a 2nd Example. It is a figure which shows operation | movement of the aperture_diaphragm | restriction apparatus in a 3rd Example. It is a figure which shows operation | movement of the aperture_diaphragm | restriction apparatus in a 4th Example.

Explanation of symbols

110, 210, 310, 410 Ground plate 121, 122, 221, 222, 321, 322, 421, 422 First blade group 131, 132, 331, 431, 432 Second blade group 140 Drive source 141 Drive lever 233 333 ND filter 151,152,251,451,452 elastic member

Claims (11)

  A second member that includes a member having an opening, a first blade member that is driven by a drive source, and a fitting portion between the first blade member and moves following the movement of the first blade member. By having a blade member and driving the drive source in steps, the first blade member and the second blade member are superimposed on the opening, and the amount of light passing through the opening is adjusted in steps. Light quantity adjustment device to do.   The center of rotational movement of the second blade member is disposed at a position farther from the fitting portion than the center of rotational movement of the first blade member. Light quantity adjustment device.   3. The light amount adjusting device according to claim 1, comprising a plurality of combinations of the first blade member and a second blade member having a fitting portion between the first blade member and the first blade member. .   The light quantity adjusting device according to claim 3, wherein the plurality of first blade members are driven by a single drive source.   A member having an opening, a first blade member driven by a drive source, and a fitting portion of the first blade member, and a plurality of first blades that move following the movement of the first blade member A light amount adjusting device that has two blade members and adjusts the amount of light passing through the opening portion by superimposing the first blade member and the plurality of second blade members on the opening portion.   The light quantity adjusting device according to claim 5, wherein the plurality of second blade members are fitted in the same portion of the first blade member.   The light quantity adjusting device according to claim 5, wherein the plurality of second blade members are fitted to different portions of the first blade member.   A first blade member driven by a drive source; and a second blade member that includes a fitting portion between the first blade member and moves following the movement of the first blade member, One of the first blade member and the second blade member acts as a diaphragm blade member that forms an opening of varying size, and the other adjusts the amount of light that passes through the opening formed by the diaphragm blade member A light quantity adjusting device characterized by acting as a filter to perform.   9. The device according to claim 1, wherein when the first blade member moves within a predetermined range, the second blade member does not follow the movement of the first blade member. 10. Light quantity adjustment device.   An image pickup apparatus comprising the light amount adjustment device according to claim 1, further comprising an image pickup element that receives a light beam that has passed through the light amount adjustment device and forms an image signal.   An optical apparatus comprising the lens barrel that is mounted on an imaging apparatus that includes the light amount adjusting device according to claim 1 and that includes an imaging element that outputs an image signal by receiving light.

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