JP2005195675A - Light amount adjusting device, lens device and photographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize miniaturization and cost reduction, without decreasing the number of steps of switching the amount of light, when adjusting the amount of light by selectively inserting two diaphragm members in an exposure aperture part. <P>SOLUTION: An amount-of-light adjusting device is provided with a bottom board 101 which has a circular aperture part 101a (exposure aperture part) having an optical axis as center; a disk-like driving member 131, which is driven to be rotated by a single stepping motor 151 and has columnar pressing parts 133 and 134 at different angular positions on both front and back surfaces; and 1st and 2nd oval diaphragm members 111a and 121a turned individually, by the respective pressing parts 133 and 134 on both front and back surfaces of the member 131 so as to advance to/retreat from the exposure aperture part, by interlocking with the rotation of the driving member 131. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an imaging device such as a video camera, or a lens device, and a light amount adjusting device built in the device.

  For ordinary cameras that use photographic film, video cameras with built-in solid-state image sensors, and digital cameras, adjust the focal depth of the lens and the amount of light in the field that is imaged on the film or solid-state image sensor. In order to adjust the aperture, an aperture mechanism for controlling the aperture diameter at the exposure opening is provided. Currently, as a diaphragm mechanism generally used, a plurality of blades are used and the aperture is continuously changed around the optical axis like an iris, and a plurality of aperture members having a smaller aperture than the exposure aperture Is known to be selectively inserted into the exposure opening.

  The former diaphragm mechanism has the advantage that the diaphragm aperture can be continuously changed, but it is difficult to obtain a diaphragm aperture with a good roundness evenly over large and small apertures. There is a drawback that it is very difficult to manufacture a small-diameter aperture. On the other hand, the latter diaphragm mechanism has the advantage that a very good roundness diaphragm opening can be obtained, but there is a drawback that it is practically impossible to obtain a diaphragm opening having a multistage aperture.

  On the other hand, with the narrowing of the interval between unit light-receiving portions of the solid-state imaging device, so-called pixel pitch, the influence of diffraction due to the aperture opening for adjusting the amount of light of the photographing optical system cannot be ignored. In other words, when the aperture is reduced during high-luminance subject shooting or slow shutter shooting, the contrast of the image decreases due to the effect of so-called small aperture diffraction, and the imaging performance inherent in the imaging optical system and the high pixel capability of the solid-state imaging device Is not sufficiently exhibited, resulting in a problem that a high-definition image cannot be obtained.

  Therefore, in order to alleviate small aperture diffraction, a neutral density filter (hereinafter referred to as an ND filter) for attenuating transmitted light amount is often used as an aperture member that is selectively inserted into the exposure aperture.

  For example, in Japanese Patent Application Laid-Open No. 2001-174862, an aperture plate having an aperture smaller than the exposure aperture and an aperture member made up of a light amount adjustment filter (ND filter) are driven by separate actuators, respectively, The exposure aperture is covered with the aperture member, and the exposure aperture is covered with both the aperture plate and the aperture member, and is not covered. Yes.

Japanese Patent Application Laid-Open No. 11-149104 discloses a mechanism that drives two ND filters having different densities with one actuator and puts them in and out of the exposure opening.
JP 2001-174862 A JP 11-149104 A

  However, in Japanese Patent Laid-Open No. 2001-174862, since the diaphragm plate and the diaphragm member are driven by separate actuators, it is difficult to reduce the size and price. There was a problem that two ND filters could not be overlapped and only three-level light quantity switching was possible.

  Accordingly, the present invention provides a light amount adjusting device and a lens that can be reduced in size and price without reducing the number of steps of light amount switching when the two aperture members are selectively inserted into the exposure opening to perform light amount adjustment. It is an object to provide an apparatus and a photographing apparatus.

  In order to achieve the above object, a light amount adjusting device according to the present invention is a ground plate having a circular exposure opening centered on an optical axis, and a plate-like drive member that is rotationally driven by one actuator, A driving member having a pressing portion on each of the front and back surfaces, and a first rotating forward and backward to the exposure opening by being individually rotated by each pressing portion on both the front and back surfaces of the driving member in conjunction with the rotation of the driving member. And a second diaphragm member.

  According to the present invention, a light amount adjusting device and a lens that can be reduced in size and price without reducing the number of steps of light amount switching when the two aperture members are selectively inserted into the exposure opening to perform light amount adjustment. It is possible to provide a device and a photographing device.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is an exploded perspective view of a main part of a light amount adjusting apparatus 100 according to the first embodiment of the present invention.

  In FIG. 1, a circular base plate 101 is formed with a circular opening 101 a and a hole 101 b for passing a light beam. The rotation shaft 151a of the step motor 151 is passed through the hole 101b of the main plate 101. Further, the base plate 101 is formed with a cylindrical portion 101c for accommodating first and second light amount adjusting members 111 and 121 and a driving member 131 which will be described later.

  The first light amount adjusting member 111 is made of a transparent resin film having a thickness of about 0.1 mm, for example, a PET (polyethylene terephthalate) film, and is an oval neutral density filter unit (hereinafter referred to as an ND unit) for attenuating transmitted light amount. ) 111a is formed. Portions other than the ND portion 111a (first diaphragm member) of the first light quantity adjusting member 111 are light shielding portions that block light.

  A bearing 112 is formed on the first light quantity adjusting member 111, and a rotating shaft 151a of a stepping motor 151 described later is inserted into the bearing 112 so that the first light quantity adjusting member 111 is rotatably supported. The

  The second light quantity adjusting member 121 is made of a transparent resin film having a thickness of about 0.1 mm, for example, a PET (polyethylene terephthalate) film, and is an oval apodization filter part (hereinafter referred to as an AP part) for attenuating transmitted light quantity. 121a is formed. Portions other than the AP portion 121a (second aperture member) of the second light quantity adjusting member 121 are light shielding portions that block light.

  A bearing 122 is formed on the second light quantity adjusting member 121, and a rotation shaft 151a of a stepping motor 151 described later is inserted into the bearing 122 so that the second light quantity adjusting member 121 is rotatably supported. The

  The disk-shaped drive member 131 drives the first and second light quantity adjusting members 111 and 121, and a hole 132 is formed at the center thereof, and the rotation shaft 151 a of the stepping motor 151 is formed in the hole 132. By being press-fitted, the driving member 131 rotates integrally with the rotating shaft 151a of the stepping motor 151. Further, the driving member 131 is provided with a cylindrical first pushing portion 133 and a second pushing portion 134, and the first and second pushing portions 133, 134 are accompanied with the rotation of the driving member 131. Pushes the first and second light quantity adjusting members 111 and 121, respectively. The drive member 131 will be described in detail later with reference to FIG.

  The circular cover plate 141 forms a predetermined space between the ground plate 101 and the first and second light quantity adjusting members 111 and 121 and the drive member 131 are accommodated in the space. In the center of the cover plate 141, a circular opening 141a for passing a light beam having the same diameter as the opening 101a of the base plate 101 is formed.

  In the assembled state, the opening 101a of the base plate 101 and the opening 141a of the cover plate 141 are in a positional relationship such that the ridges overlap like one opening (not closely attached, there is a gap) The center thereof is disposed on the optical axis and functions as an exposure opening for the solid-state imaging device 440 (see FIG. 5). When the ND portion 111a and the AP portion 121a rotate, the center line in the longitudinal direction passes through the center of the exposure opening.

  2A and 2B are plan views for explaining the details of the ND portion 111a of the first light amount adjusting member and the AP portion 121a of the second light amount adjusting member, respectively. As shown in FIGS. 2A and 2B, the ND portion 111a and the AP portion 121a have the same shape (oval shape) and the same size, and their vertical width (width in the short direction) is exposure. It is slightly larger than the diameter of the opening, and the lateral width (width in the longitudinal direction) is slightly larger than twice the diameter of the exposure opening, so that the exposure opening can be completely covered.

  The optical density (light transmittance) of the ND part 111a shown in FIG. 2A is 0.45 (the number of ND stages is 1.5), and the entire surface has a uniform optical density. That is, the ND part 111a has a characteristic of reducing the light transmittance uniformly over the entire surface.

  In the AP section 121a shown in FIG. 2B, the optical density continuously changes in the radial direction from two centers (density centers) on the center line in the longitudinal direction. In other words, each optical density pattern of the AP portion 121a is configured such that the optical density continuously changes in the radial direction from the center of the exposure opening when each of the optical density patterns covers the exposure opening. ing. In this embodiment, the optical density increases in the radial direction from each density center. Specifically, the optical density at the density center is 0, the optical density gradually increases in the radial direction, and the maximum optical density value is 1.2. That is, the AP part 121a has a characteristic that the light transmittance is gradually reduced as the distance from the density center increases.

  Due to this characteristic, the AP unit 121a has an effect that the density of the peripheral edge of the blur is gradually reduced and the blur is softened as a whole for a still image. In addition, for a moving image, an image that is thin at the start of exposure and becomes darker as the end of exposure is obtained can be obtained, and the effect of expressing the direction and degree of movement can be obtained. Such an effect of the AP part 121a is referred to as an apodization effect. Note that the above-described density patterns of the ND part 111a and the AP part 121a and the light-shielding parts of the first and second light quantity adjusting members 111 and 121 are formed by an inkjet printing method (for example, see Japanese Patent Application Laid-Open No. 2000-117960). Can be realized.

  3A and 3B are a front view and a side view of the drive member 131, respectively. As shown in FIG. 3A, the first pushing portion 133 and the second pushing portion 134 of the driving member 131 have a phase of a line connecting to the hole 132 only by θ1 (25 ° in this embodiment). They are arranged so as to be displaced. Further, as shown in FIG. 3B, the first pushing portion 133 and the second pushing portion 134 protrude from the front surface or the back surface of the disk-shaped drive member 131. In other words, the first pushing portion 133 and the second pushing portion 134 are different from the first light amount adjusting member 111 including the ND portion 111a and the second light amount adjusting member 121 including the AP portion 121a. Each of them is driven on a plane.

  In this way, the first pushing portion 133 and the second pushing portion 134 are arranged with the phases shifted from each other, and are arranged on different surfaces of the driving member 131, so that a later-described pulling spring 113 is provided. , 123, the exposure aperture can be simultaneously covered with the ND part 111a and the AP part 121a, individually covered, and not simultaneously covered.

  Next, drive control of the first and second light quantity adjusting members 111 and 121 will be described with reference to FIG.

FIG. 4A shows a state in which the first and second light quantity adjusting members 111 and 121 are located at the initial positions. In this state, the stepping motor 151 is not energized. The first and second light quantity adjusting members 111 and 121 are overlapped at the initial position (in reality, they are not in close contact with each other and there is a gap corresponding to the thickness of the drive member 131). By the force (contraction force), it is retracted to the position adjacent to the opening 101a (exposure opening). One end of the tension spring 113 is locked to the cylindrical portion 101 c of the base plate 101, and the other end is locked to the first light quantity adjusting member 111. One end of the tension spring 123 is locked to the cylindrical portion 101 c of the base plate 101, and the other end is locked to the second light quantity adjusting member 121.

  In this initial state, the first pushing portion 133 of the driving member 131 is in contact with the first light amount adjusting member 111, but the second pushing portion 134 is the first pushing portion as described above. Since it is out of phase with 133, it is not in contact with the second light quantity adjustment member 121.

  In the case where it is desired to take an image with an increased exposure amount for the solid-state imaging device 440, the image is taken in the state of FIG. 4A without energizing the stepping motor 151.

  FIG. 4B is a view when the stepping motor 151 is rotated 25 ° counterclockwise. In this case, in conjunction with the rotation of the stepping motor 151, the driving member 131 and the first and second pushing portions 133 and 134 on the driving member 131 also rotate 25 ° counterclockwise.

  By the rotation of the driving member 131, the first light quantity adjusting member 111 is pushed by the first pushing portion 133 and rotated by 25 °, and the left half portion of the ND portion 111a is the opening portion 101a (exposure opening portion). Cover. However, the second pushing portion 134 only comes into contact without pushing the second light amount adjusting member 121. Therefore, when the driving member 131 rotates 25 ° counterclockwise, only the ND portion 111a covers the opening portion 101a (exposure opening portion). If it is desired to shoot with a slightly reduced exposure to the solid-state image sensor 440, the shoot should be performed in the state shown in FIG.

  FIG. 4C is a diagram when the driving member 131 is rotated counterclockwise by 50 ° from the initial state. As the driving member 131 rotates, the first light amount adjusting member 111 is pushed by the first pushing portion 133 and rotates by 50 ° from the initial state, and the right half portion of the ND portion 111a is the opening portion 101a. Cover. Further, the second light amount adjusting member 121 is pushed by the second pushing portion 134 and rotated 25 ° from the initial state, and the left half of the AP portion 121a covers the opening portion 101a (exposure opening portion). That is, both the ND part 111a and the AP part 121a are in a state of covering the opening part 101a (exposure opening part). When taking an image with a slightly reduced exposure to the solid-state imaging device 440 while obtaining an apodization effect, the image may be taken in the state of FIG.

  FIG. 4D is a diagram when the driving member 131 is rotated counterclockwise by 75 ° from the initial state. With the rotation of the drive member 131, the first light amount adjusting member 111 is pushed by the first pushing portion 133 and rotated by 75 ° from the initial state, and the first light amount adjusting member 111 has the opening 101a ( Retract from the exposure opening). Further, the second light amount adjusting member 121 is pushed by the second pushing portion 134 and rotated by 50 ° from the initial state, and the right half of the AP portion 121a covers the opening 101a. That is, only the AP portion 121a covers the opening 101a (exposure opening). When taking an image with an increased exposure to the solid-state imaging device 440 while obtaining an apodization effect, the image may be taken in the state of FIG.

  As described above, the first light intensity adjusting member 111 having the oval ND portion 111a and the second light intensity adjusting member 121 having the oval AP portion 121a are shifted in phase from each other. A driving member 131 having a moving part 133 and a second pushing part 134 is provided, and the driving member 131 is rotated by one stepping motor 151, whereby the first light quantity adjusting member 111 is made by the first pushing part 133. Since the second light quantity adjusting member 121 can be pushed by the second pusher 134, the ND part 111a and the AP part 121a cover the exposure opening (including a state where it is not covered). Can be changed in four stages. In other words, it is possible to reduce the size and the price without reducing the number of steps of light quantity switching.

  FIG. 5 is a block diagram illustrating a schematic configuration of the imaging apparatus. The imaging apparatus is an electronic camera such as a video camera that incorporates a solid-state imaging device and shoots still images / moving pictures, and a digital camera that shoots still pictures. The light quantity adjusting device 100 is configured and described with reference to FIGS. In addition, it is also possible to mount the light quantity adjustment apparatus 600 shown in FIGS.

  In addition to the light amount adjusting device 100, the photographing optical system 400 includes a fixed front lens group 401, a variator lens group 402 that performs a zooming operation by moving along the optical axis, and a movement along the optical axis. It has a focusing lens group 403 that performs focal plane maintenance and focusing at the time of zooming, an optical low-pass filter 404, and a shutter mechanism 405 that adjusts the exposure time.

  In addition, a solid-state image sensor (CCD) 440 is disposed at the focal position (scheduled imaging plane) of the photographing optical system 400. The CCD 440 includes a plurality of photoelectric conversion units (pixels) that convert irradiated light energy into charges, a charge storage unit that stores the charges, and a charge transfer unit that transfers the charges and sends them to the outside. The drive control of the CCD 440 is performed by the CCD drive circuit 434 under the control of the CPU 431.

  The subject image formed on the CCD 440 is converted into an electric signal as a charge amount for each pixel corresponding to the intensity of the brightness, amplified by the amplifier circuit 441, and then subjected to A / D conversion processing by the image signal processing circuit 442. Predetermined image processing such as γ correction processing and white balance processing is performed. The video signal subjected to the image processing is recorded in the memory 443. As the memory 443, various types of devices such as a semiconductor memory such as a flash ROM, an optical memory such as a magneto-optical disk, and a magnetic memory such as a magnetic tape can be used.

  The display 421 is configured by a liquid crystal display or the like, and displays an image captured by the CCD 440 and an operation status of the imaging apparatus. The operation switch group 422 includes a zoom switch, a shooting preparation switch, a shooting start switch, a shooting mode selection switch for selecting a still image mode and a moving image mode, a shooting condition switch for setting an exposure control mode, an AF mode, and the like, an ND filter (ND section) 111 a) and an apodization switch for selecting whether or not to use an apodization filter (AP unit 121a).

  The zoom actuator 423 drives the variator lens group 402 under the control of the CPU 431 and changes the focal length of the photographing optical system 400. The focus actuator 424 drives the focusing lens group 403 under the control of the CPU 431 and adjusts the focusing state of the photographing optical system 400. The light amount adjusting member drive circuit 432 adjusts the exposure amount for the CCD 440 by driving the stepping motor 151 under the control of the CPU 431. The shutter drive circuit 433 drives the shutter mechanism 405 under the control of the CPU 431 and controls the exposure time for the CCD 440.

[Second Embodiment]
Since the first and second pushing portions 133 and 134 of the driving member 131 in the first embodiment are cylindrical, two places are required as retraction spaces for the first and second light quantity adjusting members 111 and 121. there were. In the second embodiment, the shape of the pushing portion of the driving member is an arc shape, so that the retreat space for the first and second light quantity adjusting members is one place, and further miniaturization is possible. Yes.

  FIG. 6 is an exploded perspective view of a main part of a light amount adjustment device 600 according to the second embodiment of the present invention.

  In FIG. 6, a circular base plate 601 is formed with a circular opening 601a, a hole 601b, and a rotation support shaft 602 for passing a light beam. The rotation shaft 651a of the step motor 651 passes through the hole 601b. The rotation support shaft 602 of the base plate 601 is penetrated by bearings 612 and 622 formed on the first and second light quantity adjustment members 611 and 621 so that the first and second light quantity adjustment members 611 and 621 can rotate. Support.

  The first light quantity adjusting member 611 is made of a transparent resin film having a thickness of about 0.1 mm, for example, a PET (polyethylene terephthalate) film, and has a circular neutral density filter part (hereinafter referred to as an ND part) for attenuating transmitted light quantity. 611a is formed. Portions other than the ND portion 611a (first diaphragm member) of the first light amount adjusting member 611 are light shielding portions that block light. The optical density (light transmittance) of the ND unit 611a is 0.45 (the number of ND stages is 1.5), and the optical density is uniform over the entire surface. That is, the ND portion 611a has a characteristic of reducing the light transmittance uniformly over the entire surface.

  The second light quantity adjusting member 621 is made of a transparent resin film having a thickness of about 0.1 mm, for example, a PET (polyethylene terephthalate) film, and has a circular apodization filter part (hereinafter referred to as AP part) 621a for attenuating transmitted light quantity. Is formed. Portions other than the AP portion 621a (second aperture member) of the second light quantity adjusting member 621 are light shielding portions that block light.

  In the AP unit 621a, the optical density continuously changes in the radial direction from the center, and in the present embodiment, the optical density increases in the radial direction from the center. Specifically, the optical density at the center is 0, the optical density gradually increases in the radial direction, and the maximum value of the optical density is 1.2. That is, the AP unit 621a has a characteristic of gradually reducing the light transmittance as the distance from the concentration center increases. With this characteristic, the AP section 621a can obtain the apodization effect described above.

  The circular ND portion 611a and the AP portion 621a have the same diameter, and the diameter is slightly larger than the diameter of the exposure opening, so that the exposure opening can be completely covered. Further, the density patterns of the ND unit 611a and the AP unit 621a and the light shielding units of the first and second light quantity adjusting members 611 and 621 can be realized by the above-described ink jet printing method.

  The disk-shaped drive member 631 drives the first and second light quantity adjusting members 611 and 621, and a hole 632 is formed at the center thereof. A rotation shaft 651 a of the stepping motor 651 is formed in the hole 632. By being press-fitted, the driving member 631 rotates integrally with the rotating shaft 651a of the stepping motor 651. The drive member 631 is provided with an arc-shaped first pusher 633 and a second pusher 634, and the first and second pushers 633 and 634 are rotated with the rotation of the drive member 631. Pushes the first and second light quantity adjusting members 611 and 621, respectively. The drive member 631 will be described in detail later with reference to FIG.

  The circular cover plate 641 forms a predetermined space between the ground plate 601 and the first and second light quantity adjusting members 611 and 621 and the driving member 631 are accommodated in the space. In the center of the cover plate 641, a circular opening 641 a for passing a light beam having the same diameter as the opening 601 a of the base plate 601 is formed.

  In the assembled state, the opening 601a of the base plate 601 and the opening 641a of the cover plate 641 are in a positional relationship such that the heel overlaps like one opening (not closely contacted, there is a gap) The center thereof is disposed on the optical axis and functions as an exposure opening for the solid-state imaging device 440 (see FIG. 5). Further, when the ND portion 611a and the AP portion 621a rotate, the centers thereof pass through the center of the exposure opening.

  7A and 7B are a front view and a side view of the drive member 631, respectively. As shown in FIG. 7A, the first pushing portion 633 and the second pushing portion 634 of the driving member 631 are only in the phase of the line connecting with the hole 632 by θ2 (90 ° in this embodiment). They are arranged so as to be displaced. Further, as shown in FIG. 7B, the first pushing portion 633 and the second pushing portion 634 are provided on the front surface or the back surface of the disk-shaped drive member 631. In other words, the first pushing portion 633 and the second pushing portion 634 are different from the first light amount adjusting member 611 including the ND portion 611a and the second light amount adjusting member 621 including the AP portion 621a. Each of them is driven on a plane.

  In this way, the first pushing portion 633 and the second pushing portion 634 are arranged with the above-mentioned phases shifted, and are arranged on different surfaces of the driving member 631, so that a later-described pulling spring 613 is arranged. , 623, it is possible to realize four aperture states in which the exposure opening is simultaneously covered with the ND portion 611a and the AP portion 621a, individually covered, and not simultaneously covered.

  Next, drive control of the first and second light quantity adjusting members 611 and 621 will be described with reference to FIG.

  FIG. 8A shows a state in which the first and second light quantity adjusting members 611 and 621 are located at the initial position. In this state, the stepping motor 651 is not energized. The first and second light quantity adjustment members 611 and 621 are in an overlapping position at the initial position (not closely contacted and have a gap corresponding to the thickness of the drive member 631), and the urging forces of the tension springs 613 and 623, respectively. By (shrinkage force), it is retracted to a position adjacent to the opening 601a (exposure opening). One end of the tension spring 613 is locked to the cover plate 641, and the other end is locked to the first light quantity adjustment member 611. One end of the tension spring 623 is locked to the ground plate 601, and the other end is locked to the second light quantity adjusting member 621.

  In this initial state, the left end of the first pushing portion 633 of the driving member 631 is in contact with the first light amount adjusting member 611, but the second pushing portion 634 is the first pushing portion as described above. Since it is out of phase with the pusher 633, it is not in contact with the second light quantity adjustment member 621.

  In the case where it is desired to take an image with an increased exposure amount for the solid-state image sensor 440, the image is taken in the state of FIG. 8A without energizing the stepping motor 651.

  FIG. 8B is a diagram when the stepping motor 651 rotates 90 ° counterclockwise. In this case, in conjunction with the rotation of the stepping motor 651, the driving member 631 and the first and second pushing portions 633 and 634 on the driving member 631 also rotate 90 ° counterclockwise.

  By the rotation of the driving member 631, the first light amount adjusting member 611 is pushed by the first pushing portion 633 and rotated by 45 °, and the ND portion 611a covers the opening portion 601a (exposure opening portion). However, the second pushing portion 634 only comes into contact with the left end without pushing the second light amount adjusting member 621. Therefore, when the driving member 631 is rotated 90 ° counterclockwise, only the ND portion 611a covers the opening 601a (exposure opening). If it is desired to shoot with a slight reduction in the amount of exposure to the solid-state imaging device 440, it is sufficient to shoot in the state of FIG.

  FIG. 8C is a diagram when the driving member 631 is rotated 180 ° counterclockwise from the initial state. As the drive member 631 rotates, the first light amount adjusting member 611 is pushed by the first pushing portion 633. However, the first pushing portion 633 is arcuate and is not turned. The part 611a keeps the state of covering the opening 601a (exposure opening).

  On the other hand, the second light amount adjusting member 621 is pushed by the second pushing portion 634 of the driving member 631 and rotated by 45 °, and the AP portion 621a also covers the opening portion 601a (exposure opening portion). That is, both the ND portion 611a and the AP portion 621a cover the opening 601a (exposure opening). When taking an image with a slightly reduced exposure amount for the solid-state imaging device 440 while obtaining an apodization effect, the image may be taken in the state of FIG.

  FIG. 8D is a diagram when the driving member 631 is rotated 270 ° counterclockwise from the initial state. As the drive member 631 rotates, the first pusher 633 does not come into contact with the first light amount adjusting member 611. Therefore, the first light amount adjusting member 611 returns to the initial position by the contraction force of the pulling spring 613. Retreat from the opening 101a (exposure opening).

  On the other hand, the second light quantity adjusting member 621 is pushed by the second pushing portion 634. Since the second pushing portion 634 has an arc shape, the AP portion 121a has an opening portion 601a (exposure opening portion). Keep covered. That is, only the AP portion 621a covers the opening 601a (exposure opening).

  When taking an image with an increased exposure amount for the solid-state imaging device 440 while obtaining an apodization effect, the image may be taken in the state of FIG.

  The present invention is not limited to the first and second embodiments described above. For example, each light amount adjusting member is manufactured by an ink jet printing method, but may be manufactured by a vapor deposition method, another printing method, or the like. Absent. In the first and second embodiments, the first and second light quantity adjusting members are manufactured integrally with the ND portion (or AP portion) and the other portion (light shielding portion). After the body is manufactured, the ND portion (or AP portion) may be attached to the hole formed in the light shielding portion with an adhesive or the like. Furthermore, the material of the first and second light quantity adjusting members in the first and second embodiments may be glass instead of the transparent resin film.

  Further, as a modification of the first embodiment, one light amount adjusting member is formed with three ND portions having different optical densities and uniform optical density on the entire surface, and the other light amount adjusting member has an optical density It is also possible to realize a six-stage aperture state by forming three AP portions having different change patterns. However, in this case, there is a possibility that it is somewhat difficult to reduce the size, but this drawback does not become a problem when the exposure opening is made small.

  As a modification of the first and second embodiments, it is also possible to form a diaphragm hole in one light amount adjusting member and form an ND portion or an AP portion in the other light amount adjusting member. Further, the AP unit in the first and second embodiments may be configured such that the light transmittance does not change continuously but changes stepwise.

  Furthermore, the phase angle between the columnar first pushing portion and the second pushing portion on the drive member in the first embodiment may be a phase angle other than 25 °, and the second embodiment. The phase angle between the arc-shaped first pushing portion and the second pushing portion on the driving member may be a phase angle other than 90 °.

  The first and second tension springs in the first and second embodiments can be replaced with other types of springs such as a push spring, a torsion spring, a leaf spring, and a spring.

It is a principal part disassembled perspective view of the light quantity adjustment apparatus which concerns on the 1st form of this invention. It is a figure which shows the optical density of ND part and AP part which concern on the 1st form of this invention. It is the top view and side view of the drive member which concern on the 1st form of this invention. It is a figure for demonstrating drive control of the light quantity adjustment member which concerns on the 1st form of this invention. It is a block diagram which shows schematic structure of the imaging device carrying the light quantity adjustment apparatus which concerns on the 1st, 2nd embodiment of this invention. It is a principal part disassembled perspective view of the light quantity adjustment apparatus which concerns on the 2nd form of this invention. It is the top view and side view of the drive member which concern on the 2nd form of this invention. It is a figure for demonstrating drive control of the light quantity adjustment member which concerns on the 2nd form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,600 ... Light quantity adjustment apparatus, 101,601 ... Ground plane, 101a, 141a, 601a, 641a ... Opening part (exposure opening part), 101b, 132, 601b, 632 ... Hole, 602: Rotation support shaft, 111,611 ... 1st light quantity adjustment member, 111a, 611a ... ND part, 112, 122, 612, 622 ... bearing, 113, 123, 613, 623 ... tension spring, 121, 621 ... 2nd light quantity adjustment member, 121a, 621a ... AP section, 131, 631 ... driving member, 133, 633 ... first pushing section, 134, 634 ... second pushing section, 141, 641 ... cover plate, 151, 651 ... stepping motor, 151a, 651a ... Axis of rotation

Claims (13)

A ground plane having a circular exposure opening centered on the optical axis;
A plate-like drive member that is rotationally driven by one actuator, each having a pushing portion on both the front and back surfaces;
In conjunction with the rotation of the drive member, a first diaphragm member, a second diaphragm member that is individually rotated by the respective pushing portions on both the front and back surfaces of the drive member and advances and retracts to the exposure opening,
A light amount adjusting device comprising:   The first and second diaphragm members both enter the exposure opening according to the rotation angle of the drive member, or either one enters the exposure opening, or both The light amount adjusting device according to claim 1, wherein the light amount adjusting device is in a state of not entering the exposure opening.   3. The light amount adjusting device according to claim 1, wherein the pressing portions on both the front and back surfaces of the driving member are arranged so as to have a constant phase angle with each other.   The light quantity adjusting device according to any one of claims 1 to 3, wherein the pressing portions on both the front and back surfaces of the driving member are both cylindrical.   The first diaphragm member and the second diaphragm member are both oval in shape, the widths in the longitudinal direction are both slightly larger than multiple times the diameter of the exposure opening, and the widths in the short direction are both The light amount adjusting device according to claim 4, wherein the light amount adjusting device is slightly larger than a diameter of the exposure opening.   The light quantity adjusting device according to any one of claims 1 to 3, wherein the pressing portions on both the front and back surfaces of the driving member are arcuate.   7. The light amount adjusting device according to claim 6, wherein the first diaphragm member and the second diaphragm member are both circular in shape, and both have a diameter slightly larger than the diameter of the exposure opening.   8. The light quantity adjusting device according to claim 1, wherein both the first diaphragm member and the second diaphragm member are urged in a direction of retreating from the exposure opening by a spring. .   The first diaphragm member and the second diaphragm member are diaphragm members that reduce the light transmittance at the exposure opening, and the first diaphragm member has a uniform light transmittance over the entire surface. The second diaphragm member has a pattern in which light transmittance changes continuously or stepwise in a radial direction from the center of the exposure opening in a state where the exposure opening is covered. The light quantity adjustment apparatus in any one of 1-8. A ground plane having a circular exposure opening centered on the optical axis;
A disk-shaped drive member that is rotationally driven by one actuator, and a drive member that has a cylindrical pusher at different angular positions on the front and back surfaces;
In conjunction with the rotation of the drive member, an oval first diaphragm member and a second diaphragm member that are individually rotated by the pushing portions on both the front and back surfaces of the drive member to advance and retract to the exposure opening. Both of the widths in the longitudinal direction are slightly larger than a plurality of times the diameter of the exposure opening, and the widths in the short direction are both slightly larger than the diameter of the exposure opening, both from the exposure opening by a spring. A first throttling member and a second throttling member biased in the retreating direction;
A light amount adjusting device comprising: A ground plane having a circular exposure opening centered on the optical axis;
A disk-shaped driving member that is rotationally driven by one actuator, and a driving member having arcuate pushing portions at different angular positions on the front and back surfaces;
In conjunction with the rotation of the driving member, a circular first diaphragm member and a second diaphragm member that are individually rotated by the respective pushing portions on both the front and back surfaces of the driving member to advance and retract to the exposure opening. A first diaphragm member and a second diaphragm member, both of which are slightly larger in diameter than the exposure opening, and both are biased in a direction of retreating from the exposure opening by a spring;
A light amount adjusting device comprising:   A lens device comprising the light amount adjusting device according to claim 1.   An imaging apparatus comprising the light amount adjusting device according to claim 1.

Images