JP6314033B2 - Light amount adjusting device and optical apparatus - Google Patents

Description

  The present invention relates to an apparatus for adjusting the amount of light such as a diaphragm device or a shutter device incorporated in a lens of a digital still camera, a digital video camera, or a portable device.

  In a light amount adjustment device mounted on a lens of a digital still camera, digital video camera, portable device, etc., the aperture for transmitting light from the subject is formed by a plurality of light shielding members, and the aperture area and aperture are opened. Thus, the amount of light reaching the image sensor is controlled, and the optimum amount of light intended by the photographer is given to the image sensor. In other words, it is common to use a device in which a plurality of light shielding members collaborate to form an aperture that allows light to pass through, and the aperture size is adjusted to the intended area, or the aperture can be opened for the intended time. Is.

In Patent Document 1, a ground plate having a caliber portion, a motor attached to the ground plate, a step disposed parallel to the surface of the ground plate and provided in parallel with the surface of the ground plate by the motor and moved in opposite directions. An example of a light amount adjusting device that can change the area of the aperture portion by two diaphragm blades is disclosed.
Further, Patent Document 2 discloses a method of increasing the number of blades having the same shape and installing them as a method for improving the difference in the amount of light on the image pickup element surface due to the steps of the diaphragm blades.

Japanese Patent Laid-Open No. 04-145422 JP 05-66460 A

  However, in the configuration of Patent Document 1 described above, since the light shielding member is not on the same plane as pointed out in Patent Document 2, the amount of light reaching the image sensor is different depending on the position of the light shielding member that shields light from the subject. There was a problem that came out.

  In Patent Document 2, two light-shielding members having the same shape are arranged on the subject side and the image sensor side to improve the difference in the amount of light reaching the image sensor. However, as a result, the number of light shielding members increases, and the thickness of the portion forming the aperture is increased by one light shielding member.

  The present invention relates to a technique for reducing a difference in the amount of light reaching the position of an image sensor with a small and minimum number of parts.

The present invention is, for example,
By moving the optical axis and the straight direction orthogonal, and two light shielding member that adjusts the amount of light reaching the image sensor,
A drive unit for driving the two light shielding members,
By driving the plurality of light shielding members by the driving unit, the size of the aperture formed by the two light shielding members is adjusted,
The portions forming the apertures of the plurality of light shielding members are chamfered on the surface opposite to the surface where the two light shielding members face each other in the direction of the optical axis .
There is provided a light amount adjusting device characterized by the above.
The present invention also provides, for example,
A plurality of light shielding members that adjust the amount of light reaching the image sensor by moving in a direction orthogonal to the optical axis;
A drive unit that drives the plurality of light shielding members,
The drive unit drives the plurality of light shielding members to adjust the size of the aperture formed by the plurality of light shielding members, and among the plurality of light shielding members, the diameter of the light shielding member closest to the image sensor Chamfering is applied to both the image sensor side of the portion that forms the aperture and the subject side of the portion that forms the aperture of the light shielding member closest to the subject
There is provided a light amount adjusting device characterized by the above.

  ADVANTAGE OF THE INVENTION According to this invention, the small light quantity adjustment apparatus which reduced the difference of the light quantity which reaches | attains an image pick-up element can be provided.

1 is a cross-sectional view of an apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view of the drive device shown in FIG. It is a perspective view of the apparatus concerning the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
Reference numeral 1 denotes a motor for driving the light shielding member, which is fixed to the main plate 2. A drive lever 3 is fixed to the output shaft of the motor 1 and rotates in conjunction with the rotation of the motor 1. The drive lever 3 has cylindrical convex portions 3a and 3b, and is slidably fitted to the blade 4 and the long hole portions 4a and 5a of the blade 5 which are light-shielding members, respectively, and according to the rotated position of the drive lever 3. The blade 4 and the blade 5 also move in conjunction with each other.

  At this time, the blade 4 is held so that the long holes 4b and 4c are slidable on the convex portions 2c and 2d of the base plate 2, and similarly the blade 5 is held so that the long holes 5b and 5c are slidable on the convex portions 2a and 2b of the base plate 2. Therefore, the blades 4 and 5 are configured to move in opposite directions.

  The holding plate 6 is fixed to the base plate 2 at a position that secures an operating space for the blades 4 and 5 in order to prevent the blades 4 and 5 from being detached from the convex portions 2 c and 2 d of the base plate 2.

  The blades 4 and 5 have notches 4d and 5d formed by arcs for forming the aperture diameter or a combination of arcs and straight lines. The light reaching the image sensor from the subject is adjusted by the area of the aperture surrounded by the notches 4d and 5d of the blade 4 and the blade 5.

As shown in the cross section of FIG. 1, the notch 4d of the blade 4 is chamfered, the blade 5 on the side close to the subject gives a surface or the like to the surface on the subject side, and the blade 4 on the side close to the image sensor. Chamfers the surface on the image sensor side. Thereby, the small light quantity adjustment apparatus which reduced the difference of the light quantity which reaches | attains an image pick-up element can be provided.
In addition, the sliding surfaces of the blades 4 and 5, that is, the surfaces of the blades 4 on the subject side and the surfaces of the blades 5 on the image sensor side are not chamfered so that the blade surfaces can slide smoothly. The two directly moving blades 4 and 5 can be moved without disturbing the above.

  The diaphragm drive unit 1 and the drive arm 3 are arranged on the outer surface side of the base plate 2, and the blade drive pins 3 i and 3 j formed on the drive arm 3 are made to penetrate the base plate 2 and protrude to the inner surface side of the base plate 2. You may do it.

(Example 2)
A second embodiment of the present invention will be described with reference to FIG.

  The difference between the second embodiment and the first embodiment is that the number of blades, which are light shielding members that form the aperture, is four in the second embodiment compared to two in the first embodiment. Yes.

  The drive source is a motor 101, which is fixed to the main plate 102. A drive lever 103 is fixed to the output shaft of the motor 101, and rotates in conjunction with the rotation of the motor 101.

  The drive lever 103 has cylindrical convex portions 103a, 103b, 103c, and 103d, and can slide with the long hole portions 104a, 105a, 106a, and 107a of the blades 104, 105, 106, and 107, which are light shielding members, respectively. The blades 104, 105, 106, and 107 are moved in conjunction with the rotational position of the drive lever 103 by being engaged.

  At this time, the long holes 104b and 104c of the blade 104, the long holes 105b and 105c of the blade 105, the long holes 106b and 106c of the blade 106, and the long holes 107b and 107c of the blade 107 are slidable on the convex portions 102a and 102b of the base plate 102. Is retained. With this configuration, the blades 106 and 107 move in opposite directions with respect to the blades 104 and 105.

  In the first embodiment, there are two convex members for guiding the direction of sliding operation for each of the two blades, whereas in the second embodiment, all four blades are guided by the same convex member. However, this is a space issue and is not related to the number of blades. In the second embodiment, it is also possible to arrange two convex members at two locations, and there is no problem even if another guide method, for example, the operation direction is guided by using the outer peripheral portion of the blade. .

  In order to prevent the blades 104, 105, 106, and 107 from coming off from the convex portions 2a and 102b of the ground plate 102, the holding plate 108 is fixed to the ground plate 102 at a position that secures an operating space for the blades 104, 105, 106, and 107. .

Also in the second embodiment, as shown in the cross section of FIG. 1, the notches of the blades 10 4 to 107 are chamfered, and the blade 107 closer to the subject chamfers the surface on the subject side. The blade 104 on the side closer to the image sensor has chamfered the surface on the image sensor side.
Moreover, the light quantity adjusting device of the present invention is, for example,
In a diaphragm device or a shutter device that adjusts the amount of light reaching the imaging device by 2n (n = 1, 2, 3,...) Light shielding members that move in a direction substantially perpendicular to the optical axis,
Of the 2n light shielding members, the n light shielding members from the side closer to the imaging element are chamfered on the imaging element side of the portion forming the aperture, and the n light shielding members from the side closer to the subject have the aperture. The portion to be formed may be chamfered on the subject side.
Moreover, the light quantity adjusting device of the present invention is, for example,
In a diaphragm device or a shutter device that adjusts the amount of light reaching the imaging device by 2n + 1 (n = 1, 2, 3,...) Light-shielding members that move in a direction substantially perpendicular to the optical axis,
Of the 2n + 1 light shielding members, the n light shielding members from the side closer to the imaging element are chamfered on the imaging element side of the portion forming the aperture, and the n light shielding members from the side closer to the subject have the aperture. The object to be formed is chamfered on the subject side, and the middle piece of the light shielding member is chamfered on the part that forms the aperture on either the image sensor side or the subject side, or is not chamfered. This may be a feature.

DESCRIPTION OF SYMBOLS 1 Motor 2 Ground plate 3 Driving lever 4 Blade 5 Blade 6 Holding plate 7 Coil 101 Motor 102 Ground plate 103 Driving lever 104, 105, 106, 107 Blade 108 Holding plate

Claims (3)

By moving the optical axis and the straight direction orthogonal, and two light shielding member that adjusts the amount of light reaching the image sensor,
A drive unit for driving the two light shielding members,
By driving the plurality of light shielding members by the driving unit, the size of the aperture formed by the two light shielding members is adjusted,
The portions forming the apertures of the plurality of light shielding members are each chamfered on the surface opposite to the surface where the two light shielding members face each other in the direction of the optical axis. Light quantity adjustment device. By moving the optical axis and the straight direction orthogonal, a plurality of light shielding members for adjusting the amount of light reaching the image sensor,
A drive unit that drives the plurality of light shielding members,
By driving the plurality of light shielding members by the drive unit, said plurality of adjusting the size of the aperture formed by the light shielding member, the plurality of light blocking members, most diameter side of the light shielding member close to the image sensor light amount adjusting device, characterized in that the imaging element side of the portion to be formed, it is chamfered on both the object side of the part forming the diameter of the light shielding member closest on the subject side has been subjected to. An optical apparatus comprising the light amount adjusting device according to claim 1.

Images