JP2017138382A - Lens barrel and optical instrument using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel that suppresses a load originally unnecessary to be applied to a diaphragm mechanism in an optical axis direction when the diaphragm mechanism moves in the optical axis direction, and to provide an optical instrument that employs the lens barrel.SOLUTION: A lens barrel comprises: a plurality of diaphragm blades that is provided around an optical axis; a blade rotation member that includes a protrusion part protruding in a direction orthogonal to the optical axis, and is rotatable around the optical axis for moving the plurality of diaphragm blades in opening/closing directions; and a cam ring that includes a wall area where one part of the protrusion part slides as a first cam groove with respect to the protrusion part, and is rotatable around the optical axis for moving the plurality of diaphragm blades in the optical axis direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lens barrel having a light amount adjustment mechanism in which an opening area changes according to movement in an optical axis direction, and an optical apparatus using the lens barrel.

  An aperture that adjusts the amount of light in an optical device can change the area of the light passage aperture (diaphragm aperture diameter) by moving multiple aperture blades in the opening and closing direction. The aperture aperture diameter can be adjusted manually or manually by the user. Is set according to An actuator such as a stepping motor is used to move the aperture blade in the opening / closing direction.

  In addition, the optical device includes a main diaphragm that is configured as described above and mainly adjusts the amount of light, and a sub-aperture provided separately from the main diaphragm in order to correct the open aperture diameter according to zooming and focusing. May be installed. In the sub-aperture, similarly to the main aperture, the plurality of aperture blades are moved in the opening / closing direction. These sub-apertures may be driven by an opening / closing mechanism for opening / closing in accordance with zooming or focusing (Patent Document 1).

  In the optical device disclosed in Patent Document 1, a lens holding frame that holds a diaphragm mechanism as a light amount adjusting mechanism is cooperated with a cam portion provided on the cam barrel and a rectilinear guide portion provided on the rectilinear barrel. The structure that moves straight in the optical axis direction is adopted. A projection for changing the aperture diameter of the aperture is provided on the outer periphery of the aperture mechanism. The projection is engaged with an aperture driving cam provided on the inner surface of the fixed cylinder, and the aperture is opened according to the movement of the lens holding frame. It is an opening and closing mechanism that changes.

JP 2007-248770 A

  However, in the prior art disclosed in the above-mentioned patent document, when the movement amount of the lens holding frame holding the diaphragm mechanism is small, the angle α formed by the diaphragm driving cam portion and the optical axis orthogonal direction is small. It has the following problems. That is, as shown in FIG. 6A, for the drag N1 in the direction orthogonal to the angle α, the component in the optical axis direction (thrust direction) is larger than the component in the circumferential direction, so that the protrusion of the diaphragm mechanism rotates The force for moving in the optical axis direction is larger than the force for driving in the direction. In other words, since a load that is not originally required to be applied to the aperture mechanism is applied, there is a possibility that the operation failure or the opening accuracy may not satisfy the demand due to the load.

  An object of the present invention is to provide a lens barrel that suppresses a load in the optical axis direction that does not need to be originally applied to the aperture mechanism when the aperture mechanism moves in the optical axis direction, and an optical apparatus using the lens barrel. .

  In order to achieve the above object, a lens barrel according to the present invention includes a plurality of diaphragm blades provided around an optical axis and a protruding portion projecting in a direction orthogonal to the optical axis, and moves the plurality of diaphragm blades in an opening / closing direction. A blade rotating member rotatable around the optical axis and a wall region in which a part of the protruding portion slides as a first cam groove with respect to the protruding portion, and the plurality of aperture blades are arranged in the optical axis direction. And a cam ring rotatable around the optical axis for movement.

  An optical apparatus according to the present invention includes the lens barrel.

  According to the present invention, when the diaphragm mechanism moves in the optical axis direction, it is possible to provide a lens barrel that suppresses a load in the optical axis direction that does not need to be originally applied to the diaphragm mechanism, and an optical apparatus using the lens barrel. .

Sectional drawing of the lens-barrel which concerns on embodiment of this invention 1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention. 1 is an exploded perspective view of an aperture unit of a lens barrel according to an embodiment of the present invention. Front view and side view of aperture unit and main lens barrel The figure which shows the relationship between the position of the optical unit of the lens-barrel which concerns on embodiment of this invention, a sub aperture diameter, and a cam and a cam groove. (A) is an explanatory diagram of the thrust force applied to the sub-aperture arm when the angle α between the diaphragm driving cam portion and the optical axis orthogonal direction when the conventional cam groove is used, and (b), Explanatory drawing of the force applied to the sub-aperture arm in the lens barrel according to the embodiment of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< First Embodiment >>
(Lens barrel and optical equipment using it)
FIG. 1 is a cross-sectional view of a lens barrel according to an embodiment of the present invention. 2 is an exploded perspective view of the lens barrel shown in FIG. Here, the lens barrel 100 according to the present embodiment is mounted on a camera body 200 (equipped with an imaging device 300) that can be mounted on the lens barrel 100, and an optical apparatus such as an imaging device (digital camera, video camera, or the like). ) Can be configured. Hereinafter, the configuration of the lens barrel will be described with reference to FIG. 1 and FIG. 2. This lens barrel is used to operate an optical unit (lens unit) constituting an optical system and at least a part of the lens unit. It can be divided into two units called exterior units. A diaphragm unit 30 described later is included in the optical unit.

(Optical unit)
In FIG. 1, L1 is a first group lens, and includes a first lens L1A, a second lens L1B, a third lens L1C, and a fourth lens L1D. Reference numerals 1a to 1d denote lens holding frames that hold the lenses L1A to L1D, respectively. Of the first group lens L1, the third lens L1c is a camera shake correction lens for correcting camera shake. The lens holding frame 1c is supported by three balls (not shown) with respect to the lens holding frame 1d. It is movable in the direction perpendicular to the optical axis.

  The position and drive of the third lens L1C is driven by feedback control by a position detection sensor and an actuator (not shown) transmitting power and transmitting sensor output via a shift flexible printed circuit board (not shown). (So-called camera shake correction mechanism). Regardless of the control of the camera shake correction mechanism, all sensing and driving in the lens are controlled by the control board 66 (FIGS. 1 and 2). 1 and 2, the control board 66 can communicate with the camera side via the camera connector section 68, and commands from the camera are received by the control board 66 to control each drive section in the lens.

  The lens holding frame 1b is bonded and fixed to the support portion 1d-a of the lens holding frame 1d. The lens holding frame 1a and the lens holding frame 1d are screwed and fixed to the main barrel 40 holding the first group lens L1, the second group lens L2, and the third group lens L3 by the first group fixing screw 101. Accordingly, the first to fourth lenses L1A to L1D are formed as the first group lens L1.

  L2 is a two-group lens, and a 2a lens holding frame holding an L2A lens is bonded and fixed to a 2B lens holding frame holding an L2B lens, and is formed by these L2A and L2B lenses. The second group lens L2 is held on the main barrel 40 by a roller (not shown) provided on the lens holding frame L2B.

  L3 is a third group lens, which is a so-called focus lens that adjusts the focus position by moving in the optical axis direction. The third lens group L3 is held by the three-lens holding frame 3, and the three-lens holding frame 3 is held by two guide bars 43 (FIG. 2) so as to be movable in the optical axis direction. The two guide bars 43 are sandwiched between a main lens barrel 40 (FIG. 2) and a bar holder 42, and the bar holder 42 (FIG. 2) is fixed to the main lens barrel 40 with screws.

  A rack 45 (FIG. 2) is held on the three-lens holding frame 3, and a feed screw portion provided on a focus motor 47 (FIG. 2) fixed to the main barrel 40 with a focus motor fixing screw and a rack 45. It meshes with the provided tooth part. The focus motor 47 is a so-called stepping motor, which is supplied with power through the focus flex 49 (FIG. 2), rotates the feed screw, and converts the rotational force into thrust in the straight direction by meshing with the rack 45. The lens holding frame 3 is moved in the optical axis direction.

(Aperture unit)
Reference numeral 30 shown in FIG. 1 denotes an aperture unit. The aperture unit 30 will be described with reference to an exploded perspective view of the aperture unit in FIG. The diaphragm unit 30 is formed by a so-called main diaphragm section that changes Fno at the time of photographing and a sub diaphragm section that plays a role of cutting harmful light according to the position of the lens in the optical axis direction. The aperture unit 30 is fixed to the main lens barrel 40 (FIG. 2) by an aperture fixing screw 102 (FIG. 2).

  In FIG. 3, the boss portion of the sub-aperture blade 32 is engaged with the sub-aperture blade drive cam 31a provided on the sub-aperture blade drive member 31 as the blade rotation member. In the present embodiment, the sub diaphragm blade 32 is formed of seven blades. Reference numeral 33 denotes an aperture base, and 33a denotes a sub aperture blade holding hole that fits with a boss of the sub aperture blade 32 and holds the sub aperture blade 32 so that it can rotate at a fixed position. The sub diaphragm blade 32 is disposed in a space formed by the diaphragm base 33 and the sub diaphragm blade driving member 31, and the sub diaphragm driving member 31 is held so as to be rotatable about the optical axis center with respect to the diaphragm base 33.

  Reference numeral 31 b denotes a sub-aperture arm as an arm part that is a projecting part that projects in the direction orthogonal to the optical axis for driving the sub-aperture blade driving member 31. Although the driving method of the sub-aperture arm 31b will be described later, the sub-aperture driving member 31 is rotated by applying a force to the arm 31b. Further, harmful light is cut by moving the sub diaphragm blade 32 back and forth in the light beam of the lens (moving it in the optical axis direction) according to the positional relationship between the sub diaphragm blade driving cam 31a and the sub diaphragm blade holding hole 33a.

  Reference numeral 34 denotes a main diaphragm blade, which is formed of seven blades. Reference numeral 35 denotes a main diaphragm blade driving member, which is held by the diaphragm base 33 and the cover member 36 so as to be rotatable about the optical axis. The boss portion of the main diaphragm blade 34 is engaged with a main diaphragm blade driving cam 33 b provided on the diaphragm base 33 and a main diaphragm blade holding hole 35 a provided on the main diaphragm blade driving member 35.

  The main aperture blade driving member 35 is engaged with a pinion gear portion 37 a and a gear portion 36 b provided in the motor 37, and is driven to rotate by being supplied with power through the aperture FPC 38. By this rotational drive, the main diaphragm blade 34 enters the optical path, and the amount of light is adjusted by blocking the light. The configuration of the aperture unit 30 has been described above.

  FIG. 4 is a front view and a side view of a unit in which the aperture unit 30 is screwed to the main barrel 40. 4A is a front view of the sub diaphragm blade 32 in the opened state, FIG. 4B is a front view of the sub diaphragm blade 32 in the throttle state, and FIG. 4C is the arrow side of FIG. 4A. 4D is a side view seen from the arrow side of FIG. 4B.

  In the present embodiment, by providing a sub-aperture release spring 50 as an urging means for urging one of the rotation directions around the optical axis between the sub-aperture blade driving member 31 and the main lens barrel 40. The sub diaphragm blade driving member 31 is always urged to the open side. One end of the sub-aperture opening spring 50 is hooked on the spring holding portion 31 c of the sub-aperture blade driving member 31, and the other end is hooked on the spring holding portion 40 b of the main barrel 40.

  When squeezing the sub diaphragm blade 32, the sub diaphragm blade 32 can be squeezed by applying a load sufficient to overcome the sub diaphragm opening spring 50 to the sub diaphragm arm 31b. Needless to say, when the application of the load is stopped, the sub diaphragm blade 32 is opened by the sub diaphragm opening spring 50.

  Returning to FIG. 2, reference numeral 21 denotes a filter frame that forms the appearance of the lens barrel. The filter frame 21 is fixed to the main lens barrel 40 with screws after the first to third lens groups L1 to L3 and the like described so far are incorporated into the main lens barrel 40. Thus, the lens barrel is completed.

(Exterior unit)
Next, the exterior unit will be described. In FIGS. 1 and 2, reference numeral 61 denotes a manual focus operation ring (operation ring), which is sandwiched between a front holding ring (holding ring) 60 and a fixed cylinder 65 so as to be rotatable around the optical axis. When the operation ring 61 rotates, the comb-tooth portions 61a provided at equal intervals on the operation ring 61 switch between light projection and light shielding of the two rotation detection photo interrupters (photo interrupters) 62a held by the fixed cylinder 65. The rotation direction and rotation speed of the operation ring 61 are detected. The photo interrupter 62 is solder-mounted on a manual focus flexible printed circuit board (MF-FPC) 62b.

  The photo interrupter 62a as a rotation detecting element and the MF-FPC 62b for transmitting a signal detected by the photo interrupter 62a function as a rotation detecting means. Then, the output of the photo interrupter 62a is transmitted to the control board 66 via the MF-FPC 62b, and the focus motor 47 is powered and driven based on the information, thereby enabling manual focus.

  In FIGS. 1 and 2, reference numeral 64 denotes a position ring, which is rotatably held by a fixed cylinder 65. As shown in FIG. 1, the position ring 64 is formed of a cam ring 64c provided with a cam groove for moving the optical unit in the optical axis direction, and a first exterior 64a and a second exterior 64b that form the exterior. Has been. Here, the first exterior 64a and the second exterior 64b are bonded and fixed to the cam ring 64c (FIG. 1).

  In FIGS. 1 and 2, reference numeral 66 denotes a control board that controls a lens barrel such as a focus motor, a camera shake correction mechanism, and a diaphragm unit. The control board 66 performs various controls by communicating with the camera via the camera connector section 68 fixed to the mount 4 (FIG. 1) by the camera connector section fixing screw 105 (FIG. 2). The control board 66 is fixed to the fixed cylinder 65.

  In FIGS. 1 and 2, reference numeral 67 denotes an exterior cylinder, which is a part of the appearance of the product. The outer cylinder 67 is sandwiched between the fixed cylinder 65 and the mount 4 and is fixed by a mount fixing screw 106 (FIG. 2). The above is the configuration of the exterior unit.

(Optical unit and sub-aperture drive)
Hereinafter, first, driving of the optical unit will be described. The lens barrel has three positions: a storage position for improving portability, a normal shooting position where focusing can be performed from infinity to the closest position, and a macro shooting position enabling macro shooting.

  For the optical unit, the three cam pins 40a provided on the main barrel 40 are divided into three rectilinear guide grooves 65a provided on the fixed barrel 65 and three main cam grooves 64c-a provided on the cam ring 64c. Is engaged. Then, by rotating the position ring 64, the optical unit is moved in the optical axis direction. In the present embodiment, the position where the position ring 64 is rotated by 30 ° from the storage position is the normal photographing position. Further, the position where the 14 ° position ring 64 is rotated becomes the macro photographing position. Note that the storage position, the storage position to the normal shooting position, and the normal shooting position and the macro shooting position are non-shooting areas.

  FIG. 5 is a diagram showing the relationship between the position of the optical unit, the sub aperture diameter, and the cam and cam groove. FIG. 5A shows the storage position, and the optical unit is housed in the exterior unit in order to improve portability. At this time, the sub-aperture is in an open state. FIG. 5B shows a normal photographing position. In this configuration, when the position ring 64 is rotated by 30 ° to move from the housed state to the normal photographing state, the optical unit extends about 19 mm. At this position, it is possible to focus from infinity to close. The sub-aperture is also open at this position.

  FIG. 5D shows a macro shooting position. In this configuration, when the position ring 64 is rotated by 14 ° from the normal shooting position, a lens of about 0.6 mm is extended to enable macro shooting. At the macro photographing position, the sub-aperture is in a narrowed state in order to block harmful light incident by extending the lens.

  Here, regarding the driving of the optical unit and the sub-aperture, the relationship between the cam pin 40a, the sub-aperture arm 31b, and each cam groove will be described with reference to FIG. The cam pin 40a is engaged with the cam groove in all the regions of FIGS. 5A to 5D, and changes the position of the optical unit in the optical axis direction. At this time, of course, the sub-aperture arm 31b also moves in the optical axis direction.

  However, the sub-aperture arm 31b is in a non-contact state (non-sliding state) with respect to the sub-aperture cam groove 64c-b from FIGS. 5A to 5C, and is in an unloaded state in both the optical axis direction and the rotation direction. It has become. 5C, the sub-aperture arm 31b and the sub-aperture drive wall 64c-d, which is a wall region (wall surface) along the optical axis direction, as a part of the cam groove 64c-b abut. .

  While the position ring 64 from FIGS. 5B to 5C is rotated by 4 ° (a region different from the sub-throttle drive wall 64c-d), the sub-throttle arm 31b has the cam groove 64c-b as described above. However, the cam groove 64c-b is not in contact. As a result, in this state, both the optical axis direction and the rotational direction are unloaded, and the sub-aperture moves in the optical axis direction from FIGS. 5 (a) to 5 (b). The caliber does not change.

  In the position of FIG. 5C, the contact portion between the sub-aperture arm 31b and the sub-aperture drive wall 64c-d is slidably contacted in the optical axis direction. 5 (c) to 5 (d), the position ring 64 is rotated by 10 °, and the sub diaphragm is stopped by rotating the sub diaphragm arm 31b in the rotation direction by the sub diaphragm driving wall 64c-d. That is, in the state from FIG. 5A to FIG. 5B (the state where the protruding portion is not slid on the wall region), only the elastic force by the above-described opening spring 50 is applied to the sub-throttle arm 31b. It is open because it is working.

  On the other hand, as shown in FIGS. 5C to 5D, the sub diaphragm moves in the optical axis direction while the sub diaphragm arm 31b is in contact with the sub diaphragm drive wall 64c-d. The above force is applied to the sub-throttle arm 31b. As a result, the aperture diameter changes so that the sub-aperture is reduced.

  At this time, the optical unit moves in the thrust direction (optical axis direction) and the sub-aperture arm 31b also moves in the thrust direction, but the thrust force applied to the sub-aperture arm 31b is between the sub-aperture drive walls 64c-d. It is only the frictional force M that works (proportional to the drag force N2 in FIG. 6B). Therefore, even when the amount of movement of the optical unit in the thrust direction is small as in this lens configuration, the force applied to the sub-aperture arm 31b is a frictional force M acting between the sub-aperture arm 31b and the sub-aperture drive walls 64c-d. (FIG. 6B) only.

  As a result, the force in the thrust direction (optical axis direction) becomes very small, and the load in the thrust direction (optical axis direction) that does not need to be applied can be suppressed. That is, in this embodiment, since the rotation of the sub-throttle mechanism due to the deformation of the sub-throttle arm 31b and the force that impedes the driving of the mechanism are suppressed to a small level, a stable operation mechanism and high aperture diameter accuracy can be maintained. Is possible. In this way, since the load in the optical axis direction when the aperture is opened and closed is greatly suppressed, it is possible to form an opening / closing mechanism with good operation and an accurate opening.

(Modification)
As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and change are possible within the range of the summary.

(Modification 1)
In the embodiment described above, the wall region 64c-d on which a part of the projecting portion (the tip of the sub-aperture arm 31b) slides is provided in the optical axis direction, but is inclined in the optical axis direction (for example, the optical axis direction). May be provided in a direction within 30 degrees with respect to.

(Modification 2)
In the above-described embodiment, the case where the camera body having the imaging element is provided and the camera body is applied to an imaging device (imaging device) as an optical device that can be attached to the lens barrel has been described. Not limited. For example, the present invention can be applied to a projector as an optical device including an image display element and a lens barrel for enlarged projection.

31 .. Sub-throttle blade drive member, 31 b .. Sub-throttle arm, 32 .. Sub-throttle blade, 64 c .. Cam ring, 64 c-b .. Cam groove, 64 c-d.

Claims (10)

A plurality of diaphragm blades provided around the optical axis;
A blade rotating member that includes a protruding portion that protrudes in a direction orthogonal to the optical axis, and that can rotate around the optical axis to move the plurality of diaphragm blades in the opening and closing direction;
A cam ring that includes a wall region in which a part of the protruding portion slides as a first cam groove with respect to the protruding portion, and is rotatable around the optical axis in order to move the plurality of aperture blades in the optical axis direction;
A lens barrel comprising: The wall region is part of the first cam groove;
The diaphragm aperture diameters of the plurality of diaphragm blades change as a part of the protrusion slides on the wall region.
The lens barrel according to claim 1. In a state where a part of the protrusion does not slide on the wall region, the aperture diameter of the diaphragm does not change.
The lens barrel according to claim 2.   The lens barrel according to claim 1, wherein the wall region is provided in the optical axis direction.   5. The part according to claim 1, wherein a part of the protruding portion does not slide into the first cam groove in a region different from the wall region in the first cam groove. Lens barrel. Having a lens unit,
6. The lens barrel according to claim 1, wherein the cam ring includes a second cam groove that moves at least a part of the lens unit in the optical axis direction.   7. The lens barrel according to claim 1, further comprising an urging unit that urges the blade rotating member in any one of rotational directions around the optical axis. With an image sensor
An optical apparatus that can be attached to the lens barrel according to claim 1. A camera body including the image sensor;
The optical apparatus according to claim 8, wherein the camera body can be attached to the lens barrel. An image display element;
The lens barrel according to any one of claims 1 to 7,
An optical apparatus comprising: