JP2005309030A - Lens device and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the arm portion of a spring member for driving a barrier member from being greatly displaced in the optical axis direction while simplifying the lens device.
A barrier member (4, 5) for opening and closing a front surface of a photographing optical system, a fixing member (1), a rotating member (2) rotatable around an optical axis with respect to the fixing member, and an arm ( 6a, 6b, 7a, 7b) and a spring member (6, 7) attached to the barrier member. The rotating member drives the barrier member by pushing the arm portion by a rotating operation, and the fixing member has a limiting portion (1b, 1c) that restricts displacement of the arm portion pushed by the rotating member in the optical axis direction.
[Selection] Figure 1

Description

  The present invention relates to a lens device including a barrier member capable of opening and closing a front surface of a photographing optical system, and a camera having the lens device.

  The conventional barrier device has two barrier blades that cover the front surface of the photographing optical system, and a barrier drive ring that rotates around the optical axis to open and close the barrier blades (see, for example, Patent Document 1). . Here, a barrier spring is disposed between the barrier blade and the barrier drive ring, and the barrier spring biases the barrier blade in the closing direction and allows the barrier drive ring to move away from the barrier blade.

  A barrier drive spring is disposed between the barrier drive ring and the lens barrel cover, and the barrier drive spring urges the barrier drive ring in one direction around the optical axis to drive the barrier blades in the opening direction. Further, the conventional barrier device has a coupling mechanism that transmits the rotational force of the rotary cylinder provided in the lens barrel to the barrier drive ring.

  The operation of the barrier device configured as described above will be described. When the rotating cylinder rotates clockwise (in the other direction around the optical axis), the rotational force of the rotating cylinder is transmitted to the barrier driving ring via the coupling mechanism, and the barrier driving ring rotates clockwise while charging the barrier driving spring. . Then, according to the rotation of the barrier drive ring, the barrier blade rotates around the base end side to cover the front surface of the photographing optical system (closing operation).

  When the rotating cylinder rotates counterclockwise (one direction around the optical axis), the barrier drive ring rotates counterclockwise by the spring force of the charged barrier drive spring. Then, the barrier blade rotates about the base end side in accordance with the rotation of the barrier drive ring and retracts from the front surface of the photographing optical system (opening operation).

Here, when the barrier blade cannot be rotated in the closing direction by some obstacle (for example, foreign matter such as sand) during the closing operation, the barrier driving ring is charged to allow the barrier driving ring to rotate in the clockwise direction. . That is, the barrier spring allows the barrier drive ring to move away from the barrier blade.
JP-A-7-159856 (paragraph numbers 0010, 0014 to 0016, FIG. 1)

  However, the barrier device proposed in Patent Document 1 described above requires a dedicated component for driving the barrier blades to open and close, that is, the connecting mechanism described above. Moreover, when the barrier blade cannot be rotated in the closing direction due to some obstacle (for example, foreign matter such as sand) during the closing operation of the barrier blade, a dedicated component that allows the barrier drive ring to move away from the barrier blade, that is, the barrier described above. A spring is required.

  Thus, the need for the dedicated parts described above increases the cost of the barrier device due to an increase in the number of parts. In addition, since a space for arranging dedicated parts must be secured, the barrier device and the lens barrel on which the barrier device is mounted are increased in size.

  On the other hand, while taking measures to prevent the operation of the barrier blades from being obstructed by obstacles, for example, while increasing the spring force of the barrier drive spring and considering the spring balance of the barrier drive spring and the barrier spring, the barrier blade is closed. The driving load of the barrier drive ring during operation increases. That is, the driving force of the rotating cylinder for rotating the barrier driving ring must be increased, and the power consumption of the lens barrel (camera) increases.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens device in which a barrier blade driving mechanism has a simple configuration in order to solve the above-described problems.

  The lens device of the present invention has a barrier member that opens and closes the front surface of the photographing optical system, a fixing member, a rotating member that can rotate around the optical axis with respect to the fixing member, and an arm portion, and is attached to the barrier member. And a spring member. Here, the rotating member drives the barrier member by pushing the arm portion by a rotating operation, and the fixing member has a limiting portion that restricts displacement of the arm portion pushed by the rotating member in the optical axis direction. And

  According to the present invention, since the rotating member pushes the arm portion of the spring member to drive the barrier member, the barrier member can be driven with a simple configuration. Moreover, the barrier member can be driven smoothly by limiting the displacement of the arm portion pressed by the rotating member in the optical axis direction.

  Examples of the present invention will be described below.

  A camera that is Embodiment 1 of the present invention will be described with reference to FIGS.

  First, the configuration of the camera of this embodiment will be described with reference to FIG. FIG. 15 is an external perspective view of the camera of this embodiment.

  In FIG. 15, reference numeral 100 denotes a camera body, and a member 100 a for enabling photographing is disposed inside the camera body. For example, in the case of a silver salt camera, a photographing aperture (aperture) and film, and in the case of a digital camera, an image sensor that photoelectrically converts an optical image formed by a photographing optical system into an electrical signal is disposed. A lens barrel 101 is provided on the front surface of the camera body 100, and includes a lens, a light amount adjusting member (shutter and diaphragm), and the like as will be described later. A barrier unit 20 described later is disposed at the tip of the lens barrel 101.

  The lens barrel 101 is housed in the camera body 100 and is in a retracted state when not photographing. On the other hand, at the time of photographing, the lens barrel 101 is extended from the retracted state in the optical axis direction (FIG. 15).

  A release button 102 is operated to start a shooting preparation operation (photometry operation and a focus adjustment operation) and a shooting operation, and 103 is an optical viewfinder for observing the subject. Reference numeral 104 denotes a photometric unit for measuring the luminance of the subject, and reference numeral 105 denotes an illumination unit that irradiates illumination light toward the subject.

  Next, the configuration of the lens barrel 101 will be described with reference to FIG. FIG. 14 is a cross-sectional view of the lens barrel of the present embodiment.

  The fixed cylinder 25 is fixed to the camera body 100. A helicoid part is formed on the outer peripheral surface of the third rotating cylinder 23, and the helicoid part is engaged with a helicoid part formed on the inner peripheral surface of the fixed cylinder 25. Here, when the driving force of a driving source (not shown) disposed in the camera body 100 is transmitted to the third rotating cylinder 23 via a power transmission mechanism (not shown), the third rotating cylinder 23 is moved to the optical axis. It moves in the direction of the optical axis while rotating around. Inside the third rotating cylinder 23, a third rectilinear cylinder 24 that moves only in the optical axis direction together with the third rotating cylinder 23 without being rotated around the optical axis is disposed.

  The second rotating cylinder 21 rotates around the optical axis according to the rotation of the third rotating cylinder 23. A helicoid part is formed on the outer peripheral surface of the second rotating cylinder 21, and the helicoid part is engaged with a helicoid part formed on the inner peripheral surface of the third rectilinear cylinder 24. For this reason, the second rotating cylinder 21 receives the rotational force from the third rotating cylinder 23 and moves in the optical axis direction while rotating around the optical axis with respect to the third rectilinear cylinder 24.

  A second rectilinear cylinder 22 is disposed inside the second rotating cylinder 21, and the second rotating cylinder 21 is engaged with the second rectilinear cylinder 22 so as to be slidable around the optical axis. Since the second rectilinear cylinder 22 is engaged with a groove formed in the third rectilinear cylinder 24 extending in the optical axis direction, the second rectilinear cylinder 22 does not rotate around the optical axis but only in the optical axis direction together with the second rotary cylinder 21. Moving.

  The first rectilinear cylinder (fixing member) 1 is movable only in the optical axis direction by engagement with the second rectilinear cylinder 22. A helicoid portion 1 d is formed on the outer periphery of the first rectilinear cylinder 1, and the helicoid portion 1 d is engaged with a helicoid portion 21 a formed on the inner periphery of the second rotating cylinder 21. For this reason, when the second rotating cylinder 21 rotates around the optical axis, the first rectilinear cylinder 1 moves in the optical axis direction with respect to the second rotating cylinder 21 (second rectilinear cylinder 22).

  A convex portion 2 a is formed on the outer peripheral surface of the first rotary cylinder (rotating member) 2, and the convex portion 2 a engages with a guide key (a groove extending in the optical axis direction) formed on the second rotary cylinder 21. doing. For this reason, the first rotating cylinder 2 receives the rotational force of the second rotating cylinder 21 and rotates around the optical axis.

  The first rotating cylinder 2 is engaged with the first rectilinear cylinder 1 so as to be slidable around the optical axis, and is movable together with the first rectilinear cylinder 1 in the optical axis direction. .

  On the other hand, in the lens barrel 101, a first lens group 3, a second lens group 31, a shutter unit 32, a third lens group 33, and a fourth lens group 34 are arranged in this order from the object side (left side in FIG. 14). Has been.

  Next, the configuration and operation of the front end side (object side) of the lens barrel 101, particularly the configuration and operation of the barrier unit will be described with reference to FIGS.

  1 is an exploded perspective view showing the configuration of the barrier unit, FIG. 2 is an external perspective view of a barrier blade incorporating a barrier spring, FIG. 3 is a perspective view showing the relationship between the rotating cylinder and the barrier spring, and FIG. It is a front view of the barrier unit in a state.

  5 is a front view of the barrier unit in a half-open state, FIG. 6 is a front view of the barrier unit in a state immediately before full opening, FIG. 7 is a partially enlarged view of the barrier unit shown in FIG. 6, and FIG. FIG. 9 is a partially enlarged view of the barrier unit shown in FIG.

  10 is a front view of the barrier unit in a state where the barrier blade starts to close, FIG. 11 is a front view of the barrier unit in a state where the barrier blade is forcibly opened, and FIG. 12 is a state in which the closing operation of the barrier blade is prevented FIG. 13 is a front view of the barrier unit in a state where the opening operation of the barrier blades is blocked.

  The first rectilinear cylinder 1 includes an opening 1a that supports the first lens group 3 that is a part of the photographing optical system, and elastic transmission arms 6a and 6b of barrier springs (spring members) 6 and 7, as will be described later. , 7a, 7b are formed with protrusions 1b, 1c having spaces (recesses 1b1, 1c1). Here, the convex portions 1 b and 1 c are formed on the end surface of the first rectilinear cylinder 1 on the tip side (subject side). The first lens group 3 is located closest to the object side in the photographic optical system.

  On the inner peripheral surface of the first rotating cylinder 2, a protrusion 2g for driving the barrier blade 4 in contact with elastic transmission arms 6a and 6b of a barrier spring 6 to be described later is formed. On both sides of the protrusion 2g in the circumferential direction of the first rotating cylinder 2, there are provided a first groove 2b and a second groove 2d for securing a moving space for the barrier spring 6 (elastic transmission arm portions 6a, 6b). It has been. These groove portions 2 b and 2 d extend in the circumferential direction of the first rotating cylinder 2.

  Although not shown in FIGS. 1 to 3, an elastic transmission arm of a barrier spring 7, which will be described later, is located on the inner peripheral surface of the first rotating cylinder 2 so as to face the protrusion 2 g across the optical axis. Projections 2h for driving the barrier blades 5 in contact with the portions 7a and 7b are formed (see FIG. 4 and the like). Then, on both sides of the protrusion 2h in the circumferential direction of the first rotating cylinder 2, a third groove 2c (first groove 2b) for securing a moving space for the barrier spring 7 (elastic transmission arm portions 7a, 7b) is provided. And a fourth groove 2e (corresponding to the second groove 2d).

  Reference numerals 4, 5, 9, and 10 denote barrier blades (barrier members) operable between a fully closed position covering the front surface of the first lens group 3 and a fully open position retracted from the front surface of the first lens group 3. . Each barrier blade engages with a support shaft (not shown) provided on the back surface of the barrier cover 8 and extending in the optical axis direction at the base end portion, and rotates around the support shaft. That is, the barrier blades 4, 5, 9, 10 (hereinafter referred to as barrier blades 4 to 10) rotate in a plane orthogonal to the photographing optical axis.

  Here, the holes 5d and 10a formed in the barrier blades 5 and 10 are engaged with the same support shaft 8b, and the holes 4d and 9a formed in the barrier blades 4 and 9 are the same support shaft (not shown). ) Is engaged. The barrier blades 4 and 5 are formed in the same shape, and the barrier blades 9 and 10 are formed in the same shape.

  Reference numerals 6 and 7 denote barrier springs that open and close the barrier blades 4 and 5 according to the rotation of the first rotating cylinder 2 as described later. The barrier springs 6 and 7 are greatly elastically deformed to allow the operation of one of the first rotating cylinder 2 and the barrier blades 4 and 5 as will be described later. Yes.

  As shown in FIG. 2, the barrier spring 6 has a coil portion 6c formed by winding a wire, and two elastic transmission arm portions 6a and 6b formed in a substantially U shape at both ends thereof. ing. The barrier spring 6 is attached to the barrier blade 4 by engaging the coil portion 6 c with the rotation center portion 4 a of the barrier blade 4. Here, the elastic transmission arm portions 6 a and 6 b engage with the groove portions 4 b 1 and 4 b 2 formed in the barrier blade 4.

  Further, the barrier spring 6 is arranged so that the elastic transmission arm portions 6 a and 6 b are positioned on both sides of the protruding portion 2 g of the fixed cylinder 2 as shown in FIG. 3. At this time, the elastic transmission arm portion 6a is located in the first groove portion 2b of the first rotary cylinder 2, and the elastic transmission arm portion 6b is located in the second groove portion 2d. Here, since the elastic transmission arm portions 6a and 6b are located at both ends of the coil portion 6c, the groove portions 2b and 2d are formed at different positions according to the positions of the elastic transmission arm portions 6a and 6b. . That is, the surface including the first groove 2b (surface orthogonal to the optical axis) and the surface including the second groove 2d (surface orthogonal to the optical axis) are at different positions in the optical axis direction.

  In the above configuration, when the first rotating cylinder 2 rotates around the optical axis, the protrusion 2g of the first rotating cylinder 2 pushes one of the elastic transmission arm portions 6a and 6b to rotate the barrier spring 6. At this time, the one elastic transmission arm is elastically deformed by a predetermined amount upon being pushed by the protrusion 2g.

  Since the elastic transmission arm portions 6a and 6b are engaged with the groove portions 4b1 and 4b2 with the barrier blade 4 sandwiched therebetween, one elastic transmission arm portion of the elastic transmission arm portions 6a and 6b is the first rotating cylinder 2. When the protrusion 2g is pushed in, the other elastic transmission arm pushes the barrier blade 4 to rotate the barrier member 4. That is, the barrier blade 4 rotates together with the barrier spring 6 that receives the rotational force from the first rotating cylinder 2.

  On the other hand, the barrier spring 7 is formed in the same shape as the barrier spring 6 and is attached to the barrier blade 5. That is, as shown in FIG. 2, the barrier spring 7 includes a coil portion 7c formed by winding a wire, and two elastic transmission arm portions 7a and 7b formed in a substantially U shape at both ends. Have. The barrier spring 7 is attached to the barrier blade 5 by engaging the coil portion 7 c with the rotation center portion 5 a of the barrier blade 5. At this time, the elastic transmission arm portions 7 a and 7 b are engaged with the groove portions 5 b 1 and 5 b 2 formed in the barrier blade 5.

  The barrier spring 7 is arranged so that the elastic transmission arm portions 7 a and 7 b are positioned on both sides of the protrusion 2 h of the fixed cylinder 2. At this time, the elastic transmission arm portion 7a is located in the third groove portion 2c of the first rotating cylinder 2, and the elastic transmission arm portion 7b is located in the fourth groove portion 2e (see FIG. 4 and the like).

  In the above configuration, when the first rotating cylinder 2 rotates around the optical axis, the protrusion 2h of the first rotating cylinder 2 pushes one of the elastic transmission arm portions 7a and 7b to rotate the barrier spring 7. At this time, the one elastic transmission arm portion is elastically deformed by a predetermined amount in response to the pushing of the protrusion 2h.

  Since the elastic transmission arm portions 7a and 7b are engaged with the grooves 5b1 and 5b2 with the barrier blade 5 interposed therebetween, one of the elastic transmission arm portions 7a and 7b is pushed in by the protrusion 2h. Then, the other elastic transmission arm portion pushes the barrier blade 5 to rotate the barrier blade 5. That is, the barrier blade 5 rotates together with the barrier spring 7 that receives the rotational force from the first rotating cylinder 2.

  Reference numerals 8 and 11 denote a barrier cover and a barrier plate, respectively, which are fixed to the first rectilinear cylinder 1 with the barrier blades 4 to 10 interposed therebetween. The barrier cover 8 is located on the subject side with respect to the barrier blades 4 to 10, and the barrier plate 11 is located on the image plane side with respect to the barrier blades 4 to 10. In addition, the barrier unit 20 mentioned above is comprised by the barrier cover 8, the barrier plate 11, and the barrier blades 4-10.

  Each of the barrier cover 8 and the barrier plate 11 is formed with openings 8a and 11a for allowing subject light to pass therethrough. The barrier plate 11 is formed with holes 11b (the remaining one is not shown) that engages with the rotation center portions 4a and 5a of the barrier blades 4 and 5.

  The barrier blades 4 to 10 enter or retreat from the optical path between the openings 8a and 11a by the rotation operation described above. The barrier blades 4 to 10 in a state of entering the optical path (a fully closed state described later) suppress the incidence of subject light into the lens barrel 101. Further, the barrier blades 4 to 10 in a state of being retracted from the optical path (a fully opened state described later) allow the object light to enter the lens barrel 101.

  Next, the opening and closing operation of the barrier blades 4 to 10 will be specifically described with reference to FIGS. 4 to 10 show a state where the barrier cover 8 is removed.

(1) When the barrier blades are fully opened When a main switch (not shown) of the camera body 100 is turned on, a motor (not shown) provided in the camera body 100 is driven. Here, when the main switch is in the OFF state, the barrier unit is in the state shown in FIG. 4, and the barrier blades 4 to 10 close the front surface of the first lens group 3 (fully closed state).

  The driving force of the motor is transmitted to the first rotating cylinder 2 via the power transmission mechanism or the like as described above, and the first rotating cylinder 2 rotates in the direction of arrow A (one direction around the optical axis) in FIG. Thereby, the protrusion 2g of the first rotating cylinder 2 contacts the elastic transmission arm 6a of the barrier spring 6 on the side surface 2g1 on the first groove 2b side. In addition, the protrusion 2h of the first rotating cylinder 2 contacts the elastic transmission arm 7a of the barrier spring 7 on the side surface 2h1 on the third groove 2c side.

  As a result, the first rotary cylinder 2 and the barrier springs 6 and 7 are interlocked, and the rotational force of the first rotary cylinder 2 is transmitted to the barrier springs 6 and 7. That is, according to the rotation of the first rotating cylinder 2, the barrier spring 6 rotates and the barrier blade 4 rotates in the opening direction. Further, the barrier spring 7 rotates in accordance with the rotation of the first rotating cylinder 2 and the barrier blade 5 rotates in the opening direction.

  When the barrier blades 4 and 5 are rotated by a predetermined amount in the opening direction, the side edge of the barrier blade 4 abuts on the convex portion 9c provided on the barrier blade 9, and the side edge of the barrier blade 5 is provided on the barrier blade 10. It abuts against the raised projection 10c (see FIG. 5). At this time, the barrier unit is in a half-open state.

  When the barrier unit in the half-open state is viewed from the subject side, the barrier blade 4 is positioned so as to be generally within the area of the barrier blade 9, as shown in FIG. It is located so as to fit in.

  When the first rotating cylinder 2 rotates in the arrow A direction from the state shown in FIG. 5, the barrier blade 4 rotates in the opening direction together with the barrier blade 9, and the barrier blade 5 rotates in the opening direction together with the barrier blade 10.

  In this embodiment, the barrier blades are composed of four sheets, and the barrier blades 4 and 9 and the barrier blades 5 and 10 are retreated from the optical path between the openings 8a and 11a in a state where they are overlapped in the optical axis direction. ing. For this reason, the retraction space (space in the direction perpendicular to the optical axis) of the barrier blades can be reduced as compared with the case where two barrier blades are configured, and the lens barrel 101 can be downsized in the radial direction.

  When the barrier blades 4 and 9 are integrally rotated in the opening direction, the contact state of the elastic transmission arm portion 6a with the protrusion 2g is changed by the rotation of the barrier spring 6 accompanying the rotation of the first rotating cylinder 2. That is, the elastic transmission arm portion 6a of the barrier spring 6 is pushed into the protrusion 2g of the first rotating cylinder 2 and enters the radially inner side of the first rotating cylinder 2 as shown in FIGS.

  At this time, the elastic transmission arm portion 6a enters the recess (restriction portion) 1b1 provided in the first rectilinear cylinder 1 as shown in FIGS. That is, the first groove 2b and the recess 1b1 are in the same plane orthogonal to the optical axis, and when the elastic transmission arm 6a is displaced radially inward of the first rotating cylinder 2 and disengages from the first groove 2b. It is configured to enter the recess 1b1.

  On the other hand, the barrier spring 7 performs the same operation as that of the barrier spring 6 described above. That is, when the barrier blades 5 and 10 in the state shown in FIG. 5 are integrally rotated in the opening direction, the elastic transmission arm portion 7a of the barrier spring 7 is pushed into the protrusion 2h of the first rotating cylinder 2. It enters the radially inner side of the first rotating cylinder 2. At this time, the elastic transmission arm portion 7a is disengaged from the third groove portion 2c and enters the recess (restriction portion) 1c1 provided in the first rectilinear cylinder 1.

  When the elastic transmission arm portions 6a and 7a are disengaged from the groove portions 2b and 2c, the first rotary cylinder 2 and the barrier springs 6 and 7 are brought into an unlinked state, and the rotational force of the first rotary cylinder 2 is transmitted to the barrier springs 6 and 7. Disappear. And only the 1st rotation cylinder 2 rotates, and a barrier unit will be in a fully open state, as shown in FIG.

  When in the state shown in FIG. 8, the elastic transmission arm portion 6a is in contact with the inner peripheral surface 2f of the first rotating cylinder 2 in a state of entering the recess 1b1 as shown in FIG. When the elastic transmission arm portion 6a abuts against the inner peripheral surface 2f of the first rotating cylinder 2, the barrier spring 6 is held in the state shown in FIGS. 8 and 9, and the barrier blades 4 and 9 are held in the fully opened state. . The same applies to the barrier spring 7, and the barrier blades 5 and 10 are held in a fully opened state.

  Here, when the barrier unit is in the state shown in FIG. 8, the lens barrel 101 is in the photographing state by stopping the driving of the motor.

(2) When the barrier blade is fully closed When the main switch of the camera body is switched from the ON state to the OFF state, a motor (not shown) is driven. By driving the motor, the first rotating cylinder 2 rotates in the direction of arrow B (the other direction around the optical axis) from the state shown in FIG.

  Thereby, as shown in FIG. 10, the protrusion 2g of the first rotating cylinder 2 contacts the elastic transmission arm 6b of the barrier spring 6 on the side surface 2g2 on the second groove 2d side. Further, the protrusion 2h of the first rotating cylinder 2 contacts the elastic transmission arm portion 7b of the barrier spring 7 on the side surface 2h2 on the fourth groove 2e side.

  The elastic transmission arm portions 6a and 7a slide on the inner peripheral surface 2f of the first rotating cylinder 2 until the protrusions 2g and 2h contact the elastic transmission arm portions 6b and 7b from the state shown in FIG. become. Here, the elastic transmission arm portions 6a and 7a are formed in a substantially U shape as described above, and are in contact with the inner peripheral surface 2f of the first rotating cylinder 2 at a portion having a curved surface. The one-turn cylinder 2 can rotate smoothly. In addition, the shape of the elastic transmission arm portions 6a and 7a of the barrier springs 6 and 7 is not limited to the shape described above. That is, if the elastic transmission arm portion has a curved surface (bending portion) and is brought into contact with the inner peripheral surface of the first rotating cylinder 2 with the curved surface, the first rotating cylinder 2 can be smoothly rotated. Further, a lubricant or the like that reduces friction may be applied to a portion of the inner peripheral surface of the first rotating cylinder 2 that comes into contact with the elastic transmission arm portion.

  The protrusions 2g and 2h are brought into contact with the elastic transmission arms 6b and 7b, whereby the first rotating cylinder 2 and the barrier springs 6 and 7 are interlocked, and the rotational force of the first rotating cylinder 2 is applied to the barrier springs 6 and 7. Communicated. At this time, the elastic transmission arm portions 6a and 7a are detached from the inner peripheral surface 2f of the first rotating cylinder 2 and enter the first groove portion 2b and the third groove portion 2c.

  When the first rotating cylinder 2 rotates in the arrow B direction from the state shown in FIG. 10, the barrier springs 6 and 7 and the barrier blades 4 to 10 follow the operation that is substantially opposite to the above-described opening operation, and is fully closed as shown in FIG. It becomes a state.

  That is, when the first rotating cylinder 2 rotates in the arrow B direction from the state shown in FIG. 10, the barrier blade 4 and the barrier spring 6 rotate together in the closing direction, and the barrier blade 5 and the barrier spring 7 integrate together. And rotate in the closing direction. Thereby, the closing operation of the barrier blades 4 and 5 is started, and when the barrier blades 4 and 5 rotate by a predetermined amount in the closing direction, the convex portions 4c and 5c provided on the barrier blades 4 and 5 become the barrier blades 9 and 10 respectively. It abuts on the formed notches 9b and 10b.

  Thereafter, the barrier blades 4 and 9 are integrally rotated in the closing direction, and the barrier blades 5 and 10 are integrally rotated in the closing direction. And the barrier blades 4-10 will be in the fully closed state shown in FIG. At this time, the lens barrel 101 is retracted from the photographing state in the optical axis direction to be in the retracted state.

  In the above-described closing operation of the barrier blades 4 to 10, the elastic transmission arm portion 6 a of the barrier spring 6 is retracted from the concave portion 1 b 1 provided in the first rectilinear cylinder 1 and the first groove portion 2 b of the first rotating cylinder 2. Enter inside. The elastic transmission arm portion 7 a of the barrier spring 7 is retracted from the concave portion 1 c 1 of the first rectilinear cylinder 1 and enters the third groove portion 2 c of the first rotating cylinder 2.

  In the opening / closing operation of the barrier blades 4 to 10 described above, the barrier springs 6 and 7 only rotate according to the rotation of the first rotating cylinder 2 and are hardly charged. That is, the driving load on the first rotating cylinder 2 when the barrier blades 4 to 10 are opened and closed can be reduced as compared with the case where the springs are charged when the barrier blades are opened and closed as in the prior art described above. .

  Hereinafter, the operation of the barrier unit when the barrier blades 4 to 10 cannot operate according to the rotation of the first rotating cylinder 2 will be described. In addition, since the operation | movement regarding the barrier blades 4 and 9 and the operation | movement regarding the barrier blades 5 and 10 are the same, only the operation | movement regarding the barrier blades 4 and 9 is described in the following description.

(3) When the barrier blades in the fully closed state are forcibly opened The barrier blades 4 and 9 are forcibly rotated in the opening direction when the barrier unit is in the fully closed state shown in FIG. Will be described.

  When the barrier blade 4 in the fully closed state is forcibly rotated in the opening direction, the barrier spring 6 rotates together with the barrier blade 4. Here, since the first rotating cylinder 2 does not rotate and remains stopped at the position shown in FIG. 4, the elastic transmission arm 6 b that abuts against the protrusion 2 g of the first rotating cylinder 2 becomes a fixed arm, and the barrier blade The elastic transmission arm portion 6a of the barrier spring 6 that contacts the four groove portions 4b2 serves as a movable arm.

  That is, as shown in FIG. 11, by the rotation of the barrier blade 4 in the opening direction, the elastic transmission arm portion 6b abuts against the side surface 2g2 of the protrusion 2g and is held in the abutted state. Further, the elastic transmission arm portion 6 a is pushed into the barrier blade 4 (groove portion 4 b 2) and displaced inward in the radial direction of the first rotating cylinder 2. As a result, the barrier spring 6 is elastically deformed and charged.

  Here, depending on the amount of rotation of the barrier blade 4, the elastic transmission arm portion 6 a enters the recess 1 b 1 of the first rectilinear cylinder 1 as shown in FIG. 11.

  When the forcible opening operation of the barrier blade 4 is stopped while the barrier spring 6 is charged, the barrier blade 4 rotates in the closing direction by the charging force (restoring force) of the barrier spring 6 and returns to the fully closed state. . When not only the barrier blade 4 but also the barrier blade 9 rotates in the opening direction, the barrier blade 9 together with the barrier blade 4 is brought into contact with the protrusion 4c of the barrier blade 4 and the notch 9b of the barrier blade 9. It will rotate in the closing direction.

(4) When the barrier blade closing operation is obstructed In the stage of rotating the first rotating cylinder 2 in the arrow B direction from the fully opened state shown in FIG. The case where the rotation in the closing direction is prevented will be described.

  When the first rotating cylinder 2 rotates in the arrow B direction, the side surface 2g2 of the protrusion 2g of the first rotating cylinder 2 comes into contact with the elastic transmission arm 6b of the barrier spring 6 as shown in FIG. Here, when the barrier blade 4 is prevented from rotating in the closing direction, the elastic transmission arm 6a of the barrier spring 6 that contacts the groove 4b2 of the barrier blade 4 serves as a fixed arm, and the elastic transmission arm that contacts the protrusion 2g. The part 6b becomes a movable arm.

  That is, in the state shown in FIG. 10, since the rotation of the barrier blade 4 in the closing direction is prevented, the elastic transmission arm portion 6a remains in contact with the barrier blade 4 (groove portion 4b2). On the other hand, since the first rotating cylinder 2 rotates to the position shown in FIG. 4, the elastic transmission arm 6b is pushed into the protrusion 2g of the first rotating cylinder 2 and is displaced as shown in FIG. As a result, the barrier spring 6 is elastically deformed and charged.

  When the rotation prevention of the barrier blade 4 is released while the barrier spring 6 is charged, the barrier blade 4 receives the charging force (restoring force) of the barrier spring 6 and rotates in the closing direction. Further, the barrier blade 9 is also rotated in the closing direction by the contact between the convex portion 4c of the barrier blade 4 and the notched portion 9b of the barrier blade 9.

  At this time, the elastic transmission arm 6a enters the first groove 2b and enters the state shown in FIG. Further, the barrier blades 4 and 9 are fully closed as shown in FIG.

(5) When the opening operation of the barrier blade is obstructed In the stage of rotating the first rotating cylinder 2 in the arrow A direction from the fully closed state shown in FIG. A case where rotation in the opening direction of 5 is prevented will be described.

  When the first rotating cylinder 2 rotates in the direction of arrow A, the side surface 2g1 of the protrusion 2g contacts the elastic transmission arm 6a of the barrier spring 6. When rotation in the opening direction of the barrier blade 4 is prevented in this state, the elastic transmission arm portion 6b that contacts the groove 4b1 of the barrier blade 4 becomes a fixed arm, and the elastic transmission arm portion 6a that contacts the protrusion 2g is movable. Become an arm.

  That is, since the barrier blade 4 is prevented from rotating in the opening direction, the elastic transmission arm portion 6b remains in contact with the groove portion 4b1. On the other hand, since the first rotating cylinder 2 rotates in the direction of arrow A and moves to the fully open position shown in FIG. 8, the elastic transmission arm portion 6a is pushed into the protrusion 2g of the first rotating cylinder 2, As shown in FIG. 13, the first rotary cylinder 2 is displaced radially inward. The elastic transmission arm portion 6a is in contact with the inner peripheral surface 2f of the first rotary cylinder 2.

  As a result, the barrier spring 6 is deformed and charged.

  When the rotation prevention of the barrier blade 4 is released in a state where the barrier spring 6 is charged, the barrier blade 4 receives the charging force (restoring force) of the barrier spring 6 and rotates in the opening direction. Further, the barrier blades 9 are also rotated in the opening direction by the contact of the convex portions 9c of the barrier blades 4 and 9.

  At this time, the elastic transmission arm 6b comes into contact with the protrusion 2g, and the barrier spring 6 is in the state shown in FIG. Further, the barrier blades 4 and 9 are fully opened as shown in FIG.

  When the above-described barrier spring 6 is returned from the charged state, the elastic transmission arm portions 6a and 6b collide with the projecting portion 2g, so that the barrier blade 4 is vibrated. As a result, even if dust or the like, which becomes a factor that hinders the opening / closing operation, adheres to the barrier blade 4, the dust or the like can be removed by the vibration.

  As described above, according to the present embodiment, since the barrier springs 6 and 7 are directly driven by the first rotating cylinder 2 to open and close the barrier blades 4 and 5, the barrier as in the prior art described above. It is possible to reduce the dedicated parts required for driving the blades. Thereby, the cost increase by the increase in a number of parts can be suppressed. In addition, since the space for arranging the dedicated parts can be reduced, the barrier unit and the lens barrel can be reduced in size.

  On the other hand, when the barrier blades 4 to 10 are opened and closed, the elastic transmission arm portions 6a and 7a are pushed and displaced by the protrusions 2g and 2h of the first rotating cylinder 2 as described above. The blades 4 and 5 may be separated from the grooves 4b2 and 5b2. The elastic transmission arm portions 6a and 7a removed from the grooves 4b2 and 5b2 are displaceable in the optical axis direction. For example, the external force applied to the lens barrel 101 and the rotation axis direction of the barrier springs 6 and 7 are provided. May cause the elastic transmission arm portions 6a and 7a to be displaced in the optical axis direction.

  When the elastic transmission arm portions 6a and 7a are greatly displaced in the optical axis direction (displaced larger than a predetermined amount below), it becomes difficult to drive the barrier blades 4 to 10 smoothly.

  Here, it is also conceivable to set the size of the grooves 4b2 and 5b2 to such an extent that the elastic transmission arms 6a and 7a are not displaced from the grooves 4b2 and 5b2 even if they are pushed and displaced by the protrusions 2g and 2h. However, in this case, the barrier blades 4 and 5 (particularly, the groove portions 4b2 and 5b2) are increased in size, and the lens barrel 101 is increased in the radial direction.

  Therefore, in this embodiment, the elastic transmission arm portions 6a and 7a pushed by the protrusions 2g and 2h of the first rotating cylinder 2 are caused to enter the recesses 1b1 and 1c1 formed in the first rectilinear cylinder 1. By doing so, the displacement of the elastic transmission arm portions 6a and 7a in the optical axis direction can be limited to a predetermined amount. That is, the elastic transmission arm portions 6a and 7a are prevented from being displaced more than the predetermined amount in the optical axis direction by the two optical axis orthogonal surfaces of the recesses 1b1 and 1c1. In such a configuration, it is not necessary to enlarge the grooves 4b2 and 5b2 as described above, and the increase in size of the barrier blades 4 and 5 and the lens barrel 101 can be suppressed.

  In addition, as an area for forming the protrusions 1b and 1c having the recesses 1b1 and 1c1, an existing member, that is, an end face of the first rectilinear barrel 1 to which the first lens group 3 is fixed is used in the lens barrel 101. The configuration in the lens barrel can be simplified.

  In this embodiment, the recesses 1b1 and 1c1 are formed in the first rectilinear cylinder 1. However, the barrier cover 8 and the barrier plate 11 are portions (recesses) that limit the displacement of the elastic transmission arm portions 6a and 7a in the optical axis direction. It is also possible to form a portion corresponding to 1b1 and 1c1.

  In the present embodiment, the barrier blades 4 to 10 are closed when the first rotating cylinder 2 (projections 2g and 2h) and the barrier springs 6 and 7 are in the state (positional relationship) shown in FIG. However, when the first rotating cylinder 2 and the barrier springs 6 and 7 are in the positional relationship shown in FIG. 4, the barrier blades may be in an open state. That is, the above configuration can be obtained by appropriately changing the shape of the barrier blade. Also in this configuration, by forming a concave portion (corresponding to the concave portions 1b1 and 1c1) into which the elastic transmission arm portion pushed by the first rotating cylinder enters the first rectilinear cylinder 1, the light of the elastic transmission arm portion is formed. The displacement in the axial direction can be limited to a predetermined amount.

It is a disassembled perspective view which shows the structure of the barrier unit in Example 1 of this invention. It is an external appearance perspective view of the barrier blade | blade incorporating the barrier spring. It is a perspective view which shows the relationship between the rotating cylinder and barrier spring in Example 1. FIG. It is a front view of the barrier unit in the fully closed state in the first embodiment. It is a front view of the barrier unit in the half-open state in the first embodiment. It is a front view of the barrier unit in the state just before full opening in Example 1. It is the elements on larger scale of the barrier unit in the state just before full opening. It is a front view of the barrier unit in a fully opened state in Example 1. It is the elements on larger scale of the barrier unit in a full open state. It is a front view of the barrier unit in the closing operation start state of the barrier blade. It is a front view of the barrier unit in a forced open state. It is a front view of the barrier unit in a state where the closing operation of the barrier blades is prevented. It is a front view of the barrier unit in a state where the opening operation of the barrier blades is prevented. 3 is a cross-sectional view of a lens barrel in Embodiment 1. FIG. 1 is an external perspective view of a camera in Embodiment 1. FIG.

Explanation of symbols

1: first straight cylinder 1b, 1c: convex part 1b1, 1c1: concave part 2: first rotary cylinder 2b: first groove part 2d: second groove part 2c: third groove part 2e: fourth groove part 2g, 2h : Projection 2f: Inner peripheral surface 3: First lens groups 4, 5, 9, 10: Barrier blades 4b1, 4b2: Grooves 5b1, 5b2: Grooves 6, 7: Barrier springs 6a, 6b, 7a, 7b: Elastic transmission Arm 8: Barrier cover

Claims (7)

A barrier member that opens and closes the front surface of the photographic optical system;
A fixing member;
A rotating member rotatable around the optical axis with respect to the fixed member;
A spring member having an arm portion and attached to the barrier member;
The rotating member drives the barrier member by pushing the arm part by a rotating operation,
The lens device according to claim 1, wherein the fixing member includes a limiting unit that limits a displacement in the optical axis direction of the arm portion pressed by the rotating member. The limiting portion has two optical axis orthogonal surfaces facing each other,
The lens apparatus according to claim 1, wherein the arm portion pushed by the rotating member enters between the two optical axis orthogonal planes.   The lens device according to claim 1, wherein the arm portion is formed in a shape having a curvature.   4. The lens device according to claim 1, wherein when the barrier member is in a closed state or an open state, the rotating member holds the arm portion pressed. 5.   5. The lens device according to claim 1, wherein the spring member allows an operation of only one of the rotating member and the barrier member by elastic deformation. A lens device according to any one of claims 1 to 5;
A camera comprising: an exposure device that exposes a silver salt film to an object image formed by a photographing optical system in the lens device. A lens device according to any one of claims 1 to 5;
An image pickup device that photoelectrically converts an object image formed by a photographing optical system in the lens device.

Images