JP2011033886A - Lens device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent change of a lens position when completing adjustment of eccentricity, even if a pressing ring is tightened after the pressing ring is loosened and the adjustment of the eccentricity of the lens is completed. <P>SOLUTION: In the lens device, a fixed lens frame 3 is fixed by being pressed against a lens barrel 10 (front frame 10) in an optical axis 0 direction by the pressing ring 4 screwed and fitted in an inner periphery of the lens barrel 10. The lens device includes an annular corrugated leaf spring 5 arranged between the pressing ring 4 and the fixed lens frame 3 and energizing the fixed lens frame 3 to an abutting surface 10A of the lens barrel 10 in the optical axis 0 direction. A projection 5A is formed on an outer periphery of the corrugated leaf spring 5, and a recessed part 10C corresponding to the projection 5a of the corrugated leaf spring 5 is formed on the inner periphery of the lens barrel 10. By fitting the projection 5A of the corrugated leaf spring 5 in the recessed part 10C of the lens barrel 10, turning of the corrugated leaf spring 5 is regulated. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a lens apparatus, and more particularly to a lens eccentricity adjusting structure.

  2. Description of the Related Art Conventionally, a lens device used for a portable ENG (Electronic News Gathering) camera used for television coverage or the like is known (Patent Document 1).

  In addition, the lens holding frame of the lens located closest to the subject is rotatably fitted to the lens barrel, and the lens is adjusted by rotating the lens holding frame with respect to the lens barrel. A structure is known in which the lens holding frame is pressed and fixed to the lens barrel by screwing a presser ring inserted from the subject side of the lens holding frame into the lens barrel in a state where the eccentricity is adjusted ( Patent Document 2).

JP 2003-29123 A JP 2007-219023 A

  However, after adjusting the lens eccentricity by loosening the presser ring and turning the lens holding frame, if the presser ring is tightened, the lens holding frame will rotate together with the presser ring, and the lens position has been adjusted. There is a problem of changing from the best position of time.

  The present invention has been made in view of such circumstances, and provides a lens device capable of preventing the lens position from changing when the eccentric adjustment is completed even if the presser ring is tightened after completion of the eccentric adjustment of the lens. With the goal.

  In order to achieve the above-mentioned object, according to the present invention, a lens holding frame holding a lens is pressed against the lens barrel in the optical axis direction of the lens by a presser ring screwed to the inner periphery of the lens barrel. A fixed lens device, which is disposed between the presser ring and the lens holding frame, and has an annular shape that urges the lens holding frame to a contact portion of the lens barrel in the optical axis direction of the lens. A biasing member, a protrusion is formed on an outer periphery of the biasing member, a recess corresponding to the protrusion of the biasing member is formed on an inner periphery of the lens barrel, and the protrusion of the biasing member and the protrusion Provided is a lens device that restricts the rotation of the urging member by fitting the concave portion of the lens barrel.

  According to the present invention, the lens holding frame is prevented from falling by the urging of the urging member, and even if the presser ring is tightened after the presser ring is loosened and the eccentric adjustment of the lens is completed, the protrusion of the urging member and the lens mirror Since the concave portion of the body is fitted, the lens holding frame does not rotate together with the presser ring, and the lens position when the eccentricity adjustment is completed can be maintained.

  In one aspect of the present invention, a member that is disposed closest to the optical axis side of the lens among members constituting the lens barrel and the lens holding frame are fitted. Thereby, it is possible to prevent the lens position shift due to the stacking of components.

  For example, the lens is the foremost lens disposed at the forefront closest to the subject, and the urging member and the presser ring are inserted into the lens barrel from the front rather than the lens holding frame. It is attached to the lens barrel. Further, for example, the lens is a rearmost lens disposed at the rearmost position farthest from the subject, and the urging member and the presser ring are inserted into the lens barrel from behind the lens holding frame. And attached to the lens barrel.

  According to the present invention, even if the presser ring is tightened after completion of the eccentricity adjustment of the lens, the lens position at the completion of the eccentricity adjustment can be prevented from changing.

The sectional view which looked at the lens apparatus concerning the present invention from the side The perspective view which shows the external appearance of the front part of the lens apparatus shown in FIG. Sectional view along line F3-F3 in FIG. The perspective view which shows the front external appearance of the lens apparatus which does not mount | wear with a lens hood The perspective view which shows the front external appearance of the lens apparatus with which the lens hood and the adjustment hole cover are not attached Sectional drawing along F6-F6 line of FIG. Exploded perspective view showing presser ring, corrugated spring and fixed lens frame Explanatory drawing which shows a mode that the gear of the lens holding frame was seen from the adjustment hole Sectional drawing which shows an example of the lens apparatus for demonstrating the eccentricity adjustment structure of a rearmost lens The top view which shows the lens frame of FIG.

  Hereinafter, embodiments of a lens apparatus according to the present invention will be described with reference to the accompanying drawings.

[Entire configuration of lens device]
FIG. 1 is a sectional view of a rear focus type variable focal length lens device applied to the present invention applied to, for example, a consumer video camera, a television broadcast ENG camera, a surveillance camera, etc., as viewed from the side. Yes, with respect to the upper half from the optical axis O.

  In FIG. 1, a front frame 10, a front fixed ring 12, a first main body ring 14, a second main body ring 16, a rear fixed ring 18, a mount mounting frame 20 and a mount ring 22 are integrally connected to each other, and are substantially cylindrical. A lens barrel is configured. The lens barrel body is attached to the interchangeable lens camera body by the mount ring 22.

  The first main body ring 14 is an innermost component of the lens barrel main body. The front fixed ring 12 is fixed to the front side of the outer periphery of the first main body ring 14 with a screw, and the front of the front fixed ring 12 is in front. The frame 10 is fixed with screws. Further, the second main body ring 16 is fixed to the rear side of the outer periphery of the first main body ring 14 with a screw, the rear fixed ring 18 is located behind the second main body ring 16, the mount mounting frame 20 is located behind the rear fixed ring 18, Mount rings 22 are fixed to the rear of the mount mounting frame 20 with screws.

  On the inner periphery of the front frame 10, the fixed lens frame 3 holding the frontmost (most subject side) fixed lens 30 is attached. Moreover, the presser ring 4 is screwed to the inner periphery of the front frame 10 so as to be rotatable. The presser ring 4 fixes the fixed lens frame 3 to the front frame 10 by pressing the fixed lens frame 3 against the front frame 10 in the optical axis 0 direction via an annular corrugated spring 5. A gear 3 </ b> A for rotating the fixed lens frame 3 is formed on the outer peripheral side surface of the fixed lens frame 3. Further, an adjustment hole 10D is formed in the front frame 10, and the adjustment hole cover 6 is fitted into the adjustment hole 10D. A lens hood 24 is detachably attached to the front frame 10. The structure around the fixed lens 30 will be described in detail later.

  The optical system in the lens apparatus 1 includes, in order from the object side, a fixed lens (first group lens) 30, a zoom (variation) lens (second group lens) 32, a front master lens (third group lens) 34, a focus. It consists of five groups, a lens (fourth group lens) 36 and a rear master lens (fifth group lens) 38. In addition, an iris diaphragm 40 is provided immediately before the front master lens 34.

  The lens frame 42 to which the zoom lens 32 is attached is fixed to the moving frame 46 by a presser ring 44. A cam cylinder 48 is rotatably held on the inner peripheral portion of the first main body ring 14, and the moving frame 46 is held on the inner peripheral portion of the cam cylinder 48 via a cam pin 46A. That is, a rectilinear groove 14A in the direction of the optical axis O is formed on the inner peripheral surface of the first main body ring 14, and a cam groove (cam-shaped hole) 48A is formed in the cam cylinder 48. The cam pin 46 </ b> A fixed to is inserted into the cam groove 48 </ b> A of the cam cylinder 48 and engaged with the rectilinear groove 14 </ b> A of the first main body ring 14. As a result, the moving frame 46 is held so as to be able to advance straight in the direction of the optical axis O in a state where the rotation is restricted, and at the position where the cam pin 46A is engaged with the cam groove 48A. Therefore, when the cam cylinder 48 rotates, the intersection position of the cam groove 48A of the cam cylinder 48 and the rectilinear groove 14A of the first main body ring 14 changes to a position corresponding to the cam shape, and the cam pin 46A to the intersection position changes. Due to the movement, the moving frame 46 moves back and forth in the direction of the optical axis O.

  On the other hand, a zoom ring 50 is rotatably disposed on the outer peripheral portion of the second main body ring 16, and a rod-like connecting shaft 52 is attached radially inward of the inner peripheral surface of the zoom ring 50. . The connecting shaft 52 is connected to the cam cylinder 48 through a long hole (not shown) in the circumferential direction formed in the first main body ring 14. As a result, when the zoom ring 50 is rotated, the cam cylinder 48 is rotated in conjunction therewith. When the cam cylinder 48 rotates, the moving frame 46 moves forward and backward as described above, and the zoom lens 32 moves in the direction of the optical axis O in conjunction with the moving frame 46. Accordingly, the zoom magnification is changed by rotating the zoom ring 50.

  The iris diaphragm 40 is mainly configured by a plastic base plate (aperture frame) 54, a chrysanthemum seat (cam plate) 56, and a plurality of diaphragm blades 58 disposed between the diaphragm frame 54 and the cam plate 56. ing. An iris ring 60 is rotatably disposed between the rear fixed ring 18 and the mount mounting frame 20, and a connecting shaft 56 </ b> A extending from the cam plate 56 is connected to the iris ring 60. Thus, the cam plate 56 is rotated by the rotation of the iris ring 60, and the aperture blade 58 is opened and closed.

  The focus lens 36 changes the focal position of the optical system. The rear lens fixed ring that holds the front master lens 34 and the like, and the lens frame of the rear master lens 38 disposed at the rear end of the rear lens fixed ring. 64 is supported so as to be movable in the direction of the optical axis O by a guide shaft and a detent (not shown) held between the two. In addition, a pair of voice coil motors (VCM) 66 is disposed on the rear lens fixed ring with a guide shaft interposed therebetween, and the focus lens 36 is electrically driven by the power of the VCM 66. .

  A first focus ring 70 and a second focus ring 72 are rotatably arranged on the outer peripheral portion of the front fixed ring 12. The rotation range of the first focus ring 70 is not restricted, and the first focus ring 70 can be rotated endlessly and is slidable in the optical axis direction. Further, the second focus ring 72 is restricted by a stopper shaft 74 so as to be rotatable within a range of about 120 degrees.

  Sawtooth-shaped clutch portions 70A and 72A are formed on the end faces where the first focus ring 70 and the second focus ring 72 face each other. In the state shown in FIG. 1, the clutch portions 70A and 72A are connected (engaged). Then, the first focus ring 70 and the second focus ring 72 rotate integrally. Therefore, in this state, when the first focus ring 70 is manually rotated, it can be rotated only within a range of about 120 degrees.

  On the other hand, when the first focus ring 70 is slid forward so as to get over the click elastic member 76, the clutch portions 70A and 72A are disconnected. Thereby, the first focus ring 70 can be rotated endlessly.

  A drive unit (not shown) that also serves as a grip unit is attached to the side surface of the lens device 1 having the above configuration via screw holes 80 and 82.

  The drive unit includes a drive unit for driving the zoom ring 50 and the iris ring 60, and a control board is disposed inside, and the zoom lens 32 and the like are driven and controlled electrically by a seesaw type zoom switch, and the focus is adjusted. The lens 36 and the iris diaphragm 40 are controlled.

<Various detection means>
A linear potentiometer is disposed on the outer peripheral surface of the first main body ring 14 along the optical axis direction. In the linear potentiometer (zoom linear POT), the zoom lens 32 is moved in the optical axis direction by the rotation of the cam cylinder 48. When it moves, a position signal (signal indicating an absolute position) corresponding to the moving position is output to the drive unit via the lead wire.

  A magnetic ring 84 with N and S poles magnetized is bonded to the rear end surface of the cam cylinder 48, and a magnetic sensor (MR sensor) is opposed to the magnetic ring 84 on the first body ring 14. Is arranged. When the magnetic ring 84 rotates together with the cam cylinder 48, the MR sensor outputs a pulse signal (a signal indicating a relative position) having the number of pulses corresponding to the rotation amount to the drive unit via the lead wire.

  The output of the zoom linear POT is used when the power is turned on, and thereafter, the output of the MR sensor for detecting the zoom position is used.

  An MR sensor for detecting the focus lens position is disposed on the rear lens fixed ring facing the guide shaft of the focus lens 36, and this MR sensor is a pulse signal having the number of pulses corresponding to the amount of movement of the focus lens 36. (A signal indicating a relative position) is output to the drive unit via the lead wire. In addition, a home position sensor (photo interrupter) for detecting the reference position of the focus lens 36 is disposed in the rear lens fixed ring, and the drive unit detects the reference position of the focus lens 36 detected by the home position sensor. The absolute position of the focus lens 36 is detected by counting the output signal of the MR sensor with reference to.

  Gears 70B and 72B are formed around the first focus ring 70 and the second focus ring 72, respectively, and these gears 70B and 72B are respectively relative position detection type sensors (incremental) provided on the drive unit side. Encoder), and a detection shaft gear of an absolute position detection type sensor (absolute encoder).

  Accordingly, the drive unit can detect the relative rotation amount of the first focus ring 70 and can detect the absolute rotation position of the second focus ring 72.

  In addition, a photo interrupter 86 is provided at the front end of the front fixed ring 12, while a light shielding plate 70 </ b> C is provided at the front end of the first focus ring 70. The photo interrupter 86 outputs a detection signal indicating the presence or absence of the light shielding plate 70C to the drive unit. Accordingly, the driving unit can detect whether or not the first focus ring 70 is connected to the second focus ring 72 based on the detection signal from the photo interrupter 86.

[Lens control]
A slide-type macro ON / OFF switch, an AF / MF switching switch, and a non-locking AF push switch are disposed on the side surface of the mount mounting frame 20, and output signals associated with the operation of these switches. Is added to the drive unit via a lead wire.

  Here, the macro ON / OFF switch is a switch for turning on / off the macro photographing mode. The AF / MF selector switch manually rotates the first focus ring and an auto focus (AF) mode in which the focus lens 36 is automatically moved to adjust the focus so that the contrast of the subject image is maximized. This is a switch for switching the manual focus (MF) mode in which the focus lens 36 is moved to adjust the focus. The AF push switch is a switch that switches to the AF mode only during a period when the key top is pressed (pushed) when the AF / MF switch is switched to the MF mode.

<Focus control>
When the AF mode is switched to the AF mode by the AF / MF switch, the drive unit automatically moves the focus lens 36 to the in-focus position regardless of the operation of the first focus ring 70 and the second focus ring 72. AF control is performed.

  On the other hand, when the AF / MF switch is switched to the MF mode, the full MF mode (with end) and the AF / MF mode (endless) are switched according to the slide position of the first focus ring 70. It is like that.

  That is, the drive unit can detect the slide position of the first focus ring 70 (whether the first focus ring 70 is connected to the second focus ring 72) based on the detection signal from the photo interrupter 86 described above. When the first focus ring 70 is connected to the second focus ring 72, the mode is switched to the full MF mode. When the first focus ring 70 is not connected to the second focus ring 72, the AF / MF mode is set. Switch.

  In the full MF mode in which the first focus ring 70 is connected to the second focus ring 72, the drive unit detects the absolute position signal (closest distance) from the absolute position detection type sensor connected to the gear 72B of the second focus ring 72. Signal indicating the absolute position of the zoom position obtained from the output of the zoom linear POT when the power is turned on and the output of the MR sensor for detecting the zoom position thereafter. The focus lens 36 is driven and controlled based on the signal indicating the magnification. That is, the position to which the focus lens 36 should move corresponding to the shooting distance is set in advance according to the current zoom position (zoom magnification) of the zoom lens 32, and the drive unit manually operates the first focus ring 70. When the second focus ring 72 is rotated in conjunction with this, the focus lens 36 is moved to a corresponding position based on a signal indicating the rotation position (signal for instructing the shooting distance) and the current zoom magnification.

  When the mode is switched to the full MF mode in this way, the focus lens 36 can be moved to a position corresponding to a desired shooting distance by manually operating the first focus ring 70. Since the first focus ring 70 is connected to the second focus ring 72 with an end whose rotation range is restricted by the stopper shaft 74, the rotation range is restricted similarly to the second focus ring 72. Thus, it can be rotated within a rotation range corresponding to the infinity end from the closest end.

  In the full MF mode, the rotation range of the first focus ring 70 is limited via the second focus ring 72, and the operator can adjust the focus lens according to the operation feeling when the first focus ring 70 reaches the end. It can be recognized that 36 has reached the near end or the infinity end. Such a focus operation using only the first focus ring 70 is a method familiar to professional photographers and the like.

  On the other hand, in the AF / MF mode in which the first focus ring 70 is not connected to the second focus ring 72, the MF mode in which the focus lens 36 is moved by rotating the first focus ring 70, and the AF push switch described above. Focus control can be performed by properly using the AF mode by pressing the button.

  That is, when the first focus ring 70 is operated in the AF / MF mode and a relative position signal is input from the relative position detection type sensor connected to the gear 70B of the first focus ring 70, the driving unit receives the relative position. The focus lens 36 is driven and controlled based on the signal, and the focus lens 36 is moved by an amount corresponding to the amount of rotation of the first focus ring 70.

  In the AF / MF mode, since the first focus ring 70 is not connected to the second focus ring 72, the rotation range thereof is not restricted, and the end lens can be rotated endlessly. When moving to the position of the end or the closest end, a movement command exceeding the end is not output.

  In addition, when the AF push switch is pressed during AF / MF mode, the AF lens is temporarily switched to AF mode. After that, when the AF push switch is released to switch to MF mode, the focus lens 36 automatically focused by the AF mode is switched. By taking over the position, the focus lens 36 can be displaced by the amount of operation of the first focus ring 70, which improves usability.

<Zoom control>
When a seesaw-type zoom switch provided in the drive unit is operated, a rotational driving force is transmitted from an electric motor in the drive unit to a gear 50A formed around the zoom ring 50, thereby rotating the zoom ring 50. It can be made to. Further, the zoom ring 50 can be rotated by manually operating the zoom ring 50 (a zoom lever (not shown) implanted in the zoom ring 50).

  When the zoom ring 50 rotates, the cam cylinder 48 connected via the connecting shaft 52 rotates, and when the cam cylinder 48 rotates, the rectilinear groove 14A formed in the first main body ring 14 and the cam cylinder. The moving frame 46 moves back and forth in the direction of the optical axis O via the cam pin 46A engaged with the cam groove 48A. When the zoom ring 50 is thus rotated, the zoom lens 32 can be moved in the direction of the optical axis O, and the zoom magnification can be changed.

  When the zoom magnification changes due to the movement of the zoom lens 32 as described above, the focal plane moves. However, the drive unit also uses the focus lens 36 as a correction optical system that corrects the movement of the focal plane accompanying the change in the zoom magnification. The position of the focus lens 36 is controlled so that the focal plane does not move regardless of the zoom magnification.

  That is, the drive unit obtains the current zoom position of the zoom lens 32 before the zoom operation from the output of the zoom linear POT when the power is turned on and the output of the MR sensor for detecting the zoom position thereafter, and the current focus lens. The position of 36 is acquired from the MR sensor for detecting the focus lens position, and the acquired zoom position is obtained from a correction curve indicating the relationship between the zoom position where the focal plane prepared in advance for each shooting distance is not moved and the focus lens position. When a corresponding correction curve is selected based on the focus lens position and then the amount of movement of the zoom lens 32 is detected based on the output signal of the MR sensor for detecting the zoom lens position, the detected zoom position is detected. The focus lens position (focus lens position that does not move the focal plane) corresponding to Read from the curve, and moves the focus lens 36 to the read focus lens position.

  As a result, the focus plane is adjusted by the focus control so that the focal plane is positioned on the image pickup device of the camera body on which the lens apparatus 1 is mounted. Can not be shifted).

This prevents the focal plane from moving even when the zoom magnification is changed. Therefore, once focus adjustment is performed so that the focal plane is positioned on the image pickup device of the camera body on which the lens apparatus 1 is mounted by focus control, it is possible to prevent the focus from being shifted even after zooming.
[Embodiment]
Hereinafter, the eccentricity adjustment structure of the fixed lens 30 will be described in detail.

  FIG. 2 is a perspective view showing a front appearance of the lens apparatus 1 shown in FIG. 3 is a cross-sectional view taken along line F3-F3 in FIG. FIG. 4 is a perspective view showing the front appearance of the lens apparatus 1 when the lens hood 24 is not attached.

  As shown in FIG. 3, the fixed lens frame 3 holding the fixed lens 30 is in contact with the contact surface 10 </ b> A (contact portion) of the front frame 10 in the optical axis 0 direction of the fixed lens 30. Further, a female screw 10B is formed on the inner peripheral side surface of the front end of the front frame 10, and the male screw 4A of the presser ring 4 is screwed to the female screw 10B. That is, the fixed lens frame 3 is pressed against the contact surface 10A of the front frame 10 in the direction of the optical axis 0 by the presser ring 4 screwed to the inner periphery of the front frame 10 and fixed. Further, in order to prevent a positional shift (optical axis shift) due to the stacking of the members constituting the lens barrel, the fixed lens frame 3 is a member arranged closest to the optical axis 0 among the members constituting the lens barrel. (That is, the innermost first main body ring 14 of the lens barrel) is fitted. In this example, the outer peripheral side surface of the rear end of the fixed lens frame 3 is fitted to the inner peripheral side surface of the first main body ring 14.

  A corrugated spring 5 is interposed between the presser ring 4 and the fixed lens frame 3 as an annular urging member. The corrugated spring 5 biases the fixed lens frame 3 toward the contact surface 10A of the front frame 10 in the optical axis 0 direction.

  In a state where the presser ring 4 is loosened (that is, a state where the pressing of the fixed lens frame 3 against the contact surface 10A of the front frame 10 is loosened), the fixed lens frame 3 is moved around the optical axis 0 by an operation from the side of the front frame 10. In order to be able to rotate, a gear 3A is formed on the outer peripheral side surface of the fixed lens frame 3, and an opening 10D (hereinafter referred to as the gear 3A of the fixed lens frame 3) is exposed in the front frame 10 surrounding the outer periphery of the fixed lens frame 3. (Referred to as “adjustment holes”). In FIG. 3, the detachable adjustment hole cover 6 is fitted in the adjustment hole 10D, and the adjustment hole 10D is closed. The adjustment hole 10 </ b> D is covered with a lens hood 24 attached to the front frame 10.

  The materials of the fixed lens frame 3 and the front frame 10 and the adjustment hole cover 6 and the lens hood 24 are not particularly limited. In this example, the fixed lens frame 3 and the front frame 10 are made of metal, and the adjustment hole cover. 6 and the lens hood 24 are made of synthetic resin.

  The gear 3 </ b> A is disposed in the vicinity of the center of gravity of the fixed lens 30 in the optical axis 0 direction. It is preferable to arrange the gear 3 </ b> A from the position of the center of gravity of the fixed lens 30 to a position corresponding to ¼ in terms of the weight of the fixed lens 30. In this example, the contact surface 10A of the front frame 10 is disposed at the center of gravity of the fixed lens 30 in the optical axis 0 direction, and the contact surface 10A is closer to the contact surface 10A than the front end of the outer periphery of the fixed lens 30. A gear 3 </ b> A is arranged at a close position.

  FIG. 5 is a perspective view showing a front appearance of the lens apparatus 1 to which the lens hood 24 and the adjustment hole cover 6 are not attached. 6 is a cross-sectional view taken along line F6-F6 of FIG.

  As shown in FIG. 5, a notch 4B is formed at the front end of the outer periphery of the presser ring 4, and a presser ring rotating jig (not shown) is fitted to the notch 4B to fit the presser ring rotating jig. By rotating, the presser ring 4 can be tightened or loosened from the front of the front frame 10.

  Further, a notch 10E is also formed at the outer peripheral front end 3B of the fixed lens frame 3 of this example, and it is possible to rotate the fixed lens frame 3 from the front of the front frame 10, but this notch 10E can be omitted. Further, the fixed lens frame 3 of the present example holds the fixed lens 30 by heat caulking.

  FIG. 7 is an exploded perspective view showing the presser ring 4, the wave plate spring 5, and the fixed lens frame 3.

  In FIG. 7, a protrusion 5 </ b> A is formed on the outer periphery of the corrugated spring 5. As shown in FIG. 5, a recess 10 </ b> C corresponding to the protrusion 5 </ b> A of the corrugated spring 5 is formed on the inner peripheral side surface of the front frame 10. By fitting the projection 5A of the wave plate spring 5 and the recess 10C of the front frame 10, the rotation of the wave plate spring 5 around the optical axis 0 is restricted.

  In this embodiment, in the state shown in FIG. 5 (the lens hood 24 and the adjustment hole cover 6 are not attached), the presser ring 4 is loosened and the eccentric adjustment of the fixed lens 30 is performed. FIG. 8 shows a state where the gear 3A is viewed from the adjustment hole 10D. An eccentricity adjustment jig (not shown) is inserted into the adjustment hole 10D, the tip of the eccentricity adjustment jig is fitted to the gear 3A of the fixed lens frame 3, and the fixed lens frame 3 is rotated about the optical axis 0. Let As a result, the fixed lens 30 rotates about the optical axis 0. In the lens device 1 of the present embodiment, the gear 3A is formed on the outer peripheral side surface of the fixed lens frame 3, and the adjustment hole 10D that exposes the gear 3A is formed in the front frame 10. While the pressing of the fixed lens frame 3 is loosened, the fixed lens 30 is rotated by the gear 3A through the adjustment hole 10D while observing the measurement value or image of the measuring machine not shown behind the lens barrel. Thus, the eccentric adjustment of the fixed lens 30 can be easily performed.

  After the eccentric adjustment of the fixed lens 30 is completed, a convex portion of a presser ring rotating jig (not shown) is fitted into the notch 4B of the presser ring 4, and the presser ring 4 is rotated about the optical axis 0 and tightened. Then, the fixed lens frame 3 is pressed against the contact surface 10A of the front frame 10 and fixed. Even if the presser ring 4 is rotated in this way, the concave portion 10C of the front frame 10 and the projection 5A of the corrugated spring 5 are fitted to restrict the pivoting of the corrugated spring 5, so The fixed lens frame 3 does not rotate. That is, it is possible to prevent the position of the fixed lens 30 from changing from the best position when the eccentricity adjustment is completed.

  As described above, the forefront lens (fixed lens 30) disposed at the forefront closest to the subject is the object of eccentricity adjustment, and the biasing member (wave plate spring 5) and the presser ring 4 are connected to the lens holding frame (fixed lens frame 3). The case where the lens barrel (front frame 10) is inserted into the lens barrel (front frame 10) and mounted from the front is described as an example, but the present invention is not particularly limited to such a case. The present invention can also be applied to the decentering adjustment structure of the rearmost lens disposed at the rearmost position farthest from the subject.

  FIG. 9 is a cross-sectional view of an example of a lens apparatus for explaining the decentering adjustment structure of the rearmost lens. FIG. 10 is a plan view showing the rearmost lens (master lens 138) and the holding frame (master lens frame 103) of FIG.

  On the outer peripheral side surface of the master lens frame 103 holding the master lens 138, a protrusion 103A is projected along the optical axis 0 direction. The master lens frame 103 is inserted from the rear of the master lens fixing ring 162 as shown by an arrow in FIG. 9 and rotated. Specifically, a rotation jig (not shown) is fitted to the protrusion 103 A of the master lens frame 103, the master lens frame 103 is rotated, and the master lens frame 103 is inserted into the inner periphery of the master lens fixing ring 162. . Thereafter, the corrugated leaf spring 105 and the presser ring 104 are inserted into the inner periphery of the rear end of the master lens fixing ring 162 from behind the master lens frame 103, and the presser ring 104 is screwed to the inner periphery of the master lens fixing ring 162.

  The master lens frame 103 is fixed by being pressed against the contact surface 162A of the master lens fixing ring 162 in the optical axis 0 direction by the presser ring 104. Further, the master lens frame 103 is fitted with a master lens fixing ring 162 disposed on the most optical axis 0 side among the members constituting the lens barrel.

  The corrugated leaf spring 105 interposed between the presser ring 104 and the master lens frame 103 urges the master lens frame 103 toward the contact surface 162A of the master lens fixing ring 162 in the optical axis 0 direction. A concave portion 162 </ b> C corresponding to the projection 105 </ b> A of the corrugated spring 105 is formed on the inner peripheral side surface of the master lens fixing ring 162. The protrusion 105A of the corrugated spring 105 and the concave portion 162C of the master lens fixing ring 162 are fitted, so that the rotation of the corrugated spring 105 about the optical axis 0 is restricted.

  Although the corrugated spring 5 has been described as an example of the annular biasing member, the biasing member is not particularly limited to the corrugated spring, and other biasing members may be used.

  The present invention is not limited to the examples described in the present specification and the examples illustrated in the drawings, and various design changes and improvements may be made without departing from the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 1 ... Lens apparatus, 3 ... Fixed lens frame, 3A ... Gear of fixed lens frame, 4 ... Presser ring, 5 ... Wave plate spring, 5A ... Projection of wave plate spring, 6 ... Adjustment hole cover, 10 ... Front frame ( 10A ... front frame contact surface, 10C ... front frame recess, 10D ... front frame adjustment hole, 12 ... front fixed ring, 14 ... first body ring, 16 ... second Main body ring, 18 ... Rear fixed ring, 20 ... Mount mounting frame, 22 ... Mount ring, 24 ... Lens hood, 30 ... Fixed lens, 70 ... First focus ring, 103 ... Master lens frame, 103A ... Projection of master lens frame 105 ... Corrugated leaf spring, 105A ... Protrusion of corrugated leaf spring, 138 ... Master lens, 162 ... Master lens fixing ring, 162A ... Abutment surface of master lens fixing ring, 162C ... Concave part of master lens fixing ring

Claims (4)

A lens device in which a lens holding frame holding a lens is pressed against and fixed to the lens barrel in the optical axis direction of the lens by a press ring screwed to the inner periphery of the lens barrel;
An annular urging member that is disposed between the presser ring and the lens holding frame and urges the lens holding frame to a contact portion of the lens barrel in the optical axis direction of the lens;
A protrusion is formed on the outer periphery of the biasing member, a recess corresponding to the protrusion of the biasing member is formed on the inner periphery of the lens barrel, and the protrusion of the biasing member and the recess of the lens barrel The lens device is characterized by restricting the rotation of the urging member by engaging with each other.   2. The lens device according to claim 1, wherein a member arranged closest to the optical axis of the lens among members constituting the lens barrel is fitted with the lens holding frame. The lens is a forefront lens disposed at the forefront closest to the subject,
3. The lens according to claim 1, wherein the biasing member and the presser ring are inserted into the lens barrel from the front side of the lens holding frame and are attached to the lens barrel. apparatus. The lens is the rearmost lens arranged at the rearmost position farthest from the subject,
3. The lens according to claim 1, wherein the biasing member and the presser ring are inserted into the lens barrel from behind the lens holding frame and are attached to the lens barrel. apparatus.

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