JP2014071179A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a tracking adjustment and a tilt adjustment in a lens barrel.SOLUTION: In a lens barrel including a barrel 10 defining a reference optical axis L and a lens holding frame 20 being connected/fixed to the barrel with a lens held, the barrel 10 has a female thread 15 formed on an inner peripheral surface of the barrel, and the lens holding frame 20 has a male screw 23 formed on an outer peripheral surface of the barrel to engage with the female thread of the barrel. The male screw 23 and the female thread 15 are formed such that the male screw 23 and the female thread 15 are engaged with each other with a predetermined gap between each thread and each screw groove. Accordingly, the male screw 23 is engaged with the female thread 15 to adjust an engagement amount, and thereby a position of the lens in a direction of the reference optical axis is adjusted (a tracking adjustment) and further, a play due to the gap between the male screw 23 and the female thread 15 is used to tilt the lens holding frame 20 as necessary, and thereby the tilt of the lens with respect to the reference optical axis can be adjusted.

Description

  The present invention relates to a lens barrel to which a lens holding frame that holds a lens is attached to a lens barrel that defines a reference optical axis, and in particular, a position and a reference in a reference optical axis direction of a lens held by the lens holding frame. The present invention relates to a lens barrel capable of adjusting an inclination with respect to an optical axis.

Conventional lens barrels include a lens barrel (first group cylinder) that defines a reference optical axis, a lens holding frame (first group lens chamber) that holds and fixes the lens, and a lens holding frame. An intermediate cylinder interposed between the lens barrel and the lens barrel, and a male screw is provided on the outer periphery of the lens holding frame, and an inner screw is provided on the inner circumference of the intermediate cylinder to be engaged with the male screw of the lens holding frame. The lens holding frame is rotated while the intermediate tube is temporarily fixed to the lens barrel to adjust the position of the lens in the reference optical axis direction. After that, it is known that the intermediate cylinder is rotated to adjust the angular position around the reference optical axis of the lens, and finally the intermediate cylinder is fixed to the lens barrel (for example, Patent Document 1). reference).
However, in this lens barrel, adjustment of the position of the lens in the reference optical axis direction (focus adjustment) and adjustment of the angular position around the reference optical axis of the lens (adjustment of focal plane asymmetry) are performed in separate steps. Adjustment work is troublesome, and even if the position adjustment in the reference optical axis direction and the angular position around the reference optical axis can be performed, the tilt adjustment (tilt adjustment) of the lens with respect to the reference optical axis is performed. It is not possible.

Other lens barrels include a lens barrel (adjustment frame and reference frame) that defines a reference optical axis (reference axis), a lens holding frame (lens) that holds the lens and is fixed in the lens barrel. Frame) and provided with five adjustment surfaces that are convexly curved and stepped at three locations on the outer peripheral surface (120 degree interval) of the lens holding frame, and three locations on the inner peripheral surface of the lens barrel ( 120 ° intervals), three receiving surfaces for supporting the lens holding frame by contacting any of the five adjusting surfaces provided on the lens holding frame are provided, and the lens holding frame is provided on the receiving surface of the lens barrel. The lens holding frame is adjusted in a state where the lens is adjusted (tracking adjustment) in the reference optical axis direction by contacting any of the five adjustment surfaces, and the adjustment surface is in contact with the receiving surface of the lens barrel. Tilting the lens optical axis with respect to the reference optical axis Those to perform the tilt adjustment (tilt adjustment) with respect to the reference light axis of the lens is known (e.g., see Patent Document 2).
However, in this lens barrel, both position adjustment (tracking adjustment) and tilt adjustment (tilt adjustment) in the reference optical axis direction can be performed, but the position adjustment in the reference optical axis direction is performed in five steps. Select one of the adjustment surfaces, that is, only a limited number of steps can be adjusted, and it cannot be continuously adjusted. Therefore, position adjustment (tracking adjustment) is performed at the optimum position. Could not do.

JP 2003-5006 A JP 2010-66720 A

  The present invention has been made in view of the above circumstances, and its object is to adjust the position in the direction of the reference optical axis (tracking) while simplifying the structure, reducing the number of parts, and reducing the size. Adjustment, focus adjustment) and inclination adjustment (tilt adjustment) with respect to the reference optical axis can be smoothly performed without requiring special setup, and position adjustment in the reference optical axis direction can be continuously performed. The object is to provide a lens barrel.

The lens barrel of the present invention is a lens barrel that includes a lens barrel that defines a reference optical axis, and a lens holding frame that holds the lens and is connected and fixed to the lens barrel. The lens holding frame has a male screw formed on its outer peripheral surface so as to be screwed into the female screw of the lens barrel, and the male screw and the female screw are: It is characterized by being formed so as to be screwed with a predetermined gap between each screw thread and the screw groove.
According to this configuration, the lens holding frame holding the lens is brought close to the lens barrel, the male screw of the lens holding frame is screwed to the female screw of the lens barrel, and the screwing amount is adjusted as appropriate, so that the reference light is obtained. Lens position adjustment (tracking adjustment) in the direction of the axis can be performed continuously, and at that adjustment position, using a play (tilt adjustment allowance) due to a predetermined gap between the male screw and the female screw. By tilting the lens holding frame as appropriate with respect to the reference optical axis, tilt adjustment (tilt adjustment) of the lens (optical axis) with respect to the reference optical axis can be performed.
In this way, in the relationship between the male screw of the lens holding frame and the female screw of the lens barrel, it merely forms a predetermined gap that may cause a backlash different from the screwed relationship between the standard male screw and the female screw. Simplification, reduction of the number of parts, miniaturization, etc. can be achieved.

In the above configuration, the lens holding frame may employ a configuration having a jig mounting portion for detachably mounting a jig used when connecting to the lens barrel.
According to this configuration, with the jig attached to the jig mounting portion, the lens holding frame is brought close to the lens barrel, and the male screw is engaged with the female screw to adjust the position in the reference optical axis direction (tracking adjustment). Then, by tilting the jig appropriately, tilt adjustment (tilt adjustment) of the lens holding frame (lens) with respect to the reference optical axis can be performed, so that both adjustment operations can be performed easily and smoothly.

In the above configuration, the lens holding frame and the lens barrel adopt a configuration in which the lens holding frame is formed so as to define an adhesive reservoir portion into which an adhesive can be injected in a state where the lens holding frame is connected to the lens barrel. Can do.
According to this configuration, after the position adjustment (tracking adjustment) in the reference optical axis direction and the inclination adjustment (tilt adjustment) with respect to the reference optical axis, a desired adhesive is injected into the adhesive reservoir to maintain the adjustment state. As it is, the lens holding frame can be firmly fixed to the lens barrel.

In the above configuration, the male screw is composed of a plurality of male screws formed apart from each other in the circumferential direction of the lens holding frame, and the lens holding frame is formed between the plurality of male screws in the circumferential direction. The structure which has the recessed part which makes a part of can be employ | adopted.
According to this configuration, the outer periphery of the lens holding frame is formed with a recess for injecting an adhesive between the male screws and the male screws at intervals in the circumferential direction. Thus, the lens holding frame can be connected and fixed evenly in the circumferential direction in the adjusted state.
In addition, by providing a plurality of male screws spaced apart in the circumferential direction, it is possible to more effectively adjust the inclination in a state of being screwed with the female screw as compared with the case where the male screws are provided over the entire circumference.

  According to the lens barrel having the above configuration, position adjustment (tracking adjustment, focus adjustment) in the reference optical axis direction and inclination adjustment with respect to the reference optical axis are achieved while simplifying the structure, reducing the number of parts, and reducing the size. (Tilt adjustment) can be performed smoothly without requiring special setup, and position adjustment in the reference optical axis direction can be performed continuously.

1 is an exploded perspective view showing an embodiment of a lens barrel according to the present invention. It is sectional drawing which shows one Embodiment of the lens-barrel which concerns on this invention. FIG. 2 shows a screwed relationship between a male screw provided in a lens holding frame of a lens barrel and a female screw provided in the lens barrel according to the present invention, and (a) shows a lens holding frame as a reference optical axis thereof. ) Is a partial cross-sectional view showing a state in which the lens holding frame is tilted counterclockwise in the figure, and (b) shows a state in which the lens holding frame is tilted clockwise in the figure with respect to the lens barrel (reference optical axis thereof). It is a fragmentary sectional view. It is a disassembled perspective view which shows the state which attached the jig to the lens holding frame when the lens barrel which concerns on this invention is assembled | attached. It is sectional drawing which shows the state which assembled | attached the lens barrel which concerns on this invention using the jig. It is a partial expanded sectional view explaining inclination adjustment at the time of attaching the lens barrel concerning the present invention. It is a partial expanded sectional view explaining inclination adjustment at the time of attaching the lens barrel concerning the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, the lens barrel according to this embodiment includes a lens barrel 10 that defines a reference optical axis L, and a lens holding frame 20 that is connected and fixed to the lens barrel 10.
The lens barrel 10 is provided at the tip of a zoom lens barrel including a plurality of lens barrels, and demarcates a reference optical axis L positioned coaxially with an optical axis of a lens included in another lens barrel. As shown in FIGS. 1 and 2, the outer cylindrical portion 11, the inner cylindrical portion 12 coaxial with the outer cylindrical portion 11, the circular opening 13 and the annular flange portion 14 formed in the inner cylindrical portion 12, and the inner cylindrical portion 12. Female threads 15 and the like formed on the inner peripheral surface.

The outer cylindrical portion 11 is formed so as to be connected to another lens barrel (not shown) and movably supported in the direction of the reference optical axis L when constituting the zoom lens barrel.
As shown in FIG. 2, the inner cylindrical portion 12 is formed as a region for accommodating and fixing the lens holding frame 20.
As shown in FIG. 2, the opening 13 is formed to have a size for receiving the rear end region of the lens holding frame 20 in contact.
As shown in FIG. 2, the annular flange 14 abuts the rear end surface 22 b of the arc-shaped protruding portion 22 of the lens holding frame 20 when the lens holding frame 20 is screwed into the reference optical axis. It is formed so as to define the moving end of the lens holding frame 20 in the L direction.
As shown in FIG. 2, the female screw 15 is formed on the inner peripheral surface of the inner cylindrical portion 12, and is formed so as to be screwed with the male screw 23 of the lens holding frame 20 with a predetermined gap. .

  As shown in FIGS. 1 and 2, the lens holding frame 20 is formed in an annular shape, and is formed in a multistage shape having different inner diameters so as to fit and hold the lenses G1, G2, and G3, respectively. The combined holding portion 21, three arc-shaped protrusions 22 formed at equal intervals (120-degree intervals) in the circumferential direction on the outer peripheral surface thereof, and three male screws 23, 3 formed on the arc-shaped protrusion 22 (outer peripheral surface thereof) A concave tooth row portion 24 as a concave portion formed between two arc-shaped protruding portions 22 (three male screws 23) and forming a part of the adhesive reservoir, and three arc-shaped protruding portions 22 (three male screws 23) And three jig mounting portions 25 formed as concave grooves between the three concave tooth row portions 24 and the like.

As shown in FIG. 2, the fitting holding part 21 is fitted with a first fitting holding part 21a for fitting and holding the lens G1, a cylinder part 21b for receiving the lens G2 joined to the lens G1, and a lens G3. It is formed so as to include the second fitting holding portion 21c to hold.
As shown in FIG. 1, the three arcuate protrusions 22 have a circumferential length substantially forming a predetermined center angle (about 60 degrees) in a region equally divided into three in the circumferential direction of the lens holding frame 20. It is formed to have a rectangular cross section.

As shown in FIG. 1, the three male screws 23 are formed on the outer peripheral surface of each arcuate protrusion 22, and are formed so as to be screwed with the female screw 15 of the lens barrel 10 with a predetermined gap. ing.
Here, the screwed relationship between the male screw 23 and the female screw 15 is such that the lens holding frame 20 is opposite to the lens barrel 10 in FIG. 3A as shown in FIGS. When tilted clockwise, there is a predetermined gap between the thread 23a of the male screw 23 and the screw groove 15a of the female screw 15, and the lens holding frame 20 is shown in FIG. ), When it is tilted clockwise, a relationship of being threaded with a predetermined gap between the thread 23a of the male screw 23 and the screw groove 15a of the female screw 15 is obtained. In a state in which the female screw 15 is screwed, the backlash is formed between the two.
Here, by providing the male screw 23 at three positions apart in the circumferential direction, the tilt adjustment of the lens holding frame 20 in a state where it is screwed with the female screw 15 is more adjusted than in the case where it is provided over the entire circumference. Can be done effectively.

As shown in FIG. 1, the three concave tooth row portions 24 have circumferential lengths that form a predetermined central angle (about 50 degrees) in each of the regions that are equally divided into three in the circumferential direction of the lens holding frame 20. It is formed at a height that does not protrude from the male screw 23 in the radial direction (a height that allows the male screw 23 to be engaged with the female screw 15).
Then, the concave tooth row portion 24 is an adhesive reservoir portion that can inject an adhesive between the lens holding frame 20 and the female screw 15 of the lens barrel 10 in a state where the lens holding frame 20 is screwed and connected to the lens barrel 10. Are defined.

Thus, by providing the concave tooth row portion 24 that forms a part of the adhesive reservoir, position adjustment (tracking adjustment) in the reference optical axis L direction and inclination adjustment (tilt adjustment) with respect to the reference optical axis L can be performed. Later, by injecting a desired adhesive into the concave tooth row portion 24, the lens holding frame 20 can be firmly fixed to the lens barrel 10 while maintaining the adjusted state.
In addition, concave tooth row portions 24 as concave portions forming a part of the adhesive reservoir portion are provided at three positions at intervals in the circumferential direction, that is, at intervals on the outer periphery of the lens holding frame 20 in the circumferential direction. In addition, since a recess for injecting an adhesive is formed between the plurality of male screws 23, the lens holding frame 20 is connected and fixed evenly to the lens barrel 10 in the circumferential direction. Can do.

  As shown in FIGS. 1 and 4, the three jig mounting portions 25 each have a predetermined center angle (about 5 to 10 degrees) in a region divided into three equal parts in the circumferential direction of the lens holding frame 20. In addition, it is formed as a concave groove that is thinned in the direction of the reference optical axis L. When the lens holding frame 20 is connected to the lens barrel 10 and the position is adjusted, the engaging claw T3 of the jig T is detachably fitted. Be able to.

As shown in FIGS. 4 and 5, the jig T is formed at the tip of the annular gripping portion T1, the three engaging arms T2 extending from the gripping portion T1 in the reference optical axis L direction, and the engaging arms T2. An engagement claw T3 is provided.
As shown in FIGS. 4 and 5, the engaging claw T3 abuts on the front end surface 22a of the arc-shaped protruding portion 22 of the lens holding frame 20 and faces the engaging arm T2 radially outward with respect to the jig mounting portion 25. It is formed so as to be fitted so as to be slightly expanded.

  In this way, by providing the lens holding frame 20 with the jig mounting portion 25 on which the jig T can be mounted, the lens holding frame 20 is brought close to the lens barrel 10 while the jig T is mounted on the jig mounting portion 25. Position adjustment (tracking adjustment) in the direction of the reference optical axis L is performed while the male screw 23 is screwed to the female screw 15, and then the jig T is appropriately tilted, whereby the lens holding frame 20 (lenses G1, G2 with respect to the reference optical axis L). , G3) can be adjusted (tilt adjustment), so that both adjustment operations can be performed easily and smoothly.

According to the lens barrel having the above configuration, the lens holding frame 20 holding the lenses G1, G2, and G3 is brought close to the lens barrel 10, and the female screw 23 of the lens holding frame 20 is screwed onto the female screw 15 of the lens barrel 10. The positions of the lenses G1, G2, G3 in the direction of the reference optical axis L can be adjusted by adjusting the screwing amount as appropriate, and the male screw 23 and the female screw 15 can be adjusted at the adjustment position. The lens holding frame 20 is appropriately tilted with respect to the reference optical axis L by using a backlash (tilt adjustment allowance) due to a predetermined gap between the lenses G1, G2, G3 (the optical axes of the lenses G1, G2, G3) with respect to the reference optical axis L ) Can be adjusted.
As described above, the relationship between the male screw 23 of the lens holding frame 20 and the female screw 15 of the lens barrel 10 is merely to form a predetermined gap that may cause a backlash that is different from the screwing relationship between the standard male screw and the female screw. Therefore, simplification of the structure, reduction of the number of parts, miniaturization, etc. can be achieved.

Next, an assembling operation and an adjusting operation (position adjustment in the direction of the reference optical axis L, inclination adjustment with respect to the reference optical axis L) will be described.
First, the lens barrel 10, the lens holding frame 20 holding the lenses G1, G2, and G3, the jig T, and the adhesive are prepared.

Subsequently, as shown in FIG. 4, the engaging claws T <b> 3 of the jig T are fitted into the jig mounting portion 25 of the lens holding frame 20, and the lens holding frame 20 is held by the jig T.
Subsequently, in this state, the lens holding frame 20 is brought close to the lens barrel 10 from the front side, and the holding portion T1 of the jig T is held and rotated so that the male screw 23 is screwed into the female screw 15.

  Here, while confirming an image photographed through the lenses G1, G2, and G3 on a monitor or the like, the lens holding frame 20 is screwed in until the subject is in focus, whereby the reference optical axis L direction of the lenses G1, G2, and G3 is adjusted. Position adjustment (tracking adjustment) is performed, and then, while checking the monitor, the jig T is appropriately tilted, for example, counterclockwise as shown in FIG. 6 or clockwise as shown in FIG. So that the four corners of one-sided blur can be balanced (one-sided blur disappears) by inclining (by changing the amount of inclination within a range of backlash caused by a predetermined gap between the male screw 23 and the female screw 15). Adjust the tilt (tilt adjustment).

Thereafter, the adhesive is injected into and fixed to the concave dentition part 24, and then the jig T is pulled out in the direction of the reference optical axis L to adjust the position of the lenses G1, G2, G3 in the reference optical axis L direction (tracking adjustment). In addition, the lens holding frame 20 can be firmly fixed to the lens barrel 10 in a state where the inclination adjustment (tilt adjustment) of the lenses G1, G2, and G3 with respect to the reference optical axis L is completed.
As the adhesive, an ultraviolet curable adhesive or a thermosetting adhesive can be used.

  As described above, according to the lens barrel having the above-described configuration, position adjustment (tracking adjustment, focus adjustment) in the direction of the reference optical axis L is achieved while achieving simplification of the structure, reduction in the number of parts, miniaturization, and the like. And tilt adjustment (tilt adjustment) with respect to the reference optical axis L can be performed smoothly without requiring special setup, and position adjustment in the reference optical axis L direction can be performed continuously.

In the above embodiment, a double cylindrical shape having the outer cylindrical portion 11 and the inner cylindrical portion 12 provided with the female screw 15 is shown as the lens barrel. However, the present invention is not limited to this, and a single cylindrical mirror is shown. It may be a tube or a lens barrel that holds a plurality of other lenses.
In the above embodiment, the case where the three male screws 23 are provided in three regions equally divided in the circumferential direction of the outer peripheral surface of the lens holding frame 20 is shown, but the present invention is not limited to this. You may provide the external thread divided | segmented above.
In the above-described embodiment, the case where an adhesive is used as a method for fixing the lens holding frame 20 to the lens barrel 10 after adjustment has been described. However, the present invention is not limited to this. You may fix using a fixing means.

  As described above, the lens barrel according to the present invention achieves position simplification (tracking adjustment, focus adjustment) and reference in the direction of the reference optical axis L while achieving simplification of the structure, reduction in the number of parts, miniaturization, and the like. The tilt adjustment (tilt adjustment) with respect to the optical axis L can be performed smoothly without requiring special setup, and the position adjustment in the direction of the reference optical axis L can be continuously performed. Of course, the present invention can be applied to a camera provided with a barrel, and is also useful in an optical device other than a camera.

L Reference optical axis 10 Lens barrel 11 Outer cylindrical portion 12 Inner cylindrical portion 13 Opening portion 14 Annular flange 15 Female screw 15a Screw groove 20 Lens holding frame G1, G2, G3 Lens 21 Fitting holding portion 21a First fitting holding portion 21b Cylindrical part 21c 2nd fitting holding part 22 Arc-shaped protrusion part 22a Front end surface 22b Rear end surface 23 Male screw 23a Thread 24 Recessed tooth row | line | column part (a recessed part, a part of adhesive reservoir part)
25 Jig mounting part T Jig T1 Holding part T2 Engaging arm T3 Engaging claw

Claims (4)

A lens barrel that includes a lens barrel that defines a reference optical axis, and a lens holding frame that holds and fixes the lens to the lens barrel;
The lens barrel has a female screw formed on its inner peripheral surface,
The lens holding frame has a male screw formed on an outer peripheral surface thereof to be screwed into a female screw of the lens barrel,
The male screw and the female screw are formed so as to be screwed with a predetermined gap between each screw thread and screw groove,
A lens barrel characterized by that. The lens holding frame has a jig mounting portion for detachably mounting a jig used when connecting to the barrel.
The lens barrel according to claim 1. The lens holding frame and the lens barrel are formed so as to define an adhesive reservoir portion into which an adhesive can be injected in a state where the lens holding frame is connected to the lens barrel.
The lens barrel according to claim 1 or 2, wherein The male screw is composed of a plurality of male screws formed apart from each other in the circumferential direction of the lens holding frame,
The lens holding frame has a recess formed between the plurality of male screws in the circumferential direction and forming a part of the adhesive reservoir.
The lens barrel according to claim 3.

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