JP2000266982A - Lens-barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a front lens or an image pickup element from being prostrated because of deformation of a main lens-barrel, by centering a front lens- barrel and a rear lens-barrel comprising different members different from the main lens-barrel out to an optical axis utilizing a guide shaft of a lens holding frame. SOLUTION: One-end parts 9a, 9a of two parallel guide shafts 9, 9 with plural held lens holding frames 6, 7, 8 having movable lenses are press fitted fixedly into press fit bearing holes 10, 10 formed in a front wall face 1a of a main lens-barrel 1 to be penetrated, the other-end parts of the guide shafts 9, 9 are positioned on receiving seats 11, 11 formed in a rear wall 1b of the main lens-barrel 1 to be penetrated, the guide shaft 9, 9 are held on receiving seats 13, 13 by shaft pressing frames 13, 13 provided vertically from a lid lens- barrel 12, and an auxiliary lend-barrel 17 of front lens 16 and an auxiliary lens-barrel 23 of an image pickup element 22 are positioned to be assembled in the guide shafts 9, 9 projected from the front wall face 1a and the rear wall face 1b of the main lens-barrel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel applied to a zoom lens mechanism of, for example, a video camera, and more particularly, to a lens holding frame using a guide shaft of a plurality of lens holding frames having movable lenses. The optical axis of the lens barrel, the front lens, and the image sensor can be easily centered.

[0002]

2. Description of the Related Art A conventional lens barrel of this type is disclosed, for example, in Japanese Patent No. 2775521. According to this, the plurality of lens holding frames constituting the zoom lens mechanism are supported by the guide shaft, and the bearing means of the guide shaft is configured to be supported by bearing recesses formed on the front and rear wall surfaces of the lens barrel. ing.

A front lens disposed in front of the optical axis center of the zoom lens mechanism is attached to a front lens barrel integrally formed with a front part of the lens barrel, and further includes a front lens and a zoom lens. An image sensor that converts a subject image transmitted through the mechanism into an electric signal has a structure supported by a rear barrel integrally formed at the rear of the optical axis center of the lens barrel.

[0004]

By the way, in the above-mentioned conventional lens barrel, a front barrel for a front lens and a rear barrel for an image pickup element are integrated in front and rear portions of the lens barrel. In the molded structure, when the front lens or the imaging element is tilted due to deformation of the lens barrel or the like, there is a problem that the position is shifted from the optical axis center and a normal imaging operation is impaired. Further, if the front lens and the image sensor fall down, correction is not easy.

Further, the lens barrel in which the front barrel and the rear barrel are integrally formed has a problem that the structure is complicated and the manufacturing cost of the mold for forming the lens barrel becomes high. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. The front and rear lens barrels are separate members from the lens barrel, and the front and rear lens barrels are guided. By using the axis to center the optical axis, it is possible to obtain a lens barrel that eliminates the fall of the front lens and the imaging element and that can be manufactured at low cost in the molding die for the lens barrel. The purpose is to:

[0007]

In order to achieve the above-mentioned object, a lens barrel according to the present invention is configured such that one end of a guide shaft holding a plurality of lens holding frames is press-fitted to one side wall surface of a main barrel. So that the other end of the guide shaft is positioned and penetrated on the receiving seat formed on the other side wall surface of the main barrel, and the guide shaft is held on the receiving seat by the shaft holding frame, The auxiliary lens barrel is positioned and assembled to the optical axis center using a guide shaft protruding from the wall surface of the main lens barrel.

[0008] With this configuration, it is easy to position the plurality of lens holding frames and the auxiliary lens barrel attached to the front and rear portions of the main lens barrel with respect to the optical axis center with the guide axis as the axis reference. Therefore, even if the lens barrel is deformed or the like, the guide axis is used as the axis reference, so that the imaging provided in the front lens provided in the front auxiliary barrel or the rear auxiliary barrel is provided. The device can be prevented from falling down.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lens barrel according to the present invention will be described below with reference to the drawings, taking a lens barrel having a zoom lens mechanism as an example.

FIG. 1 is a perspective view showing a state in which components of the lens barrel are separated, FIG. 2 is a sectional view showing an assembled state of the lens barrel, and FIG. 3 is a sectional view taken along line AA of FIG.

The main lens barrel 1 of the lens barrel has a semicircular, substantially boat-like shape, and a zoom lens mechanism 2 is disposed in the main lens barrel 1. The zoom lens mechanism 2 comprises three lenses, the central lens being a fixed lens 3, the subject-side lens (left) being a movable lens 4 (variator lens), and the last lens (right) being movable. Lens 5
(Master lens). And each lens 3, 4,
5 are held by lens holding frames 6, 7, 8 respectively, and the lens holding frames 6, 7, 8 are parallel to each other by holding claws 6a, 7a, 8a and holding cylinders 6b, 7b, 8b provided on the left and right, respectively. The book is supported by guide shafts 9 and 9.

Here, the guide shafts 9, 9 have one end 9 thereof.
a, 9a are press-fitted and fixed in press-fit bearing holes 10, 10 formed in the front wall surface 1a of the main lens barrel 1, and their shaft ends pass through the front wall surface 1a to form a first bearing mechanism. Further, the other end portions 9b, 9b of the guide shafts 9, 9 are supported on V-shaped receiving seats 11, 11 formed on the rear wall surface 1b of the main barrel 1, and the shaft ends thereof pass through the rear wall surface 1b. You. And seat 1
The guide shafts 9, 9 supported on the first, 11 are held by shaft holding arms 13, 13 vertically suspended from a lid-side barrel 12 for closing the opening of the main barrel 1, and serve as a second bearing mechanism. Constitute. The lid-side lens barrel 12 is fixed by screwing a set screw 14 inserted through the hole 12a into a screw hole 1c of the main lens barrel 1.

On the other hand, a window hole 15 is formed in the front wall 1a of the main lens barrel 1.
Is formed, and an auxiliary lens barrel 17 having a front lens 16 serving as a subject lens is attached to the front surface of the front wall surface 1a. That is, the auxiliary lens barrel 17 is positioned after inserting one of the two positioning holes 18, one of which is a long hole, into one end portions 9 a, 9 a of the guide shafts 9, 9 penetrating from the front wall surface 1 a of the main lens barrel 1. The set screw 19 inserted through the hole 17a is screwed and fixed to the screw hole 20 of the front wall surface 1a.

A window hole 21 is also provided in the rear wall 1b of the main lens barrel 1.
Then, an auxiliary lens barrel 23 having an image sensor 22 is attached to the rear surface of the wall surface 1b. That is, the auxiliary lens barrel 23 has two positioning holes 24 and 2 each having a long hole.
Guide shafts 9, 9 that pass through the rear wall 1 b of the main lens barrel 1
After insertion into the other end portions 9b, 9b of the
3a into the screw hole 2 in the rear wall 1b
6 and fixed with screws.

Although not shown here, the two movable lenses 3 and 5 of the zoom lens mechanism 2 have their respective lens holding frames 6 and 8 movable in the optical axis direction by a driving force of a pulse motor or the like so that the zoom lens can move. Is performed. The iris mechanism is, for example, a main lens barrel 1 or a lid lens barrel 1.
2 is formed with a slit, from which it can be inserted between the lenses of the zoom lens mechanism.

The procedure for assembling the lens barrel having the above-described structure is as follows.
7 and 8, the other end portions 9b, 9b of the guide shafts 9, 9 are connected to the receiving seats 11, 9 on the rear wall surface 1b of the main lens barrel 1.
11 side, and one end 1a, 1 of the guide shaft 9, 9
a is press-fitted and fixed while penetrating through the press-fit bearings 10, 10 of the front wall surface 1 a of the main barrel 1. Thereafter, the cover lens barrel 12 is assembled to the main lens barrel 1, and the guide shafts 9, 9 are pressed from above by the shaft holding arms 13, 13 and held on the receiving seats 11, 11.
Thereafter, guide shafts 9 projecting from the front and rear wall surfaces of the main lens barrel 1,
The assembly is completed by positioning and fixing the auxiliary lens barrel 17 including the front lens 16 and the auxiliary lens barrel 23 including the image sensor 22 to the lens 9.

The lens barrel according to the present invention having the above-described configuration has the centering of the lens holding frames 6, 7, 8 on the optical axis L with respect to the two guide shafts 9, 9 as well as the front lens. The centering of the auxiliary barrel 17 of the lens 16 and the auxiliary barrel 23 of the imaging device 22 with respect to the optical axis L can be accurately performed, and high optical performance can be easily obtained. In addition, since the auxiliary lens barrel 17 of the front lens 16 and the auxiliary lens barrel 23 of the image pickup device 22 are separate members and are positioned and fixed to the front and rear wall surfaces of the main lens barrel 1, the main lens barrel 1 is deformed. Even if this occurs, the front lens 16 and the image sensor 22 do not fall because the positioning on the optical axis is based on the guide shaft 9 as an axis reference.

A main lens barrel 1 and two auxiliary lens barrels 17, 2
Since the moldings 3 are formed separately, the molding dies for the respective lens barrels are simplified, and the molding cost can be reduced.

Furthermore, since two guide shafts 9 having the same shaft diameter and length are used, only one type of guide shaft is required, and the cost of parts can be reduced.

The receiving seat 11 of the guide shaft 9 described above is shown in FIG.
As shown in FIG. 4B, the guide shaft 9 is not limited to the V-shape. If the guide shaft 9 is positioned in a direction perpendicular to the optical axis, a U-shaped receiving seat 27 as shown in FIG. 4c, a semicircular receiving seat 28 as shown in FIG.
As shown in FIG. 4D, the receiving seat 29 may have a square groove shape.

An auxiliary lens barrel 23 provided with an image sensor 22
As another embodiment of the positioning means, as shown in FIG. 5, press-fit bearing holes 30, 30 formed in an auxiliary lens barrel 23 in two guide shafts (not shown) which are supported by the receiving seats 11, 11 and penetrate therethrough. And the positioning holes 32, 32 formed in the auxiliary lens barrel 23 are inserted into the protruding shafts 31, 31 projecting from the rear wall surface 1b of the main lens barrel 1, and the auxiliary lens barrel 23
After the positioning of the auxiliary barrel 2, the set screw 25 is screw-fixed to the screw hole 26 of the rear wall surface 1 b of the main barrel 1 through the hole 23 a as in the case of the above-described embodiment.
3 can be centered on the optical axis. With such a configuration, the shaft holding arm 13 can be made unnecessary.

The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

In this embodiment, as the means for fixing the guide shafts 9, 9, press-fit bearing holes 10, 1 are formed on the front wall surface 1 a side of the main lens barrel 1.
0 and press-fitted and fixed to the bearing seats 11 on the rear wall surface 1b side.
The same effect can be obtained by press-fitting and fixing to the press-fit bearing hole on the rear wall surface 1b side and bearing the receiving seat on the front wall surface 1a side.

Further, the lens barrel of the present invention is not limited to a video camera apparatus, but can be widely applied to a lens barrel of an electronic apparatus using a movable lens or the like.

[0025]

As described above, in the lens barrel according to the present invention, one end of the guide shaft holding a plurality of lens holding frames is pressed into and supported by one side wall surface of the main barrel, and penetrates. The other end side of the guide shaft is positioned on the receiving seat on the other side wall surface of the main barrel and penetrates, and the guide shaft is held on the receiving seat by the shaft holding arm, and the guide shaft which projects through is used. By positioning and assembling the auxiliary lens barrel at the front and rear of the main lens barrel, a plurality of lens holding frames and the auxiliary lens barrel mounted at the front and rear parts of the lens barrel with the guide axis as the axis reference. There is an effect that positioning to the optical axis center can be performed accurately and easily, and high optical performance can be obtained.

Further, even if the main barrel is deformed, since the guide axis is used as an axis reference, it is possible to prevent the auxiliary barrel from falling down and to avoid a deviation of the optical axis between the main barrel and the auxiliary barrel. be able to.

Further, since the main lens barrel and the two auxiliary lens barrels are formed separately from each other, the molds for the respective lens barrels are simplified, and the mold cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a separated state of a lens barrel according to the present invention.

FIG. 2 is a sectional view of an assembled state of the lens barrel according to the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4A is a view showing a case where a receiving seat of a guide shaft is V-shaped. b is a diagram in the case where the bearing seat of the guide shaft has a U-shape title. c is a diagram in the case where the receiving seat of the guide shaft has a semicircular shape. d is a diagram in the case where the receiving seat of the guide shaft has a square groove shape.

FIG. 5 is a perspective view of another positioning structure of the auxiliary lens barrel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main lens barrel, 2 ... Zoom lens mechanism, 6, 7, 8 ... Lens holding frame, 9 ... Guide shaft, 10 ... Press-fit bearing hole, 11 ... Receiving seat, 12 ... Lid barrel, 13 ... Shaft holding arm, Reference numeral 16: front lens, 17: auxiliary lens barrel, 18: positioning hole, 22: imaging element, 23: auxiliary lens barrel, 24: positioning hole, 27, 2
8, 29: receiving seat, 30: press-fit bearing hole, 31: protruding shaft, 3
2 ... Positioning hole

Claims (3)

[Claims] 1. A lens barrel in which a plurality of lens holding frames having at least a movable lens are held by a guide shaft, and wherein the movable lens is movable in an optical axis direction along the guide axis. A first bearing mechanism in which one end of the guide shaft is press-fitted and supported on one side wall surface of the main barrel, and the guide shaft has another end formed on the other side wall surface of the main barrel; A second bearing mechanism which is positioned on the seat and penetrates, and wherein the guide shaft is held on the receiving seat by a shaft holding arm. The first bearing mechanism and the second bearing mechanism A lens barrel characterized in that auxiliary barrels are positioned and assembled at the front and rear on the optical axis of the main barrel using the guide shafts which respectively penetrate and protrude from the lens barrel. 2. The lens barrel according to claim 1, wherein an auxiliary barrel is press-fitted and supported on the guide shaft penetrating from the second bearing mechanism, and protruding from the other side wall surface of the main barrel. A lens barrel characterized in that an auxiliary lens barrel is positioned in the lens barrel. 3. The lens barrel according to claim 1, wherein said auxiliary lens barrel is a lens barrel for a front lens and a lens barrel for an image sensor.