JP3456785B2 - Camera lens barrel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for a camera, and more particularly to a structure of a driving mechanism for setting photographing conditions in a lens barrel used for a small camera.

[0002]

2. Description of the Related Art A lens barrel of a camera including a small camera and an ultra-small camera is equipped with an aperture mechanism, a focus mechanism, a zoom mechanism and the like for setting photographing conditions.
FIG. 8 shows an example of a lens barrel of a microminiature camera used as a surveillance camera or the like.

In FIG. 8, a lens frame 3 holding a rear lens group 2 is provided inside a main barrel 1 of a lens barrel.
A lens frame 5 holding a front lens group 4 is attached to the front end side (left side in the drawing) of the main body cylinder 1. A diaphragm drive unit, which is a combination of a plurality of diaphragm blades 6 and a chrysanthemum 7, is arranged between the front lens group 4 and the rear lens group 2, and an iris ring 8 is provided on the outer periphery of the main body cylinder 1. It is rotatably provided. A guide groove is formed in the chrysanthemum seat 7, and an engagement pin (dowel pin) 9 (only one is shown in the drawing) provided on the diaphragm blade 6 is engaged with the guide groove. . A connecting screw 10 is attached to the chrysanthemum 7 and the head of the connecting screw 10 has an iris ring 8
Is engaged with the inner peripheral portion of the.

According to the above construction, when the iris ring 8 is rotated, the chrysanthemum 7 is rotated via the connecting screw 10.
The engaging pin 9 engaged with the guide groove of the chrysanthemum 7 moves in the radial direction. Therefore, the diaphragm blade 6 is moved in association with the movement of the pin 9, and the diaphragm aperture amount is adjusted and controlled by driving the plurality of diaphragm blades 6.

[0005]

By the way, in the lens barrel as described above, simplification of the structure and cost reduction are required, and further miniaturization of the camera is required. For example, in the example of FIG. 8 described above, after the iris ring 8 is attached to the main body cylinder 1, the lens frame 5 is screwed and coupled to the inner circumference of the main body cylinder 1. Therefore, in this case, since the iris ring 8 is arranged, the lens frame 5 of the front lens group 4 is separated from the main body cylinder 1, which results in an increase in the number of parts.

The present invention has been made in view of the above points, and an object thereof is to simplify the structure and reduce the cost.
It is an object of the present invention to provide a lens barrel for a camera, which can reduce the diameter of a micro camera.

[0007]

[Means for Solving the Problems] To achieve the above object
The invention according to claim 1Lens barrel for camera
On the outer circumference of the main body cylinder that holds the lens.Placed and slabs
It can be bent in a cylindrical shape and the diameter of the cylinder can be changed at its mating end.
It consists of a thin plate ring that is opened,
It can be attached to the outer circumference of the main body while expanding the endShooting condition setting
Regular drive ringAnd both open ends of this drive ring
Has a groove for engaging the U-shaped opening formed at the open end.
Connect the drive ring to the drive member inside the main body cylinder.
And a connecting screw forCharacterized by
To do. The invention according to the second aspect is for the drive ring position.
Mount the lens groups that are arranged front and back to the integrally formed main body cylinder
Hold it and fit the drive ring on the outer circumference of this body cylinder.
It is characterized by doing so.

[0008]

According to the above construction, the drive ring can be arranged as an aperture ring, a focus ring, a zoom ring or the like. The drive ring of this thin plate is fitted into the main body cylinder while widening the open end serving as the mating portion, that is, with the ring inner diameter slightly larger than the outer diameter of the main body cylinder. Then, for example, when using it as a diaphragm ring,
In order to drive the diaphragm blades, driving members such as <br/> chrysanthemum with connecting screw is coupled to the diaphragm ring having the engagement groove. Since this diaphragm ring can have a thickness of 0.5 mm or less, its outer diameter can be made smaller than that of a conventional diaphragm ring having a thickness of 0.5 mm or more. Will reduce the overall diameter of the lens barrel.
In addition, the open end of the aperture ring or
By engaging the U-shaped opening, the diaphragm ring and the chrysanthemum seat
Are firmly connected and fixed.

Further, according to the structure of the second aspect, since the drive ring having a variable diameter is used, the lens barrel having the structure in which the lens groups before and after the drive ring are held in the integrally formed main body cylinder,
There is the advantage that the drive ring can be attached .

[0010]

EXAMPLE FIG. 1 shows a lens barrel for a camera according to Example 1, FIG. 2 (A) shows a cross section taken along line II-II of FIG. 1, and FIG. The open end portion of the iris ring (diaphragm ring) is shown, the overall view of the iris ring is shown in FIG. 3, and the configuration of the diaphragm blades is shown in FIG. The embodiment is a lens barrel for a micro camera having the same configuration as that shown in FIG. 8, and the present invention is applied to this iris ring. In FIG. 1, in the main body cylinder 12, a holding frame 3 for holding the rear lens group 2 is screwed, and the front lens group 4 is directly attached. In the lens barrel of the embodiment, the focal length in the focusing function is fixed within a predetermined range. Then, the iris ring 14 is provided in a predetermined groove portion on the outer periphery of the main body cylinder 12.
Is attached.

As shown in FIG. 3, the iris ring 14 is formed by curling a thin plate made of metal or plastic and having a thickness of 0.5 mm or less into a cylindrical shape.
The mating end is formed to be the open end H. Therefore,
The iris ring 14 can be attached to the main body cylinder 12 in a state where the open end H is widened to increase the cylinder diameter. Further, a circular engagement hole 16 is formed in the iris ring 14, and the head portion of the connecting screw (iris limiting screw) 17 of FIG. 1 is engaged with the engagement hole 16.

As shown in the drawings, the connecting screw 17 is screwed and fixed to the side surface of the chrysanthemum seat 7 arranged in the main body cylinder 12, and by operating the iris ring 14, the chrysanthemum seat 7 rotates in the range of the angle θ shown in FIG. 2, for example. The chrysanthemum 7 has an opening 19 at its center and three guide grooves 20 on the front surface. Then, on the front side of the chrysanthemum 7, as shown in FIG. 4, three diaphragm blades 21 are arranged,
One end of the diaphragm blade 21 is rotatably supported by the front plate by a support pin 22, and an engaging pin 23 that engages with the guide groove 20 is attached to the other end. Therefore, in FIG. 4, the chrysanthemum 7 rotates clockwise to drive the three diaphragm blades 21 so that the diaphragm opening 100 becomes smaller.

According to this structure, the iris ring 14 is formed of a thin plate having a thickness of 0.5 mm or less. Therefore, as compared with the structure shown in FIG. By reducing the outer diameter, it is possible to further reduce the outer diameter of the micro lens barrel. In addition, in the above embodiment, all the lenses are used as the main barrel 1.
Since it is not necessary to hold the front lens group 4 in the separately formed lens frame 5 as in the configuration of FIG. 8, the number of parts is reduced and the lens frame 5 is screwed and coupled. Since the structure is unnecessary, the structure is simplified.

5 to 7 show another example of the structure for connecting the iris ring to the connecting screw. In the iris ring 25 of the second example of FIG. 5, engaging holes 26 are formed at both ends of the mating portion of the open end H, and the engaging hole 26 of this mating portion is engaged with the connecting screw 17. . Also,
In the third example of FIG. 6, a connecting screw 28 having an engaging groove 27 formed in the circumferential direction is provided in the middle abdomen, and an iris ring 29 is provided.
A fixing portion 30 formed of a U-shaped opening is formed on one side of the open end H of the. Therefore, in this case, the fixing portion 30 is fitted into the engaging groove 27 of the connecting screw 28, so that the iris ring 29 and the connecting screw 28 are connected.

In the fourth example of FIG. 7, the open end H of the iris ring 31 is directly connected to the connecting screw 28 described above. That is, the opposite ends at the open end H are fitted and fixed in the engaging groove 27 of the connecting screw 28,
The iris ring 31 does not need to be provided with the engagement hole. 6 and 7 described above has an advantage that the coupling screw 28 and the iris rings 29 and 31 are firmly coupled. Although the open end H in each of the above examples has a small gap between both ends, the iris rings 14, 25, 2 are arranged so that the both ends overlap.
You may comprise 9,31.

In the above embodiment, an example in which the present invention is applied to the aperture ring is shown. However, when the lens barrel is provided with a focus drive mechanism and a zoom drive mechanism, the focus ring and the zoom ring for operating them are provided. The ring can also be formed by bending a thin plate into a cylindrical shape, and opening the end of the ring so that the cylindrical diameter can be varied.

[0017]

As described above, according to the first aspect of the invention, the thin plate is formed into a cylindrical shape, and its mating end is formed.
Is it a thin plate ring opened so that the cylinder diameter can be changed?
The outer periphery of the main body cylinder while expanding the mating open end.
A drive ring that can be attached to set the shooting conditions and this drive ring.
Both open ends of the ring or a U-shaped opening formed at this open end
It has a groove that engages the mouth, and drives the drive ring and the inside of the main barrel.
Since it has a connecting screw for connecting the moving member ,
Compared with a conventional drive ring formed by cutting a pipe-shaped member, the drive ring can be formed to be thin, and the diameter can be further reduced in an ultra-small camera or the like. Then, fix the drive ring in the groove of the connecting screw.
Since the parts are engaged, the drive ring is firmly connected.
There is an advantage to be.

According to the second aspect of the invention, the lens groups before and after the drive ring are held by the integrally formed main body cylinder, and the drive ring is arranged on the outer periphery of the main body cylinder. Since a holding frame for holding the front lens and a structure for attaching this holding frame to the main body cylinder are unnecessary,
The configuration can be simplified and the cost can be reduced. Moreover, since all the lenses are attached to one main body cylinder, there is also an advantage that the accuracy of the optical axis can be improved.

[0019]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a camera lens barrel according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a diaphragm driving unit in FIG. 1, and FIG.
2 is a sectional view taken along line II-II in FIG. 1, and FIG. 1B is a top view of the iris ring in FIG.

FIG. 3 is a perspective view showing a configuration of an iris ring according to an embodiment.

FIG. 4 is a diagram showing the configuration and operation of the diaphragm blade of the embodiment.

5A and 5B are views showing a second example of the connection structure of the iris ring and the connecting screw shown in the embodiment, where FIG. 5A is a top view and FIG.

6A and 6B are views showing a third example of the connection structure of the iris ring and the connecting screw, FIG. 6A is a top view, and FIG. 6B is a sectional view.

7A and 7B are views showing a fourth example of the connection structure of the iris ring and the connecting screw, FIG. 7A is a top view, and FIG. 7B is a sectional view.

FIG. 8 is a cross-sectional view showing a configuration of a conventional lens barrel for a camera.

[Explanation of symbols]

1, 12 ... Main body tube, 2 ... Rear lens group, 4 ... Front lens group, 7, ... Kikuza, 8, 14, 25, 29, 31 ... Iris ring, 9, 23 ... Engagement pin, 21 ... diaphragm blades, 27 ... engagement groove, 28 ... connecting screw, H ... Open end.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-127726 (JP, A) JP-A-54-26731 (JP, A) Actually open Hei 3-73904 (JP, U) Actually open 60- 107814 (JP, U) Actual development 58-26012 (JP, U) Actual development 61-104420 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 7/02-7 / 16 H04N 5/222-5/257

Claims (2)

(57) [Claims] 1. A main body for holding a lens is arranged on the outer periphery of the cylinder.
The thin plate is bent into a cylindrical shape and its mating end can be
It consists of a thin plate ring opened so that it can be changed
A drive ring for setting <br/> photographing condition attached to the main body tube periphery with an increasing serial combined open end, or both to form of the open end of the open end of the drive ring
The drive ring and a groove for engaging the U-shaped opening
A connecting screw for connecting the drive member inside the main body cylinder,
A lens barrel for cameras configured with . 2. The lens groups arranged before and after the drive ring position are held by an integrally formed main body cylinder, and the drive ring is fitted on the outer periphery of the main body cylinder. The lens barrel for a camera according to claim 1.