JP2773507B2 - Zoom 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 zoom lens barrel having a variable focal length.

[0002]

2. Description of the Related Art FIG.
FIG. 6 is a longitudinal sectional view of a zoom lens barrel of a so-called one-ring type, which is performed by one operation ring, and FIG. 5 and 6, 41a, 41b,
Reference numerals 41c and 41d denote lenses of a photographing optical system, 41a is a focus lens, 41b is a zoom variable power lens, 41c.
Is a zoom correction lens, and 41d is a fixed lens.

Reference numeral 42 denotes an optical axis, and 43 denotes a fixed part of a zoom lens barrel holding a fixed lens 41d.
, A cam groove 43b for the zoom correction lens 41c, a screw part 43c, a groove part 43 for detecting a zoom signal.
e. Reference numeral 44 denotes a focus lens barrel having a screw portion 44a screwed with the screw portion 43c. Reference numeral 45 denotes a holding barrel of the zoom lens 41b, and reference numeral 46 denotes a holding barrel of the zoom correction lens 41c.
a.

Reference numeral 47 denotes an aperture unit, and 48 denotes a screw portion 48a.
And a screw member 49 screwed with a screw groove 48a and a cam groove 49a parallel to the optical axis 42.
b. 50 is an outer cylinder, 51 is a lens mount, 5
Reference numeral 2 denotes a roller for the zoom correction lens 41c implanted on the outer surface of the holding barrel 46, which is fitted in the cam groove 43b. Reference numeral 53 denotes a focus roller implanted on the outer surface of the focus lens barrel 46, which is fitted with the cam groove 49a. Reference numeral 54 denotes a roller for the zoom variable power lens 41b.
The roller portion 54 is implanted on the inner surface side of the
a is fitted in the cam groove 43a and the cam groove 46a. 55
Is a rubber ring covering the operation member 49, 56 is a lens control circuit connected to the aperture unit 47 by an electric signal line, and 57 is a lens contact point connected to the lens control circuit 56 by an electric signal line.

Reference numeral 58 denotes an electric circuit board for detecting a zoom signal which is connected to a lens control circuit by an electric signal line, 59 denotes a brush for detecting a zoom signal made of a metal having a spring property, 60 denotes a camera body unit, and 61 denotes a camera body unit. A reflecting mirror, 62 is a pentaprism, 63 is a camera control circuit, and 64 is a camera contact connected to the camera control circuit 63 by an electric signal line. Further, the camera contact 64 is in contact with the lens contact 57. Reference numeral 65 denotes an imaging surface, 66 denotes a finder, and 67 denotes a power supply connected to the camera control circuit 63 by an electric signal line.

Next, the operation of the zoom lens barrel will be described. First, the focus operation is performed by rotating the operation member 49 about the optical axis. When the operation member 49 rotates, the roller 53 implanted in the focus lens barrel 44 is fitted in the cam groove 49a, and
Since the lens 3 and the focus lens barrel 44 are screwed together, the focus lens 41a can move in the optical axis direction and perform focusing.

At this time, since the screw pitch of the screw portions 48a and 49b is much smaller than that of the screw portions 43c and 44a, the operating member 49 moves only slightly in the optical axis direction.

The zoom operation is performed by moving the operation member 49 in the direction of the optical axis 42. When the operation member 49 moves straight in the optical axis direction, the rectilinear barrel 48 moves in the optical axis direction together with the operation member 49. The holding lens barrel 45 of the zoom variable power lens 41b is held by a roller 54 implanted in a rectilinear barrel 48, and the roller 54 is fitted into a cam groove 43a parallel to the optical axis 42 of the fixed portion 43. Zoom variable power lens 41
b moves in the optical axis direction together with the operation member 49.

At the same time, the cam groove 46a having the lead of the holding barrel 46 of the zoom correction lens 41c is engaged with the roller 54, and the roller 52 implanted in the holding barrel 46 is the cam groove of the fixed part 43. When the roller 54 moves in the optical axis direction because it is fitted to the 43b, the zoom correction lens 41c moves in the optical axis direction while rotating. In this case, the cam groove 4
Reference numeral 3b is provided so that the zoom correction lens 41c is located at an appropriate position in accordance with the position of the zoom variable power lens 41b. That is, when the operation member 49 is moved in the optical axis direction, the zoom variable power lens 41b and the zoom correction lens 41c are moved in the optical axis direction to perform a zoom operation. At this time, the focus lens 41a does not move in the optical axis direction.

Hereinafter, the detection of the zoom signal during the above-mentioned zoom operation will be described. As shown in FIG. 6, an electric board 58 is attached to the groove 43 e of the fixing portion 43, and the straight moving cylinder 48 to which the brush 59 is attached is
Is fixed to the fixing portion 43 so that the pattern of the fork portion and the pattern of the electric board 58 coincide with each other.

Since the rectilinear barrel 48 moves only in the optical axis direction by the zoom operation, the brush 59 moves on the pattern of the electric board 58. Further, since the rectilinear barrel 48 is coupled to the holding barrel 45 of the zoom lens 41b via the roller 54, the amount of movement of the rectilinear barrel 48 by the zoom operation is equal to the amount of movement of the zoom lens 41b.

Since the focal length of the photographing optical system can be determined by the position of the zoom lens 41b, a pattern corresponding to the amount of movement of the zoom lens 41b is used.
8, the zoom position can be detected.

In this conventional example, the entire zoom range is divided into four. Then, the lens control circuit 56 detects where on the pattern of the electric board 58 the brush 59 is located. This detection information is transmitted to the camera control circuit 63 via the lens contact 57 and the camera contact 64, and the camera control circuit 63 controls the camera at each zoom position.

[0014]

However, in the above conventional example, the movement of the rectilinear barrel in the optical axis direction is directly detected by the brush attached to the rectilinear barrel and the pattern of the electric board. On the other hand, when the amount of movement of the zoom variable power lens is large, there is a problem that the zoom signal cannot be detected.

Further, in a zoom lens barrel in which the rectilinear barrel rotates during a macro shooting operation or the like, the rectilinear barrel rotates during a macro operation or the like, causing a problem that a brush is destroyed or a zoom signal cannot be detected. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can perform a zoom operation and a focus operation with the same operation member, and can reliably detect a zoom signal and a macro signal. It is intended to obtain a zoom lens barrel.

[0017]

SUMMARY OF THE INVENTION The present invention is a zoom lens barrel having the following configuration. (1) An operation member capable of performing a zoom operation and a focus operation, and a zoom lens barrel having a zoom moving lens holding barrel that moves in the optical axis direction while rotating about the optical axis in accordance with the zoom operation, By providing a rotating member that engages with the zoom moving lens holding barrel and rotates about the optical axis at a fixed position in the optical axis direction, a zoom signal and a macro signal can be reliably obtained in a one-ring type zoom lens barrel. Can be detected. (2) It is characterized by having a position detecting means for the rotating member.

[0018]

【Example】

First Embodiment FIGS. 1 to 4 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a zoom lens barrel that best illustrates the features of the present invention, and FIG. FIG. 3 is a perspective view of a zoom signal detecting unit of the zoom lens barrel, and FIG.

1 to 4, 1a, 1b, 1
Reference numerals c and 1d denote lenses of a photographing optical system, 1a is a focus lens, 1b is a zoom variable power lens, 1c is a zoom correction lens, and 1d is a fixed lens.

Reference numeral 2 denotes an optical axis, and reference numeral 3 denotes a fixed portion of a zoom lens barrel holding a fixed lens 1d. As shown in FIGS. 1 and 2, a cam groove 3a parallel to the optical axis 2 and a zoom correction lens are provided. It has a cam groove 3b for 1c and a screw portion 3c. Reference numeral 4 denotes a focus lens barrel, and a screw portion 4a screwed with the screw portion 3c.
Having. Reference numeral 5 denotes a holding barrel of the zoom lens 1b as a zoom moving lens holding member, and reference numeral 6 denotes a holding barrel of a zoom correction lens 1c as a zoom moving lens holding member, which has a cam groove 6a having a lead and a hole 6b. . Reference numeral 7 denotes an aperture unit, and reference numeral 8 denotes a rectilinear cylinder, which has a screw portion 8a as shown in FIGS. Reference numeral 9 denotes an operation member, which includes a cam groove 9a parallel to the optical axis 2 and a screw portion 9 screwed with the screw portion 8a.
b. 10 is an outer cylinder, 11 is a lens mount, 1
Reference numeral 2 denotes a roller for the zoom correction lens 1c implanted in the holding barrel 6, reference numeral 13 denotes a focusing roller implanted in the focus lens barrel 4, reference numeral 14 denotes a roller for the zoom lens 1b, and cam grooves 3a. Roller portion 14a engaging with cam groove 6a
And is implanted on the inner surface side of the rectilinear barrel 8.

Reference numeral 15 denotes a rubber ring covering the operation member 9, and reference numeral 16 denotes a lens control circuit, which is connected to the diaphragm unit 7 by an electric signal line. Reference numeral 17 denotes a lens contact, which is connected to the lens control circuit 16 by an electric signal line. Numeral 18 denotes an electric board for zoom signal detection attached to the fixed part 3 as shown in FIG.
a, 18b, and 18c, and are connected to the lens control circuit 16 by electric signal lines.

Reference numeral 19 denotes a rotatable member rotatably held by the fixed portion 3, which has an arm 19a and an arm 19b which engage with the hole 6b of the holding lens barrel 6. As shown in FIG. 3, a brush 20 whose tip is in contact with the electric board 18 is held by the arm 19 b of the rotating member 19.

21 is a screw for fixing the roller 12 to the holding barrel 6, 22 is a screw for fixing the roller 14 to the rectilinear barrel 8, 30 is a camera body unit, 31 is a reflecting mirror, 32 is a pentaprism, 33 is a camera control circuit, 3
Reference numeral 4 denotes a camera contact connected to the camera control circuit 33 by an electric signal line.
Is in contact with 35 is an imaging surface, 36 is a viewfinder,
Reference numeral 37 denotes a power supply connected to the camera control circuit 33 by an electric signal line.

Next, the operation of the zoom lens barrel in the first embodiment will be described. First, a focus operation is performed by rotating the operation member 9 about the optical axis. When the operation member 9 rotates, the focus lens barrel 4
Is engaged with the cam groove 9a, and the fixed portion 3 and the focus lens barrel 4 are screwed together.
The focus lens 1a can move in the optical axis direction to perform focusing. At this time, the screw portions 8a, 9
Since the thread pitch of b is much smaller than that of the thread portions 3c and 4a, the operating member 9 moves only slightly in the optical axis direction.

In the case of a zoom operation, the operating member 9 is
By moving in the direction of. When the operating member 9 moves straight in the optical axis direction, the rectilinear barrel 8 moves in the optical axis direction together with the operating member 9. The holding lens barrel 5 of the zoom variable power lens 1b is held by rollers 14 implanted in the rectilinear barrel 8, and the roller portions 14a are engaged with the cam grooves 3a of the fixed portion 3 parallel to the optical axis 2. The zoom variable power lens 1b moves in the optical axis direction together with the operation member 9.

At the same time, the cam groove 6a having the lead of the holding barrel 6 of the zoom correction lens 1c is
a, and the roller 12 implanted in the holding barrel 6 is engaged with the cam groove 3b of the fixed portion 3, so that when the roller 14 moves in the optical axis direction, the zoom correction lens 1c It moves in the optical axis direction while rotating. In this case, the cam groove 3b
Is provided so that the zoom correction lens 1c is at an appropriate position according to the position of the zoom variable power lens 1b. That is, when the operation member 9 is moved in the optical axis direction, the zoom variable power lens 1b and the zoom correction lens 1c are moved in the optical axis direction to perform a zoom operation. At this time, the focus lens 1a does not move in the optical axis direction.

Next, detection of a zoom signal during the zoom operation will be described. As shown in FIG. 3, the electric board 18 is attached to the fixing part 3, and the tip of the brush 20 held by the arm 19 b of the rotatable member 19 held rotatably contacts the electric board 18. I have. The arm 19a of the rotating member 19 is engaged with the hole 6b of the holding barrel 6, and the rotating member 19 rotates according to the rotation of the holding barrel 6.

The electric board 18 has conductive patterns 18a, 18b, 18c as shown in FIG. 3, and when the contact position with the brush 20 changes, the patterns 18a and 18b, and the patterns 18a and 18c Changes, and it is possible to detect where the brush 20 is on the pattern. The detection of the position of the brush with respect to the electric board is known.

That is, when the zoom operation is performed as described above, the holding lens barrel 6 moves in the optical axis direction while rotating.
The rotating member 19 also rotates according to the rotation of the holding barrel 6,
The position of the brush 20 with respect to the electric board 18 changes. Then, the patterns 18a, 18b, 18c of the electric board 18 are formed.
By detecting the position of the brush 20 from the conduction state of
The lens control circuit 16 detects which region the focal length of the photographing optical system is in. This detection information is used as the lens contact point 17,
The information is transmitted to the camera control circuit 33 via the camera contact 34, and control according to each zoom region is performed by the camera control circuit.

Macro photography can also be performed using the zoom lens barrel of this embodiment. In the case of a macro operation, the operation member 9 is moved to the object side most (in this embodiment, at the wide-angle end),
Further, the operation is performed by further rotating the operation member 9 from the state where the focus lens 1a is extended most.
The cam groove 3a of the fixed portion 3 has a shape as shown in FIG. 4, and the roller 14 can rotate about the optical axis 2 only at the wide-angle end.

That is, when the operating member 9 is further rotated while the focus lens 1a is extended most at the wide-angle end, the rectilinear barrel 8 rotates. Then, the zoom variable power lens 1b does not move in the optical axis direction, but the holding lens barrel 6 rotates about the optical axis, and at the same time, moves in the optical axis direction due to the relationship between the cam groove 3b and the cam groove 6a, thereby performing a macro operation. .

However, the cam groove 3a is arranged such that the macro area intrusion direction coincides with the rotation direction of the rectilinear barrel 8 and the rotation direction of the operating member 9 for extending the focus lens 1a.
Is composed. In addition, the straight moving cylinder 8 can be
Is configured not to rotate during a focus operation. Although this configuration is publicly known, in the case of a zoom lens barrel capable of performing such a macro operation, only a macro signal can be detected as described above.

When the operation member 9 is moved in the zoom end direction where the macro operation can be performed (in this embodiment, the operation member moves from the telephoto to the wide-angle direction), the rotation direction of the holding barrel 6 and the operation member 9 are moved. When the rotation direction of the holding lens barrel 6 when operating in the macro penetration direction matches (for example, when the zoom correction lens 1c has a positive power in the present embodiment).
By knowing the amount of rotation of the rotating member 19 described above, both the macro signal and the zoom signal can be similarly detected.

In this embodiment, the rotation position of the rotating member 19 is detected by the pattern of the brush and the electric board. However, the rotation position of the rotating member 19 may be detected by any encoder. Further, the engagement between the holding barrel 6 and the rotating member 19 may be performed by a structure in which an arm is provided on the holding barrel 6 and a hole or a groove for engaging with the arm is provided in the rotating member 19. .

[0035]

As described above, according to the present invention, there is provided a rotating member which engages with the zoom movable lens holding barrel which moves in the optical axis direction while rotating and rotates at a fixed position in the optical axis direction.
Since the detection means for detecting the rotational position of the rotating member is provided, in a zoom lens barrel in which the moving amount of the zoom variable lens is large with respect to the entire length of the zoom lens barrel, or in which the rectilinear barrel rotates during macro shooting, There is an effect that the zoom signal and the macro signal can be detected reliably.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a zoom lens barrel showing a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part in the first embodiment.

FIG. 3 is a perspective view of a zoom signal detection unit according to the first embodiment.

FIG. 4 is a perspective view of a fixing portion provided with a cam groove for performing a macro operation.

FIG. 5 is a longitudinal sectional view of a conventional one-ring type zoom lens barrel.

FIG. 6 is a perspective view of a main part of a conventional zoom lens barrel.

[Explanation of symbols]

2 Optical axis 3 Fixed part 4 Focus lens barrel 5 Holding zoom lens barrel (zoom moving lens barrel) 6 Zoom zoom lens holding lens barrel (zoom moving lens barrel) 9 Operating member 18 Electrical board 18a -18c signal pattern (position detecting means) 19 rotating member 20 brush (position detecting means)

Claims (2)

(57) [Claims] 1. A zoom lens barrel having an operation member capable of performing a zoom operation and a focus operation, and a zoom movable lens holding barrel that moves in the optical axis direction while rotating about an optical axis in accordance with the zoom operation. 2. The zoom lens barrel according to claim 1, further comprising a rotating member that engages with the zoom movable lens holding barrel and rotates about the optical axis at a fixed position in the optical axis direction. 2. The zoom lens barrel according to claim 1, further comprising a position detecting unit for the rotating member.