JPS6048004B2 - Zoom lens barrel with selectable controls - Google Patents

Description

[Detailed description of the invention] The present invention relates to a zoom lens barrel.

The present invention relates to the structure of a lens barrel of a zoom lens, and particularly to a variable magnification lens system that performs a magnification changing operation by changing the magnification of a lens optical system.
The number of cylindrical members of the lens barrel of a zoom lens, which contributes to the movement control in the optical axis direction of the correction lens system that corrects various aberrations of the image, is reduced as much as possible, and the number of cylindrical members is the minimum necessary. The first step is to obtain a zoom lens barrel by
The purpose of Furthermore, a second object of the present invention is to provide a zoom lens barrel of a so-called single operation ring type in which focusing operation and zooming operation are performed by a single operation member. The object of the present invention is to obtain a lens barrel of a zoom lens which also has the function of having a plurality of operation members by using a configuration in which a cam member that contributes to the variable power and correction functions of an optical system is operated for zooming. A third object of the present invention is to directly use a portion of the cam member as a display area for distance scales, display numbers, index lines, depth scales, etc. of the zoom lens, so that the lens optical system can be operated as in the conventional manner. It is an object of the present invention to provide a lens barrel for a zoom lens, which eliminates the need for multi-layering by covering a display ring member in addition to the structure of the zoom lens, and which makes it possible to achieve the first object of reducing the number of lenses.

To achieve the above object, the present invention includes a cam member having a cam groove for controlling the movement of the lens optical system fitted to the outer periphery of the base barrel of a lens barrel, and an operating ring fitted to the outermost side of the base barrel. However, the above object can be achieved by providing an externally exposed part on the J cam member at least in the optical axis direction, and by configuring the exposed part of the cam member to be used also as a display scale part in a zoom lens. It is something to do.

In recent years, an automatic exposure control mechanism (AE mechanism)7 has been incorporated, and electronics technology has been incorporated to provide various warning functions ranging from exposure control to low-luminance warnings and high-luminance warnings, as well as piezoelectric sounding elements and light-emitting bodies to provide various warnings using audible signals and light-emitting signals. Single-lens reflex cameras with built-in devices are rapidly becoming popular as the number of purchasers expands due to lower prices resulting from improvements in production technology and the introduction of automation technology.

With the spread of single-lens reflex cameras, demand for zoom lenses has been expanding from standard lenses to zoom lenses in the field of interchangeable lenses. However, in conventional zoom lenses, the mechanism for moving multiple lens optical systems in the optical axis direction is constructed by stacking many cylindrical members, which has problems such as being heavy and having poor operability. . In addition to the above-mentioned problems, the display ring that displays the variable magnification distance, shooting distance, etc. during zooming is provided independently of the lens barrel configuration that contributes to the movement control of the lens optical system, Since the display ring is combined with the lens barrel structure, the structure becomes increasingly multi-layered, which increases the weight and impairs operability.
The present invention takes the above-mentioned problems into consideration and aims to achieve the above-mentioned object, and aims at simplifying the lens barrel structure by providing a cam barrel member with many functions.

1 to 3 show lens configurations in this field, that is, a conventional single operating ring system.

1 is a mount member that connects the camera by known means;
Reference numeral 3 denotes a bayonet member, and 4 an aperture setting ring. The aperture is set by known means via an interlocking member 23 which is rotatably held around the optical axis by a regulating member 21.

Reference numeral 22 denotes a base cylinder which is integrally connected to the mount member 1 with screws 2, and on the inner circumferential side there is an intermediate member into which the front group lens barrel 16 holding the front group lens I is screwed together with helicoid screws 7c and 16c. The tube 7 is fitted with a rear group lens barrel 20 that holds the rear group lens 5.

Reference numeral 10 denotes an operating ring that is connected to the front group lens barrel 16 with screws 15, and a rubber ring 12 is fitted around the outer periphery of the operating ring.

Reference numeral 9 denotes a three scale ring having photographing distance numbers, which is rotatably connected to the intermediate cylinder 7 by screws 7b and 9b with minute leads, and a straight groove 9a is provided in a part of the scale ring, which is connected to the operating ring. A key screw 11 implanted in 10 is inserted, and distance scale ring 9 rotates as operation ring 10 rotates.

A limiting member 414 is fixed to the distance scale ring 9 by a screw 13, and limits the rotation angle of the operating ring 10 by coming into contact with a protrusion 7a provided on the intermediate cylinder 7. A cam cylinder 18 is fitted into the base cylinder 22 so as to be rotatable around the optical axis by a regulating member 17, and a pin 8 implanted in the intermediate cylinder 7 is connected to the linear groove 22a of the base cylinder 22 and the lead groove 1.
8b, and as the intermediate cylinder 7 moves in the optical axis direction, the rotating force is transmitted to the young ram cylinder 18.

Further, a pin 19 implanted in the rear group lens barrel 20 is engaged with the linear groove 22b of the base barrel 22 and the cam groove 18a. 6 is base cylinder 2
2 with a screw 5, and has a focal length number and an index line.

) With the above configuration, the operational relationship when transitioning from the long focal length state shown in FIG. 1 to the short focal length state shown in FIG. 2 will be explained.

First, when the operating ring 10 is moved in the optical axis direction, the front lens barrel 16 moves integrally because it is connected with the screws 15.

Furthermore, the front lens barrel 16 and the intermediate barrel 7 are connected by helicoid screws 7c.
, 16a, the intermediate cylinder 7 also moves together. At this time, the intermediate cylinder 7 is connected to the pin 8 and the straight groove 22a.
Rotation around the optical axis is restricted due to the relationship with the object, so it moves straight. Further, the distance scale ring 9 is also screwed into the intermediate cylinder 7 by screws 7b and 9b, so that it moves integrally. Next, the cam cylinder 18 rotates around the optical axis due to the movement of the intermediate cylinder 7, which moves integrally with the operating ring 10, due to the relationship between the pin 8 and the lead groove 18b.

The pin 19 implanted in the rear group lens barrel 20 is in the straight groove 22b.
Since the rear lens barrel 20 is engaged with the cam groove 18a, the rotation of the cam barrel 18 moves the rear group lens barrel 20 in the optical axis direction, thereby performing a zooming action.

Next, when the operating ring 10 is rotated, the operating ring 10 and the front lens barrel 16 are connected with the screw 15 in both FIGS. 1 and 2. 16 also rotates integrally. Here, since the intermediate barrel 7 is restricted from rotating relative to the base barrel 22, only the front group lens barrel 16 is extended according to the leads of the helicoid screws 7c and 16a, and a focusing action is performed. The distance scale ring 9 rotates together with the operation ring 10 due to the engagement between the key screw 11 and the straight groove 9a, but the distance scale ring 9 rotates together with the operation ring 10 due to the engagement between the key screw 11 and the straight groove 9a.
Since they are screwed together, there is almost no movement in the optical axis direction. Next, a method for reading the scale will be explained.

First, the focal length by the zooming operation is read by matching the focal length number displayed on the scale ring 6 connected to the base tube 22 with screws 5 and the circumferential end of the distance scale ring 9. In the case of focusing, the correspondence between the reference index line on the scale ring 6 and the shooting distance number on the distance scale ring 9 is read.

As is clear from the above explanation, the conventional configuration only displays the focal length scale and shooting distance scale, and there is a scale member that has almost no other function, resulting in a large and heavy structure. This is extremely unreasonable as it will lead to an increase in costs and product prices.

The present invention takes these points into consideration, solves the drawbacks of the conventional system, and aims to achieve the above object.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In each figure of FIG. 4 and FIG. 5, 30 is a mount member fixed to the base barrel 34 of the zoom lens with a screw 31,
The lens and the camera are coupled by bayonet coupling between the camera side mount member and the lens side bayonet ring 32 which is fitted with a camera side mount member (for example, a bayonet mount ring) not shown and is screwed to the mount member 30. It will be done.

37 is a cam cylinder fitted into the base cylinder 34, which can rotate around the optical axis with respect to the base cylinder 34, and whose movement in the optical axis direction is restricted by the regulating member 4.
5.

Reference numeral 38 denotes an intermediate cylinder fitted inside the base cylinder 34, and the intermediate 38 is screwed into the operating ring 36 placed on the outside of the cam cylinder 37 through fine screw threads 36a and 38a of the lead. It is screwed into a lens holder 42 that holds the first lens optical system 1 by threaded portions 38b and 42b.

Reference numeral 49 denotes a lens holder for holding the second lens optical system (2), which holds a known aperture device consisting of aperture blades 28, an aperture operating member 29, an aperture presetting cam ring 48, and the like.

A pin 46 is set up on the lens holder 49, and the pin 49 passes through a straight groove 34b provided in the base barrel 34.
It fits into a cam groove 37b provided on the inner peripheral surface of the cam cylinder 37. A portion of the intermediate tube extends toward the rear of the lens, and a pin 35 is erected at the extended portion, and the pin 35 is connected to the base tube 34.
It passes through a straight groove 34a provided in the cam cylinder and fits into a cam groove 37a formed in the inner circumferential surface of the cam cylinder.

Reference numeral 33 denotes an aperture reset ring, which fits into a recess formed by the base tube 34 and the mount member 30 and can engage with an aperture preset cam ring 48 held rotatably around the optical axis by a regulating member 47. becomes.

Since the configuration and operation of the throttle devices 28, 29, and 48 are well known, the description thereof will be omitted hereafter.

A key member 43 is fixed to the operating ring 36 with a screw 44, and the key member 43 is engaged with a straight groove 42a formed on the outer peripheral surface of the lens holder 42, and the key member 43 is fixed to the operating ring 36 with a screw 44.
The rotation is transmitted to the lens holder 42.

The outer peripheral surface 37c of one end of the cam cylinder 37 is connected to the operating ring 36.
It is configured so that it can be exposed from between the lens barrel and the base barrel 34 and can be visually recognized from outside the lens barrel. The operation of the zoom lens with the above configuration will be described.

First, when performing a zooming operation, when the operation ring 36 is moved back and forth in a straight line in the optical axis direction, the intermediate cylinder 38 is moved in the straight direction because the operation ring 36 and the intermediate cylinder 38 are screwed together 36a and 38a. This force in the straight direction of the intermediate cylinder 38 causes the pin 35 standing from the intermediate cylinder 38 to
4a, rotation around the optical axis is restricted. Further, since the lens holder 42 of the first lens optical system 1 is helicoidally coupled to the intermediate cylinder 38 and the intermediate cylinder 38, the first lens optical system 1 moves in the optical axis direction in accordance with the amount of movement of the operating ring 36. By moving the intermediate cylinder 38 in the optical axis direction, the cam cylinder 37 is aligned with the linear groove 34a of the pin 35 and the cam groove 37.
Rotation around the optical axis is performed by the engagement action with a.

By rotating the cam cylinder 37 around the optical axis, the straight groove 34 of the pin 46 erected on the second lens holder 49
The movement of the second lens holder in the optical axis direction is controlled by the engagement relationship at the intersection of the cam grooves 37b and 37b. By controlling the movement of the operation ring 36 in the optical axis direction, the distance between the first lens optical system I and the second lens optical system (■) to the focal reference plane (point) on the camera side and the distance between the lens optical systems The spatial distance is controlled to change and a zooming effect is obtained.
When the operation ring 36 is rotated around the optical axis, the key part) material 43
and the relationship between the straight groove 42a and the first lens holder 42
The first lens holder 42 is extended in the optical axis direction due to the relationship between the helicoid coupling 38b and the helicoid coupling 38b and 42b of the intermediate cylinder 38, thereby obtaining a focusing effect.

41 and 38c are pin members fixed to the operating ring 36 and the intermediate cylinder 38, respectively, and constitute means for regulating the rotation of the operating ring 36.

During the focusing operation, the operation ring 36 and the intermediate cylinder 3
8 through minute lead screws 36a and 38a, movement of the operating ring 36 in the optical axis direction during focusing operation is suppressed to a small extent.

5a and 5b show the scale display of the lens barrel of FIG.・0.3・0
．． 4...10-1 is displayed, and on the exposed portion 37c between the operation ring 36 of the cam barrel 37 and the base barrel 34, numbers 28, 35, . . . representing the focal length are displayed. 85, a reference index line 37d, and depth index lines provided before and after the reference index line 37d are displayed.

An index line 34c is displayed on the base cylinder 2. On the aperture reset ring 33, aperture value numbers 2.8, 4, . . . 16 are displayed. In the zoom lens having the configuration shown in FIGS. 4 and 5 above, a part of the cam tube that adjusts the spatial distance between the plurality of lens optical systems 1 and The exposed portion 37
By displaying numbers and index lines for lens measurement on c, the configuration can be simplified by eliminating the need for a special display ring, etc., and the function of the cam cylinder can be combined with the movement control function of the lens optical system and the display function. By combining these two features, the configuration of the zoom lens barrel can be simplified.

FIG. 6 and the following are other embodiments of the present invention, showing different examples of zoom lens optical systems, and showing zoom lenses. By providing the cam cylinder that performs the focusing operation with the role of a zooming operation ring, in addition to the advantages of the single operation ring system of the above embodiment, the advantages of the so-called independent operation system in which focusing and zooming operations are performed using separate members can be obtained. This is an example of a combination of the two. The same parts as those in the previous embodiment are designated by the same reference numerals and will be described in detail with reference to FIG. 6. In this embodiment, the base cylinder 34, cam cylinder 37, intermediate cylinder 3
8. The configurations of the operating ring 36 and the first lens holder 42 are the same as in the previous embodiment, so description 4 will be omitted. 50 is the second
This is a lens holder that holds the lens optical system (■), and the pin 51 set on the holder 50 is inserted into the straight groove 34b of the base barrel 34.
A lens holder 54 that penetrates through the cam tube and fits into the intersection with a cam groove 37e provided in the cam tube is a lens holder that holds the third lens optical system.
A cam groove 37f that penetrates the straight groove 34b of No. 4 and is provided in the cam cylinder.
It is inserted at the intersection with

The lens holder 54 holds known aperture devices such as the aperture blades 2, the aperture operating member 29, and the aperture presetting cam ring 48 described in the previous embodiment. 52 is the fourth
This is a lens holder that holds the lens optical system ■, and the pin 53 set on the holder 52 is inserted into the straight groove 3 of the base barrel 34.
4b and is fitted into the intersection with the cam groove 37g provided in the cam cylinder.

Cam grooves 37a, 37e, 37f, 3 provided in the cam cylinder
7g, when the operation is performed from the long focal length end side of FIG. 6a to the short focal length end side shown in FIG. It is desirable to use a bottomed groove for reasons such as the use of the groove. In the lens of this embodiment, when the operation ring 36 is moved in the direction of the optical axis, the intermediate tube 38 is also moved together with the first lens holder 42.
moves, and the cam cylinder 37 rotates around the optical axis due to the engagement between the linear groove 34a of the pin 35 and the cam groove 37a.

The rotational movement of the cam cylinder 37 causes each cam groove 37e of the cam cylinder to open.
Each lens holder 50, 54, along 37f, 37g
52 is movement controlled. Each lens optical system 1, ■, ■ uses a lens optical system with a four-group configuration of a known zoom lens, and each cam groove 37e, 37f, 37g of the cam tube is provided so that each lens optical system can be moved to an appropriate position. . Focusing is performed by rotating the operating ring 36 to move the first lens holder 42 in the optical axis direction. As described above, the present invention includes fitting a cam member into the base barrel of a zoom lens, providing an exposed portion exposed to the outside of the zoom lens on the cam member, and displaying the numbers and scale of the lens on the exposed portion. Furthermore, the exposed portion can be used as an operating portion during a zooming operation, and a zoom lens can be obtained which has both a simplified lens barrel configuration and an operability selection function.

In particular, in the present invention, the cam member does not simply play the role of controlling the movement of the lens optical system, but also actively serves as a display section and/or an operation section. This makes it possible to provide a zoom lens that has a function that does not exist, that is, a selection function of the operating section during zooming operations. Furthermore, as an effect of the present invention, the selectivity of the zooming operation section can be improved.

That is, as can be understood from the embodiments, the zoom lens of the present invention can perform a zooming operation using dual-purpose operation members 36 and 39 that can perform both focusing and zooming operations, and the exposed portion of the cam member 37.

The zooming operation using the dual-purpose operating member is a straight-line operation along the optical axis, and the zooming operation using the exposed portion is a rotational operation around the optical axis, and the operating directions are different. For zooming operations that increase the change in magnification from low magnification to high magnification or from high magnification to low magnification, some people prefer straight operation, while others prefer rotational operation. According to the present invention, since the zooming operation can be selected between a straight operation and a rotational operation, it is possible to select according to each person's preference. Further, as shown in FIGS. 7A and 7B, a knurling or ring 37h may be fixed to the exposed portion of the cam member as an operating section.

[Brief explanation of the drawing]

Figures 1, 2, and 3 show conventional zoom lens barrels, and Figure 1 is an axial cross-sectional view at a long focal length;
FIG. 2 is an axial cross-sectional view at a short focal length, and FIG. 3 is a plan view showing the scale of the zoom lens. 4a to 5b show the first embodiment of the present invention, and FIG. 4a is an axis showing the arrangement of main parts in the lens barrel when zooming to the long focal length side. directional cross section,
FIG. 4b is an axial cross-sectional view when the zooming operation is performed toward the short focal length side. FIGS. 5a and 5b are plan views showing scales and the like of the zoom lens. FIGS. 6a to 7b show the second embodiment of the present invention.
Fig. 6a is an axial sectional view when zooming is performed toward the long focal length/point distance side, and Fig. 6b is an axial sectional view when the zooming operation is performed toward the short focal length side. . FIGS. 7a and 7b are plan views showing scales and the like of the zoom lens. 34... Base cylinder, 37... Cam cylinder, 38... Intermediate cylinder, 36... Operation ring,
42, 49, 50, 52, 54...Lens holder.

Claims (1)

[Scope of Claims] 1. A cam cylinder having a cam groove is fitted on the outside of a fixed cylinder having a guide groove, an intermediate cylinder is fitted on the inside of the fixed cylinder, and the guide groove and the intermediate cylinder are fitted on the inside of the fixed cylinder. A lens holder is provided with a pin that engages at the intersection of the cam grooves, an operating member is placed on the outside of the cam barrel, and a threaded portion of the operating member is fitted inside and outside the intermediate barrel, and a lens holder is fitted inside the intermediate barrel. forming threaded portions that are threadedly engaged with the threaded portions of the cam cylinder, so that the cam cylinder is exposed when the operating member is operated straight in a direction parallel to the optical axis;
An exposed part for displaying a scale such as an index line is provided on the exposed outer peripheral surface of the cam barrel, and zooming can be performed by selecting either a linear operation of the operating member or a rotational operation of the exposed part of the cam barrel. A zoom lens barrel having a selectable operating section.