JPS6245964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zoom lens having a close-up shooting function, and in particular, to a zoom lens having a close-up shooting function, in particular, each shooting operation for zooming shooting and close-up shooting is operated by a single operating member, and the operating member moves straight in the optical axis direction. The present invention relates to a device that performs a switching operation between zooming photography and close-up photography by movement and rotational movement around an optical axis.

Camera lenses that allow close-up photography in addition to normal distance photography, and zoom-operated lenses that allow close-up photography have been known for a long time. Normally, the adjustment mechanism for distance shooting or zooming is separate from the adjustment mechanism for close-up shooting, and a complicated mechanical interlock system is used between them. The structure was complicated, the handling was difficult, and it was not easy to operate.

The present invention has been developed in view of this point, and allows three types of operations, namely zoom adjustment and adjustment to normal distance and close distance (so-called macro distance), to be easily performed using a single operating member. A further object of the present invention is to provide a switching device for sequentially performing zooming, distance adjustment, and close-up photography using a single operating member.

The conventionally known close distance adjustment mechanism using a single operating member rotates the operating member further than the normal range of rotation for distance shooting, and allows the user to adjust the distance from the focal length adjustment lens group, variable power lens group, and correction lens group. Due to the structure in which the close distance adjustment is performed by separating the entire lens system or a part of the relay lens group from the fixed lens barrel and performing the feeding operation, it is difficult to engage and close the lens group when adjusting the close distance. An engagement-release device is required for disengagement, which makes the structure of the lens barrel very complex, and from the manufacturer's perspective, there are a large number of component parts, which increases the number of processing steps to improve the dimensional accuracy of each part. Increased manufacturing costs due to an increase in assembly processes and management processes, an increase in the number of managed parts, etc. Increased management costs in terms of production management due to an increase in management slips due to the increase in parts, quality control and durability due to the large number of parts, etc. From the user's point of view, the large size and weight of the device caused dissatisfaction with portability and operability.

The present invention makes it possible to manufacture each part and assemble the lens barrel in a short period of time by making the structure of the lens barrel as simple as possible, and the switching to the above three operating systems can be performed continuously, resulting in rapid operation. It is an object of the present invention to provide a zoom lens barrel that does not miss a shutter chance and has excellent operability, particularly a zoom lens barrel equipped with a close-up photographing mechanism.

Embodiments of the present invention will be described in detail below with reference to the drawings. This embodiment shows an example of application to an interchangeable lens barrel of a single-lens reflex camera. Reference numeral 1 denotes a fixed barrel of a lens barrel, and a mount member 2 having a mount means for coupling with a mounting portion of a camera (not shown) on one end side is integrally fixed with a screw 2a. A part of the mount member 2 holds a relay lens group _L1 .

As shown in FIG. 4a, the fixed barrel 1 has a rectilinear groove 1a along the optical axis, a rotation groove 1b communicating with the rectilinear groove 1a and formed concentrically around the optical axis, and furthermore a rotating groove 1b, which will be described later. It has a curved groove 1c for controlling the movement of the correction system lens group _L4 in the optical axis direction. On the other end side of the fixed lens barrel 1, there is a second lens group L ₂ for focus adjustment.
A front lens barrel member 6 integrally coupled with a holding member 4 that holds the front lens barrel is screwed together at respective helicoid portions 1d and 6a. 2c is a screw for fixing the holding member 2b of the first lens group _L1 and the fixed barrel 1; Reference numeral 2d denotes a joint cylinder which is fixed to the fixed cylinder 2 with screws 2e and has a scale displayed thereon.

A variable magnification lens group is provided in the inner diameter part of the fixed lens barrel 1.
_L3 and correction lens group _L4 are movably arranged by lens holding members 8 and 10 shown in FIGS. 4b and 4c. Reference numeral 12 denotes an operating member of the present zoom lens, which is fitted to the fixed barrel 1 via a joint barrel 14 and a zoom barrel 16 to be described later, and is used to perform linear operation in the optical axis direction and rotational operation. The joint body 14 has a screw 14 at one end.
It is fixed to the operating member 12 at point a, and the other end has a threaded portion 14a. A portion of the operating member 12 has a rectilinear groove 12a on the inside along the optical axis, and a pin is implanted in the rectilinear groove 12a on the cylindrical portion of the front lens barrel member 6 extending toward the camera side. 6b is inserted, and by rotating the operating member 12, the lens barrel member 6 is rotated around the optical axis, and the helicoid 1d.
6a controls the extension of the second lens group _L2 and adjusts the focus. 16 is a zoom cylinder disposed between the joint cylinder 14 and the fixed cylinder 1;
a threaded portion 16 that is threadedly coupled to the threaded portion 14a of No. 4;
a, and a notch 16b as shown in FIG. 4d is formed at one end in the subject direction. The lens holding member 10 of the fourth lens group _L4 is fitted into the fixed barrel 1, and a pin 10b implanted in the outer circumferential direction is inserted into the curved groove 1c of the fixed barrel. The feeding movement in the optical axis direction is controlled. Reference numeral 18 denotes a holding member for the third lens group _L3 , and one end of the member 18 passes through the inclined groove 10a of the lens holding member 10 and the straight groove 1a of the fixed barrel 1, and is attached to the zoom barrel 16 with a screw 8b. The other end is fixed to the third lens holding member 8 with a screw 8a.
Fix it with. As shown in FIGS. 4b and 4d, the third lens holding member 18 is fixed with a screw 8b in a circumferential groove 16c formed in the zoom barrel 16, and
A fitting portion 18c that fits into the _straight groove 1a of
It has a fitting part 18d that fits into the fitting part 18d. The zoom barrel 16 and the joint barrel 14 are screwed together with screws 16a and 14a, and during focus adjustment, the zoom barrel 16 is restricted from rotating depending on the engagement relationship between the holding member 18 and the linear groove 1a of the fixed barrel. Therefore, the operating member 12 and the joint barrel 14 rotate around the optical axis. Operation member 12 and joint body 1
4 around the optical axis is regulated by a stopper 19 fixed to one end of the zoom barrel 16 and a stopper 20 implanted inside the joint barrel 14. In the embodiment of the present invention, a zoom cylinder 16 is arranged between the joint cylinder 14 and the fixed cylinder 1, and the zoom cylinder performs a zooming action by moving the operating member straight in the optical axis direction.
Close-up photography is performed by rotating the optical axis around the optical axis, and when zooming, the operating member 1
2 and the zoom barrel 16 are connected by screws 14a and 16 as described above.
16a, the zoom barrel 16 is held at the shortest focal length position (wide position) shown in FIG. 2 during close-up shooting operations, and the operating member 12 and the zoom barrel 16 rotate together. It has means for fixing the zoom barrel 16 to a fixed barrel along the optical axis of the fourth lens group. and,
Close-up photography is performed by displacing the operating member when it is moved to the close-up photography operation position (the position shown in FIG. 2). Switching between zoom photography and close-up photography is performed by switching between fixation and detachment of the zoom cylinder 16 to the operating member 12 and the fixed cylinder 1. Next, this switching means will be described. The switching means is composed of a spring member 22, a switching plate 24, etc., and the spring member 22 has one end fixed to one end side of the outer peripheral surface of the zoom barrel 16 with a screw 22a, and the other end is folded back and has a free end. 2
It has become 2b. The switching plate 24 is fixed to the fixed cylinder 1. The joint body 14 has a notch 1 into which the folded portion 22b at one end of the spring member 22 is inserted.
4a.

Reference numeral 26 denotes an aperture value setting member fitted to the fixed barrel 1, which transmits aperture setting information to a known aperture unit 30 via a signal transmission member 28. Since the aperture mechanism can use a known means, the following explanation will be omitted.

Next, operations and effects in the embodiments of the present invention will be described. FIGS. 1 and 2 show the arrangement of each component with the operating member located at the longest focal length position (Tele side) and the shortest focal length position (Wide side), respectively. When the operating member is pushed in the optical axis direction from the position shown in FIG. 1, the third lens for variable magnification is fixed to the zoom barrel 16 via the holding member 18, so as the operating member 12 moves, it is displaced in the optical axis direction. do. At this time, the holding member 10 of the fourth lens group _L4
The linear movement of the holding member 18 is given a rotational movement by the engagement between the inclined groove 10a and the holding member 18, and at the same time, the engagement relationship between the pin 10b and the curved groove 1c causes rotational movement along the curved groove 1c in the optical axis direction. Extension control is performed, and a correction action of the optical system is performed in conjunction with the zooming action of the third lens group _L3 . By operating the operating member 12 in a straight line in the optical axis direction, the third lens group
_L3 is integrally displaced in the optical axis direction with the operating member,
The fourth lens group _L4 is displaced in the optical axis direction according to the amount of displacement of the curved groove 1c. The first lens group _L1 and the second lens group _L2 maintain their fixed positions. Focusing is achieved by rotating the operating member 12 around the optical axis, and the rotational force is applied to the linear groove 1 of the operating member 12.
2a and the implanted pin 6b on the front lens barrel member 6, the information is transmitted to the front lens barrel member 6, and is transmitted to the second lens group L by the helicoid coupling 1d and 6a with the fixed barrel 1. ₂ feeding control is performed. The rotation of the operating member 12 during focusing is stopped by the aforementioned stoppers 19 and 20. When the operating member 12 is moved straight from the tele side in FIG. 1 to the wide side in FIG. 2 and then rotated, the optical system moves to the close-up shooting area.

That is, from the wide side shown in the second figure, the operating member 12
When rotated, the stoppers 19 and 20 come into contact with each other, and when the operating member 12 is further rotated in the same direction, the portion 18c of the holding member 18 fits into the rotation groove 1b of the fixed barrel 1, and the operating member 12 and the zoom barrel 16 are rotated. are connected and rotate as a unit around the optical axis. As the zoom barrel 16 rotates, the holding member 18 also rotates as shown in FIGS.
The lens group _L4 moves according to the curved groove 1c of the fixed barrel 1, and at the same time the second lens group _L2 moves in the optical axis direction, and each lens group is placed in the position shown in Fig. 3 to enter the close-up shooting state. . Next, the switching operation between the operating member 12 and the zoom barrel 16 during the close-up shooting operation will be described. When operating close-up photography from a wide position, the joint barrel 1
4 and the stoppers 19 and 20 of the zoom barrel 16 rotate the zoom barrel 16 in the close-up shooting direction, but when returning from the close-up shooting position (FIG. 3) to the wide position, the stoppers 19 and 20 move away from each other. , and the zoom cylinder 16 is left in the close-up position. Therefore, wide position (6th position)
The spring member 2 is fixed to the outer periphery of the zoom barrel 16 when operating from the position shown in FIG.
2 is a change plate fixed on the fixed cylinder 1.
plate) 24 while rotating, spring 2
The free end 22b of 2 fits into the switching part 14a of the joint body 14. Conversely, when returning from the close-up shooting position shown in FIG. 7 to the normal shooting position shown in FIG. When the part plate 12 is rotated, it rotates integrally. When the switch returns to the position shown in FIG. 6, the spring 22 is released from riding on the switching plate 24, and the connection between the zoom barrel 16 and the joint barrel 14 is also released.

As described above, the present invention allows a zooming operation, a focus adjustment operation, and a close-up shooting operation to be performed using a single operating member, and moreover, when switching to the close-up shooting operation, there is no need to perform a special switching operation. ,
In addition to making it possible to switch to close-up photography simply by continuously rotating the operating member, the cam for close-up photography is also used as a cam for zooming, making it possible to create a zoom lens capable of close-up photography with a simple configuration. This is what we provide.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a zoom lens barrel according to an embodiment of the present invention, showing a state in which the optical system is set at the longest focal length position by pressing the operation member 12 in the camera mounting direction. FIG. 2 is a cross-sectional view of the state in which the operating member 12 is pressed toward the subject along the optical axis and the optical system is placed at the shortest focal length position. FIG. 3 is a sectional view of a state in which the operating member 12 is rotated around the optical axis from the position shown in FIG. 2 to move the optical system to a close-up photography area. FIG. 4 is a perspective view of the main components of the zoom lens barrel shown in FIGS. 1 to 3, and FIG.
Figure b shows the lens holding member 8 of the third lens group _L3 , and Figure 4c shows the lens holding member 1 of the _fourth lens group L4.
0, Fig. 4 d shows the zoom cylinder 16, Fig. 4 e shows the joint cylinder 1
4. FIG. 4f shows the operating member 12, and FIG. 4g shows the front lens barrel member 6. 5 and 6 show the operating states of the holding members and connecting means of each lens group at each position of the operating member 12, and FIG.
The figure shows the longest focal length position, FIG. 6 shows the shortest focal length position, and FIG. 7 shows the close-up shooting position.

Claims (1)

[Claims] 1. A focus lens group for focus adjustment;
It has at least three groups, a variable power lens group and a correction lens group for zoom adjustment, and macro adjustment is performed by moving at least one of the variable power lens group or the correction lens group in the optical axis direction. It has a zoom lens optical system that allows the movement of only the focus lens group in the optical axis direction by rotating the operating member around the optical axis, and also controls the zooming by moving in the optical axis direction. In a zoom lens that controls the movement of a system lens group and a correction system lens group in the optical axis direction, the zoom lens is supported to be movable in the optical axis direction and around the optical axis with respect to a fixed barrel, and the zoom lens group or the correction system lens group is A holding barrel is provided for holding either one of the lens groups of the system, and the fixed barrel is provided with a rectilinear groove in the optical axis direction having an end portion that restricts the movement position of one zoom end of the operating member, and rotation of the holding barrel is provided. A guide pin-cam groove mechanism for moving the holding tube in the optical axis direction for zoom adjustment is provided between the holding tube and the fixed tube, and the mechanism follows the operating member in both directions along the optical axis. At the same time, a zoom barrel is provided that follows the rotation beyond one end position of the focus adjustment range in the direction around the optical axis, and the zoom barrel holds the other of the variable power lens group or the correction lens group. is fixed to
Further, a holding member is provided, the holding member having a first guide part inserted into the linear groove of the fixed cylinder and a second guide part inserted into a cam groove formed in the holding cylinder in a diagonal direction of the optical axis; , the end portion of the straight groove of the fixed barrel is provided with a substantially orthogonal groove in a direction around the optical axis for allowing the operating member to interlock with the zoom barrel at a predetermined angle when one end of the zoom is moved; Further, the guide pin-cam groove mechanism is provided with an extension part in the direction of one end of the zoom, and the holding cylinder is rotated by moving the operating member in the optical axis direction. and moving in the optical axis direction, the holding member moves in the optical axis direction, and zoom adjustment can be performed by moving both the zoom adjustment lens groups in the optical axis direction,
Further, by rotating the operation member at one end of the zoom beyond the focus adjustment range, at least the lens group held in the holding barrel of both lens groups is moved in the direction of the optical axis toward the other end of the zoom. A zoom lens capable of close-up photography that can be moved to perform macro adjustments.