JPH04305606A - Zoom range varying device for zoom lens barrel - Google Patents

Abstract

PURPOSE:To offer a zoom range varying device which can vary a zooming range without altering the internal structure of the zoom lens barrel at all. CONSTITUTION:This device is provided with an arcuate frame 8 (base hardware) fitted to the outer peripheral surface of the lens barrel, a stopper fitting member 10 fitted to the frame 8 so that the fixation position can be changed in the circumferential direction, a stopper 6 fitted to the stopper fitting member 10, and a lock knob 7 which fixes the stopper 6 to the member 10. The stopper 6 is rotatable on the radial axis of the lens barrel and advances/retracts to/from the movement path of a zoom pin 4. The stopper fitting member 10 can be changed in its fixation position along the groove 9 of the frame 8, so the stopper 6 can be changed in position.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom range variable device for use in a manually operated zoom lens barrel.

0002

2. Description of the Related Art In recent years, there has been an increase in the number of opportunities for outdoor photography with handy lenses, and there is a growing demand for higher magnification as well as lighter weight for more mobile operation. However, in zoom lenses, the open aperture F-number must be kept constant over the entire zooming range, but in high-power zoom lenses, designs that balance optical performance with the aim of being lightweight and compact are required. Therefore, as shown in FIG. 8, on the telephoto side above a certain zoom level, the open F value increases and the subject image may become dark.

[0003] Therefore, a zoom lens equipped with a mechanism to limit the zooming range so that the zoom operation is performed only within the range where the F value of the high-power zoom lens is constant is disclosed in, for example, Japanese Patent Laid-Open No. 53
This method has been proposed in Japanese Patent Publication No. 48732 and Japanese Patent Application Laid-Open No. 57-51364.

0004

[Problems to be Solved by the Invention] However, in the conventional example described above, the lens body is provided with a complicated mechanism for limiting the zooming range, which increases the weight of the lens body, and also requires manual focusing and zooming. There is a problem that the above-mentioned device obstructs the operation and prevents smooth operation, and that the handy lens loses its maneuverability.

An object of the present invention is to provide a zoom range variable device that can freely set the zoom range of a manual zoom lens barrel without changing the design or internal structure of the main body of the lens barrel. The goal is to provide the following.

[0006]

[Means for Solving the Problems] In the present invention, a zoom range variable device is constructed that uses a zoom pin used in a zooming operation of a handy lens to limit the zooming operation range outside the lens body.

[0007]

[Operation] Since the zoom range variable device of the present invention only needs to be attached to the outer peripheral surface of the zoom lens barrel, there is no need to change the design of the internal structure of the lens barrel, and it can be applied to all zoom lens barrels. Can be done.

[0008]

[Examples] The present invention will be explained in more detail with reference to Examples below. FIG. 1 shows a state in which a zoom range variable device according to a first embodiment of the present invention is attached to an ordinary handy lens 1.

In FIG. 1, 1 is a handy lens, 2 is a focus ring for performing focusing operations, 3 is a zoom ring for zooming operations, 4 is a zoom pin,
It is. Since the zoom pin 4 is interlocked with the zoom ring 3, a zooming operation using the zoom pin 4 is also possible. 5 is an iris ring for controlling the iris. 1, 2, and 4, the zoom pin 4 is in a state where its zoom range is restricted by the variable stopper 6 on the TELE side. 7 is a lock knob for fixing the variable stopper 6. The lock knob 7 is rotatable in the circumferential direction by a guide groove 9 provided in the base hardware 8, so the stopper mounting hardware can change the fixing position in the circumferential direction with respect to the lock knob 7 and the base hardware 8. Since the variable stopper 6 is also rotatable in the circumferential direction via the zoom pin 10, the rotation range of the zoom pin 4 can be regulated variably. Since the arc-shaped base hardware 8 is fixed to various lenses using existing and common mounting holes,
It can be installed on conventional lenses without any modification.

Note that FIG. 2 is a cross-sectional view along line AA in FIG. 1, FIG. 3 is a view from B in FIG. 2, and FIG. 4 is a view from C in FIG. From these figures, it will be understood that the rotation of the zoom pin 4 is regulated by the variable stopper 6.

Further, referring to FIGS. 4 and 5, it will be understood that the position of the variable stopper 6 can be varied by the guide groove 9, and that the regulation of the rotation range of the zoom pin 4 can be varied.

Further, as shown in FIG. 6, the variable stopper 6 is rotatable around a pin 11 provided on the stopper mounting hardware 10, and therefore the stopper 6 can be easily stored in the base hardware 8. , zooming restrictions can be easily canceled.

Note that in this embodiment, the variable stopper 6
Since it is rotatable around the pin 11, it can be stored in the base hardware 8, but it may be of a sliding type as in the embodiment shown in FIG. In addition, variable stopper 6
may be fixed using screws.

Furthermore, if the variable stopper 6 is provided on the wide side as shown by the two-dot chain line in FIG. 2, it becomes possible to limit the zooming range on the wide side.

Furthermore, by combining the two embodiments described above, it is possible to simultaneously limit the zooming range on the telephoto and wide side.

[0016]

Effects of the Invention As explained above, the device of the present invention is attached to the outside of an existing zoom lens barrel to limit the operating range of the zoom pin. Since there is no need to provide a limiting mechanism, there is no need to complicate the mechanism of the zoom lens barrel, increase the weight, or increase costs.

[Brief explanation of drawings]

FIG. 1 is an external view of a manually operated zoom lens barrel equipped with a variable zoom range device of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a view from B in FIG. 2;

FIG. 4 is a view from C in FIG. 2;

5 is a diagram showing a state in which the stop limit position of the zoom pin 4 is changed by changing the fixing position of the stopper 6 in the configuration shown in FIG. 2. FIG.

6 is a diagram showing a state in which the stopper 6 is retracted from the movement path of the zoom pin 4 in the configuration shown in FIG. 2. FIG.

FIG. 7 is a diagram showing another embodiment of the structure in which the stopper 6 is not rotatably attached to the base metal fitting 8 but is linearly movable.

FIG. 8 is a diagram showing the relationship between the open aperture F value and the focal length f of a zoom lens.

[Explanation of symbols]

1: Handy lens
2: Focus ring 3: Zoom ring
4: Zoom pin 5: Iris ring
6: Variable stopper 7: Lock knob
8: Base hardware (frame) 9: Guide groove
10: Stopper mounting hardware 11: Pin

Claims (1)

[Scope of Claims] [Claim 1] An arc-shaped frame that is detachably attached to the outer peripheral surface of a manual zoom lens barrel and extends along the movable range of a zoom operation pin of the lens barrel. , a stopper mounting member fixedly and variablely attached to the frame along the longitudinal direction of the frame, that is, along the circumferential direction of the lens barrel; and a stopper mounting member rotatable about the radial axis of the lens barrel. a stopper that is attached to the stopper mounting member and moves in and out of the movement path of the zoom operation pin; and a stopper that is attached to the frame so that the fixing position can be changed along the circumferential direction of the lens barrel; and a stopper fixing member attached to the stopper attaching member.