JPS638885Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a lens barrel for a photographic lens for a camera, which allows the lens to be driven by manual operation and by a motor.
Drives the lens for zooming and focus adjustment,
The present invention relates to a photographic lens barrel configured to be driven both manually and electrically by a motor.

BACKGROUND ART As a lens of this type, a photographing lens is known in which, for example, a distance ring for focus adjustment can be manually operated and can also be moved electrically by the output of a motor. With this type of lens, if you touch the distance ring while it is being driven by the motor, it may put an excessive load on the motor or slow down the focusing lens. There is an inconvenience that focusing operations are time-consuming and slow.

Therefore, in order to eliminate such inconveniences, the following devices have been proposed.

1. An eave-like protective wall is fixed on the fixed part of the outer periphery of the lens barrel, and this protective wall completely covers the lower half of the distance ring to prevent at least the hand holding the camera from touching the distance ring. A structure designed to prevent this (Japanese Patent Application Laid-Open No. 57-30809).

2 The photographing lens is built into the camera body so that only a part of the range ring is exposed through a window cut into the camera body, and a shielding member is provided inside the camera body so that when the lens is driven by a motor, this shielding member is installed. A configuration in which the window is closed with a shielding member (USP4153903).

However, when these devices are driven by a motor, the operation ring (for example, the distance ring)
Too much attention is paid to whether to cover the
The configuration is such that only a small portion of the operating ring is exposed during manual operation. Therefore,
During manual operation, the direction in which you can extend your finger to operate the control ring is limited, and you may not be able to rotate it while holding the control ring. Since it has to be changed depending on the position (attitude for positional photography and attitude for horizontal photography), it has the drawback that its operability and speed are greatly hindered.

Purpose This invention was made in order to eliminate the drawbacks of the above-mentioned prior art, and its purpose is to:
For photographic lenses that can be driven both manually and by a motor, it is possible to block the photographer's hand from accidentally touching the operating ring when the motor is driving the lens, and also to prevent the operator's hand from accidentally touching the operating ring. It is an object of the present invention to provide the above-mentioned lens, in which the operation ring can be operated from any direction during operation, and a focusing operation can be performed quickly.

Embodiment Figures 1 and 2 show an embodiment of this invention. An example of the interchangeable lens used is shown. This lens is a so-called internal focus type lens.
1st, 2nd and 4th group lenses (,,)
remains fixed, and the third lens group ()
Focus adjustment is performed by moving the chisel back and forth on the optical axis.

In the figure, 1 is a mount member which is detachable from a camera (not shown), 2 is a fixed tube fixed to the mount member 1, and 3 is a lens holding tube, which is fixed to the fixed tube 2. That is, the rotation of these three members around the optical axis 0 and the back and forth movement along the optical axis 0 are mutually restricted, and they remain stationary at the positions shown in the figure. The lens holding cylinder 3 is provided with a cam groove 3a, and a pin 4a installed in the movable lens frame 4 that holds the third lens group passes through the cam groove 3a. Reference numeral 5 denotes a distance ring rotatably fitted into the lens holding tube 3, and this distance ring is provided with a rectilinear groove 5a parallel to the optical axis 0, and a pin 4a passing through the cam groove is inserted into the distance ring. It fits into this groove 5a. 6
is a rubber ring whose outer circumferential surface is provided with uneven portions for anti-slip purposes, and is attached to the distance ring 5. 7 is a retaining ring for preventing the distance ring 5 from coming off. A rotating ring 9 is fixed to the rear end (mount side) of the distance ring 5 via an adhesive tape 8. A gear portion 9a is integrally formed on the rear inner circumferential surface of the rotating ring 9, and a gear 10 meshes with this gear portion 9a.

The gear 10 is fixed to a driven shaft 11, and both ends of the driven shaft 11 are rotatably supported by a bearing member 12 fixed to the wall of the mount member 1 and the front part of the fixed cylinder 2, respectively. has been done. An engaging portion 11a is formed at the rear end of the driven shaft 11, and when the lens body is attached to the camera, this engaging portion engages with a driving member protruding from the camera side to engage the engaging clutch. It has a similar shape and serves to connect the driven shaft to the motor built into the camera.

Further, a cavity for housing a switch mechanism is formed in the front part of the fixed cylinder 2, and a detection pin 13 and a switch 14 are housed inside the cavity.
The detection pin 13 is fitted into a cylindrical part formed at the tip of the screw 15, and is held so as to be movable in a direction parallel to the optical axis. , is biased so as to protrude to the left in the figure. Although the switch 14 is shown below the detection pin 13 for convenience of explanation, it is actually fixed to the side wall forming the cavity. The movable piece of this switch 14 faces within the movement locus of the detection pin, and is formed so that when the detection pin 13 is pushed in against the spring, it is pushed and comes into contact with the fixed contact piece (switch-on). There is. Each contact piece of the switch 14 is connected to a contact point 1 provided on the rear end surface of the mount member 1 via a conductive wire.
a and 1b, and when this contact comes into contact with a contact (not shown) provided on the camera side when the lens is attached, the autofocus circuit including the built-in motor drive circuit on the camera side is activated. It is starting to form.

Reference numeral 16 denotes a protective tube, which is movable at least in the direction of the optical axis, and has two positions: one in which it completely covers the distance ring 5 (Fig. 1), and the other in which the distance ring is completely exposed (Fig. 2). It is formed so that it can be moved between two positions. Numeral 17 is a hood for preventing harmful light from entering, and like the protective tube, it is movable in the optical axis direction, and has two positions: a retracted position (Fig. 1) and a hood use position protruding toward the subject (second position). The structure is such that it can be moved between the two positions shown in the figure. Both of these members have C-shaped click springs 18, 1.
9 are provided, and these springs are configured to engage with concave portions 3b and 3c provided in the lens holding cylinder 3, thereby allowing both members to be lightly locked in a predetermined position. 20, 21, 22 are
A cushioning member made of flexible materials such as rubber or cloth.
This is to prevent scratches from being formed on the fixed tube when the protective tube 16 and hood 17 move. Reference numeral 23 denotes a rubber ring having irregularities formed on its outer peripheral surface to prevent slipping.

Next, the operation of the above configuration will be explained.
In the following, for convenience, the lens shown in the drawings will be described in a state where it is attached to the camera body. Therefore, the driven shaft 11 is connected to the camera's built-in motor via its engagement portion 11a, and the switch 14 is connected to the camera's autofocus including the motor drive circuit via contacts 1a and 1b. It is connected to the cass circuit and is in a state where it can function as a circuit switch.

In FIG. 1, the protective tube 16 has been moved to a position that completely covers the distance ring 5, so the detection pin 1
3 is pushed in by the rear end face of this protection cylinder to turn on the switch 14. Therefore, when an operation for autofocusing is performed on the camera side, for example, when the shutter button is pressed halfway, power is connected to the autofocus circuit and the motor rotates. When the motor on the camera side rotates, the rotation is transmitted to the driven shaft 11 via the engaging portion 11a, and further transmitted to the rotating ring 9 via the gear 10 integrated with this driven shaft. And the distance ring 5 integrated therewith begins to rotate. When the distance ring 5 rotates, the pin 4 fits into the straight groove 5a provided in the distance ring.
Since the lens a moves guided by a cam groove 3a formed in the lens holding cylinder, the third lens group connected to this pin 4a moves back and forth on the optical axis.

As described above, while autofocusing is being performed, the distance ring 5 is rotated by the drive of the motor on the camera side, but there is no chance that the photographer's finger will come into contact with the distance ring 5 during this operation. However, such movement of the finger is completely blocked by the protection tube 16. That is, as mentioned above, since the protective tube 16 is located outside the distance ring 5 so as to cover it, a finger attempting to approach the distance ring 5 is blocked by the protective tube 16 and cannot be reached by the distance ring. cannot be reached. Therefore, during autofocusing operation, the distance ring 5 can be rotated easily without any negative effects caused by finger contact, and the photographer can safely and securely hold the camera without any worries. Can be dewinged. In addition, when you want to use the hood 17,
Of course, it is sufficient to pull the hood 17 forward and move it to the position shown in the second figure.

Next, when manual focusing operation is to be performed, the protective tube 16 is first moved to the tip side of the lens body (to the left in the figure) and set at the position shown in FIG. 2. As a result of the protection tube 16 being moved in this way, the distance ring 5 is completely covered, as shown in the figure, both in the width direction of the distance ring (direction parallel to the optical axis) and in its circumferential direction. exposed without being exposed. As a result of removing the cover in the circumferential direction of the distance ring, the photographer can rotate the distance ring by holding out his/her finger from any direction, and the rotation of the distance ring is performed as described above. This causes movement of the three lens groups in the optical axis direction. After adjusting the focus using these operations, you can take a photo by pressing the shutter button. At this time, when you press the shutter button halfway, the camera's
The switch for starting autofocus is closed, but since the switch 14 on the lens side has already been opened, there is no possibility that the autofocus circuit will operate. That is, as described above, by moving the protective tube 16, the detection pin 13 is released from the pressure by the protective tube and returns to the left, opening the switch 14. From now on, the shutter button on the camera side is pressed. Even if is pressed, the autofocus circuit remains off and does not operate.

In the above embodiment, as is clear from the figure, the position of the hood 17 when it is in the retracted position and the position of the protection tube when the protection tube 16 is moved to the left are approximately the same position, in other words. Then, since both parts are arranged so that the movement trajectory of the hood overlaps with the movement path of the protection tube, the space required for moving both parts can be shared, and the overall length of the lens barrel can be made compact. be.

In addition, in the case of this embodiment, the protection tube 16 and the hood 1
7 are formed from separate members, but they may be formed from a single member 30 to serve the same purpose as shown in FIGS. 3 and 4. In this case, there is a disadvantage that the member 30 cannot be used as a hood when it is in a position covering the distance ring 5 (FIG. 3), but it has the advantage that it can have a cleaner appearance than the first embodiment.

In addition, if the overall length of the lens is relatively short, there is no need to form a special hood part, and only the protective tube part is used, and this protective tube part is configured to protrude toward the subject so that it can fulfill the role of a hood. Other configurations are also possible.

Furthermore, in the first embodiment, the hood 1
A click stop mechanism (consisting of a spring 18, a recessed part 3b, etc.) is used as a mechanism for holding the lens 7 in a position protruding from the lens body and holding the protective tube 16 in a position covering the distance ring 5. However, the one shown in Figs. 3 and 4 uses a screw holding mechanism (a threaded portion 30a formed on the inner peripheral surface of a member 30 that serves as a hood and a protective tube, a lens holding tube, etc.) instead. A configuration consisting of threaded portions 3d and 31 formed in Such a configuration has the advantage that the member 30 can be held at each position more reliably than the first embodiment.

Furthermore, in each of the above embodiments, a configuration has been described in which the camera side is provided with a switch 14 that functions as a circuit switch for the built-in motor drive circuit and autofocus circuit, but such a circuit switch is specially provided on the camera body side. If the switch 14 is provided, there is no harm in omitting the switch 14 from the lens body.

Furthermore, as a modification of the above embodiment, it is also possible to configure the driven shaft 11 and the motor to be separated during manual focus adjustment. For this purpose, in the embodiment shown in FIGS. 1 and 2, for example, the driven shaft 11 is supported so as to be movable in its longitudinal direction, and a circumferential groove is provided in a part of the driven shaft 11, The configuration may be such that the arm extending from the detection pin 13 is fitted into the groove. With this configuration, the engaging portion 11a of the driven shaft can be moved in and out of the rear end surface of the mount member 1 in conjunction with the movement of the protective tube 16, and the engaging portion 11a can be moved in and out of the rear end surface of the mount member 1 during manual focus adjustment. By retracting the motor, the connection between the motor and the driven shaft can be severed. Disconnecting the motor reduces the load on the distance ring, which has the advantage of making it easier to rotate it.

Furthermore, in the above embodiment, when the protection tube 16 is moved to perform manual focus adjustment, the protection tube is configured to expose almost the entire distance ring 5 in its width direction (optical axis direction). However, this idea is not limited to this kind of configuration; in short, it is sufficient to ensure a width that allows the photographer's finger to touch the distance ring, and the width direction in the exposure state. Whether or not a portion is still covered by the protective tube is not the gist of this invention. Similarly, the position where the protective tube 16 covers the distance ring 5 (Fig. 1.
The point of this invention is not whether or not the distance ring is completely covered when the camera is moved to the position shown in the figure), but even if it is partially uncovered and exposed, the photographer's finger can still enter through the gap created by the protective tube. There is no problem in implementing it as long as it is not. In short, the structural significance of this protection tube is not so much whether to expose or cover the distance ring 5, but whether to prevent or allow the photographer's finger to reach the distance ring in both positions. It is something that has. Therefore, in this specification, terms such as "cover" and "expose" are used in relation to the protective tube 16, but
This term includes ``a portion of the distance ring remains uncovered and exposed'' and ``a portion of the distance ring remains uncovered and covered'' within the above limits. It should be understood that it also includes cases.

The switch 14 described in the embodiment comprises a fixed contact,
In the example shown, both the movable contact and the fixed contact are provided on the fixed barrel 2, but the movable contact can be provided on the inner peripheral surface of the rear end of the protective barrel 16 and the fixed contact can be provided on the outer peripheral surface of the front end of the fixed barrel 2. By doing so, it is possible to prevent the biasing force of the biasing spring for the detection pin 13 from being felt when the protective barrel 16 is operated.
The opening and closing of the switch 14 has been described as corresponding to the opening and closing of the drive circuit, respectively. However, if a switching circuit is interposed between the switch 14 and the drive circuit, the relationship between the opening and closing of the switch 14 and the opening and closing of the drive circuit can be reversed.

In the above embodiment, if a window is provided in a part of the protective tube 16 or if the protective tube 16 itself is made of a transparent material, it is possible to check the rotating state of the distance ring 5 from outside the lens barrel when it is driven by the motor. There are advantages to doing so.

In addition, in the above embodiments, if the camera side does not have a distance measuring circuit but only a motor drive circuit, or if both circuits are connected but they are not related to each other, the lens side The switch 14 functions as a power switch for only the motor drive circuit.

Effects This invention provides a protective cylinder 16 that is movable between two positions: a position that covers the operating ring for moving the lens, and a position that exposes the operating ring over its entire circumferential range. With this configuration, when the operating ring is driven by a motor (for example, during autofocus operation), the protective tube can be moved to a position that covers the operating ring in advance, so that the operating ring can be moved easily from the photographer's finger. can be prevented from being touched by someone. Therefore, when driven by the motor, there is no risk of applying a load to the operation ring due to finger contact, and quick focusing operation becomes possible. On the other hand, during manual operation, that is, when the protective tube is moved to a position where the operating ring is exposed, the operating ring is exposed all around the circumference, so the photographer can see from which direction. You can also rotate the operating ring by holding out your finger. Therefore, compared to the conventional example in which the direction in which a finger can be extended to the operating ring during manual operation is limited, there is an advantage that the operability and speed of operation can be greatly improved.

[Brief explanation of drawings]

1 and 2 are half-cut sectional views showing an embodiment of this invention, with FIG. 1 showing the state during focus adjustment by autofocus, and FIG. 2 showing the state during manual focus adjustment. . FIGS. 3 and 4 are half-cut sectional views showing other embodiments of the invention, with FIG. 3 showing the state during focus adjustment by autofocus, and FIG. 4 showing the state during manual focus adjustment. It is a diagram. DESCRIPTION OF SYMBOLS 1... Mount member, 5... Operating ring, 10... Driven member (gear), 11... Driven shaft, 13... Interlocking member (detection pin), 14... Switch, 16... Protective tube, 17
…Hood.

Claims (1)

[Claims for Utility Model Registration] 1. A driven lens configured such that the lens is moved in the optical axis direction by the rotation of an operating ring 5 arranged to be manually operated from the outside, and to be driven by a motor. In a lens barrel configured such that the member 10 is connected to the operating ring so that the operating ring can be rotated by a motor, the protective cylinder has a shape that can surround the outer peripheral surface of the operating ring. 16, and the lens barrel is configured to be movable between two positions: a position where the distance ring is covered and a position where the entire circumferential range of the distance ring is exposed. 2. A switch 14 constituting an opening/closing switch of a motor drive circuit is provided, and the switch is configured to be opened and closed in conjunction with the movement of the protective tube 16.
Lens barrel described in section. 3 Two positions: a position that protrudes toward the subject and a retracted position
A cylindrical hood 17 that can be moved between positions is provided, and the hood has a locus of movement that follows the protection tube 1.
Claim 1 or 2 of the utility model registration claim arranged so as to overlap a part of the locus of movement of item 7.
The lens barrel described in section. 4. The lens barrel according to claim 1 or 2 of the utility model registration claim, in which a hood portion is formed integrally with the protection tube 17.