JPS6333684B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an interchangeable autofocus lens.

Various automatic focus adjustable cameras (hereinafter referred to as AF cameras) have already been proposed and put into practice. The currently commonly used AF camera is a 35mm lens shutter camera. Since there is no need to change lenses with this type of camera, a slightly wide shooting lens suitable for automatic focus adjustment (AF adjustment) is used. This is because this type of lens can tolerate some degree of uncertainty in distance measurement performance and poor adjustment accuracy. However, such cameras are not satisfactory, and there is a strong desire to use lens groups with different focal lengths and to perform AF adjustment.

In providing interchangeable lenses with adjustable AF
List possible problems related to AF adjustment and lens changes.

The same goes for 35mm lens shutter cameras, but you can operate the lens barrel from the camera body side.
When performing AF adjustment, if your hand or the like touches the lens barrel, it is expected that this will interfere with the AF adjustment. However, with lens shutter AF cameras,
The lens is a wide type, and the amount of protrusion from the camera body to the tip of the lens is not very large. Also, the device that drives the lens barrel is installed to protrude to the periphery, and there is a cover to protect the device. It covers the surrounding area and prevents your hands from touching the lens barrel when adjusting AF.

However, since interchangeable lenses for AF use such a configuration, it is difficult to adopt such a configuration, and at least a considerable portion of the lens barrel must be held by hand in order to change the lens. These are contradictory demands.

It is known that it is difficult to photograph subjects with low contrast due to insufficient lighting with an AF camera. Under these conditions, instead of using AF adjustment, the conventional manual adjustment (hereinafter referred to as
MF adjustment) is preferably possible.
In particular, users who wish to use interchangeable lenses may have a desire to perform MF adjustment even if AF adjustment is possible.

That is, allowing users to selectively use either AF adjustment or MF adjustment can uniformly satisfy users with various preferences. Furthermore, in newly provided AF cameras with interchangeable lenses, it would be better for users to configure the system to allow the use of lenses that only allow conventional MF adjustment.

This also applies to newly available AF lenses.If this lens is made MF adjustable, it can be used as an MF adjustable lens even for conventional cameras that do not have an automatic focus adjustment device. This makes it possible to provide compatibility and satisfy a wide variety of user requirements.

Next, by configuring a system like the one described above, it is possible to identify what kind of lens (AF, MF, etc.) is installed on the camera body, and the user can easily know this through a display, etc. It is necessary to keep it like this.

We also offer interchangeable lenses for both AF and MF.
When attached to a camera equipped with a device capable of performing any of these functions, the mode (AF or MF) selected on the camera side is automatically transmitted to the lens.
It is preferable that a state is formed on the lens side in which a corresponding operation can be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an interchangeable automatic focus adjustment lens that can be attached to and removed from a camera body and that also enables manual focus adjustment by covering most of the functional parts of the lens with an outer cylinder. .

To achieve the above object, an exchangeable autofocus lens according to the present invention is provided integrally with a coupling part to a camera body and extends forward, and is provided with an aperture window to allow the lens to be driven. a fixed outer cylinder that covers most of the fixed outer cylinder; a manual distance adjustment ring that rotates with movement in the optical axis direction being restricted by the outer periphery of the fixed outer cylinder;
an inner cylinder that rotates within the fixed outer cylinder and is provided with a distance display in a portion corresponding to the opening window of the manual distance adjustment ring; and an inner cylinder that can rotate forward and backward with respect to the inner cylinder and that moves straight with respect to the fixed outer cylinder. The guided lens barrel and
a rotation transmission mechanism from the camera body that transmits the rotation output of the automatic focus adjustment device of the camera to the inner cylinder;
A gear of an autofocus drive ring that rotates integrally with the inner cylinder is connected or disconnected within the fixed outer cylinder by a switching operation to a gear of a manual disk that is rotated integrally within the fixed outer cylinder by the distance adjustment ring. The clutch comprises a gear, and enables manual focus adjustment when the clutch connects the inner cylinder and the distance adjustment ring, and automatically adjusts the focus by disconnecting the inner cylinder and the distance adjustment ring. is configured to allow

A more detailed explanation will be given below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a lens according to the present invention, and FIG. 2 is an external view.

This embodiment is configured to be able to switch between AF and MF.

The bayonet mount 1 forms a male bayonet which is a means for coupling to the camera body.

An annular fixing member 2 is screwed to the bayonet mount 1.

The outer cylinder 3 is screwed to the fixing member 2 and has a square hole 3a in its upper part. In the front part of the square hole 3a of the outer cylinder 3 (the left side in the figure, the part facing the subject), a scale indicating the depth of field is provided by engraving or printing. A straight key metal fitting 31 is fixed to the outer cylinder 3, and this metal fitting 31 functions as a guide means for moving a lens frame, which will be described later, in a straight line.

The decorative frame 4 is fixed to the mount 1 with screws, and is provided with a plurality of notches for projecting a lens driving pin 72a, an automatic aperture lever 10, etc. rearward (towards the body). Further, a bearing 41 is caulked in the upper part in the figure.

This bearing plays the role of supporting the shaft of the clutch mechanism for switching between AF and MF.

The parts described above are immovable parts that are fixedly provided.

A manual distance ring 6, which is a manual distance ring, is rotatable around the outer periphery of the fixed member 2, and its movement in the optical axis direction is restricted by the outer cylinder 3 and bayonet mount 1. An axial groove 6a is provided in a part of this ring 6 (lower side in the figure), and a disc 61 serving as a manual transmission plate is inserted into a circumferential hole 2a of the fixing member 2.
It passes through and fits into the groove 6a. When the manual distance ring 6 is rotated, it can rotate together with the disk 61 within a certain range. The disk 61 is the fixed member 2
A gear portion 61a is provided on the inside of the clutch 61, and functions as a switching clutch mechanism.

The lead groove ring 7 constituting the inner cylinder is in a fit-fit relationship with the inner periphery of the fixing member 2, and a lead groove is provided in the circumferential direction. This rotation of the lead groove ring 7 moves the lens forward and backward.

A distance scale ring 71 is integrally provided on the outer periphery of this lead groove ring 7.

In this embodiment, the front end of the distance scale ring 71 is connected to the outer cylinder 3.
The rear end faces the fixing member 2 and suppresses backlash of the lead groove ring 7 in the optical axis direction. Also, this lead groove ring 7
An AF drive ring 72 that supports a distance AF drive pin 72a so as to project rearward is screwed to the AF drive ring 72. A toothed portion 72b is provided on a portion of the inside of this AF drive ring 72, and serves as a part of the clutch mechanism.

The aperture barrel 8 constituting the lens barrel is in a fit-fit relationship with the inner periphery of the lead groove ring 7, and rotatably supports a roller 81 that engages with the groove of the lead groove ring 7 with a screw. This aperture cylinder 8 is provided with a linear keyway 8a as shown above.
Since the rotation is restricted by the straight-advance fitting 31, the lead groove ring 7 can be moved forward or backward by rotation. This aperture barrel 8 is provided with a filter ring, a front lens group, an aperture mechanism (diaphragm blades, chrysanthemum seat, etc.), and a rear lens group.

An AF/MF switching clutch (abbreviated as A-M switching clutch) shaft 9 is supported by a bearing 41 provided on the above-mentioned decorative plate 4 and a disc 5 so as to be movable forward and backward. A gear 91 is located on the tip side of this shaft 9.
A connecting plate 92 is caulked to the connecting plate 92.

The other end of the plate 92 passes through a notch in the lead groove ring 7 and a notch in the fixing member 2 and is coupled to the pin 21 . The pin 21 is supported by holes in the bayonet mount 1 and the fixing member 2, and is attached to the plate 92.
It is placed in the right direction (toward the camera body) in the figure.

The A-M switching clutch shaft 9 is also pushed to the right in the figure by a spring. The reason why the two related axes are biased toward the camera body by independent springs is to ensure smooth operation of both axes.

Further, pin 21 and pin 9 have the same function when pushed in from the body side. Either one can be omitted depending on the configuration of the camera. The automatic aperture lever 10 is rotatably attached to the mount 1 by a snap spring, and its other end is engaged with a chrysanthemum seat within the aperture barrel 8.

Although not shown, the automatic aperture lever 10 is biased clockwise by a spring.

When an interchangeable lens with the above configuration is connected to a camera body that is capable of AF adjustment, it will operate as an AF adjustment lens, and if the camera body is in the MF adjustment state or is a body exclusively for MF adjustment.
Operates as a lens for MF adjustment.

The lens can be attached and detached by holding the fixed outer tube.

Below is the operation of the lens with the above configuration in AF mode,
The explanation will focus on switching the MF mode.

When the lens is not attached to the camera, the lens is in MF mode.

In this MF mode, clutch pinion 91 is MF
It is formed by being coupled to the internal teeth 61a of the disc 61 and the tooth portion 72b of the AF drive ring 72.

In other words, both the pin 9 and the pin 21 are formed in a state where they are not pushed from the body direction.

In this state, when the MF ring 6 is rotated, the MF disk 6 is connected to the ring 6 at the part 6a.
1 rotates, this gear rotates the clutch pinion 91, which causes the AF drive ring 72 to rotate. The AF drive ring 72 is the lead groove tube 7
Since it is integrated with the lead groove tube 7, it can be rotated.
The aperture cylinder 8, which is connected to the groove via a roller 81, advances and retreats while being guided by a linear key fitting.

At this time, the display on the distance scale ring 71, which rotates together with the lead groove tube 7, can be observed through the window 3a of the fixed outer tube 3.

Even if the lens is connected to the camera body, if the clutch shaft 9 and pin 21 are not pushed from the body side and are in the state shown in Figure 1, then the MF
in mode.

Next, I will explain the AF mode. In the AF mode, the A-M switching clutch shaft 9 or pin 21 is pushed by engagement with a mechanism on the camera body side, and the clutch pinion 91 moves to the left in FIG.
It is formed when it is coupled only with the gear of the AF drive ring 72 and is no longer coupled with the gear of the MF disk 61. At this time, if you rotate the MF ring
The MF disk rotates, but this rotation is not transmitted anywhere. In other words, the MF ring becomes free. From the camera body side, AF drive pin 72a
When rotation is transmitted from an AF drive device (not shown), the AF drive ring 72 and the lead groove cylinder 8 integrated therewith rotate, and the aperture cylinder 8 is moved forward and backward in the same manner as in the MF mode.

As explained above, according to the present invention, it is possible to provide an AF-adjustable interchangeable lens group.

It also appears that MF adjustment is possible.

It is also possible to apply the configuration described in detail above to automatic control or manual control of the aperture for exposure adjustment. The aperture signal from the camera side is transmitted to the aperture mechanism, and when using a manual aperture ring, the manual distance ring can be replaced with a manual aperture ring.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a lens according to the present invention, and FIG. 2 is a plan view showing the external appearance. 1...bayonet mount, 2...fixing member,
3... Fixed outer cylinder, 31... Straight key fitting, 4...
Decorative frame, 41... Bearing, 5... Fixed disc, 6...
Manual distance adjustment ring (MF ring), 6a...Connection groove,
61...Manual (MF) disk, 61a...Gear portion, 7...Inner tube (lead groove tube), 71...Distance scale ring, 72...Auto focus (AF) drive ring, 72a...AF drive Pin, 8... Lens barrel (aperture cylinder), 81... Roller, 9... A-M switching clutch shaft, 91... Clutch pinion, 92...
Connecting plate, 10... automatic aperture lever, 21... pin.

Claims (1)

[Claims] 1. A fixed outer cylinder that is provided integrally with the connecting part to the camera body, extends forward, is provided with an aperture window, and covers most of the driven part of the lens; a manual distance adjustment ring that rotates with limited movement; an inner cylinder that rotates within the fixed outer cylinder and is provided with a distance display in a portion corresponding to the opening window of the manual distance adjustment ring; a lens barrel that is rotatable forward and backward with respect to the fixed outer barrel and guided linearly with respect to the fixed outer barrel; a rotation transmission mechanism from the camera body that transmits the rotational output of the automatic focus adjustment device of the camera to the inner barrel; and the distance adjustment mechanism. A gear of an autofocus drive ring that rotates integrally with the inner cylinder is connected or disconnected within the fixed outer cylinder by a switching operation to a gear of a manual disk that is rotated integrally within the fixed outer cylinder by a ring. comprising a clutch, the clutch enables manual focus adjustment when the inner cylinder and the distance adjustment ring are connected, and the clutch disconnects the connection between the inner cylinder and the distance adjustment ring to enable automatic focus adjustment. Interchangeable automatic focusing lens.