JP3498006B2 - Lens barrel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system camera, and more particularly to an interchangeable lens barrel of a single-lens reflex camera, and more particularly to an AF single-lens reflex camera capable of manually adjusting a distance ring. Lens barrel. 2. Description of the Related Art In a so-called automatic focus adjustment (hereinafter referred to as AF) camera in which a distance adjusting cylinder is driven by a motor as a first power, manual focus adjustment (hereinafter referred to as M) as a second power.
When performing F), a switching mechanism for AF and MF is provided, and it is common to operate this to perform manual adjustment. When such a lens barrel is driven by a motor of the first power, the distance adjusting barrel is rotated by the first power, so that
There is a problem that the photographer carelessly touches the adjusting cylinder and affects the focus operation, and there is a problem in holding the camera and the lens barrel in the photographing state with respect to the adjusting cylinder. For this reason, the manual adjustment barrel and the distance adjustment barrel are separated, and the manual adjustment barrel is slid in the optical axis direction of the lens barrel, or a separate switching clutch is installed,
A method has been proposed in which the manual adjustment cylinder is shut off from the distance adjustment cylinder during the AF operation, and the manual adjustment cylinder does not rotate even when the distance adjustment cylinder operates (this is called a focus-free and commercialized). [0003] However, in any of the focus-free systems, the switching direction is different from the operation direction of the manual adjustment cylinder, so that the switching operation lacks smoothness. For this reason, a lens barrel that can be manually adjusted only when a manual force, which is the second power, is obtained for these switching operations has been desired. Accordingly, in the present invention, a clutch mechanism comprising an intermediate ring and its accessories is provided between a drive cylinder and a manual adjustment cylinder interlocked with a distance adjustment cylinder, and the manual adjustment cylinder is provided with a clutch mechanism. In operation, the intermediate ring is held in a neutral position with respect to the manual adjustment cylinder by the accessory, and the drive ring idles with respect to the accessory. By acting on the accessory, the intermediate ring, the accessory, and the drive cylinder are connected and integrated, so that the manual adjustment cylinder is configured to operate. When the manual adjustment cylinder is not rotated, the clutch mechanism is in a disengaged state. In the AF mode, the manual adjustment cylinder does not rotate even if the AF operation is performed. Then, in the MF mode, if the manual operation power is applied to the manual adjustment cylinder under the condition that the first power system is shut off automatically or manually, the clutch mechanism is connected by the manual force, and the rotational force is reduced. The drive cylinder is rotated, and as a result, focus adjustment is performed. The best embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a lens barrel on which the clutch mechanism of the present invention is mounted, and FIG. 2 is a cross-sectional view of a main part of the clutch mechanism taken along the line AA. In the drawings, the same members are denoted by the same reference numerals. In the sectional view of the lens barrel shown in FIG. 1, there are a front lens unit L1 and a rear lens unit L2 around the optical axis L0, and by moving the front lens unit L1 straight with respect to the rear lens unit L2, 2 shows an example of a lens barrel that can adjust the focus. The front lens unit L1 is held by a holding frame 1, and the rear lens unit L2 is held by a holding frame 2.
The helicoid part 3a of the distance adjusting cylinder 3 to which the holding frame 1 is fixed and the helicoid part 4a of the moving cylinder 4 are engaged with each other. You can do it. The movement of the inner tooth tube 6 in the optical axis direction is restricted by the protrusion 7a of the holding tube 7 fixed to the fixed tube 5, but the inner tooth tube 6 is rotatably supported. Internal teeth 6a are formed with internal teeth 6a on the inner diameter side, and mesh with a pinion 8 that rotates via a gear train that rotates by receiving a rotational force from a camera motor or a lens motor (not shown). . The gear train (not shown) includes a power transmission mechanism during AF and a disconnection mechanism during MF. The drive cylinder 9 integrated with the inner tooth tube 6 includes:
Since the interlocking lever 3b, on which the distance adjusting cylinder 3 is fixed, is fitted in the inner straight lever groove 9a, the rotation of the inner tooth tube 6 can be transmitted to the distance adjusting cylinder 3, and the moving cylinder 4 and the distance adjusting cylinder 3 can be transmitted. , The straight-moving position of the distance adjustment barrel 3 with respect to the moving barrel 4 and the front lens unit L1 of the holding frame 1 changes, and the focus adjustment of the lens barrel becomes possible. The manual adjustment cylinder 11 fitted to the clutch ring 10 is supported by the projection 7b so as to be freely rotatable while its movement in the optical axis direction is restricted. A sliding member 10 g is attached to the outer periphery of the clutch ring 10,
And an appropriate sliding relationship is maintained. FIG. 2 shows the arrangement of the drive cylinder 9, the clutch ring 10, and the manual adjustment cylinder 11 as viewed from the axial direction. Clutch ring 1 fitted in drive cylinder 9
0 is provided with a gap 10a provided with a concave portion with respect to the outer peripheral surface 9b of the driving cylinder 9, and the gap 10a of the clutch ring 10 is provided with an interlocking portion 11a of the manual adjustment cylinder 11, Spring 12a, 12b is provided in the gap in the circumferential direction,
Balls 13a and 13b are inserted. The inclined surfaces 10g and 10h are formed so that the gap becomes narrower as each ball advances in the spring-side circumferential direction. When the manual adjustment cylinder 11 is not operated, the balls 13a and 13b are pressed against the end faces of the interlocking portion 11a with the same amount of urging force by the urging forces of the springs 12a and 12b, respectively.
The balance is maintained so that the ball does not bite between the inclined surfaces 10g and 10h of FIG. Next, the operation will be described. At the time of AF, the manual adjustment cylinder 11 is held by hand, and a ball 13a is provided between the inclined surface (10g and 10h) of the clutch ring 10 and the outer peripheral surface 9b of the driving cylinder 9 due to the urging force of the springs 12a and 12b.
The clutch ring 10 is kept at a position where the clutch ring 10 and 13b do not bite. Therefore, the ball and the outer peripheral surface 9b
During this period, no holding force acts, and the drive cylinder 9 slides with respect to the ball. At the time of MF, when the manual adjustment cylinder 11 is turned in the direction of the arrow, the interlocking portion 11a pushes the ball 13a against the urging force of the spring 12a, and simultaneously pushes the end face 10b through the spring 12a, and the clutch ring 10 At this time, the clutch ring 10 moves slightly behind the ball due to the inertia force of the clutch ring 10 itself and the sliding resistance between the clutch ring 10 and the holding cylinder 7 at this time. As a result, the ball 13a bites between the inclined surface 10g of the gap 10a and the outer peripheral surface 9b, and the clutch ring 10 and the drive cylinder 9 are integrated and turned in the direction of the arrow. This allows manual adjustment in the left direction, but the same applies to adjustment in the right direction. When a manual force is applied to the manual adjustment cylinder 11 in the direction opposite to the arrow (right direction), the interlocking unit 11a is attached with a spring 12b. The ball 13b is moved against the power and the inclined surface 10 of the air gap 10a.
h and the outer peripheral surface 9b of the driving cylinder 9
When the ball 13b bites between the clutch ring 10 and the drive cylinder and is integrated, the rightward rotation can be adjusted. When the rotation of the manual adjustment cylinder 11 is stopped, the clutch ring 10 and the driving cylinder 9 stop with a delay due to the inertial force. Stopping the rotation means that the manual force is not applied to the manual adjustment cylinder 11 in either direction. Therefore, the clutch ring 10 is moved in the adjustment direction from the stop position by the restoring force of the spring 12a or 12b which has been pressed. The balls 13a and 13b are moved slightly, or the manual adjustment cylinder is slightly returned, so that the balls 13a and 13b are
It will be separated to the larger space of the inclined surface 10g or 10h of a. Therefore, the drive cylinder 9 and the clutch ring 1
0 is released, and the clutch ring 10 and the manual adjustment cylinder 11 become independent of the rotation of the drive cylinder 9. Note that M
At the time of F, since the interlock between the motor and the pinion 8 is interrupted in the gear unit (not shown), the motor does not rotate and the load does not become a load even if the internal tooth tube 6 rotates. FIGS. 3 and 4 show a perspective view and a sectional view of another embodiment of the present invention, in which a clutch ring and a manual adjustment cylinder are modified. In FIG. 3, projections 10e and 10f are formed on the clutch ring 10d. The two clutch plates 11c and 11d are formed integrally with the manual adjustment cylinder 11b, and have elasticity in relation to the constituent materials and the shape. This clutch mechanism is constructed as shown in FIG. 4, and when no manual operation force is applied, the bottom surfaces 11f, 11
g has a slight gap with the outer peripheral surface 9b of the driving cylinder 9c. When the manual adjustment cylinder 11b is rotated in the direction of arrow 12, the inertia of the clutch ring 10d and the sliding resistance between the clutch ring and the fixed cylinder 5 receive the resistance of the projection 10e. Displaced by force. Therefore, when the projection 10e further advances, the bottom surface 11f of the clutch plate 11c presses the outer peripheral surface 9b of the driving cylinder 9c to be frictionally coupled, and the driving cylinder 9c and the manual adjustment cylinder 11b rotate integrally. Next, when the rotation is stopped, the clutch ring 10d stops with a slight delay. Therefore, a restoring force acts on the manual adjustment cylinder 11b in the direction opposite to the direction of the arrow 13 due to the elastic force, and the pressing force on the outer peripheral surface 9b is released. The above operation is performed in the manual adjustment cylinder 11 shown in FIG.
The operation when b receives a manual force in the left direction of the arrow has been described, but the same operation is performed when a manual force in the direction opposite to the arrow (right direction) is received, and the drive cylinder 9c is adjusted from the manual adjustment cylinder 11b. It is possible to move. That is, the manual adjustment cylinder 11b
When a rightward turning force is manually applied to the clutch ring 11d, the tip of the clutch plate 11d
Therefore, the clutch plate 11d lowers the bottom surface 11g while resisting the elastic force, and presses the outer peripheral surface 9b of the drive cylinder 9c to be frictionally coupled, so that the drive cylinder 9c and the manual adjustment cylinder 11b are integrated. Rotation in the right direction becomes possible. In the case where the clutch ring 10d stops after the adjustment in the right direction, as in the case of the left direction, the clutch ring 10d is slightly delayed, and stops after a little too far. Therefore, the bottom surface 11g is lifted by the restoring force of the clutch plate 11, and the driving cylinder 9c is free from the outer peripheral surface 9b of the driving cylinder 9c. As described above, the ball is used to connect the clutch ring and the drive cylinder. However, it is needless to say that a cylindrical roller or the like may be used. Furthermore, although only one set of clutch units is shown in the description, a plurality of clutch units may be provided. According to the structure of the present invention, the clutch can be engaged and manual adjustment can be performed simply by rotating the clutch in the direction of manual operation, and the clutch is released when the operation is stopped. The operability can be realized, and there is no need to move the manual adjustment cylinder or the like back and forth in the optical axis direction, so that a compact configuration can be realized. As described above, according to the configuration of the present invention, when the MF mode is applied and a manual rotational force is applied to the manual adjustment cylinder 11 under the condition that the first power system is shut off. Only when the manual adjustment cylinder 11 and the drive cylinder 9 are connected to each other, the distance adjustment cylinder 3 can be adjusted manually. If the manual force is eliminated, the manual adjustment cylinder 11 and the drive cylinder 9 can be separated. In the AF mode, the manual adjustment barrel 3 has no relation to the rotation of the motor, and even if the user grips or touches the manual adjustment barrel 3 to hold the lens barrel, the automatic focus adjustment is prevented. No.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a lens barrel according to an embodiment. FIG. 2 is a sectional view taken along line AA of the embodiment. FIG. 3 is a perspective view showing a clutch mechanism of another embodiment. FIG. 4 is a sectional view of the clutch mechanism shown in FIG. 3; [Description of Signs] 1 Holding frame 2 Holding frame 3 Distance adjusting cylinder 3b Interlocking lever 4 Moving cylinder 5 Fixed cylinder 6 Internal tooth tube 7 Holding cylinder 8 Pinion 9 Drive cylinder 10 Clutch ring 11 Manual adjustment cylinder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 7/04 G02B 7/09

Claims (1)

(57) Claims 1. In a lens barrel having a distance adjusting cylinder in which a lens position of an optical axis can be moved by a motor power as a first power, the distance is adjusted by the first power. When the cylinder is driven, the manual adjustment cylinder does not rotate, and when the drive system of the first power is shut off , the manual adjustment cylinder is applied to the distance adjustment cylinder only when the second power that is the manual force is obtained. Connected, second power
A lens barrel having a clutch mechanism that enables the driving of the distance adjusting cylinder by, in the direction of the power which the second power is given to the manual adjustment barrel, the left direction of the distance adjusting cylinder
Clutch operation for movement and clutch movement for rightward movement
A lens barrel characterized in that the distance can be adjusted by the second power by a mechanism capable of obtaining a first movement .