JPH0216338Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a focus adjustment mechanism for a lens such as a photographic lens or a metering lens attached to a camera, a single exposure meter, or the like.

[Background and problems of conventional technology]

Conventionally, this type of focus adjustment mechanism includes a lens support member 1 for supporting a lens, as shown in FIG.
Helicoid screws 1a and 2a, which are male threads on one side and female threads on the other side, are cut in the distance ring 2 into which this lens support member 1 fits, and by rotating the distance ring 2 in an appropriate direction, the lens support member 1 Optical axis O-
Generally, the helicoid screw moves straight in the O′ direction to focus the lens, but compared to ordinary screws, it is difficult to match the male and female threads, and requires fairly precise machining or mold machining. Therefore, the cost of parts increased accordingly, making it difficult to provide an inexpensive device.

Therefore, as shown in FIG. 2, the projection 3 is formed on the lens support member 3 so as to protrude, and the focus adjustment member 4 is formed with an inclined surface 4a on which the projection 3a abuts, thereby driving the focus adjustment member 4. It is known that the lens support member 3 is moved straight back and forth in the direction of the optical axis O-O' for focusing by adjusting the contact position between the inclined surface 4a and the protrusion 3a. . However, the amount of lens extension at this time is as shown in FIG.
, the so-called lens extension amount to, the driving amount lo of the focusing member 4, and the inclination angle θ of its inclined surface 4a.
In this case, to=lotanθ, and when the drive amount lo of the focus adjustment member 4 is constant, the lens extension amount to is determined by the inclination angle θ of the inclined surface 3a formed on the focus adjustment member 4, In order to minimize the amount of displacement of the lens and to enable fine focusing adjustment, it is necessary to make the inclination angle θ of the inclined surface 4a considerably small. However, the frictional force acting on the contact point between the protrusion 3a of the lens support member 3 and the inclined surface 4a of the focusing member 4 increases in proportion to this inclination angle θ, and the lens support member is affected by this frictional force. 3 does not follow the movement of the focus adjustment member 4, and the lens cannot be smoothly extended to an appropriate position, making focus adjustment difficult.

[Purpose of the invention] The present invention has been made in view of the above-mentioned drawbacks, and it is possible to finely adjust the focusing without reducing the angle of inclination of the inclined surface, and the adjustment operation is also performed smoothly. It is an object of the present invention to provide an easy-to-adjust lens focusing mechanism.

[Summary of the idea]

In order to achieve the above object, the present invention includes a lens focusing mechanism that includes a first member having an inclined surface in the direction in which the lens is extended, a second member having an inclined surface intersecting this inclined surface, and a second member having an inclined surface intersecting the inclined surface. a lens support member having a protrusion that abuts at a point of intersection between the first and second inclined surfaces, or both of the inclined surfaces, and the point of intersection moves at least one of the first and second members. By making the lens movable and driving the lens supporting member to follow the movement of the intersection point, the amount of displacement of the lens extended with respect to the amount of movement of the movable member can be reduced without reducing the inclination angle of the inclined surface. This makes it possible to finely adjust the focus.

[Example of idea]

Hereinafter, the present invention will be described in detail based on the embodiments shown in the accompanying drawings.

FIG. 4 is an exploded perspective view showing a shutter device for a camera equipped with a lens focus adjustment mechanism according to the present invention. A lens focusing mechanism consisting of a focusing member (member) E, a focusing member (first member) F, and a lens barrel support base (second member) G, an aperture plate J, an aperture presser plate H, and a slide blade L. A shutter mechanism consisting of a rotary blade M, a release lever N, an operating lever P, a shutter board Q, a shutter opening/closing lever R, a flywheel member T, and a switch body W are arranged in sequence as shown in the figure. be.

The lens barrel holding plate spring A has an opening _A1 forming three holding plate spring pieces _A6 to _A8 that are bent in the downward direction of the optical axis, and mounting holes _A2 to _A5 , and has screws _A9. It is attached to the lens barrel support base G by a hook _G7 formed on the lens barrel support base G.

The lens holding plate spring B forms a ring-shaped lens holding part _B1 and a plurality of engaging claws _B2 that protrude radially from its outer circumference and are press-fitted and engaged with the inner surface _E2 of the protruding ring of the lens barrel E. This is to hold down a lens (not shown) in the tube E.

The lens barrel E has an inner surface E ₂ of a protruding ring into which the lens retainer plate spring B is press-fitted, and an opening E 1 that accommodates a lens (not shown) that is pressed by the lens retainer plate spring B, and an opening E ₁ from the outer periphery of the lens barrel. Holding plate spring piece A of the protruding lens barrel holding plate spring A ₆
A protrusion with a side surface pressed by A ₈
E ₃ and a protrusion E ₄ that protrudes downward in the direction of the optical axis O-O', and a lens holding plate spring B always maintains the optical axis O-O'.
A biasing force is applied downward in the O' direction, and the lens barrel is supported on the lens barrel support base G so as to be movable back and forth in the optical axis O-O' direction.

The focus adjustment member F has three movable guides _F2 having inclined surfaces inclined in the lens extending direction (optical axis O-O' direction) arranged at equal intervals on the upper end surface of the ring part _F1 , and Adjustment arm F ₃ protrudes outward from the outer periphery of F ₁ and forms a long hole F ₄
It is supported by the lens barrel support base G so as to be rotatable about the optical axis O-O'.

The lens barrel support base G is a cylindrical protrusion that protrudes around the optical axis O-O', and has an inner circumferential surface to driveably support the lens barrel E, and an outer circumferential surface to rotatably support the focusing member F. G ₁ and a fixed guide G ₂ forming an inclined surface that intersects with the inclined surface of the movable guide F ₂ in the focusing member F on the end face of this cylindrical protrusion G ₁ , and a lens barrel holding plate spring A. Supports G ₃ to G ₆ for attaching the , mounting holes G ₈ to G ₁₀ for attaching to the shutter board Q,
At least tap holes _G10 and _G11 and hole 12 are formed, and the shutter board Q is mounted with a certain gap therebetween.

The aperture plate J has a large aperture _J1 and a small aperture with different diameters.
_J2 , and has a protrusion _J3 , a drive operation arm _J4 , and a rotational shaft hole _J5 , and this rotational shaft hole _J5 is connected to the hole G of the lens barrel support base G by means of a shaft pin _J6 . ₁₂ , and by driving the drive operation arm _J4 , the optical axis O-O can be selectively changed between the large aperture J1 with a film sensitivity of ISO 400 and the small aperture aperture _J2 with a film sensitivity of ISO ₁₀₀ . 'The reflected light from the desired subject can be appropriately narrowed down.

The slide blade L has an exposure notch _L1 in the center,
The shutter opening/closing lever R protrudes through the elongated hole L ₃ that is fitted through the hole L ₂ through the pin Q ₁₅ implanted in the shutter board Q, and the fan-shaped elongated hole Q ₃ of the shutter board Q.
A hole _L4 is formed to fit the interlocking pin _R3 implanted in the shutter opening/closing lever R.

The rotary blade M has an exposure notch M ₁ at a position symmetrical to the exposure notch L ₁ of the slide blade L with respect to the optical axis O-O', and a fan-shaped elongated hole Q ₄ in the shutter board Q.
The elongated hole _M2 fits into the interlocking pin _R4 implanted in the shutter opening/closing lever R protruding through the shutter board Q, and the rotary shaft hole _M3 is rotatably supported by the pin screw _Q16 screwed into the shutter board Q. It is rotated by a shutter opening/closing lever R.

The release lever N is connected to the operating arm _N1 and the locking pawl.
N ₄ and a locking arm N ₂ forming a sliding surface N ₃ , a bent part N ₅ on which the arm P ₇ of the spring P ₆ of the operating lever P is hung, and a support shaft Q ₁₂ implanted in the shutter base plate Q. It has a shaft hole N ₆ into which it is rotatably fitted, and is always given a clockwise rotational habit by the biasing force of a spring P ₆ of the operating lever P.

The operating lever P has a connecting part _P1 that connects to a winding lever (not shown) that can be operated from the outside of the camera, a pin _P4 that is locked to a locking claw _N4 of the release lever N when winding the camera, and a shutter board that protrudes from the back side. Q
The pin P ₅ collides with the pin T ₂ installed in the flywheel member T through the fan-shaped elongated hole Q ₂ , and the spring P ₆
A spindle fitted to the outer periphery and implanted in the shutter board Q
It has a support hole P ₃ that rotatably fits into Q ₁₃ and a notch P ₂ for hanging the arm P ₈ of spring P ₆ , and the support shaft Q of the shutter board Q is always rotated clockwise by spring P ₆ . Rotation habits are given around ₁₃ .

The shutter board Q has a hole _Q9 for installing a pin _Q15 that supports the slide blade L in a movable manner, and a rotary blade M.
a tap hole Q ₈ to which a pin screw Q ₁₆ is fixed, which rotatably supports the release lever N and the actuation lever P; and support shafts Q ₁₂ and Q ₁₃ which rotatably support the release lever N and the operating lever P;
In addition to fan-shaped elongated holes Q 3 and Q ₄ through which _the pin P ₅ of the operating lever P and the interlocking pins R ₃ and R ₄ of the shutter opening/closing lever R pass through, respectively, an opening Q ₁ that opens around the optical axis; A support shaft _Q14 that protrudes from the back side and rotatably supports the shutter opening/closing lever R, and tap holes _Q15 to attach the lens barrel support board G.
Q ₁₇ , a hole Q ₁₁ for attaching the switch body W, a tap hole Q ₁₀ for screwing with a screw W ₆ , and attachment holes Q ₅ to Q ₇ for attaching to the camera are formed at least.

The shutter opening/closing lever R includes an interlocking pin R ₃ that slides the slide blade L, an interlock pin R ₄ that rotates the rotating blade M, and a pin R ₅ protruding from the back side that fits into the hole T ₄ of the flywheel member T. , the screw hole R ₆ of the screw R ₇ that integrally holds the flywheel member T, the hole R ₁ that rotatably fits into the support shaft Q ₁₄ implanted in the shutter board Q, and the flywheel member T. _A shaft _R2 having a hole _R1 that fits into the hole _T1 of It is given mobility.

The flywheel member T forms holes T ₁ and T ₄ and a tap hole T ₅ for integrally attaching to the shutter opening/closing lever R, and protrudes from the back side with the pin T ₂ that collides with the pin P ₅ of the operating lever P. Spring T ₇
A pin T ₃ on which the shutter opening/closing lever R is rotated counterclockwise is received by the impact force of the operating lever P to rotate the shutter opening/closing lever R counterclockwise against the spring T ₇ . The rotary blade M is driven to perform exposure control.

The switch body W is attached to the shutter board _Q by forming a protruding pin W ₄ that fits into the hole Q ₁₁ of the shutter board Q and a screw hole W 5 on the switch base W 1 and a screw hole W ₅ that fits into the hole Q 11 of the shutter board Q, and is attached to the shutter board Q by a screw W ₆ . Contact piece W ₇ switched to ON/OFF state by pin R ₅
Synchro switch consisting of and W ₈ and contact pieces W ₉ and W ₁₀
It has a date switch.

Next, a series of operations of the shutter device will be explained.

First, regarding the operation of the focus adjustment mechanism of the lens according to the present invention, we will explain the operation of the focus adjustment mechanism of the lens in FIG. This will be explained with reference to FIGS. 6A to 6C, which are diagrams of the operation state of the focus adjustment mechanism. As shown in FIG. 4, the focus adjustment member F, lens barrel E, lens retainer plate spring B, and lens barrel retainer plate spring A are assembled on the lens barrel support base G in this order, and then attached to the shutter board Q. By attaching the lens barrel support base G, the lens focus adjustment mechanism in the shutter device can be assembled as shown in the side view of FIG. Therefore, when adjusting the focus of the lens, as shown in FIG. 5, the screw _F9 that fixes the focus adjustment member F to the lens barrel support substrate G after the focus adjustment is slightly loosened to make the focus adjustment member F rotatable. Then, when the adjustment arm _F3 of the focus adjustment member F is rotated in an appropriate direction, the focus adjustment member F
The protrusion E ₄ is attached to the lens barrel holding plate spring A by straddling the inclined surface of the movable guide F ₂ and the inclined surface of the fixed guide G ₂ of the lens barrel supporting board G that intersects this inclined surface.
The lens barrel E is pressed and abutted by the urging force of
is rotated in the rotational direction of the focus adjustment member F and moves forward or backward in the optical axis direction as shown in FIGS. 6A to 6C to focus the lens, and then loosens first. The focus adjustment is completed by tightening the screw _F9 and fixing the focus adjustment member F to the lens barrel support base G. The amount of lens extension at this time is determined by the lens extension amount t'o and the movable guide in the focus adjustment member F, as shown in Fig. 7.
Inclination angle θ (0 < θ < 90°) and amount of movement of the slope of F ₂
lo, Fixed guide on lens barrel support board G
When the inclination angle α (0 < α < 90°) of the slope of G ₂ is, to' = lotan θ (1 + tan θ / tan α). For example, if θ = α, to' = (lotan θ) / 2 = to / 2, which means that the amount of extension is half of the amount of extension to in the conventional structure explained in Figure 3, and generally
The relationship to > to′ allows the amount of lens extension displacement to be reduced and fine adjustment to be possible.

8 to 10 show modified examples of the first embodiment, in which the inclined surface of the movable guide F2 formed on the focus adjustment member F and the inclined surface of the movable guide _F2 formed on the lens barrel support substrate G are shown. This shows the state in which _the protrusion _E4 of the lens barrel E is in contact with the inclined surface _of the fixed guide _G2 . For example, in _FIG . Secure the end E ₄ ″ to the guide
_G2 is in contact with the inclined surface of G2.
In the figure, the tip of protrusion E ₄ forms inclined surfaces E _{4 ′} and E ₄ ″ having the same inclination angle as the inclined surfaces of both guides F _{2 and} G ₂ , and the tip of protrusion E 4 is Cross point FG
Furthermore, Fig. 10 shows a protrusion.
Point the tip of E ₄ to the intersection point of both guides F ₂ and G ₂ .
The lens is brought into contact with the FG, and in both cases fine focusing adjustment can be made in the same manner as in the first embodiment.

Next, to explain the operation of the shutter mechanism, after completing the focus adjustment of the focus adjustment mechanism,
The operating lever P is rotated counterclockwise against the spring P ₆ by a winding operation using a camera's winding lever (not shown), and the operating lever P is at the charge position.
The shutter is maintained in the charged state by locking and holding the pin _P4 with the locking pawl _N4 of the release lever N. At that time, pin P ₅ of this operating lever P
The shutter opening/closing lever R, which rotates integrally with the flywheel member T that abuts the pin _T2 by means of a spring _T7 , rotates slightly clockwise, thereby moving the slide blade L and the rotary blade M further in the closing direction. Drive. Therefore, by pressing the operating arm _N1 of the release lever N and rotating it counterclockwise, the locking state of the operating lever P is released, and the operating lever P is quickly turned clockwise by the biasing force of the spring _P6 . Rotate in the direction and return. When the pin _P5 of the operating lever P collides with the pin _T2 of the flywheel member T and rapidly rotates the flywheel member T counterclockwise against the spring _T7 , the flywheel member T The slide blade L is rapidly driven to the right by the shutter opening/closing lever R, which rotates counterclockwise in unison with the shutter, and the rotating blade M is rapidly driven counterclockwise to open the shutter. Exposure control is performed by rotating the shutter opening/closing lever R back clockwise by the acting spring _T2 and closing the shutter.

Although the above embodiment is a so-called fixed focus adjustment mechanism, if an automatic focus detection device is provided and the focus adjustment member is driven by a motor that is rotationally controlled by this device, an automatic focus adjustment mechanism can be realized. As an adjustment mechanism, focus can be adjusted according to the distance of the subject. Furthermore, although the shutter mechanism has an extremely simple structure and has a single shutter speed, an aperture setting member is provided so that the amount of rotation of the shutter opening/closing lever can be varied according to the brightness of the subject. Therefore, a shutter device that can easily vary the shutter speed and aperture can be constructed, and the shutter opening/closing lever is composed of a shutter opening lever and a shutter closing lever, and the operating timing of the shutter closing lever is controlled by an electromagnet. It can also be easily used as an electromagnetic shutter mechanism by controlling it with .

FIG. 11 shows a second embodiment of the present invention, in which E' is the lens barrel (lens support member), and F' is the lens extending direction (optical axis O-O' direction). A movable guide that forms an inclined surface that slopes to
A focusing member (first member) having a focus adjustment member F ₂ ′, G′ movably has a fixed guide G ₂ ′ forming an inclined surface intersecting the inclined surface of the focusing member F′. The supporting member is used to constantly abut the protrusion _E4 ' of the lens barrel E' across the inclined surfaces of both guides _F2 ' and _G2 ' by means of a spring _A7 ' consisting of a lens barrel holding plate spring, etc. In this state, by sliding the focusing member F' in an appropriate direction, the intersection point can be moved as shown in FIGS. 6A to 6C and FIG. 7 in the same manner as in the first embodiment. This allows for fine focusing adjustment.

In each of the above embodiments, only the first member is movable, but it goes without saying that the second member may be movable at the same time.

[Effect of idea]

As detailed above, in the present invention, at least one of the two members having sloped surfaces that intersect with each other is movable, and the movement of the intersecting portion drives the lens support member and focuses the lens. By doing so, it is possible to reduce the amount of lens extension displacement relative to the amount of movement of the movable member without reducing the inclination angle of the inclined surface, and fine adjustment of focusing is possible. Since the frictional force acting on the abutting surface can also be kept small, it is possible to provide a lens focus adjustment mechanism in which the lens support member smoothly follows the operation of the movable member, making it easy to adjust the focus.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams for explaining the background of the prior art, and FIG. 4 is a first diagram of a shutter device in a camera equipped with a focus adjustment mechanism according to the present invention.
FIG. 5 is a partially sectional side view showing the main parts of the focus adjustment mechanism in FIG. 4, and FIGS. 6A to 6C are in FIG. 5. FIG. 7 is an explanatory diagram for explaining the relationship between the amount of lens extension according to the present invention, and FIGS.
FIG. 11 is a perspective view showing a second embodiment of the focus adjustment mechanism according to the present invention. In the figure, A...Lens barrel holding plate spring, B...Lens holding plate spring, E...Lens barrel, _E4 ...Protrusion, F...Focus adjustment member, _F2 ...Movable guide,
G... Lens barrel support base, G ₂ ... Fixed guide,
H...Aperture holding plate, J...Aperture plate, L...Slide blade, M...Rotating blade, N...Release lever, P...Operation lever, Q...Shutter board, R
...Shutter opening/closing lever, T...flywheel member, W...switch body.

Claims (1)

[Scope of utility model registration request] In a lens focus adjustment mechanism that drives a lens support member and adjusts the lens extension position to perform focusing, the first member has an inclined surface in the direction in which the lens is extended, and an inclined surface that intersects with this inclined surface. and a lens support member having a protrusion that abuts across the first and second intersection points or slopes, and at least one of the first and second members is connected to the intersection point. A lens focus adjustment mechanism characterized by being configured to be movable so that a point moves.