JPS60146209A - Photographic lens barrel - Google Patents

Abstract

PURPOSE:To prevent a deformation of a lens barrel and a variation of a groove width, caused by cut-opening of a groove end by providing a notch escape part communicating with a slide groove, on one end part of a cylinder surface on which a slide groove engaged with a slide projection is formed. CONSTITUTION:The second rotary cylinder 9 is made eccentric and inserted into the first rotary cylinder 16, and when the top part of a slide projection 15 provided as one body on the cylinder 9 passes through a notch escape part 16c provided on the incide circumference of the cylinder 16, the projection 15 is engaged with a slide groove 16a of the cylinder 16. If a lens barrel is formed in a state that the groove end is cut-opened, instead of such a constitution, a motion between the slide projection and the groove becomes hard due to a deformation of the lens barrel and a variation of a groove width, or a gas is generated, and it is feared that an unsmooth lens motion, an out-of-focus, etc. are caused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of a photographing lens mirror having a pair of cylindrical members that move relative to each other along the optical axis of the photographing lens.

[Background of the invention]

As camera bodies become smaller and lighter, the camera lenses attached to them can also be made lighter and more compact. In order to make the photographic 1/lens smaller and lighter, it is desirable to make the photographic optical system itself smaller and lighter, but there is a limit to how small and light it can be made due to the performance of the 1/lens, such as focal length and brightness. . Therefore, it is necessary to reduce the thickness of each of the lens barrels that are fitted in layers in a photographing lens barrel that holds the photographic optical system, thereby reducing the size and weight.

On the other hand, in order to transmit the movement of the operating member operated for focus adjustment or zooming to the internal movable lens barrel and move all or part of the photographic lens optical system, a sliding groove such as a linear groove or a cam groove is used. A pair of lens barrels overlapped on the inside and outside are configured to move relative to each other in the optical axis direction by a so-called bottle-groove connection between a groove and a sliding protrusion (including a bottle and a key) that engages with the sliding groove. There are many. in this case,
Generally, the sliding protrusion is screwed into one lens barrel by passing through a sliding groove with closed ends formed in the cylindrical surface of the other lens barrel. However, in order to increase the thread length for screwing the sliding protrusion, the lens barrel on which the sliding protrusion is provided had to be made thick.

In addition, if the lens barrel cannot be made thick, the lens barrel can be made thin by crimping a sliding pin like a rivet to the cylindrical surface of the lens barrel in advance, and the sliding pin can be attached to the other side. In order to engage the sliding groove provided on the lens barrel,
It is known that the sliding groove is formed by extending it until it reaches one end surface of the lens barrel. However, if the sliding groove is extended until it reaches one end face and the groove end is cut open, the lens barrel will not only deform;
The groove width of the sliding groove also varies and is not constant, and the movement between the sliding groove and the sliding pin that engages with the sliding groove becomes stiff, or there is play between the sliding groove and the sliding pin. Therefore, not only does the movement of the operation part for focus adjustment and zooming become unsmooth, but also there is a risk of blurring of focus due to the movement of the lens in the optical axis direction.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks of the conventional photography 1/lens lens, and provides a photography 1/lens that is smooth in operations such as focus adjustment, does not cause out-of-focus, and is lightweight and compact in appearance. purpose.

[Summary of the invention]

In order to further achieve the above objectives, the present invention provides a pair of cylinders provided with a lens barrel such that one of the lenses moves relative to the other along the optical axis (2). Among the members, a sliding protrusion is integrally provided on the cylindrical surface of one cylindrical member, and a sliding groove that can be engaged with the sliding protrusion is formed on the other cylindrical member, and the cylindrical surface of the other cylindrical member is provided with a sliding protrusion. A notch relief part that communicates with the sliding groove is formed at one end of the surface, and when the pair of cylindrical members are assembled, the sliding protrusion passes through the notch relief part and connects with the sliding groove. The technical point is that they should be configured so that they engage with each other.

〔Example〕

Embodiments of the invention will now be described in detail as illustrated in the accompanying drawings.

FIG. 1 is a partially longitudinal side view of an embodiment of the present invention, showing a state in which the distance is adjusted to infinity, and FIGS. 2 and 3 are cross sections AA and B- It is a sectional view showing B cross section.

In FIG. 1, a fixed lens barrel 2 having a lens-side bayonet member 1 at its right end that can be attached to a 1/lens mount on the camera body side (not shown) has a fixed lens barrel 2 (not shown) provided in a second movable lens L2. A diaphragm preset ring 3 interlocked with the diaphragm device is rotatably provided on its outer periphery. Also,
Inside the fixed lens barrel 2, a linear guide key 5 that is long in the optical axis direction and engages with a key groove 4b formed in the linear helicoid barrel 4 having a male helicoid screw 4a is provided integrally with the fixed lens barrel 2. Furthermore, a female helicoid screw 2a is provided on the inner peripheral surface of the fixed lens barrel 2.

Between the female helicoid screw 2a of the fixed lens barrel and the male helicoid screw 4a of the linear helicoid tube 4, there are helicoid screws 6a and 6b on the inner and outer peripheries that are screwed into both helicoid screws 2a + 4a, respectively. An intermediate helicoid tube 6 is provided. These helicoids 2 a
+ 4 a + 6 a + 6 b completes the construction of the double helicoid delivery mechanism, and the intermediate helicoid cylinder 6
When rotated clockwise (direction of arrow R) in FIG. 2, the intermediate helicoid tube 6 rotates and the helicoid screw 2
Part 1 moves to the left in the figure according to the lead of a, and at the same time moves straight to the left relative to the intermediate helicoid cylinder 6 according to the lead of the helicoid screw 4a. Configured to move.

At the left end of the straight-moving helicoid tube 4, there is a second moving lens group L.
A second lens group holding cylinder 7 that supports the lens 2 inside is fixedly installed with machine screws 8, and a male helicoid screw 7a is provided at the left end of the second lens group holding cylinder 7. The lead of this male helicoid screw 7a is formed to be thicker than the lead of the male helicoid screw 4a of the straight helicoid cylinder 4.

At the left end of the second rotary cylinder 9, which has a female helicoid screw 9a that is screwed into the male helicoid screw 7a of the 21st/lens group holding cylinder 7, there is a first rotary cylinder 9 that supports the first movable 1/lens group L1.
A linear inner cylinder 11 that screws and holds the lens frame 10 is rotatably supported, and its rotation is controlled by an optical axis formed in the second lens group holding cylinder 7 across the helicoid screw 7a. This is prevented by a keyway 7b that is long in the direction and a linear key 12 that engages with this keyway 7b. The linear key 12 is fixed inside the linear inner cylinder 11 with a small screw 13 as shown in FIG. has been done.

Note that reference numeral 14 is an adjustment ring for adjusting the reference interval (interval when the distance is adjusted to infinity) l between the first moving lens group L1 and the second moving lens group L2.

On the other hand, a sliding protrusion 15 is integrally formed on the outer periphery of the right end of the second rotary cylinder 9 so as to protrude from the outer periphery.
4-i, it engages with a sliding groove 16a that is long in the optical axis direction and is formed in the first rotating barrel 16 that covers the second rotating barrel 9 so as to penetrate through the circumferential surface thereof. At the center of the sliding protrusion 15, a sliding groove 15a is provided, as shown in the enlarged cross-sectional view of FIG. A countersunk screw 17 is installed in the center of the slot 15a, and by screwing in the countersunk screw, the slot 15 is opened.
It can be adjusted so that a opens and both sides of the sliding protrusion 15 lightly touch the sliding groove 16aK.

Furthermore, a counterbore hole 16b that is long in the circumferential direction is provided on the outer periphery of the first rotary cylinder 16, as shown in FIG. is fixed to the outer periphery of the left end of the intermediate helicoid cylinder 6 so as to be rotatably adjustable.

In addition, a sliding groove, 1
6a, an arc-shaped cutout relief portion 1.6e is provided, and as shown in FIG.
When the sliding protrusion 15 is made eccentric with respect to the notch, the sliding protrusion 15 passes through the notch relief portion 160 and engages with the sliding groove 16a.
An appropriate gap S is provided between the outer peripheral surface of the second rotating barrel 9 and the inner peripheral surface of the first rotating barrel 16. Further, at the left end of the first rotary cylinder 16, there is a notch relief portion 16C and the gap S.
A tightening ring 19 is screwed on and covers the holder from the outside.

On the other hand, a fixed lens barrel 2 is provided on the outer periphery of the intermediate helicoid barrel 6.
A distance scale ring 20 is rotatably fixed with a machine screw 21 (or adhesive tape may be used) so as to cover the outer periphery of the distance scale ring 20 and the first rotary cylinder 1.
6, the distance adjustment operation ring 22 is fitted to the outer circumference of the tightening ring 1.
It is fixed by tightening with 9.

Next, the assembly and adjustment of the photographing lens barrel of the embodiment described above will be explained.

First, before attaching the 21st/lens group holding cylinder 7 that supports the 21st/lens group L2 to the linear helicoid cylinder 4 with machine screws 8, the second rotating cylinder 9 is attached to the second lens group holding cylinder 7. Screwed into the recoid screw 7a, the through hole 11a of the straight inner cylinder 11
The straight key 12 is inserted into the key groove 7b through the screw 12, and the straight key 12 is attached and fixed to the straight inner cylinder 11 with the machine screw 13. Next, the tightening ring 19 and the distance adjustment operation ring 22 are removed to expose the first rotating barrel 16.

In this state, the sliding protrusion 15 of the second rotary cylinder 9
The second rotating cylinder 9 is biased so that the outer circumferential surface on the side 180° opposite to the sliding groove 16a of the first rotating cylinder 16 contacts the inner peripheral surface on the side 180° opposite to the sliding groove 16a of the first rotating cylinder 16, as shown in FIG. First rotary cylinder 1
6, and the top of the sliding protrusion 15 is inserted into the cutout relief part 16.
The top of the sliding protrusion 15 is inserted into the key groove 16a of the first rotary cylinder 16 so as to pass through the inside of the sliding protrusion 15. Subsequently,
When the 21st lens group holding cylinder 7 is attached to the rectilinear recoil cylinder 4 with the machine screw 8, the rotation center of the first rotation cylinder 90 and the rotation center of the first rotation cylinder 16 coincide, and the sliding protrusion 15 Fourth
As shown in the figure, it is deeply inserted into the sliding groove 16a.

Next, the engagement width of the sliding protrusion 15 is adjusted by rotating the small screw 17, so that there is no play between the sliding groove 16a and the sliding protrusion 15, and the sliding protrusion 15 slides smoothly. adjusted so that

Next, the first lens frame 10 supporting the lens group L1 is screwed into the linear inner cylinder 11 via the adjustment ring 14 and fixed. At this time, an adjustment ring 14 of an appropriate width is used so that the air distance between the first moving lens group L2 and the second moving lens group L2 becomes a predetermined reference distance.

In some examples of the first movable l/lens group L1, after the adjustment is completed, the bayonet member 1 is fixed to the right end of the fixed lens barrel 2, and then
The machine screw 18 is loosened so that the first rotary cylinder 16 can freely rotate relative to the intermediate revoid cylinder 6, and the intermediate revoid cylinder 6 is rotated. At that time, only the intermediate helicoid tube 6 is slightly rotated without rotating the first rotating tube 16, and the first moving 1/lens group L1 and the second moving 1/lens group L2 are integrated in the optical axis direction. , and use a collimator to focus at infinity.

When this banking is completed, loosen the machine screw 21, align the infinity symbol of the distance scale of the distance scale ring 20 with the index of the fixed lens barrel, and fix the distance scale ring 20 again with the machine screw 21. Next, the distance adjustment operation ring 22 and the tightening ring 19 are attached to complete the assembly and adjustment.

Since the embodiment shown in FIG. 1 is constructed as described above, when the distance adjustment operation ring 22 is rotated clockwise (in the direction of arrow R) in FIG.
and the intermediate helicoid tube 6 are integrated together in the clockwise direction (
(direction of arrow R). With this rotation, the intermediate helicoid barrel 6 moves to the left in FIG. 1 while rotating according to the lead of the female recoid screw 2a of the fixed lens barrel 2.

At this time, since the rotation of the straight helicoid tube 4 is restrained by the straight travel guide key 5, the male helicoid screw 4a
The intermediate helicoid f#i6 moves relative to the left according to the lead of the intermediate helicoid f#i6. Due to this relative movement of the rectilinear helicoid tube 4, the 21st/lens group holding tube 7 moves to the second 1/lens group L.
2, the 21st/lens group holding cylinder 7
The second rotary cylinder 9 screwed into the male helicoid screw 7a also moves to the left, and the first movement 1/lens group changes to the first movement 1/
move it to the left together with lens L2.

On the other hand, when the distance adjustment operation ring 22 rotates clockwise in FIG. 3, the first rotary cylinder 16 rotates clockwise together with the distance scale ring 19 and the intermediate helicoid cylinder 6. This first rotating cylinder 1
6, the sliding protrusion 1 engages with the sliding groove 16a.
5 rotates clockwise, the first rotary barrel 9 rotates according to the lead of the male helicoid screw 7a and further moves relative to the left with respect to the 21st/lens group holding barrel 7. Since the straight-moving inner cylinder 11 that is linked to the movement of the first rotating cylinder 9 is only restricted in rotation by the straight-moving key 12, the second rotating cylinder 9
The straight inner cylinder 11 moves to the left in accordance with the movement of the first group 1.
The / lens frame 10 is moved relative to the left with respect to the 21st / lens group holding cylinder 7. Therefore, the first movable lens group L1 and the second movable lens group L2 both move to the left while increasing the air distance l between them, and distance adjustment can be performed to the macro region without worsening aberrations.

In this relative movement in the optical axis direction between the linear inner cylinder 11 and the 21st/lens group holding cylinder 7, since the male helicoid screw 7b has a large lead, if the sliding protrusion 15 and the sliding groove 16 a
If there is play between the two, the amount of relative movement will be distorted, and this will adversely affect aberration correction. Again, sliding groove 16
If the width of a is machined into a chill bar shape so that the left end and right end are different, adjust the width of the sliding key 15 with the countersunk head machine screw 17 to engage it with the keyway 16a. Also, keyway 16
This may cause backlash in the wide portion of a, aggravating the 1/lens aberration, or the sliding key 15 may not move smoothly, making it impossible to accurately and smoothly adjust the distance.

However, like the rotary outer cylinder 16 of this embodiment, the sliding protrusion 15
passes through the notch relief part 1.6C and slides into the sliding groove 16a.
There is no need to cut open one end of the sliding groove j6a to the left end of the rotary outer cylinder 16. Therefore,
Both ends of the sliding groove 16a are closed, and when machining the sliding groove 16a, the rotary outer cylinder 16 may be deformed.
The width of the sliding groove 16a does not vary depending on the position.

In the above embodiment, the notch series] 6'C is the fifth
As shown in the figure, a circular arc shape is provided on a part of the inner circumferential surface of the first rotary cylinder 16, but this cutout relief part 16C is machined on the entire inner circumference of the first rotary cylinder 16, and the sliding groove 1. ．． It may be formed into a cylindrical shape reaching one end of 6a. In the above embodiment, the first
A gap S is provided between the rotary cylinder 16 and the second rotary cylinder 9, and the second
The rotary cylinder 9 is configured to be eccentrically inserted into the first rotary cylinder 16. However, by providing the notch relief part 160, the gap S can be made into a trench, and the second
The rotary cylinder 9 is inserted into the first rotary cylinder 16, and at that time, the protrusion height of the sliding protrusion 15 is lowered so that the sliding protrusion 15 passes through the notch relief part 16c and forms the sliding groove 16a. They may be configured to engage with each other.

Furthermore, in the embodiment shown in FIG. 1, the intermediate helicoid tube 6 and the first rotary tube 16 are connected and fixed with a machine screw 18 so that the rotation can be adjusted in order to take out the back of the lens. has been done. However, the first rotary cylinder 16 may be formed integrally with the intermediate helicoid cylinder 6 as long as the connection between the straight-moving helicoid cylinder 4 and the 21st/lens group holding cylinder 7 is configured to be rotationally adjustable.

Further, although the sliding protrusion 15 in the above embodiment is formed as a pair with the second rotating barrel 9, the bottle-shaped sliding protrusion 15 is connected to the second rotating barrel 9.
By crimping +J and forming the sliding groove 16a into a curved groove cam, the movement of the eleventh men's group L1 can be made inconstant.

〔Effect of the invention〕

As described above, according to the present invention, even if the sliding protrusion is formed integrally with the second rotary cylinder, and both ends of the sliding groove that engages with the sliding protrusion are formed with closed, the inside of the notch relief part remains. Since the sliding protrusion and the sliding groove can be precisely aligned through the lens, the photographing 1/lens lens barrel can be made lightweight and compact, and 1/lens movement such as focus adjustment can be performed accurately and smoothly. can. Furthermore, since the structure is simple and assembly is easy, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view showing one embodiment of the present invention, and FIG.
The figure is a cross-sectional view taken along the line A-A in Figure 1, Figure 3 is a cross-sectional view taken along the line B-B in Figure 1, Figure 4 is an enlarged cross-sectional view of a part of the C cross-section in Figure 1, and Figure 5 is a cross-sectional view taken along the line B-B in Figure 1. Fig. 1 is a perspective view of the first rotating cylinder that can be used in the embodiment; Fig. 6 shows the eccentric state of the first rotating cylinder and the second rotating cylinder when the sliding key of Fig. 1 is inserted into the keyway. It is an explanatory diagram. [Explanation of symbols of main parts] 2... Fixed lens barrel, 4... Straight helicoid tube 6... Intermediate helicoid tube. 7...Second lens group holding tube. 9... Second rotating cylinder (cylindrical member). 10... 1st group 1/lens frame, 15... Sliding protrusion. 16... First rotating cylinder (cylindrical member). 16a...Sliding groove, 16C...Notch relief part. 22・Distance adjustment operation member. L, . . . first moving lens group. L2/2nd movement 1/ns group Applicant: Nippon Kogaku Kogyo Co., Ltd. Agent Takao Watanabe Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Of a pair of cylindrical members provided so that one can move relative to the other inside the optical axis of the lens, a sliding protrusion is integrally formed on the cylindrical surface of one of the cylindrical members. a sliding groove capable of engaging with the sliding protrusion is formed in the other cylindrical member, and a notch relief portion communicating with the sliding groove is formed in one end surface of the other cylindrical member, and the pair of cylindrical members A photographic lens barrel characterized in that the sliding protrusion passes through the notch relief portion and engages with the sliding groove when the members are assembled. (2) The pair of cylindrical members include a first rotating barrel (16) and a second rotating barrel (16) that are both rotatable around the optical axis of the photographing lens.
9), a predetermined gap (S) is provided between the inner circumferential surface of the first rotating tube (16) and the outer circumferential surface of the second rotating tube (9), and corresponds to the gap (S). The second rotating cylinder (
9) is inserted eccentrically with respect to the first rotating barrel (16), the top of the sliding protrusion (15) protruding from the second rotating barrel (9) is inserted into the first rotating barrel (16). Claim 1, characterized in that the tube (16) is configured to pass through the notch escape portion (16c) formed in the tube (16) and engage with the sliding groove (16a). Shooting 1/lens lens barrel as described.