JPS5932970Y2 - Focal length display device for zoom interchangeable lenses - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a display device that can reliably display the focal length of a zoom type interchangeable lens.

BACKGROUND ART Various types of interchangeable lenses for cameras have been proposed in the past, in which focusing (ordinary distance adjustment) is performed by rotating an operating ring, and zooming (focal length adjustment) is performed by moving back and forth in the optical axis direction.

In order to read focusing and zooming in this type of lens, generally, as shown in FIG. The normal distance is read according to the reference line displayed along the optical axis direction on the part, while the focal length is read from the focal length scale E on the reference line along the operation ring part A1. There is.

By the way, the lens group is normally incorporated inside the front end of the operation ring A, and is configured to always move in the optical axis direction during focusing or zooming. Therefore, when the control ring is rotated, the normal shooting distance can be checked by reading the distance number on the end A1 of the control ring, but the display state of the focal length changes even though the setting state remains the same. .

In other words, when operating the operating ring A to set an arbitrary focal length, if the end A1 takes the position shown by the two-dot chain line in Fig. 1, the focal length at that time is between the reference line and the two-dot chain line. The value indicated by the intersection point is the value indicated by the point of intersection.Assuming that the shooting distance at this time was in a short distance state, if the operating ring A is rotated and adjusted to an infinite distance position, the operating ring end A1 becomes a solid line state,
The point of intersection with the reference line is different from the previous one by an amount of .

To solve this problem, it would be better to have a focal length indicating member that moves together with the operation ring when it moves in the optical axis direction, but does not move in conjunction with it when the operation ring rotates. , which requires a complex and special coupling mechanism.

Therefore, this invention provides a display device that does not require a complicated connection mechanism and can accurately confirm the focal length using an existing mechanism.

Embodiments of this invention will be described below with reference to FIGS. 2 to 5.

In FIG. 2, Ll, L2. L3°L4 is the 1st. Second. Of the third and fourth lens groups, the second lens group L2 is fixed to the inner tube 6b of the fixed lens barrel 6 via the holding frame 7, the third lens group L1, the third lens group L3 and the fourth lens group The lens group L4 is movable with respect to the fixed lens barrel 6, as will be described later, and focusing can be performed by changing the relative spacing of the lens group L1 with respect to the second lens group L2, the third lens group L3, and the fourth lens group L4. Also, the first . third and fourth lens groups,
L3. Zooming is performed by changing the relative interval of L4.

The lens group L1 is integrally assembled inside the front end of the operating ring 1, and a male helicoid is provided on the outer peripheral surface of the inner ring 1b of the operating ring 1, and the inner ring 6b of the fixed lens barrel 6 has a male helicoid. It is screwed into a male helicoid 3 at the front end of the movable cylinder 2, which is slidably disposed on the outer ring 1a, and an annular protrusion 5 is provided at a position closer to the front of the inner surface of the outer ring 1a. has a notch in the scale range from infinity to short distance, and a pin 4 provided on a part of the outer periphery of the front end of the movable tube 2 is inserted into the notch so that both end surfaces of the protrusion 5 are in contact with the pin 4. By rotating the operating ring 1 clockwise or counterclockwise, the operating ring 1
The lune group L1, which is integrated with the helicoid 3, is moved forward and backward in the optical axis direction by the lead of the helicoid 3, and focusing is performed from infinity to short distances.If the operation ring 1 is moved in the optical axis direction, the lune group L1 moves back and forth in the optical axis direction. move as one.

In that case, the movable barrel 2 also moves in the optical axis direction along with the operating ring 1.

The second lens group L2 is fixed to the inner tube 6b of the fixed lens barrel 6 via the holding frame 7 (which passes through the slit provided in the movable tube 2) as described above, while the third lens group L3 And the fourth lens group L4 is assembled into holding frames 8a and 8b that are slidably inserted into the movable cylinder 2, and these holding frames 8a
, 8b penetrate straight grooves (not shown) provided in the inner tubes 6b of the movable tube 2 and the fixed lens barrel 6, and pass through the cam grooves (not shown) of the cam tube 9. ), and the cam cylinder 9 is interlocked with the movement of the operating ring 1, thereby causing the third. Fourth lens group L3. L4 moves in the optical axis direction and performs zooming together with the first lens group L1.

However, the above configuration is no different from the conventional one.

By the way, in this invention, there is a pin 1 on the rear outer surface of the movable cylinder 2.
0 is implanted and as shown in FIG. retaining ring 1
2, the cam tube 9 is fitted into the inclined cam groove 14 of the cam tube 9, which is arranged so as not to move in the optical axis direction. A focal length scale 13 is engraved therein, and a guide groove 15 is provided in front of the other side of the inclined cam groove 14 and is perpendicular to the optical axis and has a length corresponding to the range of the focal length scale 13. A stop pin 16 attached to the inner tube 6b of the fixed lens barrel 6 is fitted therein.

Furthermore, the cam cylinder 9 has a third cylinder. Fourth lens group L3. L4 holding frame 8a.

As mentioned above, a curved cam groove is provided for actuating pins 17, 18 on 8b.

A window hole 19 is bored at the rear end of the outer barrel 6a of the fixed lens barrel 6 as shown in FIG. One of the scales can be read.

Next, to explain the operation, FIG. 4 shows each lens group Ll.
, L2. L3. L4 shows the state when the shortest focal length is set, and the pin 10 implanted in the movable barrel 2 is aligned with the linear groove 11 on the inner barrel 6b of the fixed lens barrel 6 and the cam barrel 9.
The stop pin 16 on the fixed lens barrel 6 is located at the left end of the guide groove 15 on the cam barrel 9, and at that time, the minimum focal length scale 7Qmm is located at the rear end of the inclined cam groove 14 in the window hole 19. is displayed.

In this state, if the operating ring 1 is operated in the direction of the optical axis as indicated by arrow A in FIG. It moves in the A direction together with the operating ring 1 while being guided by the linear groove 11 on the ring 6b.

At this time, since the inclined cam groove 14 of the cam barrel 9 rotatably fitted onto the inner barrel 6b of the fixed lens barrel 6 engages with the pin 10, the cam barrel 9 is rotated in conjunction with the operation of the operating ring 1. It is rotated and displaced in the direction of arrow B in FIG.

In this case, since the focal length scale 13 engraved on the rear edge of the cam barrel 9 has a correlation with the amount of rotation of the cam barrel 9,
The desired new focal length scale 13 is the outer barrel 6 of the fixed lens barrel 6.
It is displayed in a window hole 19 provided in a.

FIG. 5 shows that the pin 10 is connected to the inner barrel of the fixed lens barrel 6 in this way.
The stop pin 16 is located at the front end of the linear groove 11 of b and the inclined cam groove 14 of the cam tube 9, and the stop pin 16 is located at the right end of the guide groove 15, and the longest focal length scale 15Qmm is located at the window hole 19.
This shows the state in which it has become possible to read from.

Then, as the cam barrel 9 rotates, the third lens group L3 and the fourth lens group L4 are moved by their arcuate cam grooves, and are brought to the focal length position corresponding to the scale 13 displayed in the window hole 19. Of course.

On the other hand, when the operation ring 1 is rotated for focusing, the pin 10 on the movable barrel 2
Since the movable barrel 2 does not rotate because it is fitted into the linear groove 11 of the cam barrel 9, the focal length scale 13 displayed in the window hole 19 does not change and is integrated with the operating ring 1. Focusing is performed by moving forward and backward while rotating only the lens group L1.

As described above, in this invention, a pin is implanted on the outer surface of the rear end of the movable barrel that is screwed onto the operating ring and inserted into the inner barrel of the fixed lens barrel so as to slide in the optical axis direction. is fitted into the linear groove parallel to the optical axis direction provided in the inner tube of the fixed lens barrel and the inclined cam groove of the cam tube arranged so as to rotate only on the inner tube,
A focal length scale is engraved over the required range on the rear edge of the cam barrel, and this focal length scale is displayed in a window hole drilled in a part of the outer barrel of one of the fixed lens barrels. The cam barrel rotates in conjunction with the linear movement of the operating ring to perform zooming, and at the same time the focal length setting at that time is displayed in the window, and the setting scale changes as the operating ring rotates. The setting scale can always be read accurately, and existing components are used without the need for a special focal length display member separate from the operating ring.
The structure is simple and increases the utility value of interchangeable lenses.

[Brief explanation of drawings]

FIG. 1 is an end view of the lens body showing the display state of the conventional distance scale and focal length scale, FIG. 2 is a half-sectional view of an embodiment of this invention, and FIG. 3 is an external side view of the fixed lens barrel. Figure 4 is a partial exploded view showing the relationship between the movable barrel, cam barrel, and fixed lens barrel when the focal length is set to the minimum focal length, and Figure 5 is the same as Figure 4 when the focal length is set to the maximum focal length. Developed diagram. In the figure, 1... operating ring, 2... moving cylinder,
3...Female helicoid, 4...Pin, 5
...Protrusion, 6...Fixed lens barrel, 6a...
...The outer cylinder, 6b...The inner cylinder, 9...
...Cam tube, 10...Pin, 11...
・・Straight line groove, 13・・・・Focal length scale, 14・
...Incline cam groove, 15...Guiding groove,
19... Window hole.

Claims (1)

[Scope of utility model registration request] A pin 10 is implanted on the outer surface of the rear end of the movable barrel 2 which is screwed onto the operation ring 1 and fitted into the inner barrel 6b of the fixed lens barrel 6 so as to slide in the optical axis direction. The cam barrel 9 is fitted into a linear groove 11 parallel to the optical axis direction provided in the inner barrel 6b of the fixed lens barrel 6 and an inclined cam groove 14 of the cam barrel 9 disposed on the inner barrel 6b so as to rotate only. A focal length scale 13 is engraved over a required range on the rear edge, and one of the focal length scales 13 is displayed in a window hole 19 formed in a part of the outer tube 6a of the fixed lens barrel 6. Focal length display device for zoom type interchangeable lenses.