JPS6046405B2 - Lens barrel with switching mechanism between tracking adjustment and macro photography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens barrel in which tracking adjustment and macro photography can be performed by moving the same master lens group or a part of the lens group forward and backward along the optical axis. In particular, this invention relates to a lens barrel having a mechanism for switching between tracking adjustment and macro photography, which allows the master lens group or some of its lens groups to reliably return to the once-adjusted tracking position after macro photography. .

In general, lenses for broadcast television, V) T, R) cameras, etc., display the subject image on the image receiving surface of the photo tube, and lenses for 16 mm cine cameras, etc., display the subject image on the film surface. It is well known that in order to form a sharp image, the master lens group or a part of the master lens group of the photographing lens system can be adjusted to advance or retreat along the optical axis, that is, tracking adjustment can be performed.

Furthermore, it is well known that the master lens group or a part of the master lens group, which is moved forward and backward along the optical axis by tracking adjustment, is similarly moved forward and backward along the optical axis during macro photography. By the way, when the lens barrel is configured so that the same lens group is moved and operated to perform tracking adjustment and macro photography as described above, normal photography is normally performed after tracking adjustment, and during the interval between normal photography. Generally, macro photography is performed as needed during macro photography, so when transitioning from macro photography to normal photography, it is necessary to quickly and accurately return the lens group to the appropriate tracking position that was initially adjusted. It is hoped that this will be obtained.

5 In response to the above request, the present applicant has filed a patent application, JP-A-51-10072, which states that after macro photography, the lens group that was moved during macro photography is automatically returned to the proper tracking position before movement. However, in view of the recent demand for lightweight and compact hand-held camera lenses, the reality is that a simpler and simpler configuration is desired.

Therefore, in response to the above-mentioned demands, the present invention has a tracking adjustment system that has a simpler configuration and is capable of reliably returning the lens group that was moved during macro photography after macro photography to the once adjusted tracking position. To provide a lens barrel having a mechanism for switching between macro photography and macro photography.

Hereinafter, a lens barrel having a mechanism for switching between tracking adjustment and macro photography according to the present invention will be described in detail with reference to embodiments shown in the accompanying drawings. FIG. 1 is a partial sectional view of a main part of an embodiment of a lens barrel having a switching mechanism between tracking adjustment and macro photography according to the present invention, and reference numeral 1 indicates a lens barrel fixedly connected to a camera body (not shown). Reference numeral 1 indicates a fixed barrel, and reference numeral 2 indicates a second fixed barrel which is fixedly connected to the first fixed barrel 1 by a mounting means such as a screw 3 and holds a focus lens or a zoom lens (not shown).

As shown in FIG. 1, this second fixed barrel 2 further includes a lens holding barrel 4 that holds the master lens group L of the photographic lens system, and has a multi-threaded male screw portion 4b formed on the outer periphery of the lens holding barrel 4. 2. The lens holding tube 4 is screwed into a multi-start female screw 2a formed on the inner circumference of the first and second fixed tubes 2, and the lens holding tube 4 is fitted in a circumferential direction formed on the peripheral walls of the first and second fixed tubes 1 and 2. Through the elongated holes 1a and 2b, which have a constant width that extends to the lens holding cylinder 4, that is, a width that allows the lens holding cylinder 4 to move forward and backward along the optical axis. The interlocking pin 4a on the lens holding barrel 4 protruding outside the first fixed barrel 1 is rotated in the circumferential direction around the optical axis by an operating means to be described later, thereby moving forward and backward along the optical axis. It is designed to be forced. Regarding the above-mentioned configuration, to describe the configuration particularly related to the present invention, in FIG.
20 indicates an operating means, 20 indicates a tracking position storage means,
The operating means 10 includes a ring member 11 and an operating knob 12.
, an engagement pin 13 and a spring 14.

The operating knob 12 is fitted into a guide groove 11a extending along the optical axis and formed in a ring member 11 rotatably fitted around the outer periphery of the first fixed barrel 1, as shown in FIG. As shown, the engagement pin 13 is attached so as to extend in the direction along the optical axis, and is always urged rightward in the figure by a spring 14. Furthermore, the ring member 11 includes
Interlocking pin 4 planted on the outer periphery of the lens holding cylinder 4
A linear keyway 11b is formed in the direction along the optical axis that engages with the keyway a. Therefore, by rotating the ring member 11 in the circumferential direction around the optical axis using the operating knob 12, the lens holding barrel A is rotated via the interlocking pin 4a, and the second fixed barrel is rotated. By screwing together with the flap 2, it can be moved forward and backward along the optical axis. Next, the tracking position storage means 20 will be described. This means 20 consists of a ring member 21 and a locking member 22, and the ring member 21 is connected to the first fixed cylinder 1 adjacent to the operating means 10
The flange surface corresponding to the operating means 10 is provided with a recessed engagement hole 21a that engages with the engagement pin 13. The locking member 22 is a screw member that is screwed into the ring member 21 so as to be movable toward the optical j-axis, and is a locking member that is tightened and fixed to the outer peripheral wall of the first fixed cylinder 1. It is a member. In addition, 23 in FIG. 1 indicates a stopper pin, which is anchored in a long hole 1C extending in the circumferential direction formed on the outer periphery of the first fixed cylinder 1, and serves to restrict the amount of rotation of the ring member 21. It is something. Further, 24 is a stopper that prevents the ring member 21 from moving in the direction along the optical axis. With the above configuration, the lens barrel shown in this embodiment can perform tracking adjustment, macro photography operation, and return to the adjusted tracking position after macro photography. That is, the tracking adjustment is carried out by rotating the operation knob 12 in the circumferential direction around the optical axis. Since they are integrally rotated and moved forward and backward along the optical axis, the master lens group L held by this lens holding cylinder 4 can be moved forward and backward along the optical axis.

At this time, the ring portion of the tracking position storage means 20 [
The member 21 is operated by the operating knob 12 due to the engaging pin 13 of the operating means 10 being engaged with the engaging hole 21a of the member 21.
It rotates integrally with the rotation of. Therefore, by locking the ring member 21 with the locking member 22 after the tracking adjustment is completed, the ring member 21 can memorize the tracking position as will be described later. Next, to describe the macro photography operation, macro photography is performed by first moving the operating knob 12 to the left in FIG. By rotating the master lens group L, the master lens group L can be moved forward and backward in the direction along the optical axis as described above.
This can be done by moving the operating knob 12 leftward in FIG. 1 against the spring 14, thereby disengaging the engagement pin 13 from the engagement hole 21a. After performing macro photography as described above, when performing normal photography again, the engagement pin 13 for fixing the operation knob 12 to the knob 12 is connected to the ring member 21.
This can be done by rotating the cover so that it engages with the engagement hole 21a.

That is, the ring member 21 stores the initially set and adjusted tracking position, and when the operating knob 12 is operated to maintain a constant positional relationship with the tracking position.
For example, the master lens group L that has been moved can be easily and reliably returned to its original tracking position. Next, another embodiment of the present invention will be described in detail with reference to FIG.

FIG. 2 is a partial sectional view showing the main part of another embodiment according to the present invention. In FIG. It is fixedly connected to a fixed tube 102 which is fixedly connected to a tube (not shown). In contrast to this fixed barrel 101, a lens holding barrel 104 that holds the master lens group L'' of the photographic lens system
is slidably installed inside the lens holding tube 104.
The interlocking pin 104a engages with a helical cam slot 105a formed in a cam ring 105 rotatably fitted on the outer periphery of the fixed barrel 101 through a linear keyway hole 101a along the optical axis of the fixed barrel 101. As will be described later, when the cam ring 105 is rotated, it moves forward and backward along the optical axis. The cam ring 105 is
A linear keyway 106a along the optical axis formed integrally with the operating ring 106 fitted on the outer periphery of the operating ring 106.
is rotated by engagement with the engagement pin 105b on the cam ring. Furthermore, in FIG. 2, reference numeral 107 indicates a tracking position memory ring, and the ring 107 is rotatably fitted on the outer circumference of the fixed cylinder 101.
Another fixed cylinder 1 fixedly connected to 01 with a screw 108
A locking screw 110 that is screwed into the optical axis 09 and moves back and forth toward the optical axis makes it unrotatable.
Furthermore, this tracking position memory ring 107 has a recessed engagement hole 107a in its right flange.
07a is engageable with an engagement pin 1r06b planted on the left flange portion of the operating ring 106. In addition, in Figure 2, 1
Reference numeral 11 denotes a stopper pin 1 that engages with a circumferential elongated hole 107b formed in the tracking position memory ring 107 and restricts the amount of rotation of the tracking position memory ring 107.
12 is a stopper that restricts the movement of the operating ring 106 to the left in the figure along the optical axis and the movement of 107 to the right in the figure; and 113 is a spring that urges the operating ring 106 to the left in the figure. and 114 is the lens holding tube 1
04 rattling prevention spring is shown. By configuring as described above, it is possible to obtain the same effects as those of the embodiments described above. In other words, the tracking adjustment
By rotating the operation ring 106 in the state shown in the figure, the lens holding cylinder 104 can be moved forward and backward along the optical axis by the cam ring 105 that rotates integrally with the operation ring 106. Ru. And this operation ring 10
Tracking position memory ring 107 along with rotation operation of 6
is the engagement pin 1 of the operating ring 106 in the engagement hole 107a.
06b), the tracking position is memorized and fixed by making it unrotatable with the locking screw 110. On the other hand, when performing macro photography, the operating ring 106 is moved to the right in the figure against the spring 113, and the engagement hole 107a is moved.
5 and the engagement pin 106b, the operation ring 106 can be rotated freely and the lens holding cylinder 104 can be moved forward and backward as described above, thereby enabling macro photography. After macro photography, the master lens group L'' can be returned to the original tracking position by rotating the operating ring 106 so that the O-engaging pin 106b engages with the engagement hole 107a again. As is clear from the above explanation, according to the present invention, the master lens group or a part of the master lens group whose position is adjusted by the tracking position adjustment is used to move the master lens group back and forth along the optical axis again. After macro photography, the camera can quickly and reliably return to the position where it was once adjusted, which is particularly advantageous when performing normal photography and macro photography without any interruption, and the structure is simple and compact. It can be effectively applied to handy cameras and the like.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing the main parts of one embodiment of a lens barrel having a switching mechanism between tracking adjustment and macro photography according to the present invention, and FIG. 2 is a partial sectional view showing the main parts of another embodiment. There is a cross-sectional view. DESCRIPTION OF SYMBOLS 1...First fixed barrel, 2...Second fixed barrel, 4...Lens holding barrel, 10...Operation means,
11... Ring member, 12... Operation knob, 13... Engagement pin, 14... Spring, 20... Tracking position memory member ,
21... Ring member, 22... Locking member, 101... Fixed tube, 104... Luns holding tube, 105... Cam ring, 106...
...Operating ring, operating means, 113... Spring, operating means, 107... Tracking position memory ring, tracking position memory member, 110.
...Lock screw, tracking position memory member.

Claims (1)

[Claims] 1. In a lens barrel in which a master lens group or a partial lens group thereof disposed in a fixed barrel can be moved forward and backward along an optical axis by operating an external operating member to perform tracking adjustment and macro photography, the above-mentioned A tracking position memory member 20 is provided which is in a fixed positional relationship with the operating member 10 and can be engaged through the engaging means 13 and is made immovable by the locking means 22. The member 10 and the tracking position memory member 20 are brought into an engaged state and moved together, and the locking means 22 locks the tracking position memory member 20 at a position corresponding to a desired tracking position. When photographing, the engagement between the operating member 10 and the tracking position storage member 20 can be released by operating the operating member 10 in a direction perpendicular to the direction in which the lens group is moved, and only the operating member 10 can be moved. A lens barrel having a switching mechanism between tracking adjustment and macro photography.