JPH01288807A - Scale adjusting method for lens barrel - Google Patents

Abstract

PURPOSE:To facilitate the assembly, and also, to simplify the structure of a lens barrel by adjusting a lens holding frame to a prescribed position against a fixed cylinder, and thereafter, allowing it to correspond to its lens position and fixing a scale of an adjusting ring. CONSTITUTION:An adjusting ring 2 having an adjusting scale 9 is provided so as to be turnable against a fixed cylinder 2, and a lens holding frame 6 is provided so as to be movable in the optical axis direction against the fixed cylinder 1. By turning this adjusting ring 2, a position of the lens holding frame 6 can be adjusted in accordance with the turning quantity. In this state, at the time of assembly of a lens barrel, the adjusting ring 2 and the lens holding frame 6 are assembled to the fixed cylinder 1, the holding frame 6 is changed and adjusted to a prescribed position of the fixed cylinder 1, and thereafter, in accordance with its lens position, the adjusting scale 9 is fixed with an adhe sive agent. Therefore, a process for disconnecting the interlocking of the adjusting ring 2 and the holding frame 6 and allowing them to interlock again becomes unnecessary, and also, the structure is simplified.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for adjusting various scales such as a distance scale and a focal length scale in a lens barrel of a fixed focus lens or a zoom lens. It has an adjustment ring that is rotatably assembled to the fixed barrel and has an adjustment scale, and a lens holding frame that holds a lens that is movably assembled to the fixed barrel in the optical axis direction. , relates to a scale adjustment method for a lens barrel configured to change and adjust the position of the lens holding frame relative to the fixed barrel in accordance with the amount of rotation by rotating the adjustment ring.

[Conventional technology]

First, to briefly explain the structure of the main parts of this type of lens barrel based on Fig. 6, the distance ring (2), which is an example of an adjustment ring, is rotatable with respect to the fixed barrel (1). A distance ring interlocking key (4) is fixed to this distance ring (2) by a screw (3). A lens holding frame (6) that holds the lens grouping 1) is located inside the distance ring (2), and a male screw (
6a) is screwed into the female thread (7a) of the guide member (7), and the lens holding frame (6) is fitted with a screw (6b).
The distance ring driven member (5) is fixed by. A two-pronged engagement protrusion (5a) is protruded from the end of the distance ring driven member (5), and the distance ring interlocking key (4)
are engaged.

Therefore, when the distance ring (2) is rotated, the distance ring driven member (5) and the lens holding frame (6) are rotated together. However, since the lens holding frame (6) is screwed onto the guide member (7), the lens holding frame (6) moves in the optical axis (X) direction as the lens holding frame (6) rotates. Thus, the focus of the lens system is changed and adjusted.

In lens barrels with such a structure, conventionally, the distance scale (9a), which is an example of an adjustment scale, was engraved directly on the outer peripheral surface of the distance ring (2), or a plate with a distance scale was attached. However, in any case, the distance ring (2)
Since the distance ring (2) was previously marked with a distance scale (9a) before being assembled to the fixed tube (1), the following problems occurred.

That is, when the distance ring (2) and lens holding frame (6) are assembled to the fixed barrel (1), the optical axis (X
) It is necessary that the indicator attached to the fixed barrel (1) accurately indicates a predetermined distance on the distance scale (9a) on the distance ring (2) side in accordance with the position in the direction. Specifically, for example, if the lens holding frame (6) is in a position to focus at infinity, the fixed barrel (1
) The infinity of the distance scale (9a) must be located at the position of the index on the side. However, since the distance scale (9a) was attached to the distance ring (2) in advance, it was necessary to incorporate a mechanism between the distance ring (2) and the lens holding frame (6) to temporarily disconnect the two. did not become.

Regarding this point, in the conventional example shown in FIG.
) and the distance ring driven member (5) are separated, and by loosening the screw (6b) for fixing both, the distance ring (2
) and the lens holding frame (6). Therefore, in this example, after assembling the distance ring (2) and lens holding frame (6) to the fixed barrel (1), the screws (
6b) to disconnect the two, and first adjust the lens holding frame (6) to the infinity focusing position. Then, while holding the lens holding frame (6) in that position, rotate the distance ring (2) and set it so that the infinity of the distance scale (9a) is located at the index. The screw (6b) had to be tightened, making the assembly work very complicated. Furthermore, even if the lens holding frame (6) shifts slightly when tightening the screw (6b), accurate display will not be possible. However, it also had the disadvantage of becoming structurally complex.

[Problem to be solved by the invention]

The present invention has been made in view of these conventional drawbacks, and it is an object of the present invention to provide a new and useful scale adjustment method that can significantly reduce the number of steps for assembling a lens barrel and also simplify the structure itself. It is something to do.

[Means to solve the problem]

In order to achieve this purpose, the method for adjusting the scale of a lens barrel according to the present invention involves first assembling an adjustment ring and a lens holding frame to a fixed barrel, and adjusting the lens holding frame to a predetermined position with respect to the fixed barrel. After that, an adjustment scale is attached to the adjustment ring in a state corresponding to the position of the lens holding frame.

[For production]

In this way, the adjustment ring and lens holding frame assembled on the fixed tube are changed and adjusted while still being linked, and then the adjustment scale is attached, so it is necessary to disconnect the adjustment ring and lens holding frame each time. There is no need for the process of linking the two together again, and there is also no need for a mechanism to disconnect the two.

〔Example〕

First, the structure and operation of the lens barrel assembled by the method of the present invention will be explained based on FIG.
2) is rotatably assembled. This distance ring (2)
A distance ring interlocking key (4) is fixed by a screw (3) to the distance ring driven member (5), and this interlocking key (4) is attached to a bifurcated engagement protrusion (5a) protruding from the tip of the distance ring driven member (5). engaged.

Therefore, when the distance ring (2) is rotated, the distance ring driven member (5) and the first lens holding frame (6) integrally formed therewith are rotated. However, the 6th Runs holding frame (6
) is screwed into the female thread (7a) of the guide member (7), so the second lunz holding frame (
6), the lens holding frame (6) moves in the optical axis (X) direction.

As a result, the lens group (Ll) held by this lens holding frame (6) moves back and forth along the optical axis (X), and the focus of the lens system is changed and adjusted. At that time, the distance between the lens system and the subject is determined by the distance window (
This can be determined by looking at the distance scale (9a) through 8) and reading the scale corresponding to the index on the fixed cylinder (1) side.

Note that the rotation range of the distance ring (2) is determined by the distance ring stopper (12) fixed to the fixed frame (11) with the screw (10).
regulated by.

A zoom ring (13) is also rotatably attached to the fixed barrel (1), and this zoom! By rotating (13),
The cam vibe (14) is configured to rotate integrally. Two inclined cam grooves (14a) and (14b) are formed in this cam vibe (14), and cam followers (15) and (16) are installed in each cam groove (14a) and (14b), respectively. Insert position. Each cam follower (15), (16) is attached to the fixed frame (
They are also inserted into linear cam grooves (17a) and (17b) V formed in the fixed pipe (17) connected to 11).

One cam follower (15) is connected to the second lens group (
The other cam follower (16) is screwed to a second lens holding frame (18) that holds the lens L2), and the other cam follower (16) is screwed to a third lens holding frame (19) that holds the third lens group (L3). Therefore, when the zoom ring (13) is rotated, the cam vibe (14) is rotated, and each cam groove (14a), (
14b) cam 7 to 7 (15
).

(16) is also attempted to be rotated. However, each cam follower (15), (16) is connected to the fixed vibrator (1) at the same time.
7) Straight cam grooves (17a) and (17b) formed in
Since it is also engaged with each cam follower (15),
(16) and each lens holding frame (18) connected thereto,
(19) means to move back and forth along the optical axis (X). When the third lens holding frame (19) moves, the guide member (7) formed with the third lens holding frame (19)
The lens holding frame (6) screwed onto the guide member (7) also moves back and forth. In this way,
Zooming is performed on a lens system consisting of a lens group (Ll), a second lens group (L2), a third lens group (L3), and a fourth lens group (L4) held in a fixed holding frame (20). It is.

In the lens barrel having such a structure, the feature of the method of the present invention is that the distance scale (9a) is attached after the distance ring (2) is assembled. Therefore, as shown in Figure 2, a distance scale (9a) is displayed on the surface of a thin and flexible scale plate (9), and this scale plate (9) is different from the distance ring (2). It is considered to be a separate structure. The distance scale (9a) may be engraved or printed, and furthermore, a plurality of adhesive holes (9b) are formed on the scale plate (9), and adjustment indicators (9C) are displayed at predetermined locations. ing.

Next, we will explain the procedure for assembling the distance ring (2) and the second lens holding frame (6) using this scale plate (9). First, as shown in Fig. 3, the distance ring (2) is attached to the fixed cylinder. Before assembling to (1), place a scale plate (9) on the outer periphery of this distance ring (2).
Wrap it around and temporarily fix it in a rotatable state using a set tape (21) or the like. Thereafter, this distance ring (2) and the first lunium holding frame (6) are assembled to the fixed tube (1), and the distance ring (2) is rotated to move the second lunse holding frame (6) to infinity, for example. Adjust the focus position and use the screw (10) to set the distance ring stopper (12) in a predetermined position. Then, the distance scale (9a) appears in the distance window (8) of the fixed barrel (1), so rotate the scale plate (9) so that the adjustment index (9C) is aligned with the distance window as shown in Figure 4. (8) ff1(
Adjust to match 8a).

After adjustment, pour adhesive into the adhesive hole (9b) and adhere the scale plate (9) to the outer circumferential surface of the distance ring (2), then rotate the distance ring (2) and attach it to the other adhesive hole (9b). is the distance window (8)
When the adhesive is reached, pour adhesive into the other adhesive holes (9b) and adhere. After that, as shown in Figure 5, if the frame (8b) for the distance window is fixed, this frame (8b)
The indicator (8C) displayed in b) perfectly matches the distance scale (9a) at infinity, and the frame (8b) covers the adhesive hole (9b), so the aesthetic appearance is spoiled. Nor.

In this way, after assembling the distance ring (2) and the first lens holding frame (6) to the fixed cylinder (1), the distance scale (
Since the scale plate (9) with 9a) is to be glued,
Compared to the conventional method described at the beginning, the number of assembly steps can be reduced.

Furthermore, since there is no need for a mechanism to temporarily disconnect the distance ring (2) from the first lunus holding frame (6), the first lunth holding frame (6) and the second lunz holding frame (6) are Component (5)
It is also possible to integrally form both parts from the same material, thereby reducing the number of parts.

Although the scale plate (9) is used in the above embodiment, it is also possible to directly engrave the distance scale (9a) on the outer peripheral surface of the distance ring (2), for example. In short, all that is required for assembly is to attach the distance scale (9a) to the distance ring (2) later, and any specific method may be used. Further, although the distance ring (2) has been described as an example of the adjustment ring, it goes without saying that the present invention can also be applied to other systems such as the zoom ring (13).

〔Effect of the invention〕

As is clear from the above explanation, according to the method of the present invention,
The lens barrel can be easily assembled with a reduced number of steps, and the structure of the lens barrel can also be simplified.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for adjusting the scale of a lens barrel according to the present invention, in which FIG. 1 is a longitudinal sectional view of the lens barrel, FIG. 2 is a plan view of the scale plate, and FIG. 3 is a perspective view of the distance ring. , FIG. 4 is a plan view showing the relationship between the distance window and the distance plate, and FIG. 5 is a perspective view of the main parts of the fixed cylinder. FIG. 6 is a longitudinal sectional view of a lens barrel showing a conventional structure. (1)...Fixed barrel, (2)...Adjustment ring, (6)...Group/lens holding frame, (9a)...
Adjustment scale, (X), old...optical axis.

Claims (1)

[Claims] A fixed barrel, an adjustment ring rotatably assembled to the fixed barrel and having an adjustment scale, and a lens holding frame that holds a lens movably assembled to the fixed barrel in the optical axis direction. and a scale adjustment method for a lens barrel, wherein the adjustment ring is rotated to change and adjust the position of the lens holding frame relative to the fixed barrel in accordance with the amount of rotation. Then, after assembling the adjustment ring and the lens holding frame to the fixed barrel and adjusting the lens holding frame to a predetermined position with respect to the fixed barrel, the adjusting ring is attached in a state corresponding to the position of the lens holding frame. A method for adjusting a scale on a lens barrel, the method comprising: attaching an adjustment scale to the lens barrel.