JPS59109008A - Zoom lens device - Google Patents

Abstract

PURPOSE:To make the structure simple and inexpensive by moving two pins fixed to lens barrels of zoom lens groups in the direction of an optical axis along sliding rods through cam grooves by the rotation of a zooming ratio adjusting plate. CONSTITUTION:By rotating a zooming ratio adjusting plate 19 in circumferential direction of a basic lens barrel 4 by an operating knob 22, projecting pins 7, 10 inserted into cam grooves 20, 21 move in the direction of an optical axis along sliding rods 11, 12. Then, a variater lens barrel 5 and a compensator lens barrel 8 to which pins 7, 10 are fixed move in the direction of the optical axis and the zooming ratio is adjusted according to the amount of rotation of the zooming ratio adjusting plate 19. When a focusing plate 16 is rotated by a pin 18, a projecting 3 inserted into a cam groove 17 receives force in the direction of the arrow B, a focusing lens 2 moves in the direction of the optical axis and the focusing is performed. Since the helicoid structure is not necessary, the structure is made simple and inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a zoom lens device suitable for television cameras, 8-frame cameras, etc. In particular, in order to reduce the price, it is possible to reduce the lens movement required for focus adjustment and zoom ratio switching. The present invention relates to a zoom lens device with a simplified configuration.

Conventional configuration and its problems In zoom lenses for television cameras and the like that have been put into practical use for a long time, in order to adjust the focus, a lens mirror is used to control the extension of the front group of the optical lens group. It is equipped with a so-called helicoid structure in which a screw provided on the outer periphery of the cylinder is used as a connection structure with the lens base, and the zoom ratio can be adjusted linearly in the optical axis direction to adjust the zoom ratio. Generally, a lens barrel has a structure consisting of a protruding pin provided on a lens barrel, and a zoom ratio adjustment ring provided with a cam groove that can be engaged with the protruding pin. In addition, since the lens group itself is circular in the above-mentioned movable lens structure, the manufacturing process necessarily involves processing a cylindrical member.

For this reason, thread cutting of the lens barrel for focus adjustment requires multiple threads of high precision screws, requiring a special machine tool and, in addition, requiring a considerable amount of machining time.

Therefore, the unit cost of parts for the focus adjustment structure in the conventional zoom lens device is high, and there is still a problem that mass production is poor and the cost of the zoom lens device becomes high.

On the other hand, the zoom lens ratio adjustment structure also requires machining of a cylindrical member, requiring high-precision machine tools and long machining times.Furthermore, during assembly, the zoom ratio adjustment lens is mounted inside the cylindrical adjustment ring. This was a cumbersome task.

Therefore, like the focus adjustment structure described above, the zoom ratio adjustment structure in the conventional zoom lens device also has the problems of high component costs, poor mass production, and making the zoom lens device expensive.

OBJECTS OF THE INVENTION An object of the present invention is to solve the problems that conventional zoom lens devices had because they used a helicoid configuration and the problems that they had because they used a cylindrical member. It is an object of the present invention to provide a simple zoom lens device having a lens drive means for focus adjustment and zoom ratio adjustment that is extremely simple in structure and easy to assemble.

Structure of the Invention A zoom lens device according to the present invention includes: a cylindrical first accommodating portion that accommodates a focusing lens barrel that performs focus adjustment; and a variator that is coaxial with the first accommodating portion and adjusts a zoom ratio. a basic lens barrel having a semi-cylindrical second accommodating portion for accommodating a lens barrel and a compensator lens barrel;
a long groove along the optical axis provided in the first accommodating portion and a bearing on the inner circumferential surface; a first protruding pin fixed to the focusing lens barrel via the long groove; , a second lens fixed to the compensator lens barrel. A third protruding pin and a sliding member for holding the two lens barrels provided in the second housing part for adjusting the zoom ratio in the second housing part so as to be movable in the optical axis direction. a rod, a cam groove into which the first protruding pin is fitted, an arcuate focusing plate having an externally operated configuration, a cam groove into which the second and third projecting pins are fitted, and an externally operated focusing plate; The lens moving device includes an arcuate zoom ratio adjusting plate having an operating configuration of:

DESCRIPTION OF EMBODIMENTS FIG. 1 is an exploded perspective view of essential parts showing an embodiment of a zoom lens device according to the present invention.

In the figure, 1 is a focusing lens 2. It shows a focusing lens barrel with a first protruding pin 3 secured by a screw arrangement or the like. Reference numeral 4 denotes a basic lens barrel, and as is clear from the drawing, there is a cylindrical first accommodating portion 4a that accommodates the above-mentioned focusing lens barrel 1 so as to be movable in the direction of its optical axis. It has a semi-cylindrical second accommodating portion 4b that accommodates a zoom ratio adjustment structure. 5 is
A variator lens barrel 8 with a second protruding pin 7 secured by a variator lens 6 for adjusting the zoom ratio, for example a screw arrangement, is connected to a compensator lens 9 for adjusting the zoom ratio, for example a screw arrangement. A compensator lens barrel is shown having a third protruding pin 10 fixed by the lens barrel 5, and each lens barrel 6, 8 is inserted into the second accommodating portion 4b of the basic barrel 4 described above. , 8 share a common optical axis and are accommodated via sliding rods 11, 12, and 13 so as to be movable in the direction of the optical axis. 14 is a long groove provided in the first accommodating part 4a of the basic lens barrel 4 and through which the first protruding pin 3 is passed; 15 is also provided in the inner circumferential surface of the first accommodating part 4a. The figure shows a bearing that reduces the torque required to move the focusing lens barrel 1 in the optical axis direction by coming into contact with the outer peripheral surface of the focusing lens barrel 1 described above. 16 has a cam groove 17 for focus adjustment into which the first protruding pin 3 that protrudes outward from the long groove 14 is inserted, and an operating knob 18 that can be operated from the outside.
A focusing plate 19 is rotatably provided with respect to the basic lens barrel 4, and a second lens 19 is fixed to the variator lens barrel 6 and the compensator lens barrel 8, respectively.
It has a cam groove 20.21 for adjusting the zoom ratio into which the third protruding pin 10 is inserted, and an operation knob 22 that can be operated from the outside, and is rotatably provided with respect to the base lens barrel 4. A zoom ratio adjustment plate is shown.

Reference numeral 23 designates a relay lens barrel that is combined with the basic lens barrel including the various lens barrels 1.5.8 described above to form the optical system of the zoom lens device according to the present invention.

The zoom lens device according to the present invention has the above-described configuration, and in the illustrated configuration, each lens barrel and adjustment plate are manufactured as follows.

First, focus adjustment lens 2. Variator lens 6, compensator lens 9. Lens barrels 1, 5, 8, and 23 for holding the relay lens barrel are formed using metal or resin.

The basic lens barrel 4 is formed from a resin material using, for example, an aluminum die-casting method in which molten alkali is poured into a predetermined mold, or an injection molding method, that is, a method that is extremely effective in mass production. First, the rough shape is manufactured, and then the focusing lens 2. Each lens barrel 1.5.8 is connected to the first and second housing portions 4a, so that the optical axes of the variator lenses 6, etc. all coincide with each other.
In order to accurately store it in the storage section 4b, it is completed by boring in the storage section.

Also, the focus adjustment plate 16. The zoom ratio adjustment plate 19 is different in shape from the conventional one and has an arc shape, so for example, the cam groove 17 for focus adjustment or the cam groove 20, 21 for zoom ratio adjustment is formed on a flat metal plate with a press metal. It is completed by punching using a method such as a mold or wire cutting, and then forming it into the shape shown in the figure by press working.

On the other hand, the zoom lens device can be completed by appropriately combining the illustrated components including the components manufactured as described above. That is, the first lens barrel 4 of the basic lens barrel 4 is made by an aluminum die-casting method or the like. A focusing lens barrel 1 is provided in the second housing portions 4a and 4b.
．． Variator lens barrel 6. The convencator mirror ms is accommodated via a bearing 15° sliding rod 11, 12, 13, a relay lens barrel 23 is attached, and a focusing plate 16. This can be completed by attaching the zoom ratio adjustment plate 19.

Note that when the focus adjustment plate 16 and the zoom ratio adjustment plate 19 are attached, the respective cam grooves 17. , 20.21 is fixed to each lens barrel 1.5.9, for example by a screw arrangement. Second. A third protruding pin 3,7°1o is inserted. That is, each protruding pin has the above-mentioned cam grooves 17, 20 .
Needless to say, it is fixed to each lens barrel via 21. Further, although not shown, when the basic lens barrel 4 and the relay lens barrel 23 are combined, a diaphragm configuration is usually formed between them.

Now, regarding the focus adjustment operation in one embodiment of the zoom lens according to the present invention, which is completed as described above, force is supplied from the outside to the operation knob 8 provided on the focus adjustment plate 16, and the focus is adjusted. This is done by rotating the adjusting plate 16 in the direction indicated by the arrow, which is the circumferential direction of the basic lens barrel 4.

This is because when the focusing plate 16 rotates, the cam groove 17
The rotational force will be transmitted to the protruding pin 3 fitted into the base lens barrel 4. On the other hand, as is clear from the drawing, the protruding pin 3 passes through the long groove 14 of the base lens barrel 4. As a result of the rotational force being supplied through the cam groove 17 as described above, a force is supplied in one direction of the arrow, and as a result, it is moved in the same direction.

LkyjZ, the protruding pin 3 is in the cam groove 17 mentioned above.
゜ Needless to describe in detail, the focusing lens barrel fixed through the long groove 14 moves in the direction of arrow B by moving the protruding pin 3 in the direction of arrow B due to the rotation of the focusing plate 16 in the direction of arrow B. Therefore, it will be moved to . By the way, regarding the moving direction of the focusing lens barrel 1 mentioned above,
Since the same direction of the arrow is along the optical axis of each lens with which the long grooves 14 coincide, it goes without saying that the direction is along the optical axis. It is determined by appropriately controlling the amount of rotation of the adjustment plate 16 using the operation knob 18.

Furthermore, if the moving operation of the focusing lens barrel 1 itself is configured to move only by the first protruding pin 3 and the cam groove 17, it would be impossible to put it into practical use due to rattling and friction. Since the housing 4a of the basic lens barrel 4 is equipped with a bearing 15 that comes into contact with the outer peripheral surface of the focusing lens barrel 1, the movement is extremely smooth. As with the recoid configuration, there are no problems in practical application; on the contrary, the reduction in the torque required for movement by the bearings 16 results in an advantageous movement movement, which allows for the miniaturization of the drive source, for example when forming an autofocus system. ing.

It should be noted that while the focusing lens barrel 1 is moving, the operation of the protruding pin s itself is controlled by the cam groove 17. Needless to say, the movement is sliding within the long groove 14.

On the other hand, the zoom ratio adjustment operation in the illustrated embodiment is similar to the focus adjustment operation described above.

That is, by rotating the zoom ratio adjusting plate 19 having the cam groove 20.21 in the circumferential direction of the basic lens barrel 4 using the operating knob 22, the second zoom ratio adjusting plate 19 having the cam groove 20.21 is inserted into the cam groove 20.21. The zoom ratio adjustment plate 19 is attached to the third protruding pin 7.10.
This is done by transmitting zero rotational force.

This is because of the second point above. Third protruding pin 7.10c, variator lens i cylinder 6. It is fixed to the compensator lens barrel 8, and the lens barrel 5°8 is connected to the basic lens barrel 4.
Since the slide rods 11, 12, and 13 are held so that they can only move linearly in the direction of the optical axis, rotational force is transmitted to the protruding pins 7, 10 through the cam grooves 20 and 21, as described above. If so, each lens barrel 5, 8 will be
This means that it will move in the optical axis direction.

It is clear that the amount of movement of the lens barrels 6 and 8 for adjusting the zoom ratio is appropriately controlled by the amount of rotation of the zoom ratio adjustment plate 19 by the operation knob 22.

Also, although it was not mentioned in the previous explanation of the focus adjustment plate 16,
The operation knobs 18 and 22, including the zoom ratio adjustment plate 19, have a concave-convex configuration similar to a conventional focus adjustment ring or a zoom ratio adjustment ring, that is, a configuration that allows manual operation. It goes without saying that any configuration can be adopted as the operating configuration for each arc-shaped adjustment plate.

FIG. 2 is an exploded perspective view showing an example of a case where the zoom lens according to the present invention shown in FIG. 1 is combined with an automatic focusing system, which has become particularly practical in recent years.

In the drawings, the same numbers as those in Fig. 1 indicate the same parts; 24
26 is a serrated portion provided on the focus adjustment plate 16 for rotational operation; 26 is a gear that meshes with the serration portion 24 and transmits the driving force of the motor 26, which is a drive source, to the focus adjustment plate 16; 2 has a conductor pattern 27a on a surface not shown in the drawing, and a position detector 28 attached to the focusing plate 16 is fixed to the basic lens barrel 4 and comes into contact with the above-mentioned conductor pattern 27a. The contact piece is shown.

Although it is unnecessary to explain in detail, the position detector 2 is
Since the contact piece 28 and the conductor pattern 27a are connected to each other by being attached to the focus adjustment plate 16, the contact state between the contact piece 28 and the conductor pattern 27a is controlled by outputting a setting position signal of the focus adjustment lens barrel 1, which is essential for the automatic focusing system. Therefore, the position detector 27
．． The contact piece 28 constitutes an electrical lens position detection device.

As is clear from FIG. 2, the zoom lens device according to the present invention has a structure for moving the lens, which is different from the conventional device's helicoid structure based on a 0-circumference cylinder shape, as described above. Focusing lens barrel 1 that performs rotational operation
Since the member for moving the position detector 27 and adjusting the focus is the focus adjustment plate 16 formed in an arc shape, the position detector 27 can be mounted very easily on the back side of the focus adjustment plate 16, unlike in the case of a cylindrical shape. This can be done in the department.

Further, the contact point 28 can also be easily fixed to the basic lens barrel 4 through the screw hole 28a. Furthermore, in the zoom lens device according to the present invention, since the focusing lens barrel 1 is housed in the accommodating portion 4a of the basic lens barrel 4 via the bearing 16, the drive characteristics by the motor 26 are also excellent. In other words, since the driving torque required for focus adjustment is reduced, the focusing lens barrel 1 can start and stop moving with great accuracy. In addition, it goes without saying that the motor itself can be made smaller.

Although not explained, the motor 26 may be fixed to the base barrel 4 or to a fixed part other than the base barrel 4, and the contact piece 28 may be fixed to a part other than the base barrel 4. Needless to say, it may be fixed to a fixed part.

Effects of the Invention The zoom lens device according to the present invention has a bearing in the arcuate member accommodating portion as a lens movement structure necessary for focus adjustment, so a helicoid structure is not required, and unlike the conventional device, There is no need to use high-precision machine tools to perform operations that are not suitable for mass production, and therefore the unit cost of parts can be reduced and the driving torque can be extremely small.

Further, the zoom lens device according to the present invention has a structure including a cam groove of an arc-shaped member, a protruding pin of a lens barrel, and a sliding rod as a lens movement structure necessary for adjusting the zoom ratio, and a housing portion with such a structure. Since the zoom ratio adjustment structure is formed in a semi-cylindrical shape, manufacturing of the zoom ratio adjustment structure including machining of the members is extremely simple, and the unit cost of the zoom ratio adjustment structure can be made low.

Seventh, the present invention has the advantage of being able to provide an inexpensive zoom lens device that has a simple manufacturing process and is highly suitable for mass production. In particular, when used in an automatic focusing system, the present invention is compact,
This has the effect of providing a lightweight zoom lens device.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of essential parts showing an embodiment of a zoom lens device according to the present invention, and FIG. 2 is an exploded perspective view showing an example of a case where the embodiment shown in FIG. 1 is combined with an automatic focusing system. be. 1... Focusing lens barrel, 3... Protruding pin, 4... Basic lens barrel, 6... Variator lens barrel, 8... ...Compensator lens barrel, 7, 10...Protrusion pin, 11.1
2.13...Sliding rod, 14...Long groove, 1
6... Bearing, 16... Focus adjustment plate, 17, 20.21... Cam groove, 19... River...
・Zoom ratio adjustment plate, 18.22... operation knob. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2

Claims (1)

[Claims] A first accommodating part that accommodates a focusing lens barrel for performing focus adjustment, and a semi-cylindrical second accommodating part that is coaxial with the accommodating part and accommodates a variator lens barrel and a convencator lens barrel that adjust the zoom ratio. a basic lens barrel having two accommodating parts; a long groove along the optical axis of each lens barrel provided in the first accommodating part; and a base lens barrel provided in the inner circumferential surface of the first accommodating part for adjusting the focus. a bearing that comes into contact with the outer peripheral surface of the lens barrel;
A first projecting pin is fixed to the focusing lens barrel through the long groove, and a second projecting pin is fixed to the variator lens barrel and the convencator lens barrel. a third protruding pin; and a sliding member provided in the second accommodating part and holding the variator lens barrel and the compensator lens barrel in the second accommodating part so as to be movable in the optical axis direction thereof; a rod, a first cam groove into which the first protruding pin is inserted, and an operation knob that can be operated from the outside;
an arcuate focusing plate capable of rotating the basic lens barrel in the circumferential direction; and the second. The second pin into which the third protruding pin is inserted. A zoom lens device comprising: an arcuate zoom ratio adjustment plate having an external operation structure such as a third cam groove and an operation knob, and capable of rotating the basic lens barrel in a circumferential direction.