JPS61124911A - Zoom lens - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a zoom lens and to improve the operability and stability by bringing a driving wheel or gear into friction contact or engagement with the inner periphery of an annular member which is driven by an operation ring such as a zoom ring and a stop ring, and rotating the operation ring by a motor from inside a lens barrel. CONSTITUTION:A stop driving ring 56 is mounted on the inner peripheral surface of the external tube in the space between the internal flange part 11a of the external tube and a motor substrate 41, and its inner peripheral surface is brought into friction contact with the stop driving wheel 53. A pin 59 projected radially from a stop cam rotating tube 23 is fitted in the longitudinal groove of the stop ring 58, and the stop driving ring 56, stop ring 58, and stop cam rotating tube 23 are rotated associatively through pins 57 and 59. Therefore, when the stop driving motor 27 is rotated, the stop driving gear 53 is rotated through a pinion gear 55 and a stop driving wheel 54 rotating integrally with it rotates the stop driving ring 56 to rotate the stop cam rotating tube 23 through the stop ring 58 and pins 57 and 59, thereby adjusting the degree of opening of a stop 9.

Description

[Detailed Description of the Invention] [Industrial Application] The present invention relates to a zoom lens, and in particular to a zoom lens with a four-group configuration that is used attached to a television camera, etc., and is used for remote control of zooming or aperture adjustment, auto iris, etc. The present invention relates to a zoom lens suitable for performing.

[Prior art j] A zoom lens to which this invention is applied has a common optical axis in the lens barrel at the front (object side), as shown in Fig. 4, for example.
Focus lens 1. Variable magnification lens 2. Correction lens 3
．． It is a zoom lens with a four-group configuration in which relay lenses 4 and 4 are sequentially arranged.The relay lens 4 is mounted on a mount 8a.
A diaphragm S is attached to the relay lens frame, and an inner tube 10 and an outer tube 11 constituting the lens barrel are integrally fixed, and a cam is mounted between the two tubes. The cylinder 12 is rotatably held.

Further, a guide ball 13 is provided inside the inner tube 10 parallel to the optical axis.
and a pre-stop ball 14 is fixedly installed, and its guide pole 13
A hawk-shaped hole is formed on the opposite side edge of each frame by penetrating one side edge of the variable power lens frame 6 that holds the variable power lens 2 and the correction lens frame 7 that holds the correction lens 3. A pre-stopping ball 14 is inserted into the portion to hold the variable power lens 2 and the correction lens 3, which constitute the variable power system, respectively, so as to be slidable in the optical axis direction but not rotatable. Note that, in reality, there are two guide poles 13, and they guide the variable power lens frame 6 and the correction lens frame 7 separately.

The focus lens 1 is held in a focus lens frame 5 screwed into an inner cylinder 10 by a helicoid 1S, and by rotating a focus ring formed integrally with the frame 5, the focus lens 1 is aligned in the optical axis direction. The force movement is performed by moving to .

Also, by rotating the zoom ring 17 attached to the outer circumference of the outer cylinder 11, the cam cylinder 12 is rotated via the pin 18, and the sliding pieces 19, 20 fitted into the cam grooves are rotated.
Zooming is performed by moving the variable magnification lens 2 and the correction lens 3 in a predetermined relationship in the optical axis direction through the lens.

Further, by rotating the aperture ring 21 attached to the outer periphery of the outer cylinder 11, the aperture cam rotating cylinder 23 is rotated via the pin 22 to adjust the aperture opening degree.

FIG. 4 shows such a conventional zoom lens in which focusing, zooming, and aperture adjustment are performed by motors, and a focus lens driving motor 24 and a zooming motor are installed outside the outer barrel 11. 25 is attached, and an aperture drive motor 27 is attached to a fixed substrate 26 provided integrally with the relay lens frame 8, and each pinion gear 28, 29° 30 fixed to the rotation axis of each of these motors is connected to the focus ring 16. ．． Zoom ring 17. and ring gears 31, 32, and 33 formed on the outer periphery of the aperture ring 21, so that each ring can be individually rotated by each motor.

In order to protect these motors, gears, etc., the entire lens barrel is covered with a cover member 34.

[Problem that the invention seeks to solve]

However, such conventional motor-driven zoom lenses are used for focusing as described above.

The motors and gear mechanisms for zooming and aperture adjustment were all placed outside the lens barrel, which was then wrapped in a large cover, making it very large and heavy (especially since the center of gravity was at the front). (poor stability), making it difficult to attach and detach from the camera, and also resulting in poor appearance.

This invention solves these problems by eliminating the need to provide at least one of the zooming motor and the diaphragm drive motor or the aperture on the outer periphery of #1.
Designed to be smaller and lighter (center of gravity moved backwards to increase stability)
The purpose is to improve the appearance and operability.

[Means for solving problems]

Therefore, this invention focuses on the fact that the relay lens in a 4-group zoom lens has a considerably smaller diameter than the lens barrel that holds a large-diameter focus lens, etc., and that there is space around its outer periphery. A drive motor and a drive wheel or gear rotated by the motor are provided on the outside of the lens barrel, and the drive wheel or gear is moved together with an operating ring such as a zoom ring or an aperture ring attached to the outer periphery of the lens barrel. The problem described above is solved by bringing the annular member into frictional contact with or meshing with the inner periphery of the rotating annular member, and driving the annular member and the operating ring from inside the lens barrel by the motor through the driving wheel or gear. This is the solution.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In this embodiment, not only zooming and aperture adjustment but also focusing is performed by motor drive, and each drive motor and its drive force transmission mechanism are all housed within the lens barrel, replacing the conventional cover member. This is a completely unnecessary zoom lens.

Note that FIG. 1 is a vertical cross-sectional view mainly for explaining the zooming and aperture adjustment drive mechanisms, FIG. 2 is a vertical cross-sectional view mainly for explaining the focusing drive mechanisms, and FIG. 3 is a main part of each drive mechanism. FIG. 3 is a schematic cross-sectional view showing the arrangement relationship in the circumferential direction within the lens barrel, and portions that are not necessarily in the same cross section are shown in the same drawing for convenience of illustration.

In these figures, the same parts as in FIG. 4 are designated by the same reference numerals, and their explanation will be omitted. however.

The outer tube 11 extends slightly to the rear of the rear end of the relay lens frame 8, and is fitted into a mount 40 provided separately from the relay lens frame 8 and fixed with screws.

A motor board 41 is fixed between the rear inner periphery of this outer cylinder 11 and the outer periphery of the relay lens 4 in a direction perpendicular to the optical axis I.
A focus ring driving motor 24, a zooming motor 25.
and an aperture drive motor 27 are mounted parallel to the optical axis direction, and each motor is housed in a space surrounded by the outer tube 11, the relay lens frame 8, the mount 40, and the motor board 41.

First, although it is not related to this invention, the second
The focus lens drive mechanism will be explained with reference to the drawings.

One ring gear 42 is rotatably mounted on the outer periphery of the relay lens frame 8 via a pole bearing, and the small diameter gear portion 42. Focus lens drive motor 24
A pinion gear 43 fixedly attached to the rotating shaft is engaged.

The large diameter gear portion 42b of the ring gear 42 has an outer cylinder 11
A pair of pole drive gear nuts 44.4 having the same diameter (naturally the same number of teeth and the same pitch) are held between the inner flange portion 11a and the motor board 41 and prevented from moving in the optical axis direction.
5 are engaged.

In addition, in FIG. 3, the small diameter gear part 42a and the large diameter gear part 42b of this ring gear are shown in common.

Furthermore, a pair of poles 46 and 47 are slidably penetrated and supported along the optical axis direction by the inner plunge portions 10a and 10b of the interior 10, which together with the outer barrel 11 constitute a lens barrel.

As clearly shown in FIG. 3, the pair of poles 46 and 47 are disposed on substantially opposite sides in the circumferential direction (separated by approximately 180 degrees), and one pole 46 is located on the guide ball of the correction lens frame 7. The other pole 47 also serves as a pre-stopping pole for the variable power lens frame 6 and the correction lens frame 7.

Note that the guide pole 14 of the variable magnification lens frame 6 is separately provided close to the pole 45 as shown in FIG.
0 between the inner flange portions 10a and 10b.

The tip ends of the poles 46 and 47 are screwed and fixed to the focus lens frame 5, respectively, and the rear end portions extend rearward through the inner flange portion 11a of the outer tube 11 and the motor board 41, and form a male screw portion 46a.

47a, and each gear nut 44 mentioned above.
．． 45 into female threaded holes 44a, 45a.

Therefore, when the focus lens driving motor 24 is rotated, the ring gear 42 rotates via the pinion gear 43 as shown by arrow A in FIG. 46 rotate by the same angle in the same direction.

Since the gear nuts 45 and 46 are prevented from moving in the optical axis direction, their rotation causes the poles 46 and 47 to slide by the same amount as shown by arrow B in FIG. When moving the focus lens 1 in the optical axis direction via the lens frame 5, the focus lens frame 5 is connected to the fitting portion 10C of the inner cylinder 10.
5 and the poles 46 and 47 always move forward and backward by the same amount, so they move without being tilted with respect to the optical axis R.

In this way, by driving the motor 24, force pulling can be performed.

A focus ring 48, which is an operation ring for manual focusing, is rotatably mounted on the outer periphery of the outer cylinder 11. The ring gear 42 is rotated at an increased speed through the transmission train.

Therefore, by rotating this focus ring 48, the ring gear 42 is rotated, and the gear nuts 44 and 45 and the ball 46 are rotated in the same way as when driven by the motor 24.
．． 47. By moving the focus lens 1 in the optical axis direction via the focus lens frame 5, force focusing can be performed.

Next, referring mainly to FIG. 1, the zooming and aperture adjustment circumferential drive mechanism according to the present invention will be described.

A zoom drive gear 4 is rotatably supported between the inner flange part 10b of the inner cylinder 10 and the motor board 41 through the inner flange part 11a of the outer cylinder 11, and is connected to the rotating shaft of the zooming motor 25. It meshes with a fixed pinion gear 50.

A zoom drive wheel (friction wheel) 51 is fixed coaxially with the zoom drive gear 4, and the notch 1 of the inner cylinder 10
It is in frictional contact with the inner peripheral surface of the cam cylinder 12 through 0d.

Therefore, when the zooming motor 25 is rotated,
The zoom drive gear 4 rotates via the pinion gear 50, and the cam barrel 12 is rotated as shown by arrow C in FIG. 3 by the zoom drive wheel 51 that rotates together with it.

As a result, the sliding piece 19.2 in FIG.
Zooming is performed by sliding the variable power lens frame 6 and correction lens frame 7 along the balls 46, 47. can be done.

Further, a zoom ring 52, which is a manual operation ring for zooming, is directly fixed to the outer periphery of the cam barrel 12, and the cam barrel 12 can be manually rotated by this zoom ring 52 to perform zooming.

Therefore, in this case, the operating ring is the zoom ring 52.
The annular member that rotates in conjunction with this is a cam cylinder 12 for zooming.

Note that the cam cylinder 12 can be rotated easily.

It is preferable to support the inner cylinder 10 via a ball.

Next, the aperture adjustment drive mechanism will be explained.

An aperture drive gear 53 having an integral aperture drive shaft (friction wheel) 54 is rotatably supported between the inner flange portion 11a of the outer cylinder 11 and the motor board 41, and is connected to the rotation shaft of the aperture drive motor 27. It meshes with a fixed pinion gear 55.

An aperture drive ring 56 is rotatably mounted on the inner circumferential surface of the outer cylinder in this space via a ball bearing, and its inner circumferential surface is brought into frictional contact with the aperture drive shaft 53.

A pin 57 is implanted in this aperture drive ring 56, and the outer cylinder 11
The aperture ring 58 projects outward through an arcuate groove and is fitted into a vertical groove of an aperture ring 58, which is a manual aperture adjustment operation ring rotatably mounted on the outer peripheral surface of the outer cylinder 11.

Further, a pin 5 extending radially from the aperture cam rotating tube 23 is also fitted into the vertical groove of the aperture ring 58, and the aperture drive ring 56, the aperture ring 58, and the aperture cam rotating tube 23 are fitted into the vertical groove of the aperture ring 58.
3 and 5 rotate together through pins 5 and 5.

Therefore, when the aperture drive motor 27 is rotated, the aperture drive gear 53 rotates via the pinion gear 55, and the aperture drive shaft S4, which rotates together with the aperture drive gear 53, rotates the aperture drive ring 56 as indicated by the arrow in FIG. The opening of the aperture S is adjusted by rotating the aperture cam turner 23 in the same direction via the aperture ring 58 and pins 57 and 59.

The opening degree of the aperture 9 can also be adjusted by directly rotating the aperture ring 58 by hand or by rotating the aperture cam rotating cylinder 23 via the pin 5.

Therefore, in this case, the operating ring is the aperture ring 58, and the annular member that rotates together with it is the aperture drive ring 56.

Note that the zoom drive shaft 51 and the zoom drive gear 49. Aperture drive wheel 54 and aperture drive gear 5
It is preferable that the zoom drive shaft 51 or the aperture drive wheel 54 slips and idles during manual operation by friction coupling 3 and 3 respectively.

In addition, the zoom drive shaft 51 and the aperture drive wheel S3 are replaced with friction wheels and are made into gears, and are engaged with internal gears formed on at least a portion of the inner circumferential surface of the cam cylinder 12 and the inner circumferential surface of the aperture drive ring 56, respectively. Through the combined gear mechanism,
The cam cylinder 12 and the aperture drive ring 56 may be rotated.

As explained above, according to this embodiment, the motors for force shifting, zooming, and aperture adjustment, as well as their driving force transmission mechanisms, are all housed within the lens barrel, eliminating the need for a conventional cover at all. This allows the overall diameter to be approximately the same as a general zoom lens that can only be operated manually, making it compact, lightweight, and easy to operate.

It has good stability and appearance, and is easy to operate not only by motor but also by manual operation.

〔Effect of the invention〕

In the zoom lens according to the present invention, a drive motor and a drive wheel or gear rotated by the drive motor are arranged outside a relay lens frame in a lens barrel, and the drive wheel or gear can be operated like a zoom ring or an aperture ring. The ring is brought into frictional contact or engaged with the inner periphery of an annular member that moves together with the ring, and the operating ring is rotated by the motor inside the lens barrel, so that the entire operating ring drive mechanism is housed within the lens barrel. Compared to conventional zoom lenses of this type, the lens is significantly smaller and lighter (because no cover is required), and operability and stability are also improved.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view of a zoom lens showing an embodiment of the present invention. FIG. 2 is a schematic longitudinal cross-sectional view showing some different parts. FIG. 3 is a schematic cross-sectional view of the main part thereof. FIG. 4 is a schematic vertical sectional view showing an example of a conventional motor-driven zoom lens to which the present invention is applied. 1... Focus lens 2... Variable magnification lens 3.
...Correction lens 4...Relay lens 5...
・Focus lens frame 6...variable magnification lens frame 7...
・Correction lens frame 8...Relay lens frame S...
・Aperture 10...Inner tube 11...Outer tube 12・
...Cam tube 23...Aperture cam rotating tube 24.
...Focus lens drive motor 2S...Zooming motor 27...Aperture drive motor 40...Mount 41...Motor board 42
...Ring gear 44, 45...Gear nut 46
47...Ball 48...Focus ring 49...Zoom drive gear 51...Zoom drive wheel 52...Zoom ring 53...Aperture drive gear 5
4... Aperture drive wheel 56... Aperture drive ring 5
8... Aperture ring 1 Figure 1: Focus lens 25: Zoom lens 2: Variable magnification y-z 27: Aperture drive motor 3: Aperture ring 41. :4-Yukikari 4:Sv-v/zu
49: Zoom drive gear 8: Relay lens e
st: Zoom drive shaft 52: Zoom rig/g 9: III 10: Inner m S3: Su drive 4711: Outer cylinder 12; Cam cylinder S: Aperture drive shaft 23: Aperture cam rotation m 56: Aperture drive ring 58: Aperture sill Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A zoom lens in which a focus lens, a variable magnification lens, and a correction lens are each movably provided in the optical axis direction in front of a relay lens fixed to a mount side of a lens barrel, comprising: A drive motor and a drive wheel or gear rotated by the motor are provided on the outside of the relay lens frame that holds the relay lens, and the drive wheel or gear is mounted on the outer periphery of the lens barrel for operation. The annular member is brought into frictional contact with or meshes with the inner periphery of an annular member that rotates together with the ring, and the annular member and the operating ring are rotationally driven from inside the lens barrel by the motor via the drive wheel or gear. A zoom lens that is characterized by 2. Claims in which the annular member is a cam cylinder that rotates together with a zoom ring that is a zooming operation member and moves the variable power lens and the correction lens in the optical axis direction to perform zooming. The zoom lens described in item 1. 3. The zoom lens according to claim 1, wherein the annular member is an aperture drive ring that rotates in conjunction with an aperture ring for adjusting the aperture.