JP2021092678A - Lens device and imaging apparatus - Google Patents

Abstract

To provide a lens device which is advantageous in terms of the smooth movement of a lens group, even when an accessory is attached for instance.SOLUTION: The lens device includes a first cylindrical member which holds the lens group and in which a male screw is formed on the outer peripheral part, a second cylindrical member in which a female screw to be engaged with the male screw is formed on the inner peripheral part, an operation member which is fitted to the outside of the second cylindrical member and is rotatable around the shaft of the second cylindrical member, and a connection member which connects the first cylindrical member and the operation member and transmits the rotation of the operation member around the shaft to the first cylindrical member. In the second cylindrical member, a hole penetrating in a radial direction is formed in a part where the female screw is not formed. The connection member is inserted into the hole, to connect the first cylindrical member and the operation member.SELECTED DRAWING: Figure 2

Description

The present invention relates to a lens device and an imaging device.

As a lens device having an inner focus mechanism, a lens group that moves along the optical axis by a helicoid screw formed on the inner peripheral portion of the fixed cylinder, an operating ring provided on the outer peripheral portion of the fixed cylinder, and an operating ring and a lens. Those having a connecting member that connects the groups to each other are known. The lens group moves along the optical axis by rotating the operating ring around the optical axis.

In the lens device, when the lens group is moved by the rotation of the operation ring, an elongated hole is formed in the fixed cylinder in order to avoid interference between the connecting member and the fixed cylinder, and the connecting member is inserted into the elongated hole. The operation ring and the lens group are connected to each other.

FIG. 2 of Patent Document 1 discloses the positional relationship between the helicoid screw of the fixed cylinder, the lens group, the operating ring, and the connecting member described above. In Patent Document 1, the connecting member has a pin shape, is provided in a lens group, and engages with a guide hole of an operation ring. The fixed cylinder is formed with an elongated hole that penetrates the helicoid screw in order to avoid interference with the connecting member. Then, when an accessory such as a hood is attached to the tip of the fixed cylinder, the distortion transmitted to the helicoid screw is reduced by dividing the fixed cylinder in order to reduce the influence of the distortion of the helicoid screw on the operation of the focus mechanism. ing.

Japanese Unexamined Patent Publication No. 9-211303

In the lens barrel of Patent Document 1, when an accessory is fastened to an accessory fixing frame with a screw, the axial force (tightening force) of the screw reaches, for example, several tens to several hundreds of kgf, and the accessory fixing frame is deformed. Then, the gap between the accessory and the accessory fixing frame is filled, the deforming force to the accessory fixing frame is transmitted to the fixing cylinder, and the helicoid screw is distorted, which may affect the operation of the focus mechanism. Further, in the fixed cylinder, since the helicoid screw has a long hole for passing (inserting) the connecting member, the strength (rigidity) around the long hole is low, and the helicoid screw is easily distorted.
An object of the present invention is to provide a lens device that is advantageous in terms of smooth movement of a lens group even when an accessory is attached, for example.

In order to achieve the above object, in the lens device of the present invention, the first tubular member which holds the lens group and has a male screw formed on the outer peripheral portion and the female screw screwing with the male screw are inner peripheral portions. A second tubular member formed in the above, an operating member that fits on the outside of the second tubular member and can rotate around the axis of the second tubular member, the first tubular member, and the above. It has a connecting member that connects to the operating member and transmits the rotation of the operating member around the shaft to the first tubular member, and the second tubular member is formed with the female screw. A hole penetrating in the radial direction is formed in the portion not provided, and the connecting member is inserted into the hole to connect the first tubular member and the operating member.

According to the present invention, for example, it is possible to provide a lens device that is advantageous in terms of smooth movement of a lens group even when an accessory is attached.

Cross-sectional view of the lens barrel according to the first embodiment of the present invention. Detailed view of the lens barrel according to the first embodiment of the present invention. Detailed view of the lens barrel according to the second embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the lens barrel 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an overall view of the lens barrel in this embodiment.

The lens barrel 1 of this embodiment is a mechanism in which a moving cylinder (first tubular member) 2 having a focus group due to a helicoid structure is moved in the optical axis direction so that the user can focus on the lens barrel 1.

The lens barrel 1 is provided with a plurality of lenses 3 (3a, 3b, 3c, 3d). From FIG. 1, the lens 3a of the front fixed group is fixed to the fixed cylinder (second tubular member) 4, the focus lens (focus lens group) 3b is supported by the moving cylinder 2, and the lens 3c and the lens 3d of the relay group are supported. It is fixed to the fixed cylinder 4. The plurality of lenses 3 are fixed by fastening the holding ring to a screw portion (not shown) provided on the fixing cylinder or the moving cylinder. For example, the lens 3a is fastened and fixed by screwing the screw portion of the presser ring 5 into the screw portion 5a provided on the moving cylinder 2.
Here, the case where the focus lens 3b is held in the moving cylinder 2 will be described as an example, but the present invention is not limited to this configuration. The lens group held in the moving cylinder 2 includes the case of at least one single lens or a bonded lens.

The fixed cylinder 4 is formed with a female helicoid screw (female screw) 4a having a plurality of threads on the inner peripheral portion, and is screwed with a male helicoid screw (male screw) 2a of the moving cylinder 2 described later. An accessory fixing cylinder (mounting portion, third tubular member) 12 is screwed to the tip of the fixing cylinder 4.

Accessories (lens accessories) 6 such as a lens hood, a converter lens (teleconverter lens, wide converter lens), and a filter are provided with a screw portion 6a having an axial direction in a direction orthogonal to the optical axis, and the screw portion is provided with an accessory. The screw 7 is screwed in. The accessory screw 7 has a pin shape having a knurled portion on the outermost peripheral portion. The user can fix the accessory 6 to the accessory fixing cylinder 12 by picking the knurled portion with a finger and rotating the knurled portion. FIG. 1 shows a state in which the accessory 6 is inserted into the accessory fixing cylinder 12 from the object side end and fixed to the accessory fixing cylinder 12, and the tip of the screw portion of the accessory screw 7 abuts against the accessory fixing cylinder 12, and the accessory 6 is moved. The state where it is fixed and attached to the accessory fixing cylinder 12 is shown. At this time, a load F acts on the portion where the accessory screw 7 abuts in the axial direction of the accessory screw 7.

From FIG. 2, the moving cylinder 2 has a substantially cylindrical shape, and a male helicoid screw 2a having a lens 3 and a holding ring 5 on the inner peripheral side and a plurality of threads on the outer side is formed. Further, the moving cylinder 2 is provided with a screw portion 2b in a direction orthogonal to the optical axis direction, and a pin-shaped connecting member 8 is fastened to the screw portion 2b. The connecting member 8 slidably engages with the straight groove (groove portion) 9a of the operating ring (operating member) 9 described later. Due to the configuration of the connecting member 8 and the straight groove 9a, the relative rotation of the moving cylinder 2 and the operating ring 9 with respect to each other about the axial direction is restricted. That is, the connecting member 8 transmits the rotation of the operating ring 9 around the shaft to the moving cylinder 2. When the moving cylinder 2 advances in the optical axis direction, the connecting member 8 fastened to the moving cylinder 2 also rotates by rotating along the thread of the helicoid screw. The fixed cylinder 4 is provided with an oblique groove (hole) 4b through which the connecting member 8 centered on the optical axis is inserted in order to avoid interference caused by the rotation of the connecting member 8. The oblique groove 4b is provided at a location different in the optical axis direction (on the image side of the location where the female helicoid screw 4a is provided), which is independent of the location where the female helicoid screw 4a is provided on the fixed cylinder 4.

The operation ring 9 has a substantially cylindrical shape, and the inner peripheral side slides on the sliding surface with the fixed cylinder 4 and can rotate about the optical axis. Further, the operation ring 9 is restricted from moving in the optical axis direction by the regulation surface 4c of the fixed cylinder 4 and the operation ring retainer 10 fixed to the fixed cylinder 4 with a screw. The operation ring 9 is provided with a straight groove 9a so as to extend parallel to the optical axis direction, and the straight groove 9a penetrates the operation ring 9 in the radial direction centered on the optical axis. The connecting member 8 is slidably engaged with the straight groove 9a.

An operating ring rubber 11 is fitted on the outer peripheral surface of the operating ring 9. The operation ring rubber 11 has a non-slip function when the user rotates the operation ring 9.

With the above configuration, even if the accessory screw 7 is strongly tightened and a deforming force acts from the accessory fixing cylinder 12 to the fixing cylinder 4, the lens barrel 1 has an oblique groove at a position where the female helicoid screw 4a is not formed. Since the (hole) 4b has a cylindrical shape, the amount of distortion of the female helicoid screw 4a can be minimized. When the amount of strain of the female helicoid screw 4a becomes small, the torque unevenness when the operation ring 9 is rotated is reduced, and the operability of the user is improved. Further, the amount of backlash between the female helicoid screw 4a and the male helicoid screw 2a can be reduced, the amount of eccentricity and tilt of the moving cylinder 2 from the optical axis can be reduced, and fluctuations in optical performance can be suppressed.

Hereinafter, the lens barrel 1 according to the second embodiment of the present invention will be described with reference to FIG. The same part as in Example 1 described above is omitted.

From FIG. 3, the moving cylinder 20 has a substantially cylindrical shape, and a male helicoid screw 20a having a lens 3 and a holding ring 5 on the inner peripheral side and a plurality of threads on the outer peripheral side is formed. Further, the moving cylinder 20 is provided with a straight groove (groove portion) 20b parallel to the optical axis direction, and the tip end portion of the connecting member 21 described later is fitted.

The fixed cylinder 22 is formed with a female helicoid screw 22a having a plurality of threads on the inner peripheral side, and meshes with the male helicoid screw 20a of the moving cylinder 20 described later.

The operation ring 23 has a substantially cylindrical shape, and the inner peripheral side slides on the sliding surface with the fixed cylinder 22 and can rotate about the optical axis. The operation ring 23 is provided with a screw portion 23a in a direction orthogonal to the optical axis, and the connecting member 21 is screwed and fixed. The connecting member 21 has a pin shape, and its tip portion is slidably engaged with the straight groove 20b of the moving cylinder 20. Due to the configuration of the connecting member 21 and the straight groove 20b, the relative rotation of the moving cylinder 20 and the operating ring 23 with respect to each other about the axial direction is restricted. When the operating ring 23 rotates, the connecting member 21 fastened to the operating ring 23 also rotates. The fixed cylinder 22 is provided with an elongated hole portion 22b through which the connecting member 21 is inserted in order to avoid interference caused by the rotation of the connecting member 21. The elongated hole portion 22b is provided at a different location independent of the location where the female helicoid screw 22a is provided.

With the above configuration, the lens barrel 1 has a cylindrical shape in which the female helicoid screw 22a has no hole even when the accessory screw 7 is strongly tightened and a deforming force acts from the accessory fixing cylinder 12 to the fixing cylinder 4. Therefore, the amount of distortion of the female helicoid screw 22a can be minimized. When the amount of strain of the female helicoid screw 22a becomes small, the torque unevenness when the operation ring 23 is rotated is reduced, and the operability of the user is improved. Further, the amount of backlash between the female helicoid screw 22a and the male helicoid screw 20a can be reduced, and the amount of eccentricity and tilt of the moving cylinder 20 from the optical axis can be reduced, so that fluctuations in optical performance can be suppressed.
In this embodiment, the connecting member 8 and the connecting member 21 are shown to have a pin shape, but the connecting member may have a rectangular parallelepiped shape or an L shape formed of sheet metal or the like instead of the pin shape.

Further, by configuring the lens device having the lens barrel of the present invention and the image pickup device having the image pickup element arranged on the image plane of the lens device, the image pickup device having the effect of the present invention can be realized. .. Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

2: Moving cylinder 2a: Male helicoid screw (male screw)
3b: Lens 4: Fixed cylinder 4a: Female helicoid screw (female screw)
8: Connecting member 9: Operating ring

Claims (9)

A first tubular member that holds the lens group and has a male screw formed on the outer circumference.
A second tubular member in which a female screw to be screwed with the male screw is formed on the inner peripheral portion, and
An operating member that fits on the outside of the second tubular member and is rotatable around the axis of the second tubular member.
A connecting member that connects the first tubular member and the operating member and transmits the rotation of the operating member around the shaft to the first tubular member.
Have,
In the second tubular member, a hole penetrating in the radial direction is formed in a portion where the female screw is not formed.
The connecting member is inserted into the hole to connect the first tubular member and the operating member.
A lens device characterized by that. The lens device according to claim 1, wherein the first tubular member moves along the axis by the rotation of the operating member. The lens device according to claim 2, wherein the connecting member is fixed to the first tubular member and slidably engaged with a groove formed in an inner peripheral portion of the operating member. .. The lens device according to claim 2, wherein the connecting member is fixed to the operating member and slidably engaged with a groove formed in an outer peripheral portion of the first tubular member. The second tubular member has a mounting portion for mounting an accessory on the object side of the portion on which the female screw is formed.
The hole is formed on the image side of the portion where the female screw is formed.
The lens device according to any one of claims 1 to 4, wherein the lens device is characterized by the above. The lens device according to claim 5, wherein the mounting portion includes a third tubular member fixed to the second tubular member. The lens device according to claim 2, wherein the first tubular member holds a focus lens group. The lens device according to claim 5 or 6, wherein the accessory mounted on the mounting portion includes at least one of a teleconverter, a wide converter, a lens hood, and a filter. The lens device according to any one of claims 1 to 8.
An image sensor that captures the image formed by the lens device,
An imaging device characterized by having.

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