JP2002090607A - Lens interval adjusting device of lens for cctv camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the lens interval adjusting device of a lens for a CCTV camera the miniaturization of which has been requested strongly, which is convenient for miniaturization and whose cost is drastically reduced. SOLUTION: This lens interval adjusting device of the lens for a CCTV camera is equipped with an operation ring 1, provided in a rotationally immobile state corresponding to a camera main body, a cam barrel 2 housed in the ring 1 in a turnable state, a driving means 3 for driving and rotating the cam barrel 2, and a lens frame 4, provided for each lens group 40A or 40B and moving linearly in the center axis direction of the ring 1, while engaging with a cam groove 2A formed on the cam barrel 2. The cam barrel 2 is formed of a thin plate having flexibility and is inserted in the ring 1 in the turnable state and brought into contact therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a CCTV used for a surveillance camera.
The present invention relates to a lens spacing adjustment device for a camera lens.

[0002]

2. Description of the Related Art For example, various surveillance cameras (hereinafter, referred to as CCTV cameras) which are extremely small in size as compared with general photographing cameras have been developed and used. In this CCTV camera, various lens interval adjusting devices have been proposed and developed in order to adjust the focal length and the focus position by moving the position of the CCTV camera lens.

[0003] For example, there is known a lens spacing adjusting device using a helicoid using a combination of multiple threads. However, when using this helicoid, only one group of lenses can move. In addition, when this helicoid is used, movement in the Z direction perpendicular to the optical axis and centering of the optical axis are also used. Therefore, in a long focal length lens, axial misalignment is caused to cause inconvenience such as image skipping. .

Therefore, as such a lens spacing adjusting device, a device using cylindrical cam means capable of moving two or more lenses at the same time has been developed. However, it is necessary to form a cam groove in the cylindrical cam used for the cylindrical cam means. In particular, in the case of a CCTV camera which tends to be miniaturized, the cam groove is formed on a cylindrical curved surface. Is extremely difficult to machine. In particular,
When trying to move a plurality of lens groups, the number of cam grooves increases, so that processing becomes more difficult and much time is required.

In order to solve such a problem, for example, a cam of a flat plate is used (hereinafter referred to as a cam plate).
By forming the CCT, the CCT, which tends to be particularly compact, is
There has been proposed a camera for a V-camera, which has a structure in which a cam groove is easily formed. However, when this cam plate is used, the cam plate is moved in the left-right lateral direction (Z-axis) perpendicular to the optical axis, resulting in an inconvenience of increasing the size of the entire apparatus.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned situation of a lens for a CCTV camera, which is strongly demanded for miniaturization.
An object of the present invention is to provide a lens spacing adjustment device for a CCTV camera lens, which is convenient for miniaturization, can significantly reduce cost, and can easily move a plurality of lens groups. And

[0007]

SUMMARY OF THE INVENTION The present invention provides an operating ring provided in a state in which it is not rotatable with respect to a camera body, a cam barrel housed in a rotatable state within the operating ring, and a driving means for driving the cam barrel to rotate. And a lens frame that linearly moves in the direction of the central axis of the operation ring while engaging with a cam groove formed in the cam cylinder.
A lens spacing adjustment device for a V-camera lens, wherein the cam barrel is formed of a flexible thin plate, and is inserted into and tightly attached to the operation ring in a curved state and a rotatable state. It is characterized by:

The cam cylinder has a substantially C-shaped cross section in which a part of the outer peripheral surface is chipped.
It is preferable that a guide means which is formed in a letter shape and which guides the movement in the optical axis direction by restricting the rotation operation of the lens frame is provided in the lacked space.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2
1 shows a lens spacing adjusting device for a CCTV camera lens according to the present invention. This lens spacing adjusting device is used for a surveillance camera which is extremely small as compared with a general photographic camera. , An operating ring 1, a cam barrel 2, a driving means 3, and a lens frame 4. In addition, the code | symbol 5 in a figure shows a guide means.

The operation ring 1 is provided with a male thread 1A having a male thread cut at a base end thereof, and is screwed to a mount 6 of the monitoring camera main body so as to be in a rotationally immobile state. A male screw portion 1B having an external thread is also provided at the distal end portion of the operation ring 1, and the male screw portion 1B is provided.
A focus lens frame 7 to which a focus lens group 7A is attached is screwed integrally. On the other hand, on the base end side of the operation ring 1, a through hole 1 for installing a driving unit 3 described later is provided.
C is drilled. In addition, the formation angle range W of the through hole 1C is determined by a center angle α of a cam groove 2A of the cam cylinder 2 described later.
(See FIG. 4).

As shown in FIG. 3, the cam cylinder 2 is made of a thin plate made of a flexible material such as rubber, for example. As shown in FIG. On the other hand, it is bent into a substantially C-shaped cross-section with a part of the outer peripheral surface missing, and is inserted into the operation ring 1 in a tightly contacted state and in a state where a smooth rotation operation is possible. That is, this cam cylinder 2
Is a constant angle range β (FIG. 4) along the inner peripheral surface of the operation ring 1.
), And a space S is formed in the remaining angular range (360-β) of the inner peripheral surface. Normally, since the cam cylinder 2 is used for a small camera for monitoring, it is extremely small in size as compared with a general photographic camera, and has a short focal length in many cases. In this case, the cam cylinder 2 may be formed as a long focal point. Therefore, only in such a case, the guide means 5 described later is provided in the space S. This cam cylinder 2
Are provided on both ends of the operation ring 1 (which function as stoppers), which will be described later, so that the short-focal point can be in close contact with the inner peripheral surface of the operation ring 1. , 22 are abutted, for example, in this embodiment, are screwed.

In the cam barrel 2 of this embodiment, a pair of cam grooves 2A are formed on the base end side and the tip end side, respectively, to move the two lens frames 4A and 4B in the optical axis direction. A roller 41 of the lens frame 4 described later is engaged with the cam groove 2A. As shown in FIG. 3, the cam groove 2A can be formed when the cam cylinder 2A is in a flat state before the cam cylinder 2A is curved, so that the forming process can be easily performed.

The driving means 3 rotates the cam barrel 2 to move the lens frame 4 to an appropriate position during zooming or focusing during monitoring by the monitoring camera, and is driven electrically. That is, in this embodiment, as the driving means 3, a driving gear 32 fixed to an output shaft 31A of a small motor 31 not shown, a ring gear 33 meshing with the driving gear 32, and an inner peripheral surface of the ring gear 33 And a connecting shaft 34 integrally connecting a part of the cam barrel 2 and the outer peripheral surface of the cam barrel 2.

The ring gear 33 is installed so as to freely rotate with respect to a ring-shaped receiving portion 1D formed on the operating ring 1. Immediately below the receiving portion 1D, the above-described through-hole 1 is provided.
C is partially formed. The upper end of the connecting shaft 34 is press-fitted into the ring gear 33, and the lower end is caulked to the cam cylinder 2 and is integrally assembled. Also,
The middle side of the connecting shaft 34 is inserted through the through hole 1C,
The cam barrel 2 is rotated along the through hole 1C in conjunction with the rotation operation of the ring gear 33, and the cam cylinder 2 is integrally rotated. The connecting shaft 34 may be attached to the cam cylinder 2 by a stop.

The lens frame 4 includes a first lens frame 4A fixedly supporting a variable power lens group 40A used for a small surveillance camera and a variable power lens group 40B also used for a small surveillance camera. The operation ring 1 is linearly moved in the direction of the center axis of the operating ring 1 while being engaged with the guide grooves 2A formed in the cam cylinder 2 respectively.
For this reason, a pair of rollers 41 are respectively attached to these lens frames 4A and 4B by the shaft body 42, and the first and second lens frames 4A and 4B.
A and 4B are attached rotatably. Further, a slide hole 43 for inserting a slide member 52 to be described later is formed in the lens frames 4A and 4B, and a bush 44 (see FIG. 2) is provided in the slide hole 43 so that a smooth movement operation can be performed. Can be done. In addition,
The variable power lens group 40A and the variable power lens group 40B are extremely small in size as compared with a general camera lens for photography.

The guide means 5 is provided to prevent the lens frame 4 from shifting in the Z-axis direction (see FIG. 4) perpendicular to the optical axis when the lens frame 4 moves in the optical axis direction. It is used only when a long focal length lens is used in a small CCTV camera. Not used for wide lenses. This guide means 5 is unnecessary particularly when the lens to be used has a short focal length (that is, when the short-focus cam barrel 2 is used). This is because the cam cylinder 2 can be brought into close contact with the inner peripheral surface of the operation ring 1 by a restoring force.
This is because, in a CTV camera, particularly when the cam cylinder 2 has a short focus, the cam cylinder 2 can surely adhere to the inner peripheral surface of the operation ring 1.

The guide means 5 according to this embodiment comprises a pair of disk-shaped support members 51 provided on the left and right sides and a pair of bar-shaped slide members 52 provided in parallel. The left and right support members 51 are integrally screwed to the proximal inner surface 11 and the distal inner surface 12 (see FIG. 2) of the operation ring 1 with screws or small screws, respectively. The part is fixed with screws. The support body 51 abuts on the base end face 21 and the tip end face 22 of the cam cylinder 2 rotatably provided on the inner peripheral surface of the operation ring 1. The cylinder 2 is sandwiched from both end surfaces, thereby preventing the cam cylinder 2 from coming into close contact with the operation ring 1 and, for example, preventing a situation in which the cam cylinder 2 is slanted and loses its shape.

The slide member 52 guides the lens frame 4 slidably in the axial direction of the operation ring 1 and is inserted through a slide hole 43 provided in the lens frames 4A and 4B. The slide member 52 is provided on the operation ring 1.
Is extended from the base end side to the front end side, but in the operation ring 1, it passes through here using a space portion S (see FIG. 4) where the cam cylinder 2 is not disposed.

Next, the operation of the lens spacing adjusting device for the CCTV camera lens used in the monitoring camera according to this embodiment will be described with reference to FIG. For example, when performing zooming or focusing during monitoring, when an operation button (not shown) is turned on, the motor 31 of the driving unit 3 operates. Thereby, the driving gear 32
Starts rotating, and the ring gear 33 meshing therewith rotates, so that the cam cylinder 2 integrally connected to the ring gear 33 and the connecting shaft 34 simultaneously rotates.

Accordingly, the cam groove 2A (see FIG. 4) formed in the cam cylinder 2 translates and shifts in the same direction. On the other hand, the moving directions of the lens frames 4A and 4B, to which the rollers 41 engaged with the cam grooves 2A are attached, are restricted by the slide members 52 of the guide means 5, and the movement is allowed only in the axial direction of the operation ring 1. Have been. Thereby, the lens frame 4
A and 4B move in the axial direction of the operation ring 1 in accordance with the position of the cam groove 2A that changes. As a result, the lens frames 4A, 4B
Can be moved to an appropriate position according to zooming and focusing.

In this embodiment, the cam barrel 2 is rotated by the motor 31 and the lens frame 4 is moved by this. However, for example, as shown in FIG. 5, it can be used as a surveillance camera. Then, the manual knob 5
3 may be provided, which may be slid along the through hole 1C of the operation ring 1 to rotate the cam cylinder 2.

[0022]

As described above, according to the present invention, the cam cylinder is formed of a flexible thin plate, and is inserted and adhered in the zoom cylinder in a curved state and a rotatable state. In other words, even in surveillance cameras that are significantly smaller than general-purpose photography cameras,
Since the cam groove can be bored in a flat state in which processing is easy, even if it is small, manufacturing is easy and cost can be greatly reduced.

Further, according to the present invention, the cam cylinder itself is
For example, if it is formed into a substantially C-shaped cross-section with a part cut off without forming a complete cylindrical shape, it becomes possible to install the guide means in the chipped part. Since there is no need to provide an extra space and downsizing can be further achieved, this is advantageous particularly in a surveillance camera which requires strong downsizing.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a lens spacing adjusting device for a CCTV camera lens according to the present invention.

FIG. 2 is a sectional view of the upper half of the lens space adjusting device of the CCTV camera lens.

FIG. 3 is a perspective view showing a state before a cam cylinder used in the device is inserted into an operation ring.

4 is a cutaway perspective view showing a state where the cam cylinder shown in FIG. 3 is inserted into an operation ring.

FIG. 5 is an exploded perspective view of a main part of a lens gap adjusting device for another CCTV camera lens according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 operation ring 1C through hole 2 cam cylinder 2A cam groove 21 base end face 22 tip end face 3 drive means 31 motor 32 drive gear 33 ring gear 34 connecting shaft 4 lens frame 40A variable power lens group 40B variable power lens group 41 roller 43 slide hole 44 bush 5 guide means 51 support body 52 slide member 6 mount part of camera body 7 focus lens frame

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/232 A 5/232 G02B 7/04 D

Claims (2)

[Claims] An operating ring provided in a state in which the operating body is not rotatable with respect to a camera body; a cam cylinder rotatably accommodated in the operating ring; a driving unit for rotating the cam cylinder; A lens frame for a CCTV camera lens comprising: a lens frame that linearly moves in the direction of the center axis of an operation ring while engaging with a cam groove formed in a cylinder, wherein the cam cylinder has a flexible thin plate. And a lens spacing adjustment device for a CCTV camera lens, wherein the lens spacing adjustment device is formed in a curved state and rotatably inserted into and tightly attached to the operation ring. 2. A cam cylinder having a substantially C-shaped cross section with a part of the outer peripheral surface being chipped, and restricting the rotation of the lens frame in the chipped space toward the optical axis. 2. A lens spacing adjusting device for a CCTV camera lens according to claim 1, further comprising guide means for guiding the movement of the lens.