JP3079416B2 - Dust proof device for CCTV camera lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dustproof device for a lens for a CCTV camera.

[0002]

2. Description of the Related Art As a lens for a CCTV camera (surveillance camera), there is a lens having a built-in electric automatic iris device that changes the size of an iris according to ambient brightness. In this lens, a power supply and control cable to the motor is led from the inside of the lens barrel to the outside. Further, there is known a lens for a CCTV camera of a type in which focusing and zooming are powered, and power supply and control thereof are performed via a similar cable.

[0003] On the other hand, CCTV cameras are installed both indoors and outdoors. Particularly outdoors, they are placed in severe natural environments. For example, when sulfurous acid gas in the air enters the lens barrel, rust is generated on the diaphragm blades (usually made of phosphor bronze) of the automatic diaphragm device, thereby slowing down the movement. In addition, small insects enter the lens barrel and adhere to the aperture blades, similarly slowing down their movements, and in the worst case, failing to operate.

[0004] These problems can be solved theoretically by increasing the hermeticity of the lens barrel. General hermeticity is known, for example, for lens structures for waterproof cameras. However, in the CCTV camera lens, there is a structure that does not normally exist in a photographic lens in which a cable is led out of the lens barrel. For this reason, conventionally, it is difficult to ensure the hermeticity of the cable introduction part, and in particular, a lens for a CCTV camera placed in a severe natural environment can completely solve the problem of malfunction of the aperture blade. Did not. A similar problem occurs in a lens for a CCTV camera of a type in which power supply and control to a motor for focusing and zooming are performed via a similar cable.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the hermeticity of a cable lead-out part in a lens for a CCTV camera of a type in which a cable is led out of a lens barrel.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a lens for a CCTV camera which leads a cable from the inside to the outside of a cylindrical portion of a lens barrel. An elastic sheet member located on the outer surface of the cylindrical portion so as to surround the cable lead-out hole; a pair of half members located on the outer surface side of the elastic sheet member; and formed on the abutting end surfaces of the pair of half members, respectively. A semi-circular groove for clamping the cable; connecting means for connecting the pair of half-split members to each other with the cable sandwiched between the semi-circular grooves; And a fixing means for fixing the elastic sheet member to the outer surface of the cylindrical portion of the lens barrel. The inner diameter of the elastic sheet member in the free state of the cable insertion hole, and a pair of half Butt split members The inner diameter of the composite circular by a pair of semi-circular grooves when the is smaller than the outer diameter of the cable in the free state
The cable insertion hole of the elastic sheet member is
With a high cone on the pair of half members
And a pair of halves are barrel-shaped.
When fixed to the part, this conical deformation is crushed
It is characterized by:

[0007] The elastic sheet member has a cable insertion hole
Can be formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 and FIG.
1 shows an embodiment of a CTV camera lens 10.
The CCTV camera lens 10 has a rear end
It has a screw-in C mount 11 that is screwed to the C mount of the V camera body. Lens for CCTV camera 10
The outer shape of this threaded C-mount 1
1, rear barrel 12, front barrel 13, and dustproof glass 14
And a tip cover 15 having the following. O-rings 16 are provided between the rear barrel 12 and the front barrel 13 and between the front barrel 13 and the front cover 15 for dustproof and waterproof.

[0009] Inside the CCTV camera lens 10,
Imaging lens groups L1 and L2 are provided. In the illustrated example, the imaging lens group L1 is a focus lens group. On the outer periphery of the imaging lens unit L1, an annular automatic aperture device unit 20 is located. The automatic aperture device unit 20 is fixed to the inner periphery of the rear end of the front lens barrel 13 with a fixing screw 21. ing. In the automatic iris unit 20,
A well-known element (not shown) such as a drive motor and aperture blades that are opened and closed by the drive motor is stored.
At the front end of the automatic iris device unit 20, an automatic iris control board 22 is fixed.
A cable 24 for supplying power to the drive motor in the automatic aperture device unit 20 and controlling the drive motor is derived from the above.

The cable 24 is connected to the front lens barrel 13 by C
A cable lead-out hole 17 for leading out from the inside to the outside of the CTV camera lens 10 is provided.
A dust-proof device fixing recess 18 is formed on the outer surface of the frame 3 so as to surround the cable lead-out hole 17.

The dustproof device 3 fixed in the fixing recess 18
0 is an elastic sheet material 31, a pair of half blocks (members)
32, a connection screw 33 for connecting and fixing the pair of half blocks 32 to each other, and a fixing screw 34 for fixing the connected half block 32 and the front barrel 13 to each other.

The elastic sheet material 31 is made of, for example, a rubber material, and has an insertion hole 31a through which the cable 24 is inserted.
And an insertion hole 31b for the fixing screw 34. Insertion hole 3
The inner diameter of 1a is smaller than the outer diameter of the cable 24 in a free state (a state before being fixed to the CCTV camera lens 10).
The elastic sheet material 31 may have a slit 31c communicating with the insertion hole 31a. If the slit 31c is formed, the elastic sheet material 31 is formed from the radial direction of the cable 24.
Can be attached and detached.

Each of the pair of half blocks 32 is formed in a rectangular block shape from rubber, resin, metal, or the like, and has a semicircular groove 32b on its butted end surface 32a. The semicircular groove 32b is formed by a pair of half blocks 32.
Are joined together at the butted end face 32a to form a circular shape as a whole.
Is smaller than the outer diameter of the free state (the state before being fixed to the CCTV camera lens 10).

Each of the pair of half blocks 32 is formed with an insertion hole (a stump hole) 32c and a screw hole 32d of a connection screw 33 which are orthogonal to the cable 24 leading-out direction and are orthogonal to each other. Insertion hole 32 of split block 32
c is inserted into the other half block 3
The second screw hole 32d is screwed into the second screw hole 32d. Also,
Each of the pair of half blocks 32 has a cable 24.
The insertion hole 32e of the fixing screw 34 is formed in parallel with the lead-out direction. After the fixing screw 34 is inserted into the screw insertion hole 32e and the screw insertion hole 31b of the elastic sheet material 31,
A fixing screw hole 18 formed in a fixing recess 18 of the front barrel 13
a.

In assembling the dustproof device 30 having the above-described configuration, the cable 24 is led out from the cable lead-out hole 17 of the assembled CCTV camera lens 10, and the insertion hole 31a of the elastic sheet material 31 is first fitted into the lead-out portion. . Since the inner diameter of the insertion hole 31a is smaller than the outer diameter of the cable 24, the inner peripheral edge of the insertion hole 31a is slightly deformed and conical at this time. This conical deformation 31a '
On the two sides. If the slit 31c is formed,
The elastic sheet material 31 can be fitted from the radial direction of the cable 24 by opening the insertion hole 31a.

Next, the semicircular grooves 3 of the pair of half blocks 32
The cable 24 is fitted to 2b, the butted end faces 32a are butted, and in this state, the pair of half blocks 32 are fixed by the connection screws 33. That is, the two connection screws 33 are inserted into the respective insertion holes 3 of the one half block 32.
2c and the screw hole 32 of the other half block 32
Screw to d. Since the inner diameter of the composite circle of the pair of semicircular grooves 32b is smaller than that of the cable 24, the cable 24 is compressed and the gap between the cable 24 and the semicircular groove 32b is eliminated.

A pair of half blocks 3 is connected by connecting screws 33.
Then, the pair of half blocks 32 and the elastic sheet material 31 are fixed to the front barrel 13 by the fixing screws 34.
Is fixed to the fixing recess 18. That is, the two fixing screws 34 are inserted into the screw insertion holes 32 e of the half block 32 and the screw insertion holes 31 b of the elastic sheet material 31, and the front lens barrel 13 is
Screw holes 18a. Then, the half block 32 deforms the conical deformation 31 a ′ of the elastic sheet material 31 into a planar shape and makes the elastic sheet material 31 adhere to the outer periphery of the cable 24. The cable 24 is compressed by the semicircular groove 32b of the half block 32 so that there is no gap between the two and the conical deformation 3
By compressing 1a 'into a planar shape, a double dustproof structure is completed. Therefore, even in a severe natural environment, the cable 10 for the CCTV camera 10
It is possible to maintain the dustproofness of the insertion portion into the inside.

The above is an embodiment in which the present invention is applied to the introduction portion of the cable 24 of the automatic aperture device unit 20, but the present invention can be similarly applied to a cable for focusing and zooming.

[0019]

According to the present invention, in a lens for a CCTV camera of a type in which a cable is introduced into a lens barrel, the hermeticity of the cable introduction portion can be improved with a simple structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a dustproof device for a CCTV camera lens according to the present invention.

FIG. 2 is an exploded perspective view showing a cable lead-out portion of the lens of FIG.

[Explanation of symbols]

 Reference Signs List 10 Lens for CCTV camera 12 13 Lens barrel 17 Cable lead-out hole 18 Fixing recess 20 Automatic aperture device unit 21 Fixing screw 24 Cable 30 Dustproof device 31 Elastic sheet material 31a Insertion hole (for cable) 31b Screw insertion hole 32 Half block (half) (Split member) 32a Butt end face 32b Semicircular groove 32c Screw insertion hole 32d Screw hole 32e Screw insertion hole 33 Connection screw (connection means) 34 Fixing screw (fixing means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 7/02 H04N 5/225 F16L 3/10 H02G 7/00

Claims (1)

(57) [Claims] 1. A lens for a CCTV camera for guiding a cable from the inside to the outside of a cylindrical part of a lens barrel, comprising: a cable lead-out hole formed in the cylindrical part of the lens barrel; An elastic sheet member positioned on the outer surface of the cylindrical portion so as to surround the cable lead-out hole; a pair of half members positioned on the outer surface side of the elastic sheet member; and an abutting end face of the pair of half members, respectively. A formed semicircular groove for holding the cable; connecting means for connecting the pair of half members to each other while sandwiching the cable between the semicircular grooves; and connecting with the connecting means. And a fixing means for fixing the elastic sheet member to the outer surface of the cylindrical portion of the lens barrel. An inner diameter of the elastic sheet member in a free state of a cable insertion hole, and a pair of Half The inner diameter of the composite circle formed by the pair of semicircular grooves when the members are abutted is smaller than the outer diameter of the cable in a free state, and the cable insertion hole of the elastic sheet member is a pair of semicircular grooves when the cable is inserted. A dustproof device for a CCTV camera lens, wherein a high conical deformation is generated on a split member side, and the conical deformation is crushed by a pair of half-split members.