KR970001592Y1 - A zooming system for video camera - Google Patents

Abstract

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Description

Video camera zooming system

1 is a cross-sectional view showing a zooming system of a conventional video camera.

2 is a cross-sectional view showing a zooming system of a video camera according to the present invention.

* Explanation of symbols for main parts of the drawings

21: Forward barrel 23: Zoom barrel

27: drive motor 34: circuit board

35: fragmentation

The present invention relates to a zooming system of a video camera, and more particularly, to a zooming system capable of accurately detecting the position of a zoom lens using a potentiometer.

In general, video cameras and general AF cameras are being miniaturized to be easy to operate and move. Recently, an inner focus type camera has been provided, which is used to automatically adjust the focus of a lens on a subject. A zoom less and focus lens is linearly moved along the optical axis. In addition, since the position of the focus lens is changed according to the position of the zoom lens, its accurate position detection is very important for the camera.

As shown in FIG. 1, the zooming system of such a conventional video camera has a CCD (13) at the rear end of the front barrel (1) in which the group 1 lens (9) and the group 3 lens (11) are mounted at both ends thereof. A rear barrel (2) equipped with a solid state image pickup device (2) is fixedly installed, and inside the front barrel (1) and the rear barrel (2), two guide pins (6) (6 '), respectively, parallel to the optical axis; On the other hand, one transfer screw (5) (5 '), each of which is equipped with a driven gear (5a) (5a'), is rotatably installed on one side thereof. In addition, the guide pin 6 and the transfer screw 5 of the front barrel 1 are provided with a zoom barrel 3 equipped with a zoom lens 2 so as to be movable, and the rear barrel 2 Focus barrel 4 equipped with a four-group lens 12 (Focus lens) is installed on the guide pin 6 'and the transfer screw 5' to be movable. Each of the transfer screws 5 and 5 Screws corresponding to each of the conveying screws 5 and 5 'are formed in the zoom barrel 3 and the focus barrel 4 of the portion coupled to'). In addition, the driven gear 5a mounted on the transfer screw 5 of the front barrel 1 is engaged with the drive gear 7a of the zoom motor 7, and is connected to the transfer screw 5 'of the rear barrel 2. The mounted driven gear 5a 'is meshed with the drive gear 8a of the focus motor 8. A potentiometer 14 is fixedly installed on one side of the inner circumferential surface of the front barrel 1, and a coupling groove 3a is formed on the outer circumferential surface of the zoom barrel 3 corresponding to the potentiometer 3a. The variable magnet 15 is fixedly installed so that the tip thereof contacts the potentiometer 14.

In the zooming system of the conventional video camera configured as described above, when the user presses the zoom button (tele or wide), the zoom motor 7 is driven, and the driven gear 7a attached thereto is rotated and engaged with the driven gear 5a. By rotating the rotational force is transmitted to the transfer screw (5). Accordingly, the zoom barrel 3 is moved parallel to the optical axis along the guide pin 6 by the rotation of the transfer screw 5, so that the zoom motor 7 is reversed by the electrical signal of the light receiver. As it is rotated, the zoom barrel 3 is advanced or driven. At this time, the focus barrel (4) is changed according to the position of the zoom barrel (3), which is installed on the outer circumferential surface of the zoom barrel (3), the front end of the variable variable (15) is moved with the potentiometer ( 14, the moving position is detected by the potentiometer 15. As shown in FIG. As a result, the focus motor 8 is rotated forward and backward, and the rotational force is transmitted to the driving gear 8a, the driven gear 5a 'and the transfer screw 5' connected thereto. Along the guide pin 6 ', it moves forward or backward parallel to the optical axis to automatically adjust the focus of the lens on the subject.

However, the zooming system of such a conventional video camera has been a factor in increasing the cost of the product because the potentiometer has many components, and it is difficult to assemble the bar because the tip of the variable is required to be exactly in contact with the potentiometer. In addition, there was a problem that the position detection degree is reduced by the assembly tolerance. As a result, the change of the position of the focus barrel according to the position of the zoom barrel, that is, the exact focusing is not achieved, causing a problem of deterioration in image quality.

The present invention has been devised to solve the problems described above, and can be expected to reduce atomic weight with a simple structure, is easy to assemble, and improved to obtain accurate image quality by inducing accurate focusing by accurately detecting the position of the zoom lens. Its purpose is to provide a zooming system for a video camera.

In order to achieve the above object, the present invention includes a zoom barrel equipped with a zoom lens, a focus barrel equipped with a focus lens, a front barrel including the zoom barrel, and a video controlled by a driving motor. In the zooming system of the camera,

A circuit board fixed to one inner circumferential surface of the front barrel and coated with a stripe conductive material in a longitudinal direction;

A contact piece fixedly installed at an outer circumferential surface of the zoom barrel at a position corresponding to the conductive material of the circuit board, and having a free end elastically contacting the conductive material; It is characterized in that it is provided to detect the movement position of the zoom barrel by the operation of the drive motor.

This invention can be suitably used not only for video cameras, but also for general AF cameras (Auto Focus Camera) or optical applications.

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

2 is a cross-sectional view showing a zooming system of a video camera according to the present invention.

As shown therein, the zooming system of the video camera according to the present invention, the adjusting device is fixed to the front barrel 21 and the rear end of the first group lens 29 and the three group lens 31 are mounted at both ends thereof. It is made of a combination of the rear barrel 22 having a CCD 33, the inside of the front barrel 21 and the rear barrel 22, each of the two guide pins 26 (26 ') parallel to the optical axis. And one transfer screw 25 (25 ') having driven gears 25a, 25a' on each side thereof. In addition, the guide pin 26 and the transfer screw 25 of the front barrel 21 are provided with a zoom barrel 23 mounted with a zoom lens 30 so as to be movable, and the rear barrel 22. The guide pin 26 'and the transfer screw 25' are provided with a focus barrel 24 mounted with four focus lenses 32 so as to be movable on each of the transfer screws 25 and 25 '. The mounted driven gears 25a and 25a 'are meshed with the respective drive motors, namely, the drive gears 27a and 28a connected to the zombie motor 27 and the focus motor 28. In addition, the circuit board 34 is fixedly installed on one side of the inner circumferential surface of the front barrel 21 according to the characteristics of the present invention. The surface thereof is coated with zinc (Zn), which is a conductive material, in parallel with the optical axis. On the outer circumferential surface of the zoom barrel 23 corresponding thereto, the contact piece 35 is fixedly installed by thermal caulking such that its free end is in contact with the zinc Zn.

The free end of the contact piece 35 is formed with a contact portion 35a extending from the free end and bent inward at an angle to facilitate sliding contact with the zinc Zn. In this case, the contact piece 35 is preferably formed of an elastic material having a predetermined elasticity.

In the zooming system of the video camera according to the present invention configured as described above, when the user presses the zoom button, the zoom motor 27 rotates forward or reverse in the zooming direction, and the rotational force is the driving gear 27a and the driven gear 25a. It is delivered to the transfer screw 25 through). Accordingly, the zoom barrel 23 is guided to the guide pin 26 by the rotation of the transfer screw 25, so that the zoom barrel 23 is moved forward or backward in parallel with the optical axis. At this time, the position of the focus barrel 24 is changed according to the moving position of the zoom barrel 23. The position of the zoom barrel 23 is fixed to the outer circumferential surface thereof and on the folding piece 35 moved with it. Is detected. That is, since the contact portion 35a formed at the free end of the contact piece 35 is always in elastic contact with the zinc Zn of the circuit board 34 provided on the inner circumferential surface of the front barrel 21, the potentiometer according to the movement thereof By this, the position of the zoom barrel 23 is accurately detected. Accordingly, the focus motor 28 is rotated forward and backward, and the rotational force is transmitted to the transfer screw 25 'through the driving gear 28a and the driven gear 25' connected thereto, thereby mounting the focus lens 31. The focused barrel 24 is advanced or retracted parallel to the optical axis along the guide pin 6 'to automatically adjust the focus of the lens on the subject.

According to the present invention, the cost reduction of the product can be expected by a simple configuration of applying a conductive material to the circuit board, and the assembly tolerance is fundamentally prevented since the assembly is easy and the contact is elastically contacted with the conductive material. Can be detected accurately. Therefore, accurate focusing is performed on the subject of the focus lens according to the position of the zoom lens, thereby obtaining a clear image quality.

Claims (3)

(Correction) A zooming system of a video camera having a zoom barrel equipped with a zoom lens, a focus barrel equipped with a focus lens, a front barrel including the zoom barrel, and the like, and whose focus is automatically adjusted by a driving motor, A circuit board 34 fixed to one inner circumferential surface of the front barrel 21 and coated with a stripe conductive material in a longitudinal direction; A contact piece 35 fixedly installed at an outer circumferential surface of the zoom barrel 23 at a position corresponding to the conductive material of the circuit board 34 and having a free end elastically contacting the conductive material; The zooming system of the video camera, characterized in that for detecting the movement position of the zoom barrel (23) by the drive of the drive motor (27) (Correct) The zooming system of a video camera according to claim 1, wherein said conductive material is zinc (Zn). (Correction) The zooming system of a video camera according to claim 1, wherein the free end of the contact piece (35) is bent inwardly at a predetermined angle to facilitate contact with the conductive material of the circuit board (34).