KR100247764B1 - York and magnet union structure of a linear motor - Google Patents

Abstract

The present invention relates to a yoke and a magnet coupling structure of a linear motor for a video camera, wherein a magnet is directly coupled to the yoke by a coupling part to a yoke fixed to an inner side and a bottom side of a barrel master, thereby coupling a magnet. As a separate adhesive is deleted, the bonding process is shortened accordingly, and the cost can be reduced to a minimum. In particular, the magnet is firmly coupled to prevent the detachment due to impact, thereby improving the bonding property.

Description

Yoke and magnet coupling structure of linear motor for video camera

The present invention relates to a yoke and a magnet coupling structure of a linear motor of a video camera, and more particularly, by directly coupling a yoke and a magnet for linearly reciprocating a zoom lens or a focus lens, the coupling process is shortened as well as the coupling property. It relates to a yoke and magnet coupling structure of a linear motor to improve the.

In general, a video camera including a camcorder or the like is a device for automatically adjusting the focus of light irradiated from a subject, recording an image reaching the image pickup device on a recording medium, and reproducing the recorded image. High performance is urgently required. In particular, speed, accuracy, low noise, and low power consumption are urgently required.

A video camera for responding to such a demand reaches a image pickup device through a zoom lens for zooming in or out with high magnification of light from a subject and a focus lens that is moved in the same manner, thereby forming a constant image on its surface.

As described above, the linear motor for moving the focus lens has a letter “c” on the inner side and the lower side of the barrel master 10 screwed to the lens barrel (not shown), as shown in FIGS. 1 to 3. The yoke 12 of the shape is fixed by the fixing screw 14, the through hole 12a and the semi-circle hole 12b are formed in the center and the upper portion of the inner surface of the yoke 12, respectively. In addition, the magnet 16 is fixed by the adhesive 18 so that the through hole 12a and the semi-circle hole 12b are included in one surface of the yoke 12.

The cell bobbin 20 is inserted into the air gap of the yoke 12 so as to reciprocate linearly, and the focus lens 22 for adjusting the focus of the incident light passing through the zoom lens (not shown) on the bottom of the cell bobbin 20. ) Is attached to the outside of the drive coil 24 is wound in a rectangular shape.

In the yoke and magnet coupling structure of the conventional linear motor configured as described above, the magnet 16 is adhered after injecting the adhesive 18 into the through holes 12a and the semi-circle holes 12b respectively formed on the inner surface of the yoke 12. After the yoke 12 is fixed to the top and bottom surfaces of the barrel master 10 with the fixing screws, the cell bobbin 20 with the focus lens 22 is inserted into the air gap of the yoke 12 so as to be linearly movable. To complete the assembly.

Then, when power is applied to the drive coil 24 wound on the cell bobbin 20 to operate the video camera, the cell bobbin is caused by the interaction between the magnetic field generated by the drive coil 24 and the magnet 16. (20) is magnetically floated to move straight reciprocally in the gap of the yoke (12). That is, the electromagnetic force generated by the driving coil 24 and the magnet 16 overcomes the load and gravity of the cell bobbin 20 itself, thereby maintaining the cell bobbin 20 in a linearly movable state.

At this time, the cell bobbin 20 moves until it stops at a position where focus can be adjusted along the zoom lens by a position signal of a feedback magnet associated with a position magnet and a magnetoresistive sensor (not shown), and then moves to the image pickup device. Make a prize

When the subject is moved during shooting and the image formed on the image pickup device is shifted due to the change in the light amount of the iris controlling the zooming operation and the incident light amount, or the image is not collected by the image pickup device by searching the image signal of the image pickup device. The cell bobbin 20 is moved forward and / or backward by an error amount to adjust the focus of the incident light reaching the image pickup device within a short time.

However, since the magnet for moving the focus lens-attached cell bobbin in a straight reciprocating manner is bonded to the yoke by the adhesive to the yoke as described above, the bonding process is delayed, and thus, the adhesive is particularly applied to the entire magnet. Not only is not evenly distributed, as well as easily detached from the yoke by the impact applied from the outside, the bondability is lowered, there is a problem that the cost is increased due to the use of the adhesive.

The present invention is to solve the above problems, an object of the present invention by directly coupling the magnet to the yoke, the separate adhesive for bonding the magnet is eliminated, thereby reducing the bonding process, as well as to minimize the cost The present invention provides a yoke and magnet coupling structure of a linear motor for a video camera, which can be reduced, and in particular, a magnet is firmly coupled to prevent the magnet from being separated in a horizontal direction by an impact, thereby improving the coupling property.

1 is a cross-sectional view showing a linear motor of a typical video camera,

Figure 2 is an exploded perspective view of the yoke and the magnet constituting the linear motor shown in FIG.

3 is a cross-sectional view of the yoke and magnet shown in FIG.

4 is an exploded perspective view illustrating a yoke and a magnet coupling structure of the linear motor for a video camera according to the present invention;

FIG. 5 is a cross-sectional view of the yoke and the magnet illustrated in FIG. 4.

Explanation of symbols on the main parts of the drawings

10: barrel master 14: fixed screw

20: cell bobbin 22: focus lens

24: drive coil 40: yoke

40a, 40b: first and second projections 44: magnet

44a, 44b: first and second semicircular holes

A characteristic of the present invention for achieving the above object is that the barrel master is screwed to the rear of the lens barrel, the yoke is fixed on the inner side, the lower surface of the barrel master, and the interaction with the drive coil on the inner surface of the yoke In the yoke and magnet coupling structure of a linear motor for a video camera for engaging a magnet that linearly moves a cell bobbin by an action, it is achieved by the magnet being directly coupled to the yoke by a coupling part provided in the yoke and the magnet. do.

Coupling portion according to a preferred embodiment of the present invention is formed on the inner surface of the magnet and the first projection protruding from the inner surface of the yoke and the second projection spaced downward at a predetermined distance from the first projection and the first and second projections It is achieved by being provided with first and second semi-circular holes respectively fitted in the.

Hereinafter, a preferred embodiment of the yoke and the magnet coupling structure of the linear motor for a video camera according to the present invention will be described in detail with reference to the accompanying drawings.

4 to 6 are views illustrating a yoke and a magnet coupling structure according to the present invention. In the present invention, for the convenience of description, like reference numerals refer to like elements in the related art.

The yoke 40 is fixed to the upper and lower surfaces of the barrel master 10 by the fixing screw 14, the magnet 42 is coupled to the yoke 40 by the coupling part, and the coupling part of the yoke 40 is fixed. The magnets are fitted to the first protrusions 40a protruding from the inner surface and the second protrusions 40b and the first and second protrusions 40a and 40b, which are spaced apart at a predetermined distance from the bottom thereof and protruded in the same line. And first and second semi-circular holes 42a and 42b formed in 42.

The insertion hole of the cell bobbin 20 with the focus lens 22 is inserted into the air gap of the yoke 40 including the magnet 42 so as to be reciprocated linearly, and the magnet 42 is formed on the outer circumferential surface of the cell bobbin 20. The drive coil 24 is wound so that an electromagnetic force is generated.

Referring to the operation of the yoke and the magnet coupling structure of the linear motor according to the present invention configured as described above in detail as follows.

When the first semi-circular hole 42a formed in the magnet 42 is inserted into the first protrusion 40a of the yoke 40 and then the inner surface of the yoke 40 and one surface of the magnet 42 are inserted in close contact with each other, the yoke ( As the second semi-circular hole 42b is firmly coupled to the second protrusion 40b of the 40, the magnet 42 is separated from the horizontal direction by the first and second protrusions 40a and 40b. This is to be avoided.

Thereafter, the yoke 40 coupled to the inner surface of the magnet 42 is fixed to the upper and lower surfaces of the barrel master 10 by the fixing screw 14, and thus the focus lens 22 is formed into the gap of the yoke 40. The power supply is applied to the driving coil 24 in order to photograph the subject or the object in the state where the assembly is completed by inserting the insertion hole of the attached cell bobbin 24.

Then, as the magnetic flux of the magnet 42 coupled to the yoke 40 crosses at right angles to the driving coil 24, the cell bobbin 20 starts to drive in the optical axis direction according to Fleming's left-hand law, and thus the constant according to zooming. It is stopped at a position to focus the image on the image pickup device.

As described above, according to the yoke and magnet coupling structure of the linear motor for a video camera according to the present invention, by directly coupling the magnet to the yoke, a separate adhesive for coupling the magnet is eliminated, so that the coupling process is shortened according to water. The cost can be reduced to a minimum, and in particular, the magnet is firmly coupled, and thus the separation in the horizontal direction is prevented by the impact, thereby improving the bondability.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (3)

The barrel master is screwed to the rear of the lens barrel, and the yoke is fixed to the inside and the bottom of the barrel master, and the inner surface of the yoke is coupled to the magnet for linearly moving the cell bobbin through the interaction with the driving coil. In the yoke and magnet coupling structure of the linear motor for a video camera, The yoke and magnet coupling structure of the linear motor for a video camera, characterized in that the magnet is directly coupled to the yoke by the coupling portion provided in the yoke and the magnet. According to claim 1, The coupling portion is formed on the inner surface of the magnet and the first projection protruding from the inner surface of the yoke and the second projection spaced downward predetermined distance to the first projection and the inner surface of the first projection and the second projection The yoke and magnet coupling structure of the linear motor for a video camera, characterized in that the first and second semi-circular holes are fitted into each other. The yoke and magnet coupling structure of a linear motor for a video camera according to claim 2, wherein the first and second protrusions protrude in the same line.

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