JPH0566336A - Apparatus with built-in lens - Google Patents

Abstract

PURPOSE:To provide an apparatus with a built-in lens which is small in size and light in weight. CONSTITUTION:In the apparatus with the built-in lens that a lens holding member 2 holding a lens 1 in an optical axis direction along guide members 3 and 4, a yoke 8 having a coil which is concentrically disposed by enclosing the holding member 2 formed of a magnetic material and plural recessed parts or projection parts 8a concentrically juxtaposed on the inside circumferential surface of the yoke 8 in the optical axis direction are provided. In such a case, the volume and the weight of a lens driving device can be drastically reduced and a special fixing mechanism for the lens holding member need not be provided. Besides, the apparatus with the built-in lens can be made small in size and light in weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention incorporates a lens holding member for holding a moving lens, such as a still camera, a video camera, and various other observation devices, and moves the lens holding member along the optical axis. The present invention relates to a device with a built-in lens.

[0002]

2. Description of the Related Art Conventionally, in a device with a built-in lens of this type, focus adjustment and zooming are performed by moving a lens group of an image pickup system back and forth in the optical axis direction, and the power for moving this lens group is an electromagnetic type. It's got from the motor. As means for transmitting power from the electromagnetic motor to the lens group, there are those that reduce the rotation of the motor by a gear train to convert it into high torque and transmit it, and those that transmit the power of the motor by a timing belt or a rubber belt. is there.

[0003]

However, the above-mentioned conventional example has a problem that it is difficult to reduce the size and weight of the lens-equipped device.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and provide a small-sized and lightweight device with a built-in lens.

[0005]

According to the present invention, there is provided a lens holding member made of a magnetic material for holding a lens, a yoke having coils arranged concentrically around the lens holding member, and a yoke of the yoke. Since the inner peripheral surface is provided with a plurality of concave portions or convex portions arranged concentrically in the optical axis direction, the lens driving device for moving the lens holding member in the optical axis direction is small and lightweight. In addition, it is possible to make the lens holding member magnetically stationary at a predetermined position without providing a special lens holding member fixing mechanism.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view that best represents the features of the present invention, and FIG. 2 is a horizontal cross-sectional view taken along the line AA of FIG. 1, in which 1 is a lens for moving in the optical axis direction, and 2 is a movement. A lens holding member that holds the lens 1 (hereinafter referred to as a lens frame)
It is made of a magnetic material and is magnetized in the radial direction.
The lens frame 2 is a guide member fixed to the lens barrel 6 by being arranged in parallel with the optical axis 5 by a sleeve 2a formed on one side in the optical axis direction and a notch recess 2b formed on the other side. It is supported by the guide bars 3 and 4 so as to be movable in the optical axis direction.

A yoke 8 having a coil 7 is arranged concentrically around the lens frame 2 and is fixed to a lens barrel 6. The coil 7 and the yoke 8 are integrally bonded and fixed by adhesion or the like.

With the above structure, since the lens frame 2 generates a magnetic field in the radial direction, an electromagnetic force is generated by passing a current through the coil 7, and this electromagnetic force acts on the lens frame 2 to cause the lens to move. The frame is slid along the guide bars 3 and 4 in the optical axis direction.

As shown in FIG. 3, a plurality of concentric circular grooves 8a are arranged side by side in the optical axis direction on the inner peripheral surface of the yoke 8, so that a position where the magnetic attraction force works stably occurs.
In this embodiment, three grooves 8a are formed.
The position indicated by is one magnetic stable point.

With this structure, when no electric power is supplied to the coil 7 and no force is applied to the lens frame 2 in the direction of the optical axis, the special magnetic holding force for fixing the lens holding frame is obtained by the magnetic attraction force. It is possible to automatically hold the lens frame 2 at a predetermined stationary position without providing the above.

Although the concentric circular groove 8a, that is, the concave portion is formed in the above embodiment, the same effect as that of the above embodiment can be obtained by forming a band-shaped convex portion instead of the groove 8a. It is a thing.

[0012]

As described above, according to the present invention,
It has the following effects. (1) Since a speed reduction mechanism such as a gear box and a belt as in the conventional power transmission mechanism is not required, the volume and weight of the lens driving device can be significantly reduced, and the lens built-in device can be made smaller and lighter. Also, the manufacturing cost can be reduced. (2) By providing a stable point by a magnetic attraction force between the lens frame, which is the power generation part, and the yoke, the lens frame is magnetically stopped at a predetermined position without providing a special lens holding frame fixing mechanism. Can hold As a result, in combination with the above point (1), cost reduction, and size and weight reduction are possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a lens-equipped device of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part.

[Explanation of symbols]

 1 lens 2 lens holding frame (lens holding member) 3 guide bar 4 guide bar 5 optical axis 7 coil 8 yoke 8a groove

Claims (1)

[Claims] 1. A lens built-in device having a lens holding member for holding a lens and a guide member for movably supporting the lens holding member along an optical axis, wherein the lens holding member formed of a magnetic material is used. A yoke having a coil which is surrounded and arranged in a concentric circle shape, and a plurality of concave portions or convex portions which are concentrically arranged side by side in the optical axis direction on the inner peripheral surface of the yoke. Equipment with a built-in lens.