Patent Application
20070108847
The present invention relates to a cylinder-like electromagnetic motor, and more particularly to an electromagnetic motor that has an actuating structure similar to that of a cylinder and provides the same function as a voice coil motor, but has less components, smaller volume, and simpler structure than the voice coil motor.
A voice coil motor (VCM) has the advantages of small volume, low power consumption, accurately actuated displacement, and low price, and is very suitable for use as a short-distance actuator in many electronic products, such as the vibrating motor for a mobile phone, the vertical displacement actuator of a magnetic head or an optical pickup, the auto-focusing actuator for a camera, etc.
When the coil 130 is supplied with a current to produce a magnetic field, the lens holder 120 and the four magnets 115 mutually repulse or attract to thereby produce a push force against the lens holder 120. Since the lens holder 120 is supported by the spring pieces 135, it is displaced forward or backward in the outer frame 110 by the push force.
The conventional voice coil motor has a relatively large overall volume and includes a lot of components that involve complicate assembling, and therefore requires increased manufacturing cost.
It is therefore tried by the inventor to develop an improved cylinder-like electromagnetic motor to overcome the disadvantages in the conventional voice coil motor.
A primary object of the present invention is to provide a structurally new cylinder-like electromagnetic motor that has reduced components and accordingly reduced overall volume to largely decrease the material and assembling cost of the motor.
Another object of the present invention is to provide a structurally new cylinder-like electromagnetic motor that has simplified structure and lowered power consumption, and operates in an even more active and rapid manner.
To achieve the above and other objects, the cylinder-like electromagnetic motor of the present invention includes a base having a closed-bottom central hole; a cover connected to the top of the base; a spring piece located between the cover and the top of the base; a holder movably received in the central hole of the base; a magnetic element fitted to a bottom of the central hole of the base to locate below the holder; an electromagnetic element fitted below the magnetic element. Due to an electromagnetic field effect between the magnet element and the electromagnetic element, the holder located above the magnetic element is pushed forward or backward in the base.
The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein
Please refer to
The spring piece 20 is located between the cover 30 and the top of the base 10, and is provided at predetermined positions with a plurality of curved narrow openings to be divided into a movable inner portion and a fixed outer portion. The movable inner portion of the spring piece 20 is screwed to the holder 40, and the fixed outer portion of the spring piece 20 is screwed to the top of the base 10. The holder 40 is movably supported in the central hole 11 of the base 10 due to the spring piece 20 that is connected at the movable inner portion to the holder 40 and at the fixed outer portion to the base 10. The holder 40 is internally threaded for a lens 125 to screw thereinto. Since the spring piece 20 is actually a plate spring, it provide relatively good elasticity and restoring force, enabling the holder 40 to have a large moving distance relative to the base 10.
Both the spring piece 20 and the cover 30 are provided with a central hole corresponding to the central hole 11 on the base 10, and the spring piece 20 is preferably mounted on and around a top peripheral area of the holder 40, so that the lens 125 may be screwed into the holder 40 via the central holes of the cover 30 and the spring piece 20.
From a comparison of
The electromagnetic motor of the present invention applies an actuating principle different from that of the conventional voice coil motor. In the voice coil motor, fixed magnets are located around an inner movable coil to produce a magnetic field and accordingly an actuating force. However, in the present invention, a fixed electromagnet is located below a movable magnet to produce an electromagnetic field and accordingly a forward push force or a backward attraction force, just like the motion of a cylinder in an automobile to produce power at the bottom of the cylinder.
The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.
