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Electroacoustic converter and electronic apparatus

An electroacoustic transducer and diaphragm technology, applied in the direction of sensors, electrical components, radio/inductive link selection and arrangement, etc., can solve the problems of sound pressure reduction, aspect ratio limitation, sound deterioration, etc.

Inactive Publication Date: 2003-04-16
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There is a problem that this asymmetry causes distortion to the driving force, resulting in deterioration of the reproduced sound
Widening the magnetic gap to avoid this phenomenon results in a reduction in the sound pressure of the reproduced sound
Therefore, when the shape of such an electroacoustic transducer is made oval or rectangular, the aspect ratio is limited.

Method used

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  • Electroacoustic converter and electronic apparatus
  • Electroacoustic converter and electronic apparatus
  • Electroacoustic converter and electronic apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] An electroacoustic transducer of Embodiment 1 of the present invention will now be described with reference to FIGS. 2 to 7. FIG. Figure 2A is the cross-sectional view of the electro-acoustic transducer, Figure 2B is the plan view of the first and second magnets, and Figure 2C is a plan view of the drive coil. image 3 is the assembly configuration diagram of this electro-acoustic transducer, and Figure 4 Indicates the flux vectors due to the first and second magnets. Figure 5 is a graph showing the relationship between the distance from the central axis 107 and the magnetic flux density in the central portion of the gap G in the radial direction. Image 6 is a graph showing the relationship between the distance from the center portion of the gap G in the vibration direction and the magnetic flux density at the position of the drive coil.

[0049]The electroacoustic transducer of this embodiment is formed as follows. A first magnet 101 and a second magnet 102 a...

Embodiment 2

[0065] Figure 8 is a cross-sectional view of the electroacoustic transducer according to Embodiment 2 of the present invention, and Figure 9 Indicates the flux vectors produced by the first and second magnets. The electroacoustic transducer of Example 2 was formed as follows. An upper case 103 and a lower case 104 are the same as in Embodiment 1, and together form a housing. A first magnet 201 and a second magnet 202 are attached to the upper case 103 and the lower case 104, respectively. The first and second magnets 201 and 202 are cylindrical, and are fixed to the upper case 103 and the lower case 104 such that their respective centers coincide with the central axis 203 . In addition, a drive coil 204 is attached to the diaphragm 205 so as to be concentric with the diaphragm 205 with respect to the central axis 203 . In addition, the periphery of the diaphragm 205 is placed between the upper case 103 and the lower case 104 to be fixed in the same manner as in Embodimen...

Embodiment 3

[0077] Figure 11 is a cross-sectional view of the electroacoustic transducer according to Embodiment 3 of the present invention, and Figure 12 is its stereogram. The electroacoustic transducer of this embodiment is formed as follows. First and second yokes 303 and 304 are provided around the first and second magnets 301 and 302 . The first and second yokes 303 and 304 are made of a magnetic material such as iron. Then, the first and second yokes 303 and 304, the upper case 305 and the lower case 306 form a casing in the form of a bracket. In addition, a diaphragm 308 with a drive coil 307 is held in the central portion of the housing so that the diaphragm can vibrate freely. An arcuate edge 309 is provided in the outer peripheral portion of the diaphragm 308 . The first and second magnets 301 and 302 are cylindrical and made of neodymium magnets whose energy product is, for example, 44MGOe. In addition, the magnetization directions are opposite to each other, and in th...

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PUM

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Abstract

The present invention provides an electro-acoustic transducer and an electronic device. A first magnet is provided in an upper case and a second magnet is provided in a lower case so that these magnets face each other. These magnets are magnetized in opposite directions. A diaphragm having a drive coil is placed between these magnets. Thus, magnetic flux emitted from the respective magnets bends in a direction approximately perpendicular to the initial direction of emission of the flux. In the magnetic field, the component of the magnetic flux in the direction of radiation proportional to the driving force is dominant, and is symmetrical relative to the direction of vibration. Therefore, the sound pressure of the reproduced sound is increased and the secondary harmonic distortion caused by asymmetry of the driving force can be reduced.

Description

technical field [0001] The present invention relates to an electroacoustic converter mounted on, for example, a cellular phone or a pager, and used to generate alarm sounds, melodies, and speech sounds when a call is received, and also relates to an electroacoustic transducer incorporating such an electroacoustic transducer inside. Converter electronic devices such as cellular phones, PDAs (Personal Digital Assistants), TVs, personal computers, car navigation systems, etc. technical background [0002] The reduction in thickness and the reduction in the amount of power consumption of electronic equipment represented by cellular phones, PDAs, etc. have been progressing, and further reduction in thickness and efficiency of electroacoustic transducers mounted on such electronic equipment are also expected. improve. Therefore, an electroacoustic transducer shown in FIG. 1 has been invented in order to achieve thickness reduction and efficiency improvement (Japanese Unexamined P...

Claims

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Application Information

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IPC IPC(8): H04R9/04H04R1/28H04R9/06H04R9/10
Inventor 薄木佐和子佐伯周二
Owner PANASONIC CORP