Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS5067632 □ · House, 杏, "" "Jo 7th October 1979 Patent Minorie Nyafuji Hideo /"-˜ 5, list of attached documents 1 ■ JP 50-E) 7632 internal office number 6 le 6555 Title of the book / invention , Magnetic circuit of electro-acoustic transducer DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of non-straight distortion in the magnetic circuit of an electroacoustic transducer. . Usually, as shown in FIG. 1 of this type of electroacoustic transducer, for example, dynamic speaker (2) L1, a center pole (2) is disposed at the center position of the yoke (1) and the outer periphery of the yoke (1) Magnet (3) and yoke play) (4)? Place the voice coil (6) in the gap (6) between the center pole (2) and the yoke plate (4) and communicate it with the cone (8) with the bosu cons coil 'bobbin (7) The causes of non-linear distortion in the electroacoustic transducer can be roughly divided into mechanical and electrical systems. The present invention improves the latter nonlinearity due to the electrical system. 2.) due to the magnetic non-linearity of the magnetic circuit in close proximity to the scoil (6), the yoke plate (4) and the center pole (2). That is, the voice coil (6) causes the cone (8) to vibrate approximately in proportion to the current as the signal current flowing therethrough interacts with the DC magnetic field of the magnetic circuit. However, to be precise, the amplitude of the vibration of the voice coil (6) is not in direct proportion to the current value as the voice signal. This phenomenon is caused by the ferromagnetic material of the gap (5) in which an AC magnetic field generated by the AC current of the voice coil (6) approaches the coil (6), that is, the yoke (1) as a magnetic circuit. Normally, the gap density (5), the yoke plate (4) and the magnetic flux density EndPage: 1I of this part. In order to increase the efficiency of the speaker, ferromagnetic materials such as soft iron 1 are used. Therefore, the magnetization curve of the magnetized ferromagnet becomes a minor rou 101 non-linear about the bias of the DC magnetic field. For this reason, the voltage and the current of the voice coil 13-05-2019 1 'cell (6) are in a proportional relationship in which the nonlinear magnetization curve is J strained in a non-linear magnetization curve. Annular non-linear magnetization curves occur due to losses due to the generation of eddy currents. Since a ferromagnetic material is a good conductor at the same time, when an alternating magnetic flux passes through this material, an eddy current is generated at that position in the direction to prevent the change of the magnetic flux. Therefore, in this case, the primary side has a nonlinear component in the actance. Further, the non-linear relationship between the voltage and the current means that a high-wave component is generated in the current in consideration of the voltage. The harmonics of the current are mostly the second and third harmonics. However, the harmonic components that actually cause problems are the second harmonic components, and the firstorder JP-A! @ 50-67632 (The harmonic component is negligible compared to the same component generated in the mechanical system. Now, the distortion component of the abovementioned current can be expressed by the following equation if it is theoretically determined and the calculation process is omitted and the conclusion is shown. Second harmonic component HD, in the end, R-") ω L j m Δ. The second harmonic component HD is included. Note that R is the resistance of the magnetic circuit amount, L is the self inductance in the circuit, and μmΔ is the so-called incremental permeability, and μmΔ ■, jm4 is a distortion component of the same dimension as μ 寓 Δ 鳳Is a virtual quantity to represent From the above equation (1), reduction of distortion of the electrical system of the electroacoustic transducer can be achieved by reducing + '/ (1) L, (2) setting R> ωL, (a),, 4 . This can be achieved by any solution of reducing s □ 6. The present invention provides an effective specific means corresponding to the solution method (3) among the means described above. Conventionally, as a specific example of this type of method, as shown in FIG. 3 and FIG. 3, the cross-sectional area of the surrounding magnetic material facing the voice coil (6), specifically, the center pole (2) Reduce the magnetic flux density of that part, ie, raise the operating point, bring it close to 1 sum 'q, reduce Q, and consequently reduce the voice coil distortion. The However, in these methods, the center pole (2) portion is structurally required to be cut, and a considerable increase in manufacturing cost is inevitable. Moreover, the conventional speaker (6) shown in FIG. 2 has a special cross section as a seat ring between the gap (5) removed from the vibration position of the voice coil (6)! Is a structure in which the short-circuit cap (9) is interposed, so that bending of the short-circuit cap (9) is difficult, and since it is out of the position of the voice coil (6), a sufficient reduction effect is not expected And the range of vibration of the voice coil (6), that is, the amplitude is limited. In addition, the conventional speaker shown in FIG. 3 is a structure in which a V-shaped copper cap a1 is fitted on the inner and outer peripheral wall surfaces of the Yanter ball (2), so that it is expensive. In order to obtain the reduction effect, the lateral vibration of the voice coil (6) is limited, and strict accuracy is required at the time of assembly, and in order to secure the specified gap (5), the presence of the copper cap αQ is required. As a result, the diameter of the center ball (2) is reduced, and the magnet (3) is sufficiently reinforced to obtain the necessary magnetic flux density. 13-05-2019 2 Furthermore, complicated processes such as processing of the above-mentioned conventional speakers (in the case of a conductive ring (9) (g) as a short ring) and fitting of the same to the center ball (2) are required. There is a drawback to Therefore, the present invention is developed in consideration of the above-mentioned drawbacks and problems in EndPage: 2, and the technical means disclosed herein greatly contributes to the improvement of the non-linearity in the magnetic circuit of the speaker. Above--will facilitate the 'design near gap position as compared to the exemplary prior art. The magnetic circuit of the electro-acoustic transducer according to the present invention is a magnetic circuit in a position opposite to the 1.7 ′ voice coil, a magnetic circuit of the following outer peripheral surface or yoke, a phase or a center pole and yoke. A material characterized by using a material having a saturation magnetic flux density equal to the magnetic flux density of that portion on the inner and outer peripheral surfaces is characterized in that the magnetic circuit of the present invention will be described below with reference to FIG. . In the figure, the same reference numerals as in FIG. 1 denote the same members, and the pole piece (-a) portion of the center pole (2) facing the voice coil (6) is equal to the magnetic flux density of this portion. A material having a saturated 'magnetic flux density' is used. However, 1) considering the permeance of this structure, i) permeance of gap 2P self-P, = ·················· · · · · · · · · (scan) t However, Af = cross-sectional area Lt = width of the gap of the gap) around the gap permeance:, 2P. Co P, = 0 s co-gD + · · · · · · · · · · ························· (2)) 1) above, except for the l) Permeance 2 PT (, P ++, 2 P snow) Therefore, the leakage coefficient f is = p ·························· ···· - ········· (3) P and however, the magnetic flux passing through the Am = magnet cross-sectional area center pole outside the local then the magnetic field voice coil generates exert the Borupi 3, current Assuming that the average diameter of the strained portion is D-s (≠ DP) and its thickness t-t, the magnetic flux density on the diameter D ′ ′ P reaches saturation. As a result, svmA @, swhl is small, and the distortion component of the current flowing through the voice coil is small. In addition, since the magnetic flux obtained by the above equation (5) is actually focused on the center ball via another magnetic path, it is larger than the value obtained by the equation (5), (6) Saturation is sufficient if B 'of the formula and BQ of the material are approximately equal. By the way, in the embodiment shown in the second drawing, as a specific example, 7% permalloy (, 71% Ni 7 residual Fe, Mo) in the pole piece portion of the center pole. Using Coetc), this effect is classified as first class strain resistance, and compared with the conventional Subei in Figure 1 as shown in the graph of the characteristics in Figure 5. I got The admittance curve of the ponne coil of the graph is the in of the voice coil. It supports the decrease of the inductance L. Also, the harmonic distortion curve clearly shows that the present invention is improved as compared to the prior art. Incidentally, the measurement circuit of this experiment is as shown in FIG. The measurement conditions are RO> measured point 2, and in addition to the above embodiment, the voice coil (6) and the entire upper surface of the center port-(2) facing each 13-05-2019 3 other or the yoke plate (4) Alternatively, a material having a once-accumulated flux density equal to the flux density of that portion may be used. As described above, the present invention can be easily put into practical use with a partial configuration 11 that does not limit the amplitude of the voice coil, and can reduce the nonlinearity of the magnetic circuit without reducing the magnetic flux density of the magnetic circuit cap. If you try to reduce it now, you will have the effect of making a difference. FIGS. 1 to 3 are a conventional example End page: 3 as a conventional example and FIG. 3 are cross-sectional views of the main part of a conventional speaker by distortion improvement. Fig. Q is a cross-sectional view of an essential part showing an embodiment of the present invention. FIG. S is a graph showing characteristics of the magnetic circuit according to experimental measurement results, and FIG. 6 is a measurement circuit diagram. /・・・・・・・・・ヨーク2−0−8−1. −に7. - Bohr 3 ' "6 ......... voice coil - patent applicant Sony Corporation representative patent attorney Akira Koike EndPage: 4 first 8m6. Other than the above inventor Seta ξ ξ Bay (1) Address Setagaya-ku, Tokyo, Japan 211 8-8 Fukuda 4 power name Fuku 1) Yu procedure correction (voluntary) Showa & Jan. 30, 9th Secretary of Patent Office 粛Fuji Hide Longitudinal 1, Display of the case-Sum 48 years Patent ai 116 472 No. 2, Title of the invention 2, Name of the invention Magnetism of the electric-toelectricity converter-Path 3, Person who makes correction Related patent applicant 1 Name representative Akio Morita number 0 agent , Magnetic circuit of electro-acoustic transducer 6, the date of correction instruction Spontaneous 6, subject of 1111 only subject "−-detailed description of the invention of the book-Ma", the contents of correction (two 1) on page 11 of the second line of the specification "gap (5) Correct the ferromagnetism of sI, which forms the Jtr gap (5). (Two 2) Circular ··· eO loss occurs in line 9 to line 10 of the specification. Jt-1 'jlJ divide. (Mar. 3) Correct the "conductor Jtr conductor" of the specification, page 3, line 11. (? -1 Correct the 11th "calculation course" on page 2 of the specification into "calculation process". (? 5) The name which corrects as follows the specification of the 9th page 2nd line. EndPage:5(? -6) Correct rRo> Measured in the specification, page 10, line lK4, to "RO <Measured". JP 50-67632 (6) EndPage: 6 13-05-2019 4
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