JP3025025B2 - Handset - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for generating sound pressure in a closed cavity, particularly to a telephone receiver, a headphone, and an earphone.

[0002]

2. Description of the Related Art In a conventional acoustic device which generates a sound pressure in a closed cavity such as a telephone receiver, a headphone or an earphone and converts an electric signal into a sound signal, various kinds of diaphragms or diaphragms are vibrated by the electric signal. And the sound wave is brought into the closed cavity. For example, in a telephone handset of a type called an electromagnetic converter, a constant attractive force is applied to an armature formed integrally with a diaphragm by a magnet, and a magnetic flux proportional to an input signal is superimposed on the magnet. ,
By changing the suction force, the vibration plate is caused to vibrate. In addition, the electromagnetic earphone has the same principle that the sound wave generated in the closed cavity is sent directly into the ear, and the electrodynamic earphone and the electrodynamic headphone are directly connected to the voice coil provided in the magnetic field. A vibrating cone, which is a conical diaphragm provided, generates a sound wave in the closed cavity. In addition, a piezoelectric earphone has a configuration in which a diaphragm is vibrated by using a piezoelectric element such as Rochelle salt.In an electrostatic headphone, a capacitance is formed between a diaphragm and a fixed electrode, and a DC bias is applied to the capacitance. In addition, an electric charge is accumulated on the vibrating membrane, an AC input voltage is applied thereto to generate an AC electric field, and the electric field vibrates the vibrating membrane by Coulomb force generated in the electric charges on the vibrating membrane. Further, the electret headphones have a configuration in which electric charges are induced on the vibrating membrane by an electret film adhered to a fixed pole by the principle of electrostatic induction, and the vibrating membrane to which an AC electric field is applied vibrates.

[0003]

SUMMARY OF THE INVENTION
Both headphones or earphones are designed to generate sound pressure in a closed cavity using a diaphragm or diaphragm with an electric signal, and faithful reproduction of the sound pressure generated by vibration of this diaphragm or diaphragm. The gender is this kind of telephone handset,
It is important for headphones or earphones. In addition, the sound wave generated in the closed cavity is reflected on the inner wall surface of the closed cavity, and the reflected sound wave interferes with the generated sound wave. Furthermore, the sound waves thus generated in the closed cavity are
It has the disadvantage that it causes vibrations of the telephone handset, headphone or earphone structures themselves, and from these structures sound waves of a waveform specific to the structures in the closed cavity.

[0004] From this point, the sound pressure generated from the diaphragm or the vibrating membrane is prevented from having directivity, and the generated sound wave is prevented from being reflected on the inner wall of the closed cavity of the receiver. Preventing the generation of vibrating sounds has been considered important in the reproducibility of speech in a receiver.
The handset according to the present invention, in view of the inconvenience in such a conventional handset, makes the generated sound wave in the diaphragm or the vibrating membrane non-directional, and furthermore, the sound wave reflection in the closed cavity of the handset and the structure of the handset. The purpose of the present invention is to provide a handset that prevents generation of a vibrating sound.

[0005]

SUMMARY OF THE INVENTION The present invention achieves such an object by providing at least all or part of the surface of a diaphragm or the surface of a diaphragm of a receiver which generates sound pressure in a closed cavity. The handset is covered with a resin film 2 and has a structure in which trace holes 4 for removing gelatin powder 3 belonging to a range in which the number average molecular weight is smaller than 8,500 are provided on the resin film 1. According to a second aspect of the present invention, the receiver is configured as a telephone receiver, and in the third aspect of the present invention, the receiver is configured as headphones.
In the invention, the receiver is configured as an earphone.

[0006]

A resin film 2 having a trace hole 4 for removing gelatin powder 3 having a number average molecular weight of less than 8,500 is formed on the surface of a component constituting a receiver, particularly a diaphragm or a diaphragm. Therefore, if this part is a vibrating or resonating part in the closed cavity of the handset,
Due to the generated vibration, a non-directional sound wave is generated.
In addition, the surface of the component constituting the handset, particularly the component in the closed cavity, is provided with the trace hole 4 for removing the gelatin powder 3 belonging to the range where the number average molecular weight is smaller than 8,500. The sound waves generated in the vibrating membrane are eliminated on the surface of the component constituting the closed space of the receiver, and the amount of reflection is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of a receiver according to the present invention will be described below. The receivers targeted here are known telephone handsets, known headphones and known earphones, and the headphones include electrodynamic headphones, electrostatic headphones, electret headphones, and the like. Electromagnetic earphones, electrodynamic earphones, piezoelectric earphones, and the like are included. In the handset according to the present invention, on the premise of the structure of such a conventionally known handset, all or a part of the inner wall surface of the closed cavity of the handset and the surface of the component 1 in the closed cavity are made of resin. The resin film 2 has a number average molecular weight of 8,500.
In this configuration, the trace holes 4 for removing the gelatin powder 3 belonging to a smaller area are provided.

[0008] The portion of the handset where the resin film 2 is formed is mainly a diaphragm or a vibrating membrane, and the vibrating plate is a part 1 existing in a closed cavity having a vibrating membrane and a part forming the closed cavity. The first inner wall surface is a preferred component. Parts 1 of various handsets with such a configuration
The resin film 2 is provided so as to cover all or a part of the entire surface or a part of the surface. As the resin film 2, it is preferable to use a resin film that has good familiarity with the components 1 on which the resin film 2 is formed and does not impair the vibration characteristics of each component 1. This type of resin film 2 is preferably formed as a coating film of a synthetic resin paint, as a coating film of a synthetic resin coating solution, or as a laminate layer of a synthetic resin laminate film. Further, the coating film of the synthetic resin-based paint may be formed by any method such as a brush coating method, a spraying method, and a immersion method. When the target component 1 is a cloth or the like, a coating film may be formed by impregnating the cloth material. The coating film may be formed by a doctor knife coating method, a dipping method, or any other method. The laminate layer may be formed by separately forming a laminate film on release paper, and then forming the laminate film on the release paper by a transfer method, or by directly laminating and forming the laminate film on the surface of the component 1 without using release paper. May be. Further, it may be formed by a method of heat fusion using the laminated film or the component 1.

[0009] The resin film 2 formed over the surface of the component 1 as described above has a structure in which the number average molecular weight is less than 8,500, and the pores 4 are traces for removing the gelatin powder 3 belonging to a range smaller than 8,500. The pores 4 as removal marks formed in the resin film 2 are made of gelatin powder, particularly, having a number average molecular weight of 8,500.
It consists of trace holes from which gelatin powder 3 belonging to a smaller area has been removed. The removal trace holes 4 formed in the resin film 2 as described above are trace trace holes from which the gelatin powder 3 belonging to the range in which the number average molecular weight is smaller than 8,500 is particularly removed, so that the acoustic characteristics of the receiver are particularly improved. Good. That is, the holes 4 formed on the resin film 2 where the gelatin powder 3 has been removed have a uniform diameter and are evenly distributed, so that the receiver has good acoustic characteristics.

In order to form such characteristic pores 4, it is necessary that the gelatin powder 3 removed from the resin film 2 has a number average molecular weight of less than 8,500. Here, a gelatin powder having a number average molecular weight belonging to a range smaller than 8,500 is applied to the resin film 2 using a gelatin powder.
The reason for forming the removal trace hole 4 is as follows. That is, commercially available gelatin powder has irregularities in particle size, and there is a disadvantage that the particle size is too large. There is a disadvantage that an excessively large hole is formed in a coating film to be formed or the like, and a specific directionality is generated in the generated sound wave, or a specific reflected sound wave is generated. It has been found from many acoustic experiments that it is desirable that the gelatin powder contained in the coating film and the like formed is finer and that it is provided in a certain range.

Therefore, the present inventor mass-produced a fine gelatin powder used in a resin by using a commercially available gelatin powder using a jet mill. The pulverization using the jet mill allows the pulverized gelatin particles to be classified in the pulverization process, and is suitable for obtaining pulverized particles in a certain particle size range. However, in the pulverization of gelatin powder by dry pulverization means using this jet mill, the pulverized gelatin particles are in an aggregated state in which they are fused together, and the pulverization itself cannot be performed, or the pulverized gelatin particles bind to the inner wall surface of the pulverizer. And so on. Therefore, the inventors of the present invention made the inside of the crusher an extremely low humidity atmosphere and pulverized the gelatin powder in a state where the water content of the gelatin powder to be charged into the crusher was removed as much as possible. By the improvement of the pulverization method, pulverization and classification of the gelatin powder became possible, and pulverized gelatin particles in a fine particle size range were obtained. However, the amount of the pulverized particles obtained by the improved pulverization method using a jet mill is extremely small, and is practically meaningless at all even if it is experimentally possible. In addition, in this improved grinding method using a jet mill, water is further removed from the ground gelatin during the grinding process,
In combination with the long grinding time, the ground gelatin particles were denatured and could not be eluted with water or hot water.

Therefore, the present inventor has proposed that gelatin powder is put into a wet pulverizer such as a wet ball mill together with an organic solvent such as dimethylformamide, and the inside of the wet pulverizer is pulverized into a dry atmosphere. Tried. In the pulverization of gelatin powder using this wet ball mill, by preventing the water content at the time of pulverization of the pulverized gelatin powder from increasing, the pulverized gelatin particles can be mutually aggregated or bound to the inner wall surface of the pulverizer. Without this, efficient pulverization was achieved. However, in the pulverization of gelatin powder using this wet ball mill, the particle size of the pulverized gelatin particles is extremely irregular, and the pulverized gelatin particles having a particle size close to the input raw material powder and a fine particle having a fine particle size of less than 1.5 μm are used. There was a disadvantage that the ground gelatin particles were mixed at a certain ratio. In the pulverization of gelatin powder using such a wet ball mill, by changing the pulverization conditions, the average particle size of the obtained pulverized gelatin particles can be arbitrarily reduced. Accompanying this, the variation in particle diameter became even more remarkable, and it became clear that practical use was difficult. In particular, in the method of pulverizing gelatin powder using such a wet ball mill, it is necessary to set a longer pulverization time when eliminating large-diameter gelatin particles contained in the pulverized gelatin particles. Milled gelatin grains that do not contain large diameter gelatin grains will contain many "overmilled" gelatin grains.

The over-ground gelatin particles, particularly gelatin particles having a size of less than 1 μm, have a drawback that they cannot be eluted from the formed coating film and the like. Had difficulties in practical use. Therefore, in this embodiment, the gelatin used for the pulverization is assumed to belong to the range in which the number average molecular weight is smaller than 8,500, and the particle diameter of the gelatin powder obtained by the pulverization is made uniform and the gelatin powder is easily taken out from the resin film 2.

The average molecular weight used in the present specification is as follows:
The numerical value obtained by dividing the total mass of a molecule by the total number of molecules is used to mean the number average molecular weight. The molecular weight is the mass of a molecule expressed in a unit where the mass of C ¹² atoms is 12.

One of the practical and preferred particle sizes of the gelatin powder used in this embodiment is that the average particle size is 3 μm or more.
An average particle diameter consisting of one numerical value specified within a range of 5.5 μm ( ¹ / _1,000 mm is indicated as μm in the present specification), for example, the average particle diameter is 4.32 μm, 3.89 μm, and 4.
A gelatin powder having a particle size distribution of 44 μm and 4.77 μm is desirable. The particle size used here is measured by centrifuging sedimentation of a gelatin powder in a dispersion of gelatin powder in ethanol, and is calculated from the measured volume. Further, the average particle diameter indicates one particle diameter corresponding to a cumulative distribution of 50% by weight as an average particle diameter.

Next, a practical and preferable particle size distribution of the gelatin powder is such that gelatin powder having a diameter larger than 9 μm is effectively removed, and gelatin particles having a diameter larger than 9 μm are 10 _wt % based on the total amount of gelatin powder. % Is a preferred embodiment. Further, a practical and preferable particle size distribution of the gelatin powder is such that the gelatin powder having a particle size included in a range smaller than 1.5 μm is effectively removed, and the particle size distribution smaller than 1.5 μm is relative to the total amount of the gelatin powder. 10 gelatin powder
_In one preferred embodiment, the amount is less than _wt %.

Next, the typical gelatin powder of the present invention will be described more specifically. The gelatin powder is obtained by pulverizing and classifying gelatin having an average molecular weight of less than 8,500 by a dry pulverization method. In particular, the gelatin powder used here is obtained from a polypeptide obtained by hydrolyzing a protein derived from collagen such as commercially available gelatin (general gelatin including glue) with enzymes, acids and alkalis. It is good to pulverize the polypeptide by a dry pulverization method such as a jet mill, and the average molecular weight is 8,500.
Gelatin in the smaller range is used as the raw material for grinding.

In particular, in this embodiment, after commercially available gelatin is hydrolyzed with an enzyme, an acid, or an alkali, it is heated at about 120 ° C.
The average molecular weight sprayed from the nozzle into the hot air and dried
1,000 to 8,500 gelatin coarse powders are used. In addition, when the gelatin coarse powder to be ground has already been adjusted to an average molecular weight of 1,000 to 8,500 by hydrolysis, the gelatin coarse powder to be ground without further hydrolysis treatment is used as it is. Used.

The gelatin powder as such a raw material is pulverized using a dry pulverizing means such as a jet mill to obtain finely pulverized gelatin particles. In the pulverization of the gelatin coarse powder, a gelatin coarse powder having an average molecular weight in a range smaller than 8,500 has extremely excellent pulverizability with respect to a gelatin coarse powder having an average molecular weight in a range larger than 8,500. On the other hand, coarse gelatin powder having an average molecular weight of more than 8,500 has an extremely small amount of pulverization per unit time, and cannot be used for mass production of fine gelatin powder at low cost. The grinding characteristics per unit time of this gelatin coarse powder are better as the average molecular weight of the gelatin coarse powder to be ground is smaller, and from the viewpoint of grinding efficiency per unit time, the average molecular weight is less than 8,500. It is preferably gelatin belonging to One milling characteristic of gelatin coarse powder having a different average molecular weight is that the average molecular weight is 1,00.
100% by weight
Is 84% by weight for gelatin coarse powder having an average molecular weight of 3,000, and 80% by weight for gelatin coarse powder having an average molecular weight of 5,000.
It was 76% by weight in a coarse gelatin powder having an average molecular weight of 7,000, and 62% by weight at an average molecular weight of 8,500. From this, even coarse gelatin powder having an average molecular weight of 8,500 can be pulverized sufficiently efficiently. On the other hand, in the pulverization of a gelatin coarse powder having an average molecular weight of 10,000, when the above-mentioned pulverized amount of the gelatin coarse powder having an average molecular weight of 1,000 is assumed to be 100% by weight, it is only 28% by weight and further a gelatin coarse powder having an average molecular weight of 13,000. The amount of pulverization per unit time in pulverization is only 16% by weight of the pulverization amount of the above-mentioned gelatin coarse powder having an average molecular weight of 1,000, and none of them is suitable for practical pulverization.

Next, the fact that gelatin coarse powder belonging to the range having a small average molecular weight is more efficiently pulverized than that of gelatin coarse powder belonging to the range having a large average molecular weight is the point that gelatin coarse having a different average molecular weight is used. The average molecular weight of the gelatin coarse powder to be milled is also evident from the fact that the average molecular weight of the gelatin coarse powder to be milled is also evident from the point that the average particle size can be set low under the same milling conditions. The following is preferred. In a typical example of the average molecular weight and the average particle size, the average particle size of gelatin particles obtained by grinding a coarse gelatin powder having an average molecular weight of 1,000 is 10%.
When 0, the average particle size of the gelatin particles obtained by crushing the gelatin coarse powder having an average molecular weight of 8,500 is 110, and the average particle size of the gelatin particles obtained by crushing the gelatin coarse powder having the average molecular weight of 10,000 is 135. In addition, the average particle size of the gelatin particles obtained by pulverizing gelatin coarse powder having an average molecular weight of 13,000 is 173, and the average particle size of the gelatin particles obtained by pulverizing gelatin coarse powder having an average molecular weight of 8,500 or more is Extremely high, and from this aspect, gelatin having an average molecular weight in the range of more than 8,500 cannot be an object of the present invention.

Next, the relationship between the average molecular weight of the gelatin coarse powder to be ground and the amount of gelatin particles over 9 μm contained in the ground gelatin particles will be clarified. In one case where the coarse gelatin powder to be ground was ground and classified under the same conditions, the amount of 9 μm-over gelatin particles contained in the ground gelatin particles obtained by grinding the coarse gelatin powder was an average molecular weight of 1,000. 0 _wt % when crushing gelatin coarse powder, 1.9 _wt % when crushing gelatin coarse powder having an average molecular weight of 3,000, 3.9 _wt % when crushing gelatin coarse powder having an average molecular weight of 7,000, average molecular weight
In the case of grinding 8,500 gelatin coarse powder, which is 4.5 wt%, which is a low value, 24.9 _wt % was obtained by grinding gelatin coarse powder having an average molecular weight of 10,000, and 33.0 _wt % was obtained by grinding gelatin coarse powder having an average molecular weight of 13,000. It shows a high value of%.

As a result, gelatin particles obtained by grinding a coarse gelatin powder having an average molecular weight of more than 8,500 are not suitable for practical use because the ratio of gelatin particles having a large diameter in the gelatin particles is high. Gelatin powder 3
Is eluted from the resin film 2 using water, hot water, etc.
This is convenient for forming the trace holes 4 for removing the gelatin powder 3. Further, in the elution of the gelatin powder 3, an organic solvent having an average molecular weight of less than 80, more preferably methyl alcohol, ethyl alcohol or the like having an average molecular weight of less than 60 is infiltrated into the resin film 2, and then the resin film 2 is dissolved in water. It is preferable that the dissolution of the gelatin powder 3 makes the dissolution of the gelatin powder 3 more effective.

[0023]

The handset according to the present invention has the whole or a part of the surface of the component 1 including the diaphragm or the diaphragm, particularly,
The components in the closed cavity of the handset and the inner wall surface of the closed cavity are covered with a resin film 2, and the resin film 2 is provided with holes 4 as traces of gelatin powder 3 being eluted. The pores 4 are configured as traces of the elution of gelatin powder 3 having a number average molecular weight of less than 8,500. As a result, the holes 4 formed in the resin film 2 are fine and have a uniform diameter, and the gelatin powder 3 remaining in the resin film 2 is hardly recognized. It has a structure having fine and uniform holes 4 over the entire surface.

In addition, since gelatin powder 3 having a number average molecular weight belonging to a range smaller than 8,500 is used, the gelatin powder 3 contained in the resin film 2 can be formed easily and at low cost, and the particle size can be reduced. , And it is possible to easily and surely make the holes 4 formed in the resin film 2 uniform and fine. Furthermore,
Since the gelatin powder having a number average molecular weight of less than 8,500 is used, it is easy to take out the gelatin powder 3 in the resin film 2 formed, and the surface of the hole 4 where the gelatin powder 3 has escaped is smooth. It has the following features.
Since the surface of the vibrating part of the handset and the surface of the closed cavity to which the sound wave is transmitted have the holes 4 having a fine, uniform and smooth surface, the sound wave generated from the vibrating part is It has the feature that it is transmitted as a rather soft sound that is generated from the fine hole 4 part. In addition, sound waves generated in the closed cavity and transmitted to the inner wall surface of the closed cavity are minutely diffusely reflected by the holes 4 having uniform, fine and smooth surfaces on the inner wall surface of the closed cavity. Erasing is performed on the inner wall surface or the surface of the component in the cavity, thereby preventing generation of abnormal noise. Therefore, there is an advantage that the reproducibility of the sound in the receiver is more faithful.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part before taking out a gelatin powder.

FIG. 2 is an enlarged sectional view of a main part after taking out a gelatin powder.

[Explanation of symbols]

 1 Component 2 Resin film 3 Gelatin powder 4 Hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 7/02 D06N 7/02 H04M 1/03 H04R 1/10 101 H04R 1/10 104

Claims (4)

(57) [Claims] At least all or a part of the surface of a diaphragm or a vibrating membrane of a handset which generates sound pressure in a closed cavity is covered with a resin film, and the resin film has a number average molecular weight of 8,500. A handset having trace holes for removing gelatin powder belonging to a smaller area. 2. The handset according to claim 1, wherein the handset that generates sound pressure in the closed cavity is a telephone handset. 3. The handset according to claim 1, wherein the handset that generates sound pressure in the closed cavity is a headphone. 4. The handset according to claim 1, wherein the handset that generates sound pressure in the closed cavity is an earphone.