JPS60100900A - Edgeless speaker - Google Patents

Abstract

PURPOSE:To prevent the increase of higher harmonic distortion with easy con- struction by placing a air current change member in the front direction of the peripheral clearance of a vibration member. CONSTITUTION:A flange 8 is protruded and installed from the front edge to the inside of a forward opening part 6 of a frame 4. The opening diameter of the frame 4 is made smaller to an extent than that of the opening part 6 by the flange 8. A clearance 25 is formed between the outer circumference and the opening part 6 of a diaphragm 24. When the diaphragm 24 vibrates, the empty air current with reverse phase to the vibration direction of the diaphragm 24 occurs at a clearance 25, but, the air current is prevented from being propagated in the forward direction by itself in the forward direction of the clearance 25. As such, since the empty air current flowig at the clearance 25 is changed for its flow direction with the flange 8, especially higher harmonic distortion at the low frequency range can be decreased and the excellent sound pressure-frequency characteristics can be obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a novel edgeless speaker.

For more details, how to create a simple 4+9, especially in the bass range? It is an object of the present invention to provide a new edgeless speaker that can produce low frequency harmonic distortion and obtain excellent sound pressure-frequency soft characteristics.

BACKGROUND TECHNOLOGY AND PROBLEMS Edgeless speakers, that is, members that generate sound waves by vibrating, such as so-called cones or flat diaphragms (hereinafter referred to as "vibrating members J"), are supported by cabinets or cabinets. It is known that one of the causes of sound distortion or disturbance in a speaker which is vibably supported by a support called an edge with respect to a frame is the operability of the edge.

In other words, in an edged speaker, the edge operates while deforming in accordance with the vibration of the vibrating member, but this movement is caused by the vibration of the vibrating member, which changes in accordance with changes in the audio frequency, which varies over a very wide range. It is extremely difficult to achieve accurate tracking. For example, as the audio frequency decreases, the amplitude of the vibrating member increases, so the amount of edge deformation also increases, but as the amount of edge deformation increases, the direction in which the edge is deformed follows the vibration direction of the vibrating member. This causes the vibration to deviate from the linear direction, which disturbs the accuracy of the vibration of the vibrating member.

Also, for example, as the audio frequency increases, the amount of vibration of the vibrating member increases, but the edges will not be able to move in accordance with such frequency.6 In other words, the movement of the vibrating member and the movement of the edge will be different. The behavior of the edges, such as being out of phase, acts as a vibration disturbance on the vibrating member, which causes distortion or disturbance of the sound.

Therefore, various improvements have been attempted to improve the operability of the Edge speaker.
Even so, it has not been possible to sufficiently eliminate the distortion and disturbance of the sound as described above.

In order to solve these problems of speakers with edges, speakers without edges, that is, edgeless speakers, have recently come into use.

FIG. 1 shows an example a of such an edgeless speaker.

In the figure, b is a frame opened toward the front, and the front opening of frame b is attached to the front panel part d of the cabinet C. The yoke is shaped like a letter, and the front surface of the balk e is attached to the rear surface f of the frame b. A pole g is made of a magnetic material and protrudes forward from inside the rear part of the yoke e, and its tip is located in the center of an opening formed in the front face of the yoke e.

Reference character i is an opening formed in the rear part f of the frame b, and this opening i is formed approximately concentrically with the opening of the yoke e and is larger than the opening.

Reference character j denotes a diaphragm mounting body, whose front part is formed into a substantially conical shape opening toward the front opening of the cabinet c, and whose rear part is formed into a substantially cylindrical shape. k indicates the cap portion formed in a substantially cylindrical shape. A diaphragm t formed in a substantially disk shape is attached to the front opening of the frame j, and the diaphragm 1 and the front opening of the frame b are not connected. Further, the rear end of the cap part is located between the pole g and the opening of the yoke e.Therefore, the rear end of the cap part is such that the tip of the ball g is located on the inside and the tip of the ball g is located on the outside. The opening side of the yoke e is located at . m is wound around the rear end of the cap portion, that is, the outer peripheral surface of the portion located between the ball g and the opening of the yoke e. It is a voice coil, and a sound current is passed through the voice coil m.n is an annular protrusion formed on the inside of the rear part f of the frame b, centered on the opening center of the opening part i.
Ru. 0 and P are dampers, which are arranged apart from each other in the front-rear direction, their respective outer ends supported by the protrusions n, and their respective inner ends fixed to the outer circumferential surface of the gap portion. ing.

Although the cabinet c is not shown in its entirety, it is formed into a substantially rectangular box shape with the front panel d as the side supporting the frame b (see Figure 2). .

Thus, when a voice current is passed through the voice coil m, the voice coil m is vibrated in accordance with the amplitude and frequency corresponding to the frequency of the voice current. And this voice coil m
The vibrations cause the handle j and the diaphragm t to vibrate, and the vibrations of the diaphragm t generate sound waves.

In this way, in edgeless speakers, the vibrating member is not directly connected to the cabinet or the frame supported by the cabinet, so the vibrating member can vibrate in accordance with the frequency of the audio current with high precision, and the amplitude The vibration frequency will not be disturbed. Therefore, the sound distortion and disturbance caused by the edges of the above-mentioned edged speaker do not occur.

However, edgeless speakers have a new problem due to the fact that they do not have edges. This problem will be explained with reference to FIG.

In the figure, C is a cabinet, and cabinet C
The portions other than the opening q formed in the front panel d to which the above-mentioned speaker a is attached are sealed. r is the gap between the opening q and the outer periphery of the diaphragm I, and the width of this gap r is usually about 1 mm (in the case of an edged speaker, there is a gap between the periphery of the vibrating member and the cabinet). Since it is connected to the opening q (specifically via the frame) by an edge, it does not have such a gap r.

Therefore, as mentioned above, when a sound current flows through the voice coil m, the diaphragm vibrates in the front-rear direction, that is, in the direction shown by the arrow in Fig. 2. At this time, air is generated in the gap r. flows. The direction of this air flow is opposite to the direction of vibration of the diaphragm t. That is, when the diaphragm t moves forward (in the direction shown by the solid line arrow), the air outside the cabinet C flows through the gap r into the cabinet c, and conversely, when the diaphragm t moves backward (in the direction shown by the broken line arrow) ), the air inside the cabinet C flows through the gap r and is pushed out of the cabinet C. That is, in the gap r, air vibrations occur in substantially the opposite phase to the vibrations of the diaphragm t. This means that a sound source other than the diaphragm t is located in the gap r.
This means that it occurs in the same way, and is the cause of distortion. Particularly in the bass range, since the amplitude of the diaphragm increases, the amount of air passing through the gap r also increases, and air vibrations that are in opposite phase to the vibration of the diaphragm t described above become significant. Then, the sound waves generated by the vibration of the air passing through the gap r interfere with and disturb the sound waves generated by the vibration of the diaphragm 1, thereby causing significant iWt harmonic distortion.

The broken line graph shown in FIG. 8 shows an example of the sound pressure-frequency characteristic of a conventional edgeless speaker, where the curve S shows the second high frequency distortion, and the curve t shows the third high frequency distortion.

Note that [ju indicates the fundamental wave generated by the edgeless speaker.

As shown by the curves S and t, in the conventional edgeless speaker, significant distortion occurs in the sound pressure level at frequencies in the bass range, particularly at frequencies below about 100 hertz.

Purpose of the Invention The present invention has been made in view of the above-mentioned problems with conventional edgeless speakers.It is possible to reduce harmonic distortion, especially in the low frequency range, with a simple structure, and to achieve excellent sound pressure. - It is an object of the present invention to provide a new edgeless speaker that can obtain frequency characteristics.

R Summary of the Invention In order to achieve the above-mentioned object, the edgeless speaker of the present invention includes, in front of the gap around the vibrating member that generates sound waves,
The present invention is characterized in that an airflow changing member is disposed to direct the flow direction of air passing through the gap in a direction different from the vibration direction of the vibration member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Details of the edgeless speaker of the present invention will be explained below according to embodiments shown in the drawings.

First Embodiment FIGS. 3 and 4 show a first embodiment of the edgeless speaker of the present invention.

In the figure, reference numeral 2 indicates the front panel of the cabinet, and a speaker mounting opening 3 is formed in the approximate center of the front panel 2.Although the cabinet is not shown in its entirety, it has a substantially rectangular parallelepiped shape. It is box-shaped (see Figure 5).

4 is a frame whose front end is attached to the front panel 2 of the cabinet. The side surface 5 of the frame 4 increases in diameter toward the front end, and is formed into a substantially trapezoidal shape when viewed from the side. Reference numeral 6 denotes a front opening formed at the front end of the frame 4, and is formed in an annular shape with a certain width in the front-rear direction.

Reference numeral 7 denotes a mounting flange that is formed at a connecting portion between the front opening 6 and the side surface 5 so as to protrude outward. Thus, the front opening 6 of the frame 4 is fitted into the speaker mounting opening 3 formed in the front panel 2 of the cabinet, and
The mounting flange 7 is fixed to the front panel 2 by suitable fixing means while being engaged with the inner opening edge of the receptacle opening 3.

Reference numeral 8 denotes a flange that protrudes inward from the front end of the front opening 6 of the frame 4, and the diameter of the opening 1'' in the n11 direction of the frame 4 is larger than the diameter of the front opening 6 due to this flange 8. It has been made smaller to some extent.

9 is a back plate of the frame 4, and an opening 10 is formed in the center thereof. Reference numeral 11 denotes an annular protrusion formed on the back plate 9 at a position close to the outer periphery of the front surface and protruding forward. 12.12,... is the side llT of frame 4
This is a notch hole formed in the first part 5.

Reference numeral 13 denotes a yoke formed in a substantially U-shape when viewed from the upper blade, and a plate 14 made of a magnetic material is integrally attached to the front end surface of the yoke 13. 15 is plate 1
This is the insertion hole formed in the center of the frame 4, and the opening formed in the back plate 9 of the frame 4 marked +ii+
The zero diameter is made larger than the diameter of the insertion hole 15 of the plate 14. The yoke 13 is inserted into the insertion hole 1 of the plate 14.
5 and the opening 1o on the back side of the frame 4 are fixed to the back plate 9 of the frame 4 so that they are coaxially positioned.

16.16, . . . are the screws that attach the yoke 13 to the frame 4. That is, the yoke 13 is fixed to the frame 4 by screwing the plate 14 to the back plate 9 of the frame.

Reference numeral 17 denotes a U-shaped intermediate portion of the yoke 13, that is,
This is a magneto that stands upright from approximately the center of the front of the back toward the front. A pole piece 18 having a diameter larger than that of the magnet 17 is fixed to the tip of the magnet 17, and the outer peripheral surface of the pole piece 18 is inserted into the insertion hole 15 of the plate 14. It is located at a certain distance from the inner circumferential surface of 15.

Reference numeral 19 denotes a diaphragm mounting body having a front portion 20 formed in a substantially conical shape and a rear portion serving as a cap portion 21 having a substantially cylindrical shape. A flange 22 projecting outward is formed at the front end of the front part 20 of the diaphragm mounting body 19, and the rear cap part 21 is formed into the insertion hole 1 of the plate 14 described above.
The distal end 68 is passed between the inner circumferential surface of the pole piece 5 and the outer circumferential surface of the pole piece 18 and extends to approximately the center of the pole piece 13 . Therefore, the front part of the magnet 17 and the pole piece 18 are inserted into the cap part 21, and the intermediate part of the cap part 21 is inserted into the outer peripheral surface of the pole piece 18 provided at the tip of the magnet 17. It is positioned between the inner circumferential surface of the hole 15 and the two members apart from each other.

A voice coil 23 is wound around the outer periphery of the intermediate portion of the cap portion 21, and the voice coil 23 is connected to an audio current output portion of an audio circuit (not shown).

Reference numeral 24 denotes a diaphragm formed in a substantially disk shape, and its outer circumferential portion is attached to the flange 22 of the diaphragm mounting body 19, so that it becomes integral with the mounting body 19. There is. The diaphragm 24 is disposed in the front opening 6 of the frame 4 such that its outer peripheral edge is spaced apart from the inner peripheral surface of the front opening 6. Therefore, a gap 25 is formed between the outer peripheral edge of the diaphragm 24 and the front opening 6 of the frame 4. Although the width of this gap 25 is not absolutely specified, it is generally about 1 mm.

However, in front of the gap 25, the frame 4 described above
The flange 8 formed at the front end of the front opening 6 is disposed, so that the flange 8 extends in the front of the gap 25 in a direction substantially perpendicular to the vibration direction of the diaphragm 24.
It will be blocked by.

26 and 27 are dampers, and the diaphragm mounting body 19 is supported by the dampers 26 and 27 so as to be arranged as described above. One damper 26 has its outer end fixed to the annular protrusion 11 formed on the back plate 9 of the frame 4, and its inner end fixed to the outer peripheral surface near the front end of the cap part 21. has been done. The other damper 27 has its outer end fixed to a damper mounting member 28 provided on the rear surface of the play plate h14, and its inner end fixed to the outer peripheral surface extending over the rear end of the cap part 21. ing. Thus, the diaphragm body 19 is supported by the frame 4 via the dampers 26 and 27 so as to be movable in the front-rear direction.

Since the voice coil 23 is placed in the magnetic field formed between the outer circumference 1rO of the pole piece 18 and the inner circumferential surface of the insertion hole 15 formed in the plate 14, the voice current is not passed through it. Then, the voice coil 23 is caused to vibrate according to the amplitude and frequency corresponding to the frequency of the voice current. The mounting body 19 and the diaphragm 24 are vibrated together with the voice coil 23, and the vibration of the diaphragm 24 causes the air in front of the diaphragm 24 to vibrate, thereby generating a sound wave with a predetermined frequency. .

Furthermore, when the diaphragm 24 is vibrated in this way, the gap 2
5, an air flow having a phase opposite to the vibration direction of the diaphragm 24 is generated, but it can be seen that this air flow is propagated forward as it is in front of the gap 25.

This will be explained in FIG. In the figure, 29 indicates a cabinet, 24 a diaphragm, and 8 a flange formed on the frame 4. As described above, when a sound current is applied to the voice coil 23, the diaphragm 24 vibrates in accordance with the amplitude and frequency of the sound current, and the vibration direction is the direction shown by the solid line arrow in FIG. On the other hand, as the diaphragm 24 is vibrated, it is generated in the gap 25.
An air flow is generated, and when the diaphragm is moved forward, the air outside the cabinet 29 flows into the cabinet 29.
When the diaphragm 24 is moved rearward, the air inside the cabinet 71-29 is forced out of the cabinet 29. However, the direction of the air flow generated in the gap 25 in this way is determined by the flange 8 formed integrally with the frame 4 in front of the gap 25.
, the direction of the flow can be abruptly changed there.

The sound pressure-frequency characteristics shown by the curves V and W in the graph of FIG. 8 can be obtained by using the mechanical speaker 1 formed in this way. Furthermore, here the curve V
indicates the second harmonic, and curve W indicates the third harmonic. As shown by curves V and W, the second harmonic distortion and third harmonic distortion occurring at frequencies in the bass range are significantly reduced compared to the harmonic distortion in conventional edgeless speakers. ing. The reason why harmonic distortion is significantly reduced in this way is that in the edgeless speaker 1 of this embodiment, the above-mentioned air flow flowing through the gap 25 is disturbed because its flow direction is changed by the flange 8. it is conceivable that.

Second Embodiment FIG. 6 shows a second embodiment L of the edgeless speaker of the present invention.
This shows A.

The difference between the edgeless speaker IA shown in the second embodiment and the edgeless speaker I in the embodiment t141 described above is that the edgeless speaker IA shown in the second embodiment is different from the edgeless speaker I in the above-mentioned embodiment t141. Only changed parts. Therefore, only the parts that are different from those in the above-mentioned Embodiment ① will be explained, and the parts that are not different will be explained by giving the same reference numerals as those in the Embodiment 1 above. omitted. This point also applies to the third embodiment' to be described later. In FIG. It is bent at almost a right angle.

33. 33, ψ·- are mounting legs protruding from the rear surface of the circular band portion 31. Thus, the airflow changing member 30 has a speaker mounting opening 3 formed in the front panel 2 of the cabinet such that the circular band portion 31 thereof is disposed in front of the gap 25.
It is attached to the periphery of the opening.

As a result, the space in front of the gap 25 is bent outward from the opening edge of the front opening 6 of the frame 4 at a substantially right angle. Therefore, the direction of the airflow passing through the gap 25 caused by the vibration of the diaphragm 24 is suddenly changed to a direction different from the direction of vibration of the diaphragm 24.

Note that the airflow changing member 30 may be formed integrally with the front end portion of the frame 4.

Third Embodiment FIG. 7 shows the third embodiment IB of the edgeless speaker of the present invention.
This shows that.

In the figure, numeral 34 is a front net formed in the shape of a circular, approximately shallow dish, and has a circular band portion 3 having a certain width on the outer peripheral surface.
There are many holes 36.
is formed. The aperture ratio of the holes 36, 36, ◆, .

Thus, the 1111-sided net 34 is attached to the opening periphery of the speaker mounting opening 3 formed in the front panel 2 of the cabinet, with the circular band portion 35 being disposed on the liJ side of the gap 25. That is, the circular band portion 35 acts as an airflow changing member.

As a result, the direction of the space in front of the gap 25 is changed inward from the opening edge of the front opening 6 of the frame 4 in a substantially perpendicular direction. .36, . . . are located. Thus, the sound waves generated by the vibration of the diaphragm 24 are propagated in a predetermined direction through the holes 36, 36, . . . of the front net 34. Further, the flow direction of the airflow passing through the gap 25 is changed to a direction different from the vibration direction of the diaphragm 24.

In each of the embodiments described above, the front of the gap around the diaphragm is entirely covered by the airflow changing member, but in the present invention, the airflow changing member is placed in front of the gap and covers the gap. Any shape is sufficient as long as it allows the flow direction of the passing air to be directed in a direction different from the vibration direction of the diaphragm.

Effects of the Invention As is clear from the above description, the edgeless speaker of the present invention has an L vibrating member that directs the air flow direction through the gap in the +tfJ direction of the gap around the vibrating member that generates sound waves. It is characterized by disposing an airflow changing member that directs the airflow in a direction different from the vibration direction of the airflow.

Therefore, according to the present invention, the direction of air flow passing through the gap around the vibrating member is disturbed by being directed in a direction different from the diaphragm 0-appealing direction, so the gap no longer functions as a sound source and the vibration It is possible to prevent harmonic distortion of sound waves generated by the member from being increased.

Moreover, in the present invention, an increase in harmonic distortion can be prevented by an extremely simple structure in which the airflow changing member is placed in front of the gap around the vibrating member.
There is no need for the speaker to become large or heavy, and the cost does not increase.

Therefore, according to the present invention, there is provided a novel edgeless speaker that can reduce harmonic distortion particularly in the low frequency range with a simple structure and can obtain excellent sound pressure-frequency characteristics. be able to.

In each of the above-mentioned embodiments, an edgeless speaker in which the vibrating member is a flat diaphragm is shown, but the present invention can be similarly applied to an edgeless speaker in which the vibrating member is formed in a cone shape. Of course it can be done.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view showing an example of a conventional edgeless speaker, Fig. 2 is a conceptual diagram for explaining the air flow accompanying the vibration of the diaphragm in the edgeless speaker shown in Fig. 3 and 4 show the first embodiment of the edgeless speaker of the present invention, FIG. 3 is a horizontal sectional view, and FIG.
The figure is a perspective view of the frame, FIG. 5 is a conceptual diagram for explaining the flow of air accompanying the vibration of the diaphragm in the edgeless speaker shown in FIG. 3, and FIG. A partially cutaway plan view showing a second embodiment, FIG. 7 a partially cutaway plan view showing a third embodiment of the edgeless speaker of the present invention, and FIG. 8 a conventional edgeless speaker and the present invention. FIG. 2 is a graph diagram showing sound pressure-frequency characteristics of the edgeless speaker. Explanation of symbols l, IA, IB - fist/edgeless speaker. 8...Airflow modification member, 24.Φ and vibration member, 25.
... Gap, 30... Airflow changing member, 35... Airflow changing member Figure 1 Figure 2 Figure 3 Figure 4 Figure 4 Figure 7

Claims (1)

[Claims] An edgeless speaker characterized in that an airflow changing member is disposed in front of a gap around a vibrating member that generates sound waves to direct the flow direction of air passing through the gap in a direction different from the vibration direction of the vibrating member.