JPH0438633Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a headphone speaker unit for reproducing audio signals.

[Conventional technology]

Generally, a headphone as shown in FIG. 7 has been proposed. In FIG. 7, reference numeral 12 denotes a headband, and a headphone unit 13 is attached to both ends of the headband 12, and an ear pad 14 is attached to the side of the headphone unit 13 that is placed against the ear. An example of the internal structure of this headphone unit is shown in FIGS. 8 and 9. The headphone unit shown in FIGS. 8 and 9 is of an external magnetic type, and a plurality of through holes 1a are provided in a cylindrical protector 1 in the direction of contact with the ear, and a voice coil 3 is provided inside the through holes 1a. A diaphragm 2 to which a diaphragm is attached is arranged. voice coil 3
is movably arranged in a magnetic gap formed by a plate 6 and a yoke 8, and the magnet 4 is held between the plate 6 and the yoke 8. The yoke 8 has openings 8 at multiple locations.
a, from the diaphragm 2 to the back side of the protector 1,
That is, ventilation is allowed to flow in the direction opposite to the direction in which it is placed against the ear, and the terminal board 10 is fixed in contact with the back side. As shown in FIG. 9, the terminal board 10 has an opening 10a corresponding to the opening 8a of the yoke 8, and a conductive pattern 10 for relaying external wiring to the voice coil 3.
It has b. And in this opening 10a,
A breathable damping cloth 11 is attached, and the amount of ventilation from the diaphragm 2 to the back surface is adjusted by this damping cloth 11.

With the above configuration, when a sound current is passed through the voice coil 3, the diaphragm 2 vibrates and becomes sound energy, and sound is output from the through hole 1a of the protector 1. Here, the frequency characteristics of the output sound vary depending on the breathability of the damping cloth 11. That is,
The presence of the damping cloth 11 restricts ventilation to the back side due to the vibration of the diaphragm 2, which affects the frequency characteristics. Figure 10 is a diagram showing an example of this frequency characteristic, and when the breathability is increased, the bass around the frequency _O is emphasized, compared to the damping cloth 11 which has a breathability that gives a relatively flat frequency characteristic _c1 . If the air permeability is reduced, _the frequency characteristic becomes c ₂ , which lacks bass around frequency _O.
In this way, by selecting the breathability of the damping cloth 11, the frequency characteristics are improved.

[Problem that the invention attempts to solve]

However, in the above-described configuration, the damping cloth 11 is indispensable in order to improve the frequency characteristics, and the work of attaching the damping cloth 11 must be carried out when assembling the headphone unit. First, the number of work steps and production costs increased.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention aims to solve the problems caused by using a damping cloth in a headphone unit.

[Means for solving problems]

The headphone speaker unit of the present invention includes a voice coil 3 to which a diaphragm 2 is attached, and a magnet 4 provided corresponding to the voice coil 3.
A headphone comprising a yoke 8 for fixing the magnet 4, and a terminal board 9 arranged on the back side of the yoke 8, in which the terminal board 9 has a plurality of through holes for adjusting the amount of ventilation. It is.

[Effect]

With the above-described configuration, the plurality of through holes 9a of the terminal board 9 adjust the amount of airflow from the diaphragm 2 to the back surface, and a headphone speaker unit with good frequency characteristics can be obtained even without a damping cloth. .

〔Example〕

Hereinafter, one embodiment of the headphone speaker unit of the present invention will be described with reference to FIGS. 1 to 4. Note that in FIGS. 1 to 4, parts corresponding to those in FIGS. 7 to 9 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 shows the internal structure of an external magnet type headphone unit, in which a diaphragm 2, a voice coil 3, a magnet 4, a plate 6, and a yoke 8 are arranged inside a protector 1. A terminal board 9 is attached to the back of the yoke 8. This terminal board 9 is a disk made of paper phenol, etc., and has a conductive pattern 9b formed along its periphery as shown in FIG. A large number of minute through holes 9a having a diameter of, for example, 0.5 mm for adjusting the amount of ventilation are provided, for example, 45 evenly distributed. The through hole 9a is formed at a position corresponding to the opening 8a of the yoke 8 when the terminal board 9 is attached to the back surface of the yoke 8. This terminal board 9 is attached to the back surface of the yoke 8, and a conductive wire from the outside is relayed through a conductive pattern 9b so as to be electrically conductive to the voice coil 3.

The through hole 9a of the terminal board 9 affects the frequency characteristics of the headphone. That is, the ventilation to the back of the headphone unit is restricted by the through hole 9c,
Frequency characteristics change. Here, the relationship between the size and number of the through holes 9a and the frequency characteristics of the headphone having the through holes 9a will be explained. FIG. 3 shows the frequency characteristics when the diameter of the through holes 9a is 0.5 mm, and the number of through holes 9a is selected so that the frequency characteristics have a value close to _a1 . For example, in the case of the unit of this embodiment, the number is 45. When the number of through holes 9a is reduced compared to this case, the frequency characteristic a ₂ will have insufficient ventilation and the bass around frequency ' _O will be insufficient, and when the number of through holes 9a is increased, The frequency characteristic of a ₃ is too breathable, so the bass around frequency ′ _O is emphasized, and neither sound is natural. In addition, Fig. 4 shows the diameter of the through hole 9a.
This shows the frequency characteristics when the diameter is 1.5mm.
In this case, even if the frequency characteristic b ₁ of the number of through holes 9a is the most flat, there is a valley between the bass frequency '_O' and the treble frequency _H , resulting in a drop in the midrange.
Furthermore, when the number of through holes 9a is increased compared to the case of the frequency characteristic b ₁ with a diameter of 1.5 mm, the frequency characteristic b ₃ is obtained in which the bass frequency ' _O area is emphasized and the treble frequency area _H area is insufficient. On the other hand, if you reduce the number, the bass frequency near _{the O} note will be insufficient, and the treble frequency near _H will be emphasized, resulting in a frequency characteristic b ₂ , which will result in a flat and natural sound in both cases. It is far from the frequency characteristics. As can be seen from these frequency characteristics, the through hole 9a is small, for example, in diameter.
If you leave a relatively large number of holes (0.5 mm), the air resistance against ventilation from the diaphragm 2 to the back will be applied evenly,
It has almost the same air permeability as the conventional arrangement of damping cloth, and has good frequency characteristics. In addition, the diameter of the through hole 9a is actually 0.7 mm.
It is preferable that it is below.

With the configuration described above, when a sound current is passed through the voice coil 3, the diaphragm 2 vibrates and sound is output. At this time, the ventilation to the back of the headphone unit due to the vibration of the diaphragm 2 is controlled by the yoke 8.
The air is discharged to the outside through the opening 8a of the terminal board 9 and the through hole 9a for adjusting the ventilation amount of the terminal board 9, but as mentioned above, the amount of ventilation to the back side is regulated by the minute through hole 9a. By appropriately setting the size and number of the through holes 9a as described above, it is possible to obtain a headphone having appropriate frequency characteristics even though there is no damping cloth.

Next, another embodiment of the headphone speaker unit of the present invention will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, this headphone unit is of an internal magnet type, in which a magnet 4' is arranged on the inner circumferential side of the voice coil 3. The yoke 8' that holds the magnet 4' has a step between the inner circumferential side and the outer circumferential side of the voice coil 3, and has openings 8a' and 8b' on the inner circumferential side and the outer circumferential side, respectively. The ventilation from the diaphragm 2 is transmitted through the opening 8a' on the side through the center portion of the magnet 4', and the ventilation from the diaphragm 2 is directly transmitted through the opening 8b' on the outer peripheral side. Then, a terminal board 9' is attached to the back surface of the stepped portion on the inner circumferential side of the yoke 8', and wiring is made to each conductive member using this terminal board 9'. FIG. 6 is a diagram showing the terminal board 9', in which a conductive pattern 9b' is formed on the periphery, and a small through hole 9a' is formed at a position corresponding to the central opening 8a' of the yoke 8'. There are multiple spaces. A brake cloth 11' is attached to an opening 8b' on the outer peripheral side of the yoke 8'.

With the above configuration, air from the diaphragm 2 to the back side is discharged through the opening 8a' on the inner peripheral side of the yoke 8' and the through hole 9a' of the terminal board 9'. There are two types of discharge: one is discharged through the opening 8b' on the outer peripheral side of the yoke 8' and the brake cloth 11. Here, the ventilation passing through the opening 8a' on the inner peripheral side of the yoke 8' has air resistance due to the through hole 9a' of the terminal board 9', and good frequency characteristics can be obtained even without the damping cloth. Note that the relationship between the number and size of the through holes 9a' and the frequency characteristics is the same as that shown in FIGS. 3 and 4, and it is better to make them small and provide a relatively large number of them. By doing this, the damping cloth only needs to be attached to the opening 8b' on the outer circumferential side of the yoke 8', and the opening 8a' on the inner circumferential side has the through hole 9a' of the terminal board 9'. There is no need to attach a brake cloth to the brake cloth or to stuff micron glass or the like into the center of the magnet 4' in place of the brake cloth.

Note that the present invention is not limited to the above-described embodiments, and various other configurations may be adopted without departing from the gist of the present invention.

[Effect of idea]

As described above, according to the present invention, a plurality of through holes are made in the terminal board for adjusting the amount of ventilation, and the ventilation from the diaphragm to the back side passes through these holes, thereby eliminating the need for a damping cloth. Therefore, even if the number of parts is reduced, the cost is reduced, and the assembly work efficiency is improved because there is no need to attach the brake change.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the headphone speaker unit of the present invention, Fig. 2 is a plan view showing an example of the terminal board used in the example shown in Fig. 1, and Figs. A line diagram for explaining the invention, FIG. 5 is a sectional view showing another embodiment of the invention, FIG. 6 is a plan view showing an example of a terminal board used in the example shown in FIG.
7 is a front view showing an example of a headphone, FIG. 8 is a sectional view showing an example of a conventional headphone speaker unit, FIG. 9 is a plan view showing a conventional terminal board, and FIG. 10 is a front view of a conventional headphone speaker unit. FIG. 3 is a diagram showing frequency characteristics. 2 is a diaphragm, 3 is a voice coil, 4 is a magnet, 8 is a yoke, 9 is a terminal board, and 9a is a through hole.

Claims (1)

[Scope of utility model registration request] A headphone speaker unit comprising a voice coil to which a diaphragm is attached, a magnet provided corresponding to the voice coil, a yoke for fixing the magnet, and a terminal board disposed on the back of the yoke. A speaker unit for headphones, characterized in that the terminal board is provided with a plurality of through holes for adjusting the amount of ventilation, and the plurality of through holes perform acoustic damping.