JP2000287291A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax reduction in a sound pressure caused at a high sound frequency band in a speaker system where a speaker is connected to a side face of an acoustic tube. SOLUTION: In the speaker system, a sound wave radiation section of a speaker 4 is connected to a side face of an acoustic tube 5 whose one end is open and whose other end is closed in a way that a waveguide direction of the acoustic tube 5 is in crossing with a sound wave radiation direction of the sound wave radiation section so as to lead the sound wave emitted from the speaker 4 to the open end of the acoustic tube 5. In this case, a protrusion 6 is formed on a face of the acoustic tube 5 opposite to the speaker 4, and a slope tilted in the direction toward the open end of the acoustic tube 5 is provided in a part of the protrusion 6 opposite to the middle of the speaker 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker device in which a sound tube is connected to a loudspeaker, and more particularly to a loudspeaker device in which a sound guide direction of a sound tube is inclined with respect to a sound wave radiation direction of the speaker. .

[0002]

2. Description of the Related Art In a television receiver, a cathode ray tube (2) is accommodated in a cabinet (1) as shown in FIG. 8, and a dead space generated between the cabinet (1) and the cathode ray tube (2) is utilized. Then, a pair of left and right speaker devices (3) in which the speakers (4) are connected to the acoustic tubes (5) are arranged, and the sound waves radiated from each speaker (4) are transmitted to the acoustic tubes (4) connected to the speakers (4). 5) leads to the front of the cabinet (1).

On the other hand, with the recent increase in the size of television receivers, there is a demand for a large-diameter speaker (4) capable of obtaining higher sound quality. Therefore, in order to prevent the cabinet (1) from being further increased in size due to the increase in the diameter of the speaker (4), the speaker (4) is connected to the cabinet (1) as shown in FIG.
A method of arranging it obliquely horizontally with respect to the front surface of the sound tube and connecting it to the acoustic tube (5) has been considered.

Although such a method is effective for suppressing the width of the cabinet, it cannot be said that the sound quality is such a structure that good sound quality can be obtained. That is, in the structure shown in FIG. 9, sound waves emitted from the speaker (4) and guided in the acoustic tube (5) toward the front of the cabinet (1) are transmitted through the opening of the acoustic tube (5). Abrupt changes in acoustic impedance at the edges will cause some to be reflected. The sound wave reflected at the open end returns inside the acoustic tube (5), and is further reflected at the opposite closed end, thereby becoming a standing wave having a wavelength depending on the entire length of the acoustic tube (5). Such a standing wave causes a sharp peak and dip in the sound pressure frequency characteristics, and causes deterioration of the acoustic characteristics. Further, the deterioration of the acoustic characteristics due to the rapid change of the acoustic impedance also occurs at the speaker exit due to the concave shape of the speaker diaphragm.

As a method for preventing the deterioration of acoustic characteristics due to such a sudden change in acoustic impedance, for example, Japanese Patent Laid-Open Publication No. Hei 8-331885 has been proposed. That is, as shown in FIGS. 10 and 11, by disposing the speaker (4) at a position from the closed end to the open end by about 側 of the total length of the acoustic tube (5), In addition to suppressing the resonance due to the 3/4 wavelength standing wave that particularly adversely affects the acoustic characteristics, the acoustic tube (5) has a truncated conical shape protruding toward the speaker (4) on the side facing the speaker (4). Ridge (6)
Is provided to alleviate a sudden change in acoustic impedance at the exit of the speaker (4).

[0006]

However, in the prior art shown in FIGS. 10 and 11, there is a problem that the sound pressure drops to the opening end of the sound tube in the high frequency band. This is because, in a cone type speaker, the position where the sound in the high frequency band is generated is at the center of the speaker diaphragm, while the sound in the high frequency band has a strong directivity and has a characteristic that it is difficult to spread. The high sound wave radiated from the central part of the speaker (4) is reflected at the top of the opposing raised part (6) and returns, which is thought to be due to less reflection and diffusion toward the opening end of the acoustic tube (5). Can be

[0007]

In order to solve the above-mentioned problems, a speaker device according to the present invention is provided with a sound radiating portion of a speaker (4) on a side surface of an acoustic tube (5) having one end opened and the other end closed. In a speaker device which is connected such that the waveguide direction of the acoustic tube (5) intersects the sound wave emission direction and guides the sound wave radiated from the speaker (4) to the open end of the acoustic tube (5),
A raised portion (6) is formed on the surface of the acoustic tube (5) facing the speaker (4), and the raised portion (6) has a portion of the acoustic tube (5) opposed to the center of the speaker (4). An inclined surface inclined toward the opening end is provided.

[0008]

1 to 4 show an embodiment of a speaker device according to the present invention, which will be described below with reference to the drawings.

In this embodiment, as shown in FIG.
Starting from the open end of (5), there is an acoustic tube (5) front part perpendicular to the front surface of the cabinet (1) and a sound tube (5) rear part bent along the cathode ray tube (2). ing. In such a structure, the rear portion of the cabinet (1) can be formed in a narrowed shape, so that the design is easy to arrange at the corner of the room, and the rear portion of the speaker (4) faces the cabinet (1). The interference of the sound leaking from the rear of the speaker (4) can be suppressed, and the separation of the sound from the left and right speakers (4) can be improved.

1 to 4, (4) is a cone-shaped speaker, (5) is an acoustic tube, and the acoustic tube (5) has a bent shape as shown in FIG. (4) is disposed at a position extending from the closed end to the open end by about 約 of the total length of the acoustic tube (5).

(6) is an acoustic tube (5) facing the speaker (4).
A frusto-conical raised portion provided in the inside is a concave groove formed with an inclined surface inclined toward the opening end of the acoustic tube (5), and is a center of the speaker (4), that is, the speaker (4). Are provided partially on the raised portion (6) facing the high-frequency sound radiation area. Also,
The concave groove (7) extends to the bent portion of the acoustic tube (5).

Reference numeral (8) denotes a phase matching device formed in the acoustic tube (5). The phase matching device is a sound wave emitted from the speaker (4) and directed toward the opening end of the acoustic tube (5). It is provided so as to reduce the path difference at the end and to match the phase at the opening end.

According to this embodiment, the speaker (4)
The ultrasonic wave emitted from the central portion of the acoustic tube is reflected by the apex of the raised portion (6) and does not return to the speaker (4) itself, but by the inclined surface of the concave groove (7) formed opposite to the acoustic tube ( It is guided toward the opening end of (5), and is effectively taken out without being attenuated in the acoustic tube (5).

FIG. 6 shows the result of measuring the sound pressure frequency characteristics in an anechoic room by mounting the speaker device of this embodiment in a wooden box. FIG. 7 shows the result of similarly measuring the sound pressure frequency characteristics according to the conventional example shown in FIG. As is clear from the figure, the conventional example has a treble frequency band of 5,000 to 5,000.
It can be seen that the drop in sound pressure that appeared around 10,000 Hz was alleviated in the present embodiment, and good sound pressure frequency characteristics were obtained.

In the above embodiment, the acoustic tube (5) is of a bent type, but as shown in FIG.
Even in the case of a non-bending type, it is possible to reduce a decrease in the sound pressure of a treble sound by forming an inclined surface similar to that of the present embodiment in the raised portion (6).

The inclined surface is not limited to being formed by the concave groove (7), but may be formed by further providing a convex portion on the raised portion (6), or by forming a combination of the concave groove and the convex portion. Needless to say, it is good.

[0017]

As described above, according to the loudspeaker apparatus of the present invention, the loudspeaker is provided by providing an inclined surface at the portion of the raised portion facing the loudspeaker which faces the center of the loudspeaker. Since the high-frequency sound waves emitted from the loudspeaker are guided toward the open end of the acoustic tube, a decrease in sound pressure in a high-frequency band is mitigated, and a good loudspeaker device having a flat sound pressure frequency characteristic can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a speaker device according to the present invention.

FIG. 2 is a partial perspective view showing one embodiment of the present invention.

FIG. 3 is a partial perspective view showing an acoustic tube according to one embodiment of the present invention.

FIG. 4 is a sectional view showing one embodiment of the present invention.

FIG. 5 is a sectional view showing a state where one embodiment of the present invention is attached to a television receiver.

FIG. 6 is a characteristic diagram showing a sound pressure frequency characteristic of one embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a sound pressure frequency characteristic of a third conventional example.

FIG. 8 is a sectional view showing a state in which the first conventional example is attached to a television receiver.

FIG. 9 is a sectional view showing a state in which the second conventional example is attached to a television receiver.

FIG. 10 is a cross-sectional view showing a state in which the third conventional example is mounted on a television receiver.

FIG. 11 is a sectional view of a third conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cabinet 2 cathode ray tube 3 speaker device 4 speaker 5 acoustic tube 6 raised portion 7 concave groove 8 phase matching device

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hideki Hatazoe 1-1, Sanyocho, Daito-shi, Osaka Sanyo Electronics Parts Co., Ltd. F-term (reference) 5D017 AE24 5D018 AD18 AE13

Claims (3)

[Claims] An acoustic tube (5) having one end open and the other end closed.
The sound radiating portion of the speaker (4) is connected to the side surface of the speaker (4) such that the wave guide direction of the acoustic tube (5) intersects the sound wave emitting direction, and the sound wave radiated from the speaker (4) is transmitted to the acoustic tube (5). In the speaker device leading to the opening end of the speaker (4), a raised portion (6) is formed on the surface of the acoustic tube (5) facing the speaker (4), and the raised portion (6) is located at the center of the speaker (4). A speaker device characterized in that an inclined surface that is inclined in the direction of the opening end of the acoustic tube (5) is provided at a portion facing the speaker device. 2. The speaker device according to claim 1, wherein the inclined surface is formed by providing a groove in a raised portion. 3. The speaker device according to claim 1, wherein the acoustic tube is bent in a direction opposite to a connection side of the speaker along the waveguide direction.