KR100221987B1 - Loud speaker device and television receiver using the device - Google Patents

Abstract

The speaker device of the present invention has a speaker 3 and an opening end and a closing end opposite thereto, and is connected to the sound wave emitting part of the speaker 3 to introduce sound waves emitted from the speaker 3 into the opening end. A sound tube 4 which is attached to the side wall of the sound tube 4, the sound tube 4 having a waveguide direction intersecting the direction of sound wave radiation from the speaker 3; The speaker 3 is attached to the sound tube 4 at an intermediate position between the closed end and the open end.

This configuration effectively suppresses standing waves occurring inside the acoustic tube 4, thereby enabling to realize satisfactory acoustic characteristics over a wide range from low to high frequencies.

Description

Speaker device and television receiver using same

1 is a fragmentary perspective view showing a television receiver according to the present invention.

2 is a perspective view showing a speaker device of the present invention.

3 is a cross-sectional view of the speaker device.

4 is an exploded perspective view of the speaker device.

5 is an exploded perspective view of a speaker device including a reflector.

6 is a fragmentary perspective view of the speaker device.

7 is a sectional perspective view of a speaker device in which terminals are provided at different positions.

8 is a cross-sectional view of the speaker device.

9 is a perspective view of an experimental speaker device.

10 is a cross-sectional view of the speaker device.

11 is a diagram showing various resonant modes.

FIG. 12 is a graph showing the sound pressure frequency characteristics obtained when the closed end of the sound tube is driven. FIG.

FIG. 13 is a diagram showing two experimental speaker devices with different attachment positions of speakers. FIG.

Fig. 14 is a graph showing the sound pressure frequency characteristics in the speaker device in which the speaker is provided at a distance of 1/2 from the closed end.

Fig. 15 is a graph showing the sound pressure frequency characteristics in the speaker device in which the speaker is provided at a distance 1/3 of the closed end.

FIG. 16 is a diagram showing an experimental speaker device filled with sound absorbing material. FIG.

17 is a graph showing the sound pressure frequency characteristics of the speaker device.

18 is a diagram showing an experimental speaker device having ridges on opposite sides of the speaker.

19 is a diagram showing sound pressure frequency characteristics of the speaker device.

FIG. 20 is a diagram showing an experimental speaker device having a reflector.

21 is a graph showing the sound pressure frequency characteristics of the speaker device.

22 is a balance diagram showing a speaker device arranged on a conventional television receiver.

23 is a plan view showing another conventional example.

* Explanation of symbols for main parts of the drawings

1: cabinet 2: speaker unit

3: speaker 4: sound tube

5: sound absorbing material 6: ridge

7: reflector 30: frame

31: diaphragm 32: terminal

43: front waveguide 44: rear waveguide

The present invention relates to a speaker device comprising a speaker and an acoustic tube attached thereto, and a television receiver having such a speaker device.

In FIG. 22, the television receiver comprises a CRT 11 housed in a cabinet 1 and a pair of opposing speakers 12 arranged around the CRT 11 in a dead space inside the cabinet 1.

Sound waves radiated by each speaker 12 are introduced into the front of the cabinet 1 by an acoustic tube 13 connected to the speaker 12.

In recent years, as the size of a television receiver increases, the speaker 12 also uses a larger aperture.

Attempting to arrange such a large-diameter speaker 12 on opposite sides of the CRT 11 as shown in FIG. 22 makes it impossible to fully store the speaker 12 in the dead space inside the cabinet 1, eg For example, it is necessary to inflate the side walls of the cabinet 1.

This raises the problem of increasing the lateral width of the cabinet 1.

Thus, as shown in FIG. 23, a method of connecting the sound tube 14 to each of the laterally facing speakers 12 in a state slightly inclined with respect to the front surface of the cabinet 1 can be considered.

In this way, the large-diameter speaker 12 can be arranged in the dead space inside the cabinet 1 in a dense state.

However, the speaker device of FIG. 23 has a problem that the acoustic characteristics of the midrange are impaired especially because the sound waves radiated by the speaker 12 are refracted at a large angle close to 90 ° and introduced into the sound tube 14.

In both speakers shown in FIGS. 22 and 23, sound waves emitted from the speaker 12 are radiated forward from the open end of the sound tube after they are introduced into the sound tubes 13 and 14. At this time, a part of the sound wave is reflected due to the significant change in the acoustic impedance at the opening of the sound tube and is returned to the speaker 12 to generate a standing wave.

For example, when three quarters of the standing wave wavelength is equal to the length of the acoustic tube (three quarter wave standing wave), resonance occurs and a significant peak occurs in the sound pressure frequency characteristics at around 700 Hz 1 kHz. Damaged.

In order to eliminate the interference of sound pressure frequency characteristics caused by standing waves, a speaker device is proposed in which a sound tube is provided with a sound absorbing material surrounding a sound wave radiating portion of a speaker to absorb standing waves. 5-168082]. However, the device cannot absorb standing waves effectively because the sound waves reflected to the front of the speaker do not collide with the sound absorbing material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speaker device configured to realize a satisfactory acoustic characteristic in a wide range from low to high frequencies by guiding the waveguide direction of the sound tube inclined with respect to the radiation direction of sound waves from the speaker and effectively absorbing standing waves. .

According to the present invention, there is provided a speaker device comprising a speaker 3 and an acoustic tube 4 having an opening end and a closed end opposite to the opening end and connected to an acoustic wave radiating part of the speaker.

The speaker 3 is attached to the side wall of the sound tube 4, and the sound tube 4 has a waveguide direction intersecting the sound wave radiation direction from the speaker 3. The speaker 3 is attached to the sound tube 4 at an intermediate position between the closed end and the open end.

The standing wave generated inside the sound tube 4 has a fracture at the closed end of the sound tube 4 and has a break at the open end, and one or more breaks occur between the closed end and the open end to resonate. Therefore, in the conventional apparatus in which the speaker is attached to the extended end of the acoustic tube, the attachment position is opposite to the fracture position of the standing wave, so that the loudspeaker driving force is largely involved in the generation of the standing wave, thereby generating a large standing wave.

On the other hand, in the speaker device of the present invention, the speaker 3 is attached to the sound tube 4 at an intermediate position between the closed end and the open end, and the attachment position is also opposite to one of the standing positions of the standing wave.

This reduces the speaker drive efficiency with respect to the standing wave, suppressing the standing wave, and in particular, improving the acoustic characteristics of the midrange.

In particular, the speaker 3 is attached to the sound tube 4 at a position spaced from the closed end toward the open end by a distance corresponding to about 1/3 of the total length of the sound tube 4. The standing position of the standing wave is spaced from the closed end toward the open end by a distance corresponding to, for example, about one third of the total length of the acoustic tube 4. In a particular configuration in which the speaker 3 is attached at this position, the attachment position of the speaker 3 is opposite the break position of the 3/4 wavelength standing wave, thereby effectively preventing resonance of the 3/4 wavelength standing wave.

In a particular configuration, the sound tube 4 is filled with the sound absorbing material 5 in an inner portion closer to the closed end than the attaching position of the speaker 3. In this particular configuration, all the reflected waves reflected from the open end of the acoustic tube 4 are absorbed by the sound absorbing material when they collide with the sound absorbing material 5.

Further, in the above configuration, the waveguide of the sound pipe 4 has a substantially constant cross-sectional area or has an increased cross-sectional area from the attachment position of the speaker 3 toward the open end. In addition, the waveguide of the acoustic tube 4 has a cross-sectional area that decreases from the attachment position of the speaker 3 toward the closed end. In this particular configuration, the cross-sectional area size of the acoustic tube opening end at which the reflected wave occurs is different from the cross-sectional area of the acoustic tube closing end at which the half wave finally reaches, which asymmetrically attenuates the reflected wave at the closed end.

The sound tube 4 expands toward the speaker 3 and has a truncated cone-shaped ridge 6 on its side opposite the sound wave radiator. The speaker diaphragm has a reduced shape, which significantly changes the cross-sectional area of the waveguide at the outlet of the speaker 3, and the change in this cross-sectional area is canceled by the ridges 6 of the specific configuration. This reduces the change in acoustic impedance at the connection between the speaker 3 and the sound tube 4.

In another particular configuration, the acoustic tube 4 is equipped with a reflector 7 in its interior at a particular position closer to the closed end than the attachment position of the speaker 3 to partially block the waveguide at that particular position.

This particular configuration can effectively provide improved acoustic features at high frequencies and enable the realization of well-balanced acoustic properties from mid to high frequencies.

In addition, the terminals 32 and 32 for energizing through the speaker 3 are supported on the frame 30 at a position spaced from the center of the speaker 3 toward the open end of the acoustic tube 4, and the litz wire ( The litz wires 33 and 33 extend from the terminals 32 and 32 toward the diaphragm 31.

In this particular configuration, an unbalance of sound pressure resistance with respect to the diaphragm 31 of the speaker 3, that is, a larger sound pressure resistance unbalance at the closed end side than at the open end side, extends from the terminal 32 to the diaphragm 31 and the lead wire. This is offset by the increase in the equivalent mass due to the weight of the Ritz wire 33 and the weight of solder for fixing the Ritz wire 33 to the lead wire. Therefore, the diaphragm 31 vibrates only primarily along the radial direction of the sound wave, thereby obtaining a high quality sound without distortion.

The present invention relates to a cathode ray tube 11 housed in a cabinet 1, a speaker 3 arranged on an opposite side surface of the furnace tube 11, and arranged laterally in an interior of the cabinet 1 and this speaker 3; Television comprising a pair of speaker devices 2, 2, each having a sound tube 4 connected to the sound wave radiating portion of the cabinet 1 and extending from the closed end inside the cabinet 1 to the open end in front of the cabinet 1; Prepare a water phase. The speaker 3 is attached to the side wall of the sound tube 4, and the sound tube 4 has a waveguide direction intersecting the sound wave radiation direction from the speaker 3.

The speaker 3 is attached to the sound tube 4 at an intermediate position between the closed end and the open end.

The television receiver using the present invention can be arranged inside the cabinet 1 so that the speakers can be densely arranged using dead space without requiring the cabinet 1 having a large lateral width even if the speaker 3 has a large aperture. Has a pair of speaker devices 2, 2 arranged laterally at a distance from the front thereof and arranged at opposite sides of the CRT 11. In addition, since the speaker 3 of each speaker device 2 is attached to the sound pipe 4 at an intermediate position between the closed end and the open end, the standing wave is effectively suppressed.

The inclination of the acoustic waveguide direction with respect to the sound wave radiation direction from the speaker has a problem of causing a peak inclination mainly in the vicinity of the midrange, which is effectively suppressed in the case of the speaker apparatus of the present invention and a television receiver using the apparatus. This results in satisfactory acoustic properties over a wide range, from low to high frequencies.

Some embodiments of the present invention will be described in detail with reference to the drawings.

1 shows a television receiver of the present invention in which the speaker device 2 of the present invention is incorporated.

The opposite paired speaker devices 2 are arranged on opposite sides of the CRT 11 inside the cabinet 1.

Each speaker device 2 uses a dead space inside the cabinet 1 so as to be spaced from the front of the cabinet 1 so as to be laterally oriented in the inside thereof, and inside the cabinet 1. A sound tube 4 having a closed end and an open end facing the front of the cabinet.

The front of the speaker 3 is attached to the side wall of the sound tube 4.

The speaker 3 is generally a cone-shaped dynamic speaker, as shown in FIG. 2, and has a diaphragm 31 supported by a damper on the frame 30 in the form of cone paper.

The diaphragm 31 is driven by energizing through a speaker via a pair of terminals 32 and 32.

In FIG. 3, the speaker 3 is attached to the sound tube 4 at a position spaced from the closed end to the open end by a distance corresponding to 1/3 of the total length of the sound tube 4.

The sound tube 4 comprises a combination of the first panel 41 and the second panel 42, which panels extend from the position of the speaker 3 toward the open end 43 and the speaker 3. To form a rear waveguide 44 extending toward the closed end.

As shown in FIG. 4, the width of the front waveguide 43 of the acoustic tube 4 increases toward the open end according to a predetermined function and the thickness decreases toward the open end in the inverse relationship of the function, thereby reducing the waveguide ( 43 maintains a constant cross-sectional area from the attachment position of the speaker 3 to the open end.

Thus, the open end of the sound tube 4 has a narrow rectangular opening extending vertically in front of the cabinet 1.

This minimizes the increase in the lateral width of the cabinet 1.

In contrast, the rear waveguide 44 of the acoustic tube 4 gradually decreases in cross-sectional area as it goes toward the closed end.

The rear portion of the waveguide 44 is filled with the sound absorbing material 5.

A circular opening 45 for introducing sound waves from the speaker 3 through the sound tube 4 into the first panel 41 is formed at the position where the speaker 3 is attached to the sound tube 4. have.

The second panel 42 has a truncated cone-shaped ridge 6 that conforms to the shape of the speaker diaphragm 31 and swells toward the speaker 3 on the opposite side of the circular opening 45 of the first panel 41.

5 and 6 show a speaker device having a pair of reflecting plates 7, 7 spaced apart from one another and arranged at the inlet of the rear waveguide 44 of the sound tube 4.

The waveguide 44 is also filled with the sound absorbing material 5 similarly to the rear portions of the reflecting plates 7 and 7.

7 and 8 show a speaker device in which the terminals 32, 32 of the speaker 3 are supported on the frame 30 at a position spaced apart from the center of the speaker 3 toward the open end of the acoustic tube 4; Shows.

The litz wires 33 and 33 extend from the terminals 32 and 32 toward the diaphragm 31.

The effect of the speaker device described above was experimentally confirmed using the experimental speaker device of the type shown in FIGS. 9 and 10.

11 and 12 show the results of the experiment.

As shown in FIGS. 9 and 10, the experimental speaker device has an experimental sound tube 8 having a constant cross-sectional area over the entire length of the waveguide and a speaker 3 attached to the side wall of the sound tube 8, It basically takes the same structure as the speaker device of the present invention.

The microphone 9 was provided on the opposite side of the open end of the acoustic tube 8 to determine the sound pressure frequency characteristics.

The total length of the experimental sound tube 8 was 350 mm and the cross-sectional area was 105 mm x 50 mm.

The microphone 9 is spaced apart from the open end of the sound tube 8 by 10 mm.

11 shows standing waves occurring in an acoustic tube having a constant cross-sectional area.

If the length of the acoustic tube is L, the frequency F at which standing waves occur is expressed by the following equation (1).

Formula (1): F = (c / 4L) x (2n + 1)

Where c is the speed of sound and n is an integer (0, 1, 2, ...).

Assuming L = 0.35 m and c = 340 m / s, frequencies F1, F2 and F3 at which standing waves of 1/4, 3/4 and 5/4 wavelengths occur are as follows.

F1 = 243 Hz

F2 = 729 Hz

F3 = 1214 Hz

In the case where the closed end of the sound tube is driven by a speaker having a frequency specification shown by the broken line in FIG. 12, the frequency characteristic of the sound wave emitted from the sound tube repeats a significant peak slope over the mid to high frequencies as shown by the solid line. To disturb the characteristics.

In addition, the solid line frequency characteristics were calculated by computer simulation.

On the other hand, the frequency characteristics shown in Figs. 15 and 14 show that the type A device and the speaker are closed at the position where the speaker is 1/3 of the total length of the sound tube from the closed end as shown in Fig. 13. It is obtained from the results of experiments performed on type B devices installed at a position half of the total length of the acoustic tube from the stage.

In particular, for type B where the speaker is at 1/2 position, the characteristic curve is slightly out of frequency band (1 kHz) than when the closed end is driven as shown in solid line in FIG. Shows a large slope at and a decrease in sound pressure around 1500 Hz.

On the other hand, in the case of type A where the speaker is 1/3, as shown by the solid line in FIG. 15, it is completely suppressed from the mid-range to the high-range so that no slope is seen around 300 Hz and a sufficiently high sound pressure level is obtained at 1000 to 1800 Hz. Thus, satisfactory sound pressure frequency characteristics can be obtained.

This effect is the result of a rupture of a standing wave with a third position at a wavelength of 3/4 (which occurs at a frequency of 729 Hz in this experiment).

In order to suppress standing waves, it may be considered to reduce the driving efficiency for generation of standing waves by driving the position of the crush.

In addition, the experimental results in FIG. 15 show that the peak in the mid range is significantly reduced near 729 Hz, demonstrating the effect of the speaker device of the present invention.

FIG. 16 shows a D-type experimental speaker device in which the rear portion of the sound tube is filled with a sound absorbing material.

Figure 17 shows the frequency characteristics measured in the device.

As shown by the solid line in FIG. 17, the peak slope is effectively suppressed from the mid range to the high range. This is caused by the sound waves returned by the reflection at the open end of the acoustic tube colliding with the sound absorbing material and absorbed by the sound absorbing material without leakage, thereby suppressing resonance of the standing wave.

FIG. 18 shows an E-type speaker device in which the acoustic tube corresponds to the shape of the diaphragm and has a ridge on the opposite side of the speaker.

19 shows the frequency characteristics measured in the device.

As shown by the solid line in FIG. 19, the apparatus exhibits a higher sound pressure than the D-type speaker apparatus (dashed line) over the range of 800 to 2500 Hz.

The reason for this is as follows.

In the position where the sound wave radiated from the speaker diaphragm of the D-type device is introduced into the acoustic tube, the waveguide has a sharply enlarged portion formed by the concave diaphragm, whereas in the E-type device, the cross-sectional area of the waveguide at the exit of the speaker is formed in the ridge. This is because an acoustic tube is made uniform by this and there is no sharp change in cross-sectional area, thereby ensuring uniformity of acoustic impedance when sound waves radiated from the speaker pass through the acoustic tube.

Fig. 20 shows an F-type speaker device having a pair of reflecting plates in the front of the sound absorbing material inside the sound tube.

Figure 21 shows the frequency characteristic measured in the device.

As shown in FIG. 21, the inclination in the range of 6000 to 7000 Hz is smaller than that of the E-type device (broken line). This shows that by providing a reflector the sound pressure is adjustable in the high range.

According to the invention, the speaker 3 corresponds to an intermediate portion with the sound tube 4, preferably about 1/5 to 3/5, more preferably 1/3 of the total length of the sound tube 4. It is attached to the sound tube 4 at a position spaced from the closed end by a distance, which can effectively reduce the peak slope occurring in the sound pressure frequency characteristics of the speaker device.

In addition, if the acoustic tube is filled with the sound absorbing material (%), forms the ridges 6, and includes the reflecting plate 7, improved frequency characteristics can be obtained from the mid range to the high range.

In addition, when the terminals 32 and 32 of the speaker 3 are moved from the closed end of the acoustic tube 4 to the open end, the dislocation of the resistance acting as a load when the diaphragm 31 vibrates can be eliminated, thereby distorting. You can get high sound quality without this.

Since the front waveguide 43 of the sound tube 4 has a constant cross-sectional area while extending in front of the sound tube, the sound tube has a constant acoustic characteristic from the attachment position of the speaker 3 to the open end and the front waveguide 43 In the middle of the reflection does not occur and functions as a so-called Helmholtz resonance tube.

In the television receiver using the present invention, the pair of opposing speaker devices 2 and 2 can be densely arranged inside the cabinet 1 by effectively utilizing the dead space formed on the opposing side surfaces of the CRT 11.

Therefore, the large-diameter speaker 3 can be used easily.

The embodiments described above are intended to illustrate the invention and are not intended to limit the invention as set forth in the appended claims.

In addition, the apparatus of the present invention is not limited to the configuration of the embodiment, and may be modified in various forms within the technical spirit of the present invention described in the claims.

For example, instead of having the front waveguide 43 of the sound tube 4 have a constant cross-sectional area toward the open end as in the above embodiment, the front waveguide 43 may be enlarged while moving toward the open end to obtain a horn effect. .

Although the apparatus of the present invention has been described with respect to the basic shape in which the speaker 3 is attached to the middle portion of the acoustic tube 4, the apparatus is filled with the sound absorbing material 5 and forms the ridge 6 and is in a changed position. It is also possible to take an additional configuration in which the reflector 7 and the terminals 32 and 32 are provided.

However, it is not necessary to provide all of these additional means to the device, and one or more of them may be optionally added.

Claims (10)

A sound tube 4 having a speaker 3 and a closed end opposite the opening end and connected to the sound wave radiating portion of the speaker 3 for introducing sound waves radiated from the speaker 3 into the opening end. The speaker 3 is attached to the side wall of the sound tube 4, the sound tube 4 has a waveguide direction that crosses the sound wave radiation direction from the speaker 3, the speaker 3 Is attached to the sound pipe (4) between the closed end and the open end corresponding to the break position of the standing wave occurring inside the sound pipe (4). The rear waveguide according to claim 1, wherein the waveguide of the sound tube (4) extends from the closed end to the open end, and extends toward the closed end and the speaker (3) is located on the closed end side of the center waveguide part opposite the sound wave radiator. A speaker device having a portion. The sound tube (4) according to claim 1, wherein the speaker (3) is attached to the sound tube (4) at a position spaced from the closed end toward the open end by a distance corresponding to 1/5 to 3/5 of the total length of the sound tube (4). Speaker device, characterized in that. 4. The sound pipe (4) according to claim 3, characterized in that the speaker (3) is attached to the sound pipe (4) at a position spaced from the closed end toward the open end by a distance corresponding to one third of the total length of the sound pipe (4). Speaker unit. 2. A speaker device according to claim 1, characterized in that the sound tube (4) is filled with a sound absorbing material (5) in the interior closer to the closed end than the attachment position of the speaker (3). 2. Speaker device according to claim 1, characterized in that the sound tube (4) has a waveguide having a constant cross-sectional area or a cross-sectional area which increases from the attachment position of the speaker (3) toward the open end. 2. Speaker device according to claim 1, characterized in that the acoustic tube (4) is provided with a waveguide having a reduced cross-sectional area going from the attachment position of the speaker (3) toward the closed end. 2. A speaker device according to claim 1, characterized in that the acoustic tube (4) has a truncated cone-shaped bulge (6) bulged out on the opposite side of the sound wave radiator toward the speaker (3) in its own undergarment. The method according to claim 1, characterized in that the acoustic tube (4) is provided with a reflector (7) therein at a particular position closer to the closed end than the attachment position of the speaker (3) to partially block the waveguide at the particular position. Speaker unit. The CRT 11 housed in the cabinet 1, the speaker 3 arranged on the opposite side of the CRT 11 and disposed laterally in the cabinet 1 and the sound waves of the speaker 3 A pair of speaker devices 2, 2, each having a sound tube 4 connected to the radiating part and extending from the closed end inside the cabinet 1 to the open end of the front of the cabinet 1; 3) is attached to the side wall of the sound pipe 4, the sound pipe 4 has a waveguide direction intersecting the sound wave radiation direction from the speaker 3, the speaker 3 of the sound pipe 4 A television receiver, characterized in that it is attached to an acoustic tube (4) between a closed end and an open end corresponding to a breaking position of standing waves occurring therein.