Sound Reproduction System and Device

The wonderfulness of live music comes from the facts that in addition to the fundamental notes of musical instruments several high harmonics reach the ears of humans appreciating the music and that the so-called undertones of less than 150 Hz directly vibrate the human body.

Various improvements and contrivances have been made to bring the recorded or taped music closer to live music, and a considerably high fidelity of sound reproduction has been attained. Nevertheless there is left room to be desired in direct transmission of vibration to the human body.

In this connection attention is drawn to the U.S. Pat. Nos. 3,384,710 and 3,416,804 which disclose devices with speakers buried in the cushions of chair backs and to the U.S. Pat. No. 3,452,836 which discloses a device with a speaker attached to the side of a chair shaped like a shell which encloses a sitting human.

An object of the present invention, which relates to a sound reproduction device, is to provide a reproduced music with an abundant effect of presence by driving the reproducing system and at the same time applying a pleasant vibration synchronized with the reproduced sound to the human seat by means of a transducer.

For the purpose of transmitting the vibration from the transducer to the human seat, the vibrating shaft of the transducer is directly fitted to the framework of the human seat. Such a connection to the framework better vibrates the part of the body of a sitting human contacting the seat than a transducer buried in a cushion.

The fixed position of the transducer relative to the framework is important. The most desirable position is to be near the caudal bone of a human listening to music. The reason is that, when a fleshy part of the human body is vibrated by the transducer, the vibration is mitigated by the flesh but when the vibration occurs near the caudal bone, the vibration is well transmitted from the caudal to the other bones.

In this invention a transducer in the prior art may be employed, and the framework may be composed of a main frame constituting the chair and a sub-frame, or it may be a single shell framework fabricated of synthetic resin, such as for example, FRP.

Other objects of the present invention will become apparent from the description of embodiments referring to the attached drawings.

FIG. 1 is a partially cutaway side view of one embodiment of the present invention.

FIG. 2 is a partial longitudinal sectional detail view of the transducer and its connection to the chair frame.

FIG. 3 is a detail side view of those principal parts in another embodiment of the present invention.

FIG. 4 is a rear perspective view showing a transducer attached to a chair main frame in another embodiment of the present invention.

FIG. 5 is a rear perspective view showing a transducer attached to a metal plate fitted to the chair main frame in a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a transducer attached to a sub-frame of a chair in a fifth embodiment of the present invention.

FIG. 7 is a partial detail of the sub-frame made of perforated board.

FIG. 8a is a perspective view showing the subframe attached with springs to the main frame in a sixth embodiment of the present invention.

FIG. 8b is an enlarged sectional detail view along line II -- II of FIG. 8a.

FIG. 9 is a rear perspective view of a seventh embodiment of the present invention.

FIG. 10a is a longitudinal sectional view corresponding to FIG. 9.

FIG. 10b is an enlarged detail of the transducer and part of the chair of FIG. 10a.

FIG. 11 is a perspective view of the framework of the chair of FIG. 9 as covered with a cloth of coarse texture.

FIG. 12 is an oblique view of the framework of a bed with a transducer attached according to the present invention.

FIG. 1, 1 is a side elevation of a chair or a sofa. Sofa 1 consists of framework 2 and cushioning 3. Framework 2 consists of the outline frame or main frame 2a, legs 2b and sub-frame 2c of metal screen, etc., attached to main frame 2a near the seat. In the present specification main frame 2a refers to a skeleton constituting a chair, sofa or bed, etc., and sub-frame 2c refers to the other part.

To sub-frame 2c is attached vibrating shaft 6 of transducer 5, such that practically the whole weight of the transducer is borne by said vibrating shaft. Transducer 5, as described later, is connected through lead 7 to the output side of a sound amplifier.

Referring to FIG. 2, the detail of transducer 5 is described. Transducer 5 is composed of yoke 8 fabricated of a magnetic material, drive coil 9, installed withdrawably at the center of yoke 8, vibrating shaft 6 integrated with drive coil 9, and first and second annular dampers 10 and 11, holding said vibrating shaft 6 against yoke 8.

Yoke 8 as illustrated has a T-cap section to which peripherally is attached annular permanent magnet 12. Drive coil 9 is composed of coil frame 13, shaped like a downward-open cup, and coil 14. A sound signal flows via the lead 7 (FIG. 1) through coil 14.

First damper 10 and second damper 11 are elastic metal discs having central holes 10a and 11a which receive and hold coil frame 13 and vibrating shaft 6. Posts 15 and 16 link yoke 8 and first and second dampers 10 and 11. Nuts 17 are tightening nuts.

The top end of vibrating shaft 6 is formed as a flange 18. Sub-frame 2c is fastened between flange 18 and tightening nut 19, and the whole transducer 5 is suspended from sub-frame 2c.

In sofa 1 thus constituted, when there is passed through coil 14 a current of less than, say 150 Hz., i.e., the frequency which can effectively cause vibration of sub-frame 2c, as a sound output from the amplifier 23 (FIG. 1), drive coil 9 vibrates in relation to yoke 8 through magnetic interference. The vibration thus produced is transmitted via vibrating shaft 6 to subframe 2c, thereby giving a pleasant vibration to a human sitting on sofa 1. That vibration is synchronized with the sound from speaker 24 located in front of sofa 1 and has a synergistic effect. Moreover, a circuit of a headphone or earphone 24' may be selectively connected to the output of the amplifier 23. In this connection, a speaker discribed in the claims includes the speaker 24, headphone and earphone 24' as shown in FIG. 1.

Since yoke 8 is suspended from vibrating shaft 6 and drive coil 9 by means of first and second dampers 10 and 11, naturally yoke 8 vibrates, but this vibration is a relative one causing vibration of drive coil 9, which vibration is then transmitted to sub-frame 2c.

In another embodiment of the present invention illustrated in FIG. 3, vibrating shaft 6 of transducer 5 comes above sub-frame 2c. In the following description the same or similar parts as in the above embodiment are denoted by the same symbols.

As stated in the above embodiment, the most remarkable effect of the present invention is attained when transducer 5 is impressed with a part of the amplified sound output in the reproduced music, whereby music can be appreciated through the ears and the whole body. When applied to a bed for action in sleep, the present invention induces satisfactory sleeping.

Transducer 5 may be variously positioned as described in the following:

FIG. 4 illustrates transducer 5 as directly attached to main frame 2a. In this example, the main frame 2a and legs 2b are metal pipes; an appropriate subframe, not shown, to support the human body is attached to main frame 2a. The seat and back of the framework are padded with cushioning or covered with cloth. In the case of transducer 5 being directly attached to main frame 2a, the vibration applied to the chair is transmitted to the floor. Therefore, it is necessary to provide an appropriate anti-vibration rubber pad between legs 2b and the floor.

FIG. 5 illustrates transducer 5, attached at its vibrating shaft to metal vibrator plate 2d welded to metal pipe main frame 2a.

In FIG. 6, just as in FIG. 1, sub-frame 2c is welded or riveted to main frame 2a, and transducer 5 is attached to sub-frame 2c. The only difference is that ribbed sub-frame 2c is constituted of a single plate. Of course the top and periphery of sub-frame 2c are padded with cushioning. The ribbed sub-frame refers to one in which the members run in both lateral and vertical directions. Sub-frame 2c may be a single perforated steel plate with a number of holes 4 punched therein, as shown in FIG. 7.

If sub-frame 2c is composed of a leaf spring or a perforated plate, and transducer 5 is attached thereto, the vibration from the transducer will be soft and will be not likely to transmit overtones, thereby giving a pleasant vibration to the sitting human. To achieve that result it is possible as illustrated in FIG. 5 to fix metal vibrator plate 2d to sub-frame 2c and to attach transducer 5 to metal plate 2d.

In some embodiments sub-frame 2c is directly welded or screwed to main frame 2a. As illustrated in FIGS. 8a and 8b springs 20 may be inserted to control or reduce transmission of vibrations from sub-frame 2c to main frame 2a. Springs 20 are connected to main frame extensions 2a' and to edges of sub-frame 2c.

In other embodiments illustrated in FIGS. 9, 10a, 10b and 11, ribbed framework 2 consisting of a seat and back is covered peripherally and overall with cloth 21 of course texture (FIG. 11) and further with a foamed synthetic resin layer 22, such as foamed urethane resin.

If framework 2 as covered with cloth 21 of coarse texture is placed in a mold and a foamed synthetic resin is poured therein, the synthetic resin in contact with said coarse texture cloth will not so vigorously foam, resulting in the more dense or lesser foamed layer 22' as shown in FIG. 10b. When transducer 5 fixed to framework 2 is caused to vibrate, the synthetic resin layer as a whole will be vibrated, whereby the more foamed top portion will absorb the overtones and the sitting human will be able to sense only the undertones as a pleasant vibration.

In this connection, it may be understood that foamed synthetic resin layers can be formed around the frames illustrated in FIGS. 4, 5, 6 and 8.

In the example illustrated in FIG. 12 transducer 5 is attached to sub-frame 2c of the bed framework, and the cushioning is omitted. Transducer 5 is desirably positioned at the sleeper's waist.

In the present invention beds, sofas or preferably chairs or like devices for holding humans are referred to as furniture.

As shown in FIG. 1 and as used in all embodiments, transducer 5 is connected to input means which are leads 7, which are in turn connected to an acoustic device 20' with a speaker 21'.

While the invention has been described with reference to a specific embodiment, modification and variations may be made without departing from the scope of the invention. The scope of the invention is defined in the following claims.