CN1337140A

CN1337140A - Headphone

Info

Publication number: CN1337140A
Application number: CN 00802834
Authority: CN
Inventors: 亨利·阿齐马; 马丁·科洛姆斯; 丹尼斯·莫里克罗夫特
Original assignee: New Transducers Ltd
Current assignee: NVF Tech Ltd
Priority date: 1999-02-05
Filing date: 2000-02-07
Publication date: 2002-02-20
Also published as: TW468357B; GB9902442D0; WO2000046786A3; EP1147680A2; WO2000046786A2; JP2002536899A; AU2446200A

Abstract

The headphones (1) comprising a headband (2) with ear speakers (3) each comprising a sound source in the form of a stiff lightweight panel (5) and a vibration exciter (6) for launching bending waves into the panel to produce an acoustic output.

Description

Earphone

What the present invention relates to is earphone, especially comprises the earphone of bending wave panel-form loudspeakers, and this bending wave panel-form loudspeakers for example is the distribution pattern acoustic radiator of the general type of International Patent Application WO 97/09842 explanation.

It is the piston acoustic source that is concerned with basically that conventional earphone adopts.These earphones have significant near-field effect, and transducer is extremely important in the placement of syrinx import.And be difficult to predict and control that the actual frequency that ear is heard responds.The plane earphone design of known belt and electrostatic is heavy and expensive.

Comprise according to earphone provided by the present invention: the sound source of a resonant panel form; And transducer apparatus, in plate, launch bending wave, and produce output.This sound source can be a distribution pattern acoustic radiator.Earphone preferably includes a pair of distribution pattern acoustic radiator.

A pair of or each distribution pattern acoustic radiator can comprise the plate of a hard and light weight, and wherein, honeycomb core is sandwiched between opposed covering.

It is electric inertia device form that bending wave is emitted to transducer apparatus in the plate.

Earphone so that distribution pattern sound plate is made except that having low potentiality of cost and light and handy structure, also provides the more radiating pattern of diffusion, thereby has reduced the standing wave effect to head in bigger radiation areas, also reduced the near field problem simultaneously.The orientation of head is far away inessential for the good sound quality.

In order to implement the present invention, adopted a thin plate, this newspaper thin plate is designed so that distribution pattern can work well in wide frequency ranges.Thin plate is installed on that an elasticity is outstanding holds, and together helps setting up one with the minimum beam mode of determining and is generally 30Hz to 20kHz near field audiorange.This is to utilize the small-sized electric transducer of a low coil inductance to realize.

In order to reduce cost, or even disposable application, can make distribution pattern sound plate with the reinforcement of card base, and drive with the low-cost PZT (piezoelectric transducer) of suitable mechanical couplings.The analog structure material can be used for the earphone headring so that its weight is the lightest.

In the accompanying drawing below, by way of example the present invention has been carried out graphic extension.In the accompanying drawings:

Fig. 1 is the Headphone device perspective view;

Fig. 2 is the partial cross section figure of Headphone device shown in Figure 1;

Fig. 3 is the Headphone device sectional view similar to Fig. 2 of another example;

Fig. 4 is the Headphone device sectional view similar to Fig. 2 of another example;

Fig. 5 is the Headphone device sectional view similar to Fig. 2 of another example;

Fig. 6 is the Headphone device sectional view similar to Fig. 2 of another example;

Fig. 7 is the plane graph of another example of Headphone device;

Fig. 8 is the possible position figure of vibration exciter on the bending wave plate; And

Fig. 9 is the frequency response curve of a preferred earpiece.

As shown in Figures 1 and 2, a Headphone device (hereinafter to be referred as " earphone ") 1 comprises the cushion member 2 of a reverse U shape shape, and this member forms an earphone headring, and substantially by conventional arrangement, head-mounted loud speaker 3 is supported in earphone headring leg free end.Lead 4 also is to be connected to an acoustic amplifier (not shown) output by conventional arrangement substantially.According to the present invention, each head-mounted loud speaker comprises a resonant acoustic radiator, and this radiator has the lamina membranacea 5 and a vibration exciter 6 of a hard lightweight.Vibration exciter 6 is fixed in this lamina membranacea, launches bending wave in plate, makes this plate resonance and the output of generation sound.International Patent Application WO 97/09842 has illustrated preferred distribution pattern resonance bending wave acoustic radiator.

In this embodiment, example as shown in Figure 1, this can be freely to support resonant panel to each of earphone, its physical parameter is chosen to make a mode frequency and a small-sized exciter that is fit to interlock, this small-sized exciter is positioned at a predetermined eccentric position and drives this plate, to be coupled with mode profile satisfactorily.

With the earphone headring headset assembly is worn on the head.Also used a cable, audio signal has been supplied with the exciter of each sound channel, two sound channels have generally been arranged, stereo to produce.In order to produce optimum efficiency, the size of plate is generally 50mm * 70mm or 50mm * 56mm, but also can make plate bigger or littler according to design limit such as price, size, quality and frequency ranges.Plate roughly is centrally located on the ear.

As seen from Figure 2, plate 5 holds 8 and is supported in the shell of a plastic moulding or covers among 7 by an elastic perimeter is outstanding, and has constituted a cavity 9, wherein is filled with acoustic damping material 10.This shell is formed with a protuberance or extension 11 to hold exciter 6.Preferably, plate 5 can with saturating sound lid or grid hide.For improving user's comfortableness, can be at the circumferential arrangement cushion 12 of plate 5.Shown in shell or to cover 7 are back side closures, but also can be backside openings.

The example of one head-mounted loud speaker 3 has been shown among Fig. 3, wherein cover shown in Fig. 1 and Fig. 2 example or shell 7 are substituted by open framework 14, plate 5 is supported on elastic perimeter is outstanding holds on 8, the both sides of plate 5 all use the lid of sound or grid 13 to hide, and cover or grid 13 is supported on this framework 14.In the configuration of earphone 1 shown in Figure 4, each head-mounted loud speaker 3 comprises a cover or a shell 17, is used for supporting a resonant panel 5 and exciter 6.Shell 17 is substantially similar to shell shown in Figure 2, but its inboard 15 extends internally, round plate 5 and constituted a delivery outlet 16 that can align user's syrinx.Therefore, shell extension 15 forms a passage 18 with plate 5 medial surfaces, and by this passage, the acoustic energy of whole plate is sent to delivery outlet.About this point, the output that should remember the bending wave plate is incoherent, and is different with the relevant output of piston type head-mounted loud speaker, therefore, avoided relevant sound is delivered to the problem of syrinx.

Earphone shown in Figure 5 comprises a head-mounted loud speaker 3, and this loud speaker has a cover 27, and this cover has a framework 14, plate 5 is supported on an elasticity is outstanding holds on 8.Exciter is installed on this plate, bending wave is input into this plate and the output of generation sound, with foregoing closely similar.But in this example, cover 27 forms a passage 18 with the outer surface of plate 5, the delivery outlet 19 of an end of this passage for communicating with atmosphere.The effect of this passage is the sound of the whole outer surface of plate 5 to be exported reload on this plate, and like this, the inner surface of this plate 5 to the sound output of user's ear can be strengthened certainly.

In earphone example shown in Figure 6, this head-mounted loud speaker 3 has a sizable cover 37, and this cover will seal by 12 couples of users' of a cushion ear, and forms closed-system.

In earphone shown in Figure 7, paired head-mounted loud speaker 3, for example aforesaid type is installed in the end of earphone headring 2 by supporting member 20, and the attitude of these supporting member 20 relative these earphone headrings is adjustable.This to head-mounted loud speaker 3 in, each head-mounted loud speaker 3 is installed on the hinge member 21, and this hinge member is installed on the member 20, like this, this headphone can be adjusted position and attitude according to user's ear, makes tonequality the best of uppick.Simultaneously, this head-mounted loud speaker can slide along this supporting member 20, to change the attitude of this head-mounted loud speaker.For this purpose, this member 21 can slide on member 20.

Fig. 8 shows the possible installation site of exciter 6 at plate 5, basically as WO 97/09842 instructs.Shown in the A being the most effective near the center, but instructing as WO 99/37121 near marginal position shown in the C shows the good tonequality of feeling.

Studies show that two kinds of local audition methods of known driving ear are pressure-driven and speed drive, the advantage of this speed method is the sensation nature and reduces ear's fatigue, the feature that promptly long-term earphone is listened to.Open to the outside world (open air) earphone that generally uses in the commerce as the earphone that German Sennheiser makes, is sought help from speed designs, compares with the traditional type earphone of need secure seal, does not need by pressure secure seal ear.Can obtain combining of pressure and speed sound energy to a bending wave plate in import department of ear near centre-driven.When purpose is when obtaining higher tonequality, efficient is just so unimportant, because more budget is used for booster output and magnetism intensity, in any situation, earphone power demand size is than the big or small low several magnitude of loud speaker power demand, therefore, if feel that the sound size of loud speaker needs 1 watts, so, earphone only needs 10mW.A feature of the present invention is for the staggered resonant panel of pattern, makes pressure composition minimum, and speed composition maximum.Exciter is used for the edge or near marginal position, and the selection of this position is in order to have good Mode Coupling, but this is that the selection of position or balance help average rather than absolute efficiency.Like this, during excitation plate, mainly be that bending wave traverses plate, almost there is not or do not have plane (ripple) component.Therefore bending wave, provides the required speed drive of equivalence smoothly by syrinx for the sound field of ear.

Because the pattern resonance that on the whole zone of plate, has complexity, near random, sound field is diffusion naturally widely, so, the acoustical coupling of plate and ear can be avoided common cavity and peripheral resonance effect greatly, and this effect is that the placement because of the traditional coherent piston type speaker element that uses in the earphone causes.One displacement causes.Compare with traditional technology, the standing wave mode that coherent source drives can not be in novel earphone and the regional development between ear.

Though on whole or part periphery, can realize the compact in size of plate and installation/boundary condition easily with outstanding the holding of compliance foam of polymers,, also can use multiple other panel material and structure.Use single-piece and composite plate structure to obtain good effect, and because therefore boundary condition can use metals such as the thick aluminium alloy of 0.15mm to 0.8mm, signal bronze or zinc for quite little plate operation.Remove various polymer, outside poly charcoal acid ester, polystyrene and the person like that, the bonding single-piece of carbon fibre resin also can be used, and thickness is reduced to 0.1mm from 0.8mm.When efficient is less demanding,, can use various exciters from 9mm to 19mm polar diameter according to required bandwidth and loudness.

When exciter is installed in the C position, the local quality damping of plate can be provided, instruct as WO99/37121.Experimental results show that the weak effect of position, angle B.

Fig. 9 is the frequency response curve of preferred exemplary earphone.Wherein, plate is made of aluminium flake, and exciter is contained in position C shown in Figure 8, and has the quality damping, as WO 99/37121 instructs.

The invention provides a kind of Novel earphone, the shortcoming that this earphone has avoided the piston device to bring does not have the expensive shortcoming of electrostatic earphone yet.

Claims

1. earphone comprises the sound source and an exciter of the plate form of a hard and light weight, and exciter is emitted to bending wave in the plate, produces an output.

2. earphone according to claim 1 comprises a pair of opposed head-mounted loud speaker.

3. earphone according to claim 1 and 2, wherein this plate hard and light weight is an aluminium sheet.

4. according to the described earphone of aforementioned arbitrary claim, wherein this exciter is a kind of exciter of electric inertia device form.

5. according to each described earphone in the claim 2 to 4, wherein this head-mounted loud speaker comprises a cover that constitutes acoustic conducting pipe.

6. earphone according to claim 5, wherein this acoustic conducting pipe has a delivery outlet that aligns with user's syrinx.

7. according to claim 5 or 6 described earphones, wherein this acoustic conducting pipe is loaded into this plate to the acoustic energy that is derived from this plate.

8. according to each described earphone in the claim 2 to 7, comprise an earphone headring, wherein this head-mounted loud speaker is installed on this earphone headring, and its attitude is adjustable with respect to user ear.

9. earphone according to claim 1, wherein, hard and plate light weight is the sort of distribution pattern acoustic radiator of being instructed among WO97/09842 or the WO99/37121.