A interference-free transmitting receiving earset includes a housing houses a speaker, a grille covering the speaker and having a front center tube, and two microphones mounted in the center tube of the grille in reversed directions to pick up sound waves from the user's external auditory canal and wound waves from the speaker respectively and to eliminate interference of sound waves from the speaker with sound waves produced by the user in the external auditory canal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a transmitting receiving earset and more particularly, to an interference-free transmitting receiving earset

2. Description of the Related Art

FIG. 13shows a conventional transmitting receiving earset5for use with a cellular telephone B. According to this design, the transmitting receiving earset5comprises a speaker51and a microphone52. According to this design, the microphone52is kept at a distance away from the speaker51. During communication, the microphone52picks up the user's voice and the surrounding noises, lowering the communication quality.

FIG. 14shows an earset for wireless communication according to the prior art. According to this design, the earset6comprises an elongated housing61, a speaker62installed in one end of the housing61, a microphone63installed in the other end of the housing61, and an ear hook64connected to the housing61for securing the housing61to the user's ear. This design of earset6cannot eliminate interference of external noises.

U.S. Pat. No. 5,909,498 discloses a transducer device, which includes a pair of transducers in the form of a speaker element and a microphone element mounted in a common housing. According to this design, the speaker element is directed to face the external auditory canal, and the microphone element is positioned in the housing with the receiving side directed toward the outside of the housing. Further, a plate is interposed between the speaker element and the microphone element for isolation to avoid feedback, i.e., audio coupling. Structurally, the housing houses the speaker element and the microphone element. Actually, the microphone element is adapted to receive voices directly from the user's mouth. Sound waves pass from the user's mouth through the air and the rear side of the housing to the microphone element for further transmission to communication apparatus. The microphone element is not kept inside the user's external auditory canal and blocked therein after insertion of the transducer device into the user's ear. Therefore, this design of transducer device cannot eliminate the microphone element from receiving external noises produced by surrounding workplaces, factories, and motor vehicles. During communication through the transducer device, surrounding noises are simultaneously received by the microphone element and transmitted with the user's voice to the remote communication apparatus, thereby causing the person at the remote side cannot hear the voice of the user of the transducer device clearly. Further, because the microphone element is positioned in the rear side of the housing with the receiving side of the microphone element hidden inside the housing, the voice receiving effect of the microphone element is lowered, thereby affecting the communication quality. U.S. Pat. No. 5,909,498 also discloses one alternate form in which the housing has two separated chambers for accommodating the microphone element and the speaker element, a sound passage, and separating means that separates the sound passage into two parallel sound passages for the speaker element and the microphone element respectively. According to this design, the speaker element and the microphone element are positioned in the house in a close manner. Sound waves from the speaker element will be transmitted through the housing to the microphone element, thereby causing the microphone to pick up noises and to transmit the noises to the communication apparatus at the remote side. Further, because the output port of the sound passage for microphone and the output port of the sound passage for speaker are arranged close to each other. Sound waves that pass out of the output port of the sound passage for speaker will partially pass into the output port of the sound passage for microphone and then guided by the sound passage for microphone to the microphone, causing the microphone to transmit the feedback sound waves. Thus, the voice of the person at the remote side will be transmitted to the microphone again, and the microphone will transmit the feedback noises and the voice of the user of the transducer device to the person at the remote side. At this time, the person at the remote side will hear the feedback sound. The interference of the feedback noises greatly affects the communication quality.

U.S. Pat. No. 5,363,444 and U.S. Pat. No. 5,844,984 show another two different designs. According to these two designs, the microphone is positioned on the outside of the housing for picking up the user's voice. During communication, the microphone picks up the user's voice as well as surrounding noises from surrounding workplaces, factories and motor vehicles. Because the user's voice and surrounding noises are transmitted to the remote side, the person at the remote side may be unable to hear the voice of the person at the proximity side. Further, because the microphone is provided at the outside of the housing, it is not kept close to the user's mouth. Therefore, the transmitting quality is poor.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an interference-free transmitting receiving earset, which is insertable into the user's ear at a deep distance to hold the speaker inside the external auditory canal for picking up sound waves produced by the user accurately, improving the communication quality. It is another object of the present invention to provide an interference-free transmitting receiving earset, which blocks the user's external auditory canal after insertion of the earset into the user's year, preventing interference of external noises. It is still another object of the present invention to provide an interference-free transmitting receiving earset, which eliminates interference of external sound waves and noises with the sound waves produced by the user in the external auditory canal, improving the communication quality. It is still another object of the present invention to provide an interference-free transmitting receiving earset, which enables the user to hear the voice from the speaker, preventing interference of the voice from the speaker with the microphone that receives sound waves produced by the user in the external auditory canal. It is still another object of the present invention to provide an interference-free transmitting receiving earset, which is inexpensive to manufacture. To achieve these and other objects of the present invention, the interference-free transmitting receiving earset comprises a housing; a speaker mounted in the housing; a front grille fastened to the housing and covered over the speaker, the front grille having a center tube and a plurality of through holes spaced around the center tube; a first microphone mounted inside the center tube of the front grille, the first microphone having a receiving side facing the speaker for picking up sound waves from the speaker; and a second microphone mounted inside the center tube of the front grille reversed to the first microphone, the second microphone having a receiving side facing the outside of the center tube for receiving sound waves from the user's external auditory canal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

transmitting receiving earset in accordance with a first embodiment of the present invention is shown comprising a housing1, a speaker11mounted in the housing1, a grille12, which is fastened to the housing I and covered over the speaker11and, which has a center tube122and a plurality of through holes121spaced around the center tube122, a set of microphones13,14mounted in the axial center through hole1221of the center tube122of the grille12, and an ear cushion15covered on the grille12around the center tube122. The microphones13,14have the respective electric wires131,141arranged together. When installed, the receiving side132of one microphone13faces the speaker11, and the receiving side142of the other microphone14facing the outside of the center tube122opposite to the speaker11. When the user inserted the earset into the external auditory canal21of the ear2, the microphones13,14are held inside the external auditory canal21. During communication, the microphone14picks up resonant sound waves from the external auditory canal21and transmits picked up voice signal to the external communication apparatus, for example, a cellular telephone Δ. At the same time, the microphone13picks up sound waves from the speaker11to prevent interference of sound waves with the resonant sound waves produced by the user in the external auditory canal21. Therefore, the microphone14is free from the interference of the speaker11. Further, because the speaker11is installed in the front side inside the housing1, the microphones13,14are kept inside the external auditory canal21of the ear2, and the ear cushion15blocks the external auditory canal21, preventing interference of external noise with the microphones13,14.

FIG. 4shows a second of the present invention. According to this embodiment, the speaker11is installed in the housing1in a backward position reversed to the position shown inFIG. 2; the housing1is made having a back opening (or grille)16facing the speaker11for the passing of sound waves.

FIG. 5shows a third embodiment of the present invention. According to this embodiment, a silicon rubber plug124is fixedly fastened to the periphery of the center tube122of the grille12for insertion with the earset into the user's external auditory canal. The silicon rubber plug124has a skirt portion125, which attenuates sound waves produced by the speaker11, preventing interference of the wound waves with the microphone14.

FIGS. 7 and 8show a fourth of the present invention. According to this embodiment, speaker11of the earset is fastened to a hollow shell10, which houses a wireless transmitter receiver circuit3and a battery31. The battery31provides the necessary working voltage to the wireless transmitter receiver circuit3. The wireless transmitter receiver circuit3is electrically connected to the speaker11and the microphones13,14. Further, the hollow shell10is provided with a hook32for fastening the assembly to the user's ear.

FIGS. 9 and 10show a fifth embodiment of the present invention. According to this embodiment, the interference-free transmitting receiving earset comprises a housing1, a speaker11mounted in the housing1, a grille12, which is fastened to the housing1and covered over the speaker11and, which has a center tube122and a plurality of through holes121spaced around the center tube122for the passing of sound waves from the speaker11, a microphone14mounted in the axial center through hole1221of the center tube122of the grille12, and a conical silicon rubber plug17fastened to the center tube122of the grille12. The center tube122has a locating groove123extended around the periphery. The conical silicon rubber plug17has a rear retaining flange171fastened to the locating groove123of the center tube122of the grille12. The conical silicon rubber plug17attenuates sound waves produced by the speaker11, eliminating interference of the sound waves with the microphone14.

FIG. 11shows sixth embodiment of the present invention. According to this embodiment, the interference-free transmitting receiving earset comprises a housing1, a speaker11mounted in the housing1, a grille12, which is fastened to the housing1and covered over the speaker11and, which has a center tube122and a plurality of through holes121spaced around the center tube122, a microphone14fastened to the inside of the axial center through hole1221of the center tube122of the grille12and partially extended out of the center tube122, and a conical silicon rubber plug18fastened to the microphone14outside the center tube122of the grille12. The conical silicon rubber plug18has a center mounting hole182extended through the front and rear sides and fastened to the periphery of the microphone14, and a skirt-like peripheral wall181. After insertion of the earset into the user's external auditory canal, the conical silicon rubber plug18attenuates sound waves produced by the speaker11, eliminating interference of the sound waves with the microphone14. Further, the center tube122may be made having a plurality of radial through holes to substitute for the through holes121for the passing of sound waves from the speaker11.

FIG. 12shows a seventh embodiment of the present invention. According to this embodiment, the interference-free transmitting receiving earset comprises a housing1, a speaker11mounted in the housing1, a flexible grille4, which is fastened to the housing1and covered over the speaker11and, which has a front extension43, a plurality of through holes41spaced around the front extension43, and a hollow cylindrical receptacle42at the free end of the front extension43, a microphone14fastened to the inside of the center hole421of the hollow cylindrical receptacle42, and a conical silicon rubber plug18fastened to the periphery of the hollow cylindrical receptacle42. The conical silicon rubber plug18has a center mounting hole182extended through the front and rear sides and fastened to the periphery of the hollow cylindrical receptacle42, a skirt-like peripheral wall181, and a plurality of radial through holes41extended through the skirt-like peripheral wall181. After insertion of the earset into the user's external auditory canal21, the conical silicon rubber plug18attenuates sound waves produced by the speaker11, eliminating interference of the sound waves with the microphone14.

A prototype of interference-free transmitting receiving earset has been constructed with the features ofFIGS. 1˜12. The interference-free transmitting receiving earset functions smoothly to provide all the features discussed earlier.