Earpiece and headset

Abstract

There is provided an earpiece or a headset comprising an audio input for receiving an audio signal to be reproduced, at least one electroacoustic reproduction transducer, an audio unit for effecting audio processing of the received audio signal, at least one converter unit for extracting power from the audio signal received at the audio input, a power storage means for at least partial intermediate storage of the power extracted from the audio signal, and a power control unit for controlling the extraction of the power from the audio signal and for controlling a power supply of the audio unit, in particular by way of the power stored in the power storage means and extracted from the audio signal.

Claims

1. An earpiece or a headset comprising an audio input configured to receive an audio signal to be reproduced; at least one electroacoustic reproduction transducer configured to reproduce the received audio signal; an audio unit configured to effect audio processing of the received audio signal; at least one converter unit configured to extract power from the audio signal received at the audio input; a power storage means configured to at least partially intermediately store the power extracted from the audio signal; and a power control unit configured to control the extraction of the power from the audio signal and to control a power supply of the audio unit; wherein the power control unit is adapted to limit a mode of operation of the earpiece or the headset by reducing a level of active noise cancellation to reduce a power consumption of the audio unit if there is no longer sufficient power in the power storage means.

2. The earpiece or headset as set forth in claim 1; wherein the power control unit monitors whether, after extraction of power from the received audio signal, there is sufficient power in the audio signal to be able to drive the electroacoustic reproduction transducer, operate the audio unit, or both.

3. An earpiece or headset comprising: an electroacoustic reproduction transducer; an audio unit configured to effect audio processing of an audio signal; a boom microphone; an input configured to receive a microphone feed supply for the boom microphone; at least one converter configured to extract power from the microphone feed signal; a power storage means configured to at least partially intermediately store the power extracted from the microphone feed signal; and a power control unit configured to control the extraction of power from the microphone feed signal and to control the power supply of the audio unit; wherein the power control unit is adapted to limit a mode of operation of the earpiece or the headset by reducing a level of active noise cancellation to reduce a power consumption of the audio unit if there is no longer sufficient power in the power storage means.

4. A method of controlling an earphone or a headset, wherein the earphone or the headset has an audio input, an audio unit, and an electroacoustic reproduction transducer, comprising the steps: receiving an audio signal which is to be reproduced by way of the audio input; effecting audio processing of the received audio signal; extracting power from the audio signal received at the audio input; effecting at least partial intermediate storage of the power extracted from the audio signal; controlling the extraction of power from the audio signal and controlling a power supply of the audio unit; and limiting a mode of operation of the earphone or the headset by reducing a level of active noise cancellation to reduce a power consumption of the audio unit if there is no longer sufficient power in the power storage means.

5. The earpiece or headset as set forth in claim 1; wherein at least one of the power extracted by the at least one converter unit and the power stored by the power storage means is used at least partially as supply power for operating at least the audio unit.

6. The earpiece or headset according to claim 5, further comprising: a rectifier adapted to rectify the audio signal received at the audio input to obtain a DC signal.

7. The earpiece or headset according to claim 6, further comprising: a DC/DC converter, wherein a DC signal fed into the DC/DC converter is provided by the rectifier or by the power storage means.

8. The earpiece or headset as set forth in claim 3; wherein at least one of the power extracted by the at least one converter unit and the power stored by the power storage means is used at least partially as supply power for operating at least the audio unit.

9. The earpiece or headset according to claim 8, further comprising: a rectifier adapted to rectify the audio signal received at the input to obtain a DC signal.

10. The earpiece or headset according to claim 9, further comprising: a DC/DC converter, wherein a DC signal fed into the DC/DC converter is provided by the rectifier or by the power storage means.

11. The method as set forth in claim 4, further comprising: wherein at least one of the extracted power and the stored power is used at least partially as supply power for operating at least the audio unit.

12. The method as set forth in claim 11, further comprising: a step of rectifying the received audio signal to obtain a DC signal.

13. The method as set forth in claim 12; wherein the earphone or headset further has a DC/DC converter, the method further comprising a step of DC/DC converting a DC signal provided by the rectifier or by the power storage means.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic block circuit diagram of a headphone or a headset according to a first embodiment; and

(2) FIG. 2 shows a schematic block circuit diagram of a headphone or a headset according to a second embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

(3) It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, many other elements which are conventional in this art. Those of ordinary skill in the art will recognize that other elements are desirable for implementing the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein.

(4) The present invention will now be described in detail on the basis of exemplary embodiments.

(5) FIG. 1 shows a schematic block circuit diagram of a headphone or a headset according to a first embodiment. The earpiece or the headset has an audio input 110 for receiving an audio signal to be reproduced, a rectifier unit 120 for rectifying the audio signal received by way of the audio input 110, a DC/DC converter unit 130, an audio unit 140, at least one electroacoustic reproduction transducer 150, an power control unit 160, an power storage unit 170 and an electronic unit 180. The audio signal can be output by an external audio source 200 (for example a media player, a smartphone etc).

(6) The audio signal which is to be reproduced and which is produced or output by the external audio source 200 represents an audio signal substantially without direct component DC. That audio signal can optionally have no bias but can represent a normal audio signal to be reproduced.

(7) The rectifier 120 converts the audio signal at the audio input 110 from the external audio source 200 into a DC signal. The output signal of the rectifier 120 can be converted to a higher or lower level by the DC/DC converter 130. The audio unit 140 can effect audio signal processing, for example active noise cancellation, and the corresponding signal can be output by way of the electroacoustic reproduction transducer 150. As the input signal the power control unit 160 has the voltage value of the audio signal and/or the current value of the audio signal and optionally the voltage value of the power storage means 170. The power control unit 160 can output as its output signal a control signal to the unit 180 or to the audio unit 140 and can control the functioning of the electronic unit 180 or the audio unit 140.

(8) According to the first embodiment power is extracted from the input audio signal by means of the rectifier unit 150 and/or the DC/DC converter 130 and the extracted power can be put into intermediate storage in the power storage unit 170 or used for the power supply to the audio unit 140, the power control unit 160 and/or the electronic unit 180. If it should not be possible to extract sufficient power from the input audio signal then components of the electronic unit 180 and/or the audio unit 140 can be at least temporarily deactivated. For that purpose the power control unit 160 can be coupled to the audio unit 140 to be able to establish whether the audio unit 140 is receiving sufficient power from the audio signal to be able to suitably reproduce the audio signal on the electroacoustic reproduction transducer 150, to be able to effect active noise cancellation or to be able to effect other audio signal processing.

(9) According to the invention the DC/DC converter 130 can use the power from the power storage unit 170 to supply an electronic system of the earpiece with a suitable voltage.

(10) According to the invention the DC/DC converter 130 is so controlled that the input resistance R.sub.L is kept substantially constant. Power adaptation can be achieved by means of a variation in the input resistance for example by voltage maximization. It is possible in that way to provide for improved adaptation to the audio source.

(11) The DC/DC converter 130 also serves to feed the power storage unit 170. According to the invention the power which can be used for the system is proportional to the voltage U.sub.Q1, wherein the voltage is controlled at the power storage unit by the power control unit.

(12) Thus the efficiency of the earpiece or the headset can be improved in comparison with the state of the art which uses a linear regulator or a linear amplifier.

(13) By virtue of the fact that a part of the power required for the earpiece or the headset is not extracted from a power storage means in the earpiece/headset, for example in the form of a battery or an accumulator, but is extracted from the input audio signal the power storage means (the battery/accumulator) can be dispensed with or at least the service life thereof is considerably increased.

(14) FIG. 2 shows a schematic block circuit diagram of an earpiece or a headset according to a second embodiment. The earpiece or the headset 100 has a first DC/DC converter 121 connected to an external voltage supply 300 by way of a connection 111, wherein the external voltage supply represents a microphone feed voltage or a feed voltage of a mobile device. The first DC/DC converter 121 converts the input voltage into an output voltage which can be higher or lower than the input voltage. A second DC/DC converter 130 is coupled to the first DC/DC converter 121. The second DC/DC converter 130 serves to supply the audio unit 140 which for example can have an active noise cancellation unit or another audio processing unit with a suitable (for example constant) output voltage. The first DC/DC converter 121 can serve to feed the storage unit 170. The storage unit 170 can be for example in the form of a capacitor, for example an ultra-cap. The earpiece or the headset according to the second embodiment further has a first microphone 191 and a second microphone 192. The first microphone 191 serves as a microphone for active noise cancellation and the second microphone 192 can be in the form of a boom microphone supplied with a microphone feed voltage by way of the input 111. The earpiece or the headset further has a power control unit 160 which provides for voltage monitoring of the storage unit 170. The power control unit 160 can optionally also be adapted to limit the operation of the audio unit or the electronic unit 180 if there is not sufficient power in the storage unit 170. For example the level of active noise cancellation can be reduced to reduce the power consumption. If however the storage unit 170 has for example a very great deal of power then that power can be used for example for the electronic unit 180.

(15) The first DC/DC converter 121 has for the target parameter a variable microphone voltage as a reference in order thus to achieve a voltage-dependent load resistance together with the first DC/DC converter. According to the second embodiment a maximum possible amount of power can be extracted from the microphone feed for the boom microphone 192 by the first converter unit 121. The power which can be used for the earpiece or the headset is proportional to the voltage at the storage unit 170.

(16) The advantages of the earpiece or the headset according to the second embodiment correspond to the advantages of the earpiece or the headset of the first embodiment.

(17) Depending on the audio source involved a differing amount of energy can be extracted from the audio signal. An aviation microphone connection provides for example a voltage of between 8 and 16 V with an output resistance of 470 ohms, that is to say the connection can provide at least 60 mW. An analog audio stereo signal with a 32 ohm load can provide 1 Vrms, that is to say a power of 62.5 mW. A microphone connection on a cellular phone or a mobile device can provide for example 3.3 V with an output resistance of 1 kohm, that is to say the mobile device can provide 5 mW. An analog audio stereo signal with a load of 8 ohms can provide a voltage of 150 mVrms and a power of 5.6 mW.

(18) Optionally an ultra-cap can be used as the power storage means.

(19) According to the invention between 0 and 100% of the power from the audio signal can be at least partly fed to the power storage means.

(20) While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the inventions as defined in the following claims.