EP4117305B1 - Mobile portable conversation microphone - Google Patents

Description

The invention relates to a mobile portable conversation microphone for simultaneously recording several speakers in different channels, comprising a housing, a microphone array provided in a front of the housing for recording the audio signals of the speakers, a processor connected to the microphone array and a battery for supplying power to the processor, wherein the housing has a front leg, a rear leg and a connecting section, and wherein a slot is formed between the front leg and the rear leg and the connecting section connects the front and rear legs.

State of the art

It is common practice to provide portable dictation microphones or conversation microphones with a clip on the back so that they can be attached to a piece of clothing or similar.

From the state of the art ( US 2004/0042630 A1 ), for example, a portable conversation microphone is known which has a housing with a rear leg which is used to attach the device to a piece of clothing, for example. The rear leg is designed as a simple clip which, in contrast to the weight of the device, is set back. The center of gravity of the device is therefore far in the front leg of the housing, which contains all the electronics and also the battery. However, such devices have the disadvantage that the center of gravity is far towards the front of the device, which means that the device cannot be adequately attached to clothing, for example in a breast pocket. The device always tends to tip forwards, or to shift with every movement and hang outwards at an undefined angle. On the one hand, this is uncomfortable for the wearer, and on the other hand, the constant shifting or incorrect alignment leads to distortions in the recording of the audio signals, or in particular to problems when separating the signals of several speakers into different channels. Conversational microphones with microphone arrays for recording and separating audio signals from multiple speakers are particularly dependent on the distance between speaker and microphone remaining approximately constant and not changing quickly. If the distance varies greatly and quickly, for example by tilting the device back and forth on clothing, complex recalculations are constantly required, which in mobile devices leads to a significant reduction in battery performance and negatively affects the quality of channel separation.

Other mobile portable conversation microphones are available in EN 20 2015 101145 U1 , US 2018/249245 A1 , US 2020/296521 A1 , US 2015/055798 A1 and US 2019/051377 A1 revealed.

Disclosure of the invention

The present invention therefore has the object of improving a mobile, portable conversation microphone of the type mentioned at the outset in such a way that it enables more reliable channel separation of several speakers and a longer service life.

The invention solves the problem by a mobile, portable conversation microphone according to claim 1. Preferred embodiments of the invention are defined in the dependent claims.

If the housing of the portable conversation microphone according to the invention has a front and a rear leg and the battery is at least partially arranged in the rear leg, the center of gravity of the conversation microphone can be shifted towards the rear leg, since the battery is sometimes the heaviest component of the conversation microphone. By shifting the center of gravity towards the rear leg, it can be achieved that when the conversation microphone with its slot between the front and rear legs is placed over a piece of clothing, such as a breast pocket, the latter tilts towards the body and always rests firmly against it. In contrast to the prior art, the conversation microphone according to the invention thus achieves a stable position on the body, enabling reliable channel separation while requiring low computing power.

In the sense of the invention, a microphone array is understood to be an arrangement of several microphones that can be used to determine the position of sources in sound fields. The microphones are preferably logically linked via a processor. MEMS microphones or the like can be used as microphones.

Conversation microphones with a microphone array are usually used to simultaneously record the audio signals of several speakers and to separate them into independent channels. Ideally, a channel corresponds exclusively to the audio signal of one speaker. Channel separation can be achieved using beamforming. Beamforming is a measurement principle in which audio signals are recorded using the microphone array and the time shift between the correlating audio signals recorded in the respective microphones is calculated. The time shift corresponds to the travel time from the speaker to the respective microphone and can be converted into a distance taking the speed of sound into account. By adding up the time-correlated signals from all microphones in the array, a time signal associated with the respective measuring point, whereby audio signals from other positions are attenuated due to the lack of correlation, or destructively superimpose. Temporally correlated signals from the same position, however, are amplified or constructively superimposed. In this way, a channel associated with each speaker can be formed from the audio signals of several speakers recorded by the microphone array, which essentially only contains the audio signals of the respective speaker.

Only a reliable beamforming technology enables a downstream calculation of the two channels with a EP2 930 917B1 known algorithm to significantly improve channel separation, even when both speakers are speaking at the same time, either already in the device or in a cloud server.

The conversation microphone according to the invention can improve the channel separation and the signal-to-noise ratio (SNR) of the individual channels due to the particularly stable position and the associated largely constant positioning of the microphones

According to one embodiment of the invention, the first leg can at least partially form the front of the housing and the second leg can at least partially form the back of the housing. This makes it possible to create a housing for the conversation microphone in a technically and structurally simple manner that can achieve the above advantages. The (partial) formation of the back of the housing also means that the housing does not have any further elevations or elements on the back that would prevent it from being placed flat and stable on a table. In contrast to the prior art, this means that there is no need for a clip that protrudes from the back, which would prevent it from being placed stable on a flat surface.

In addition, in a further embodiment, the microphone array can be provided at least partially in the front leg, which at least partially forms the front of the housing. This can have the particularly advantageous result that the front leg can be adapted precisely to the requirements of the microphone array in its internal and external design. For example, the front leg can be optimized for the microphone array in terms of its resonances and damping properties without taking the other components into account.

According to a further embodiment, the front leg can be thinner than the rear leg. Preferably, the rear leg is thicker than the front leg by a factor of 2.

In order to create a particularly stable and robust conversation microphone, the connecting section is inventively made in one piece with the front and rear legs. The connecting section preferably extends between the front and the rear of the housing, i.e. over its entire thickness.

According to a further embodiment variant, the connecting section can preferably form an upper section of the housing and the front and rear legs together form a lower section of the housing.

In order to reliably attach the conversation microphone to a piece of clothing or the like, a retaining spring can be provided in the slot between the front and rear legs according to a further embodiment.

According to yet another design variant, the slot can extend from the bottom of the housing across the middle of the housing. This allows the conversation microphone to be pushed far over a piece of clothing, for example, and thus be attached to it even more securely due to the lower center of gravity, which in turn is beneficial to the quality of the channel separation.

For convenient operation of the conversation microphone, according to one design variant, operating elements and/or display elements can be provided in the connection section on one or more front sides and/or on the top of the housing. This allows the person to wear the conversation microphone on the body and operate it at the same time, for example with the index finger and thumb, while its slot is placed over a piece of clothing, for example a breast pocket.

In a preferred embodiment, a display can be provided on the top of the housing, which is connected to the processor for displaying information. In addition, the processor can be designed to determine the current speaker using the beamforming algorithm and display it on the display. In another embodiment, the current user can be shown on the display, which means that the device works in the system with their user profile. The WiFi transmission of the data requires the device to be registered in the system and linked to the user profile. The display can also show other information, e.g. the name of the patient that the user (doctor) is currently dealing with.

The stable position of the conversation microphone on the body can be achieved particularly reliably if the center of gravity of the housing is behind a center plane of the slot in the direction of the back of the housing. The center plane runs essentially parallel to the inside of the slot on the front and rear legs. In a preferred embodiment, the center plane can also run essentially parallel to the front and back of the housing.

Because the microphone array according to the invention has at least four microphones spaced apart from each other, beamforming can be optimized for different frequency bands.

According to a further embodiment, the microphone array can additionally have at least two microphones spaced apart from one another on the top, which are also connected to the processor. The upward-facing microphones can in particular significantly improve the recording of the audio signals of the person to whom the conversation microphone is attached. Together with the microphones on the front, this can result in a particularly reliable microphone array that can record speakers from different directions with high channel selectivity.

In another variant, the conversation microphone can have a motion sensor for determining the position. In addition, the processor can be programmed to detect the horizontal or vertical position of the conversation microphone from the motion sensor data and to adapt the beamforming algorithm depending on the position. This allows the conversation microphone to react to the different acoustic conditions and select the correct operating mode for the respective position.

According to a further embodiment, the conversation microphone can have charging contacts on its rear side in the rear leg. The charging contacts can preferably be embedded in the housing so that the rear side of the housing remains completely flat. This enables, for example, the device to be charged and operated at the same time. The device can be accommodated in a specially designed charging cradle, which enables the conversation microphone to be used as a table device. Since the charging contacts are provided directly in the rear leg, which also has the battery, a particularly simple design can be achieved in terms of the power supply of the conversation microphone.

Short description of the characters

Fig. 1

eine teilweise aufgerissene schematische Seitenansicht des erfindungsgemäßen Konversationsmikrofons gemäß einer ersten Ausführungsvariante,

Fig. 2

eine schematische Vorderansicht des Konversationsmikrofons aus Fig. 1,

Fig. 3

eine schematische isometrische Ansicht des Konversationsmikrofons aus Fig. 1, und

Fig. 4

eine schematische Ansicht des Konversationsmikrofons aus Fig. 1 im Tragezustand an einer Person.

In the following, preferred embodiments of the invention are presented in more detail with reference to the figures. They show:

Fig.1

a partially opened schematic side view of the conversation microphone according to the invention according to a first embodiment,

Fig. 2

a schematic front view of the conversation microphone from Fig.1 ,

Fig.3

a schematic isometric view of the conversation microphone from Fig.1 , and

Fig.4

a schematic view of the conversation microphone Fig.1 when worn by a person.

Ways to implement the invention

Fig.1 shows a schematic side view of the mobile, portable conversation microphone 1 for the simultaneous recording of several speakers in different channels according to a first embodiment of the invention. The conversation microphone 1 serves in particular as a streaming microphone to record conversations and transmit them via the Internet to servers in the cloud for further processing.

The conversation microphone 1 comprises a housing 2 with a front side 3 and a back side 4. The housing 2 has a front leg 5, which partially forms the front side 3 of the housing 2, and a rear leg 6, which partially forms the back side 4 of the housing 2. The front and rear legs 5, 6 are spaced apart from one another and form a slot 7 as an intermediate space between the legs 5, 6. The legs 5, 6 are in turn connected to one another via a connecting section 8, with the connecting section 8 and the front and rear legs 5, 6 being formed together in one piece to form the housing 2. The connecting section 8 extends both between the front side 3 and the back side 4 and between the end faces 9 of the housing 2 and forms an upper section 10 of the housing 2. The front and rear legs 5, 6 together form a lower section 11 of the housing 2.

The slot 7 extends from the underside 12 of the housing 2 across the middle towards the top side 13 of the housing 2 and extends inside the housing 2 between its end faces 9. In the slot 7, a retaining spring 14 is also provided between the front and rear legs 5, 6, wherein the retaining spring 14 is fastened to one of the two legs 5 or 6 and rests resiliently on the other leg 6 or 5.

The conversation microphone 1 has, as shown in the front view in Fig. 2 As shown, the housing 2 contains a microphone array 15 which has four logically linked microphones 16 in the front 3. In addition, the microphone array 15 has two upward-facing microphones 17 in the top 13 of the housing 2.

The microphones 16 and 17 are arranged in the housing 2 in such a way that they are exposed to the outside and are not covered by components, material, etc. For this purpose, the microphones 16, 17 are preferably provided in recesses in the front 3 and top 13 of the housing 2.

The microphone array 15 is used to record the audio signals of several speakers and is connected to a processor inside the housing 2, which is not shown in detail in the figures. The processor is programmed to use beamforming to record several speakers in to separate different channels. For information on how beamforming works, please refer to the description above.

A loudspeaker is also provided on the top 13 of the housing 2, which emits sound upwards and thus in the direction of the user's ear. This has the advantage that the user can understand well even when the volume is set low, thus ensuring confidentiality.

As further shown in the partially opened view in Fig.1 As shown, the conversation microphone 1 further has a battery 18 inside the housing 2 for supplying power to the processor and all components of the device. The battery 18 is arranged at least partially in the rear leg 6. Preferably, the battery 18 is arranged exclusively in the rear leg 6 and does not extend into the connecting section 8. In an alternative embodiment, the battery 18 can also extend into the connecting section 8.

The battery 18 is arranged in the direction of the rear side 4 behind the central plane 19 of the slot 7. The central plane 19 runs parallel to the inner sides of the front and rear legs 5, 6. As shown in the figures, the central plane 19 also runs parallel to the front side 3 and the rear side 4 of the housing 2. In alternative embodiments, the central plane 19 can also be tilted at an angle to the front side 3 and the rear side 4.

By arranging the battery 18 in the rear leg 6 or behind the central plane 19, the center of gravity of the conversation microphone is shifted towards the back 4, which ensures a stable fit, for example, on an item of clothing 51 of a person 50. The center of gravity, which is particularly far towards the back 4, facilitates a flat contact of the conversation microphone 1 with its back 4 on the body, which can reliably prevent a sudden and unwanted forward tipping. In addition, the conversation microphone 1 can rest on its base 12 in a pocket through the deep slot 7 and be additionally supported, which also further reduces the pull on the item of clothing.

In an alternative design variant, a strap can also be passed through the slot 7, whereby the device can thus be reliably worn around the neck and rests stably on the body.

As in the Fig.1 and 3 shown, operating elements 20, in particular in the form of buttons 20, can be provided in the connecting section 8, i.e. above the slot 7. By arranging the operating element 20 on the front side 9 in the connecting section 8, ensures that the control element 20 can be reached by a person 50 even if the conversation microphone 1 with its slot 7 is placed over a piece of clothing 51.

As in the Fig. 2 and 3 As shown, the conversation microphone 1 in one embodiment variant can also have a display element 21 in the form of a display 21 on its upper side 13. By arranging the display 21 on the upper side 13, the display 21 can remain easily readable even when it is fixed to a person 50, for example to a piece of clothing 51, and can always inform the person 50 about the status of the device or about the current speaker.

In a variant, which is not shown in more detail in the figures, the conversation microphone 1 also has a motion sensor which is connected to the processor and can detect whether the conversation microphone 1 is aligned vertically, for example attached to a person 50, or horizontally, for example lying on a table. Depending on the alignment, the processor can change the control and evaluation of the microphone array 15 so that optimal channel separation between the audio signals of the various speakers is achieved at all times.

In a further embodiment, which is not shown in more detail in the figures, the conversation microphone 1 has 4 charging contacts on its back, which are provided in recesses in the housing 2 so that the back 4 remains completely flat. The charging contacts therefore do not interfere when the conversation microphone 1 is stored flat, for example when it is stored on a table. The flat position means that the operating elements 20 can be operated reliably without the position of the conversation microphone 1 changing and thus impairing the detection of the audio signals. In addition, the conversation microphone 1 can be placed in a suitable charging cradle for charging and for use as a table microphone. In addition, the charging contacts can be connected directly to the battery 18 due to their positioning on the back 4 of the housing 2 in the area of the rear leg 6, which enables a simple construction of the conversation microphone 1.

In Fig.4 is a schematic view of the conversation microphone 1 according to the first embodiment variant in the state worn by a person 50. The conversation microphone 1 is inserted with its slot 7 over a breast pocket 52 of a piece of clothing 51 and is thus firmly fixed to the person 50. The slot 7 is designed in such a way that it can accommodate the piece of clothing 51 or its breast pocket 52. The retaining spring 14 also prevents the conversation microphone 1 from slipping on the piece of clothing 51.

Due to the center of gravity shifted towards the back 4, the conversation microphone 1 rests on the person 50 and is protected from unwanted swaying back and forth. The microphones 17 of the microphone array 15 on the top 13 are directed towards the head of the person 50 and can reliably record the audio signals of the person 50, while the microphones 16 on the front 3 are directed towards another speaker in front of the person 50. In this way, the audio signals of the person 50 and several speakers can be reliably recorded during a conversation.

Claims (10)

1. A mobile, portable conversation microphone for simultaneously recording several speakers in different channels, comprising a housing (2), a microphone array (15) provided in a front side (3) of the housing (2) for recording the audio signals of the speakers, a processor connected to the microphone array (15) and a battery (18) for powering the processor, with the housing (2) having a front leg (5), a rear leg (6) and a connecting section (8), and with a slot (7) being formed between the front leg (5) and the rear leg (6) and the connecting section (8) connecting the front and rear legs (5, 6), characterized in that the battery (18) is at least partially arranged in the rear leg (6), the microphone array (15) comprising at least four microphones (16) spaced apart from each other and connected to the processor which is programmed to separate several speakers from the audio signals of the microphones (16) into different channels, using beamforming, with the connecting section (8) being integrally formed with the front and rear legs (5, 6) and extending between the front side (3) and the back side (4) of the housing (2).
2. A conversation microphone according to claim 1, characterized in that the front leg (5) at least partially forms the front side (3) of the housing (2) and that the rear leg (6) at least partially forms the back side (4) of the housing (2).
3. A conversation microphone according to claim 1, characterized in that the connecting section (8) forms an upper section (10) of the housing (2) and that the front and rear legs (5, 6) jointly form a lower section (11) of the housing (2).
4. A conversation microphone according to any of claims 1 to 3, characterized in that a retaining spring (14) is provided in the slot (7) between the front and rear legs (5, 6).
5. A conversation microphone according to any of claims 1 to 4, characterized in that the slot (7) extends across the centre of the housing (2), starting from the underside (12) of the housing (2).
6. A conversation microphone according to any of claims 1 to 5, characterized in that operating elements (20) and/or display elements (21) are provided in the connecting section (8) on one or more face side(s) (8) and/or on the top side (13) of the housing.
7. A conversation microphone according to any of claims 1 to 6, characterized in that the centre of gravity of the housing (2) is located behind a centre plane (19) of the slot (7) in the direction of the back side (4) of the housing (2).
8. A conversation microphone according to claim 1, characterized in that, on the top side (13), the microphone array (15) additionally has at least two microphones (17) spaced apart from each other and connected to the processor.
9. A conversation microphone according to any of claims 1 to 8, characterized in that the conversation microphone (1) has a motion sensor for determining position.
10. A conversation microphone according to any of claims 1 to 9, characterized in that charging contacts embedded in the housing (2) are provided in the back side (4) of the housing (2) within the rear leg (6).

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