JP2770389B2 - Wireless headphone system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless headphone system in which a connection cord is not required by using infrared rays as a transmission medium of an audio signal. Related to charging the next battery.

[Summary of the Invention]

According to the present invention, in a wireless headphone system, demodulation means for demodulating a received signal and supplying an output to a headphone unit, a secondary battery for supplying power to the demodulation means, and supplying a charging current to the secondary battery Having a terminal for transmitting the input signal with predetermined modulation, transmitting the input signal, charging means for charging a secondary battery of the headphone, and electrically connecting the terminal provided on the charging means with the terminal. And a transmitting device having a contact connected to the headphone, by providing an engaged portion to be engaged with an engaging portion provided in the transmitting device in a state where the terminal and the contact are electrically connected to the headphones, The secondary battery on the headphone side can be easily charged.

[Conventional technology]

In a normal wired headphone, a connection cord is extended for a long time, and this connection cord is connected to an audio device, and an audio signal is supplied from the audio device to the headphone via the connection cord.

In such wired headphones, the range of action of a user wearing the headphones is limited by the range of the length of the connection cord. If the user's action range extends beyond the length of the connection cord, there is a problem that the connection cord is pulled and the headphones drop off from the user's head.

In order to solve such problems, for example, Japanese Patent Application Laid-Open
As disclosed in JP-A-82596, a wireless headphone system has been proposed in which an audio signal is transmitted from a transmitting device to a wireless headphone through infrared rays. With this type of headphone system, the user can act over a wide range while wearing the headphones.

[Problems to be solved by the invention]

In the case of a wireless headphone as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 55-82596, a transmitted signal is demodulated and supplied to a headphone unit, and a reproduced signal is obtained from the headphone unit. Therefore, a power supply for operating the demodulation and other circuits is required on the wireless headphone side. If this power source is obtained from the commercial power source, the power cord is derived from the wireless headphones, and the advantages of the wireless headphones are lost.

As the power supply provided on the wireless headphone side,
In consideration of economy, it is preferable to use a secondary battery that can be charged and reused. However, when a secondary battery is used, it is necessary to charge the secondary battery by some method.

A power source that does not require a special charging operation is a solar cell. Therefore, it is conceivable to attach a solar cell to the headphones. However, when using a solar cell, it is necessary to provide a sufficient amount of light for charging. Audio devices are often used indoors, and in the case of solar cells, it is not possible to secure a sufficient amount of light for charging in a dark place indoors. Also, in the case of solar cells, charging cannot be performed efficiently if the light receiving surface is not correctly oriented to the light source, and if the light receiving surface is left undirected to the light source, headphones cannot be used immediately when desired. It takes a long time to charge.

For charging the secondary battery, a general-purpose charger that charges the secondary battery by itself using a commercial power supply is used. When a secondary battery is used as a power source for a wireless headphone, it is conceivable to charge the battery with a general-purpose charger of this type. However, in the case of a general-purpose charger, the secondary battery must be removed as a single unit from the electronic device body each time charging is performed, which is inconvenient in use. In addition, when a general-purpose charger is used, a device may be broken due to an incorrect connection or an incorrect operation of the charger.

In addition, a connector for charging is provided on the electronic device main body, and at the time of charging, a socket of a charger is connected to a charging connector of the electronic device main body to charge a secondary battery inside the electronic device. is there. In such a device, charging can be performed without removing the secondary battery inside the electronic device.

However, even when a charging connector is provided on the device main body and the charger socket is connected to the charging connector of the device main body to perform charging, the charging connector on the device main body side is used every time charging is performed. It must be attached to and detached from the socket on the charger side, which is inconvenient in use.

Therefore, an object of the present invention is to provide a headphone system that can charge a secondary battery on the headphone side without requiring special labor.

[Means for solving the problem]

The present invention includes a demodulating means for demodulating a received signal and supplying an output to a headphone unit, a secondary battery for supplying power to the demodulating means, and a terminal for supplying a charging current to the secondary battery. Headphones, transmitting means for applying a predetermined modulation to an input signal and transmitting the same, charging means for charging a secondary battery of the headphone, and a contact electrically connected to the terminal provided on the charging means. A headphone system comprising: a transmitting device having: a headphone; and an engaged portion that engages with an engaging portion provided on the transmitting device in a state where the terminal and the contact are electrically connected to the headphone.

[Action]

When not using wireless headphones 2,
The top of the hanger part 31 of the wireless headphone 2 is engaged with the engaging recess 15 on the upper part of the transmitting device 1, and the wireless headphone 2 is held on the transmitting device 1. At this time, the engagement recess
The pins 16A and 16B erected at 15 are inserted into the holes 51A and 51B on the bottom surface of the raised portion 33.

As a result, the pins 16A and 16B are brought into contact with the holes 51A and 51B, and the charging power output from the pins 16A and 16B is supplied to the holes 51A and 51B.
A charging current flows to the secondary batteries 45A and 45B in the unit sections 32A and 32B via the contacts in A and 51B.

For this reason, when the top of the hanger 31 of the wireless headphone 2 is engaged with and held in the engagement recess 15 on the upper part of the transmission device 1 when not in use, the two heads in the unit portions 32A and 32B of the wireless headphone 2 are kept. The secondary batteries 45A and 45B are charged. Therefore, there is no need to perform a charging operation each time the device is used, and the trouble of charging is unnecessary.

〔Example〕

 An embodiment of the present invention will be described in the following order.

a. External configuration of transmitting device b. External configuration of wireless headphone c. Internal configuration of transmitting device d. Internal configuration of wireless headphone a. External configuration of transmitting device A transmitting device 1 for modulating and transmitting the FM-modulated audio signal as an infrared signal, a wireless device for receiving an infrared signal from the transmitting device 1, demodulating the received signal, and supplying the demodulated output to a headphone unit And headphones 2.

FIG. 1 shows the configuration of the external appearance of the transmission device 1, and FIG. 2 shows the configuration of the external appearance of the wireless headphones 2.

 First, the configuration of the appearance of the transmission device 1 will be described.

In FIG. 1, a front side surface 11 of a device main body 11 of the transmitting device 1 is shown.
In A, a light emitting element 12 for an indicator and eight infrared light emitting elements 13A to 13H are provided. The light emitting element 12 for the indicator includes the secondary batteries 45A and 4A of the wireless headphone 2.
The state of the charge setting for 5B (FIG. 3) is shown.

That is, as described later, the wireless headphones 2
Are driven by secondary batteries 45A and 45B, and the secondary batteries 45A and 45B of the wireless headphones 2 are charged by using the transmitting device 1. The charging mode includes a normal charging mode and a quick charging mode. In normal charge mode, for example, 50
The secondary batteries 45A and 45B in the wireless headphones 2 are fully charged in a time. In the rapid charging mode, the secondary batteries 45A and 45B in the wireless headphones 2 are fully charged, for example, twice in three hours. The setting of the charging mode is performed by a mode setting switch (not shown) on the rear side surface 11C of the apparatus main body 11. The light emitting element 12 for the indicator is turned on according to the set charging mode and charging state.

From the eight infrared light emitting elements 13A to 13H, infrared signals of FM-modulated audio signals are output. That is,
In the transmission device 1, an audio signal input from the audio device through the connection cord 19 is FM-modulated. This FM modulated audio signal is composed of eight infrared light emitting elements
Output from 13A to 13H.

The eight infrared light emitting elements 13A to 13H simultaneously emit the infrared output of the FM-modulated audio signal because the infrared light output from each of the infrared light emitting elements 13A to 13H has directivity. This is because there is a possibility that an infrared signal from the transmission device 1 does not reach the wireless headphones 2 sufficiently depending on the positional relationship between the transmission device 1 and the wireless headphones 2 using only one infrared light emitting element. Thus, by using the eight infrared light emitting elements 13A to 13H, the directivity of the emitted infrared signal is lost, and the arrival area is expanded.

An engagement recess 15 is provided on the upper surface 11B of the device main body 11. The size of the engagement concave portion 15 corresponds to the width of a raised portion 33 at the top of a hanger portion 31 of the wireless headphone 2 described later. In this engagement recess 15, two pins 16A
And 16B are planted. These pins 16A and 16B correspond to the positions of two holes 51A and 51B (FIG. 5) on the bottom surface of the raised portion 33 of the hanger portion 31 of the wireless headphone 2. The two pins 16A and 16B serve as charging power supply terminals for charging the secondary batteries 45A and 45B of the wireless headphones 2 using the transmitting device 1.

A connection cord 18 of a power supply adapter 17 is led out from a rear side surface 11C of the apparatus main body 11. The power adapter 17 is attached to a commercial power outlet. Further, a cord 19 for connection to audio equipment is led out from a rear side surface 11C of the device main body 11. A plug 20 attached to the end of the audio connection cord 19 is connected to an output terminal of an audio device such as a compact disk player or a cassette tape recorder.

This apparatus main body 11 is arranged on a base 21. Equipment body
The elevation angle of 11 with respect to the base 21 can be freely changed about the axis 22. By adjusting the elevation angle of the device main body 11 with respect to the base 21, the reception sensitivity of the wireless headphones 2 can be adjusted optimally.

b. Configuration of the appearance of the wireless headphones Next, the configuration of the wireless headphones 2 will be described.

As shown in FIG. 2, the wireless headphone 2 has a configuration in which left and right unit portions 32A and 32B are attached to a hanger portion 31. At the top of the hanger part 31, a raised part 33 is provided.
Is formed.

The wireless headphones 2 include three light receiving elements 3
4, 35A and 35B are provided. These light receiving elements 34 and 35A
And 35B, the infrared light emitting elements 13A to 13H of the transmitting device 1
The infrared signal sent from the device is received.

The light receiving element 34 is provided on the raised portion 33 toward the rear side. The light receiving elements 35A and 35B are provided in the unit sections 32A and 32B,
Each is arranged toward the front lower side.

By arranging the light receiving elements 35A and 35B toward the front lower side, when the user is wearing the wireless headphones 2 in a natural state, the light is transmitted from the infrared light emitting elements 13A to 13H of the transmitting device 1. Infrared signals can be received optimally. In addition, disposing the light receiving elements 35A and 35B toward the front lower side can prevent the light receiving elements 35A and 35B from being hidden by the hair. On the other hand, the light receiving element 34 is
The infrared signal from the infrared light emitting elements 13A to 13H of the transmitting device 1 reflected from the wall and sent is optimally received.

As shown in FIG. 3, the exterior of the unit 32A (32B) is covered by a housing 41A (41B). A light receiving window 42A (42B) is formed in a part of the housing 41A (41B), and the light receiving element 35A (35B) is formed through the light receiving window 42A (42B).
In B), an infrared signal is received. Unit 35A (35B)
An ear pad 43A (43B) is provided in a portion to be attached to the ear. As shown in FIG. 4, the ear pad 43A (43B) has a urethane foam 46A (46B) and a skin 47A (4B).
7B).

As shown in FIG. 4, a headphone unit 44A (44) is provided in the housing 41A (41B) of the unit sections 32A and 32B.
B) is provided, and a secondary battery 45A (45B) such as a nickel cadmium battery is provided. This secondary battery 45A
(45B) is a power source for driving the wireless headphones 2. A power supply voltage of, for example, 2.4 V can be obtained by connecting the left and right secondary batteries 45A (45) in series.

As shown in FIG. 5A, a hole 51 is formed in the bottom of the raised portion 33.
A and 51B are provided. The holes 51A and 51B are provided at positions corresponding to the pins 16A and 16B in the engagement recess 15 of the apparatus main body 1. In the holes 51A and 51B, contact points for contacting the pins 16A and 16B are provided. The holes 51A and 51B serve as terminals for inputting a power supply for charging.

As shown in FIG. 5B, a switch 52 for setting the charge on / off is provided on the rear side surface of the raised portion 33. The switch 52 for setting the charge on / off sets the charge on / off of the rechargeable batteries 45A and 45B in the unit sections 32A and 32B, and the holes 51A and 51B on the bottom surface of the protruding section 33. It is opened and closed in conjunction with the switch 52.

In this embodiment, when not in use, the top of the hanger part 31 of the wireless headphone 2 is engaged with the engaging recess 15 on the upper part of the transmitting device 1, and the wireless headphone 2 is held on the upper part of the transmitting device 1.

At the time of use, the wireless headphones 2 held in the engagement recess 15 on the upper part of the transmitting device 1 are detached, and the wireless headphones 2 are worn on the ears of the user.

When the top of the hanger section 31 of the wireless headphone 2 is engaged with the engagement recess 15 at the top of the transmitting device 1 when not in use, as shown in FIG.
A and 16B are inserted into holes 51A and 51B on the bottom surface of the raised portion 33. At this time, the charge on / off setting switch 52 on the rear surface of the raised portion 33 is set to the charge on side, and the holes 51A and 51B are open.

As described above, when the top of the hanger 31 of the wireless headphones 2 is engaged with and held in the engagement recess 15 on the upper part of the transmission device 1 when not in use, the pins 16A and 16B become holes 51A and 51B.
Is contacted. Thereby, the charging power output from the pins 16A and 16B is supplied to the secondary batteries 45A and 45B in the unit sections 32A and 32B via the contacts in the holes 51A and 51B.

For this reason, when the top of the hanger 31 of the wireless headphone 2 is engaged with and held in the engagement recess 15 on the upper part of the transmission device 1 when not in use, the two heads in the unit portions 32A and 32B of the wireless headphone 2 are kept. The secondary batteries 45A and 45B are charged. Therefore, there is no need to perform a charging operation each time the device is used, and the trouble of charging is unnecessary.

The holes 51A and 51B on the bottom surface of the raised portion 33 of the wireless headphone 2 are linked with the switch 52, and the holes 51A and 51B are closed at the time of charging off when the wireless headphone 2 is used. This is to prevent dust and oil of hair from entering through the holes 51A and 51B.
If dust or hair oil enters through the holes 51A and 51B, it may cause poor contact.

In this embodiment, when inserting the pins 16A and 16B of the engaging recess 15 of the apparatus main body 11 into the holes 51A and 51B on the bottom surface of the raised portion 33 of the wireless headphone 2, it is not necessary to consider the polarity. That is, as shown in FIG. 7, a full-wave rectifier circuit 56 for rectifying power from the contacts 55A and 55B of the holes 51A and 51B of the wireless headphone 2 is provided in the wireless headphone 2. The rectified power is supplied to the secondary batteries 45A and 45B in the unit sections 32A and 32B of the wireless headphone 2 via the rectified power. Since such a full-wave rectifier circuit 56 is provided, it is possible to prevent a wrong polarity at the time of charging.

c. Internal Configuration of Transmitting Device The internal configuration of the transmitting device 1 and the wireless headphones 2 will be described.

FIG. 8 shows the configuration of the transmission device 1. 8th
In the figure, left and right audio signals are supplied to input terminals 61A and 61B, respectively. This audio signal is passed through emphasis circuits 62A and 62B, respectively, and further supplied to FM modulation circuits 64 and 64B via AGC circuits 63A and 63B, respectively.

This audio signal is FM-modulated by FM modulation circuits 64A and 64B. The carrier frequency at this time is different between the left and right audio signals. The left audio signal
The carrier frequency at the time of FM modulation is, for example, 2.3 MHz. The carrier frequency at the time of FM-modulating the right audio signal is, for example, 2.8 MHz.

The output of the FM modulation circuits 64A and 64B is a bandpass filter 65.
The signals are supplied to buffers 66A and 66B, each of which includes an emitter follower transistor, via A and 65B, respectively.
The outputs of the buffers 66A and 66B are supplied to the LR mixing circuit 67.

The LR mixing circuit 67 mixes the left FM-modulated audio signal output via the buffer 66A with the FM-modulated right audio signal output via the buffer 66B. Infrared light emitting element
13A to 13H. This LR mixing circuit 67
It is composed of transistors 71 to 74.

That is, the collectors of the transistors 71 and 72 have 4
The series connection of the infrared light emitting elements 13A to 13D is connected, and the collectors of the transistors 73 and 74 are connected to the series connection of four infrared light emitting elements 13E to 13H. Transistor 71
And 74 are supplied with the left-side FM-modulated audio signal output via the buffer 66A. The right side FM-modulated audio signal output via the buffer 66B is supplied to the bases of the transistors 72 and 73.

The infrared light emitting elements 13A to 13H output infrared signals obtained by FM-modulating the left and right audio signals. As the infrared ray, for example, one having a wavelength of 850 nm is used.

d. Internal configuration of wireless headphones FIG. 9 shows an internal configuration of the wireless headphones 2. In FIG. 9, the raised portion 33 and the unit portion
The three light receiving elements 34, 35A, and 35B in 32A and 32B receive infrared rays from the infrared light emitting elements 13A to 13H of the transmitting device 1. Outputs of the light receiving elements 34, 35A and 35B are supplied to an LR separation circuit 83 via a band pass filter 81 and an RF amplifier 82.

The LR separation circuit 83 separates the left and right FM modulated audio signals. The left and right FM-modulated audio signals are supplied to FM front ends 84A and 84B, respectively.
In the FM front ends 84A and 84B, the FM modulated audio signal is converted into a signal of a predetermined intermediate frequency. This intermediate frequency signal is supplied to FM intermediate frequency amplifier circuits 86A and 86B via ceramic filters 85A and 85B, respectively. The output of FM intermediate frequency amplifier circuits 86A and 86B is FM demodulation circuit
It is supplied to 87A and 87B, respectively.

The FM demodulation circuits 87A and 87B perform FM demodulation on the outputs of the FM intermediate frequency amplification circuits 86A and 86B, and left and right audio signals are obtained from the demodulated outputs. The left and right audio signals are supplied to audio output amplifiers 88A and 88B, respectively. The outputs of the audio output amplifiers 88A and 88B are supplied to the left and right headphone units 44A and 44B, respectively.

Further, demodulated outputs from the FM demodulation circuits 87A and 87B are supplied to high-pass filters 90A and 90B, respectively. High-pass components in the demodulated output are extracted by the high-pass filters 90A and 90B. This high-frequency component corresponds to a noise component that causes harshness. Outputs of the high-pass filters 90A and 90B are supplied to detection circuits 91A and 91B, respectively. Detection circuit 91
At A and 91B, the level of the high frequency component in the demodulated output is detected. As a result, a high-frequency noise level that causes harshness during demodulation output is detected.

The outputs of the detection circuits 91A and 91B are supplied as switch control signals to the switch circuits 92A and 92B, respectively. The audio output amplifier 88 is controlled by the switch circuits 92A and 92B.
On / off of muting of A and 88B is controlled.

When the distance between the transmitting device 1 and the wireless headphones 2 increases, the infrared signal from the transmitting device 1 hardly reaches the wireless headphones 2, and the level of the noise component with respect to the signal being demodulated and output increases. As a result, the detection levels of the detection circuits 91A and 91B increase. Detection circuit 91
When the detection levels of A and 91B increase, the switch circuit 92
A and 92B are turned on, for example, to mute the output amplifiers 88A and 88B.

Thus, in this embodiment, mute is applied according to the level of the high frequency component of the demodulated output. For this reason, it is possible to remove high-frequency component noise that is particularly annoying when the received signal is weakened.

〔The invention's effect〕

According to the present invention, when the wireless headphones 2 are not used, the top of the hanger portion 31 of the wireless headphones 2 is engaged with the engaging recess 15 on the upper part of the transmitting device 1, and the wireless headphones 2 are placed on the transmitting device 1. Will be retained. At this time, the pins 16A and 1
6B is inserted into holes 51A and 51B on the bottom surface of raised portion 33.

As a result, the pins 16A and 16B are brought into contact with the holes 51A and 51B, and the charging power output from the pins 16A and 16B is supplied to the holes 51A and 51B.
The power is supplied to the secondary batteries 45A and 45B in the unit sections 32A and 32B via the contacts in A and 51B.

For this reason, when the top of the hanger 31 of the wireless headphone 2 is engaged with and held in the engagement recess 15 on the upper part of the transmitting device 1 when not in use, the two heads in the unit portions 35A and 35B of the wireless headphone 2 are kept. The secondary batteries 45A and 45B are charged. Therefore, there is no need to perform a charging operation each time the device is used, and the trouble of charging is unnecessary.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external configuration of a transmitting apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing an external configuration of a wireless headphone according to an embodiment of the present invention, and FIG. FIG. 4 is a perspective view illustrating a wireless headphone according to an embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating a wireless headphone according to an embodiment of the present invention.
5A and 5B are a bottom view and a side view for explaining a wireless headphone according to an embodiment of the present invention. FIG. 6 is a perspective view for explaining an embodiment of the present invention. FIG. 8 is a connection diagram used for describing a charging circuit, FIG. 8 is a block diagram showing a configuration of a transmission device according to an embodiment of the present invention, and FIG. 9 is a block diagram showing a configuration of a wireless headphone according to an embodiment of the present invention. is there. Description of main reference numerals in the drawings 1: transmission device, 2: wireless headphone, 13A to 13H: infrared light emitting element, 15: engagement recess, 16A, 16B: pin, 31: hanger part, 32
A, 32B: Unit, 34, 35A, 35B: Light receiving element, 51A, 51B: Hole

Claims (1)

(57) [Claims] 1. A demodulation means for demodulating a received signal and supplying an output to a headphone unit, a secondary battery for supplying power to the demodulation means, and a terminal for supplying a charging current to the secondary battery. A transmitting means for performing predetermined modulation on an input signal and transmitting the same, a charging means for charging a secondary battery of the headphones,
A transmission device having a contact electrically connected to the terminal provided on the charging means; and an engagement provided on the transmission device with the terminal and the contact electrically connected to the headphones. A headphone system comprising a portion and an engaged portion that engages with the portion.