Patent Application
20100054508
This application claims the priority benefit of Taiwan application serial no. 97215717, filed on Sep. 1, 2008. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.
1. Field of the Invention
The present invention generally relates to a multiple-channel wireless earphone device, and more particularly to a wireless earphone device with a stereo or multiple-channel sound effect automatic detection and switching functions.
2. Description of Related Art
With the rapid development of digital technologies, the entertainments in people's daily life has also gradually become more digitized. For example, a Digital Versatile Disc (DVD) player has been a common video playback device in most families. As most DVD players have equipped with Dolby Digital or Digital Theater System (DTS) decoding function, the DVD players can be used to decode digital signals, and output analog signals to multiple-channel amplifiers, so as to enable 5.1 channel speaker systems to produce sounds.
A multiple-channel amplifier and speakers are indispensable for realizing a high-quality digital audio-visual entertainment. The 5.1-channel speakers are the most basic multiple-channel speakers.
Generally, in a home theater system including a 5.1-channel amplifier and speakers, when the DVD player plays audio-visual programs, the amplifier amplifies different sound signals and outputs them to main front left and right speakers, center speaker, surround (or rear) left and right speakers, and sub woofer respectively, so as to produce a three-dimensional sound effect that sounds real to the audience.
However, in the case that the speakers cannot be used (for example, the sounds produced by the speakers may influence somebody else who are doing their work), then an earphone is needed. As the earphone must be connected to a playback device via a wire to transmit signals, the movement of the listener is limited, that is, the listener cannot move around freely.
In U.S. Pat. No. 6,614,912 and U.S. Pat. No. 6,928,179, an infrared wireless earphone is disclosed. The operating principles thereof are described as follows: a multiple-channel sound effect is processed into signals of left and right channels through a signal processing procedure, and then the signals are transmitted to the earphone wirelessly, and then two speakers in the earphone are used to present a virtual multiple-channel sound effect. However, the virtual sound effect generated by such architecture is not a real multiple-channel effect. In addition, the transmission distance of the infrared wireless technology is rather short, and the infrared rays cannot penetrate objects that blocks the way, which further restricts the transmission range.
In U.S. Patent Publication No. 2006/0287745, a wireless audio system using infrared transmission is provided. The wireless audio system is mainly used to select from a plurality of sound sources, decode the received signals, and generate a multiple-channel sound effect. However, the earphone must be configured with decoders for a plurality of sound sources at the same time, so the structure thereof is very complicated. In addition, when the received signals are processed, the signal delays for different signals must be considered, for example, when the high-quality signals of the 5.1-channel sound source are processed, the delay problem may occur. Furthermore, as the infrared transmission is adopted, the transmission distance is also restricted. Therefore, such disclosure is limited to a wireless audio system applied in an automobile.
In addition, in the Taiwan Patent Application No. 200603652, a multiple-channel wireless audio system is provided, which includes a receiving unit for receiving and demodulating wireless multiple-channel sound signals. In this patent application, a receiving circuit is added at an earphone end, and after a signal is obtained through demodulation and spread spectrum methods, the multiple-channel sound signal is decoded to a plurality of signals of different channels by a decoder. Then, a sound mixer and signal processor mixes and processes the signals of different channels to generate a plurality of mixed sound signals with different stereo effects, which are then sent to speakers to produce sounds. Though this architecture achieves a desirable wireless transmission range, the signal transmission becomes rather complicated. Moreover, the received demodulated signals must be decoded by the decoder, and during this process, the signal content of the 5.1-channel sound source may not be effectively decoded due to transmission errors, which relatively influences the quality of signal transmission. Besides, if the functions of the earphone end are too complicated, the earphone end cannot meet the design requirements of being light, thin, short, and small.
The design of the multiple-channel wireless earphone device must be capable of eliminating the limitations caused by topographic features and objects within the effective wireless transmission range of signals, and must have a high noise tolerance to the transmitted content. Furthermore, the modern design requirements of being light, thin, short, and small must be considered as well.
Accordingly, the present invention is directed to a multiple-channel digital wireless earphone device, and more particularly to a wireless digital earphone device with stereo or multiple-channel sound effect automatic detection and switching functions.
As embodied and broadly described herein, a multiple-channel digital wireless earphone device is provided in the present invention, in which multiple-channel signal sources are decoded at a transmitting end, and then they are transmitted to an earphone end through a radio. After being digital-to-analog converted and amplified, the multiple-channel signals are connected to a plurality of speakers to generate a multiple-channel surround sound field. Furthermore, the earphone device at a receiving end meets the requirements of being light, thin, short, and small.
A multiple-channel digital wireless earphone device is provided in the present invention, which can automatically detect received sound source signals, determine whether the sound source signals are 6CH or 2CH, and automatically select a corresponding earphone playing mode. If the sound source signals are 6CH, that is, a 5.1-channel surround sound effect, signals of different channels are respectively connected to the main front speakers, sub woofers, center speaker, and surround speakers in the multiple-channel earphone. Furthermore, if the sound source signals are 2CH, that is, a stereo sound effect, the signals are concurrently connected to the main front left and right speakers, and left and right sub woofers, or a combination of a plurality of other speakers, instead of being merely connected to the main front speakers, thereby achieving different sound field effects.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Besides eliminating the limitations caused by topographic features and objects within the effective wireless transmission range of signals, the design of the multiple-channel digital wireless earphone device is further required to have a high noise tolerance to the transmitted content. Furthermore, the modern design requirements of being light, thin, short, and small must be considered as well.
In the multiple-channel digital wireless earphone device of the present invention, multiple-channel signal sources are decoded at a transmitting end, and then they are transmitted to an earphone end wirelessly. After being directly digital-to-analog converted and amplified, the multiple-channel signal sources are connected to a plurality of speakers to generate a multiple-channel surround sound field. Furthermore, the earphone device at a receiving end meets the requirements of being light, thin, short, and small.
The multiple-channel wireless earphone device of the present invention is suitable for being connected to a 5.1-channel sound source (briefly called 6CH sound source hereinafter) output by a Digital Versatile Disc (DVD) player or connected to a stereo sound source (briefly called 2CH sound source hereinafter).
For example, when the earphone device receives the 6CH sound source digitally output by the DVD player or provided by a video game console, a decoding circuit in the transmitter decodes the 6CH sound source, and wirelessly transmits the 6CH sound source to 5.1-channel earphones in a digital manner for playback. The output signals include three groups of signal sources, for example, front signals, rear signals, and a center signal/a sub woofer signal.
However, when the received signals are 2CH stereo sound source, for example, signals of the 2CH sound source provided by the DVD player, or a sound source in a linear pulse code modulation (LPCM) format, the multiple-channel digital wireless earphone device of the present invention concurrently connects the amplified signals to at least two groups of speakers in the multiple-channel earphone for playback. Based on different combinations of the speakers in the multiple-channel earphone, a sound with the sound field separation effect is generated, such that the original 2CH stereo sound source produces different sound field effects.
The multiple-channel digital wireless earphone device of the present invention can automatically detect received sound source signals, determine whether the sound source signals are 6CH or 2CH, and automatically select a corresponding earphone playing mode accordingly. If the sound source signals are 6CH, that is, a 5.1-channel surround sound effect, signals of different channels are respectively connected to main front speakers, sub woofers, central speaker, and surround speakers in the multiple-channel earphone. Furthermore, if the sound source signals are 2CH, that is, a stereo sound effect, the signals are concurrently connected to main front left and right speakers and left and right sub woofers or a combination of a plurality of other speakers, instead of being merely connected to the main front speakers, thereby achieving different sound field effect.
The multiple-channel wireless earphone device of the present invention includes a signal processing and transmitting device and a wireless earphone with a receiving device. An embodiment of the present invention is described below with reference to
In the signal processing and transmitting device 100, the automatic input selector 110 has a coaxial circuit connection interface and an optical fiber connection interface, which are respectively connected to a coaxial digital signal input source from a coaxial circuit and an optical fiber digital signal input source from an optical circuit. The automatic input selector 110 can detect and automatically switch between digital signal sources, and output the received signals to the DSP 120.
The optical fiber connection interface may be in the Sony/Philips Digital Interface (S/PDIF) format, in which an optical fiber connection circuit satisfying the S/PDIF specifications connects signals to a multiple-channel decoder to generate a surround sound field effect such as Dolby Digital and Digital Theater System (DTS) or a stereo sound field effect. Dolby Digital and DTS are both multiple-channel audio formats widely applied in 5.1-channel audio systems currently. The S/PDIF format with the full name of Sony/Philips Digital Interface is a specification developed under the cooperation of both Sony and Philips. The S/PDIF includes two connection types. The first type uses an unbalanced RCA connector and 75-ohm coaxial signal cables, and the second type uses optical fibers. The S/PDIF is the most common digital signal format in home specifications, for example, digital audio recording and playing of Mini Disk (MD) and surround digital output of DVD players. In this embodiment, the S/PDIF connection port is used.
The DSP 120 is responsible for decoding the multiple-channel digital sound effect. The DSP 120 includes built-in decoding software, for processing Dolby Digital 5.1, Dolby Digital 2.0, Dolby Pro Logic, LPCM (stereo), or DTS encoded signals to output multiple-channel signals. The multiple-channel signals include three groups, for example, front signals, rear signals, and a center signal and sub woofer signal. In the multiple-channel wireless earphone device of the present invention, the DSP 120 at the transmitting end decodes the signals, and connects the obtained three groups of digital signals (including: 1. the front signals, 2. the rear signals, and 3. the center signal and sub woofer signal) to the wireless communication module 130, in which the three groups of signals are transmitted concurrently over a group of antennas 132 and 134. For example, the wireless communication module 130 may be a 2.4 GHz RF radio transmitter.
The signal processing and transmitting device 100 further includes the microcontroller 140 and the wireless communication module microcontroller 150, which control the operations of the DSP 120 and the wireless communication module 130 respectively. In addition, the voltage regulator 160 obtains a DC voltage source from the DC voltage input 170, for example, a 7.5 V voltage as shown in
The receiving end of the multiple-channel wireless earphone device according to the present invention is a wireless earphone containing a receiving device.
The operating voltage of the wireless communication module 210, the wireless communication module microcontroller 216, the 6-channel DAC 218, the microcontroller 228, and the display module 232 are supplied by the +3.3V voltage regulator 236. The voltage source of the +3.3V voltage regulator 236 is the rechargeable battery 234, which may be charged by the earphone charging circuit 172 as shown in
To accomplish the function of automatically detecting the 6CH and 2CH sound sources, the present invention further includes an input format detector 240 and a sub/front speaker select switch 242 in an alternative embodiment.
The wireless communication module 210 works together with the wireless communication module 130 of the signal processing and transmitting device 100 to transmit and receive signals. When the wireless communication module 130 transmits the three groups of digital signals including the front signals, the rear signals, and the center signal and the sub woofer signal through an RF radio at a frequency band of 2.4 GHz, the wireless communication module 210 uses its own 2.4 GHz RF radio receiver to receive the three groups of signals concurrently, and connects them to the 6-channel DAC 218.
In this embodiment, as the wireless earphone 200 may be optionally provided with a microphone 238, the earphone 200 must further include a radio transmitter, besides the radio receiver. The wireless communication module 130 shown in
The 6-channel DAC 218 is mainly used to convert the three groups of digital signals including the front signals, the rear signals, and the center signal and the sub woofer signal into analog signals.
The microcontroller 228 is responsible for setting a working mode for the 6-channel DAC 218, including volume control and status monitoring, and informing messages such as decoder volume setting and decoding format to the user through the display module 232. The control panel 230 offers various options, such as main volume control, volume control of the center channel and surround channels, volume reset, and mute.
The 6-channel earphone amplifier 220 amplifies the analog signal outputs from the 6-channel DAC 218 to drive the 5.1-channel earphones. The delay circuit 224 blocks the surge current from the amplifier to the speakers generated at the instance when the earphone is powered on, so as to protect the user's ears from being hurt.
The input format detector 240 determines whether the music format is 5.1-channel format or stereo format, and generates a control signal to the sub/front speaker select switch 242 according to the music format, so as to control and adjust the speaker configuration, thereby achieving the best audio effect. The sub/front speaker select switch 242 connects the bass to the left and right sub woofers when the input sound source is in the 5.1-channel format. When the input sound source is in the stereo format, the left front and right front outputs are respectively connected to the left and right sub woofers, so as to enhance the effect of the stereo music. At this time, the center and rear surround channels have no output.
The multiple-channel wireless earphone device of the present invention may adopt a design of a non-fixed microphone, which is connected to the earphone device, for example, through a jack. For example, the connection jack between the microphone and the earphone device is a conductive device, the microphone is a gooseneck microphone, and a connecting end of the microphone may be directly inserted into the jack, so as to establish the electrical connection there-between.
In addition, the microphone 238 and the wireless earphone 200 may also be fixed together by adding a magnet to the connection interface, so as to attract and fix the microphone 238 on the wireless earphone 200. When the microphone 238 is not used, it can be removed from the wireless earphone 200.
In addition, two grooves 320 for accommodating a wireless earphone 305 are disposed on a body 310 of the signal processing and transmitting device 300. A connection interface 322 for electrically connecting the wireless earphone 305 is disposed in each groove, for example, the connection interface 322 is a plurality of pins. In addition, the signal processing and transmitting device 300 further includes a battery slot 330, which is provided for a battery 370 to be inserted therein and supplies power to the battery 370, and it is equivalent to the DC voltage input 170 of
Two indicators 340 and 350 are disposed on one side of the body 310. The indicator 340 indicates a charging status of the wireless earphone 305, and the indicator 305 indicates whether the power is supplied or not currently. The indicators 340 and 350 may be light-emitting diode (LED) display devices. A connection interface 360 is disposed on the other side of the body 310. The connection interface includes a plurality of connection jacks for connecting different sound sources, for example, an optical fiber connection interface in the S/PDIF format, or a coaxial signal cable interface with an unbalanced RCA connector. In addition, a universal serial bus (USB) connection interface, for example, may also be used to connect signals.
When the two earphone ends of the wireless earphone 305 are respectively accommodated into the grooves 320, the wireless earphone 305 may be charged by the earphone charging circuit in the signal processing and transmitting device 300. Here, the charging mode of electrical contacts is introduced. Certainly, the charging mode of electromagnetic induction may also be adopted.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 97215717 | Sep 2008 | TW | national |
