Patent Grant
6990382
The present invention relates to a control system for digital sound effect, and more specifically, to a method and control system for home theater, the system allows the digital control code to be transmitted while transmitting the sound effect data to control the sound effect.
Along with the rapid development of electronic industry, it is not uncommon to play films with advance sound and visual effects on computers anymore. Therefore, the requirement for video and audio performance has become more and more stringent. Except for the need of higher resolution and visual quality, in the field of audio frequency and sound effect, stereo sound effect has gradually replaced mono sound effect. However, the traditional stereo sound effect generates sound through lateral panning of sounds between two speakers to simulate the real three-dimensional sound source movements, and does not actually generate sounds in a three-dimensional space. Another type of surrounding sound generates three-dimensional sounds through multiple speakers, yet it is impossible to precisely locate sounds in a space. Therefore, the sound effect is unsatisfactory.
In recent years, head-related transfer function (HRTF) has been widely used in the field of three-dimensional sound locating technique. Because HRTF simulates the sound effect model heard by a human ear in a three-dimensional space and the parameters corresponding to the three-dimensional sound effect at every spot of the space are determined by its distance, azimuth, and elevation, the listener feel like within the real atmosphere of the sound while playing a film. However, the method of utilizing two sets of speakers to simulate three-dimensional sound effect still exhibits some shortcomings and limitations. For example, those speakers need better frequency response, the positions of the speakers need to be leveled with human ear, the locations of the listener and the speakers should be arranged so as to become an equilateral triangle, the rear surrounding effect should be realistic enough, and the sweet spot which is the area actually generating surrounding sound effect needs to be large enough, otherwise not all people within the space are able to enjoy the sound effect. Therefore, the structure of utilizing four or more speakers is then introduced.
Please refer to
Generally speaking, the family theater system stated above can be controlled by a computer system 102, such as a personal computer (PC), through a sound control unit 1022 (e.g., a sound card) connected with three pairs of transmission lines 122, 124, and 126 to transmit the sound effect data needed by the six stated speakers to a control circuit 108A. Later on, the sound effect data is transferred to FL speaker 110, FR speaker 112, RL speaker 114, RR speaker 116, voice speaker 106, and sub woofer 118 separately through transmission lines 128, 130,132,134, 136, and 138 to generate sound. When the listener 120 watches film, listens to music, or plays computer game, the required three-dimensional sound effect can be realistically generated by the stated sound system 10A. Among the stated speakers, except the sub woofer 118 is used to generate low frequency sound, all the other speakers, including FL speaker 110, FR speaker 112, RL speaker 114, and RR speaker 116, are used to play mid and high frequency sound.
Besides, the conventional sound system 10A can only single-directionally receive and process the sound effect data from the computer system 102, but it can't transmit its status data back to the computer system 102, which is inconvenience while using. For example, human ear can't distinguish the directionality of low frequency sound and is insensitive to low frequency (e.g., 170 Hz) sound. In other words, the wattage of the sub woofer 118 has to increase a great deal for the human ear to sense the difference. On the contrary, human ear is quite sensitive to mid and high (e.g., 1–20 KHz) frequency sounds, therefore the wattage of general sub woofer 118 is much greater than other types of speakers, like the two stated speakers constructed in 40 and 5 watts. On the other hand, most conventional speakers need to be continuously kept at stand-by state and wait for the transmission of sound effect data in order to generate sounds. Therefore, about half (i.e., 50%) of the electrical power provided to the speakers is used to maintain the stand-by state and becomes dissipation heat in order to keep the speakers from burning up caused by overheating. Furthermore, while utilizing the stated speakers, if the listener 120 wants to adjust sound volume or sound quality or even switch the speakers on or off, the computer system 102 is lacking the related assisting user interface or accessories, so as that the listener 120 has to be in front of a speaker and lowers his or her body (or even lie on the floor) to adjust the speaker through control buttons. Some high-end sound and audio systems are equipped with additional extension wires to simplify the adjusting procedure. However, when the listener 120 needs to adjust the sound effect of entire sound field, all speakers need to be undergoing constant adjustment, which is a very inconvenient process. There is a great need for easier sound control system and method in order to overcome the difficulties faced by the prior art.
The object of the present invention is to disclose a control method for sound effect system.
The further object of the present invention is to implant a control code into sound effect data to control the speaker parameters.
The yet object according to the present invention is to provide a communication between the computer system and a sound effect system.
A control method for controlling the sound effect system, comprises implanting a control code into a sound effect data that is transmitted to a sub woofer speaker. Then, the sound effect data with the control code is transmitted to the sound effect system. Next step is to control speakers of the sound effect system by means of the control code. Wherein a data transmission frame between the sound effect system and a computer system for controlling the sound effect system comprises a plurality of bit cells, wherein the data transmission frame includes: a sound effect data transmitted by a data bit; and a control code transmitted by a control bit.
Each the data bit and the control bit is further divided by two sub-units comprises:
a first sub-unit of the data bit used to store a sound effect data transmitted from the computer system to the sound effect system;
a second sub-unit of the data bit used to store a status data transmitted back to the computer from the sound effect system;
a third sub-unit of the control bit used to store a control code transmitted from the computer system to the sound effect system, wherein the control code includes reset pattern; and
a fourth sub-unit of the control bit used to store a confirming code transmitted back to the computer from the sound effect system, wherein the confirming code is used to make sure that the computer system and the sound effect system are in the status of synchronization.
A sampling timing for the controlling method comprises: a first timing cycle utilized to indicate the beginning of data string, each the first timing cycle maintaining at “logic one level”. The computer system indicates the signal by “logic 1” or “logic 0” using a voltage level to transmit data to the sound effect system during the second timing cycle. During the third and the fourth timing cycle, the voltage levels are floating, thus a voltage output by the computer system is slightly higher than the level of “logic 0”. The sampling timing is generated by the phase lock loop (PLL). The third timing cycle is detected by a phase detector (PHD), a mask signal (“logic zero”) is generated to input to an AND GATE via a transmission line, thereby maintaining the voltages level of the transmission line at low level during the third timing cycle to prevent the PLL from being interrupted.
The method further include: fetching the transmitted data by using a data decoder and a timing recorder; composing the fetched transmitted data to from the sound effect data and the control code; and transmitting the sound effect data and the control code to means for playing the sound effect and to means defined by the control code.
The method further comprises following steps to obtain the synchronization frame status between the computer system and the sound effect system:
transmitting a reset pattern from the computer system to the sound effect system by suing a transmission line of the sub woofer speaker;
fetching the reset pattern from the transmission line of a sub woofer speaker by the sound effect system;
recognizing the fetched reset pattern by the sound effect system, if the reset pattern is recognized, then transmitting a synchronization confirming code to the computer system;
fetching the confirming code from the sound effect system by the computer system; and
recognizing the confirming code, if the confirming code is correct, then transmitting control code to the sound effect system.
A control system for controlling a sound effect system by using a digital control signal, comprising a computer system for generating a control code and a sound effect data to control the sound effect system. A control circuits is implanted in the sound effect system to control a playing parameter of the sound effect system according to the control code and the sound effect data. Wherein the control circuits generates a sampling timing in accordance with the control code, thereby creating frame synchronization between the computer system and the sound effect system, wherein the control code is implanted into the sound effect data that is transmitted to a sub woofer speaker.
Wherein each the data bit and the control bit is divided by two sub-units comprises:
a first sub-unit of the data bit used to store the sound effect data transmitted from the computer system to the sound effect system;
a second sub-unit of the data bit used to store a status data transmitted back to the computer from the sound effect system;
a third sub-unit of the control bit used to store a control code transmitted from the computer system to the sound effect system, wherein the control code includes reset pattern; and
a fourth sub-unit of the control bit used to store a confirming code transmitted back to the computer from the sound effect system, wherein the confirming code is used to make sure that the computer system and the sound effect system are in the status of synchronization.
The computer system includes sound effect control unit, the sound effect control unit comprising a PLL (phase lock loop) including a phase detector (PHD) used to generate the sampling timing. A timing recorder is responsive to the phase detector (PHD) to generate a timing signal. A data encoder is responsive to the timing signal to encode a status information of the sound effect system in order to transmit to the computer system via the sub woofer speaker. A data decoder is responsive to the timing signal to decode the control code transmitted via the sub woofer speaker.
A sampling timing is generated by the phase lock loop for controlling, wherein the sampling timing comprises a first timing cycle utilized to indicate the beginning of data string, each the first timing cycle maintaining at “logic one level”. A computer system indicates the signal by “logic 1” or “logic 0” using a voltage level to transmit data to the sound effect system during the second timing cycle. During the third and the fourth timing cycle, the voltage levels are floating, thus a voltage output by the computer system is slightly higher than the level of “logic 0”. The third timing cycle is detected by the phase detector (PHD), a mask signal (“logic zero”) is generated to input to an AND GATE via a transmission line, thereby maintaining the voltages level of a transmission line at low level during the third timing cycle to prevent the PLL from being interrupted.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Turning to
Further, in the
It has to be noted, the computer system 102 may transmits the reset pattern to the sound effect system 10B, continuously, and it may set a predetermined threshold in order to wait for the sound effect system 10B transmits back the synchronization confirming code. When the transmission delaying time (or the number of transmission times) of the transmitted reset pattern is over the threshold, then the computer system 102 transmits the sound effect data by using the conventional method as shown in
The control code may be further divided. For example, the “3C” in the control code “3C5A” may be divided into “00111110”, the former three bits “001” is used as the speaker code and others “11110” is used for the control code to control the vibration of the speaker. In an embodiment, the sub woofer speaker 118, FL-speaker 110, FR-speaker 112, RL-speaker 114, RR-speaker 116 and the voice speaker 106 may be coded as “000”, “001”, “010”, “011”, “100”and “101”, respectively. The aforementioned control code “001” refers to the FL-speaker 110. The definition of the code maybe altered depending on the actual practice. For example, “11110” refers to changing the volume level to 30th level (total 32 volume levels). The above control code “3C” is referred to adjusting the volume level of the FL-speaker 110 to 30th level. Each individual speaker may be controlled by the computer system 102, the user may adjust the playing parameters of each speakers by means of computer system 102. Therefore, the user may change the effect performed by the speakers depending on the locations of each speaker. After the decoding of the control code, the sub woofer speaker 118, FL-speaker 110, FR-speaker 112, RL-speaker 114, RR-speaker 116, the voice speaker 106, volume level and the power are controlled via the transmission line 128, 130, 132, 134, 136 and 138. When the bit number of the reset pattern is reduced to 6 bits, the sound effect system 10B has more vacant bits for speaker playing parameter such as volume level, sound quality and power status.
Next turning to
The signal transmitted on the transmission line 122A is divided into four portions by four times sampling timing CLK—S shown in
On the another hand, during the first timing cycle 402 and the second timing cycle 404, the sound effect system 10B fetches the data from the transmission line 122A and the output is set at the status of floating. Besides, the third timing cycle 408 of the sound effect system 10B also floating and the waveform of the sound effect system 10B is shown in
Next, please turn to
The control circuits 108B fetches the data transmitted by the transmission line 324 via the data decoder 312 and timing recorder 310. After the data of the data transmission frame is fetched, all of the data are composition to from sound effect data and control code, following transmitting by transmission lines 334, 336 to the means for playing the sound effect 316 and to the controlled unit defined by the control code. For example, the “A5” of the control code “3CA5” is used for resetting pattern and the “3C” is used to adjust the volume level of the FL speaker 110 to the 30th level. As aforementioned, the control circuits also includes data encoder 314 to transform the status information and synchronization confirming code of the sound effect system 10B into binary format. When at the falling edge 412 timing recorder 310 transmits the data by transmission line 320 and further transmission the data to computer system 102 via the transmission line 122A.
It has to be note, when the data encoder 314 outputs high level (logic one) during the third timing cycle 406 of the timing CLK—S, the high voltage level pushes the PLL 306 to the status of reset and resulting a calculation error is generated. In order to prevent the issue from being generated, the timing records 310 at the third timing cycle 406 of the timing CLK—S detected by the phase detector (PHD) 3062, a mask signal (“logic zero”) is generated to input to AND GATE 304 via transmission line 324. This makes the voltages level of the transmission line 318 maintains at low level at the third timing cycle 406 of the timing CLK—S, thereby preventing the PLL 306 from being interrupted.
Turning to
After the synchronization, in step 514, the computer system 102 locates the control code needed by the sound effect system 10B into the sound effect data of the sub woofer speaker 118, and the data is transmitted to the sound effect system 10B via the transmission line 122A. All of the signals are respectively transmitted to each speaker via corresponding transmission line. The computer system 102 in step 516 fetches the confirming code and status information transmitted from the sound effect system 10B. Next, the computer system 102 analyzes the confirming code and status information in step 518. Step 520 is to process the necessary function according to the analysis. Step 530 is to determine the playing process is end or not, if the determination is negative, then repeating the flow of steps 514–520.
In step 522, after the sound effect system 10B receives all of the signals for each speaker. The sound effect system 10B fetches the control code by the transmission line 122A of the sub woofer speaker. Then, the sound effect system 10B transmits the confirming code and status information to the computer system 102 via the transmission line 122A in step 526. Next, in step 526, the sound effect system 10B adjusts the status or playing parameter of the speakers, such as volume and the power status, by the instruction of the control code. The speakers perform the data send from the sound effect system 10B. Next step 530 is to determine the playing process is end or not, if the determination is negative, then repeating the flow of steps 514–520.
As is understood by a person skilled in the art, the foregoing preferred embodiments of the present invention are illustrated of the present invention rather than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structure. While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5406634 | Anderson et al. | Apr 1995 | A |
| 5487067 | Matsushige | Jan 1996 | A |
| 5798818 | Derderian et al. | Aug 1998 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20030059057 A1 | Mar 2003 | US |
