JP2008022127A - Surround device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surround device capable of preventing poor quality in sound output by detecting poor quality in an input signal caused by poor quality or the like in the connection of a voice cable. <P>SOLUTION: When one of detection signals 21, 22 from input signal detectors 13, 14 is high, a microcomputer 19 sends an instruction signal 23 for instructing a surround circuit 15 to be turned to a surround-off state. The surround circuit 15 does not generate any pseudo stereo signals, and inputs an audio input signal to a sound amplifier 16 as it is for driving speakers 17, 18. In this case, an instruction signal 24 for performing the OSD-display of caution/warning for canceling the surround is displayed on a display unit 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surround device having a simple surround function for a 2ch stereo signal, and more particularly to a surround device capable of preventing an audio output failure due to an audio cable connection failure or the like.

  Conventionally, there is a surround technology that can easily generate a surround effect with two left and right speakers (see Patent Document 1). Since this technique can easily obtain a surround effect with two speakers, it is used in, for example, a television receiver.

  FIG. 3 is a block diagram of this surround circuit. This surround circuit includes a pseudo stereo circuit 50 that generates pseudo stereo signals LS and RS based on the left and right audio signals L and R, an attenuation circuit 51 that attenuates the pseudo stereo signals LS and RS, and a pseudo stereo signal as the left and right audio signals L and R. Addition circuits 52 and 53 for adding LS and RS, and speakers 54 and 55 are provided.

  The pseudo stereo circuit 50 generates pseudo stereo signals LS and RS for forming reverberation sound and reflection sound from the rear based on the left and right audio input signals L and R. The pseudo stereo signals LS and RS are the sum and difference of the left and right audio input signals L and R. Then, the signal is attenuated by the attenuation circuit 51, and the pseudo stereo signal LS is added to the left audio input signal L and the pseudo stereo signal RS is added to the right audio input signal R.

  When the same sound by the same signal is generated from the left and right speakers 54, 55, the sound is localized at the center of the speakers 54, 55. However, since the pseudo stereo signals LS and RS are not the same signal, the same signal is not generated from the speakers 54 and 55, and the sound is not localized at the center of the speakers 54 and 55. Then, there is a difference in the time for the pseudo stereo signals LS and RS to reach the viewer, and it sounds as if the pseudo stereo signals LS and RS are reflected backward.

Thus, the surround effect is generated by applying the pseudo stereo signal generated based on the input signal to the input signal again. The pseudo stereo signal is not limited to the above, and may be a sum only or a difference only.
JP 2000-102100 A

  The surround effect is produced when the left and right audio input signals are normally input. However, when a user connects a cable to a connection terminal, for example, when an audio signal (stereo L / R) is input from an external audio device, the connection failure state of the cable to the connection terminal may not be noticed. There is a possibility that only one of the left and right audio input signals is not input due to poor connection. In the worst case, the input signal is doubled and output from one speaker, which may cause a worse audio output defect than in the normal mode in which no surround processing is performed.

Assume that only the input signal L is input and the input signal R is zero in the surround circuit of FIG. Here, assuming no attenuation,
・ Signal to the speaker 54 = | L + R | + L = 2L
・ Signal to speaker 55 = | L−R | + R = L
It becomes.

  That is, one speaker outputs a signal twice as large as the input signal, and the other speaker leaks the input signal as it is. Therefore, the volume of the other speaker is larger than the volume of one speaker, and a volume difference occurs between the left and right (the stereo sense is lost and the sound quality is different). If the TV becomes high in this state, even if there is no abnormality in the sound output from the speaker on the signal non-input side, the sound output is doubled on the signal input side speaker, sound distortion occurs, and the speaker or sound circuit A high load is applied.

  In view of the above problems, the present invention is to provide a surround device that can detect a failure of an input signal due to a connection failure of an audio cable or the like and prevent an audio output failure.

The present invention relates to a surround apparatus that obtains a sum or difference of left and right audio input signals and adds the input signals to the input signals to produce a surround effect using left and right speakers.
When the input signal detection means for detecting the presence or absence of the left and right audio input signals, the surround means for generating a surround signal for producing a surround effect, and the input signal detection means detect that one of the signals is not input, And control means for turning off the surround means.

  Further, the control means performs a warning warning to the user using the warning notification means when the surround means is turned off. Further, the control means may be performed by displaying a warning warning on the warning notification means.

Thus, the present invention detects the input of the audio signal of the left and right audio input signals, and if only one of the input signals is input at the time of surround selection, it does not cause surround, so one speaker Therefore, it is possible to prevent distortion from occurring due to an increase in output from the speaker, and high load on the speaker and the audio circuit.
In addition, since a warning warning is displayed to the user, the user can recognize the reason why the surround function cannot be used.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of a liquid crystal television receiver incorporating a surround device according to the present invention. FIG. 2 is a flowchart showing a procedure for detecting a connection failure to prevent a sound failure.
This surround device includes external input terminals 11 and 12, input signal detectors 13 and 14 that detect input signals to the external input terminals 11 and 12, a surround circuit 15 that generates a simple surround signal, and audio that amplifies the signal. An amplifier 16, speakers 17 and 18, a microcomputer 19 that controls each unit, and a display unit 20 are provided. Of course, the liquid crystal television receiver has a receiving portion and a display control portion, but the description thereof is omitted here.

  The left audio input signal input from the external input terminal 11 is L, and the right audio input signal input from the external input terminal 12 is R. When the audio input signals L and R are input, a voltage of a certain level or higher is applied. The input signal detectors 13 and 14 detect whether the input signals L and R have a voltage equal to or higher than a certain level, and send detection signals 21 and 22 to the microcomputer 19.

  Here, the input signal detection unit 13 is composed of resistors 31, 32, and 33 and a transistor 34, and the input signal detection unit 14 is a circuit composed of resistors 35, 36, and 37, and a transistor 38. The external input terminal 11 is connected to the base of the transistor 34 via the resistor 32, and is connected to one end of the resistor 31, and the other end of the resistor 31 is grounded. Further, one end of the resistor 33 is connected to the collector of the transistor 34, and a voltage + V is applied to the other end. The emitter of the transistor 34 is grounded. The external input detection signal 21 is taken out from the emitter of the transistor 34. Similarly, the external input terminal 12 is connected to the base of the transistor 38 via the resistor 36, connected to one end of the resistor 35, and the other end of the resistor 35 is grounded. Also, one end of the resistor 37 is connected to the collector of the transistor 38, and the voltage + V is applied to the other end. The emitter of transistor 38 is grounded. The external input detection signal 22 is taken out from the emitter of the transistor 38.

  When no input signal is applied to the external input terminals 11 and 12, no voltage is supplied to the bases of the transistors 34 and 38, and the transistors 34 and 38 are turned off. The voltage of the detection signals 21 and 22 increases by the voltage drop of the resistors 33 and 37 to which the voltage + V is applied. On the other hand, when an input signal is applied to the external input terminals 11 and 12, a voltage is supplied to the bases of the transistors 34 and 38, and the transistors 34 and 38 are turned on. The detection signals 21 and 22 drop in voltage to the ground level. Therefore, when the input signal is a voltage below a certain level (the voltage at which the transistor is turned off), the detection signal is high, and when the input signal exceeds a certain level (the voltage at which the transistor is turned on), the detection signal is low. It becomes.

  When both the detection signals from the input signal detection units 13 and 14 are low or high, the microcomputer 19 sends an instruction signal 23 for instructing surround ON to the surround circuit 15. The surround circuit 15 generates pseudo stereo signals (L + R, LR) and adds them to the left and right audio input signals to create a surround signal and drives the speakers 17 and 18 via the audio amplifier 16.

  If any of the detection signals 21 and 22 from the input signal detection units 13 and 14 is high, the microcomputer 19 sends an instruction signal 23 for instructing the surround circuit 15 to turn off the surround signal. The surround circuit 15 inputs the audio input signal to the audio amplifier 16 as it is without generating a pseudo stereo signal, and drives the speakers 17 and 18. At this time, an instruction signal 24 for performing OSD display of a warning warning for canceling the surround is sent to the display unit 20.

Now, FIG. 2 shows a surround processing procedure in this television receiver.
Although not shown in FIG. 1, the television receiver is instructed by a user to perform a processing operation by a remote controller. When the user presses the operation menu button using the remote controller, the operation menu is displayed on the television screen of the display unit 20, and the user selects an operation item using the remote controller to instruct the television receiver. Can be given.

  The microcomputer 19 confirms whether or not the external input is selected by the user operating the remote controller (step S1). If the external input is selected, it is confirmed whether “Surround” in the audio adjustment menu on the television screen as the display unit 20 is selected (step S2). If “surround” is selected, it is confirmed whether or not the signals from the input signal detectors 13 and 14 are only signals from either one (step S3). If the sound is input from the left and right 2ch, or if not input to both, the microcomputer 19 sends a surround ON instruction signal 23 to the surround circuit 15 to perform the surround processing (step S4).

  When only one of the signals from the input signal detectors 13 and 14 is input, the surround sound output is defective, and it is necessary to perform processing to prevent this.

First, the microcomputer 19 sends an OSD display instruction signal 23 to the display unit 20 to display the following contents (step S5).
・ "Connect the audio cable correctly to both audio input terminals (left / right)."
・ "If you want to input audio to only one channel, please select cancel."
・ "Yes or cancel"

  The microcomputer 19 confirms whether the user has selected “Yes” or “Cancel” using the remote controller (step S6). If the user selects “Yes”, the connection failure should have been resolved, so the process returns to step S 3 to check whether the voice input is made to both external input terminals 11 and 12.

When the user selects “Cancel”, there is a high possibility that the sound is output from the speaker poorly. Therefore, the microcomputer 19 sends the OSD display instruction signal 24 to the display unit 20 and gives the following warning.
・ "If audio is input to only one channel, normal surround effects may not be obtained and sound cracking may occur. Please enjoy with normal audio."
・ "Release surround"
・ "Yes" (select button)

  In this case, if surround output is performed as instructed by the user, a high load is applied to the speaker and the audio circuit, so the microcomputer 19 only performs processing for canceling surround. Note that the surround may be forcibly canceled suddenly, but in this case, the user may misunderstand it as a failure.

  The microcomputer 19 confirms whether or not the user has selected “Yes” (step S8), and when “Yes” is selected, sends a surround OFF instruction signal to the surround circuit 15 to perform normal audio processing. If the user does not select “Yes”, the process returns to step S7 to continue the warning display.

  In this way, when a stereo device is connected to a simple surround-equipped TV and surround is set, it is possible to prevent the volume difference between the left and right and the occurrence of excessive output from one speaker.

  Note that the present invention is not limited to this embodiment, and the caution warning is performed by characters. However, a picture or an icon may be displayed on the display unit 20, or voice may be displayed using the speakers 17 and 18. A warning warning may be given.

It is a block diagram which shows one Embodiment of the liquid crystal television receiver incorporating the surround apparatus which concerns on this invention. It is a flowchart which shows the procedure which detects a connection defect and prevents a voice defect. It is a block diagram of the conventional surround circuit.

Explanation of symbols

11, 12 External input terminals 13, 14 Input signal detection unit 15 Surround circuit 16 Audio amplifier 17, 18 Speaker 19 Microcomputer 20 Display unit 21, 22 External input detection signal 23 Surround instruction signal 31, 32, 33 Resistance 35, 36, 37 Resistor 34, 38 Transistor 50 Pseudo stereo circuit 51 Attenuation circuit 52, 53 Adder circuit 54, 55 Speaker L, R Left / right audio input signal LS, RS Pseudo stereo signal

Claims (3)

In a surround device that easily obtains a surround effect by obtaining the sum or difference of left and right audio input signals and adding to the input signal,
Input signal detecting means for detecting the presence or absence of the left and right audio input signals;
A surround means for generating a surround signal causing a surround effect;
A surround apparatus comprising: control means for turning off the surround means when the input signal detecting means detects that one of the signals is not inputted.   The surround device according to claim 1, wherein when the surround unit is turned off, the control unit performs a warning warning to the user using a warning notification unit.   3. The surround apparatus according to claim 2, wherein the control unit performs a warning by displaying a warning on the warning notification unit.

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