JP3317356B2 - Television receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver.

[0002]

2. Description of the Related Art In recent television broadcasting, audio multiplex broadcasting is performed. In response to this, a television receiver discriminates between a monaural mode and a stereo mode, and outputs an audio signal corresponding to each mode. The demodulation process is performed so that sound according to each mode can be output from the speaker of the television receiver. Incidentally, the optimum sound field of the audio signal output from the television receiver differs depending on the type of the audio signal to be broadcast.
For example, in a program such as news, the voice of an announcer is the main sound source, so that the sound image is preferably localized at the center of the screen. Furthermore, in a music program or the like, it is preferable that the so-called super wide spread more horizontally than in a drama program. Therefore, the left and right speakers are made rotatable about a vertical axis, and the viewer adjusts the angles of the speakers manually or by operating a remote control device according to the type of the audio signal to be broadcast, to obtain an optimal sound field. The configuration provided is already known.

[0003]

However, in the above conventional example, since the angle adjustment of the speaker is performed by manual operation or operation of the remote control device, it is troublesome and inconvenient.

An object of the present invention is to provide a television receiver which solves the above problems.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is characterized in that a pair of left and right first speakers arranged to face sideways and a pair of left and right first speakers arranged to face forward. A pair of left and right second speakers, first attenuating means for attenuating the level of an audio signal input to the first speaker,
Second attenuating means for attenuating the level of the audio signal input to the speaker, mode determining means for determining whether the received audio signal is in the stereo mode or monaural mode, and frequency component determining means for determining the frequency component of the received audio signal And the first and second speakers based on the determination result by the mode determination unit and the determination result by the frequency component determination unit so that the volume levels of the first and second speakers become a predetermined combination.
Control means for controlling the amount of attenuation of the attenuation means. The first damping means and the second damping means are linked to each other, and the damping amount of the first damping means is within a range from the maximum value to the minimum value of each of the first and second damping means. Changes in the direction of decreasing from the maximum value, the amount of attenuation of the second damping means is changed in the direction of increasing from the minimum value in conjunction with this, and the amount of attenuation of the first damping means increases from the minimum value. When changing in the direction, there may be provided such an interlocking means for changing the amount of attenuation of the second damping means in a direction decreasing from the maximum value in conjunction therewith.

[0006]

According to the present invention, the mode determining means determines whether the mode of the received audio signal is the stereo mode or the monaural mode. The frequency component of the received audio signal is determined by the frequency component determining means. Then, based on the results of the discrimination by the two discriminating means, the control means controls the amount of attenuation of the first and second damping means so that the volume levels of the first and second speakers become a predetermined combination. Thereby, the volume level radiated to the side from the first speaker and the volume level radiated forward from the second speaker are automatically changed, and a desired combination of volume levels is achieved, An optimal sound field according to the type of the received audio signal can be provided.

[0007]

FIG. 1 is a horizontal sectional view showing the internal structure of an embodiment of a television receiver according to the present invention. In the main body 2 of the television receiver 1, a pair of left and right first speakers 4L and 4R is disposed on both sides of the cathode ray tube 3 so as to face the side, and a pair of left and right second speakers 5L and 5R are provided. , Facing the front. These first speakers 4L, 4R
The input level of the audio signal to the second speaker 5L, 5R is automatically adjusted according to the type of the received audio signal.

In this embodiment, as will be described in detail later, adjustment is made in accordance with three types of audio signals, such as news announcements, dramas, and music programs. For example,
In the case of an announcement such as news, the first speaker 4L,
The input level of the audio signal to the 4R is minimum (that is, the audio signal is attenuated to almost 0 level) and the second
The input level of the audio signal to the speakers 5L and 5R is set to the maximum (that is, the audio signal is hardly attenuated). In the case of a drama or the like, the input levels of the audio signals to the first speakers 4L and 4R and the second speakers 5L and 5R are both intermediate (that is, the audio signals are attenuated to １ ／). . Further, the music program includes the first speaker 4L,
The input level of the audio signal to the 4R is maximum (that is, the audio signal is hardly attenuated) and the second speaker 5
The input level of the audio signal to L and 5R is minimized (that is, the audio signal is attenuated to almost zero level).

FIG. 2 is a block diagram of an audio circuit provided in one embodiment of the television receiver according to the present invention.
Although not shown, the video signal processing circuit of the television receiver 1 has a known configuration.
The intermediate frequency signal amplified by the video intermediate frequency amplification circuit (not shown) is converted by the audio detection circuit 10 into a video carrier (58.75 MHz) and an audio carrier (54.25 MH).
z) and 4.5M which is the frequency difference between the two carrier waves.
The frequency is converted to an audio intermediate frequency signal of 1 Hz, amplified by an audio intermediate frequency amplifier circuit 11, supplied to an audio FM detection circuit 12 and subjected to FM detection. In addition to the main audio signal, the detected signal is multiplexed with a carrier sub-audio signal obtained by frequency-modulating a sub-carrier with a sub-audio signal and a carrier multiplex control signal obtained by amplitude-modulating a sub-carrier with a control signal.

The output from the audio FM detection circuit 12 is reduced in high frequency by a de-emphasis circuit 13 and flattened, and an unnecessary component (multiplex signal component) of 0 to 15 KHz or more is removed by a low-pass filter 14. The main audio signal is provided to the audio matrix circuit 15. The output from the audio FM detection circuit 12 is applied to a band-pass filter 16 to extract a carrier sub-audio signal. Then, this carrier sub-audio signal passes through the amplitude limiting circuit 17 and
The FM detection is performed by the M detection circuit 18 and the de-emphasis circuit 1
9. Passing through the low-pass filter 20 sequentially, 0 to 15K
Unnecessary components (multiple signal components) above Hz are removed,
The sub audio signal is supplied to the audio matrix circuit 15.

The band-pass filter 16 has 5
A trap is provided for removing the 5.125 KHz carrier multiplex control signal, thereby extracting the carrier multiplex control signal. And this carrier multiplex control signal is
The signal is detected by the multiplex control AM detection circuit 22 and the amplitude
3, and is subjected to FM detection by a multiplex control FM detection circuit 24 as a mode determination means. Thereby, the frequency of each control signal in the two-audio mode and the stereo mode (922.5 Hz in the two-audio mode, 9 in the stereo mode)
82.5 Hz) and a DC voltage corresponding to a monaural frequency (set to 952.5 Hz in the middle). That is, the detection output voltage is, for example, 1 V in the two sound mode, 4 V in the monaural mode, and 8 V in the stereo mode, and different output voltages are obtained depending on each sound multiplex mode. Therefore, the output from the multiplex control FM detection circuit 24 allows the current received audio signal to be
It is possible to know which of the two audio modes, the monaural mode, and the stereo mode.

The detection output from the multiplex control FM detection circuit 24 is supplied to a changeover switch control circuit 25 and an attenuator control unit 26, respectively. The changeover switch control circuit 25 changes the switching mode of each changeover switch of the audio matrix circuit 15 described later according to each mode. In the figure, P1 is a control terminal for forced monaural mode, and P2 is a control terminal for selecting each mode of two sounds (main sound, sub sound, main sound + sub sound). That is, in the two-voice mode, the main voice mode is selected when the voltage value of the control terminal P2 is set to, for example, 0V, the sub-voice mode is selected when the voltage is set to 5V, and the main voice + sub-voice mode is selected when the voltage value is 2.5V. Further, when the voltage value of the control terminal P1 is set to, for example, 4.5 V in the stereo mode, the monaural mode is forcibly set.

The audio matrix circuit 15 includes main / sub switching switches S1 and S2 for switching between main audio and sub audio.
A stereo matrix circuit 28 and four switches S3 for switching related to the stereo matrix circuit 28
1, S32, S33, and S34. Then, the changeover switch control circuit 25 controls each switch S
The switching modes of S1, S2, S31, S32, S33, and S34 are controlled as shown in Table 1.

[0014]

[Table 1] In the figure, a and b are switches S1, S2, S31, S
32, S33, and S34 indicate individual contacts.
A main audio signal is supplied to the individual contacts a of S1 and S2, and a sub audio signal is supplied to the individual contacts b of the switches S1 and S2.

The output from the switch S32 is supplied to a low frequency amplifier circuit 30L and a mixing circuit 35.
A variable resistor 7L as first attenuating means is interposed between the low-frequency amplifier circuit 30L and the first left speaker 4L, and between the low-frequency amplifier circuit 30L and the second left speaker 5L. Has a variable resistor 8 as a second damping means.
L is interposed. Similarly, the output from the switch S34 is output to the low frequency amplifier circuit 30R and the mixing circuit 3R.
5 given. This low-frequency amplifier circuit 30R and the right first
A variable resistor 7R as first attenuating means is interposed between the speaker 4R and the low-frequency amplifier 30R.
A variable resistor 8R as a second damping means is interposed between the second resistor 5R and the right second speaker 5R. Variable resistor 7L
And the variable resistor 8L, when the resistance value of the variable resistor 7L is the maximum, the resistance value of the variable resistor 8L is the minimum, and when the resistance value of the variable resistor 7L increases, the variable resistor When the resistance value of the variable resistor 8L decreases and the resistance value of the variable resistor 7L decreases, the resistance value of the variable resistor 8L increases correspondingly, thereby forming a so-called dual variable resistor 9L. The variable resistor 7R and the variable resistor 8R also constitute a double variable resistor 9R that performs the same operation as the double variable resistor 9L. The resistance values of these double variable resistors 9L and 9R are made variable by a control signal from the attenuator control unit 26.

Referring to Table 1, the flow of audio signals during monaural broadcasting, stereo broadcasting, and dual audio broadcasting will be described. In monaural broadcasting, the main audio signal does not pass through the stereo matrix circuit 28, As the left and right audio signals, low frequency amplifier circuits 30L and 30R, variable resistor 7
L, 8L; output from left and right first and second speakers 4L, 5L; 4R, 5R via 7R, 8R. During stereo broadcasting, the main sound is a left / right sum signal (R +
L), a left and right audio difference signal (RL) is sent to the sub audio, passed through the stereo matrix circuit 28, and
Is output from the first and second left and right speakers 4L and 5L via the low frequency amplifier circuit 30L and the variable resistors 7L and 8L, and the right audio signal R is output from the low frequency amplifier circuit 30R and the variable resistors 7R and 8R. Through the first and second speakers 4 on the right side
Output from R and 5R.

In the case of two-sound broadcasting, for example, when the main sound mode is selected, the main sound signal is divided into left and right first and second speakers 4L and 5 according to the voltage value applied to the control terminal P2.
L; 4R, 5R, when the sub audio mode is selected, the sub audio signals are the left and right first and second speakers 4L, 5L;
When the main sound + sub sound mode is selected from 5R, the main sound is outputted from the first and second speakers 4L and 5L on the left side, and the sub sound is outputted from the first and second speakers 4R and 5R on the right side. When a 4.5 V voltage for forced monaural mode selection is externally applied to the control terminal P1 during stereo broadcasting, the main audio signal is transmitted to the left and right first and second speakers 4L as in monaural broadcasting. , 5L; 4R, 5R.

On the output side of the audio matrix circuit 15, there is provided a mixing circuit 35 for mixing the main audio signal and the sub audio signal, and the output from the mixing circuit 35 determines the frequency component of the audio signal. The signal is supplied to the frequency component determination circuit 36. The frequency component discriminating circuit 36 includes, for example, a low-pass filter 37 that blocks 200 Hz or more.
And a high-pass filter 39 for blocking, for example, 5000 Hz or less. The mixed audio signals from the mixing circuit 35 are respectively applied to these filters 37 to 39. Given individually. The outputs of the filters 37 to 39 are provided to the attenuator control unit 26. The attenuator control unit 26 controls the double variable resistors 9L and 9R based on the determination of the stereo / monaural mode based on the output from the multiplex control FM detection circuit 24 and the combination of the presence or absence of the output from each of the filters 37 to 39. Output the control signal,
The input level of the audio signal to each of the first and second speakers 4L, 5L; 4R, 5R is adjusted.

Hereinafter, the automatic volume level adjusting operation of the first and second speakers 4L, 5L; 4R, 5R according to the type of the audio signal in the television receiver 1 having the above configuration will be described. When the detection output from the multiplex control FM detection circuit 24 is given to the changeover switch control circuit 25, the changeover switch control circuit 25 switches each of the switches S1 and S1 according to the voltage level of the detection output, that is, the mode of the received audio signal.
The switching of S2, S31, S32, S33, S34 is switched as shown in Table 1 above. As a result, the audio signal corresponding to each mode is transmitted to the left and right first and second speakers 4.
L, 5L; output from 4R, 5R.

At the same time, the audio signal from the mixing circuit 35 is supplied to the attenuator control unit 26 via the filters 37 to 39, and the detection output from the multiplex control FM detection circuit 24 is also supplied to the attenuator control unit. 26. As a result, the attenuator control unit 26 determines the stereo / monaural mode shown in Table 2 stored in the storage unit in the attenuator control unit 26 and combines the data indicating the presence or absence of the output from each of the filters 37 to 39. Based on the above, the double variable resistor 9L is set such that the combination of the input level of the audio signal to the first speakers 4L and 4R and the input level of the audio signal to the second speakers 5L and 5R becomes the combination shown in Table 2. , 9R. Thereby, the volume level radiated to the side from the first speakers 4L and 4R and the volume level radiated to the front from the second speakers 5L and 5R change, respectively.
A desired combination of volume levels is achieved, and an optimal sound field according to the type of the received audio signal can be provided.

[0021]

[Table 2] More specifically, with reference to Table 2, when the audio signal is a news program announcement, the multiplex control F
The detection mode from the M detection circuit 24 determines that the mode is the monaural mode, and the output of the low-pass filter 37 is “0”.
Since the output of the band-pass filter 38 is “1” and the output of the high-pass filter 39 is “0”, the attenuator control unit 26
By controlling the resistance values of the first speakers 4L, 4R
The input level to the second speakers 5L and 5R is minimized (that is, the audio signal is attenuated to almost zero level).
Is adjusted so that the input level to the signal becomes maximum (that is, a state in which the sound signal is hardly attenuated). Thus, the sound image localization direction can be set to the front center.

When the audio signal is a drama or the like, the multiplex control FM
The detection mode from the detection circuit 24 determines that the mode is the stereo mode, and the output of the low-pass filter 37 is “0”.
Since the output of the band-pass filter 38 is “1” and the output of the high-pass filter 39 is “0”, the attenuator control unit 26
By controlling the resistance values of the first speakers 4L, 4R
And the input levels to the second speakers 5L and 5R are both adjusted to be intermediate (that is, the audio signal is attenuated to １ ／). Thereby, the sound image localization direction can be widened.

When the audio signal is a music program or the like, the multiplex control F
The detection output from the M detection circuit 24 determines that the output is stereo, and the output of the low-pass filter 37 is “1”, the output of the band-pass filter 38 is “1”, and the output of the high-pass filter 39 is “1”. Therefore, the attenuator control unit 26 includes two variable resistors 9L and 9
By controlling the resistance value of R, the input level to the first speakers 4L and 4R is maximized (that is, the sound signal is hardly attenuated), and the input level to the second speakers 5L and 5R is minimized (that is, The adjustment is performed so that the audio signal is attenuated to almost zero level). Thereby, the sound image localization direction can be made super wide. In the two-voice mode, the first speaker 4 is connected in the same manner as in the monaural mode.
L, 4R, and the second speaker 5
Adjustments are made so that the input levels to L and 5R are maximized.

Such an attenuator control
The control of the unit 26 to the dual variable resistors 9L and 9R is as follows.
The first speaker 4L, 4R and the second speaker 5 are switched according to the content of the program even if the channel is switched or the program is shifted to the next program.
The volume levels of L and 5R are automatically adjusted to a predetermined combination, so that an optimal sound field can always be provided to the viewer. In the above embodiment, the first speakers 4L, 4L
Although there are three combinations of R and the volume levels of the second speakers 5L and 5R, the present invention is not limited to this, and other combinations of a plurality of types may be performed. In the above-described embodiment, the first speakers 4L and 4R and the second speakers 5L and 5R are built in the television receiver main body 2, but as shown in FIG.
The speakers 4L, 5L and 4R, 5R may be provided on the television receiver body 2, respectively.

[0025]

As described above, according to the present invention, the volume level radiated to the side from the first speaker and the volume level radiated to the front from the second speaker are automatically adjusted according to the type of the audio signal. Volume level can be changed individually,
An optimal sound field according to the type of the received audio signal can be provided. Therefore, it is easier to use than the conventional example,
A television receiver with improved operability can be realized.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing the internal structure of an embodiment of a television receiver according to the present invention.

FIG. 2 is a block diagram of an audio circuit provided in one embodiment of the television receiver according to the present invention.

FIG. 3 is a simplified horizontal sectional view showing the internal structure of another embodiment of the television receiver according to the present invention.

[Sign]

DESCRIPTION OF SYMBOLS 1 ... Television receiver, 2 ... Television receiver main body, 4L, 4R ... 1st speaker, 5L, 5R ... 2nd speaker, 7L, 8L, 7R, 8R ... Variable resistor, 9L, 9
R: double variable resistor, 15: voice matrix circuit, 2
4: Multiple control FM detection circuit, 25: Changeover switch control circuit, 26: Attenuator control unit,
28: stereo matrix circuit, 35: mixing circuit, 36: frequency component determination circuit, S1, S2, S31,
S32, S33, 34 ... switches.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 5/50-5/63 H04H 5/00-5/00 303 H04S 1/00-7/00

Claims (2)

(57) [Claims] 1. A pair of left and right first speakers disposed facing the side, a pair of left and right second speakers disposed facing the front, and a level of an audio signal input to the first speaker. First attenuating means for attenuating, second attenuating means for attenuating the level of the audio signal input to the second speaker, mode determining means for determining whether the received audio signal is a stereo mode or a monaural mode, and a received audio signal Based on the frequency component discriminating means for discriminating the frequency components of the first and second speakers, based on the discrimination result by the mode discriminating means and the discrimination result by the frequency component discriminating means. And a control means for controlling the amount of attenuation of the first and second attenuation means. 2. A means for linking a first damping means and a second damping means, wherein the first damping means is provided within a range from a maximum value to a minimum value of each of the first and second damping means. When the amount of attenuation changes in a direction decreasing from the maximum value, the amount of attenuation of the second attenuation means is changed in a direction increasing from the minimum value in conjunction with this.
When the amount of attenuation of the first attenuating means changes in a direction increasing from the minimum value, the amount of attenuation of the second attenuating means changes in a direction decreasing from the maximum value. The television receiver according to claim 1, further comprising: