JPH0328640Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a mixing circuit, and in particular, when the difference in volume between the L-channel side and the R-channel side exceeds a predetermined value, in other words, one channel The present invention relates to a mixing circuit that combines audio signals of both channels when the volume of the channel is reduced to a predetermined level or less, and outputs audio based on the synthesized audio signal from the speaker of the channel whose volume is not reduced.

<Prior art> Audio equipment is equipped with a balance volume that adjusts the balance between the volumes output from the left and right speakers.If such a balance volume is used, it is possible to listen to music at a position that is symmetrically centered with respect to both speakers. You can enjoy stereo listening even when no one is around.

In addition, even if only one person in the rear seat of the vehicle wants to listen to music output from the in-vehicle audio equipment, the balance volume can be adjusted so that the sound is output only from the speaker on the listener's side. As a result, you can enjoy music etc. without bothering others in the rear seat.

<Problem that the invention is trying to solve> By the way, conventionally, when the volume of one channel is reduced using a balance volume, only the audio based on the audio signal of the other channel is output from the speaker of the other channel. Ta. For this reason, in the past, there was a problem in that when the volume on one channel was reduced, good audio was not output.

From the above, the purpose of the present invention is that even if the volume ratio of both the left and right channels exceeds a predetermined value using the balance volume, or in other words, even if the volume of one channel is reduced to a predetermined level or less, the balance volume will not be heard from the speakers on the other channel. An object of the present invention is to provide a mixing circuit capable of outputting good audio based on synthesized audio signals of both left and right channels.

<Means for Solving the Problems> The mixing circuit according to the present invention includes a switch that operates when the volume ratio of the L-channel side and the R-channel side exceeds a predetermined value, and a volume control circuit that operates through the switch. It is configured to include a synthesizing section that synthesizes the audio signal of the narrowed channel with the audio signal of the other channel.

<Function> A switch that operates when the volume ratio of the L-channel side and the R-channel side reaches a predetermined value or more, and the audio signal of the channel whose volume has been reduced through the switch is changed to the audio signal of the other channel. A mixing circuit is configured with a synthesis section that synthesizes the signals.
The switch is configured to operate, for example, when the knob of the balance volume is rotated by a predetermined angle or more from the balance position. As a result, when the volume of one channel (for example, L-channel) is reduced using the balance volume, good sound based on the synthesized audio signals of both left and right channels is output from the speaker of the other channel (R-channel). Output.

<Embodiment> FIG. 1 is an explanatory diagram of a mixing circuit according to the present invention. In the figure, 11L and 11R are the left channel and right channel preamplifiers, respectively, and 12L,
Similarly, 12R is the main amplifier for both left and right channels, 13L and 13R are speakers for both left and right channels, 14L and 14R are volumes for both left and right channels, 15 is a balance volume that adjusts the volume ratio of the left channel and right channel, and 16 is a balance volume. The mixing circuit according to the present invention has a switch 16a and a combining section 16b. In addition, C1-C2 are capacitors for DC cut, and R1-R4 are resistors.

The switch 16a of the mixing circuit 16 is configured to operate when the knob of the balance volume 15, which adjusts the volume ratio between the L-channel side and the R-channel side, is rotated by a predetermined angle or more from the balance position to one channel side. has been done. That is, when the volume ratio between the L-channel side and the R-channel side exceeds a predetermined value, the switch 16a
Alternatively, it is designed to operate when the volume of one channel is reduced below a predetermined level.

The synthesizing section 16a has a function of synthesizing the audio signal of the channel whose volume has been reduced through the switch with the audio signal of the other channel when the switch 16a is operated. Note that the degree of one volume to be synthesized with the audio of the other channel (the channel whose volume is not reduced) depends on the values of the resistors r1 to r4.

FIGS. 2 and 3 are explanatory diagrams of the switch, and are examples in which the switch operates depending on the rotation angle of the knob of the balance volume 15. 3A is a plan view of the conductor pattern portion of the switch, and FIG. 3B is a bottom view of the slider piece.

In FIG. 2, 15 is a balance volume, which includes a knob 15a, a shaft 15b, and a main body 15.
c, and by rotating the knob 15a, in other words, the shaft 15b, the main body 15
c The resistance value of the built-in variable resistance section changes. 16a
is a switch, and as shown in Figure 3, the slider piece SL made of insulating material and the conductive pattern
It is composed of PN. The slider piece SL is shaped like a hat, for example, and a shaft 15b is attached to the hat PS, and a conductive brush BL is formed on the outer periphery of the flange BR. And this slider SL is the knob 1 of the balance volume 15.
When 5a is rotated, they rotate together, and the brush BL slides on the conductive pattern of the conductive pattern portion PN.

The conductor pattern part PN is connected to an insulating substrate BD,
First and second conductive patterns P1 and P2 formed on the substrate, electrodes PL1 and PL2 connected to one end of each conductive pattern P1 and P2, and terminals T1 and T
It has 2.

The brushes BL of the slider piece SL are conductive patterns P1, P
It is attached to the conductor pattern portion PN so as to slide on the conductor pattern portion PN. In addition, balance volume 1
5, in the balance position where the volume of both left and right channels is balanced, the brush BL is set to the third
It is located at the dotted line position in Figure A. When the knob 15a is rotated clockwise or counterclockwise from this balanced position by a predetermined angle A or more, the conductive pattern P
1 and conductive pattern P2, resulting in a switch.

From the above, in order to make the volume ratio of both left and right channels equal to or higher than a predetermined value in FIG.
When the switch 16a is rotated by a predetermined angle A or more from the balance position, the switch 16a is closed. For example, when the volume on the L-channel side is reduced to a predetermined level or less, the L-channel audio signal is synthesized with the R-channel audio signal via the switch 16a and the synthesizer 16b, and is output from the R-channel speaker 13R. Ru. Similarly, when the volume on the R-channel side is reduced to a predetermined level or less, the audio signal of the R-channel is converted to the L-channel via the switch 16a and the synthesis section 16b.
It is synthesized with the audio signal of the channel and output from the L-channel speaker 13L.

<Effect of the invention> According to the invention as described above, the L-channel side and the R-
A mixing circuit consists of a switch that operates when the volume ratio on the channel side exceeds a predetermined value, and a synthesis section that synthesizes the audio signal of the channel whose volume has been reduced through the switch with the audio signal of the other channel. At the same time, when the volume of one channel is reduced below a predetermined level, the synthesized sound of both channels is output from the speaker of the other channel. Therefore, it is possible to output good sound, and therefore it can be used, for example, in a vehicle interior. When only one person in the rear seat of a car listens to music output from one channel speaker, the user can enjoy high-quality music.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a mixing circuit according to the present invention, and FIGS. 2 and 3 are explanatory diagrams of switches used in the mixing circuit. 11L, 11R...Preamplifier, 12L, 12
R...Main amplifier, 13L, 13R...Speaker, 15...Balance volume, 15a...
Knob, 16...Mixing circuit, 16a...Switch, 16b...Synthesizing section.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A balance volume that adjusts the volume ratio between the L-channel side and the R-channel side, and when the volume ratio between the L-channel side and the R-channel side exceeds a predetermined value. and a synthesis section that synthesizes the audio signal of the channel whose volume has been reduced through the switch with the audio signal of the other channel, and the synthesized audio of both channels is output from the speaker of the other channel. A mixing circuit characterized by output. (2) The utility model registration claim 1 is characterized in that the switch is operated by rotating the knob of the balance volume from the balance position toward one channel by a predetermined angle or more.
The mixing circuit described in (1).