JPH087985B2 - Sound multiplex playback device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an acoustic multiple reproduction apparatus that simultaneously reproduces signals from different sound sources using a speaker and headphones.

The sound sources of an ordinary audio system are AM broadcast, FM broadcast, tape, and record, but one speaker system cannot reproduce these at the same time. FIG. 1 is a block diagram showing an on-vehicle audio system, and shows an example of a sound source system using a cassette deck 1, an AM tuner 2, and an FM tuner 3. The cassette deck 1 is controlled by a deck controller 4 using a microcomputer, and an audio signal obtained by the reproducing head HD
Add TAPE to one terminal of the function selector switch SW through the equalizer EQ and amplifier AMP. Tuners 2 and 3 are PLL
By the tuning method, the output of the phase locked loop (PLL) 5 is received by the high frequency stage and the frequency mixing section to tune. this
The microcomputer 6 called a tuner controller controls the frequency of the PLL 5. The audio signals AM and FM obtained by the tuners 2 and 3 are the remaining 2 of the switch SW.
It is led to the terminal.

Since the conventional changeover switch SW has three choices, mechanical type or electronic type, the audio signal is sent to the audio amplifier AF.
Only one of TAPE, AM, FM is supplied. SP is a speaker as a reproduction source. Other sources of reproduction include headphones, but the function switching shown in the figure merely reproduces the same signal from both the speaker and the headphones.
Reference numeral 7 is a key matrix for giving various instructions to the cassette deck or tuner, and the key operation information is coded by a microcomputer 8 called a key controller and relayed to the controllers 4 and 6. Reference numeral 9 is a remote controller having the same function as the key matrix 7, and the key operation information is also encoded by the key controller 8 in the same manner. Usually, the key matrix 7 is installed near the driver's seat,
The remote controller 9 is installed in the back seat.

The present invention enables a speaker and headphones to simultaneously reproduce desired audio signals in an audio system having at least three sound sources.

The sound multiplex reproduction apparatus of the present invention selects any one signal from the output signals of at least three sound sources by the first changeover switch and reproduces it by the speaker, and outputs any one signal from the output signals of the sound sources. Is connected in parallel to the first changeover switch and is selected by a second changeover switch which operates independently of the first changeover switch, and is reproduced by headphones. This will be described in detail below with reference to the illustrated embodiment.

FIG. 2 is an embodiment of a sound invention in which a speaker SP is used as the main acoustic transducer and a headphone HP is used as the sub acoustic transducer, and shows the configuration after the switch unit for receiving the audio signals AM, FM and TAPE of FIG. It is a thing. AF ₁ is a speaker amplifier and AF ₂ is a headphone amplifier, which is provided exclusively. Also the first
The PLL5 in the figure has two systems, and by dynamically driving these, AM and FM can be received simultaneously. SW _{11 to} SW ₃₁
Is an analog switch that selects which _one of the audio signals AM, FM, TAPE is led to the amplifier AF ₁ , and SW _{12 to} SW ₃₂ are analog switches that also select which one of them is led to the amplifier AF ₂ . . These switches are controlled by the output of the latch RT which receives the key code directly from the key controller 8 in FIG. 1 or via another controller.

In the present apparatus, designation of simultaneously generating any two of audio signals AM, FM and TAPE is performed by the key matrix 7 and the remote controller 9 shown in FIG. Hereinafter, it is assumed that the remote controller 9 is used to select a sound source for the headphone HP and the key matrix 7 is used to select a sound source for the speaker SP. However, it is also possible to control both the speaker SP ₁ and the headphones HP by an instruction from the remote controller 9. If such a function can be specified, for example, from the speaker SP to the passenger compartment
When FM broadcasting is playing (switch SW ₂₁ on), operate the remote controller 9 from the rear seat to switch SW ₁₂
Also, if you turn on SW ₃₂ , you can listen to AM broadcast or TAPE performance with headphones HP.

FIG. 3 shows a specific example of the changeover switch section, where RT ₁ and RT ₂ are the second
The latch RT in the figure is divided into a speaker and a headphone. SW _{1 to} SW ₃ are analog switches integrated into an IC, i _{1 to} i ₄ are input terminals, ₁ to ₄ are output terminals, and c _{1 to} c ₄
Is the control terminal. The analog switch SW ₁ is for AM and corresponds to the switches SW ₁₁ and SW ₁₂ in FIG. In this example, assuming that the reproduction source is for stereo, L and R signal paths are provided, and i ₁ , i ₂ , ₁ and ₂ are connected to the switch SW ₁₁ , and
i ₃ , i ₄ , ₃ , ₄ correspond to the switch SW ₁₂ . The same applies to the analog switches SW ₂ and SW ₃ , and the analog switch SW ₂ for FM corresponds to the switches SW ₂₁ and SW ₂₂ in FIG.
The analog switch SW ₃ for PE is the switch SW ₃₁ , SW _{32 in} the figure.
Equivalent to. Latch RT ₁ is a switch SW _{1 to} SW with outputs F _{1 to} F _3.
Select one of the ₃ speaker side (amplifier AF ₁ side). The latch RT ₂ selects the headphone side of the switch SW ₁ to SW ₃ (the amplifier AF ₂ side) at the output S ₁ to S _3. The key codes D _{A to} D _D for these latches are fetched at timings L ₁ and L ₂ . The table below shows the relationship between key codes and functions.

As is clear from the above table, the definitions of codes D _{A to} D _D are the same for both. The code D _{A to} D _D is switched by the controller in the preceding stage for the speaker and the headphone at the timing shown in FIG. 4 (of course the content depends on the key matrix and the remote controller), and it is latched at different timings L ₁ and L _2. Speaker SP by loading into ₁ and RT ₂
And headphones HP can play different signals. In the example of the figure, the code of AM designated by the key matrix 7 is latched RT ₁
And specified by the remote controller 9.
It shows how the FM code is loaded into the latch RT ₂ .
The undefined code can be used, for example, to specify the player.

As described above, according to the present invention, even when the sound source has three or more sound sources, the interior of the automobile can be acoustically multiplexed like an airplane, and the same music as that output from the speaker can be obtained. Of course, it is possible to listen to different things through the headphones, so that desired audio signals can be simultaneously reproduced by the speaker and the headphones. In addition, even if the sound source reproduced by the speaker (or headphones) is switched, the headphone (or speaker) side is not affected at all.

[Brief description of drawings]

FIG. 1 is a block diagram showing a multi-source audio system, and FIG. 2 is a block diagram showing essential parts of an embodiment of the present invention.
FIG. 3 and FIG. 4 are a block diagram and a time chart showing the specific example. In the figure, 1 to 3 are sound sources, SP is a speaker, HP is headphones,
SW _{1 to} SW ₃ and SW _{11 to} SW ₃₂ are changeover switches.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Shou 50-68704 (JP, U) Seki 51-87401 (JP, U) Seki 56-77092 (JP, U)

Claims (1)

[Claims] 1. An arbitrary one signal from the output signals of at least three or more sound sources is selected by a first changeover switch and reproduced by a speaker, and an arbitrary one signal is outputted from the output signals of the sound sources as the first signal. 2. A sound multiplex reproducing apparatus characterized by being selected by a second change-over switch which is connected in parallel to the change-over switch and which operates independently of the first change-over switch to reproduce by headphones.