JPH0222936A - On-vehicle sound system - Google Patents

Abstract

PURPOSE:To reduce the required number of cables by sharing a signal line by a low frequency transmission path and high frequency transmission path without generating the crosstalk of a signal. CONSTITUTION:An antenna ANT is connected to the signal line of a transmission path 2a via a capacitor C1, and also, the acoustic signal output line 1a of an acoustic equipment main body 1 is connected, and furthermore, the inductance L1 of a speaker SPL is connected to the signal line of a transmission path 2a via a coil CH for blocking high frequency. In other words, the transmission path 2a is shared by conventional high frequency transmission path and low frequency transmission path. At this time, the crosstalk of a high frequency signal or its mixing signal from the antenna can be blocked by the coil CH for blocking high frequency. In such a way, it is possible to reduce the required number of cables.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle-mounted audio system including an antenna, an audio equipment main body, and audio signal output means.

[Summary of the Invention] In a vehicle-mounted audio system, a signal line connecting an antenna or a mixing means for mixing a plurality of antenna inputs and an audio equipment main body includes an audio signal output line of the audio equipment main body,
and by connecting an acoustic signal output means through a high frequency rejection filter.

By sharing high and low frequency signal transmission lines, it is possible to reduce costs, reduce installation man-hours, and reduce vehicle noise.

[Prior Art] A conventional in-vehicle sound system was configured as shown in FIG. In Figure 7, 1 is the in-vehicle receiver body, 2 and 3 are high frequency transmission lines, 4.5 and 6.7 are low frequency transmission lines, and ANT.
l is the front antenna, ANT2 is the rear antenna,
5pFL is the front left speaker, 5PPR is the front right speaker, 5pRL is the rear left speaker, 5pRR
represents the rear right speaker. The high frequency transmission lines 2, 3 are formed of coaxial cables, and the low frequency transmission lines 4, 5, 6.7 are formed of low frequency parallel two-wire cables. ANT2 is a rear glass antenna or rear ball antenna provided at the rear of the vehicle, and low frequency transmission lines 4 and 5 are also connected to speakers S PRL e provided at the rear of the vehicle living space.
This is for driving the S P RR.

Furthermore, FIG. 8 shows the simplest conventional system for an on-vehicle receiver. In the same figure, the antenna ANT, the on-vehicle receiver main body 1, and the speaker SP are each connected to a high-frequency transmission line 2. They are coupled via a low frequency transmission line 1. Car antenna ANT
The information received is converted into an audio signal by the in-vehicle receiver 1, which drives the speaker SP.

[Problems to be Solved by the Invention] The transmission line shown in FIG. 7 not only generally requires a line length of 4 m or more from the main body 1.

Connection between the ANT 2 and the high frequency transmission line 2 1 Connection between the main body 1 and the high frequency transmission line 2 is required. This also applies between the low frequency transmission line 4, the speaker spR, and the main body 1°, and between the low frequency transmission line 5, the speaker 5PRR, and the main body 1.

Even in the simplest system shown in FIG. 8, the antenna ANT and the high frequency transmission line 2 are connected, the high frequency transmission line 2 and the in-vehicle receiver 1 are connected, and the speaker SP is connected to the low frequency transmission line 4, the in-vehicle receiver 1 and the in-vehicle receiver 1 are connected. Connection of the frequency transmission line 4 is required.

Furthermore, when installing these transmission lines in a vehicle, the harness itself and the inter-harness processing are required.

Processing is also required for installation on the vehicle, and the overall cost increase cannot be ignored.

[Object of the Invention] The object of the present invention is to reduce the cost of installation and processing, reduce the number of cables even by just one, reduce material costs, and facilitate the processing of inter-vehicle noise. The purpose is to provide a sound system.

[Means for Solving the Problems] In order to achieve the above objects, the first in-vehicle audio system according to the present invention has the following features: and an acoustic signal output means connected via a high frequency blocking filter to the signal line connecting the antenna and the main body of the audio equipment.

A second in-vehicle audio system according to the present invention includes means for mixing a plurality of antenna inputs, and an audio signal output line of the audio equipment main body connected to a signal line connecting the mixing means and the audio equipment main body. The gist of the present invention is to include acoustic signal output means connected via a high frequency blocking filter to a signal line connecting the mixing means and the main body of the audio equipment.

[Function] The number of required cables is reduced by sharing one line for the low frequency transmission line and the high frequency transmission line. that time,
The high frequency blocking filter prevents the high frequency signal from the antenna or its mixed signal from going around to the acoustic signal output means.

[Examples] The present invention will be explained in more detail below using Examples with reference to the drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a conceptual diagram showing the configuration of a first in-vehicle audio system according to the present invention. In FIG. 1, the reference numbers common to FIG. 7 are the same as those in FIG. 7, or represent parts corresponding thereto. .

The transmission line 2a shown in FIG. 1 shares the high frequency transmission line 2 and the low frequency transmission line 4 of the conventional example, and may use, for example, a signal line such as a single high frequency coaxial cable. A more detailed explanation is as shown in FIG.

In Figure 2, 8 is a high frequency input circuit, and 9 is a tuning circuit.

IF amplifier, detector, multiplexer, etc., 10 is an audio adjustment circuit, 11 is a power amplifier, C8 is a capacitor for low frequency blocking, C□ is a capacitor for high frequency passing, C, is a capacitor for high frequency passing, CH is for high frequency blocking. The coil Ll represents the inductance of the speaker SPL.

The antenna ANT is connected to the capacitor C on the signal line of the transmission path 2a.
1, and is also connected to the audio signal output line 1a of the audio equipment main body 1. Further, an inductance L of the speaker SP is connected to the signal line of the transmission line 2a via a high frequency blocking coil CH.

Note that the installation location of the antenna ANT and the speaker SPL is, of course, not limited to the rear side of the vehicle surface.

The operation of the above embodiment will be explained below.

After passing through the capacitor C1, the high frequency signal from the ANT is blocked by the coil CH from reaching the speaker SP, so it reaches the high frequency input circuit 8 of the main body 1. Further, the audio signal can drive the speaker SPL from the power amplifier 11 via the transmission path 2a and the coil CH. Of course, the power on the transmission line 2a can be transmitted without any problem in the case of a normal car audio system. When transmitting these signals, capacitors C, , C, are used to bypass high frequency signals, and capacitor C2 is grounded on the high frequency input circuit side. In addition, the coil CH is for high frequency blocking, and can be used independently of the inductance L□ or L□
If this coil CH is not provided, the high frequency signal is likely to be attenuated as shown in FIGS. 3 to 5, so care must be taken. The figures show an example of an 8Ω/4W speaker.

According to the above embodiment, the signal transmission path between the antenna, the speaker, and the main body of the audio equipment is shared for high and low frequencies, so the man-hours and material costs for installing signal lines in the vehicle are reduced, and the number of signal lines is also reduced. Since the number of noise sources is also reduced, the contamination of vehicle noise is reduced.

FIG. 6(a) shows a second in-vehicle audio system according to the present invention, which is particularly intended to improve the conventional example shown in FIG.

In FIG. 6(a), 13 represents a mixing circuit, 14 represents a high/low frequency shared signal transmission line according to the present invention, ANT3 represents a ferrite antenna for medium wave band reception, ANT4 represents a loop antenna for FM band reception, and LP represents an ANTl antenna. Pickup Kool, C
P is the pickup capacitor of ANTl, Ls is the series coil of the speaker, CH, ~CH, is the high frequency blocking coil,
C□ to C1 are high frequency passing capacitors.

In FIG. 6(a), the antenna inputs of the antenna 3 and the ANT 4 are mixed by a mixing circuit 13, and the mixed high-frequency signals are transmitted to the high-frequency input circuit 8 of the vehicle-mounted receiver 1 via a signal transmission path 14. Add to. At this time coil C
H1 is designed to prevent high frequency signals from flowing into the speaker SP.
Further, the coil CH is provided to prevent high frequency signals from flowing into the power amplifier 11. The ground line for the high frequency signal is grounded through a capacitor C3 and connected to the high frequency input circuit 8 through a capacitor C2. The acoustic signal output line 1a is connected to the transmission line 14, but since the audio signal has a low frequency, the coils CH,,CH,,CH
, and the impedance of capacitor C1 can be ignored.
,C,, since it becomes a high impedance for C,
It is possible to superimpose signals of different frequencies on one signal transmission path 14.

According to the configuration shown in FIG. 6(a), even when two antennas are used, conventionally two antenna signal lines and one
What used to require multiple audio signal lines now requires just one common signal line, which is even more effective.

FIG. 6(b) further shows the antenna AN in FIG. 6(a).
In the third in-vehicle audio system of the present invention, in which T3 and ANT4 are installed in the speaker box 12, the grounding line of the high frequency signal is grounded in the speaker box 12 through a capacitor C3.

Conventionally, the antenna and speaker were installed independently and in separate locations, but with the configuration described above, there is no need to install the antenna, and the entire device is miniaturized, so it is especially suitable for automotive acoustics. It is even more effective when carried out on equipment.

In the configuration shown in FIG. 6(b), the speaker box 12 is provided with two antennas, but the present invention is not limited to this, and any one antenna may be provided.

[Effects of the Invention] As explained above, according to the present invention, one signal line can be shared by a low-frequency transmission line and a high-frequency transmission line without signal loop-around, and therefore the number of required cables is reduced. This provides advantages such as the ability to

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the configuration of an in-vehicle audio system according to the present invention, and FIG. 2 is a partially detailed diagram of FIG. 1. Figures 3 to 5 are frequency characteristic diagrams without choke coils, Figures 6 (a) and (b) are conceptual diagrams showing the configuration of another in-vehicle audio system according to the present invention, and Figures 7 and FIG. 8 is a conceptual diagram showing the configurations of two different conventional in-vehicle audio systems. 1... Car receiver body, 2, 3...
...High frequency transmission line, 4, 5, 6, 7...
...Low frequency transmission line, 8...High frequency input circuit, 9...Tuning circuit. IF amplifier, detector, multiplexer, etc. 10...
...Audio adjustment circuit, 11...
power amplifier. 12...Speaker box, 13...
...Mixing circuit, 14...High and low frequency common signal transmission line, ANT1...Front side antenna, ANT2... Rear antenna, ANT...Antenna, ANT 3
・・・・・・Medium wave band antenna, ANT4...
...FM band antenna, 5pFL...
...Front side left speaker, 5pFR...
...Front right speaker. 5pRL・・・・・・Rear left speaker, 5pR
R......Rear right speaker, C...
...Low frequency blocking capacitor, C2...
...High frequency passing capacitor. C3・・・・・・High frequency passing capacitor, CH
......High frequency blocking coil, Ll...
...Speaker 5pRL inductance, LP.
......ANTI pickup coil, Cp
......ANTl pickup capacitor, LS...Speaker series coil, CH
□~CH, ...... High frequency blocking coil, C8
~C1......High frequency passing capacitor. Figure 1 In-vehicle sound system Kanshindan

Claims (2)

[Claims] (1) In a vehicle-mounted audio system including an antenna, an audio equipment main body, and an audio signal output means, (a) an audio signal output line of the audio equipment main body connected to a signal line connecting the antenna and the audio equipment main body; and (b) an in-vehicle audio system, comprising an audio signal output means connected via a high frequency blocking filter to a signal line connecting the antenna and the audio equipment main body. (2) In a vehicle-mounted audio system including a plurality of antennas, an audio equipment main body, and an audio signal output means, (c) means for mixing the plurality of antenna inputs, (a') the mixing means and the audio equipment main body; and (b') an acoustic signal output means connected to the signal line connecting the mixing means and the audio equipment main body via a high frequency blocking filter. An in-vehicle sound system characterized by comprising: