JPS6072421A - Voice signal transmission circuit of on-vehicle radio equipment - Google Patents

Abstract

PURPOSE:To enable a microphone to be mounted on a steering wheel by providing a transmission circuit for voice signal not affected by noise between the turning steering wheel and a radio equipment main body provided to a car body not turned. CONSTITUTION:An output of the microphone 20 is given to a low pass filter comprising an L1 and capacitors C1, C2. The said low pass filter is a circuit to prevent a high frequency signal from being detoured and allows a voice signal only to be passed through. A capacitor C4 gives a limit to the amplification factor of an amplifier 22 for a high frequency signal. Thus, the said voice frequency amplifier 22 amplifies only the voice frequency signal and transmits the voice signal to a primary coil 24a of a transmission transformer 24. Moreover, a tape electric wire 260 is wound loosely in spiral around a steering shaft 3. The tape electric wire 260 is formed by bundling plural leads together and molding the leads in the form of a tape by a synthetic resin so as to provide the elasticity. Thus, even if the steering wheel 4 is turned so as to turn the steering shaft 3, a pad 6 keeps the same phase as that of a fixed gear 2, i.e., stationary state.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a transmission circuit for audio signals that are transmitted to a radio installed in an automobile. [Prior Art] A conventional car radio has a main body that transmits and receives radio signals,
It consists of a main body and a microphone section connected by a curl cord to transmit audio signals. When transmitting a signal, hold the microphone in your hand and press C1.
It is necessary to operate the transmitter switch installed on it and speak to it. 1. Therefore, by installing a radio in a vehicle such as a car, the driver himself or herself can activate the 'knead' while driving. Uru no 1. L, driving operation etc. 51' tj
It has to be done with 'L/', which is b:ri. There 1゛, microphone L1 phone and transmit;
The operation switch is installed on the pad part of the steering wheel of the car, which is the place where the driver can easily operate it. However, the steering wheel rotates as the driver handles the vehicle, and the radio is connected to the main unit.

[It is installed on the body side of the J automatic. For this reason, there are technical difficulties in the method of transmitting signals between the rotating part and the non-rotating part. In general, a signal transmission method using sliding contact is used to connect the horn switch installed on the pad and the vehicle body. II rib contact (there! This is γ'. It is not suitable for retransmitting signals. Also, since it is necessary to transmit many other signals such as operation No. 16, it is necessary to install a large number of 1N) wires. Therefore, it is difficult to connect the rotating part and the fixed part using shielded wires for each signal line.However, if the signal is transmitted using the non-sealed wire and covered, it will be difficult to connect the rotating part and the fixed part using shielded wires. GJ is easily affected by induced noise signals, and there is a problem in transmitting audio No. 19 with 1°jI product 7' (C). It was designed to provide an audio signal transmission circuit that is unaffected by noise between the rotating steering wheel 71ζ ear and the radio body installed on the non-rotating vehicle body side, and provides a circuit for transmitting audio signals that is not affected by noise. An object of the present invention is to realize an in-vehicle radio device installed in a wheel, and to easily perform radio frequency reception operations even while driving a car. (Structure of the Invention) [111 et al. A microphone [1 phone] is installed to convert audio into an electrical signal, an audio frequency amplifier that amplifies the audio signal output from the microphone [4], and an audio frequency amplifier 1 for the audio frequency amplifier.
The secondary coil is a transmission transformer with a secondary coil connected to the transmission line. a balanced transmission line for transmitting the output signal of the transmitting transformer to the radio main body; and a receiving circuit, the primary and secondary coils being connected to the balanced transmission line, and the secondary coil being connected to the audio signal input terminal of the radio main body. The present invention relates to an audio signal transmission circuit for an on-vehicle radio, which is comprised of a transformer and the like. A first feature of the present invention is that a microphone, an 'I j' frequency amplifier and a transmission transformer for amplifying ('I j') output signals from the microphone are provided in a steering wheel of an automobile, for example, in a pad portion. It is difficult to send the 4r, 5; output from the microbond to the microphone end of the 11°l radio, so the P!l city IR which amplifies only the audio frequency band] wave amplification:! :niJ,
This increases the level of the audio signal for transmission, suppresses the effects of noise induced on the line, and improves the S/N ratio. Second
The main feature is the transmission transformer in the steering wheel section.
On the side of the vehicle that does not rotate, the I5 has a receiving transformer installed in the steering column. These transmitting/receiving transformers are equipped with a transmitting system consisting of a microphone and an amplifier, the fj transmission line, and the radio equipment installed on the vehicle body, all of which are isolated to avoid noise from each other. Preventing them from influencing each other. The third 12i fish is sent (;
'I' The signal transmission path between the lance and the receiving transformer is a balanced transmission line. This balanced transmission line μ is realized by arranging multiple signal lines in a flat tE, making them into a tape shape with synthetic resin, and using a rolled tape wire.The transmission line is balanced at t1ξ. Therefore, the in-phase induction power generated between the two wires (3, 1, and 2) is equal in size, so that the outside of the in-phase component can be removed by the receiving transformer, improving the S/N ratio.Balanced transmission The line is used ungrounded, but the transmitter 1 to the secondary coil of the lance or the receiver (both or either of the neutral points of the primary coil of the lance may be grounded.In addition, the receiver 1 ~ You may ground one terminal of the primary coil of the lance. Even when grounded in this way, the balance is maintained and the d3 compensation 1 tone characteristics are not affected. The receiver 1 ~ lance is , the flat pot i transmission line is made as short as possible, rounded to prevent induced noise, and installed near the steering wheel of the steering=1 ram, and the receiving I
- It is best to connect the lance and the wireless unit with a wired coupler. Also, for the balanced transmission line, use a tape wire and connect it with a wired wire.
It is best to connect the transmitting transformer and receiving transformer directly by winding it loosely around the link chain 71 to absorb the rotation of the steering wheel. If you do this, the transmission product rt and durability tl will be improved. +
,. [Embodiment] The present invention will be explained in detail below using a specific embodiment. Fig. 1 is a block diagram of a high j+Ifi,! bow transmission N path according to an embodiment of the present invention. On the pad part 6 of the steering wheel of the car, there is a microphone 2o that converts the convex voice signal into an electric one, an audio frequency amplifier 22 that increases the number by 11'1, and an audio frequency amplifier. A swim transformer 24 is provided for transmitting the output power to the balanced transmission line 26.The balanced transmission line 2o is connected to one of the receivers 1tj and t-lance 28 mounted on the steering column. 3, which is connected to the secondary coil 2ε3a, and the secondary coil 28b of the receiving transformer 28 (Y, stage 1 on the intermediate side. The output of the microphone 20 is Ll, C1,
It is connected to a low pass filter configured by C2-r. The 1-bus filter is a circuit that prevents high-frequency signals from going around, and is a filter that allows only audio signals to pass through. In addition, a shielded wire is used between the microphone 1 and the low-pass filter 21. The output signal of the low-pass filter 21 is sent to an audio frequency amplifier 22. The audio frequency amplifier 22 is: J
From the crumb, an electric current of J and f1 is applied to the supply n'i line 221 and the ground 223. The connector die A-de ZD1 and the parallel capacitor C5 are constant voltage circuits for applying bias to the transistors 1 to 1'r1. In addition, capacitors CJ3 and C7 are coupling compatible, and resistor 1<4 ・(A bias (resistor, C61, 1, bypass capacitor is open) connected to -1 mitsuta. Also, transistor ゛11゛A 2" conductor C/+ is connected between 1 and 11199. The effect of this condenser C/I limits the amplification degree of the high frequency part of the amplifier 22. Therefore, this audio frequency (11199) amplifier 2
2 amplifies the power of the B voice frequency and transforms the transmission transformer 24's 1 logo J Ill 24. To a? :'i-side signal 4 is sent too much. Signal VA between transmission 1 to lance 24 and audio frequency amplifier 22
222 uses a shield kufl. Also, the secondary coil 2 /I) of the transmission transformer 24 and the steering = 1
The receivers 1, 11 provided on the ram 1 and the primary coil 28a of the nonce 28 are connected by an elastic tape wire 260. The 1-line 260 constitutes a balanced circuit and is not sealed. Further, the secondary terminal of the receiving transformer 28 is connected to the main body of the radio device through a shielded wire 281. Tape wire 2 (30 is shown at 71J in FIG. 33) is loosely (screw-wound) around the steering shaft 3 as shown in FIG. There is one that is formed in the form of a tape (J). A connector 17 is connected to each of these llj, respectively. The installation method is not shown (^11 cross-sectional view C is shown).The steering wheel has a non-rotating pad.
Those with + i are shown. A fixed tooth f1 (2) is fixed to the upper part of the steering column 1. The fixed gear 2 meshes with the lower end gear of the MW gear 5, which is rotatably supported by the boss portion 8 of the steering link wheel. A stationary gear 7 rotatably attached to the upper end of the steering shaft 3 via a bearing is mounted at the front stage a3, and this gear meshes with the upper end gear of the "t1 star gear 5." A pad 6 is fixed to the stationary gear 7. The stationary gear 2 and the stationary gear 7 have the same diameter and the same number of teeth, and the lower end gears of the planetary gears 5 and 11 also have the same diameter and the same number of teeth. Therefore, the fixed gear 2 and the stationary gear 7 are held in the same phase. Therefore, even if the steering link wheel 4 is rotated and the steering wheel 1 is rotated, the pad 6 is kept in the same phase. It maintains the same phase as ゛2, that is, a stationary state. Pad q is equipped with the above-mentioned microphone 2□0, audio frequency amplifier 2'2, and transmission (L'; l~ lance 24). Pad q. The =1 connector 7a of the tape electric wire 26Ci is connected to the terminal provided at the lower end of the section, and the tape electric wire 266 is helically wound and housed in the internal space of the stationary gear 7.One connector oVA"F 17b is It is connected to the connector installed on the boss part 8 of the steering wheel.On the other hand, the connector of another j-p electric wire 261 is similarly connected to the lower surface of the boss part 8 of the subno ring boiler, and The electric wire 261 connects the fixed gear 2
The screwdriver [ ) (is stored in the internal space of the tape electric wire 2
The other terminal of 61 (, 1 is connected to the steering column 1. In this way, the balanced transmission line is connected to the steering link column 1 of the fixed part and the steer link wheel of the rotating part. It is used for signal transmission. Figure 5 shows the arrangement of the microphones arranged on the pad of the steering wheel (6). The microphone 20 is attached to the surface 6a of the steering wheel pad. A container 202 is provided for this purpose.A vibration-proof wall 204 and a sound-proof wall 206 made of urethane foam etc. are stepped on the inner peripheral surface of this container 202.The microphone 1 cophone 20 is It is installed at a certain distance from the front face of the homo part 6alp+ at the rear of PJiaKCJ.
An air chamber 20 with a certain capacity is provided between the back of the microphone 11 and the bottom of the soundproof wall 20. Pad the microphone like this: a certain distance from the top surface. ,□,. , Akira. , l 6'Z +! l:
k: □i" (M j3 (7) 7% e ?I2,1.yoO-'Clft1 Ill '9"6 c:
J = ifir. picture. For example, yo:,, 7-a, 'hot, 1, e2. It was possible to eliminate the sliding noise caused by movement, rolling, and ejection. □ The above is a summary of 1. In the Ming Dynasty, a transmitter was installed on the steering wheel, and a transmitter was installed on the side of the m1 body.
This is a signal transmission circuit for transmitting audio signals. Between the receiver and the department, it is
- A transmitting IJ lance is installed in the 1, :S), and a balanced signal transmission is used in the signal transmission path. Transmission/reception I l-balanced signal isolated by lance-
Since it uses a transmission line, it cancels the common mode noise induced in the transmission line.
1 to 1r] 1 t6 1j' A 71.1-/+< T”
Since A A - V ', \jijfEl is amplified by an audio frequency amplifier and sent out, the S/
Improves N ratio. Because these effects occurred, microphone 1 of the car radio
By using the cohon on the steering wheel, it is possible to transmit high-quality audio signals to the radio unit itself, which improves the driver's performance while driving. .

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a transmission circuit No. 15 of our company according to a specific embodiment of the present invention. FIG. 2 is a more detailed circuit diagram of the audio signal transmission circuit according to the same embodiment. 3rd: Figure is a 17 (-) diagram of the tape electric wire used in the same example. Figure 4 is the sound II lij used in the same example.
FIG. 3 is a cross-sectional view of the structure of the steering wheel for explaining the installation of the signal transmission circuit. Figure 5 shows the same example.
It is a cross-sectional view showing the structure of a single handler for the steering wheel l\ of the e-microbon. 1...Steering column 3...Steering shirt 1~4'...Steering link boiler 6...Pad ε3...Boss part 20...Microphone [1 phone 22...Sound 1 No. 1 Frequency amplifier 24...Transmission l/lance 26...Balanced transmission line 28...Receiving transformer 30...Wireless is main body special z1 Applicant i1 Ishin Seisei Co., Ltd. +Q,;
Tosei Co., Ltd. Agent Patent Attorney Hirotoshi Okawa]! l! -l- Shu Mutsuya 1ii1 Patent Attorney [Maruyama Meiji University Figure 3 3-゛

Claims (1)

[Scope of Claims] (1) Disposed on the automatic snoring wheel,
A microphone that converts sound into an electrical signal, an audio frequency amplifier that amplifies the audio signal output from the microphone, and one logo on the audio frequency amplifier and two on the transmission line.
The transmission transformer to which the Logo 1 coil is connected and the balanced transmission line that transmits the output signal of the Hl lance to the main body of the radio are connected to the military service 1 transmission line, and the primary coil is connected to the military service 1 transmission line. 2nd 21
- The in-vehicle line consists of the receiver 1 to the radio, which are connected to the main body's ?11 signal human horn end. The range i of the special R'l crystal is characterized in that the transmission Wil k'8 is ungrounded.
In-vehicle wireless (Iku's audio No. 115 transmission circuit) described in Ifi. Special ii'i take'1. '＋R'l'
The voice transmission circuit of the in-vehicle radio according to claim 1. (4) At least one end of the primary coil of the receiving lance is grounded. .'1 for vehicle use according to claim 1 (-line 1 generation r'1)
j'・Signal transmission circuit. (5> Said reception 1 Herans tJ, , steering wheel dani 1
It is arranged in a part close to the buff 1 to part of the steering wheel of the receiver transformer, and
1. Vehicle-mounted device 1 as described in item 1 of the scope of the 1'J R'l crystal search, characterized in that the audio signal input terminal of the main unit is connected with a shield loop. (6) The balanced transmission line consists of a plurality of conducting wires arranged in a flat 1J, and covered with a synthetic resin integrally in the form of a loop. [111 (111) for vehicle-mounted use described in paragraph 1] 1 ((audio signal transmission of line machine) Ijil road.