JPS6361222B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering operation board signal transmission device that transmits signals between a device on a vehicle body and a steering operation board near a steering wheel, and in particular, a steering operation board signal transmission device that transmits signals between a device on a vehicle body and a steering operation board near a steering wheel. The present invention relates to a steering operation board signal transmission device comprising an acoustic-electrical transducer.

In a vehicle, the steering wheel is the closest to the driver, and it is also closest to the driver's hands, so in order to improve operability, it is necessary to install an operation board equipped with key switches for controlling the on-board equipment.
It is preferable to install it in the center of the steering wheel.

However, because the steering mechanism that transmits wheel rotation to the steering shaft is complex,
It is difficult to wire the signal cable that connects the operation board installed in the center of the steering wheel (steering operation board) and the fixed control unit. It is necessary to arrange the slip rings for the steering mechanism in a manner that does not interfere with the operation of the steering mechanism, and wiring these is quite difficult because the space allotted to the steering mechanism is limited.

Therefore, the applicant proposed a method (Japanese Patent Application No. 132926/1982) in which the operating board and the fixed control unit are connected using a slip ring and a brush, and power and signals are transmitted through the line. Proposed. According to this, the power supplied to the operation board and the large amount of information generated from the operation board can be transmitted without using many lines.

By the way, when a wireless communication device is installed on the vehicle,
Since the communication device has to be installed at a considerable distance from the person making the call, such as the driver, the talking part such as the microphone is generally separated from the main body of the communication device to prevent noise from being transmitted from the surroundings. The talking part and the main body of the communication device are connected with a cord, and when communicating, the talking part is removed from the main body of the communication device and brought closer to the person making the call. However, when the driver makes a call, he or she must hold a microphone or the like with one hand, which means that the driver must drive with one hand, which is dangerous. Since the driver has the most opportunities to talk on the phone in a vehicle, it is desirable to enable the driver to talk on the phone safely.

A first object of the present invention is to provide a steering operation board signal transmission device that allows a driver who is driving a vehicle to safely communicate with people outside the vehicle. The third purpose is to faithfully transmit the information to the communication device without noise, and the third purpose is to prevent the structure of the steering wheel from becoming complicated and increasing in volume.

In order to achieve the above object, in the present invention, an acoustic-electrical transducer such as a microphone and a switch means are provided on the operation board on the steering wheel, and a signal modulated by a signal from the acoustic-electrical converter and a switch means are provided. A signal modulated according to the operation is transmitted via a transmission means such as a slip ring.
The electric signal, that is, the audio signal generated by the acousto-electrical converter is sent to a control device provided with a demodulator on the vehicle body, and is applied to a wireless communication device on the vehicle in accordance with a predetermined operation of the switch means.

According to this, the driver can talk to people outside the vehicle via the wireless communication device without having to hold a microphone or the like, so that the driver can safely talk on the phone while holding the steering wheel with both hands while driving the vehicle. Since the steering wheel is located near the driver, by using a microphone with a certain degree of directional sensitivity, it is possible to eliminate sounds or noise emitted by people other than the driver and input only the driver's voice to the communication device. .

As shown in Japanese Patent Application No. 56-132926 filed by the present applicant, when passing a signal and DC power through one slip ring, only one system of slip ring and brush is required, which simplifies the configuration. Uruga,
Since noise is likely to occur in the transmission path, the S/N (signal/noise) ratio of the transmitted audio signal is likely to deteriorate.

Therefore, in one preferred embodiment of the present invention, two systems of slip rings and brushes are provided to connect the vehicle body and the steering operation board, and power from the on-board battery is transmitted to the steering system through one system of slip rings and brushes. Electric signals, including audio signals, are sent to the operation board and transmitted through another slip ring and brush. By forming the slip rings concentrically around the steering axis, multiple transmission lines can be configured without complicating the configuration. According to this, the audio signal can be transmitted without deteriorating the S/N ratio.

In order to confirm the signal reception process and control the status display on the steering wheel operating board, it is preferable to transmit a predetermined signal from a device on the vehicle main body side to the operating board on the steering wheel. Accordingly, in one preferred embodiment of the present invention, a demodulation circuit is provided in the steering operation board, and a modulation circuit is provided in a device on the vehicle body side, so that predetermined information is transmitted from the vehicle body side to the steering operation board. According to this, highly reliable information transmission can be performed, and the vehicle speed, engine rotation speed, etc. can be displayed on the operation board on the steering wheel.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an embodiment. 1st
This will be explained with reference to the figures. In this example, the steering wheel operation board includes a constant voltage power supply 7.
0, a microcomputer unit 80 which is a transmission control device, a key switch 90, a first modulation circuit, that is, an FM modulation circuit 95, a second modulation circuit, that is, an FSK modulation circuit 100, an FSK modulation circuit 110,
first acoustic-to-electrical conversion means or microphone;
MC1, MC2, differential amplifier DFA and relay
It has RL.

The microphones MC1 and MC2 are placed facing the same direction (toward the driver's mouth) at a predetermined interval, and their output ends are connected to different input ends of the differential amplifier DFA. As a result, the sound applied to microphone MC1 and MC
Since the difference in the sound applied to the two is amplified by the DFA,
A large output signal can be obtained for sound coming from the direction in which MC1 and MC2 are arranged, that is, from the direction of the driver. In other words, noise from the side is canceled out, and only the signal corresponding to the driver's voice is greatly amplified.
It is applied to the FM modulation circuit 95.

In this embodiment, the control unit on the vehicle body side includes a constant voltage power supply 120, a microcomputer unit 130, an FSK modulation circuit 150, an FSK demodulation circuit 160, an FM demodulation circuit 170, and a telephone set.
TEL, radio communication equipment for mobile devices, i.e. telephones
TRX, connection switching means or branch connection circuit 180, amplifier AMP, speaker SP and relay
Equipped with RL2.

The output end of the FSK modulation circuit 100, the input end of the FSK demodulation circuit 110, and the output end of the FM modulation circuit 95 are connected to the slip ring SA1. The input end of demodulation circuit 170 is connected to slip ring SA2. Slip rings SA1 and SA2 are electrically connected to each other via brushes BA1 and BA2. An on-vehicle battery is connected to the other transmission line, that is, the slip rings SB1, SB2 and the brushes BB1, BB2, via an ignition key switch SW.

Fig. 2a shows the vicinity of the driver's seat of a vehicle equipped with the device shown in Fig. 1, and Fig. 2b shows the appearance of the steering wheel portion. Figures 2a and 2
This will be explained with reference to figure b. A telephone 2 is installed on the left side of a driver seat 1, and a speaker SP is placed in front of it. steering wheel 3
An operation panel is provided in the center of the steering wheel 3 and is placed above the steering wheel 3. The operation panel is equipped with the same 12 key switches 0 to 9, * and # as the pushphone, horn switches HS1 and HS2 on both sides, clear key CLR, hold key HOLD, call/off key CALL/OFF, and microphone MC1. It's on. MC2 is placed below microphone MC1.

FIG. 2c shows an attachment structure between the steering wheel 3 and the steering operation board and the vehicle body. This will be explained with reference to FIG. 2c. The support 38 is fixed to the support 41 and the gear 39
is rotatably supported. The gear 39 is fixed to the vehicle body. Support 41 is steering shaft 4
0, and the steering wheel 3 is connected to the support 41. Support 41 rotatably supports gears 39 and 42. 43
are gears 43a and 43b with the same number of teeth at both ends.
It is a connecting member having a structure, and is rotatably supported by the support 41. Gears 43a and 43b mesh with gears 39 and 42, respectively. The printed circuit board 44 of the steering operation board and the operation panel 31 are fixed to the gear 42. The gears 39 and 42 have the same number of teeth. With such a configuration, the operation panel 31 and the like do not rotate as the steering wheel is rotated. In this embodiment, when the steering wheel 3 is rotated, the support 41 and the steering shaft 40 are rotated to perform steering operation.
Since a and 43b and 39 and 42 have the same number of teeth, the connection member 4 due to rotation of the support 41
The relative movement amount (angle) between the support 41 and the gear 39 caused by the arc-shaped movement of the gear 39 and the relative movement amount between the support 41 and the gear 42 are equal, and the gear 39 is fixed and the gear 42 is fixed relative to the gear 39. As a result, even if the steering wheel 3 rotates, the operation panel 31 does not rotate. 4
5 is a disk fixed to the vehicle body, and metal slip rings SA2 and SB2 are formed concentrically on the surface facing the steering wheel 3. 46 is a disk fixed to the steering operation board, and metal slip rings SA1 and SB1 are formed concentrically on the surface on the gear 42 side. The steering wheel 3 has brushes BA1, BA2, BB1 at positions facing the slip rings SA1, SA2, SB1 and SB2, respectively.
And BB2 is fixed. Brush BA1 and BA2
And brushes BB1 and BB2 are electrically connected. Each brush BA1, BA2, BB1 and BB
2 are in contact with each corresponding slip ring by the force of a compression coil spring. The slip rings SA1, SB1 and the steering operation board are connected with lead wires. The steering shaft 40 is grounded, and the ground line of the steering operation board and the steering shaft 40 are electrically connected.

Figures 3a and 3b show the configuration of the electric circuit on the steering operation board. First, 3rd a
This will be explained with reference to the figures. The key switch 90 connects the five output ports P1 of the microcomputer 80.
-P5 and four input ports P6-P9 are configured with a large number of switches connected in a matrix. The contacts of these switches are opened and closed by operating predetermined portions on the operation panel 31. The FSK modulation circuit 100 has an input side connected to three output ports P10 and P of the microcomputer 80.
11 and P12, and its output end is connected to slip ring SA1. The FSK modulation circuit 100 includes a counter CO1, D-type flip-flops F1 and F2, NAND gates NA1 to NA5,
Inverter IN1 to IN5, transistor Q1, Q
It is composed of 2nd class.

The FSK demodulation circuit 110 has an input end connected to the slip ring SA1, and an output end connected to the input port P13 of the microcomputer 80. The FSK demodulation circuit 110 has a Schmitt trigger
ST1 (Motorola MC14583), counter CO
2 (Motorola MC14018), CO3, NAND gate NA6 to NA19, inverter IN6 to IN2
It is composed of 2nd class. The FSK demodulation circuit 110 is divided into functions: ST1, F3, F4, F5, F
6. Waveform shaping/differentiation circuit consisting of NA6, NA7, IN6~IN10, etc., F7, CO2, F8, NA8~
An external input priority circuit consisting of NA16 and IN11 to IN17, a reference signal generation circuit consisting of F9, F10, NA17, IN18 and IN19, and F
11, F12, CO3, NA18, NA19 and
It is composed of a frequency discrimination circuit consisting of IN20 to IN22.

Output port P14 of microcomputer 80
A buzzer BZ is connected to the output port P15 via an inverter, and a relay RL1 is connected to the output port P15 via an inverter.

Referring to FIG. 3b, the above-mentioned relay
One of the contacts of RL1 is connected to the power line from the slip ring SB1, and the other contact is connected to the constant voltage circuits RE2, RE3, RE4 and RE5.
It is connected to. The output end of the power supply circuit consisting of the three-terminal constant voltage circuit RE1 etc. and a capacitor is directly connected to the power supply line of the electric circuit shown in FIG. 3a. In addition
RE3 is a switching type constant voltage circuit (CP4801)
It generates a stable voltage of ±12V for operational amplifiers. Microphones MC1 and MC2 are
It is connected to a differential amplifier DFA made up of operational amplifiers. A high-pass filter HPF configured using an operational amplifier is connected to the output terminal of the differential amplifier DFA. A low-pass filter LPF configured using an operational amplifier is connected to the output end of the HPF. The output signal of the low pass filter LPF is
Amplify with amplifier AMP and output FM via capacitor
It is applied to the input terminal Audio in of the modulator FMM.
At the FMM input terminal Audio in, there is a variable resistor VR1.
A predetermined DC bias voltage is applied. The variable resistor VR1 sets the center frequency of the FM modulated wave. The FM modulator FMM is made of one integrated circuit, and the FM modulation circuit 95 is the FMM.
It consists of an electric coil, capacitor, resistor, etc. connected to each terminal. FM modulator FMM
The output terminal C of is connected to the slip ring SA1 via a capacitor.

Figures 4a and 4b show the electrical circuitry of the device on the vehicle body. First, referring to Figure 4a,
The microcomputer 130 is connected to an FSK modulation circuit 150 and an FSK demodulation circuit 160. Output terminal of FSK modulation circuit 150 and FSK
The input terminal of the demodulation circuit 160 is a slip ring SA.
It is connected to 2. FSK modulation circuit 150 and
The configuration of the FSK demodulation circuit 160 is as described above.
FSK modulation circuit 100 and FSK demodulation circuit 110
It is made the same as

This will be explained with reference to FIG. 4b. The constant voltage power supply circuit 120 includes an electric coil CHC for high frequency blocking. One end of the CHC is connected to the on-board battery via the ignition key switch SW, and the other end is connected to the slip ring SB2.

The input terminal of the FM demodulation circuit 170 is a slip ring.
It is connected to SA2. The FM demodulation circuit 170 is
It consists of a ceramic filter CFT, an integrated circuit FMD for FM signal demodulation, a low frequency amplifier AM1, etc. The power supply of the FM demodulation circuit 170 is relay RL2.
is supplied through the contacts. FM demodulation circuit 170
The output end of is connected to the contact of relay R5. The amplifier AMP connected to speaker SP is
It consists of a CLP, a low frequency amplifier AM2, and a power amplifier PA. The power amplifier PA has an output transformerless (OTL) configuration. The input of amplifier AMP is connected to one contact of relay R2.

Other ports of the microcomputer 130 include a branch connection circuit 180, a transistor that controls a horn drive relay R6, and a buzzer.
An inverter that drives BZ is connected. The branch connection circuit 180 includes a telephone TEL, a mobile
TRX, FM demodulation circuit 170 and amplifier AMP are connected. In the telephone TEL block,
DI is the dial code output terminal, CP is the 1200 baud clock pulse output terminal, PS is the power on/off control input terminal, CI is the regulation instruction signal (“0”: callable,
HK is a hook signal (on-hook/off-hook) output end, T is a transmission audio signal output end, R is a reception audio signal input end, and POW is a power supply end. HK1 and
Both HK2 are hook signal input terminals. The branch connection circuit 180 includes relays R1, RB, and R3.
(RL2), R4 and R5, which are controlled by a microcomputer 130.

Referring to FIG. 3a, the FSK modulation circuit 100 (1
50) will be explained briefly. A constant period (T/4) pulse signal is applied to the input end of the FSK modulation circuit 100 from the output port P10 of the microcomputer 80. Counter CO1 divides this pulse and outputs a pulse with period T to output terminal Q2.
A pulse signal with a period of 2T is generated at the output terminal Q3.
The pulse signal with a period of 2T is also applied to an FSK demodulation circuit 110, which will be described later. The output port P11 of the microcomputer 80 is an output terminal for data to be transmitted. The flip-flop F1 outputs a level corresponding to the data from the port P11 (high level H for data "1", low level L for data "0") in synchronization with the rise of a pulse signal with a period of 2T applied to the clock input terminal CLK. ) to the output terminal Q. Therefore, when the data is "1", the output terminal Q of F1 becomes H, and the output terminal Q2 of CO1 is passed through the NAND gate NA1 to the output terminal of the NAND gate NA3.
When a pulse signal with T period appears from Q3 of CO1 and the data is "0", the output terminal Q of F1 becomes L, and a pulse signal with period T of 2T from Q3 of CO1 is sent to the output terminal of NAND gate NA3 via NAND gate NA2. appears. The output port P12 of the microcomputer 80 outputs a signal that controls permission/inhibition of output of the FSK signal to the transmission path. Port P1
When 2 is high level H, CO1 output period 2T
In synchronization with this pulse, the output terminal Q of flip-flop F2 becomes high level H. This allows the gate
NA4 and NA5 open, and T from the output end of NA3
Or the 2T period signal is NA4, IN5, and IN
4 and NA5 to transistors Q1 and Q2, respectively. At the rising or falling edge of that signal, transistor Q1 or Q
2 turns on, charging and discharging the charge in the capacitor C1. As a result, slip spring SA1
At the rise and fall of the pulse signal,
Pulsed signals of positive and negative polarity are generated.
When port P12 is at low level L, Q of F2 becomes L, gates NA4 and NA5 close,
A low level L and a high level H are applied to transistors Q1 and Q2, respectively. In this state, transistors Q1 and Q2 are both turned off and do not output a signal to slip ring SA1.

Figure 5a shows the FSK of Figures 3a and 4a.
The approximate timing of the frequency discrimination circuit is shown. Fifth
The operation of this circuit will be explained with reference to FIG.
A 1/4T cycle clock pulse from the microcomputer port P10 is always applied to the flip-flop F11 and the clock input terminal CK of the counter CO3. The external FSK signal is
It is applied to the J input terminal of F11, the clock input terminal of flip-flop F12, etc. In this embodiment, the FSK signal is set so that the period is T when the data is "1" (high level H) and the period is 2T when the data is "0" (low level L). In the initial state, counter CO3 is reset. When the FSK signal arrives and the J input terminal of F11 becomes high level, the Q output terminal of F11 is set to H and the output terminal of F11 is set to L in synchronization with the clock (T/4). This releases the reset of the counter CO3, and the counter CO3 starts counting the clock (T/4). FSK signal is T
If the period is 0, 1, 2, 3, the counter CO3 will be 0, 1, 2, 3.
After counting, the FSK signal becomes H,
Counter CO3 is reset again. At the same time, the flip-flop F12 sets the level of the input terminal D, that is, H, to the output terminal Q.
A high level H corresponding to data "1" is outputted to the output terminal of F12 as a demodulated output signal.
When the FSK signal has a 2T period, counter CO3 counts 0, 1, 2, 3, 4, 5, and at count 5, NAND gate NA19 and inverter IN
22, a reset signal is applied to flip-flop F11. F11 is thereby reset, and the output terminal Q is set to L and the output terminal is set to H. This resets the counter CO3. Then, when the FSK signal becomes high level H, the flip-flop F12 sets the output level L of F11 to the output terminal Q, that is, the demodulation output terminal. Therefore, when a predetermined FSK signal is applied, this circuit demodulates the signal and outputs data.

However, if noise or the like similar to the FSK period of T period is applied to the frequency discrimination circuit, in response to the noise, the Q of flip-flop F5 is set to H, and a high level H is output as a demodulated output signal. If no signal and nozzle are applied thereafter, the Q output terminal of flip-flop F12 remains set to the high level H. If this state continues for more than a predetermined time, the microcomputer 80 (or
30) mistakenly assumes that data has arrived and starts reading the data. In this embodiment, a reference signal generation circuit and an external input priority circuit are provided to prevent this.

FIG. 5b shows the operation timing of the reference signal generation circuit. This will be explained with reference to FIG. 5b. Port P
The clock pulse of T/4 period from 10 is applied to the clock input terminal CK of flip-flops F9 and F10.
is applied to the FSK modulation circuit 100 (or 1
A pulse signal with a period of 2T whose frequency is divided by 8 by the counter CO1 of 50) is applied to the J input terminal of F9, etc. Flip-flops F9, F10, etc. operate as a differentiating circuit, and the output terminal of inverter IN19 has a pulse width (period of high level H) of T/4 and a period of
A 2T reference signal is obtained. Since this reference signal has a period of 2T, when it is applied to the frequency discrimination circuit, the frequency discrimination circuit discriminates this signal as data "0" and sets the demodulated output signal to a low level L.

FIG. 5c shows the operation timing of the external input priority circuit. This will be explained with reference to FIG. 5c. The FSK signal from the waveform shaping/differentiation circuit (signal output from NA7) is applied to inverter IN10 and NAND gate NA8. The output signal of the inverter IN10 is applied to the flip-flops F7, F8 and the NAND gate NA13.
The output signal from NA8 is applied to the reset input R of counter CO2. At the clock input terminal CK of counter CO2 and flip-flop F7,
A clock pulse of T/4 period is applied.

When the FSK signal is applied to the external input priority circuit and the input terminal of inverter IN10 becomes low level L,
In synchronization with the T/4 period clock pulse, output terminals Q and of flip-flop F7 are set to H and L, respectively. The signals from the output terminals Q and F7 are respectively connected to the NAND gate NA1.
4 and NA15. nand gate
NA14, NA15, and NA16 are circuits for selecting signals, and depending on the state of the output terminal Q of the flip-flop F7, the FSK signal or the reference signal from the reference signal generation circuit is selectively selected.
It is applied to the frequency discrimination circuit described above. When the Q of flip-flop F7 is set to H, the FSK signal from inverter IN17 is applied to the frequency discrimination circuit. Furthermore, when the output terminal of F7 is set to L, the reset of counter CO2 is canceled,
CO2 starts the clock counting.

When the period of the FSK signal is T, the counter CO2 counts 0, 1, 2, 3, and then the next
It is reset again due to a change in the state of the FSK signal.
Count again 0, 1, 2, 3. FSK
If the signal period is 2T, flip-flop F7
After is set, the counter CO2 will be 0, 1,
It counts 2, 3, 4, 5, 6 and is reset. In other words, when there is an FSK signal, regardless of whether the period of the FSK signal is T or 2T, the reset signal H is not applied to the reset input terminal R of the flip-flop F7, so F7 outputs the output terminal Q.
and are held in the H and L states, respectively. Also, in this state, a high level H is output to the output terminal Q of the flip-flop F8 at a predetermined timing, so that it is input to the inverter IN10.
The FSK signal is applied to NAND gate NA14 via NAND gate NA13 and inverter IN17. Here, since a high level H is applied to the other input terminal of the NAND gate NA14,
The FSK signal is applied to the frequency discrimination circuit via NA14 and NA16. Also, at this time, since one input terminal of the NAND gate NA15 is at a low level L, the reference signal from the reference signal generation circuit is NA1.
No output from 5.

When the FSK signal is no longer applied, the counter CO
2, the reset at count 6 is no longer applied, so counter CO2 is 0, 1, 2, 3, 4,
Continue counting 5, 6, 7, 8, 9. C.O.
The count value of 2 is 9, that is, from the start of counting
After 3T, the flip-flop F is connected via NAND gate NA9 and inverter IN16.
A high level (reset level) H is applied to the reset input terminal R of F7, and F7 is reset. As a result, the output terminals Q and of the flip-flop F7 are inverted to L and H, respectively. When F7 becomes H, a reset signal is applied to counter CO2. This reset signal is then applied to the inverter.
A low level L is applied to IN10, and F7 is L.
It continues until it is set again. When the levels of output terminals Q and of flip-flop F7 are inverted, NAND gate NA14 closes and NA
15 is opened, and the reference signal from the inverter IN19 is applied to the frequency discrimination circuit via the NAND gate NA16.

FIG. 6 shows a schematic signal waveform of the entire device.
Referring to FIG. 6, a case will be described in which signals are sent from the steering operation board shown in FIGS. 3a and 3b to the devices shown in FIGS. 4a and 4b. As mentioned above, while outputting a high level H to the output port P12 of the microcomputer 80 and outputting a T/4 cycle clock pulse to P10, the level H or L is set depending on the data to be transmitted to the output port P11. Then, a pulse signal with a period of T or 2T depending on the level, that is, an FSK signal, is generated at the output terminal of the inverter IN5, etc., and as a result, when the FSK signal rises and falls, the transmission line including the slip ring SA1 Signals of positive and negative polarity are generated.

On the other hand, when audio is input to the microphones MC1 and MC2, the audio signal is amplified by the differential amplifier DFA, and then passed through the high-pass filter HPF and low-pass filter.
FM modulator via LPF and amplifier AMP
Applied to FMM's Audio in. This results in
At the output end of the FM modulation circuit 95, a relatively small amplitude sine wave signal frequency-modulated with the audio signal appears, and this signal is applied to the transmission path including the slip ring SA1 via a capacitor.

Therefore, a signal in which the FSK signal and the sinusoidal FM signal modulated by the audio signal are superimposed appears on the transmission path. This signal is a slip-spring
It is applied to the device on the vehicle body via SA2.

The signal is applied to FSK demodulation circuit 160. The FSK demodulation circuit 160 extracts only the positive polarity pulse and negative polarity pulse components from the signal in binary form using the Schmitt trigger ST1, converts it into an FSK signal, and then converts it into an FSK signal according to the period of the FSK signal.
Demodulates the FSK signal to data “1” or “0”,
The data is applied to the input port P13 of the microcomputer 130.

On the other hand, the signal from the transmission line is transmitted to the FM demodulation circuit 170.
is applied to The FM demodulation circuit 170 uses a ceramic filter CFT to extract only the FM modulation signal and applies it to the FM demodulation integrated circuit FMD. The FMD demodulates the original audio signal from the FM modulated wave and applies the audio signal to the amplifier AM1.

FIG. 7 shows microcomputers 80 and 13 in FSK modulation circuits 100 and 150 of the embodiment.
0 shows the configuration of the applied signal. To explain with reference to FIG. 7, the signal consists of the first 10-bit mark signal (high level: "1"), followed by 1-bit start bit, 8-bit data, and 8-bit mark signal (high level: "1").
It is written in BCC code of bit. In the 8-bit data, bits 0 to 4 indicate the type of key, and bit 5 indicates key on/off (“1” indicates on/off,
Bits 6 and 7 indicate the key group. In this embodiment, the key groups are divided into three groups: A, indicated by "00", B, indicated by "01", and C, indicated by "10". Group A is the numeric keys (0-9), #, *, clear key CLR and hold key HOLD, key group B is the horn keys HS1 and HS2, and key group C is the call/off key CALL/
It is OFF.

FIG. 8 schematically shows the operation of the device when making a call from the on-board telephone from the steering operation board, and the operation of the device when making a receive operation from the steering operation board. This will be explained with reference to FIG.

Making a call Enter the telephone number of the other party using the numeric keys, * and # on the steering wheel operation board. The microcomputer now stores the keyed-in telephone number.

Have the call-off key CALL/OFF pressed.

When the call-off key CALL/OFF is operated,
Automatically call the recipient of the memorized phone number.

When the called party picks up the receiver (off-hook), hands-free communication becomes possible. Note that if you operate the hold key HOLD here, relay R5 will operate and the microphone MC1 and
MC2 is cut off from the mobile TRX and audio is no longer transmitted from the vehicle.

When the call-off key CALL/OFF is operated again, it is determined that the call has ended and the communication is terminated.

Receiving operation When the other party calls the on-board telephone, a ring tone sounds.

The call-off key CALL/OFF is operated.

When the call-off key CALL/OFF is operated,
The state is the same as when the handset is lifted normally, and the other party's voice is output from speaker SP, and microphone MC1 and microphone on the steering control board are output.
MC2 is connected to the on-board telephone as a transmitter.

When the call-off key CALL/OFF is operated again, it is determined that the call has ended and the communication is terminated.

Figures 9a and 9b illustrate the operation of the steering operation board of Figures 3a and 3b.
The operation of each step of the steering operation board will be explained with reference to FIGS. 9a and 9b.

S1 The contents of the memory are set as initial values, and the status of each output port of the microcomputer 80 is set to the initial level. With this process, the output port P
12 becomes a low level L, and output of the FSK signal is prohibited.

S2 key reading signal output port i.e. P1~P
5. Set the data to be output to the initial value. In this initial data, the bit corresponding to the output port connected to the row line of the key matrix from which reading starts is set to "0" (that is, low level L), and the other bits are set to "1" (that is, high level H).
The value is set to . In this embodiment, the bit corresponding to port P1 is set to "0" in the initial setting.
Bits corresponding to ports P2, P3, P4 and P5 are set to "1".

S3 Output predetermined data to ports P1 to D5. As a result, one of the ports P1 to P5 becomes a low level L, and the other ports become a high level H.

S4 Read the levels of input ports P6 to P9 connected to the column lines of the key matrix. Referring to Figure 3a, input ports P6 to P9 are pulled up to the power supply line Vcc via resistors, and output ports P1 to P5 and input ports P6 to P9 are pulled up to the power supply line Vcc through resistors.
Since each key is connected in a matrix between P9, for example, when key 0 of key matrix 90 is pressed, input port P is set to low level L at output port P1.
The levels of 6, P7, P8 and P9 are L, H, H and H, respectively.

S5 Inverts 1/0 of each bit of the data read in step S4. In other words, take the complement.

S6 Compare the key reading data obtained in step S5 with the numerical value 0. If the value is 0, there is no key input, so proceed to step S13; otherwise,
Proceed to step S7.

S7 Save key reading data to specified memory.

S8 To eliminate the influence of mechanical vibrations, that is, chattering, on the key contacts, wait a predetermined time (for example, 10 msec) for the vibrations to subside.

S9 Read the levels of ports P6 to P9 again.

S10 Calculate the logical OR of each bit of the value read in step S9 and the value saved in the memory in step S7.

S11 Check whether the calculation result in step S10 is not 0. If it is not 0, it is assumed that no key input has been made and the process proceeds to step S31; otherwise, the process proceeds to S12.

S12 Generates an 8-bit key code corresponding to the pressed key from the data "0" bit of the key reading line signal data output to the output ports P1 to P5 and the data read from the ports P6 to P9.

13 Shift the data "0" bit of the key reading row signal data output to the output ports P1 to P15 to the adjacent bit by one bit.

S14 Check whether one key reading scan is completed. If not finished, step
Return to processing from S3.

S15 Since there was no key input, the 8-bit code
The key code is OOH (hexadecimal display).

S16 Load the key code from the previous key reading scan from memory.

S17 Calculate the logical OR of each bit between the old key code loaded in step S16 and the new key code obtained by the current key reading scan.

S18 Check whether the calculation result is 0. If the key is 0, that is, there is no key operation, the process returns to step S2; otherwise, the process proceeds to step S19.

S19 Store the newly generated key code in the memory at a predetermined address.

S20 Check whether the key code belongs to key group A.

S21 Checks if key is pressed or released. The keys of group A, ie, the numerical keys, * key, # key, clear key CLR, and hold key HOLD, are valid only when pressed, so if the keys are released, the process jumps to step S2.

S22 The buzzer sounds once to confirm key input.

S23 Check whether the pressed key belongs to group B. The keys of group B, namely the horn keys HS1 and HS2, are enabled both when pressed and when released.

S24 Sends the generated key code data to the transmission line and notifies the device on the vehicle body that a key input has been made. This process will be explained in detail later.

S25 Check whether the data was sent correctly in the data transmission in step S24.

S26 Check whether the pressed key belongs to group C. Regarding the keys of group C, that is, the call-off key CALL/OFF,
Each time a key is pressed, the key on/off data is inverted.

S27 From memory, call-off key CALL/OFF
Load data indicating the on/off status of the

S28 From the key code and the data loaded in step S27, a new key code with the on/off state of the call-off key CALL/OFF reversed is generated. For example, if the call-off key was turned on in the previous operation, key code data indicating that the call-off key is turned off is generated in the current key operation.

S29 Similar to step S24, S30 checks whether the data was sent correctly in step S29 and data transmission.

S31 Inverts the contents of the memory that stores the on/off status of the call-off key CALL/OFF.

S32 Depending on the state of the call-off key CALL/OFF, the output port P of the microcomputer 80
On/off control of relay RL1 connected to 15 is performed. As a result, the FM modulation circuit 95 and the like are controlled.

S33 An error occurred in data transmission, so the buzzer
Sounds BZ twice to notify the driver that an error has occurred.

34 A key reading error occurred, so the buzzer BZ
sounds three times to notify the driver that an error has occurred.

In Figures 10a, 10b and 10c,
4a and 4b illustrate the operation of the device on the vehicle body shown in FIGS. 4a and 4b; Each operating step will be explained with reference to FIGS. 10a, 10b and 10c.

S51 The contents of the memory are set as initial values, and the status of each output port of the microcomputer 130 is set to the initial level. Through this process, the output port P12 becomes low level L, and output of the FSK signal is prohibited.

S52 Check whether the telephone receiver is off the hook.

S53 The telephone receiver is off the hook, so
Output H to output port HK20 and relay R4
Turn on, output H to output port HK10,
Output L to the output port Audio to set relays R2 and R3 (RL2) to OFF. Now you can use the phone in the same way as a normal car phone.
You can use TEL.

S54 Loads the contents of the memory that stores hands-free call instructions from the steering wheel control board.

S55 Check whether hands-free calling is specified. In the initial state, hands-free calling is not specified, so proceed to step S57, but if the call-off key on the steering wheel operation board
When CALL/OFF is set to on (CALL), hands-free calling is specified and step S56
Proceed to.

S56 Output H to output port HK20 to turn on relay R4, set H to output port HK10, output H to output port Audio to turn on relays R2 and R3 (RL2), and set L to output port P5. output and set relay R1 on. Now the phone TEL and mobile phone
The power of the TRX is turned on, the power of the FM demodulation circuit 17 is turned on, and the amplifier AMP is connected to the audio reception line of the mobile device TRX.

S57 Output L to output port HOLD and relay R5
, outputs L to output port HK20, turns off relay R4, and outputs L to output port HK10.
, outputs L to the output port Audio to turn off relays R2 and R3 (RL2), and outputs T to the output port PS to set relay R1 to OFF. Now the phone TEL, mobile device
The power of the TRX and FM demodulation circuit 170 is turned off, and the telephone TEL and mobile device TRX are connected.

S58 Receive data from steering operation board. This will be explained in detail later.

S59 Determines whether data transmission generated by key operations on the steering operation board is received from the steering operation board.

S60 Determine whether the sent data is a group A key code.

S61 Key code determines whether it is a numeric key, * key, or # key.

S62 key code determines whether the hold key is HOLD.

S63 Key code determines whether it is a clear key CLR.

S64 Clears the memory address counter that stores the key codes of the numeric keys sent so far. In other words, the numeric key input up to that point is canceled.

S65 Determine whether the key code belongs to group B.

S66 Determine whether the key code corresponds to the horn keys HS1 and HS2.

Is the S67 key code a key switch? S68 The horn key has been released, so set the horn to OFF.

S69 The horn key was pressed, so set the horn on.

S70 Check whether the key code is from group C.

S71 Since the key code received as data is not one of groups A, B, or C, it is treated as a data reception error and the buzzer BZ is set to 3.
Ring twice.

S72 Loads the contents of the memory that stores hands-free call instructions from the steering operation board.

S73 Check if the data loaded in S72 specifies a hand-held call.

S74 Loads the contents of the memory that stores instructions by the HOLD key.

S75 Inverts the 1/0 (on/off) of the data loaded in S74 and stores it in the original memory. Therefore, if there is no previous hold instruction,
A predetermined bit of the data is set to "1", that is, a hold designation.

S76 Check whether hold is specified.

S77 Since hold release is specified, output port HOLD and set relay R5 to OFF. Until now, the signal output terminal of the FM demodulation circuit 170 was connected to the transmission audio input terminal T of the mobile device TRX, and it became possible to talk using the microphones MC1 and MC2 on the steering wheel.

Since S78 hold was specified, the output port
Output H to HOLD and set relay R5 to ON. This disconnects the output end of the FM demodulation circuit 170 from the mobile device TRX.

S79 The key code for the numeric key has arrived, so enter that code into the BCD corresponding to the numeric key value.
(Binary Coded Decimal) code and store it in memory at a specified address.

S80 Increments the contents of the counter that specifies the memory address that stores the BCD code of the numeric key.

S8 Checks whether the key code received from the steering operation board indicates operation of the call-off key CALL/OFF.

Determine whether the S82 key code indicates the on (CALL) state of the call-off key.

S83 Since the call-off key has been set to OFF, the contents of the memory that stores the hands-free call designation are set to "0" (hands-free call cancellation).

S84 Since the call-off key has been set to CALL, the contents of the memory that stores the hands-free call designation are set to "1" (hands-free call designation).

S85 Check whether the telephone receiver is disconnected from the telephone.

S86 Outputs H to output port HK20 to turn on relay R4, sets H to output port HK10, outputs H to output port Audio to turn on relays R2 and R3 (RL2), and sets L to output port PS. output and set relay R1 on. Now the phone TEL and mobile phone
The power of the TRX is turned on, the power of the FM demodulation circuit 170 is turned on, and the amplifier AMP is connected to the audio receiving line of the mobile device TRX.

S87 Waits for the relay operating time and the time required for the mobile device to enter the specified operating state after power-on.

S88 Check whether the mobile unit TRX is powered on.

S89 Check whether the vehicle is in a position where it can communicate (whether radio waves can be received). this is,
This is determined by checking whether the TRX output terminal CI is at a level that indicates that a call is possible.

S90 Since the vehicle is in a position where a failure has occurred or communication is not possible, the buzzer BZ will sound twice to notify the driver that an error has occurred.

S91 Set the contents of the memory that stores the hands-free call designation to "0" (hands-free call cancellation).

S92 4-bit BCD of numerical value input using numerical keys
The contents of the memory storing the code are read from the address specified by the numerical pointer (address counter) and loaded into a predetermined register.

S93 Transfer the BCD code obtained in step S92 to the phone.
Convert to the same code as the dial code that generates TEL.

S94 Synchronizing with the pulse signal output from the CP end of the mobile device TRX, output the dial code obtained in S93 sequentially to the DI end.

S95 Increment the value of the numerical pointer once.

S96 Check whether all BCD codes have been read from memory. This is determined by looking at the value of the numerical pointer. If not finished, step
Returning to S92, next read the BCD code from the numerical pointer.

FIG. 11a shows details of the data transmission (transmission) operation of the microcomputer 80. The operation of each step will be explained with reference to FIG. 11a.

S101 8-bit CRC for transmitted data
Generate check character BCC.

S102 Set a predetermined value to a limit counter that limits the number of data transmissions.

S103 Set output port P12 to H and FSK
The bit data of the mark, start bit, transmission data, and BCC code are sequentially set to the output port P11 in synchronization with the clock.

S104 Set L to output port P12 and FSK
Prohibit signal output.

S105 Check whether there is data input from the other party's FSK modulation circuit. If there is no data input, the process advances to step S107.

S106 Check whether there is an acknowledgment ACK0 indicating data reception confirmation sent from the other party.
As will be explained later, when data is transmitted, the receiving side outputs ACK0 to the transmitting side.

S107 Decrement the limit counter value and
It is determined whether the result is 0 or not. If it is not 0, the process returns to S103, and if it is 0, the process proceeds to S113.

S108 Set H to output port P12 again to enable output of FSK signal, mark,
The start bit and each bit of the acknowledge ACK1 indicating confirmation of ACK0 are output continuously in synchronization with the clock.

S109 Set L to output port P12,
Prohibits FSK signal output.

S110 Check whether an FSK signal has arrived from the other party (receiving side). As will be explained later, when the receiving side receives an acknowledgment ACK1 from the transmitting side after outputting an acknowledgment ACK0,
Therefore, the FSK signal is no longer output, but ACK1
If it does not receive it, it will output the FSK signal including ACK0 again. Therefore, from the receiving side here
The arrival of the FSK signal means that data ACK1 from the transmitter has not been received by the receiver.

S111 Since ACK1 has not been received on the receiving side, the value of the limit counter is decremented once and it is checked whether the value is 0 or not. 0
Otherwise, return to step S106 and ACK1 again.
is transmitted, and if it is 0, the process advances to step S113.

S112 Since data transmission is completed within the predetermined number of times set in the limit counter, "OK" is set in the transmission result code.

S113 Even if data is transmitted the predetermined number of times set in the limit counter, data and acknowledgment ACK1 are not transmitted normally.
Set “NG” to the transmission result code.

FIG. 11b shows details of the data receiving operation of the microcomputer 130. The operation of each step will be explained with reference to FIG. 11b.

S121 Check whether the FSK signal has been received, that is, whether data has been input to the input port P13.

S122 Since no data comes to input port P13,
A code corresponding to no data reception is set in the data reception memory.

S123 A predetermined value is set in a limit counter that controls the number of data reception operations for one data transmission.

S124 CRC check character from received data
Generate BCC.

S125 Compare the BCC value of the received data and the BCC value generated in step S124. If the two are equal, it is determined that the data has been received correctly and the process proceeds to step S128; otherwise, the process proceeds to S126.

S126 Since an error has occurred, the limit counter is decremented once and checked to see if the result is 0. If it is not 0, return to S127,
If it is 0, proceed to S134.

S127 Check if there is data input.
If there is received data, proceed to S124, otherwise
Proceed to S126.

S128 Since the data has been received normally, the output port P12 is set to H so that the FSK signal can be output, and the mark, start bit, and acknowledge ACK0 bits are output continuously in synchronization with the clock.

S129 Set L to output port P12,
Prohibits FSK signal output.

P130 Check whether the FSK signal is received on the receiving side.

S131 Check whether the received data is an acknowledgment ACK1 from the transmitting side issued in response to an acknowledgment ACK0 from the receiving side. If it is ACK, proceed to S133, otherwise proceed to S132.

S132 Decrement the contents of the limit counter once and check whether the result is 0. If it is not 0, the process returns to S128, and if it is 0, the process proceeds to S134.

S133 Since data transmission is completed within the predetermined number of times set in the limit counter, "OK" is set in the transmission result code.

S134 Even if data is transmitted the predetermined number of times set in the limit counter, data and acknowledgment ACK1 are not transmitted normally.
Set “NG” to the transmission result code.

In the above embodiments, the case where a telephone is mounted on a vehicle has been described, but the present invention can be implemented in the same way when a radio device such as a commercial radio, an amateur radio, a CB radio, etc. is mounted on a vehicle. . Furthermore, although the embodiment does not include any special equipment other than a buzzer on the steering operation board, for example, as shown in Japanese Patent Application No. 56-188723, a light emitting diode display device is provided on the steering operation board to display various information. Display can be performed on the steering operation board.

As described above, according to the present invention, since the microphone on the steering wheel can be used to make telephone calls, the driver can safely communicate while driving the vehicle without having to drive with one hand.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a steering operation board signal transmission device according to an embodiment of the present invention, and FIG.
The figure is a perspective view showing the vicinity of the steering wheel and driver seat of an automobile equipped with the device shown in Fig. 1, Fig. 2b is a front view showing the steering wheel shown in Fig. 2a, and Fig. 2c is a portion of the steering wheel shown in Fig. 2a. Figures 3a and 3b are side cross-sectional views showing the mounting structure of the device; are block diagrams showing electric circuits provided on the vehicle body side of the device shown in Fig. 1, Fig. 5a, and Fig. 5.
Figure b and Figure 5c are FSK demodulation circuit 1 in Figure 1.
Timing chart showing operation of 10,160,
Fig. 6 is a waveform diagram showing the general signal waveforms of each part of the device in Fig. 1, Fig. 7 is a plan view showing the structure of the data string of the signal (FSK) transmitted by the device in Fig. 1, and Fig. 8 1 is a flowchart showing an outline of the calling operation and the receiving operation when making a telephone call using the device shown in FIG. 1, FIGS. 9a and 9b are flowcharts showing the operation of the microcomputer 80 shown in FIG. 10b and 10c are flowcharts showing the operation of the microcomputer 130 in FIG. 1, FIG. 11a is a flowchart showing the data transmission (transmission) operation of the microcomputer 80 in FIG. 1, and FIG. 11b is a flowchart showing the operation of the microcomputer 80 in FIG. is a flowchart showing the data receiving operation of the microcomputer 130. 1: Driver seat, 2: Telephone (TEL) (second acoustic-electric conversion means), 3: Steering wheel, 31: Operation panel, 38, 41: Support, 39, 42: Gear, 40: Steering shaft, 4
3: Connecting member, 44: Printed circuit board, 70, 12
0: Constant voltage power supply, 80: Microcomputer,
90: Key switch (switch means), 95:
FM modulation circuit (first modulation means), 100: FSK
Modulation circuit (second modulation means), 110: FSK demodulation circuit, 130: Microcomputer (switching control means), 150: FSK modulation circuit, 160: FSK demodulation circuit (second demodulation means), 170: FM demodulation circuit (first demodulation means), 180: branch connection circuit, MC1, MC2: microphone (first acoustic-electric conversion means), SA1, SA2, SB1, SB
2: Slip ring BA1, BA2, BB1, BB
2: Brush, TRX: Mobile device (communication means), DFA:
Differential amplifier, SP: speaker.

Claims (1)

[Scope of Claims] 1. At least one first acoustic-to-electrical conversion means, a first modulation means for modulating a signal from the acoustic-to-electrical conversion means, and a switch installed on or near the steering wheel. and a second modulation means for performing modulation with a signal according to the operation of the switch means,
Steering operation board; equipped on the vehicle body, first demodulating means for demodulating the signal modulated by the first modulating means, second demodulating means for demodulating the signal modulated by the second modulating means, modulated by an audio signal. a communication means for emitting electromagnetic waves, a second acoustic-to-electric conversion means, and a connection switching means for selectively applying the signal from the first demodulation means and the signal from the second acoustic-to-electric conversion means to the communication means. and a switching control means for controlling the connection switching means in accordance with a signal from the second demodulation means; and a transmission means for electrically connecting the steering operation board and the on-vehicle control device; A steering operation board signal transmission device. 2. The steering operation board signal transmission device according to claim 1, wherein the transmission means includes a slip ring and a brush in contact with the slip ring. 3. The steering operation board signal transmission device according to claim 2, wherein a plurality of slip rings and brushes are formed concentrically around the steering shaft. 4. The output end of the first modulation means, the output end of the second modulation means, the input end of the first demodulation means and the input end of the second demodulation means are connected to the first set of slip rings and brushes. , the on-board battery is connected to a second set of slip rings and brushes;
A steering operation board signal transmission device according to claim 3. 5. The second acoustic-to-electrical conversion means is a telephone;
A steering operation board signal transmission device according to claim 1. 6. The steering operation board signal transmission device according to claim 1, wherein the first modulation means is a frequency modulation circuit and the second modulation means is an FSK modulation circuit. 7. The steering operation board includes a third demodulating means, and the on-vehicle control device includes a third modulating means.
6. The steering operation board signal transmission device according to item 5 or 6.