JP3414457B2 - Signal transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission system, and more particularly, to a system in which a part of the system moves, such as an inspection system for articles, which does not come into contact with each other on the rotating side and the fixed side. The present invention relates to a signal transmission system that bidirectionally transmits a digital signal.

[0002]

2. Description of the Related Art Conventionally, a wireless transmission method using a transmission antenna and a reception antenna is known as a method for transmitting signals in a non-contact manner when the signal transmission section and the signal reception section rotate independently of each other. Was used.

However, this wireless transmission system has a problem in that accurate signal transmission is required because it is unavoidable to mix in noise from the outside. Therefore, the inventors of the present invention have proposed a signal transmission device capable of non-contact signal transmission when the signal transmission unit and the signal reception unit relatively rotate. Such a signal transmission device is disclosed in Japanese Patent Application No. 04-07.
No. 0640, Japanese Patent Application No. 04-291181 and the like.

According to the above-mentioned signal transmission device, signal transmission is performed between the transmission side and the reception side in a non-contact manner, so that the signal transmission section and the signal reception section may rotate relative to each other. Even if there is, the signal can be continuously transmitted.

[0005]

In such a system, for example, various control signals are transmitted from the signal transmission section to the rotating section side, and based on this, some inspection or measurement is performed on the rotating section side. In many cases. On the contrary, there is also a demand for performing inspection while sequentially transmitting inspection data, measurement data and the like from the rotating unit side to the signal transmitting unit side. In such a case, without stopping the system itself, that is, without interrupting the rotation operation of the rotating portion, the fixed portion is continuously
If signals can be transmitted between both of the rotating parts to perform inspection, the range of application of the system is expanded.

An object of the present invention is to provide a digital signal such as a control signal between a rotating part side and a fixed part side while maintaining the rotating motion in a system in which a part of the object moves, such as an inspection system for articles. The purpose of the present invention is to provide a signal transmission system for transmitting signals in a stable manner.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a rotating part (40) and a fixing part (10) which rotate relative to each other, the rotating part and the fixed part. Signal transmission unit (M) for transmitting signals to and from the unit
And a fixed signal generator (1) that generates a reference signal (CK).
9), a first encoder (12) that multiplex-encodes a plurality of digital signals to obtain an encoded signal based on the reference signal, and modulates the encoded signal at a first frequency.
And a first modulator (13) for obtaining a _first modulated signal (F ₁ ) and the reference signal are modulated at a second frequency.
A second modulator (2 that acquires a second modulated signal (F ₃ ).
0) and mixing the first and second modulated signals before
The mixer (14) for supplying to the signal transmission section, and the signal transmission
Demodulates the third modulated signal (F ₂ ) input via the transmitter.
And a third demodulator (18) that
A delay circuit that delays the reference signal at the timing of encoding.
Includes a road (21), wherein the rotary unit, the signal distributor for distributing the signals transmitted to said first and second modulation signal from the transmission unit (42), a first that is the distribution first demodulator for the modulation signal demodulating said coded signal (4
And 3), a second demodulator for demodulating the reference signal from the second modulated signal the distribution and (49), said second condensate
Based on the reference signal demodulated by the modulator, a first condensate to produce a digital signal by decoding the coded signal
An encoder (44), and the reference signal is transmitted and received between the fixed unit and the rotating unit via the signal transmission unit. In order to solve the above problems, the invention according to claim 2 provides a rotating portion (4
0) and a fixed part (10), the rotating part and the fixed part
And a signal transmission unit (M) for transmitting signals in a non-contact manner between
In the signal transmission system having, the fixed part is a reference
A reference signal generator (19) for generating a signal (CK),
Based on the reference signal, multiple digital signals are
First encoder for encoding to obtain a first encoded signal
(12) and the first encoded signal at a first frequency
First modulation for modulating to obtain a _first modulated signal (F ₁ ).
(13) and the reference signal is modulated with a second frequency
A second modulator (2 that acquires a second modulated signal (F ₃ ).
0 ) and the first and second modulated signals are mixed to produce
A mixer (14) for supplying to a signal transmission unit,
The rotating unit receives the signal transmitted from the signal transmitting unit as the first signal.
A distributor (42) for distributing the first and second modulated signals,
From the distributed first modulated signal, the first encoded signal
A first demodulator (43) for demodulating the
Second demodulation for demodulating the reference signal from a second modulated signal
And a base demodulated by the second demodulator.
The coded signal is decoded and digitized based on the quasi-signal.
A first decoder (44) for generating a Tal signal,
The reference signal is transferred between the fixed part and the rotary part.
The fixed portion and the rotating portion frequency-select an input signal and transmit it to the signal transmitting portion, and the signal supplied from the signal transmitting portion is transmitted and received through the signal transmitting portion. And a delay circuit (21) for delaying the reference signal for a predetermined time, and a third modulation signal input via the duplexer. (F ₂₎ a third demodulator for demodulating a (18), on the basis of the delayed reference signal, the second to generate a digital signal by decoding the signal demodulated by the third demodulator Decryption
And a multiplexer (17), wherein the rotation unit multiplex-encodes a plurality of digital signals based on the reference signal demodulated by the second demodulator to obtain a second encoded signal.
And a third modulator (46) that modulates the second coded signal at a third frequency, and the predetermined time is The time (t ₁ ) until the reference signal is input from the reference signal generator of the fixed unit to the second encoder of the rotating unit, and the time from the second encoder of the rotating unit. It is a total time of a time (t ₂ ) until the fixed unit is input to the second decryptor .

[0008]

According to the present invention, a plurality of digital signals such as control signals and a reference signal for multiplexing the digital signals are used by using a signal transmission section that transmits signals while rotating in a non-contact manner. Since they are independently modulated and transmitted, it is possible to efficiently transmit digital signals such as control signals in both directions on the rotating side and the fixed side in a system in which some of them rotate. Become.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a signal transmission device according to an embodiment of the present invention.

In FIG. 1, the signal transmission device is roughly composed of a fixed portion 10, a rotating portion 40, and a matching unit M. The mutual positional relationship between the fixed portion 10 and the rotating portion 40 is shown in FIG. The fixed portion 10 is fixed by a member (not shown) and is immobile regardless of the rotation of the rotary shaft 30. On the other hand, the rotating portion 40 is fixed to the rotating shaft 30 and rotates in the direction of the arrow in the figure as the rotating shaft 30 rotates. With such a configuration, signals are transmitted between the fixed part 10 and the rotating part 40 while mutually rotating. Each circuit shown in FIG. 1 is incorporated in each unit of the rotating unit 10 and the fixed unit 40 shown in FIG.

Next, the structures of the fixed portion 10 and the rotating portion 40 will be described with reference to FIG. Fixed part 10
Are isolation amplifiers 11 and 16 and encoder 1
2, decoder 17, FM modulators 13, 20, FM demodulator 18, clock generator 19, delay circuit 21, mixer 1
4, and the duplexer 15 are comprised.
Further, the rotating unit 40 includes the duplexer 41 and the distributor 4
2, FM demodulators 43 and 49, FM modulator 46, decoder 44, encoder 47, isolation amplifier 45,
It is configured with 48. A signal is transmitted between the fixed portion 10 side and the rotating portion 40 side by the matching unit M.

An example of the matching unit M is shown in FIG.
And (B). In FIG. 3A, the matching unit M is provided on the fixed portion 10 and the rotating portion 40.
The fixed element 10 has a signal element E ₁ and the rotary element 4 has
A signal element E ₂ is provided at 0. As shown in FIG. 2, the fixed portion 10 is fixed, and the rotating portion 40 rotates in the direction of the arrow as the rotating shaft 30 rotates. Signals from the duplexers 15 and 41 in the rotating portion 10 and the fixed portion 40 are supplied to signal elements E ₁ and E ₂ by lead wires (not shown).
Is supplied to.

During signal transmission, the rotation of the rotary shaft 30 causes the signal element E ₁ and the signal element E _{2 to} rotate while facing each other while maintaining a predetermined distance therebetween, so that the two signals can contact each other without contacting each other. Is transmitted.
Details of such a matching unit are described in Japanese Patent Application No. 04-070640.

Further, FIG. 3B shows a matching unit M
Another example of The matching unit M is also provided in the fixed portion 10 and the rotating portion 40. The fixed portion 10 and the rotating portion 40 are provided with signal elements E ₃ and E ₄ , respectively. This matching unit M is different from the case of FIG. 3A in that each signal element is formed of a spiral conductor in order to average the propagation intensity of the transmitted signal and realize stable transmission. , Fixed part 10 and rotating part 40
The operation of is similar to the case of FIG. That is, while the rotating unit 40 rotates in the direction shown in the drawing, the signal is transmitted between both signal elements in a non-contact manner. For details of such a matching unit, refer to Japanese Patent Application No. 04-29118.
No. 1 is described.

Next, the signal transmission operation will be described.
In the following description, a case where digital signals for four channels as control signals are mutually transmitted will be described.
First, the transmission from the fixed unit 10 to the rotating unit 40 will be described.

The data D ₁₁ -D ₁₄ are supplied to the unit of the fixing portion 10 shown in FIG. 2 via a connector (not shown),
It is input to the isolation amplifier 11. Each data D
_11- D ₁₄ is input at the TTL / CMOS level, and the isolation amplifier 11 separates each data, amplifies it to a predetermined level, and inputs it to the encoder 12. on the other hand,
The clock generator 19 generates a clock signal CK having a predetermined frequency.
Is generated and input to the encoder 12. Encoder 12
Is the data D ₁₁ − based on the input clock signal.
D ₁₄ is time-division multiplexed. This state is shown in FIG. As shown in FIG. 4, the data D _{11 to} D ₁₄ are sampled with the clock CK as a reference, and the value thereof is generated as the data D ₁ including the data of 4 channels. This data D
₁ is input to the FM modulator 13, and the carrier frequency f ₁
Is frequency-modulated by and is input to the mixer 14 as the signal F ₁ .

On the other hand, the clock signal CK generated by the clock generator 19 is input to the FM modulator 20, frequency-modulated at the carrier frequency f ₃ and output as the signal F ₃ . The signals F ₁ and F ₃ are mixed by the mixer 14 and input to the duplexer 15. The duplexer is a circuit for transmitting signals of a plurality of frequencies simultaneously and independently in both directions, and includes a signal F ₁ and a signal F ₃ input from the mixer 14 and a signal transmitted from the rotating unit side. of F _2, selects and inputs the signal F ₁ and the signal F ₃ in frequency to the matching unit M. In the matching unit M, the signal F is contactlessly contacted while the rotating portion 40 is still rotating.
₁ and the signal F ₃ are transmitted to the rotating unit 40 side.

Fixed part 10 through matching unit M
The signal transmitted from the side is input to the duplexer 41.
Be done. The duplexer 41 uses the signal F₁And signal F₃To
Select and send to distributor 42. The distributor 42 has been input
Signal to signal F₁And signal F₃Split into and FM
Send to demodulators 43 and 49. The FM demodulator 49 receives the signal F
₃To demodulate the clock signal CK and input it to the decoder 44.
Force Further, the FM demodulator 43 outputs the signal F₁Data from
D₁Is demodulated and input to the decoder 44. Decoder 44
Is time-division multiplexed based on the input clock signal CK.
Data D ₁To 4 channels of data D₁₁-D₁₄
Is generated and input to the isolation amplifier 45. A
The isolation amplifier 45 uses each data D₁₁-D₁₄Where
Amplify to a constant level and output. According to the above flow, 4
Digital data D for channel data₁₁-D₁₄But,
It is transmitted to the rotating unit 40 side.

Next, data transmission from the rotating portion 40 side to the fixed portion 10 side will be described. The digital data D ₂₁ -D ₂₄ to be transmitted from the rotating unit 40 side is amplified to a predetermined level by the isolation amplifier 48 and input to the encoder 47. The encoder 47 time-division-multiplexes data D ₂₁ -D ₂₄ for four channels by the same operation as the encoder 12 on the side of the fixed unit 10 described above, and outputs the data D ₂₁ -D _24.
2 is input to the FM modulator 46. Encoding in the encoder 47 is performed based on the clock signal CK demodulated by the FM demodulator 49. FM modulator 46
Frequency-modulates the data D ₂ with the carrier frequency f ₂ ,
The signal F ₂ is input to the duplexer 41. The duplexer 41 transmits the signal F ₂ to the fixed unit 10 side via the matching unit.

On the fixed portion 10 side, the matching unit M
Only the signal F ₂ is input to the FM demodulator 18 from the signal received by the duplexer 15. FM demodulator 18
Demodulates the data D ₂ from the signal F _2, and sends to the decoder 17. On the other hand, the clock signal CK generated by the clock generator 19 is input to the decoder 17 after being delayed by the delay circuit 21 for a predetermined time. Here, the delay circuit 21 is provided for time alignment between the data decoded by the decoder 17 and the clock signal used for this decoding. That is, the clock signal CK generated by the clock generator 19 is transmitted through the matching unit M to the rotation unit 4
It is input to the encoder 47 on the 0 side. If the time until the clock signal is input to the encoder 47 is t ₁ , the signal from the encoder 47 is the clock generator 19
It is decoded with reference to the clock signal sent by t ₁ from the clock generated in. Then, the decoded data D ₂ is transmitted from the rotating unit 40 to the fixed unit 10 side by the reverse route and is input to the decoder 17. If the time required during this period is t ₂ , the clock signal CK generated by the clock generator 17 is (t ₁
It is necessary to decode with a clock signal delayed by + t ₂ ). Therefore, the clock signal is delayed by the delay circuit 21 and then supplied to the decoder 17.

Data D ₂₁ decoded by the decoder 17
-D ₂₄ is amplified to a predetermined level by the isolation amplifier 16 and output. As described above, it is possible to bidirectionally transmit data between the fixed unit 10 and the rotating unit 40 while rotating the rotating unit 40.

As described above, in the present invention,
A multiplexed data signal and a clock signal which is a reference signal for multiplexing are modulated at different frequencies, and these are mixed and transmitted. Generally, when signals of a plurality of channels are multiplexed and transmitted as one signal, it is common to insert a reference signal for synchronization control between each data signal. The amount of data to be transmitted is reduced by the amount of the reference signal. In this respect, according to the present invention, the data signal not including the reference signal and the clock signal as the reference signal are transmitted independently, so that even if the number of data to be transmitted is increased, only one clock signal is transmitted. Sufficient, efficient data transmission becomes possible.

In the above description, the binary signal CK as shown in FIG. 4 is used as the clock signal. However, as shown as CK ₁ in the figure, it is a ternary signal and any data If you change the signal level in the part corresponding to, it becomes possible to control the synchronization of the clock signal itself,
The inspection or the like can be performed while sequentially correcting the delay time.

Further, in the above description, the case where the clock generator or the like for generating the reference signal for encoding is provided on the fixed portion side is described. However, these are provided on the rotating portion side and the fixed portion is provided. It is also possible to reverse the configuration of the side and the rotating portion side.

[0025]

As described above, according to the present invention,
Using a signal transmission unit that transmits signals while rotating in a non-contact manner, a plurality of digital signals such as control signals and a reference signal for multiplexing the digital signals are independently modulated and transmitted. Therefore, in a system in which a part rotates, it becomes possible to efficiently transmit a digital signal such as a control signal bidirectionally on the rotating side and the fixed side.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a signal transmission device that is an embodiment of the present invention.

FIG. 2 is an external configuration diagram of a matching unit.

FIG. 3 is a diagram showing an example of a matching unit.

FIG. 4 is a diagram showing a method of multiplexing digital data.

[Explanation of symbols]

10 ... Fixed part 11, 16, 45, 48 ... Isolation amplifier 12, 47 ... Encoder 13, 20, 46 ... FM modulator 18, 43, 49 ... FM demodulator 14 ... Mixer 15, 41 ... Duplexer 17, 44 Decoder 19 Clock generator 21 Delay circuit 30 Rotation axes E _{1 to} E ₄ Signal element M Matching unit

Claims (2)

(57) [Claims] 1. A rotating part and a fixed part which rotate relative to each other,
In a signal transmission system having a signal transmission unit that transmits a signal in a non-contact manner between the rotating unit and the fixed unit, the fixed unit includes a reference signal generator that generates a reference signal, and a reference signal generator that generates a reference signal. A first encoder that multiplex-encodes a plurality of digital signals to obtain an encoded signal, and a first modulator that modulates the encoded signal at a first frequency.
A first modulator for obtaining a signal, the reference signal, the second modulated signal by modulating a second frequency
Second and modulator, a mixer supplied to the signal transmitting unit by mixing the first and second modulated signals, a third modulation signal input through the signal transmission unit that acquires No. Restore
The third demodulator that adjusts and the reference at the timing of decoding the demodulated signal.
It includes a delay circuit for delaying a signal, wherein the rotating unit includes a distributor for distributing the signals transmitted from the signal transmitting unit to said first and second modulated signals, the distributed first a first demodulator for demodulating the encoded signal from the modulated signal, a second demodulator for demodulating the reference signal from the second modulated signal the distribution, demodulated by said second demodulator A first decoder that decodes the coded signal based on a reference signal to generate a digital signal , and the reference signal is transmitted between the fixed unit and the rotating unit. A signal transmission system, characterized in that the signal is transmitted and received via the. 2. A rotating part and a fixed part which rotate relative to each other,
To transmit a signal in a non-contact between the said and the rotating portion solid tough
In the signal transmission system including a signal transmission unit , the fixed unit multiplexes a plurality of digital signals based on the reference signal generator that generates a reference signal and the reference signal.
A first encoder for encoding to obtain a first encoded signal
And modulating the first encoded signal at a first frequency
A first modulator that obtains a modulated signal of, and a second modulated signal by modulating the reference signal with a second frequency.
A second modulator for obtaining the signal transmission by mixing the first and second modulated signals.
And a mixer for supplying the signal to the unit, and the rotating unit is configured to forward the signal transmitted from the signal transmitting unit.
A distributor for distributing the first and second modulated signals, and the first encoded signal from the distributed first modulated signal.
First demodulator for demodulating the signal, and demodulating the reference signal from the distributed second modulated signal
A second demodulator and a reference signal demodulated by the second demodulator
To decode the first encoded signal to obtain a digital signal
A first decoder for generating the signal between the fixed unit and the rotating unit.
Are transmitted and received through a No. transmitting portion, the fixed portion and the rotating portion is configured to transmit to the signal transmission unit a signal input selected in frequency, frequency specific signals supplied from the signal transmission unit A fixed circuit for delaying the reference signal for a predetermined time, and a third demodulator for demodulating a third modulated signal input via the duplexer. The third demodulator based on the delayed reference signal
A second decoder that decodes the signal demodulated by to generate a digital signal, and the rotation unit includes a plurality of digital signals based on the reference signal demodulated by the second demodulator. The signal is multi-coded into a second code
A second encoder that obtains a coded signal; and a third modulator that modulates the second coded signal at a third frequency, and for the predetermined time, the reference signal is fixed. Time from the reference signal generator of the rotating unit to the second encoder of the rotating unit, and the second decoding of the fixed unit from the second encoder of the rotating unit . A signal transmission system characterized in that it is a total time of a time until it is input to the device and a time.