JPH0445505A - Rotation coupler - Google Patents

Abstract

PURPOSE:To compensate the delay time variation of a high frequency signal that is transmitted between a rotary part and a fixed part for stabilizing the transmission characteristics of a transmission signal from the rotary part in operation by detecting the position of a rotation angle, followed by controlling the amount of delay of a variable delay means based on the detected rotation angle position. CONSTITUTION:When a modulation output signal obtained by modulating the high frequency signal using a regenerating video signal is supplied to the signal input terminal of the first microstrip 1 at the side of the rotary part 2 from the modulator 7, the modulation signal is transmitted to the terminal side of the first microstrip 1 and is partly transmitted to the second microstrip 3 on the side of the fixed part 4 opposite to the rotary part 2. Although this output signal is accompanied by a delay time variation that is accompanied by the rotation of the rotary part, a variable delay circuit 6 installed at the output terminal compensates this variation. The circuit 6 variably controls an amount of delay in conformity with the position of a rotation angle of the rotary part with the aid of a control part 18 that carries out a control operation based on a detecting signal from a rotation angle position detecting portion 5. The output from the circuit 6 is demodulated by means of a demodulator 12.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention provides an i! The present invention relates to a rotary coupler that transmits and receives high-frequency signals between the rotating part and the fixed part by electromagnetic coupling, and is applied to, for example, a rotating magnetic head type video tape recorder.

B. Summary of the Invention The present invention includes a first microstrip arranged on a first circumference and a conductor layer provided in parallel with the first microstrip via a dielectric layer. 1st
a rotating part having a microstrip line having a rotation center around the center of the first circumference, and a position close to and facing the first microstrip on a second circumference centering on the rotation center; a fixed part having a second microstrip line constituted by a second microstrip arranged in the second microstrip line and a conductor layer provided in parallel with the second microstrip via a dielectric layer; and an input circuit connected to one of the second microstrip lines for inputting a high frequency signal, and an input circuit connected to the other of the first and second microstrip lines and inputted by the input circuit. and an output circuit for extracting a high frequency signal, and the length of the NM coupling part where the first microstrip and the second microstrip are electromagnetically coupled is determined so that the high frequency signal propagates through the magnetic coupling part. The distance between the rotating part and the fixed part is set at an odd number multiple of approximately 1/4 of the wavelength of the signal, and the electromagnetic coupling part of the first microstrip and the second microstrip is coupled by a length of 1m. In a rotary coupler configured to transmit and receive high-frequency signals at This is compensated by a variable delay means whose delay amount is variably controlled depending on the position. Conventional technology Generally, in a rotating magnetic head type video tape recorder,
A rotary transformer is widely used to send and receive recording video signals and playback video signals to and from a rotating magnetic head provided in a rotating section. Conventionally, in rotary transformers that transmit signals using magnetic coupling between coils, the signal band that can be transmitted is narrow due to the influence of coil inductance and stray capacitance, and the limit is about 60 MHz.

In recent years, with the development of digital VTRs, data recorders, high-definition televisions, etc., the signals handled have become wider and wider.
A rotating coupler with broadband transmission characteristics is needed.

For example, as disclosed in Japanese Patent Publication No. 64-9763, the applicant formed a microstrip line that acts as a directional coupler on the opposing surfaces of a rotating part and a fixed part to transmit broadband signals. We have previously proposed a microstrip line type rotary coupler that achieves this.

The microstripe line type rotary coupler disclosed in the above-mentioned Japanese Patent Publication No. 64-9763 includes a first microstrip arranged on a first circumference, a dielectric layer between the first microstrip, and a dielectric layer. a first microstrip line configured with a conductor layer provided in parallel through a rotating part with the center of the first circumference as the center of rotation; a second microstrip disposed close to and facing the first microstrip on the circumference of the second microstrip; and a conductor layer provided in parallel with the second microstrip via a dielectric layer. a fixed part having a second microstrip line; an input circuit connected to one of the first and second microstrip lines for inputting a high frequency signal; and an output circuit that is connected to the other of the strip lines and takes out the high frequency signal inputted by the input circuit, and the first microstrip and the second microstrip are coupled in an NH3 manner. The length of the electromagnetic coupling portion is an odd multiple of approximately 1/4 of the wavelength of the high frequency signal propagating through the electromagnetic coupling portion, and the length of the 1Mi coupling portion between the first microstrip and the second microstrip is High frequency signals are exchanged between the rotating part and the fixed part by magnetic coupling.

In this rotary coupler, for example, as shown in FIG. 5, the first microstrip (31) on the rotating part side has one end serving as a signal input end for a high frequency signal, and the other end serving as a non-reflection terminating resistor (31). 32). Further, one end of the second microstrip (32) on the fixed part side is used as a signal output end for a high frequency signal, and the other end is terminated by a non-reflection terminating resistor (34). The length of the microstrips (31) and (33) facing each other, that is, the length of the second microstrip (33) on the fixed part side is the signal wavelength λ of the high frequency signal.
Odd multiple of 174 wavelengths, that is (2n+1)・λ/4
is set to . The second microstrip (33) on the fixed part side is electromagnetically coupled with the first microstrip (31) on the rotating part side so that it functions as a directional coupler for transmitting high frequency signals. It has become.

D. Problems to be Solved by the Invention However, in the rotary coupler having the above-mentioned configuration that was previously proposed by the applicant, there is a problem in that the delay characteristics of the transmission signal fluctuate as the rotating part rotates. . That is, in the microstrip line type rotary coupler, the first microstrip (31) on the rotating section side and the second microstrip (33) on the rotating section side are coupled in an R:LMi manner to connect the rotating section. High frequency signals are exchanged with the fixed part, and as the rotating part rotates, as shown in FIG. 6, each of the microstrips (31),
(33) is electromagnetically coupled to W [the coupling portion also moves, and the first microstrip (31) on the rotating part side
Since the relative distance HD between the signal input end of the microstrip and the signal output end of the second microstrip (33) on the fixed part side changes with the rotation of the rotating part, the transmission signal changes as the rotating part rotates. The delay characteristics vary as shown in FIG.

Therefore, in view of the above-mentioned problems with the microstri-two-brine type rotary coupler, the present invention aims to eliminate fluctuations in the delay characteristics of the transmission signal due to the rotation of the rotating part and to obtain stable transmission characteristics. The present invention aims to provide a microstrip line type rotary coupler that has a function of compensating for variations in delay characteristics of transmission signals due to rotation of a rotating part.

E Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a first microstrip arranged on a first circumference and a dielectric layer interposed between the first microstrip and the first microstrip. a first microstrip line configured with a conductor layer provided in parallel with each other; Arranged at a position close to and facing the first microstrip on the circumference! a fixed part having a second microstrip line constituted by a second microstrip and a conductor layer provided in parallel with the second microstrip through a dielectric layer; an input circuit for inputting a tongue-and-groove high-frequency signal connected to one of the second microstrip line and the second microstrip line; an output circuit for extracting a high frequency signal, and the first microstrip and the second microstrip.
The length of the electromagnetic coupling portion where the first microstrip and the first microstrip are coupled is set to be an odd multiple of the wavelength of the high frequency signal propagating through the electromagnetic coupling portion ]/4, and the length of the electromagnetic coupling portion where the first microstrip and the In a rotary coupler that transmits and receives high-frequency signals between the rotating part and the fixed part by electromagnetic coupling at the electromagnetic coupling part with the second microstrip, the rotational angular position of the rotating part is detected. The input circuit or the output circuit includes a rotational angular position detection means for detecting a rotational angular position, and a variable delay means for variably controlling a delay amount according to a rotational angular position of the rotating part based on a detection output from the rotational angular position detection means. The variable delay means is provided in at least one of the above, and the variable delay means compensates for delay time fluctuations caused by rotation of the rotating section of the high frequency signal transmitted and received between the rotating section and the fixed section. It is.

F Function In the rotary coupler according to the present invention, the rotational angular position of the rotating part is detected by the rotational angular position detection means, and the delay amount of the variable delay means is variably controlled according to the rotational angular position of the rotating part. Compensating for delay time variations in high frequency signals transmitted and received between the rotating part and the fixed part due to rotation of the rotating part.

G. Example Hereinafter, an example of the rotary coupler according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a rotary coupler according to the present invention used in a rotary magnetic head device of a video tape recorder, and the rotary coupler shown in FIG. a rotating part (2) having a first microstrip line constituted by a first microstrip (1) arranged on the first circumference (C1) with the rotation center (S) at the center of rotation; A second microstrip (3) formed of a second microstrip (3) disposed at a position close to and facing the first microstrip (1) on a second circumference (Cz) centered on the rotation center (S). A fixed part (4) having two microstrip lines, a rotational angular position detection part (5) that detects the rotational angular position of the rotating part (2), and a detection output from this rotational angular position detection part (5). A variable delay circuit (6) whose delay amount is variably controlled in accordance with the rotational angular position of the rotating section (2) is provided.

First microstrip (1) on the rotating part (2) side
One end is connected to the modulator (7) as a signal input end, and the other end is terminated to a non-reflection terminating resistor (8).

The modulator (7) is supplied with a reproduced video signal from the rotating magnetic head (9) via a regenerative amplifier (10), and is also supplied with a high frequency oscillator (11) such as -frequency f,
A high frequency signal of about 10 GHz is supplied. This modulator (7) modulates the high frequency signal with the reproduced video signal and supplies the modulated output signal to the signal input end of the first microstrip (1).

Further, one end of the second microstrip (3) on the fixed part (4) side is connected as a signal output end to the demodulator (12) via the variable delay circuit (6), and The other end is terminated by a non-reflective terminating resistor (13).

Furthermore, in this rotary coupler, the first circumference (C
1) is the signal wavelength λ of the high frequency signal. An integer n times n, that is, n·λ. The circumferential length L0 is approximately one round on this first circumference (C1).
A microstrip (1) is formed. Also,
The first and second microstrips (1) and (3)
) is the length of the NTa coupling portion facing each other, that is, the length of the second microstrip (3) on the fixed part (2) side is equal to the signal wavelength λ of the high frequency signal. An odd multiple of 1/4 wavelength, that is, (2n+1)·λ. /4 is set.

Further, the rotating part (2) and the fixed part (3) are each formed into a cylindrical shape using a dielectric material, as shown in the second section. The inner peripheral surface of the rotating part (2) is entirely covered with a conductor Ji (14), and
The conductor layer (15) covers the entire outer peripheral surface of the fixed part (4).
), and the rotating part (2) and the fixed part (4) are further provided with the first and second parts on respective circumferential surfaces facing each other.
Microstri 7b (1).

(3 microstrips are arranged so as to face each other. The first microstrip (1 microstrip) on the rotating part (2) side
) forms a first microstrip line by facing the conductor layer (14) via the dielectric layer made of the dielectric material forming the rotating part (2). Further, the second microstrip (3) on the side of the fixing part (4) is connected to the conductor layer (15) through the dielectric layer made of the dielectric material forming the fixing part (4).
By facing each other, a second microstrip line is formed. Further, coaxial cables (16) and (17) are respectively led out from one end of the first and second microstrips (IL (3)) as lead wires for external connection.

Further, the variable delay circuit (6) is controlled by a control section (18) that performs a control operation based on the detection output from the rotation angle position detection section (5) according to the rotation angle position of the rotation section (2). , the amount of delay is variably controlled as shown by the solid line in FIG.

Thereby, the variable delay circuit (6) is connected to the rotating section (
2) and the fixed part (4) due to the rotation of the rotating part (2), as shown by the broken line in FIG. 3, is compensated for.

The variable delay circuit (6) may be a variable capacitor (6) using a variable capacitance diode, as shown in FIG.
Bridge circuit (20) consisting of a coil (21) and a coil (22)
A multi-stage cascade connection is used. The variable delay circuit (6) shown in FIG. 4 has a delay time of 1 stage of the bridge circuit (20), where fl is the upper limit frequency of use.
, and by varying the capacitance of the variable capacitor (21), it is possible to perform variable control of the upper limit frequency f, that is, variable control of the delay time.

Here, the transmission signal, that is, the high frequency signal transmitted between the rotating part (2) and the fixed part (4) has a delay time variation of 1/2f with respect to the frequency f0 of the high frequency signal. This occurs with the rotation of the rotating part (2), so the variable delay circuit (6) has f+ = f.

By setting the value to 2fa, it is possible to compensate for a delay time variation of 1/2fe. The frequency band used by the rotary coupler is f0±0.51. i.e. f0/2~3
f, /2, so in order to compensate over the entire band by the variable delay circuit (6), the bridge circuit (20
) can be connected in cascade in three stages.

The rotation angle displacement 1 detection section (5) includes an FC pulse signal generator that outputs an FG pulse signal for each unit rotation angle of the rotation section (2), and a FC pulse signal generator that outputs position data for each unit rotation angle. A so-called rotary encoder or the like can be used.

In the rotary coupler having such a configuration, a modulated output signal obtained by modulating the high frequency signal with the sleeping video signal is transmitted from the modulator (7) to the first microstrip (1) on the rotating section (2) side. This modulated output signal is supplied to the signal input terminal of the first microstrip (1).
is propagated in one direction toward the terminal end of the microstrip (1), and a part of the fixed portion (
4) is propagated to the second microstrip (3) on the side. Note that the signal that is not propagated from the first microstrip (1) to the second microstrip (3) is propagated in one direction toward the terminal end of the first microstrip (1). It is absorbed by the non-reflection terminating resistor (8).

The modulated output signal obtained at the signal output end of the second microstrip (3) on the fixed part (4) side is accompanied by delay time fluctuations due to the rotation of the rotating part (2). The variable delay circuit (6) provided at the signal output end of the second microstrip (3) compensates for this delay time variation. This second microstrip (3
) is supplied to the demodulator (12) with the delay time variation compensated for by the variable delay circuit (6), and the modulated output signal obtained at the signal output terminal of the demodulator (J
2).

Note that the present invention is not limited only to the above-mentioned embodiments; for example, in the above-mentioned embodiments, the second
A variable delay circuit (6) was provided at the signal output end of the microstrip (3) to compensate for delay time fluctuations accompanying the rotation of the rotating section (2). It may be provided at the signal input end of the first microstrip (1) on the 2) side, and the present invention can also be applied to a rotary coupler having a disc-shaped rotating part and a fixed part.

H Effects of the Invention In the rotary coupler according to the present invention, the rotational angular position of the rotating part is detected by the rotational angular position detection means, and the delay amount of the variable delay means is variably controlled in accordance with the rotational angular position of the rotating part. As a result, it is possible to compensate for the delay time fluctuation of the high frequency signal transmitted and received between the rotating part and the fixed part due to the rotation of the rotating part. By eliminating this, stable transmission characteristics can be obtained.

[Brief explanation of the drawing]

Figure 1 shows the rotating magnetism of a video tape recorder. FIG. 2 is a partial cross-sectional external perspective view of the rotary coupler, and FIG. 3 is an operation of the variable delay circuit in the rotary coupler. FIG. 4 is a circuit diagram showing a specific example of the configuration of the variable delay circuit. FIG. 5 is a diagram schematically showing the configuration of a conventional rotary coupler, and FIG.
Figure 7 is a diagram showing the relative positional relationship between the microstrip and the second microstrip on the fixed part side, and Figure 7 is a characteristic diagram showing the delay time fluctuation of the transmission signal that occurs with the rotation of the rotating part in a rotary coupler. be. (1) (3) ・・・・・・ (2)・・・・・・・・・・ (4)・・・・・・・・・・ (5) ・・・・・・・・・・(6)・・・・・・・・・(8),(13)・・・・・・(14),(15)・・・・・・Microstrip rotating part Fixed part Rotation angle position detection part Variable delay Circuit non-reflective termination anti-conductor layer patent

Claims (1)

[Scope of Claims] A first microstrip consisting of a first microstrip arranged on a first circumference and a conductor layer provided in parallel with the first microstrip through a dielectric layer. a rotating part having a microstrip line and having a rotation center around the center of the first circumference; and a second circumference having a rotation center around the rotation center at a position close to and facing the first microstrip. a fixed part having a second microstrip line constituted by a second microstrip arranged therein and a conductor layer provided in parallel with the second microstrip through a dielectric layer; an input circuit connected to one of the second microstrip lines for inputting a high frequency signal; and an input circuit connected to the other of the first and second microstrip lines and inputted by the input circuit; and an output circuit for extracting a signal, and the length of the electromagnetic coupling portion where the first microstrip and the second microstrip are electromagnetically coupled is the length of the electromagnetic coupling portion of the high frequency signal propagating through the electromagnetic coupling portion. The electromagnetic coupling in the electromagnetic coupling portion between the first microstrip and the second microstrip causes a high frequency signal to be transmitted between the rotating part and the fixed part. In the rotary coupler configured to perform transmission and reception, a rotational angular position detection means for detecting the rotational angular position of the rotating part is provided, and the rotational angular position of the rotating part is determined based on the detection output from the rotational angular position detection means. A variable delay means whose delay amount is variably controlled according to the rotation of the rotating section is provided in at least one of the input circuit or the output circuit, and the high frequency signal is transmitted and received between the rotating section and the fixed section as the rotating section rotates. A rotary coupler characterized in that delay time fluctuations are compensated for by the variable delay means.