JPS59125067A - Transmitting system of speed and direction information - Google Patents

Abstract

PURPOSE:To simplify a transmission line by transmitting both a speed information and a direction information by a single pulse train. CONSTITUTION:When an output of the first detecting element 8 is supplied to a D-input terminal of a D-type flip-flop 14, and an output of the second detecting element 9 is supplied to a clock input terminal CK of the D-type flip-flop 14, as for the D-type flip-flop 14, a Q output of the flip-flop 14 and a Q' output become a low level and a high level, respectively, in the reverse direction running period, and on the other hand, the Q output of the flip-flop 14 and the Q' output become a high level and a low level, respectively, in the forward direction running period. Therefore, a signal containing a direction information is obtained from the flip-flop 14. A single pulse train containing both a speed information and the direction information is transmitted to a receiving circuit 21 by a single transmission line 20. An output stage of a delaying circuit 22 obtains a delay output through a waveform shaping circuit 23. The D-input terminal of a D-type flip-flop 24 is coupled with the transmission line 20 through an input terminal 21, and its clock input terminal CK is coupled with the waveform shaping circuit 23.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a speed and direction information transmission system suitable for V 1'R (video tape recorder), a remote control for a tape recorder, and ν signal transmission.

BACKGROUND ART One conventional method for detecting the amount or position of tape in a VTR or tape recorder is as shown in FIG.
A speed detector (2) and a rotation direction detector (
3) Up/down counter (6) for speed signal and direction signal using two transmission lines + 41 F57.
There is a method in which the speed signal (number of laps) is counted in an up-counting operation when the vehicle is traveling in the forward direction, and it is counted down when the vehicle is traveling in the reverse direction. In addition, the μ port shown in Fig. 2 (the N and S poles of the magnet disc (7) connected to the rotating body)
The first and second magnetic detection elements +81 (9) are provided so that outputs can be obtained corresponding to the poles, and a pair of detection probes t81 (91) are arranged at an angular interval of 45 degrees. The outputs of the detection probes t81 and t91 are waveform-shaped as shown in FIG.
The period of the pulse (ie, the repetition frequency) in Fig. 3 is input to the tape counter as speed information, and the rotation direction is detected based on the phase relationship with the waveform (Al and waveform CB) in Fig. 3. There is a method to control up/down counters. However, even if Isukyu's method is adopted,
Two transmission paths are now required to transmit speed information and direction information. Of course, if a single frequency multiplexing transmission system is adopted, a plurality of signals can be transmitted through j transmission paths, but the configuration of the transmission device will inevitably become complicated.

OBJECTS OF THE INVENTION An object of the present invention is to provide a transmission system that can relatively easily transmit both speed information and direction information over a single transmission path.

Structure of the Invention To achieve the above object, the present invention provides a method for transmitting moving speed information and moving direction information of an object (for example, a tape).
The generation period of the pulse is made to correspond to the speed information, the polarity of the pulse is made to correspond to the direction information, and the width of the bulge is set to be smaller than ]/2 of the period of the pulse at the maximum moving speed of the object. The present invention relates to a speed and direction information transmission method characterized by transmitting a single pulse train.

Effects of the Invention According to the above invention, since both speed information and direction information are transmitted by a single pulse train, the transmission path can be simplified.

Embodiment Next, a tape position or tape prize counting device of a magnetic tape recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5. In FIG. 4, 1b) is a pair of reels on which the magnetic tape 121 runs. (7) is a magnetic disc for detecting the running speed and running direction of the °C tape based on the rotation of the reel [1a], and in this embodiment has a toe pole and an south pole at 90 degree intervals. 181 (93 is the second) and second magnetic detection element, which are arranged on the outer peripheral surface of 1 circle & (7J so that they have an angular interval of about 45 mm.
There is a waveform shaping circuit in the battery. Therefore, as shown in FIG. 5 (Al
The waveform of is output from the detection element (8), and the waveform of
The waveform shown in FIG. 5 (■) is output from this.

(II is a transmission circuit, and a pair of detection elements (8119)
Based on the waveform of the wJs diagram (false) [F]) obtained from the monostable multi-bi break shown in the D-type flip-flop Q41.MWV, to form a single transmit pulse train shown in Figure 5 (II). Q51. Two AND games)
(lblCI7), one OR gate, and an output terminal (191z').

The transmission line 18 (4) is a single transmission path, and is used to send the output signal of the transmitting circuit (131) to the input terminal (21a) of the receiving circuit CD. However, it is also possible to transmit wirelessly by connecting the transmitter and the receiver.The receiving circuit 11JII is a circuit that performs the necessary counting based on the pulse train shown in FIG. Circuit 7z and the waveform shaping circuit.

As a D type flip-flop (to) and a tape counter ℃
It has an up/down counter (c).

Next, the operation of the circuit shown in FIG. 4 will be explained with reference to the waveforms shown in FIG. Now, the tape (12+
is running in the opposite direction, the waveform (Al (B
As shown in Figure 1, a pulse with a duty ratio of 50% is generated at a period (frequency) according to the speed, and the output waveform of the second detection element +91 has 6 waves (the pulse of Al leads the waveform by 90 degrees than the pulse of the second detection element +91). On the other hand, when traveling in the forward direction, t7
As shown below, the waveform (Al waveform B) is advanced by 90 degrees.

The output of the first detection element (8) is a D-type flip 70-tube I
The output of the second detection element (9) is supplied to the clock input terminal [CK] of the Da flip-flop circle.
When supplied to CB, the D-type flip-flop circle is
What is the level of the waveform pile at the leading edge (rise) of the + pulse?
During the reverse running period, the Q output of the 7 rip 70 tube becomes a high level (low level, the Q output is shown in Figure 5) as shown in Figure 5 (0), and on the other hand, after t7 During the forward running period, when the waveform [F]) rises, the waveform (Al is at a high level) is the Q of the flip-flop circle.
Output is at a high level.

Q output becomes low level. Therefore, a signal containing direction information is obtained from the flip-flop I. On the other hand, the monostable multivibrator (15+) forms a narrow pulse with a pulse width T+, and in this embodiment, the leading edge (rising edge) of the output pulse of the second detection element (9) shown in FIG. ] is triggered at time point 11 to t shown in Figure 5) and sends out the positive pulse 'kQ output terminal with a pulse width TI, and at the same time outputs the negative pulse 'kQ of pulse mT+ shown in Figure 5 [F]. Send from the terminal.Following work, Figure 5 ■ and [
The pulse train of F] is a frequency signal corresponding to speed and includes speed information. 1st AND game) (161 is the input of the Q output of the simple multivibrator α and the Q output of the In flip 70 tube (141), and the An AND output is generated as shown in FIG. During the forward running period after 11, the waveform (0) is at a high level, so the positive speed signal obtained from the Q output terminal of the monostable multivibrator Q51 passes through the gate ae, and a positive pulse train is obtained.

On the other hand, the second AND gate σn connects the Q output of the monostable multi-bi break a9 and the Q output of the 7 lip-flop a knob, and outputs a logical product of the waveform IF shown in FIG. (l'Y is output. Therefore, during the backward traveling period from 11 to t7, a negative speed signal is generated from the second AND gate α force, and during the subsequent forward traveling period, the output is at a low level. The OR gate bet is the output of al and the second AND gate (1618η), and the waveform (the waveform obtained by adding 0 and 1 (Ill small output, that is, the OR game) Q& From t1 to t7, a negative speed signal is generated during the backward running period, and a positive speed signal is generated during the forward running period after t7.

In short, a single pulse train can be sent out in which the pulse period T3 of one width T+ is used as speed information and the pulse polarity is used as direction information.

A single pulse signal containing both speed and direction information is transmitted to the receiving circuit GIJ in a single transmission t) 24 (20J) with a delay coupled to the input terminal [21a] of the receiving circuit Q11. The circuit 1221 converts the input waveform fIl into a time T,
Delay it. Therefore, at the output stage of the delay circuit, a waveform (i! extended height output as shown in Jl) is obtained through a waveform shaping circuit.

The D input terminal of the D-type 7 lip-flop f241 is coupled to the transmission line 4 through the input terminal and the clock input terminal +ClO can be fully coupled into the waveform shaping circuit, and the output waveform of the waveform shaping circuit (the high level of Jl The waveform (
Since the level of II is read, the flip-frog f2 is set from 11 to 10 hours, which corresponds to the period of running in the reverse direction.
The Q output of 41 becomes high level as shown in the waveform [+, -
10,000, t, which corresponds to traveling in the forward direction, becomes a low level in subsequent periods. That is, a waveform σ0 containing direction information substantially corresponding to waveform D) is obtained. The output of the waveform shaping circuit is coupled to the clock input terminal [CK] of the up/down counter (c), and the Q output of the flip 70 (241) is coupled to the up/down control input terminal UP/DOWN. Then, the counter e5) goes into a down operation in response to the high level output of the 7 lip-flop 1241 shown in waveform K), and goes into a °C up operation in response to the low level output. That is, t, ~t.

During the backward traveling period, a down-count operation is performed using the nine-pole pulse shown in the waveform Ul as input, and during the forward-direction traveling period after t, an up-count operation is performed using the positive pulse pulse. As a result, it is possible to obtain a calculation output corresponding to the speed, that is, the amount of tape travel.

In addition, in the waveform +Il and mark in FIG. 5, the pulse width T1
Is the pulse width T1 sufficiently short (and shorter than the delay time T)?Also, the pulse width T1 is set to be smaller than the 172 time period of the pulse period T3 corresponding to the maximum speed. Also, )! ! The extension time T is set to be shorter than the pulse period Ts corresponding to the maximum speed V
,ing.

As is clear from the above, according to one embodiment.

Since the single pulse train shown in the waveform CI+ includes both velocity information and direction information, image information can be sent through a single transmission path (2). Therefore, it becomes possible to simplify the transmission path.

In addition, by configuring the transmitting circuit (131 and receiving circuit + 211) as shown in FIG. 4, it is possible to easily perform (counting) based on the waveform (formation of II and waveform σ). It is not limited to the above embodiments.

For example, the following modifications are included.

(In order to obtain a waveform indicating the direction based on the Al waveform (II), replace the delay circuit (221 with (single stable multi-pipe rake + 22a) as shown in Figure 6) and perform the i*v flip of this output pulse. It is also possible to use a clock input of 70 (241).

B) Speed information and direction information are not limited to the speed detection method using ton, magnetic %, conversion (it may also be obtained using a speed detection method using 1-to-1 conversion, etc.).

[Brief explanation of the drawing]

Figures 1 and 2 are block diagrams showing conventional tape counters, and Figure 3 is the output waveform of the detection element in Figure 2. The waveform diagram shown in FIG. 4 is a counting device according to an embodiment of the present invention. FIG. 5 is a waveform diagram showing the states of points A to A in FIG. 4, and FIG. 6 is a block diagram showing a modification of the direction detection method. (la) (1b) - reel, +71 ... disc,
+81 (91-...detection element. a4...transmission circuit, u4J...D type flip 70
Tubu, (151...monostable multibibreak, t
lulη...AND gate. Q~...OR game), (201...transmission line, fa
ll...Reception circuit, (2a...Delay circuit, (c)
...Waveform shaping (b) path, r24...D type flip 70
Tsubu, c! 9...Up/down counter.

Claims (1)

[Claims] When transmitting the moving speed information and moving direction information of the object,
The generation period of the pulse is made to correspond to the speed information, the polarity of the pulse is made to correspond to the direction information, and the width of the pulse is made to correspond to the period of the pulse at the maximum moving speed of the object.
A method for transmitting speed and direction information characterized by transmitting a single pulse train set to be smaller than 72.