JPS6315530B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-channel recorder having a plurality of recording channels for recording a plurality of input signals on recording paper.

As is well known, in a multi-channel recorder that has multiple recording channels, the pen of each recording channel (hereinafter referred to as "channel") records multiple input signals simultaneously over the entire width of the recording paper. In addition to being installed offset in the paper feed direction, the input signal of each channel is adjusted based on the pen position shift and the paper feed speed so that even when multiple input signals are recorded simultaneously, the time relationship of the recording results of each channel is the same. , and this delayed signal is applied to the pen driving section as a recording signal. In this case, it is more convenient and highly accurate to perform delay processing of the input signal digitally, so by appropriately setting the number of storage stages N of the memory means such as a shift register and the period T of the clock pulse. , the delay time N·T is obtained.

By the way, in order to obtain a predetermined delay time N·T in such a recorder, the number of storage stages N is
When determining the number of storage stages N and one cycle T of the clock pulse, changing the number of storage stages N according to the pen position deviation and the recording paper feed speed involves various difficulties in the circuit configuration. The period T of the clock pulse is fixed to a value proportional to the amount of positional deviation, and then changed in accordance with the recording paper feeding speed.

However, doing this means that the sampling interval of the input signal changes depending on the chart paper feed speed. For example, if the record feed speed becomes slow, gaps may occur in the input signal recording, and the input signal The disadvantage is that the fidelity of the recording is compromised. In particular, this drawback becomes more noticeable when the time width of the input signal waveform is short and the rising and falling edges are _{steep .} The maximum value shown by is missing,
This has the disadvantage that it is recorded as a signal with a waveform as shown in FIG. 1c.

In addition, in Figures 1a to d, figure b is the same as figure a.
Figure d is an enlarged view of Figure c.

Here, such drawbacks may be solved by shortening the sampling period of the input signal and further increasing the number of storage stages N of the memory means such as a shift register, but if this is done, the memory means The structure of has become large-scale,
This is unfavorable in terms of equipment scale and economy.

The present invention has been made to solve these drawbacks, and its purpose is to prevent the recording of input signals from being lost and to record faithfully to the input signals with a small-scale and economical configuration. The object of the present invention is to provide a multi-channel recorder.

To this end, the present invention detects the representative value of the input signal within each unit period corresponding to the chart paper feed speed, and delays this representative value according to the chart paper feed speed and the positional deviation of the pen. After that, it is applied as a recording signal to the drive unit of the pen. As the representative value, one or both of the maximum value and the minimum value is selected as appropriate.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 2 is a block diagram showing an embodiment in which the present invention is applied to a recorder having two recording channels.

In the figure, an input signal of a first channel CH1 is sent to a servo motor 2 via an amplifier 1. The position of the slider of the potentiometer 3 is moved by the servo motor 2. The movement of the slider of the potentiometer 3 is transmitted to the pen 4 via a pen moving mechanism (not shown). As a result, the pen 4 moves to follow the input signal and records a waveform corresponding to the input signal on the recording paper.

On the other hand, in the second channel CH2,
AD converter 5, maximum/minimum value detector 6, delay circuit 7, interpolation calculator 8, DA converter 9, sampling pulse generator 10, oscillator 11, frequency divider 12, chart paper feed speed switch 13, Amplifier 14, servo motor 15, potentiometer 16, pen 1
7. A 1/2 frequency divider 18 is provided, and the input signal is AD
A sampling pulse generator 10 in the converter 5
The period t of the sampling pulse SP generated from
The signal is converted into a digital signal and sent to a maximum/minimum value detector (hereinafter abbreviated as a detector) 6.

The period base t of the sampling pulse SP is set to be extremely shorter than the unit period T corresponding to the recording paper feed speed, and this sampling pulse SP is set to be extremely shorter than the unit period T corresponding to the recording paper feed speed. It is used as a signal to determine the minimum value detection operation cycle and the interpolation operation cycle of the interpolation calculator 8. The input signal converted into a digital signal by the AD converter 5 is converted to the maximum value in the unit period T corresponding to the recording paper feeding speed by the detector 6.
Mx, the minimum value Mn is detected. FIG. 3a shows an example of an input signal applied to channel CH2, and FIG. 3b shows an enlarged view thereof.

The detector 6 has a unit period T as shown in FIG. 3b.
A reference value memory Ms stores the input signal D ₀ at the start time t ₀ as a reference value, and input signals showing the maximum positive and negative deviations from the reference value within the unit period T are stored as the maximum value Mx and the minimum value, respectively. Maximum deviation detector MDD to detect as value Mn and this detector
Maximum value Mx and minimum value detected in MDD
A first memory _M1 and a second memory storing Mn
_M2 , and the detection of the maximum deviation is performed at the period t of the sampling pulse SP. Therefore,
In the case of an input signal as shown in FIG. 3b, the instantaneous value _D0 of the input signal is stored as a reference value in the reference value memory Ms, and the instantaneous value _D2 is stored as the minimum value Mn in the second memory _M2. , furthermore, the instantaneous value D ₃ is the maximum value M ₁
It is stored in the first memory _M1 as . in this case,
In the period from t ₀ to t ₁ , the instantaneous value D ₁ is the maximum value
It is detected as Mx and first stored in the first memory _M1 . Next, in the period from t ₁ to t ₂ , the instantaneous value
Since D ₂ is detected as the minimum value Mn, the period t ₀ ~
The instantaneous value D ₁ stored in the first memory M ₁ as the maximum value Mn at t ₁ is transferred to the second memory M ₂ . Then, the instantaneous value _D2 is stored in the first memory _M1 as the minimum value Mn
is stored as. Next, in the period from t ₂ to _{t 3} , an instantaneous value D ₃ with a larger positive amplitude than the instantaneous value D ₁ transferred to the second memory M ₂ is detected, so it is transferred to the first memory M _1. The instantaneous value _D2 stored as the minimum value Mn is transferred to the second memory _M2 , and
The instantaneous value _D3 is stored in _M1 as the maximum value Mx.
That is, the instantaneous value D ₁ detected as the maximum value Mx between t ₀ and t ₁ appears to be driven out by the instantaneous value D ₃ that appears thereafter.

In this way, the configuration of the first memory _M1 and the second memory _M2 is not fixed to store either the maximum value Mx or the minimum value Mn, but the order in which the maximum value Mx or the minimum value Mn appears. If the configuration is configured to sequentially feed the first memory M ₁
The latest maximum or minimum value is stored in the second memory M2, and the previous maximum or minimum value is stored in the second memory _M2 , so the detected maximum and minimum values can be stored in the order in which they occurred. Therefore, it can be recorded.

The maximum value Mx and the minimum value Mn stored in the first memory _M1 and the second memory _M2 in this way
The delay circuit 7 is controlled by a control pulse CP' having a period T, which is obtained by dividing the control pulse CP having a period T/2 selected by the recording paper feed speed changeover switch 13 by a half period 18.
will be forwarded to.

A channel speed changeover switch (hereinafter abbreviated as a changeover switch) 13 selects a divided output with a period T/2 corresponding to the recording paper feed speed from among the divided outputs of the frequency divider 12, It is applied to the delay circuit 7 and the recording paper feed motor M, and is applied to the detector 6 and the motor M as a control pulse CP' with a period T via a 1/2 frequency divider 18. In this case, the input signal to the frequency divider 12 is given from the oscillator 11.

Further, the delay circuit 7 is constituted by a memory means consisting of, for example, a shift register (including one that operates equivalent to a shift register), and has a maximum value Mx and a minimum value detected in the period T by the detector 6.
Mn is supplied to the interpolation calculator 8 with a delay depending on the recording paper feed speed v and the pen position deviation l.

Here, the period T/2 of the control pulse CP, the recording paper feed speed v, and the delay time td of the delay circuit 7 are the first
The positional deviation between the pen 4 of the second channel and the pen 17 of the second channel with respect to the recording paper feeding direction is determined by the fourth
As shown in the figure, let 1 be the number of storage stages when the delay circuit 7 is constituted by a shift register, and let the number of storage stages be N. The following relationship exists.

td=N・T/2=l/v...(1) Therefore, when the number of storage stages N is fixed, the period T of the control pulse CP is T=2・l/N・1/v... The relationship is as shown in (2), and it is given as a time proportional to the reciprocal of the recording paper feed speed v.

Therefore, when a control pulse CP' having such a relationship is applied to the detector 6, the value stored in the second memory _M2 at the end of the period T is first stored in the second storage stage of the delay circuit 7. , also the first memory
The value stored in M ₁ is transferred to the first storage stage of the delay circuit 7. Then, these values are transferred from the first and second storage stages to the N-1st and Nth storage stages every time the control pulse CP occurs (every T/2 period).
are sequentially transferred to the storage stage. Then, after the td time has elapsed, the signals are supplied to the interpolation calculator 8 from the N-1 and N-th stages. That is,
Maximum value Mx of input signal detected by detector 6
And the minimum value Mn is delayed by td time and transferred to the interpolation calculator 8.

The interpolation calculator 8 calculates an interpolated value for each unit time from the value of the A part to the value of the B part based on the value input to the A part and the value input to the B part every cycle T/2. The interpolation calculation is based on the sampling pulse SP
is executed at a period t.

For example, if the input signal is as shown in FIG. 3b, the instantaneous value D2 indicating the minimum value Mn is input to the interpolator 8 as the first value, and then the instantaneous value _D2 indicating the maximum value Mx is input to the interpolator 8. The instantaneous value D ₃ is input as the second value, and then the maximum value Mx in the next period T
When the instantaneous value D ₄ indicating , is input as the third value, in the first half T/2 of the period T, an interpolated value Dip expressed by the following equation is determined and output every time the sampling pulse SP occurs.

Dip=D ₂ +D ₃ −D ₂ /T/2·n (3) where n is the number of sampling pulses SP generated.

In addition, in the latter half T/2 of the period T, an interpolated value Dip expressed by the following equation is obtained and output every time the sampling pulse SP occurs.

Dip=D ₃ +D ₄ -D ₃ /T/2・n...(4) As a result, the interpolator 8 outputs a value that changes as shown in FIG. 3d every time the sampling pulse SP occurs. do.

The output of this interpolator 8 is converted into an analog signal by a DA converter 9. Changes in the analog signal are then transmitted to the potentiometer 6 via the amplifier 14 and the servo motor 15.
As a result, the pen 17 of the second channel is
The third
A waveform as shown in Figure c is recorded on recording paper. That is, a waveform that approximates the input signal at period T is recorded on the recording paper.

In this way, the present embodiment detects the maximum and minimum values of the input signal in the period T as the representative values of the input signal in the period, delays the representative values for a predetermined period of time, performs interpolation calculations, and uses the calculated values as the pen's values. The signal is transmitted to the driving part. For this reason,
Even if the recording paper feeding speed becomes slow, no recording loss occurs, and recording that approximates the input signal can be performed. Furthermore, since interpolation calculations are performed, the movement of the pen becomes smooth, and it is possible to obtain a recording result that is aesthetically pleasing without causing ink smearing. In particular, in the past, when recording a sine waveform as shown in Fig. 3e, if the sampling period coincides with the period of the sine wave input signal, the sine waveform shown in Fig. 3f
As shown in Figure 3g, no waveform is recorded at all, and if the sampling period and the period of the sine wave input signal deviate by half a period, it is recorded as a rectangular wave as shown in Figure 3g. In the third
As shown in Figure h, it is recorded as a waveform that approximates a sine wave input signal, making it possible to improve the reproducibility of the input signal.

In this case, when the reproducibility of the input signal is not so required, the maximum value Mx and the minimum value Mn, whichever has a larger deviation from the reference value, is transferred to the delay circuit 7, and the interpolation calculation in the interpolation calculator 8 is as follows. It is also possible to perform the period T between the representative value of the period T and the representative value of the period T. Further, either the maximum value Mx or the minimum value Mn is transferred to the delay circuit 7,
Even if the input signal is transmitted to the driving part of the pen without performing interpolation calculations, the reproducibility of the input signal will decrease, but omissions can be prevented, and it is applicable to recorders when it is important to consider whether or not there has been a change in the input signal. If so, the practical effects will be great.

In the embodiment, there are two recording channels.
Although the case of channels has been described, in the case of three or more channels, the number N of memory stages of the delay circuit in each channel may be set in accordance with the positional shift of the pen in the channel.
Furthermore, if it is desired to further simplify the configuration, a parallel input/parallel output type shift register may be used as the delay circuit, and this shift register may be used as both the first memory and the second memory.

Furthermore, the maximum/minimum value detector, delay circuit, and interpolation calculator may be replaced with a microprocessor.

As is clear from the above description, according to the present invention, it is possible to prevent loss of input signals and perform recording faithful to the input signals with a small-scale and economical configuration.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing how an input signal is lost in a conventional recorder, Fig. 2 is a diagram showing an embodiment of the present invention, and Fig. 3 is an input/output waveform diagram for explaining the operation of the embodiment. , FIG. 4 is a diagram showing the state in which the pen is attached. 1,14...Amplifier, 2,15...Servo motor, 3,16...Potentiometer, 4,17...
...Pen, 5...AD converter, 6...Maximum/minimum detector, 7...Delay circuit, 8...Interpolation calculator, 9...
...DA converter, 10 ... sampling pulse generator, 11 ... oscillator, 12 ... frequency divider, 13 ...
Chart paper feed speed selection switch, 18...1/2 frequency divider, M...Chart paper feed motor.

Claims (1)

[Scope of Claims] 1. A plurality of pens that are mounted with their positions shifted in the recording paper feeding direction and record input signals of corresponding channels on the recording paper, and a pen that corresponds to the positional shift of the pens and the recording paper feeding speed. In a multi-channel recorder having a delay circuit consisting of at least one shift register that delays the input signal of each channel, at least one channel is connected to comprising a detection means for detecting a representative value consisting of at least one of a maximum value and a minimum value of an input signal within a period, and supplying the representative value detected by the detection means to the delay circuit of its own channel. Features a recorder. 2. A plurality of pens whose positions are shifted in the recording paper feeding direction and record the input signals of the corresponding channels on the recording paper, and the input signals of each channel are recorded according to the positional deviation of the pens and the recording paper feeding speed. In a multi-channel recorder having a delay circuit consisting of at least one or more shift registers for delaying a a maximum/minimum value detector that detects maximum and minimum values and sequentially supplies the maximum and minimum values to the delay circuit of its own channel according to the order in which they appear; A recorder comprising an interpolation calculator that interpolates the minimum value and outputs the calculated value as a pen recording signal. 3. The maximum/minimum value detector includes a reference value memory that stores the input signal at the start point of each unit period as a reference value, and a maximum positive and negative deviation from the reference value within the unit period. a maximum deviation detector for detecting an input signal, and a first memory and a second memory for storing input signals indicating the positive and negative maximum deviations as the maximum value and minimum value, respectively, and supplying the input signals to the delay circuit of its own channel. 3. The recorder according to claim 2, further comprising a memory. 4. The first memory and the second memory store the latest maximum value or minimum value in the first memory, store the previous maximum value or minimum value in the second memory, and store the latest maximum value or minimum value in the second memory, and store the latest maximum value or minimum value in the second memory, and store the latest maximum value or minimum value in the second memory. 4. The recorder according to claim 3, characterized in that the recorder has a sequential configuration in which the recorder is supplied to the circuit.