JPH063372A - Digital sampling oscilloscope apparatus,method for measuringtime-axis error thereof and method of calibration - Google Patents

Abstract

PURPOSE: To measure a time-base error of an oscilloscope apparatus itself and correct the error by measuring the time-base error by calculating the difference of the measured value of the cycle of the sinusoidal wave signal and the cycle of the sinusoidal wave. CONSTITUTION: After the threshold voltage of a trigger circuit 1 is set to be approximately the center voltage of the sinusoidal wave signal, a microprocessor 7 measures the hour every time when the sinusoidal wave signal reaches the threshold voltage at the defined voltage level. The measured times arranged in the time order to the latest (measured time series) are defined as t0 , t1 ..., tn-1 , tn (t0 <t1 <...<tn-1 <tn ) and the relative time-base error ek at the time tk (K=1, 2...n) from the time t0 is computed. The relative time-base error Δek at the time tk from the time tk-1 can be computed based on the cycle T computed from the set frequency of the sinusoidal wave signal and the measured value Tk of the cycle. The relative time-base error ek at the time tk from the t0 on the time base can be calculated as the sum from the Δe1 to Δek .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for measuring and observing electric signals with picosecond-order time-axis accuracy.
The present invention relates to a digital sampling oscilloscope device.

As a specific field of use of the present invention, measurement of an electric signal which requires high time base accuracy, for example,
Timing generation circuit used in integrated circuit test equipment,
An example is the evaluation of the timing measurement circuit. The time axis error measuring method of the present invention can be used for evaluating the time axis characteristic of an oscilloscope device.

[0003]

2. Description of the Related Art A time base error of a digital sampling oscilloscope device is an error due to a deviation of a frequency standard built in the oscilloscope device for generating a sampling timing, and an analog delay circuit for generating a timing less than the cycle of the frequency standard. The error can be classified into an error due to the deviation between the maximum delay amount and the cycle of the frequency standard, and an error caused by the nonlinearity of the delay amount of the analog delay circuit.

A method of calibrating the deviation of the frequency standard and a method of calibrating the deviation of the maximum delay amount of the analog delay circuit and the cycle of the frequency standard are known, and the cause of these causes can be obtained by receiving the calibration service provided by the manufacturer. It is possible to reduce the error caused by. For example, according to the Hewlett-Packard Oscilloscope Device Service Manual (54120-90908), the former calibration applies a sine wave signal having only a component of the same frequency as the frequency standard to the oscilloscope device from the outside, and When the time axis scale (Time / Div) of the oscilloscope device is set so that the sampling period is an integer multiple of the period of the frequency standard, set the frequency standard frequency so that the display of the oscilloscope device screen is completely horizontal. It is done by adjusting. In the latter calibration, the sine wave signal is applied to the oscilloscope device from the outside, and when the time axis scale (Time / Div) of the oscilloscope device is set to the maximum, the analog delay circuit becomes the maximum delay amount, and This is done by adjusting the maximum delay amount of the analog delay circuit so that the waveform displayed above becomes continuous.

However, the delay characteristic of such an analog delay circuit has non-linearity unique to each digital sampling oscilloscope device, and it has not been conventionally performed to calibrate a time base error caused by the non-linearity. The time axis error specification of a commercially available digital sampling oscilloscope device is set to allow an error due to the non-linearity of an analog delay circuit. for that reason,
Even in the commercially available digital sampling oscilloscope device having the highest time axis accuracy, the specification value of the time axis accuracy is about 10 ps, and it is not possible to obtain the time accuracy on the order of picoseconds. Conventionally, it is impossible to remove the error due to the non-linearity of the analog delay circuit from the measurement data of the oscilloscope device, which has been a cause of hindering the improvement of the time base accuracy of the oscilloscope device.

[0006]

Increasing speed of semiconductor technology,
With high integration and high frequency, it is necessary to observe electric signals with high time accuracy. In particular, in order to evaluate the timing generation circuit and the timing measurement circuit used in the integrated circuit test apparatus, it is necessary to measure the electric signal with a time axis accuracy of the picosecond order.

However, as described above, it is difficult for the conventional digital sampling oscilloscope device to measure and observe an electric signal with picosecond-order time-axis accuracy. Further, it has not been performed so far to measure and calibrate a time axis error caused by the nonlinearity of the analog delay circuit, which is a factor that deteriorates the time axis accuracy of the oscilloscope device.

Therefore, an object of the present invention is to solve the problem that the time-axis accuracy of a digital sampling oscilloscope device is worse than the required accuracy, and to eliminate the time-axis error of the oscilloscope device itself caused by the nonlinearity of the analog delay circuit. An object of the present invention is to provide a digital sampling oscilloscope device capable of measuring and calibrating.

Another object of the present invention is to solve the above problems,
An object of the present invention is to provide a digital sampling oscilloscope device capable of measuring an electric signal with a time base accuracy of the picosecond order.

Still another object of the present invention is to provide a method for measuring the time base error of a digital sampling oscilloscope device.

Still another object of the present invention is to measure the time base error of a digital sampling oscilloscope device,
It is to provide a method for calibrating a time axis error based on the obtained time axis error.

[0012]

In order to achieve the above object, the invention according to claim 1 is a sine having only a single frequency component, a channel input terminal for receiving a channel input, a trigger terminal for receiving a trigger input. Supply a wave signal as a measurement standard to the channel input terminal and the trigger terminal,
Means for obtaining a measurement time series by measuring all the time when the voltage level of the sine wave signal reaches a predetermined threshold voltage in a rising or falling state over a predetermined range on the time axis on the display surface of the oscilloscope device. , T ₀ , t ₁ , ..., T _n-1 , t _n (t ₀ <t ₁
<... <t _n-1 <t _n ) and the difference between adjacent measurement times, T _k = t _k −t _k−1 (k = 1, 2, ..., N) is set as the cycle measurement value. when the difference between the measured value T _k of the period and the period T of the sine wave signal, a time at time t _k t _k-1
Means for obtaining a relative time axis error Δe _k from
Relative time base error e from time t _{0 at} time t _k
The _k, comprises a means for determining from the sum from .DELTA.e ₁ to .DELTA.e _k, characterized by being adapted to measure the time base error.

According to a second aspect of the present invention, a channel input is received.
Channel input terminal and trigger end that receives the trigger input
And a sinusoidal signal with only a single frequency component
As a rule, to the channel input terminal and the trigger terminal
Supply, the voltage level of the sine wave signal rises and
Is the time when the threshold voltage is reached in the falling state
On the display surface of the oscilloscope device on the time axis.
It is important to measure all over the
Repeated multiple times by changing the frequency setting of the sine wave signal
Means and one of the measurement time series,₀ , T₁ ，
…, T_n-1 , T_n(T₀ <T₁ <... <t_n-1 <T_n )When
Then, the difference between adjacent measurement times, T _k = T_k -T
_k-1 Let (k = 1, 2, ..., N) be the measured values of the period.
The measured value T of the cycle_k And the period T of the sine wave signal
At time t_k At time t_k-1 Relative time axis from
Error Δe_k And the time t_k Time in
t₀ Relative time axis error e from_k Is Δe₁ To Δe
_k For all measurement time series,
And the time t_k From the origin at
Absolute error E of the axis_k To all k (k = 0,1, ..., n)
The averaged value for each measurement time series
Assuming they are equal, time t₀ From the origin at
Absolute error E between axes₀ Is calculated for all measurement time series
At time t_k Error E on the time axis from the origin at_k 
The E₀ And e_k All measurement times should be calculated from the sum of
A means to perform for all k in the sequence,
The feature is that the axis error is measured.

According to a third aspect of the present invention, a channel input terminal for receiving a channel input, a trigger terminal for receiving a trigger input, and a sine wave signal having only a single frequency component as a measurement standard are the channel input terminal and the trigger terminal. The time at which the voltage level of the sine wave signal reaches the predetermined threshold voltage in the rising state is measured over the predetermined range on the time axis of the oscilloscope device, and the predetermined threshold is further measured in the falling state. The time to reach the value is measured over the predetermined range to obtain both the measurement time series in the rising state and the measurement time series in the falling state, and the voltage level of the sine wave signal is the predetermined threshold voltage. Measurement time system to measure all the time to reach the To obtain a plurality of measurement time series by changing the threshold voltage and repeating, to obtain a plurality of measurements from a single frequency setting of a sine wave signal. A means for obtaining a time series and one of the plurality of measurement time series are t
₀ , t ₁ , ..., T _n-1 , t _n (t ₀ <t ₁ <... <t _n-1
<T _n ) and the difference between adjacent measurement times, T _k
= T _k −t _k−1 (k = 1, 2, ..., N) as the measured value of the period, the measured value T _k of the period and the period T of the sine wave signal applied to the oscilloscope device are The difference is the time t
relative time base error .DELTA.e _k from time t _k-1 in the _k
And a means for executing relative time axis error e _k at time t _k from time t ₀ from the sum total of Δe ₁ to Δe _k for all measurement time series. Assuming that the values obtained by averaging the absolute errors E _k on the time axis from the origin at time t _k over all k (k = 0, 1, ..., N) are equal to each measurement time series, The absolute error E ₀ of the time axis from the origin at t ₀ is calculated, and the absolute error E _k of the time axis from the origin at time t _k is calculated for all _{k from} the sum of E ₀ and e _k. And a means for executing all measurement time series, so that the time axis error is measured.

According to a fourth aspect of the present invention, means for sampling an input signal at a predetermined sampling time to perform A / D conversion, and a data memory for storing the digital signal obtained by the A / D conversion and the sampling time. And a frame memory for storing graphic data, a means for extracting digital signal data required for display from the data memory, converting the data into graphic data, and writing the graphic data in the frame memory, and a graphic data held in the frame memory as an analog signal. A means for converting and a display for displaying the analog signal thereof, and claim 1 or 2.
1 to 3, an error memory that stores the time-axis error measured in any one of 3 to 3, a unit that interpolates the time-axis error at the sampling time point based on the measurement result of the time-axis error stored in the error memory, and the interpolation. A means for storing the time obtained by subtracting the stopped time axis error from the sampling time in the data memory as the sampling time after time axis error calibration is provided to calibrate the time axis error of the oscilloscope device itself. It is characterized by having done.

According to a fifth aspect of the present invention, means for sampling the input signal at a predetermined sampling time to perform A / D conversion, and a data memory for storing the digital signal and sampling time obtained by the A / D conversion. And a frame memory for storing graphic data, a means for extracting digital signal data required for display from the data memory, converting the data into graphic data, and writing the graphic data in the frame memory, and a graphic data held in the frame memory as an analog signal. A means for converting and a display for displaying the analog signal thereof, and claim 1 or 2.
To an error memory for storing the time base error measured in any one of 1 to 3 and a function form of the time base error for each factor that causes the time base error of the oscilloscope device. Every time, the magnitude of the time axis error of the oscilloscope device is expressed as the sum of all function types with unique weights, and each weight is the measurement result of the time axis error stored in the error memory. Means for deriving an approximation function representing a time axis error, an approximation function memory for holding the approximation function calculated by the means, and a time axis error at the sampling time for the approximation held in the approximation function memory. The time axis error is calculated by using the function and the time obtained by subtracting the calculated time axis error from the sampling time. As the sampling time after a positive, comprising a means for storing in the data memory, and is characterized in that so as to calibrate the time base error with the oscilloscope device.

According to a sixth aspect of the present invention, in the digital sampling oscilloscope device according to the second aspect, the range (S) for measuring the time base error is set to the period (frequency) of the frequency standard for sampling time generation incorporated in the oscilloscope device. Range (T ₀ × p) obtained by multiplying T ₀ by p times (p is an integer)
And q _m from a plurality of m (m> 1) different integers q ₁ , q ₂ , ..., Q _m that are coprime to the integer p. ₁ / S,
q ₂ / S, ..., and means for determining the q _m / S, characterized by being configured to measure the time base error.

The invention according to claim 7 is the invention according to claims 1, 2, and 3.
Alternatively, in the digital sampling oscilloscope device described in 6, the sine wave signal as the measurement standard is
The voltage is supplied to the channel input terminal by coupling, the trigger level voltage of the oscilloscope device is set to 0V, and the time when the voltage level of the sine wave signal reaches 0V on the time axis on the display surface of the oscilloscope device. It is characterized in that the measurement is performed over the predetermined range.

According to an eighth aspect of the invention, the time axis error of the oscilloscope device itself is measured, and the waveform data measured by the oscilloscope device is corrected by using the measurement result of the time axis error. In a method of calibrating a time axis error, a first step of applying a sine wave signal of a predetermined frequency having only a single frequency component to the oscilloscope device and a range on the display screen of the oscilloscope device on the time axis. , The second step of measuring the time when the voltage level of the sine wave signal reaches a certain set voltage as data representing the time position on the display surface, and the measurement time series thereof are t ₀ , t ₁ , ... , T _n-1 ,
t _n (t ₀ <t ₁ <... <t _n-1 <t _n ) and the difference between adjacent measurement times, T _k = t _k −t _k−1 (k = 1, 2, ...,
When n) is the measured value of the period, the measured value T _k of the period and the period T of the sine wave signal applied to the oscilloscope device.
Difference and a third step of obtaining a relative time base error .DELTA.e _k from time t _k-1 at time t _k with, .DELTA.e
Time t at time t _k from the sum of ₁ to Δe _{k
And a} fourth step of obtaining a relative time axis error e _k from ₀ , the time axis error of the oscilloscope device itself is measured.

According to a ninth aspect of the present invention, in the time axis error measuring method according to the eighth aspect, the period T ₀ of the frequency standard which is built in the oscilloscope device and generates sampling timing is multiplied by p (p is an integer). And the fifth step of setting the range on the time axis on the display surface of the oscilloscope device as the range S (= T ₀ × p) for measuring the time axis error, and the integer p are relatively prime, m (m>
1) number of mutually different integers greater than ₁ q ₁ , q ₂ ,
, Q _m , the frequency of the sine wave signal is changed to q ₁ / S, q
_{The second} step of determining the ₂ / S, ..., Q _m / S, and the time axis of the oscilloscope device determined in the fifth step for each of the m frequencies determined in the sixth step. A seventh step of obtaining a relative time axis error e _k from the time t _{0 at} the time t _k by the method according to claim 1 over the above range, and an absolute error of the time axis from the origin at the time t _k . E _K for all k (k = 1,
2, ..., N), the eighth step of calculating the absolute error E ₀ on the time axis at time t ₀ under the assumption that the values averaged over all the frequency settings of the sinusoidal signal are equal. _From the sum of ₀ and e _k , the absolute error E _K of the time axis at time t _k is calculated for all k
And a time axis error of the oscilloscope device is measured.

According to a tenth aspect of the present invention, in the time axis error measuring method according to the eighth or ninth aspect, the time at which the voltage level of the sine wave signal reaches a certain set voltage in the second step is set by the oscilloscope device. When measuring on the display surface, a method of measuring both the time when the voltage level of the sine wave signal reaches the set voltage at the time of rising and the time when it reaches the set voltage, by changing the trigger voltage level of the oscilloscope device. , How to repeat the measurement,
And a method of repeating the measurement by changing the set voltage for measuring the period of the sine wave signal, and using a plurality of measurement times t ₀ , t from a single frequency of the sine wave signal. ₁ , ..., t _n-1 , t _n (t ₀ <t ₁ <
<T _n-1 <t _n ) is obtained, and the relative time axis error e _k from the time t _{0 at the} time t _k is calculated for each measurement time by the third and fourth steps. The time axis error of the oscilloscope device is measured by performing the required measurement and obtaining the absolute error E _k of the time axis at the time t _k in the eighth and ninth steps.

The eleventh aspect of the present invention is the time axis error measuring method according to the eighth, ninth or tenth aspect, wherein the sine wave signal having only the single frequency component is AC coupled in the first step. The oscilloscope device is supplied to the calibration target oscilloscope device, and in the second step, the time at which the voltage level of the sine wave signal reaches 0 V in the range on the time axis on the display surface of the calibration target oscilloscope device is set to the oscilloscope device. It is characterized by reading on the display surface of.

According to a twelfth aspect of the present invention, a first step of measuring a time base error of the oscilloscope device itself, a second step of storing a measurement result of the time base error in an error memory, and the oscilloscope device. The third step of interpolating the magnitude of the time-axis error at the time on the waveform data measured by the above from the measurement result of the time-axis error, and the time-axis error obtained by the interpolation A fourth step of performing subtraction from time to obtain a calibrated time over all times on the waveform data, and displaying the waveform data at the calibrated time position on the display of the oscilloscope device. And a fifth step.

According to a thirteenth aspect of the present invention, the first step of measuring the time base error of the oscilloscope device itself, the second step of storing the measurement result of the time base error in the error memory, and the time base The third step of calculating an approximate function representing the time base error of the oscilloscope device from the error measurement result, and the magnitude of the time base error at the time with respect to the time on the waveform data measured by the oscilloscope device. Is calculated from the approximation function
And a fifth step of subtracting the calculated time axis error from the time to obtain a calibrated time over all the times on the waveform data, and the step of: A sixth step of displaying the waveform data at the calibrated time position.

According to a fourteenth aspect of the present invention, in the time axis error calibration method according to the thirteenth aspect, for each factor that causes the time axis error of the oscilloscope device, a function representing the magnitude of the time axis error due to the factor is generated. A seventh step of obtaining and a time axis error as a sum of all the factors obtained by weighting the obtained function, and each weight is obtained from the measured value of the time axis error by regression analysis. And a step of calculating the approximate function representing the time base error of the oscilloscope device.

[0026]

According to the present invention, the time axis error of the oscilloscope device itself is measured at a plurality of times on the time axis, and the time axis error is calibrated using the measurement result and input to the display surface of the oscilloscope device. The time axis accuracy of the oscilloscope device can be improved by providing the digital sampling oroscope device with the function of displaying a waveform.

In the present invention, the sine wave signal generator is connected to the oscilloscope device and started when a key input for starting the time base error measurement is made. The period of the sine wave signal is measured on the oscilloscope device, The time base error of the oscilloscope device is measured by calculating the difference between the measured period value and the period of the sine wave signal. The measured time axis error is stored in the error memory and used in the time axis error calibration during the period until the next time axis error measurement is performed.

Furthermore, in the present invention, the time axis error of the oscilloscope device is calibrated using the measurement result of the time axis error measurement performed as described above, and the input voltage is calculated using the calibrated time axis error. Display on the display. Here, the time-axis error calibration function is realized by calculating the time-axis error at the sampling time from the measurement result of the time-axis error by interpolation and performing calibration. Alternatively, the time axis error calibration function derives an approximation function representing the time axis error of the oscilloscope device from the measurement result of the time axis error, calculates the time axis error at the sampling time using the approximation function, and calibrates the time axis error. It is also realized by doing.

[0029]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of a digital sampling oscilloscope device of the present invention. In FIG. 1, the trigger circuit 1 detects the time when the voltage of the trigger input reaches the set trigger voltage, that is, the threshold voltage, and generates a trigger pulse. The sampling time generation circuit 2 has a digital coarse delay circuit 2A and an analog fine delay circuit 2B, and after the trigger pulse is generated from the trigger circuit 1, generates a pulse at the sampling time based on the cycle of the frequency standard 3. Let The sampler 4 samples the channel input signal when the sampling pulse from the sampling time generation circuit 2 is input. The A / D converter 5 digitizes the channel input signal sampled by the sampler 4.
The memory 6 is composed of a program memory 6A for storing a program executed by the microprocessor 7, a data memory 6B for holding a digitized channel input signal, and an error memory 6C for holding a time axis error. The microprocessor 7 writes the digitized channel input signal in the data memory 6B and the measured time base error in the error memory 6C. Further, the microprocessor 7 reads a key switch input or an input from an external interface via the input / output circuit 8, converts the content of the data memory 6B into graphic data, and writes the graphic data in the frame memory 9. D / A converter 1
Reference numeral 1 converts the graphic data from the frame memory 9 into an analog signal for display. Display device 10
Displays its analog signal. 12 indicates a bus.

FIG. 2 is a flow chart of a program showing an embodiment of software for executing the function of measuring the time base error of the oscilloscope device itself shown in FIG. 1 at a plurality of times on the time base. This program is stored in the program memory 6A. An embodiment of the time axis error measuring function will be described with reference to FIG.

First, the sine wave signal generator 100 is connected to the oscilloscope device 300. That is, as shown in FIG. 3, the output of the sine wave signal generator 100 capable of generating a sine wave having only a single frequency component is output from the divider 200.
One is supplied from the channel input terminal of the oscilloscope device 300 to the sampler 4, and the other is supplied from the trigger terminal of the oscilloscope device 300 to the trigger circuit 1. As the sine wave signal generator 100, for example, 10 ⁻⁸
Use a synthesizer device with higher frequency accuracy. In that case, the frequency accuracy of the sine wave signal generated by the synthesizer is sufficiently high, and the error in the period of the sine wave signal is sufficiently smaller than the time base error of the oscilloscope device and can be ignored. For example, when the frequency of the synthesizer is set to 1 GHz, the error in the cycle of the sine wave signal is 1 femtosecond or less.

Next, a key input for starting the time base error measurement of the oscilloscope device 300 is performed. The key input is taken into the microprocessor 7 via the input / output circuit 8 and the following processing is executed.

First, in step S3, after setting the threshold voltage of the trigger circuit 1 to a voltage close to the central voltage of the sine wave signal, the microprocessor 7 sets the range within the range of the oscilloscope device 300 on the time axis. , At any time when the voltage level of the sine wave signal reaches the threshold voltage when the sine wave signal is in the rising state, or when the voltage level of the sine wave signal is in the falling state, Measure all times when the threshold voltage is reached. Here, the state where the voltage level of the sine wave signal applied to the oscilloscope device 300 is rising is defined as the rising state of the sine wave signal, and the state where the voltage level is falling is referred to as the falling state of the sine wave signal. Define.

An example of measuring the time when the voltage level of the sine wave signal reaches the threshold voltage in the rising state is shown in FIG.
Shown in. The reading times of the timing when the voltage level of the sine wave signal reaches the set voltage level in a rising state, that is, the measurement times arranged in ascending order (hereinafter referred to as measurement time series) are t ₀ , t ₁ , ..., T _{n. -1} , t _n (t ₀ <t
₁ <... <t _n-1 <t _n ).

In step S4, the time series t ₀ , t ₁ , ..., T _n−1 , t measured in step S3.
_{From n} , a relative time axis error e _k from time t _{0 at} time t _k (k = 1, 2, ..., N) is calculated. Here, the difference between adjacent measurement times T _k = t _k −t _k−1 (k =
1, 2, ..., N) are the measured values of the period. Relative time base error .DELTA.e _k from time t _k-1 at time t _k, the difference between the measured value T _k of the period T and the period to be calculated from the set frequency of the sinusoidal signal, .DELTA.e _k = T _k -T (k = 1, 2,
…, N).

Time t _k on the time axis of the oscilloscope device
The relative time axis error e _k from time t _{0 at}
sum from e ₁ to Δe _k

[0038]

## EQU1 ## e _k = Δe ₁ + Δe ₂ + ... + Δe _k , and e _k = T ₁ + T ₂ + ... + T _k −k × T = t _k −t ₀ −k × T (k = 1,2, …, N) holds. e _k is the microprocessor 7
In step S3, the measurement times t ₀ and t _k and the period T of the sine wave signal are obtained.

In step S5, the microprocessor 7 causes the error memory 6C to hold the time axis error e _k calculated in step S3.

By performing the above operation, relative time axis errors e ₀ , e ₁ , ..., E from the time t _{0 at} the measurement times t ₀ , t ₁ , ..., T _n-1 , t _n . it can be determined _n-1, e _n.

(Embodiment 2) FIG. 5 is a function for measuring the time base error of the oscilloscope device itself at a plurality of times on the time base by changing the frequency setting of the sine wave signal applied to the oscilloscope device in the present invention. 6 is a flow chart of a program showing an embodiment of software for executing the.
This program is stored in the program memory 6A.
This embodiment will be described with reference to FIG.

First, the sine wave signal generator 100 is connected to the oscilloscope device 300. Here again, as shown in FIG. 3, the output of the sine wave signal generator 100 capable of generating a sine wave having only a single frequency component is applied to the divider 20.
Branch at 0 and connect one to the channel input terminal of the oscilloscope device 300 and the other to the trigger terminal of the oscilloscope device 300.

Next, a key input for starting the time base error measurement of the oscilloscope device 300 is performed. The key input is taken into the microprocessor 7 via the input / output circuit 8 and the following processing is executed.

First, in step S8, after setting the threshold voltage to a voltage close to the center voltage of the sine wave signal, the microprocessor 7 causes the oscilloscope device 30 to operate.
Within the range of 0 on the time axis, the voltage level of the sine wave signal reaches the threshold voltage at the rising state at all times, or the voltage level of the sine wave signal reaches the threshold voltage at the falling state. Set all times. Further, the frequency setting of the sine wave signal applied to the oscilloscope device 300 is changed, and this time measurement is repeated a plurality of times.

In step S9, this is executed for each set time series obtained from a plurality of frequency settings of the sine wave signal, and each measured time series t ₀ , t
₁ , ..., T _n-1 , t _n (t ₀ <t ₁ <... <t _n-1 <t
_{From n} ), a relative time axis error e _k from time t _{0 at} time t _k (k = 1, 2, ..., N) is calculated. The time axis error e _k is e _k = t _k −t as in the first embodiment.
₀₋ k × T (k = 1, 2, ..., N) is used to obtain the measurement times t ₀ , t _k and the set period T of the sine wave signal.

Then, in step S10, it is determined whether or not the frequency of the sine wave signal is changed. If the result is affirmative, the process proceeds to step S11, where the frequency of the sine wave signal is reset. When the result is negative, that is, when it is not necessary to change the frequency, the process proceeds to the next step S12.

In step S12, when the absolute error on the time axis from the origin at time t _k is E _k , E
E _k is calculated by assuming that the averaged value of _k over all k (k = 0, 1, ..., N) results in an equal value C at all frequency settings of the sinusoidal signal. Absolute error E _k of the time axis from the origin at time t _k, the time t relative time base error from time t ₀ in _k e _k
, The absolute error E ₀ of the time axis from the origin at time t ₀
Plus size,

[0048]

Since E _k = t _k −t ₀ −k × t + E ₀ (k = 0,1, ..., n), assuming that the average value of the time axis error is C,

[0049]

[Equation 3]

Is satisfied. From this equation, E ₀ is

[0051]

[Equation 4]

It becomes However,

[0053]

[Equation 5]

It is Time t _k (k = 0, 1, ..., N)
Absolute error E _k of the time axis from the origin in the, e _k and E
Since it is the sum of ₀ ,

[0055]

[Equation 6]

It is calculated by

In step S13, the microprocessor 7 causes the error memory 6C to hold the time axis error E _k calculated in step S12.

By executing the above operation, the frequency setting of the sine wave signal applied to the oscilloscope device 300 is changed, and all the measurement times t ₀ , t of the respective frequencies are changed.
₁ , ..., t _n−1 , absolute error E _{0 on} the time axis at t _n ,
E ₁ , ..., E _n-1 , E _n can be obtained. As a result, it is possible to increase the number of times on the time axis for measuring the time axis error, as compared with the first embodiment.

(Embodiment 3) FIG. 6 is a flow chart of a program showing an embodiment of software for executing the function of the oscilloscope device itself to measure the time base error at a plurality of times on the time base. This program is stored in the program memory 6A. This embodiment will be described with reference to FIG.

First, the sine wave signal generator 100 is connected to the oscilloscope device 300. As shown in FIG.
The output of the sine wave signal generator 100 capable of generating a sine wave having only a single frequency component is branched by a divider 200, one of which is connected to a channel input terminal of the oscilloscope device 300 and the other of which is connected to a trigger terminal of the oscilloscope device 300.

Next, a key input for starting the time base error measurement of the oscilloscope device 300 is performed. The key input is taken into the microprocessor 7 via the input / output circuit 8 and the following processing is executed.

In steps S16, S17 and S18, after setting the threshold voltage to a voltage close to the center voltage of the sine wave signal, the microprocessor 7 determines the sine wave within the range on the time axis provided in the oscilloscope device 300. All the times when the voltage level of the wave signal reaches the threshold voltage are measured. At this time, after measuring the time when the sine wave signal reaches the threshold voltage in the rising (or falling) state of the sine wave signal, the sine wave signal reaches the threshold voltage in the rising (or falling) state By measuring the time of day, two measurement time series can be obtained from a single frequency setting.

Alternatively, the trigger voltage of the oscilloscope device 300 is changed by measuring all the times when the voltage level of the sine wave signal reaches the threshold voltage within the range on the time axis provided in the oscilloscope device 300. By repeating, a plurality of measurement time series can be obtained from a single frequency setting.

Alternatively, the measurement of all times when the voltage level of the sine wave signal reaches the threshold voltage within the range on the time axis provided in the oscilloscope device 300 is repeated by changing the threshold voltage. Thus, it is possible to obtain a plurality of measurement time series from a single frequency setting.

Alternatively, a plurality of measurement time series can be obtained from a single frequency setting by executing the above three methods in combination.

The step S19 is the steps S16 to S1.
8 is executed for each measurement time series obtained. That is, in step S19, the measurement time series are t ₀ , t ₁ , ..., T _n-1 , t _n (t ₀ <t ₁ <... <
When t _n-1 <t _n ), time t _k (k = 1, 2,
, N) relative time axis error e from time t ₀
Calculate _k . Similar to the first embodiment, e _k = t _k −t
_{From 0} −k × T (k = 1, 2, ..., N), measurement time t
Time axis error e _k from ₀ , t _k and the set period T of the sine wave signal
Ask for.

In step S20, when the absolute error on the time axis from the origin at time t _k is E _k , E
E _k is calculated by assuming that the averaged value of _k over all k (k = 0, 1, ..., N) results in an equal value C at all frequency settings of the sinusoidal signal. Similarly to the second embodiment, the absolute error E _k of the time axis from the origin at time t _k (k = 0, 1, ..., N) is

[0068]

[Equation 7]

It is calculated by

In step S21, the microprocessor 7 causes the error memory 6C to hold the time axis error E _k calculated in step S20.

By performing the above operation, the plurality of measurement time series t ₀ , t ₁ , t ₁ can be obtained without changing the frequency setting of the sine wave signal applied to the oscilloscope device 300.
, T _n-1 , t _n are obtained, and times t ₀ , t ₁ , ..., t are obtained.
Absolute errors E ₀ , E ₁ , ..., On the time axis at _n−1 and t _n
The function of obtaining E _n-1 and E _n is realized. As a result, it is possible to increase the number of times on the time axis for measuring the time axis error, as compared with the first embodiment.

(Embodiment 4) FIG. 7 is a flow chart of a program showing an embodiment of software for executing the function of calibrating the time base error of the oscilloscope device itself in the present invention. This program is program memory 6A
Stored in. This embodiment will be described with reference to FIG.

In step S22, the channel input signal is sampled, A / D converted, and the result is written in the data memory 6B. The channel input signal is sampled by the sampler 4 at the sampling time generated by the sampling time generation circuit 2, digitized by the A / D converter 5, and the microprocessor 7
Is written in the data memory 6B.

In step S23, the time axis error at the sampling time is interpolated. The measured value of the time axis error held in the non-volatile memory as the error memory is
At times t ₀ , t ₁ , ..., T _n-1 , t _n (t ₀ <t ₁ <... <
At t _n-1 <t _n ) respectively, E ₀ , E ₁ , ...,
_Let E _n−1 and E _n . At this time, t ₀ ≦ t ≦ t _n
Then, the time axis error at the sampling time t is calculated by interpolation. For example, when linear interpolation is used, the time axis error E (t) at the sampling time t is t _k-1 ≦
For _{k such} that t ≦ t _k ,

[0075]

[Equation 8]

It is calculated by

In step S24, the voltage of the input signal is displayed at the position of the time when the time axis error E (t) calculated by interpolation is subtracted from the sampling time. The voltage level of the input signal at the sampling time t is V (t)
, The time t−E (t) is displayed on the display 10.
The microprocessor 7 writes the graphic data to the frame memory 9 so that the voltage level of the input signal at is indicated as V (t).

By performing the above operation for all t required for graphic output, it is possible to display the measurement result in which the time base error is calibrated on the display 10 of the oscilloscope device 300. The time base error of can be calibrated.

(Embodiment 5) FIG. 8 is a flow chart of a program showing an embodiment of software for executing the function of calibrating the time base error of the oscilloscope device itself in the present invention. This program is program memory 6A
Stored in. This embodiment will be described with reference to FIG.

In step S25, a function form representing the time axis error is obtained for each factor that causes the time axis error of the digital sampling oscilloscope device 300.
For example, the time base error of the oscilloscope device 300 is
It can be classified into (A) an error caused by a deviation of a frequency standard incorporated in the oscilloscope device for generating the sampling timing, and (B) an error caused by an analog delay circuit generating a timing less than the cycle of the frequency standard. At this time, the time axis error due to (A) is
For each period T of this frequency standard, a step function that increases stepwise by a fixed amount is used to express the time axis error due to (B) as
It is represented by a sine wave function whose period is T.

Step S26 is executed after the measurement of the time axis error, and represents the time axis error as the sum of all the factors of the function form obtained in step S25, but the weight is the measured value of the time axis error. Then, an approximate function representing the time axis error is derived. As a specific example, step S2
This will be described by using the function illustrated in FIG. At this time, the approximate function E (t) representing the time base error of the oscilloscope device is

[0082]

Equation 9] _{E (t) = C 0 +} C 1 × [t / T] × T + C 2 '× sin (2π × t / T + θ) = C 0 + C 1 × [t / T] × T + C 2 × sin (2π × t / T) + C ₃ × cos (2π × t / T) (C ₀ , C ₁ , C ₂ ′, C ₂ , C ₃ are the weights of each error, and θ is the time axis according to (B) The phase [N] of the sine wave function that represents the error is the maximum integer that does not exceed N). The measured values of the time axis error held in the non-volatile memory are times t ₀ , t ₁ , ..., T _n-1 , t _n (t ₀ <t ₁
<... <t _n-1 <t _n ) respectively, E ₀ , E
_1, ..., and is E _n-1, E _n. At this time, the square of the difference between the measured value E _K (k = 0, 1, ..., N) of the time axis error and the magnitude E (t _k ) obtained from the approximation function, {E (t _k ).
C ₀ , C that minimizes the sum of −E _k } ² for all k
₁ , C ₂ , C ₃ can be obtained by the following formula using regression analysis.

[0083]

[Equation 10]

By solving the above equation, the weight of each error is determined, and the approximate function E (t) representing the time base error of the oscilloscope device is derived. The derived approximation function is held in the non-volatile memory.

In step S27, the channel input signal is sampled, A / D converted, and the result is written in the data memory 6B. The channel input signal is sampled by the sampler 4 at the sampling time generated by the sampling time generation circuit 2, digitized by the A / D converter 5, and the microprocessor 7
Is written in the data memory 6B.

In step S28, the time axis error at the sampling time t is calculated from the approximation function derived in step S26.

In step S29, the voltage of the input signal is displayed at the time position where the time axis error E (t) calculated by the interpolation is subtracted from the sampling time. The voltage level of the input signal at the sampling time t is V (t)
, The microprocessor 7 writes the graphic data in the frame memory 9 so that the voltage level of the input signal at the time t−E (t) is displayed on the display as V (t).

By performing the above operation for all t required for graphic output, it is possible to display the measurement result in which the time base error is calibrated on the display 10 of the oscilloscope device 300.

(Embodiment 6) Next, the frequency setting of the sine wave signal applied to the oscilloscope device is changed, and the time axis error of the oscilloscope device itself is measured at a plurality of times on the time axis. An example will be described.

Here, in the second embodiment, the measurement range S of the time base error on the time base of the oscilloscope device 300 is the period T ₀ of the frequency standard 3 for generating the sampling time incorporated in the oscilloscope device 300. Is p times (p is an integer).

In the second embodiment, the frequencies of the sine wave signals applied to the oscilloscope device 300 are relatively prime to the integer p, and a plurality of m (m> 1) different integers q ₁ and q larger than 1 which are different from each other. ₂ , ..., q _m , a value obtained by dividing this integer by the range S in which the time base error measurement is performed, q ₁ /
Let S, q ₂ / S, ..., Q _m / S.

In the second embodiment, when the absolute error on the time axis from the origin at time t _k is E _K , E _k is over all k (k = 0, 1, ..., N) in the measurement time series. It is assumed that the averaged values will be equal for all frequency settings of the sinusoidal signal. However, this assumption may not hold when the time axis error that is repeated in the same cycle as the frequency standard cycle caused by the nonlinear error of the alnalog delay circuit is dominant and the frequency setting of the sine wave signal is low. is there. For example, when the frequency of the sine wave signal is the same as the frequency of the frequency standard, only the time when the time axis error is large (small) repeated in the same cycle as the cycle of the frequency standard may be measured in the measurement series. Because.

However, when the time axis error measurement range and the sine wave signal frequency are set by the above method, when the sine wave signal frequency is q _k / S, the period T of the frequency standard is set.
_For all q _k times _{obtained by} equally dividing ₀ by q _k , the time axis error repeated in the same cycle as the cycle of the frequency standard is measured. As a result, the assumption in Example 2 is established.

(Embodiment 7) FIG. 9 shows an embodiment of the present invention in which the time base error of the oscilloscope device itself is measured at a plurality of times on the time base.

In the first, second, third and sixth embodiments, when the sine wave signal generator 100 is connected to the oscilloscope device 300, as shown in FIG.
A sine wave signal having only a single frequency component generated from 00 is branched by a divider 200, one is applied to a trigger terminal of an oscilloscope device 300 for measuring a time base error, and the other is AC coupled via a capacitor 400. Then, it is applied to the channel input terminal of the oscilloscope device 300.

In Examples 1, 2, 3 and 6, when measuring the time when the voltage level of the sine wave signal reaches a certain threshold voltage within the range on the time axis of the oscilloscope device 300, the oscilloscope device 300 is used. Is set to 0V, and the threshold voltage is set to 0V.

The time derivative of the sine wave signal, that is, the slew rate is the smallest at the center voltage level of the sine wave signal. Therefore, when measuring the time when the voltage level of the sine wave signal becomes the center voltage level, the slope of the sine wave signal at the measurement time becomes the maximum, so the timing measurement error caused by noise or jitter of the sine wave signal becomes the minimum. . When a sine wave signal is applied to the oscilloscope device 300 by AC coupling with the capacitor 400, 0 V is the center voltage level of the sine wave signal. Therefore, when the threshold voltage of the sine wave signal is set to 0V, the influence of noise and jitter of the sine wave signal on the time measurement is minimized.

The voltage axis and trigger level setting of the oscilloscope device 300 include gain and offset errors. However, these errors are caused by setting the trigger voltage of the oscilloscope device to 0V and the threshold voltage to 0V.
When set to, it does not affect the time measurement accuracy.

As a result, a sine wave signal is applied to the oscilloscope device by AC coupling, the trigger voltage of the oscilloscope device is set to 0V, and the threshold voltage of the sine wave signal is set to 0.
When set to V, the measurement accuracy of the time in the first, second, third, and sixth embodiments can be improved, and the measurement accuracy of the time axis error can be improved.

[0100]

As described above, according to the present invention,
Connect the sine wave signal generator to the oscilloscope device and start when the key input to start the time base error measurement is started.Measure the period of the sine wave signal on the oscilloscope device and measure the period and the sine wave signal. The time axis error of the oscilloscope device is measured by calculating from the difference with the period of the signal, and the time axis error of the oscilloscope device is calibrated using the measurement result of the time axis error measurement performed as described above. By displaying the input voltage on the display using the calibrated time axis error, it is possible to provide a digital sampling oscilloscope device having a time axis error measuring function and a calibrating function. For example, the time axis error measuring function and the calibration function of the present invention can be applied to the band 20 GH.
z, Time axis error is measured using a synthesizer with an accuracy of 10 ^-8 , and the time axis error is calibrated by using a digital sampling oscilloscope device with a time axis error of 10 picoseconds. It is possible to realize an oscilloscope device having axis accuracy.

Furthermore, by using the time axis error measuring method and the calibration method according to the present invention in combination with the existing digital sampling oscilloscope device, the above-mentioned effects can be obtained, and thus the oscilloscope with poor time axis accuracy can be obtained. The device can be used to improve the measurement accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an oscilloscope device of the present invention.

FIG. 2 is a flowchart showing an embodiment of software for executing the function of measuring the time base error of the oscilloscope device of the present invention.

FIG. 3 is a connection diagram showing an example of a mode in which a sine wave signal source is connected to the oscilloscope device of the present invention.

FIG. 4 is an explanatory diagram of an example of measuring the period of a sine wave signal over a measurement range of a time axis error in the present invention.

FIG. 5 is a flow chart showing an embodiment of software for executing the function of measuring the time base error of the oscilloscope device using the sine wave signals of a plurality of frequencies of the oscilloscope device of the present invention.

FIG. 6 is a flowchart showing an embodiment of software for executing the function of measuring the time base error of the oscilloscope device of the present invention.

FIG. 7 is a flowchart showing an embodiment of software for executing the function of calibrating the time base error of the oscilloscope device of the present invention.

FIG. 8 is a flow chart showing an embodiment of software for executing the function of calibrating the time base error of the oscilloscope device of the present invention.

FIG. 9 is a connection diagram showing another embodiment of the mode in which a sine wave signal source is connected to the oscilloscope device of the present invention.

[Explanation of symbols]

 1 Trigger circuit 2 Sampling time generation circuit 3 Frequency standard 4 Sampler 5 A / D converter 6 Memory 6A Program memory 6B Data memory 6C Error memory 7 Microprocessor 8 Input / output circuit 9 Frame memory 10 Display device 11 D / A converter 12 Bus 100 Sine wave signal generator 200 Divider 300 Oscilloscope device 400 Capacitor

Claims (14)

[Claims] 1. A channel input terminal for receiving a channel input, a trigger terminal for receiving a trigger input, a sine wave signal having only a single frequency component is supplied as a measurement standard to the channel input terminal and the trigger terminal, and the sine signal is supplied. The time when the voltage level of the wave signal reaches the predetermined threshold voltage in the rising or falling state, a means for measuring all over a predetermined range on the time axis on the display surface of the oscilloscope device to obtain a measurement time series, The measurement time series are represented by t ₀ , t ₁ , ..., T _n-1 , t _n (t
₀ <t ₁ <... <t _n-1 <t _n ) and the difference between adjacent measurement times, T _k = t _k −t _k−1 (k = 1, 2,
, N) as the cycle measurement value, the cycle measurement value T _k
Wherein a difference between the period T of the sine wave signal, means for determining a relative time base error .DELTA.e _k from time t _k-1 at time t _k, the time relative to the time t ₀ at time t _k and Axis error e
The _k, comprises a means for determining from the sum from .DELTA.e ₁ to .DELTA.e _k, digital sampling oscilloscope apparatus being characterized in that so as to measure the time base error. 2. A channel input terminal for receiving a channel input, a trigger terminal for receiving a trigger input, and a sine wave signal having only a single frequency component is supplied to the channel input terminal and the trigger terminal as a measurement standard, To obtain the measurement time series by measuring all the time when the voltage level of the wave signal reaches the predetermined threshold voltage in the rising or falling state over the predetermined range on the time axis on the display surface of the oscilloscope device. Means for repeatedly executing a plurality of times by changing the frequency setting of the sine wave signal, and one of the measurement time series are t ₀ , t ₁ , ..., T _n-1 ,
t _n (t ₀ <t ₁ <... <t _n-1 <t _n ) and the difference between adjacent measurement times, T _k = t _k −t _k−1 (k =
1, 2, ..., N) as the cycle measurement values, the difference between the cycle measurement value T _k and the cycle T of the sine wave signal is calculated as
relative time base error .DELTA.e _k from time t _k-1 in the _k
And a relative time axis error e from time t _{0 at} time t _k
a _k, to ask than the sum of from Δe ₁ to Δe _k,
Means for performing for all measurement time series, the time t _k at all the absolute error E _k of the time axis from the origin k (k = 0,1, ..., n) value averaged over the,
Assuming equal for each measurement time series, the absolute error E ₀ of the time axis from the origin at time t ₀
Is calculated for all measurement time series, and the absolute error E _k of the time axis from the origin at time t _k is calculated from the sum of E ₀ and e _k for all k of all measurement time series. A digital sampling oscilloscope device, characterized in that the time axis error is measured by means of executing the above. 3. A channel input terminal for receiving a channel input.
, A trigger terminal that receives the trigger input, and a sine wave signal that has only a single frequency component as the measurement standard.
Supply to the channel input terminal and the trigger terminal
The voltage level of the sine wave signal is rising.
The time to reach the constant threshold voltage is
Measure all over a predetermined range on the time axis equipped with the device,
Furthermore, the time to reach the predetermined threshold in the falling state
Measure all over the specified range and
Both the measurement time series and the measurement time series in the falling state
And that the voltage level of the sine wave signal is predetermined
The time to reach the threshold voltage is
Measure all over the specified range on the display screen
Change the threshold voltage to obtain the measurement time series
To obtain multiple measurement time series.
And a sine wave by performing at least one of
Obtain multiple measurement time series from a single frequency setting of the signal
Means and one of the plurality of measurement time series,₀ , T₁ , ..., t
_n-1 , T_n (T₀ <T₁ <... <t_n-1 <T_n ) And next to
The difference between the measurement times of each contact, T_k = T_k -T_k-1 
When (k = 1, 2, ..., N) is the measured value of the cycle,
Relevant measurement value T _k And apply it to the oscilloscope device
The difference from the period T of the sine wave signal is_kTime in
t_k-1 Relative time axis error Δe from_k Asking for
Dan and time t_k At time t₀ Relative time axis error e from
_k Is Δe₁ To Δe_k To obtain from the sum of
Means for executing all measurement time series, and time t_k Error E on the time axis from the origin at_k The whole
Values averaged over all k (k = 0, 1, ..., N) are
Assuming it is equal for each measurement time series
At time t₀ Error E on the time axis from the origin at₀ 
And calculate E₀ And e_k From the sum of time t_k Origin of
Absolute error E on the time axis from_k For all k
A way to do things for all measurement time series
The feature is that the time axis error is measured with
Digital sampling oscilloscope device to be used. 4. A means for sampling an input signal at a predetermined sampling time for A / D conversion, a data memory for storing the digital signal and sampling time obtained by the A / D conversion, and a graphic data store. A frame memory, a digital signal data necessary for display is taken out from the data memory, converted into graphic data and written into the frame memory, a means for converting the graphic data held in the frame memory into an analog signal, A display that displays an analog signal, an error memory that stores the time base error measured in any one of claims 1 to 3, and a time base that stores the time base error at the sampling time in the error memory. Means to interpolate based on error measurement The time axis error that the oscilloscope device itself has is equipped with a means for storing the time obtained by subtracting the time axis error stopped by the interpolation from the sampling time in the data memory as the sampling time after the time axis error calibration. A digital sampling oscilloscope device characterized in that it is calibrated. 5. A means for sampling an input signal at a predetermined sampling time and performing A / D conversion, a data memory for storing the digital signal and sampling time obtained by the A / D conversion, and a graphic data store. A frame memory, a digital signal data necessary for display is taken out from the data memory, converted into graphic data and written into the frame memory, a means for converting the graphic data held in the frame memory into an analog signal, A display that displays an analog signal, an error memory that stores the time base error measured in any one of claims 1 to 3, and a factor that causes the time base error of the oscilloscope device. The functional form of the time axis error The magnitude of the time-axis error of the oscilloscope device is obtained and expressed as a sum of all function types with unique weights, and the respective weights of the time-axis error stored in the error memory are represented. Means for deriving an approximation function representing a time axis error by obtaining the measurement result, an approximation function memory holding the approximation function calculated thereby, and a time axis error at the sampling time are held in the approximation function memory. And a means for storing the time obtained by subtracting the calculated time axis error from the sampling time in the data memory as the sampling time after time axis error calibration, A digital sampling oscilloscope device characterized in that the time base error of the oscilloscope device is calibrated. . 6. The digital sampling oscilloscope device according to claim 2, wherein the range (S) for measuring the time axis error is p times the period (T ₀ ) of the frequency standard for sampling time generation incorporated in the oscilloscope device. (P is an integer) Range (T ₀ ×
p), and a plurality of m (m> 1) different integers q greater than 1 that are coprime to the integer p for the frequency of the sine wave signal.
_{From 1} , q ₂ , ..., q _m , q ₁ / S, q ₂ / S, ..., q
A digital sampling oscilloscope device comprising means for determining _m / S and configured to measure a time base error. 7. The digital sampling oscilloscope device according to claim 1, 2, 3 or 6, wherein the sine wave signal as the measurement standard is supplied to the channel input terminal by AC coupling, and the trigger level voltage of the oscilloscope device is changed. A digital sampling oscilloscope characterized by being set to 0 V and measuring the time when the voltage level of the sine wave signal reaches 0 V over the predetermined range on the time axis on the display surface of the oscilloscope device. apparatus. 8. The time axis error of the oscilloscope device is calibrated by measuring the time axis error of the oscilloscope device itself and correcting the waveform data measured by the oscilloscope device using the measurement result of the time axis error. In the method, a first step of applying a sinusoidal signal of a predetermined frequency having only a single frequency component to the oscilloscope device, and a step of applying the sinusoidal signal to the oscilloscope device in the range on the time axis on the display surface. The second step of measuring the time when the voltage level reaches a certain set voltage as data representing the time position on the display surface, and the measurement time series are t ₀ , t ₁ , ..., T _n-1 , t _n
(T ₀ <t ₁ <... <t _n-1 <t _n ) and the difference between adjacent measurement times, T _k = t _k −t _k−1 (k = 1, 2, ..., N).
When the the measured value of the period, relative time axis of a difference between the period T of the sine wave signal applied to the oscilloscope device and the measurement value T _k of period circumferential, from time t _k-1 at time t _k The oscilloscope includes a third step of obtaining an error Δe _k and a fourth step of obtaining a relative time axis error e _k from time t _{0 at} time t _k from the sum total of Δe ₁ to Δe _k A time axis error measuring method for an oscilloscope device, characterized by measuring the time axis error of the device itself. 9. The time axis error measuring method according to claim 8, wherein a range obtained by multiplying a period T ₀ of a frequency standard built in the oscilloscope device and generating sampling timing by p (p is an integer) is set as a time axis. Error measurement range S (= T
₀ x p), a fifth step of setting on the time axis on the display surface of the oscilloscope device, and an integer p that is coprime to the integer p and is greater than 1 of m (m> 1) different from each other. _1, q _2, ..., a q _m, the frequency of the sine wave _{signal, q 1 / S, q 2} / S, ..., q m / S
2. The sixth step of determining in the above step, and for each of the m frequencies determined in the sixth step, over the range on the time axis of the oscilloscope device determined in the fifth step. The seventh step of obtaining the relative time axis error e _k from the time t _{0 at} the time t _k by the method, and the absolute error E _K of the time axis from the origin at the time t _k to all k (k = 1 , 2, ..., N), the eighth step of calculating the absolute error E ₀ on the time axis at time t ₀ under the assumption that the values averaged over all the frequency settings of the sine wave signal are equal. A ninth step of obtaining the absolute error E _K of the time axis at time t _k from the sum of E ₀ and e _k for all k, and measuring the time axis error of the oscilloscope device. Characteristic Oshirosuko Method for measuring the time base error of a tracking device. 10. The time axis error measuring method according to claim 8 or 9, wherein the time at which the voltage level of the sine wave signal reaches a certain set voltage in the second step is measured on the display surface of the oscilloscope device. In, a method for measuring both the time when the voltage level of the sine wave signal reaches the set voltage at the time of rising and the time when the voltage reaches the set voltage, changing the trigger voltage level of the oscilloscope device, a method of repeating the measurement, And a method of repeating the measurement by changing the set voltage for measuring the period of the sine wave signal, and using a plurality of measurement times t ₀ , t from a single frequency of the sine wave signal. ₁ , ..., t _n-1 ,
t _n (t ₀ <t ₁ <... <t _n-1 <t _n ) is obtained, and by the third and fourth steps, for each measurement time, from time t _{0 at} time t _k The relative time axis error e _k is measured, and the time axis error of the oscilloscope device is measured by obtaining the absolute error E _k of the time axis at the time t _k in the eighth and ninth steps. A method for measuring a time base error of an oscilloscope device, characterized by: 11. The time axis error measuring method according to claim 8, 9 or 10, wherein in the first step, a sine wave signal having only the single frequency component is AC-coupled to the oscilloscope device to be calibrated. In the second step, the time at which the voltage level of the sine wave signal reaches 0V is read on the display surface of the oscilloscope device in the range on the time axis on the display surface of the oscilloscope device to be calibrated. A method for measuring a time base error of an oscilloscope device, which is characterized in that 12. A first step of measuring a time base error of the oscilloscope device itself, a second step of storing a measurement result of the time base error in an error memory, and waveform data measured by the oscilloscope device. With respect to the above time, the third step of interpolating the magnitude of the time axis error at that time from the measurement result of the time axis error, and the time axis error obtained by the interpolation are subtracted from the time and calibrated. A fourth step of performing the obtaining of the obtained time over all the times on the waveform data, and a fifth step of displaying the waveform data at the position of the calibrated time on the display of the oscilloscope device. A method for calibrating a time axis error of an oscilloscope device, which is characterized by comprising: 13. A first step of measuring a time-axis error of the oscilloscope device itself, a second step of storing a measurement result of the time-axis error in an error memory, and a step of measuring the time-axis error from the measurement result of the time-axis error. A third step of calculating an approximate function representing a time base error of the oscilloscope device, and a time on the waveform data measured by the oscilloscope device, the magnitude of the time base error at the time is calculated from the approximate function. A fourth step of calculating, a fifth step of subtracting the calculated time axis error from the time to obtain a calibrated time over all the times on the waveform data, and the oscilloscope device And a sixth step of displaying the waveform data at the position of the calibrated time on the display. Time base error correcting method Coop device. 14. The time axis error calibration method according to claim 13, wherein, for each factor that causes a time axis error of the oscilloscope device, a seventh step of obtaining a function representing the magnitude of the time axis error due to the factor. , An eighth step of obtaining a time axis error as a sum of all the factors obtained by weighting the obtained function and using a regression analysis from the measured values of the time axis error, A method for calibrating a time axis error of an oscilloscope device, comprising calculating the approximate function that represents a time axis error of the oscilloscope device.