JPH0663831B2 - Optical emission measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a light emission measuring device for measuring a change in light emitted from a light source when the intensity of the light emitted from the light source fluctuates. Regarding

(Prior Art) For example, when communication is performed between vessels using an optical signal, a means for changing the emission intensity of a lamp used as a light source and transmitting / receiving as an optical pulse signal can be considered.

A discharge lamp having a large light output is often used as a lamp used as a light source. This type of discharge lamp is always kept in a lighting state in order to maintain discharge, and therefore maintains a predetermined minimum light emitting state. If this minimum emission intensity is called a base component, in order to emit pulsed light as a signal, it is necessary to superimpose on this base component to emit a pulsed optical signal with a large emission intensity. That is,
The light source emits light of the base component and the signal component, and functions as a signal due to the fluctuation of the signal component in the light component.

It is necessary to measure the signal component of the light emitted from such a lamp.

In the case of measuring the light intensity, a spectrophotometer has been often used to perform this spectroscopically.

FIG. 6 shows an example of a conventional spectrometer.

In FIG. 6, 1 is a discharge lamp as a light source, 2 is a spectroscope for receiving light emitted from the discharge lamp 1 and splitting it into light of a predetermined wavelength, 3 is the intensity of the light split by the spectroscope 2. To an electric signal, 4 is a preamplifier for converting the electric signal of the photoelectric detector into a data processable strength, 60 is a DC integrator, and 61 is an output device composed of a personal computer or the like. .

In such a spectroscopic measurement device, the periodically varying measurement light emitted from the discharge lamp 1 as a light source passes through the spectroscope 2 to select light having a predetermined wavelength, that is, monochromatic light, by a prism or the like. The monochromatic light is converted into an electric signal, for example, a voltage by the photoelectric detector 3.

This electric signal is amplified by the preamplifier 4 and the direct current integrator 60
To process.

The voltage waveform output by the preamplifier 4 is a waveform in which the signal component b is superimposed on the base component a as shown in FIG. 7A if the temporal response of this amplifier is sufficiently fast.

In the DC integrator 60, as shown in FIG. 7B, a continuous amount of voltage is integrated at a preset sampling time t, and this integrated value is output from the output device 61 for display and signal processing.

However, in the case of such a spectroscopic measuring device, the direct current integrator 60 measures the optical output emitted from the light source as a direct current in which the signal component b is superimposed on the base component a.

Therefore, it is not possible to measure only the signal component b having the AC characteristic, and the base component a occupies most of the output value, which makes it difficult to measure the signal component as a fluctuation component with high accuracy.

On the other hand, as another conventional method, the AC integrator 80 shown in FIG. 8 may be used.

The AC integrator 80 cuts the base component of the input superimposed waveform, AC-amplifies only the signal component (AC component), and integrates this.

The spectrophotometer of FIG. 8 uses an AC integrator 80 instead of the DC integrator 60 of the device shown in FIG. 6 and includes a chopper device 90. This spectroscopic measuring instrument takes in the waveform of the optical output as shown in FIG. 9A by the interruption of light by the chopper device 90 and converts it into a large AC signal as shown in FIG. 9B inside the AC integrator 80, The total power including the base component and the signal component is measured.

However, also in this case, it is not possible to measure only the signal component b having the AC characteristic, and the base component a occupies most of the output value. Therefore, it is difficult to measure the signal component with high accuracy even as a fluctuation component. is there.

Further, as another conventional method, an AC integrator 80 is used in place of the DC integrator 60 of the device shown in FIG.
However, there is one in which the chopper device 90 is not used, and this is shown in FIG.

In the case of the spectroscopic measurement device shown in FIG. 10, the first component in which the signal component b is superimposed on the base component a output by the preamplifier 4 is used.
The waveform shown in FIG. 1A is converted into a waveform shown in FIG.
As shown in, only the signal component (AC component) is extracted as an AC waveform, and this is amplified and integrated.

In this case, the signal component b can be obtained in the form of an average value or an effective value because it is output as an alternating current in the usual case.

However, this result is also unsuitable for use, as it will be a value that does not satisfy our measurement purpose as described later.

(Problems to be Solved by the Invention) That is, the AC integrator 80 shown in FIG.
The base component a of the superimposed waveform as shown in FIG. A is cut out to extract only the signal component b. In this case, FIG.
As shown in, the zero level is shifted to a position where the area of the signal component b is equally divided into upper and lower parts.

As described above, in the case of the method of shifting the zero level by the AC integrator 80 to the position where the area of the signal component b is equally divided, the hatched area in FIG. 11B is integrated. The average value of the component b will be measured.

That is, the actually desired integral value is the area of the shaded area b in FIG.
Since the shaded area in FIG. 1B is integrated, FIG.
The value becomes half of the shaded area, and it is measured as an average value.

Therefore, if the measured value indicated by the diagonal lines in FIG. 11B is doubled, the signal amount can be obtained in the case of the triangular waveform shown in the figure, but in this case, a calculation process for doubling is required.

Moreover, such a measurement can be performed when the signal component b has a vertically symmetrical waveform such as the triangular wave or the sine wave, but when the waveform of the signal component is asymmetric, it is not doubled and therefore accurate. The value cannot be calculated.

That is, for example, when the waveform of the signal component is a peak waveform as shown in FIG. 12A, when the AC integrator 80 shown in FIG. 10 is used, only the signal component b of the superimposed waveform is extracted and zero. Since the level is shifted to a position where the area of the signal component is equally divided into upper and lower parts, the integrated value becomes a shaded area in FIG. 12B.

On the other hand, for example, in the case where the waveform of the signal component is a trapezoidal waveform which is symmetrical to the above-mentioned peak waveform as shown in FIG.
The integrated value obtained by the AC integrator 80 is in the shaded area in FIG. 13B.

That is, the integrated value of FIG. 12B and the integrated value of FIG. 13B are equal.

However, in the case of FIG. 12, the true integrated value of the signal component to be measured is the shaded area in FIG. 12C, whereas in the case of FIG. 13, the true integrated value of the signal component to be measured. Is an area indicated by diagonal lines in FIG. 13C.

However, when the conventional AC integrator 80 as described above is used, the signal component waveform of FIG. 12 and the signal component waveform of FIG. 13 cannot be distinguished and measured, and there is a problem that both are measured as the same value. is there.

The present invention has been made under such circumstances, and an object of the present invention is to make it possible to measure a signal component with high accuracy and to accurately measure even a waveform of an asymmetrical signal component. It is intended to provide an optical emission measurement device.

[Structure of the Invention] (Means for Solving the Problems) The first aspect of the present invention is that a photoelectric conversion device receives light emitted from a light source that emits light in which a base component that does not change and a signal component that changes are superimposed. However, this photoelectric conversion device emits a waveform electric signal in which the base component and the signal component are superposed in accordance with the intensity of light, and the waveform electric signal is data-processed by a signal processing device to change the fluctuating light amount to an electric signal. In the optical radiation measuring device for outputting as, the signal processing device extracts only the signal component from the waveform in which the base component and the signal component are superimposed and adjusts the zero level to the lowest level of the signal component, and the zero signal. It is characterized in that it is provided with an integrating means for integrating the area of the signal component above the level and an output means for outputting the integrated value.

A second aspect of the present invention is provided with a synchronization signal generator that photoelectrically detects the fluctuation of the measurement light and outputs a signal to the integrating means as a signal for designating the start of integration of the integrating means. It is characterized by

(Operation) According to the first aspect of the present invention, the signal processing device takes out only the signal component from the waveform in which the base component and the signal component are superimposed, and adjusts the zero level to the lowest level of the signal component, and the above zero. Since the integrating means for integrating the area of the signal component equal to or higher than the level is provided, only the signal component is integrated as the variation amount, and the measurement according to the purpose becomes possible.

Further, according to the second aspect of the present invention, since the integration can be started based on the signal given from the synchronization signal generator, the integration start timing can be synchronized with the fluctuation of the optical output, and the measurement accuracy is improved.

(Example) Hereinafter, the present invention will be described based on a first example applied to the spectroscopic measurement device shown in FIGS. 1 and 2.

In FIG. 1, 1 is a discharge lamp as a light source, 2 is a spectroscope for splitting the light emitted from the discharge lamp 1 into light of a predetermined wavelength, 3 is an electric intensity of the light split by the spectroscope 2. A photoelectric detector 4 for converting into a signal is a preamplifier 4 for converting an electric signal of the photoelectric detector into a data processable intensity, and these constitutions are shown in FIG. 6 and FIG. It may be similar to the case of the measuring device.

Reference numeral 10 is a signal processing device applied to the present invention, which processes the waveform electric signal output from the preamplifier 4 and outputs the fluctuating light amount as an electric signal. This signal processing device 1
In the case of the present embodiment, 0 is composed of a clipper type integrator 11 and an output device 12 such as a personal computer.

The clipper type integrator 11 is provided with an operational amplifier, etc., though not shown, and a zero level is set to the lowest level of the signal component b from the signal waveform in which the base component a and the signal component b output from the preamplifier 4 are superimposed. It has a clipper function for adjusting to, and an integration function for integrating the area of the signal component above the zero level.

Further, in the present embodiment, a synchronization signal generator 15 is provided, and this synchronization signal generator 15 has an optical sensor 16 for directly detecting the light emitted from the light source 1, and this optical sensor 16.
Is composed of a signal transmitter 17 which emits a synchronizing signal such as a pulse signal when the fluctuation of the measuring light is captured.
The synchronization signal generated from the signal oscillator 17 is input to the clipper type integrator 11 and used as a signal for designating the start time of integration.

The integration end timing is determined by the clipper type integrator 11
Instruct.

The operation of the embodiment having such a configuration will be described.

The measuring light emitted from the discharge lamp 1 as a light source is a spectroscope 2
By passing through, only monochromatic light having a predetermined wavelength is selectively transmitted by a prism or the like, and the monochromatic light is converted into an electric signal, that is, a voltage by the photoelectric detector 3. This electric signal is amplified by the preamplifier 4 and sent to the signal processing device 10.

The voltage waveform output from the preamplifier 4 is a waveform in which the signal component b is superimposed on the base component a as shown in FIG. 2A.

In the signal processing device 10, the clipper type integrator 11 has a second
Cut the base component a from the voltage waveform shown in FIG.
Only the signal component b is extracted.

The action at this time is to shift the zero level so as to match the minimum level of the signal component b, and this is performed by the clipper function.

On the other hand, the optical sensor 16 of the synchronization signal generator 15 is
Signal transmitter 1 when the fluctuation of the light emitted from the device is captured
7 issues a synchronizing signal such as a pulse signal, and this synchronizing signal is input to the clipper type integrator 11 to specify the start time of integration.

The clipper type integrator 11 performs integration from the start of this integration to the end of the integration designated by the clipper type integrator 11, that is, during the sampling time t.

This integral is a region of the signal component b above the zero level,
That is, the shaded area in FIG. 2B is integrated.

Such an integrated value is output as an electric signal from the output device 12 such as a personal computer and displayed.

In the measuring apparatus of such an embodiment, the zero level is shifted by the clipper function so as to match the minimum level of the signal component b, and the signal component b in the region above this zero level is integrated. It is possible to calculate an integral value according to the waveform of the signal component b, as indicated by the diagonal line.

Therefore, as compared with the case of measuring the average value shown in FIG. 11B, it is possible to obtain the actual measurement value according to the waveform of the signal component b, which is suitable for the measurement purpose.

Further, in the case of the waveforms shown in FIGS. 12 and 13, since the shaded areas are measured as shown in FIGS. 12C and 13C, respectively, it is necessary to distinguish these waveform signals. You can

In the first embodiment, the sync signal generator 15
Is composed of the optical sensor 16 and the signal transmitter 17, but the synchronizing signal generator 15 may be structured as in the second embodiment shown in FIG.

In the case of the second embodiment, the synchronization signal generator 15 is composed of a light source lighting power source 20, a step-down device 21, and a signal transmitter 17.

In this case, in order to change the light output as a normal optical signal, the voltage on the power supply side applied to the lamp 1 is changed. Therefore, if the fluctuation of the power supply voltage is examined, the fluctuation of the measurement light is detected as in the case of detecting the fluctuation. Become.

Therefore, the voltage of the light source lighting power supply 20 supplied to the lamp is detected, and the detected voltage is dropped by the step-down device 21,
The signal transmitter 17 detects the output fluctuation of the lamp 1.

As a result, the signal transmitter 17 outputs a pulse signal synchronizing signal, and this synchronizing signal is input to the clipper type integrator 11 to specify the start time of sampling time integration.

Further, the present invention can be implemented even with the configuration as in the third embodiment shown in FIG.

In the third embodiment, the signal processing device 10 of the present invention is separately configured by a clipper 31, an integrator 32, and an output device 33.

The clipper 31 cuts the base component a and outputs the signal component b.
Only the signal is extracted, and the zero level is shifted so as to match the minimum level of the signal component b. The integrator 32 integrates the signal component b above the zero level at a predetermined sampling time t. The output device 33 outputs the integrated value as a display or a processed signal.

In this way, even if the signal processing device 10 is configured for each function, the same operation as that of the first embodiment is achieved.

Further, the present invention can be implemented even with the configuration as the fourth embodiment shown in FIG. 5, and in the case of the fourth embodiment, the clipper means, the integrating means, and the output means are personal computers. It is designed to be processed by one computer such as.

Further, in the above embodiment, the case where the radiation amount of the light of the specific wavelength is measured using the spectroscope has been described, but the present invention is not limited to this, and is specified by using, for example, an interference film filter or a colored glass filter. It is also possible to measure by transmitting light in the wavelength range.

Further, the present invention may be applied to the case where the light emitted from the light source is directly received by the photoelectric detector for measurement.

Further, the signal component b is not limited to one that periodically changes,
Even if it fluctuates irregularly, it can be measured.

As described above, according to the first aspect of the present invention, only the signal component is extracted from the waveform in which the base component and the signal component are superposed, and the zero level is adjusted to the lowest level of the signal component. Since the area of the signal component above the zero level is integrated, the variation of the signal component is integrated, and even an asymmetrical signal component waveform can be measured separately and the measurement performance is improved. .

Further, according to the second aspect of the present invention, since the integration can be started based on the signal given from the synchronizing signal generator, the start time of the integration can be synchronized with the fluctuation of the optical output, and the timing setting is easy and high. Can be done with precision.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a spectroscopic measurement apparatus showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram of its waveform processing, A is a signal waveform before processing, and B is a waveform showing an integration range. FIG. 3 is a block diagram of a spectroscopic measurement apparatus showing a second embodiment of the present invention, FIG. 4 is a block diagram of a spectroscopic measurement apparatus showing a third embodiment of the present invention, and FIG. FIG. 6 is a block diagram of a spectroscopic measurement apparatus showing a fourth embodiment, FIG. 6 is a block diagram of a spectrophotometer using a conventional DC integrator, FIG. 7 is an explanatory diagram of its waveform processing, and A is before processing. Signal waveform, B is a waveform showing the range of integration, FIG. 8 is a spectroscopic measuring instrument using a conventional AC integrator, and is a configuration diagram when a chopper device is used, and FIG. 9 is an explanation of its waveform processing. It is a figure, A is a signal waveform before processing, B is a waveform which shows the range of integration, and FIG. 10 is a spectrometer using a conventional AC integrator. Thus, FIG. 11 is an explanatory view of the waveform processing when the chopper device is not used, A is a signal waveform before the processing and the object of the present invention, B is a waveform that can be measured by the device of FIG. 10, FIG. 12 is an explanatory diagram in the case of processing another signal waveform, where A is a signal waveform before processing, B is a waveform showing a conventional integration range, C is a required integration waveform, and FIG. It is explanatory drawing at the time of processing another signal waveform, A is a signal waveform before a process, B is a waveform which shows the range of the conventional integration, C is the waveform of the required integration. 1 ... Discharge lamp, 2 ... Spectrometer, 3 ... Photoelectric detector, 4 ...
... Preamplifier, 10 ... Signal processing device, 11 ... Clipper type integrator, 12 ... Output device, 15 ... Synchronous signal generator, 16 ... Optical sensor, 17 ... Signal transmitter, 31 ...
Clipper, 32 ... integrator, 33 ... output device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Yotsuyanagi 1-4-4 Mita, Minato-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (2)

[Claims] 1. A waveform in which light emitted from a light source that emits light in which a base component that does not change and a signal component that changes is received is received and the base component and the signal component are overlapped according to the intensity of the light. A photoelectric conversion device that emits an electric signal and a signal processing device that performs data processing on the waveform electric signal and outputs a fluctuating light quantity as an electric signal are provided. In the signal processing device, the base component and the signal component are superimposed. A clipper means for extracting only the signal component from the waveform and adjusting the zero level to the lowest level of the signal component, an integrating means for integrating the area of the signal component above the zero level, and an output means for outputting the integrated value are provided. A characteristic optical radiation measuring device. 2. A synchronizing signal generator for photoelectrically detecting a fluctuation of the measuring light and issuing a signal to the integrating means as a signal for designating the start time of integration of the integrating means. The optical radiation measuring device according to claim 1.