JPS5937467A - Optical measuring device - Google Patents

Abstract

PURPOSE:To obtain an accurate output which is reliable for a long period, by monitoring whether outputs of a light source and a photoelectric converter remain within specific ranges all the time, and performing switching to another optical system in case of abnormality. CONSTITUTION:Light from a light source 1A enters a photosensor 6 installed in an electric field through an optical fiber 3A photocoupler 4, and optical fiber 5, and is varied in intensity according to the quantity to e measured to illuminate the photoelectric converter 10A through an optical fiber 7, photocoupler 8, and optical fiber 9A. Then, a processing circuit 18 divides the AC component of the output appearing at a detection resistance 11A corresponding to the irradiation light by the output of a mean value circuit 16 to find a voltage as the quantity to be measured. On the other hand, when the voltage obtained by detecting the driving current of the light source 1 by a resistance 2A or the output of the mean value circuit 16 goes beyond the specific range, a window comparator 14 or 17 is activated to display abnormality on a display device 12 through an OR gate 20, and a relay coil 12 or 13 is energized to operate a light source 1B or photoelectric converter 10B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical measuring device that captures a quantity to be measured as an optical change and obtains an electrical output proportional to the quantity to be measured from the change.

Conventional optical measurement devices do not monitor abnormalities in the optical system (light source, optical transmission line, optical sensor, photoelectric converter, etc.), so even if the light source deteriorates and the output of the measurement device becomes abnormal, I didn't know it was abnormal. This was especially a problem when the output of this measuring device was used continuously all the time.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and it constantly monitors whether the output of the light source and the photoelectric converter is within a certain range, and also monitors whether or not the output of the light source and the photoelectric converter are within a certain range. Switch to other optical systems that are provided with multiple units,
The purpose is to provide accurate output that is reliable over the long term.

An embodiment of the present invention shown in the drawings will be described below. The figure is a configuration diagram showing an embodiment of the optical measuring device according to the present invention, where (IA) and (IB) are, for example, the first . Second light source, (2A).

(2B) is the first. Second light source (IA), (IB)
1. for detecting the drive current of. The second detection resistor, (
3A) and (3B) are the first. Second light source (IA), (IB
) for transmitting the light of the first and second optical fibers, (4
) is the first. Second optical fibers (3A), (3B) and third
The first optical coupler (6), which connects the optical fiber (5) to the third optical fiber (5), is installed, for example, in an electric field and changes the intensity of the incident light from the third optical fiber (5) according to the voltage that is the measured quantity. (7) is a fourth optical fiber for transmitting light emitted from the optical sensor (6); (8) is a fourth optical fiber (7) for transmitting light emitted from the optical sensor (6);
) and 5th. The second optical coupler (IOA) and (IOB) connecting the sixth optical fibers (9A) and (9B) are connected to the fifth optical fiber (IOA) and (IOB). The first optical fiber, which is a photodiode, for example, converts the light from the sixth optical fibers (9A) and (9B) into electrical signals. Second photoelectric converter, (11A).

(IIB) is the first. Second photoelectric converter (10A) t(
3rd to detect the output of IOB). Fourth detection resistor, (1
2A) and (12B) are the first relay coils (12
) is switched and connected from the solid line position to the dotted line position when energized. The contacts (13A) and (13B) @2 are connected to the third relay which is switched from the solid line position to the dotted line position when the second relay coil (13), which will be described later, is energized. The fourth contact point (14) is the first contact point. The output of the second detection resistor (2A), (2B) is the first
The first window comparator (15) generates an output when the voltage is outside a predetermined range of the first wind comparator (15), which becomes conductive when the output of the first (5) wind comparator (14) is applied, and excites the first relay coil (12). The transistor (16) is the third transistor. Fourth detection resistor (IIA)
, (IIB), an average value circuit that obtains the average value of the outputs of (IIB), (17
) is a second window comparator that produces an output when the output of the average value circuit (16) is outside a second predetermined range;
) is the third. Fourth detection resistor (11A), t(IIB
) is a processing circuit that generates an output proportional to the measured quantity, which is an electrician, for example, by the ratio of the AC component output of the output and the output of the average value circuit (16); (19) is a second window comparator (
17) conducts and the second relay coil (1
(3) is the second transistor that excites the first transistor; (20) is the first transistor;
Second window comparator (14).

(17) is an OR circuit that is energized and produces an output when at least one of them produces an output; (21) is an OR circuit (2
This is an indicator that is energized by the output of 0) and indicates that the device is abnormal.

Next, the operation will be explained. First light source (IA) (g
) emits brightness according to its driving current. Therefore, set ζf so that the drive current is constant.

Certain light propagates through the first optical fiber (3A), is coupled to the third optical fiber (5) by the first optical coupler (4), and enters the optical sensor (6). The optical sensor (6) is installed, for example, in an electric field, and emits the incident light from the third optical fiber (5) with the intensity changed depending on the voltage as the measured quantity.

As the optical sensor (6), for example, a polarizer, a photoelastic element,
An acceleration sensor composed of an analyzer or the like, which outputs a certain amount of incident light after modulating its brightness based on vibration acceleration, is used. The emitted light from the optical sensor (6) propagates through the fourth optical fiber (7), is coupled to the fifth optical fiber (9A) by the second optical coupler (8), and is connected to the first photoelectric converter. (I
OA) is irradiated. The first photoelectric converter (IOA) transmits a current corresponding to the irradiated light to the third detection resistor (IIA).
) to convert it into a voltage, and the average value of this voltage is determined by an average value circuit (16). Also, the ratio of the AC component of the voltage appearing at the third detection resistor (IIA) to this average value is:
Since the modulation degree in the optical sensor (6) is constant, the first
Deterioration of the light source (IA) of 1st and 3rd. 4th. Fifth optical fiber (3A), (5).

Even if the amount of light changes due to changes in propagation loss (7) and (9A), it remains constant. Therefore, in the processing circuit (18), the third
The alternating current component of the voltage appearing on the detection resistor (IIA) is divided by the average value determined by the average value circuit (16), so that the voltage, which is an accurate quantity to be measured, can always be determined.

Next, the first light source (IA) or the first photoelectric conversion! (I
OA) is disconnected or short-circuited, the output of the processing circuit (18) becomes an abnormal value. In addition, the first light source (IA) may deteriorate significantly, or the first light source (IA) may deteriorate significantly. Third. 4th. Fifth optical fiber (3A).

If the propagation loss becomes abnormally large in (5), (7), (9A), etc., the processing circuit (18) cannot compensate and the accuracy deteriorates. Therefore, if the drive current of the first light source (IA) is converted into a voltage by the first detection resistor (2B), and this voltage is outside the first predetermined range (compensable range),
The first window comparator (14) is energized to produce an output, energizing the OR circuit (20) and displaying the indicator (21).
to display an abnormality. At the same time, the first transistor (15) is connected to the first window comparator (14).
) is applied and conducts, and the output of the first relay coil (1
2) and energize the first. Second contact (12A), (12B
) from the solid line to the dotted line and connect. Therefore, the expected light from the healthy second light source (2B) can continue to enter the optical sensor (6) via the second optical fiber (3B), and the measured quantity can continue to be processed. It can be accurately determined in the circuit (18).

Next, on the first photoelectric converter (IOA) side, if the output of the average value circuit (16) is outside the second predetermined range (compensable range), the window comparator (1
7) is energized to produce an output, energizing the OR circuit % (20) and displaying an abnormality on the display (21). At the same time, the second transistor (19) is applied with the output of the second window comparator (17) and becomes conductive, exciting the second relay coil (13) and causing the third. Fourth contact (13A)? (13B) is connected by switching from the solid line state to the dotted line state. Therefore, the expected healthy second photoelectric converter (IOB) can be operated, and the measured quantity can be subsequently accurately determined in the processing circuit (18).

That is, 1st. Third detection resistor (2A) 1 (IIA)
The voltage appearing on the first photoelectric converter (IA) or the first photoelectric converter (IOA) becomes zero if the first photoelectric converter (IOA) is disconnected, and becomes abnormally high if there is a short circuit. Also, the first light source (IA) may deteriorate or the first light source (IA) may deteriorate. 3rd゜4th. Fifth optical fiber (3A
”), (5), (7).

Even if the propagation loss becomes abnormally large (9A) or the like, the output on the first photoelectric converter (IOA) side decreases. Therefore, the first. Second Wind Convergence Ri (14), (17)
In the first detection resistor (2 people), the average value circuit (16)
An abnormality can be detected by detecting that the output is outside the first to second predetermined ranges. Also, at the same time as this abnormality detection, the first. Second transistor (15).

(19) is made conductive, and the first. Second relay coil (12
), (13), the first . 2nd contact (12A), (12B), 3rd contact. Fourth contact (13
A), (13B) are switched from the solid line state to the dotted line state,
The second light source (IB), which is a healthy optical system that we are looking forward to,
A second photoelectric converter (IOB) can be coupled to the optical sensor (6).

In the above embodiment, temperature measurement was described, but other physical quantities such as temperature may also be measured.

As described above, according to the present invention, by constantly monitoring abnormalities in the optical system and switching to a healthy optical system when an abnormality occurs, it is possible to always provide reliable and accurate output according to the measured quantity. It has various effects such as being able to be obtained over a long period of time and being able to display an abnormality when an abnormality occurs.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of an optical measuring device according to the present invention. In the figure, (IA) and (IB) are the first. a second light source,
(2A) and (2B) are the first. Second sense resistor, (3A)
l (3B) is the first. The second optical fiber, (4) is @
1 optical coupler, (5) is the third optical fiber, (6) is the optical sensor, (7) is the fourth optical fiber, (8) is the second optical coupler, (9A), (9B ) is the fifth. The sixth optical fiber, (IOA), (IOB) is the 1.42nd photoelectric converter,
(IIA) and (IIB) are the third. Fourth detection resistor (12
), (13) are the first. Second relay coil, (12A
), (12B). (13A) and (13B) are the first. Second. 3rd゜Fourth contact, (14) is the first window comparator, (15)
is the first transistor, (16) is the average value circuit, (17
) is a second window comparator, (18) is a processing circuit, (19) is a second transistor, (20) is an OR circuit, and (21) is a display. Mr. Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 149605/1982 2
, Name of the invention Optical measuring device 3. Person making the amendment (1) 5. Detailed description of the invention in the specification subject to amendment 6. Contents of the amendment (1) In the Middle East page 4, line 20 of the specification: Correct "in the electric field" to "in the object to be measured." (2) In the first line of page 5, replace “voltage” with “acceleration”
I am corrected. (3) On page 6, line 10, the word "voltage" is corrected to "acceleration." (4) On page 7, line 6, the phrase "in an electric field" should be corrected to "in the object to be measured." (5) In the 6th line of page 7, replace ``voltage'' with ``acceleration.''
I am corrected. (6) On page 8, line 9 of the same page, replace “voltage” with “acceleration”
I am corrected. (7) On page 11, line 11, "temperature" is corrected to "acceleration." (8) In the 11th page, line 12 of the same text, "temperature, etc." is corrected to "temperature, voltage, etc." Above (2) 383-

Claims (1)

[Scope of Claims] 1. An optical sensor that modulates the intensity of light according to the amount to be measured, a plurality of light sources that are switched and coupled to the optical sensor and supply light to the optical sensor, and that are switched and coupled to the optical sensor. a plurality of photoelectric converters that receive the emitted light from the optical sensor and convert the emitted light into an electrical signal, and a processing circuit that extracts an electrical output corresponding to the measured quantity from the output of the photoelectric converter, By monitoring the driving current value of the light source and the average value of the electrical output of the photoelectric converter with respect to changes in the measured quantity, an abnormality in the optical system is detected, and when an abnormality is detected, the light source or the photoelectric converter in standby is detected. An optical measurement device characterized in that the optical sensor is switched and coupled to the optical sensor. 2. The plurality of light sources are each connected in series to a detection resistor, and a first comparator (1) determines whether or not a voltage drop across the detection resistor is within a first predetermined range. An optical measuring device according to claim 1. 3. A plurality of photoelectric converters are each connected in series with a detection resistor, and the electric voltage drop of the detection resistor is averaged by an average value circuit, and then the average value is calculated by a second window comparator. The optical measuring device according to claim 1 or 2, which determines whether or not the measured value is within a predetermined range. 4. A patent claim in which the processing circuit divides the alternating current component of the voltage drop of a detection resistor connected in series with a plurality of photoelectric converters by the average value of an average value circuit to obtain an output corresponding to the measured quantity. The optical measuring device according to any one of items 1 to 3. 5. 1st. Optical measuring device on the output of the second window comparator. (p) 6. The first relay coil is excited by the output of the first window comparator to switch the contacts of the first relay coil, so as to switch and couple the plurality of light sources to the optical sensor. An optical measuring device according to any one of claims 2 to 5. 7. The output of the second window comparator excites the second relay coil to switch the contacts of the second relay coil, and switch and couple the plurality of photoelectric converters to the optical sensor. An optical measuring device according to any one of claims 2 to 6.