JPS6116011B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical measurement device such as a radiation thermometer that uses electromagnetic waves as a measurement medium or measurement target.

In addition to radiation thermometers, this type of optical measurement device that uses electromagnetic waves as a measurement medium or measurement object includes illumination meters, luminance meters, transmittance meters, etc., and their detection elements are generally thermoplates, thermistors, and bolometers. Thermocouple type detection element such as Si, PbS,
A photoelectric detection element such as PbSe is used. Since these detection elements have nonlinear characteristics, the range of characteristics that are convenient for measurement is limited, and therefore, in order to be a highly accurate measuring device, it must be a measuring device that measures within a narrow range. I didn't get it.

In view of the above points, the present invention has been developed by inserting two or more neutral density filters having mutually different transmittances or colored filters having mutually different transmission wavelengths into the transmitting window of a rotary disk that functions as a chopper. However, by selecting the detection element output from the electromagnetic waves irradiated to the detection element through an arbitrary filter among each filter and outputting the energy amount of the electromagnetic waves as an output signal, it is possible to spread over a wide range. The object of the present invention is to provide an optical measuring device that can perform highly accurate measurements.

Next, a first example in which the device according to the present invention is applied to a radiation thermometer will be described.

FIG. 1 is an explanatory view of the mechanism of a radiation thermometer. An objective lens 2 is provided on the front side of the radiation thermometer 1, and a rotary disk 3 is provided behind the objective lens 2. The rotary disk 3 has its center connected to the rotating shaft 4a of the motor 4 and is rotated at a constant speed, and furthermore, a plurality of transparent windows 5 are formed at positions equidistant from the rotation center. In this embodiment, the transmission windows 5 include four transmission windows 5a,
5b, 5c, and 5d are formed, and each transmission window 5a, 5b, 5c, and 5d is provided with a neutral density filter 6a, 6b, 6c, and 6d having different transmittances.
is inserted. Furthermore, a detection element 8 is provided behind the rotary disk 3, and the detection element 8 is positioned on a straight line connecting the objective lens 2 and one of the transmission windows 5. The detection element 8 is a thermoelectric detection element such as a thermopile, a thermistor/porometer, or a photoelectric detection element such as Si, PbS, PbSe, etc., and the output of the detection element 8 is input to an amplifier 9. .

Further, a synchronizing signal generator 7 is provided close to the outer periphery of the rotating disk 3, and this synchronizing signal generator 7 has a number corresponding to the number of transmitting windows 5, that is, four synchronizing signal generators in this embodiment. Vessels 7a, 7b, 7
A proximity switch, a phototube, etc. are used as synchronizing signal generators. These synchronizing signal generators 7a, 7b, 7c, and 7d correspond to the transmission windows 5a, 5b, 5c, and 5d, respectively, when the transmission window 5 is located on a straight line connecting the objective lens 2 and the detection element 8. are configured such that synchronizing signals _P1 to _P4 are outputted from corresponding synchronizing signal generators 7a to 7d, respectively. The synchronization signal generator 7 is connected to a signal separation circuit 11 via a changeover switch 10, and the synchronization signal P is input to the circuit 11, and the signal separation circuit 11 receives the output signal e from the amplifier 9. It has been entered.

Furthermore, this signal separation circuit 11 is connected to a rectifier circuit 12, and when the synchronizing signal P is applied, it becomes conductive and applies an output signal e to the rectifier circuit 12, that is, it is a switching circuit. The rectifier circuit 12 is configured to convert the signal converted from DC to AC by the rotating disk 3 into a DC signal again, and the thermometer output a outputted by the rectifier circuit 12 is supplied to a recording instrument, automatic control, etc. ing.

The operation of the radiation thermometer 1 with the above configuration will be explained below.

The radiation energy from the object to be measured is transmitted to the objective lens 2.
When the rotary disk 3 is irradiated with the radiant energy, since the rotary disk 3 is always in a rotating state, this radiant energy passes through the transmission window 5 intermittently and is intermittently irradiated onto the detection element 8. That is, the rotary disk 3 has a function as a chopper and performs DC-AC conversion, and at the same time, dark filters 6a to 6d having different transmittances are inserted into the transmission windows 5a to 5d, respectively. Therefore, the detection element 8 is irradiated with radiant energy that is attenuated one after another.
As the output signal e outputted from the detection element 8 via the amplifier 9, the output signal e ₁ is as shown in FIG.
to e ₄ will appear repeatedly. This output signal e is selected in the signal separation circuit 11 by the synchronization signal P from the synchronization signal generator 7, and the desired output signals e1 _{to e4} are converted into a DC signal again in the rectification circuit 12, and the thermometer is It is output as output a. More specifically, the synchronization signal P is transmitted to the synchronization signal generators 7a to 7d and the corresponding transmission windows 5.
It is generated when windows a to 5d are located on a straight line connecting the objective lens 2 and the detection element 8. For example, the transmission window 5a having the largest transmittance is located on the straight line connecting the objective lens 2 and the detection element 8. When this occurs, the synchronization signal generator 7a generates the synchronization signal _P1 . At this time, if the changeover switch 10 selects the synchronization signal generator 7a, the synchronization signal is sent to the signal separation circuit 11.
P ₁ is applied, and this synchronizing signal P ₁ is applied to changeover switch 1.
This will be repeated until you switch 0 to something else. This synchronization signal _P1 is an output signal due to the radiant energy that has passed through the transmission window 5a in the output signal e from the detection element 8.
Since the time is made to coincide with e ₁ , the DC signal a ₁ obtained by rectifying the output signal e ₁ is output as the thermometer output a outputted via the rectifier circuit 12 .

Also, the changeover switch 10 is connected to another synchronous signal generator 7.
When the switches are switched to b to 7d, one of the corresponding output signals e ₂ to e ₄ is similarly output as the thermometer output a. The thermometer outputs a ₁ to a ₄ outputted in this way have appropriate characteristics in each temperature range as shown in FIG. can be known. This display device 16 has scales 17a, 17b, 17c, and 17d corresponding to the thermometer outputs _a1 to _a4 , and each scale 17 is set in accordance with the nonlinear characteristics of the thermometer outputs _a1 to _a4 . carved at uneven intervals.

Next, second to fourth embodiments in which the device according to the present invention is applied to a radiation thermometer will be described with reference to FIGS. 5 to 7.

Note that the same reference numerals are given to the same parts as in the first embodiment described above, and the explanation thereof will be omitted.

FIG. 5 shows a second embodiment in which only one synchronization generator 7 is used and a pulse shift circuit 13 is used. The synchronizing signal P is detected by the pulse shift circuit 13.
has been entered. This pulse shift circuit 13 has the same number of output terminals 13a to 13d as the transmission windows 5, and is configured to repeatedly apply the synchronizing signal P to the output terminals 13a to 13d in order.

Therefore, the signal separation circuit 11 is selected depending on the output terminals 13a to 13d selected by the changeover switch 10.
One of the output signals e ₁ to e ₄ is selected.

Figure 6 shows the same number of signal separation circuits 1 as the number of transmission windows 5.
1 is used, and the synchronization signals P ₁ to P ₄ from the synchronization signal generators 7 a to 7 d are sent to dedicated signal separation circuits 11 a, respectively.
The output signal e from the amplifier 9 is input to all the signal separation circuits 11a to 11d.
It has been added to 1d. Further, each of the signal separation circuits 11a to 11d is connected to a rectifier circuit 12 via a changeover switch 10.

FIG. 7 shows a fourth embodiment in which an automatic range switching device is added to the radiation thermometer according to the first embodiment, and a comparator 14 is used as the automatic range switching device. This comparator 14 receives the output values from the reference setter 15 and the rectifier 12 as input, and is configured to output when the output value from the rectifier 12 exceeds a predetermined upper limit value and falls below a predetermined lower limit value. , the selector switch 10 is sequentially switched by the output of the comparator 14, and the appropriate output signal e is automatically selected.

Incidentally, although a neutral density filter is used in each of the above-mentioned embodiments, a configuration may also be adopted in which colored filters having mutually different transmission wavelengths are used.

As explained above, according to the present invention, two or more neutral density filters having mutually different transmittances or colored filters having mutually different transmittance wavelengths are inserted into the transmitting window of the rotary disk which functions as a chopper. ,
The configuration is such that the detection element output from the electromagnetic waves irradiated to the detection element through an arbitrary filter is selected from each filter, and the energy amount of the electromagnetic waves is output as an output signal, so accuracy can be improved over a wide range. This has the effect of providing an optical measuring device that can perform high-quality measurements.

[Brief explanation of the drawing]

FIG. 1 is a mechanism explanatory diagram showing a first embodiment in which the device according to the present invention is applied to a radiation thermometer, FIG. 2 is a graph diagram showing the relationship between the output signal e and the synchronization signal P, and FIG. The figure is a graph showing the relationship between thermometer output and temperature, Figure 4 is a front view of the display device, and Figures 5, 6, and
FIG. 7 is a mechanism explanatory diagram showing the second, third, and fourth embodiments. 3...Rotary disk, 5...Transmission window, 6...Filter, 7...
Synchronous signal generator, 8...detection element, 11...signal separation circuit.

Claims (1)

[Claims] 1. At least a detection element for detecting electromagnetic waves as a measurement medium or measurement target, a rotary disk having two or more transmission windows provided in the middle of the propagation path of the electromagnetic waves to the detection element, and a rotary disk that is inserted into the transmission windows. the filter, a synchronization signal generation device for detecting the position of the transmission window, and a signal separation circuit for selectively separating the detection signal from the detection element using the synchronization signal of the synchronization signal generation device; The filters are neutral density filters with mutually different transmittances or colored filters with mutually different transmission wavelengths, and the detection element output is selected based on the electromagnetic waves irradiated to the detection element through any one of the above filters. An optical measuring device characterized in that it is configured to output the energy amount of the electromagnetic waves as an output signal.