JPH06341903A - Temperature measuring method by infrared sensor - Google Patents

Abstract

PURPOSE:To provide a temperature measuring method by infrared sensor capable of highly precisely measuring temperature without having the influence of a thermal drift by the atmosphere or environment before measurement start. CONSTITUTION:In this temperature measuring method by an infrared sensor 6 in which a shutter 7 is provided in the regularly closed state on the front surface of the infrared sensor 6, and the temperature of a target is measured on the basis of the infrared ray inputted to the infrared sensor 6, the shutter 7 has a plurality of openings 7a, whereby, of a plurality of output signals from the infrared sensor 6 obtained by one reciprocation of the shutter 7, the first signal is eliminated, and arithmetic processing is carried out by use of the following signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a front surface of an infrared sensor with a shutter always closed, and when the shutter is opened, the temperature of an object is controlled based on infrared light input to the infrared sensor. The present invention relates to a temperature measuring method using an infrared sensor for measurement (hereinafter, simply referred to as a temperature measuring method).

[0002]

2. Description of the Related Art As a conventional temperature measuring method, for example, as disclosed in Japanese Patent Application Publication No. 503119 of 1987, a shutter is always closed in front of an infrared sensor provided in a body case of a thermometer. There is a device in which a single output signal is obtained from the infrared sensor when the power button is turned on and the shutter is opened and closed, the infrared light amount is measured from this output signal, and the temperature is displayed. .

[0003]

Although the above-mentioned conventional temperature measuring method is very easy to operate, it has the following disadvantages. That is, since the infrared light enters the infrared sensor immediately after the power is turned on, the peak of the signal output from the infrared sensor is unstable. Before the measurement is started, the sensitive part of the infrared sensor has the shutter closed, so that it is in an equilibrium state at the temperature inside the main body case. When infrared light suddenly enters such a sensitive section, it is affected by room temperature and the amount of infrared light, especially in a thermal infrared sensor, and is caused by the infrared light that enters immediately after the shutter is opened. This is because the first (first) signal is so unstable that it cannot be compared with the second and subsequent signals.

Therefore, in the conventional temperature measuring method,
For example, it is difficult to perform highly accurate temperature measurement such as ± 0.01 ° C to 0.1 ° C.

The present invention has been made in consideration of the above matters, and an object thereof is to perform highly accurate temperature measurement without being affected by thermal drift due to the atmosphere or environment before the start of measurement. It is to provide a temperature measuring method.

[0006]

In order to achieve the above object, the present invention provides an infrared sensor which is provided in front of an infrared sensor in a state where a shutter is always closed, and which is input to the infrared sensor when the shutter is opened. In a temperature measuring method using an infrared sensor for measuring the temperature of a target object based on light, a shutter having a plurality of apertures is used, and a single activation signal is given to this shutter, whereby the shutter is set to 1 Of the plurality of output signals from the infrared sensor obtained by performing the reciprocating operation once, the first signal is excluded, and the signal subsequent thereto is used for the arithmetic processing.

Further, a shutter having a single opening is used as the shutter, and only one start signal is given to this shutter, whereby a plurality of infrared sensors from the infrared sensor obtained by reciprocating the shutter a plurality of times are provided. It is also possible to exclude the first signal from the output signals of and to perform the arithmetic processing using the signal after that.

[0008]

For example, when a shutter having a plurality of apertures is used, the shutter is reciprocated once when only one start signal is given to the shutter, so that a plurality of signals are transmitted from the infrared sensor. Is output. In this case, as already explained, the first (first) signal due to the infrared light incident immediately after the opening of the shutter is so unstable that it cannot be compared with the second and subsequent signals. is there.

Therefore, in the present invention, in the arithmetic processing, not only the first signal is used, but the signals after the first signal are used, and a plurality of signals including the first signal are used. The effects of thermal drift due to the atmosphere and environment before the start of measurement are excluded. Further, since the operation for giving the activation signal only needs to be performed once, the operation required for the measurement is as simple as the conventional one. That is, the term “excluding the first signal and using the signal after that” in the present invention includes the above and.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an example of a temperature measuring device used in the temperature measuring method according to the present invention. First, in FIGS. 1 and 2, 1 is a main body case and 2 is a front surface of the main body case 1. It is a hollow portion opened to the side (upper side in the illustrated example). Reference numeral 3 denotes a condenser lens detachably provided on the front side so as to close the hollow portion 2. In the illustrated example, a holding member screwed to a screw portion 4 formed on a side wall surrounding the hollow portion 2. It is held at 5.

Reference numeral 6 denotes an infrared sensor provided on the rear side of the hollow portion 2, which is, for example, a dual type pyro sensor, and its two light receiving surfaces 6a and 6b face the lens 3 via a shutter 7 described later. ing. Reference numeral 8 is a thermistor for temperature compensation provided in the vicinity of the shutter 7 and the infrared sensor 6, and 9 is a cover body for protecting the outer surface of the lens 3.

It is preferable that the shutter 7 is always closed, and the movable portion thereof linearly reciprocates when a start signal is input. As such a shutter, the applicant of the present application has proposed that "Electromagnetic wave interrupting device" for which a patent application was filed on March 25 (Japanese Patent Application No. 4-193127
No.)

7 and 8 schematically show the configuration of the most basic double solenoid type electromagnetic wave interrupting device 10 of the electromagnetic wave interrupting devices according to the above patent application. In FIG. 7 and FIG. Is a self-holding solenoid, which comprises fixed iron cores 13 and 14, coils 15 and 16 wound in the same direction, movable iron cores 17 and 18, and permanent magnets 19 and 20, respectively. These self-holding solenoids 11 and 12 are arranged in a straight line with each other.

In this embodiment, for example, in the self-holding solenoid 11, the N pole is close to the movable iron core 17 so that the polarities of the magnetic poles of the permanent magnets 19 and 20 are opposite to each other. In No. 12, the S pole is arranged so as to be close to the movable iron core 18. Reference numeral 21 is a base frame for mounting and holding the self-holding solenoids 11 and 12 in a predetermined positional relationship.

22 is the self-holding solenoids 11 and 12
It is held by being connected to the movable iron cores 17 and 18 by a shielding portion provided between. The shield 22 is made of a material that shields electromagnetic waves such as light, such as plastic, iron, aluminum, stainless steel, and lead (effective for X-rays), and has an opening 24 in a part of the shield 23. . That is, the movable iron cores 17 and 18 and the shield portion 2
One movable body 25 is formed by 2. In addition,
Reference numeral 26 is a dual type pyrosensor including, for example, two light receiving elements 26a and 26b.

The electromagnetic wave interrupting device 1 configured as described above.
At 0, as shown in FIG.
1, 12 coils 15 and 16 are connected in parallel to each other,
When these certain DC pulse signals (one-shot signals) are applied to the coils 15 and 16, each self-holding solenoid 1
Magnetic fields in the same direction are generated in the first and the second magnetic fields.

Now, when the movable iron cores 17 and 18 are in the positions shown by the solid lines in the figure and the light is reaching the detector 26, the DC power supply 27 is connected as shown by the solid lines. Then, in the self-holding solenoid 11, a force that attracts the movable iron core 17 to the permanent magnet 19 side acts, and in the self-holding solenoid 12, a force that repels the movable iron core 18 from the permanent magnet 20 side acts. Then, the movable body 25 moves in the direction of the arrow indicated by the solid line, which moves the shielding portion 22 in the same direction, so that the detector 26 in the light receiving state is in the light shielding state. Then, in the self-holding solenoid 11, the movable iron core 17 is attracted to the permanent magnet 19 and holds that state.

On the other hand, when the movable iron cores 17 and 18 are at the positions shown by the phantom lines and the detector 26 is in the light-shielded state and the DC power supply 27 is connected as shown by the phantom lines, the self-holding solenoids 11 and 12 are shown. , The movable body 25 moves in the direction of the arrow indicated by the imaginary line, and the shield portion 22 moves in the same direction, so that the detector 26 in the light-shielded state receives light. It becomes a state. And
In the self-holding solenoid 12, the movable iron core 18 is attracted to the permanent magnet 20 and holds that state.

As described above, by inputting the control signals of the same polarity to the coils 15 and 16, the movable iron cores 17 and 1
Since the movable body 25 composed of 8 and the shielding portion 22 can be moved, the detector 26 can be switched from the light receiving state to the light shielding state or the opposite state. Then, if pulse-like control signals having different polarities are alternately applied to the coils 15 and 16, they can be used as a shutter or a chopper.

Therefore, in the temperature measuring device used in the method of the present invention, the electromagnetic wave interrupting device 10 which operates under the above-described operating principle is further developed and applied to the shutter as shown in FIGS. 1 and 3. Equipped with 7. That is,
In these figures, 7A is a shutter body, which corresponds to the movable body 25 in FIGS. 7 and 8. Also, 7
B and 7C are self-holding solenoids provided at both ends of the shutter body 7A. Then, a plurality of openings 7a are formed substantially in the center of the shutter body 7A.

FIG. 4 shows an infrared sensor 6, a shutter 7, a shutter driver 28 for driving the shutter 7, a circuit for processing the outputs of the infrared sensor 6 and the thermistor 8, a power supply circuit, etc. provided in the temperature measuring device. It is a figure which shows the relationship of.

In the temperature measuring device having the above structure, when the button is operated to turn on the power, the shutter driver 28
Outputs a single pulse signal as shown in FIGS. 3 and 5 (A), which is the self-holding solenoid 7B, 7C.
, The shutter body 7A linearly reciprocates once as shown in FIG. 3, and the infrared sensor 6 has four peaks P _{1 to} P ₄ as shown in FIG. 5B. The signal is output. Of this output signal, the first peak P
_The signal including ₁ is affected by the thermal drift due to the atmosphere or environment before the start of measurement and includes an error, so this is excluded, and calculation is performed based on the signal including the remaining peaks P _{2 to} P ₄ , For example, the temperature of the target object is obtained by the average value of the second peak signal P ₂ and the third peak signal P ₃ . The measurement result is displayed on the display unit 29 made of liquid crystal shown in FIG.

In the above embodiment, the first peak P ₁
Although the signal including is excluded and the calculation is performed based on the signal after that, the calculation may be performed based on, for example, the average value of a plurality of signals including the first signal.

When the output signal of the infrared sensor 6 is processed, if the magnitudes of a plurality of signals to be processed extend over two or more ranges, the data is discarded and the measurement is performed again. To do so. Further, the adjustment of the signal waveform such as the interval between the plurality of signals output from the infrared sensor 6 can be arbitrarily performed by appropriately setting the circuit constant.

The present invention is not limited to the above-described embodiment, and for example, as shown in FIG. 6, only one opening 7a is provided substantially at the center of the shutter body 7A, and the self-holding solenoid 7 is provided.
A plurality of pulse signals as shown in the figure may be given to B and 7C. In this case, a plurality of pulse signals are generated by the self-holding solenoid 7 by one button operation.
It is given to B and 7C.

The shutter 7 has a structure other than that described above, such as one using a microactuator or one using a movable piece type actuator, which linearly reciprocates to the infrared sensor 6. A device that interrupts the incidence of infrared light can be used.

[0028]

As described above, according to the present invention,
The temperature can be measured with high accuracy without being affected by the thermal drift due to the atmosphere or environment before starting the measurement.
For example, it becomes possible to perform highly accurate temperature measurement such as ± 0.01 ° C. to 0.1 ° C., and it can be widely applied to thermometers and general thermometers.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a temperature measuring device used in the method of the present invention.

FIG. 2 is a vertical sectional view of the temperature measuring device.

FIG. 3 is a diagram schematically showing a configuration of a shutter in the temperature measuring device.

FIG. 4 is a diagram schematically showing an overall configuration of the temperature measuring device.

FIG. 5 is an operation explanatory diagram of the present invention.

FIG. 6 is a diagram schematically showing a configuration of a shutter according to another embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of an electromagnetic wave interrupting device which is a basis of the temperature measuring device.

FIG. 8 is a sectional view schematically showing a main part of the electromagnetic wave interrupting device.

[Explanation of symbols]

 6 ... Infrared sensor, 7 ... Shutter, 7a ... Opening.

Claims (2)

[Claims] 1. An infrared sensor for measuring the temperature of a target object based on infrared light input to the infrared sensor when the shutter is opened in front of the infrared sensor with the shutter always closed. In the temperature measuring method, a shutter having a plurality of apertures is used, and a single activation signal is given to the shutter, whereby a plurality of infrared sensors from an infrared sensor obtained by one reciprocating operation of the shutter are provided. A temperature measuring method using an infrared sensor, wherein the first signal is excluded from the output signals and the subsequent signals are used for the arithmetic processing. 2. An infrared sensor for measuring a temperature of a target object based on infrared light input to the infrared sensor when the shutter is opened, the shutter being provided on the front surface of the infrared sensor with the shutter always closed. In the temperature measuring method, a shutter having a single opening is used, and a single activation signal is given to this shutter, whereby a plurality of infrared sensors from the infrared sensor obtained by reciprocating the shutter multiple times are provided. The first signal of the output signals of
A temperature measuring method using an infrared sensor, characterized in that arithmetic processing is performed using signals after that.