JP2002310488A - Temperature detecting device and air conditioner using the same - Google Patents

Abstract

(57) [Problem] To narrow down the temperature detection range of a temperature detection device, to enable detection of the temperature of only a specific object, and to improve the temperature detection speed and temperature detection accuracy compared with the conventional one, and to provide an air conditioner and the like. To realize energy saving and comfortable air conditioning. SOLUTION: In a temperature detecting device 17, a heat transfer body 6 having a truncated cone-shaped concave portion for light guide whose opening area is larger than an area of an inner bottom surface 8 is mounted on the inner bottom surface 8 of the concave portion. A thermopile-type infrared sensor; and a lens which covers at least the opening of the heat transfer body and is fitted to the outer surface of the heat transfer body. 6 has a configuration in which the protrusion 9 is directly fitted to the printed circuit board 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature detecting device having a thermopile type infrared sensor and an air conditioner using the same to detect infrared radiation radiated from a floor or a wall of a room.

[0002]

2. Description of the Related Art All objects emit infrared rays proportional to the fourth power of the absolute temperature, and a general temperature detecting device detects the infrared rays. In general, infrared sensors used in temperature detection devices are broadly classified into quantum sensors and thermal sensors. Thermal sensors include thermopiles that use the thermoelectromotive effect, PZT that uses the pyroelectric effect, and thermistors that use the thermal conductivity effect. ing.

Conventionally, a thermistor-type infrared sensor has been used as a temperature detecting device which is mounted in an indoor part of an air conditioner and measures the surface temperature of a distant floor or wall surface.
This thermistor-type infrared sensor is a kind of temperature-sensitive resistance, and utilizes the property that the resistance changes in response to temperature changes. Temperature change was relatively detected.

[0004]

In such a thermistor type infrared sensor, no light guide or lens is used, and the temperature detection range, that is, the viewing angle of the sensor is not narrowed. However, there is a problem that the temperature of the surrounding wall is also detected when it is desired to detect the temperature. Also,
Since this sensor detects a relative temperature change by time measurement as described above, the detection speed is slow and the detection accuracy is not good.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a temperature detection device capable of narrowing the temperature detection range and detecting the temperature of only a specific object. Another object of the present invention is to provide a temperature detecting device that can improve the temperature detecting speed and the temperature detecting accuracy compared to the related art and can realize energy saving and comfortable air conditioning of an air conditioner and the like, and an air conditioner using the same. And

[0006]

In order to achieve the above object, in a temperature detecting apparatus according to the present invention, a thermopile type infrared sensor capable of detecting the temperature of a distant specific object with high accuracy is provided. Used as a means. The temperature detecting device is provided with a heat guide for a light guide that maintains a certain visual field, and a lens is provided at an opening of the heat conductor to further limit the visual field.

As described above, in the temperature detecting device using the infrared sensor according to the present invention, the temperature detecting device using the infrared sensor whose viewing angle is narrowed by the light guide is provided.
A light guide made of a heat transfer body having a cylindrical concave portion, and a thermopile infrared sensor mounted on the inner bottom surface of the concave portion are provided.

[0008] The light guide may be a heat transfer body having a truncated conical recess whose opening area is larger than the inner bottom area.

[0009] In the temperature detecting device, preferably,
At least an opening of the light guide is covered, and a lens fitted to the outer surface of the light guide is provided.

The light guide may be in contact with a printed circuit board, and a part of the light guide may be directly fitted to the printed circuit board.

Further, the thermopile type infrared sensor may be provided with a positioning means by fitting and sliding the infrared sensor in the recess.

The positioning means may be constituted by a groove or a protrusion formed in the recess and a protrusion or a groove formed in the thermopile type infrared sensor.

[0013] In the air conditioner according to the present invention, which detects infrared rays radiated from the floor surface or the wall surface of the room and calculates the surface temperature of the floor surface or the wall surface to control the temperature, It is configured to include any one of the temperature detecting devices as a detecting unit.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of an optical structure for detecting a surface temperature of a floor surface or a wall surface with high accuracy by a temperature detecting device of the present invention provided in an indoor part of an air conditioner will be described.
FIG. 1 shows an example of a detection range of a temperature detection device of the present invention provided in an air conditioner. When the height from the floor of the air conditioner 1 is about 2 m and the average of the surface temperatures of the floor area 2 of about 2 tatami mats is detected, the viewing angle θ of the temperature detecting device (not shown) is about 40. °.

Here, the viewing angle of a general thermopile type infrared sensor used in the temperature detecting device of the present invention is 10
Since the angle is 0 ° or more, a viewing angle is narrowed by providing a light guide tube or the like around the infrared sensor. FIG. 2 (a),
(B) and (c) are schematic views of side cross sections of the temperature detecting device of the present invention. Light guide tubes 4, 4 ', 4 "are provided around the thermopile type infrared sensor 3, and the viewing angle θ' is larger than the viewing angle θ". Normally, infrared rays radiated from the surface to be measured within the viewing angles θ ′, θ ″ are detected by the light receiving unit 5, and disturbance infrared rays from outside the viewing angles θ ′, θ ″ are output from the cylinders 4, 4 ′, 4 ″. The light is reflected by the inner surface and detected by the light receiving unit 5. At this time, the disturbance infrared incident angles A and B increase as the viewing angle increases, and the temperature measurement error increases accordingly. c) has the same viewing angle as that of FIG. 2A, but the cylinder 4 ″ has a narrower bottom so that the disturbance infrared incident angle C is smaller than the disturbance infrared incident angle A.

In order to reduce the temperature measurement error, it is sufficient to block the incidence of disturbance infrared rays, and an infrared transmitting lens (not shown) may be provided above the cylinders 4, 4 ', 4 ".

As described above, in a temperature detection device using a thermopile type infrared sensor, in order to accurately measure the temperature of the surface to be measured, only infrared light incident from the viewing angle of the temperature detection device is detected. Is a condition. In this case, infrared rays emitted from the light guide tube or lens also cause a measurement error. Therefore, it is desirable that the temperature of the tube or lens and the temperature of the infrared sensor are always the same.

Therefore, in the following embodiments of the present invention, a heat transfer member having a truncated conical light guide recess is used as an example of a light guide tube, and a lens is fitted to the heat transfer member. By doing so, the temperature error with the infrared sensor is reduced.

An embodiment in which the temperature detecting device of the present invention is used in an air conditioner will be described below with reference to the drawings.

FIG. 3 (a) shows a front view and a top view of an example of the heat transfer body of the present invention, and FIG. 3 (b) shows an A of FIG. 3 (a).
FIG. The heat transfer body 6 has a truncated cone-shaped light guide recess in which the area of the opening 7 is larger than the area of the inner bottom surface 8. A convex portion 9 for directly fitting to the printed circuit board is formed on the outer bottom surface of the heat transfer body 6, and a hole 1 for penetrating the electrode lead of the infrared sensor is formed on the inner bottom surface 8.
A groove 10 is formed in the concave portion of the heat transfer body 6 as a positioning means by fitting and sliding a convex portion of a thermopile type infrared sensor.

Here, by forming the concave portion of the heat transfer body 6 into a truncated conical shape as shown in FIG. 2C, the incident angle of disturbance infrared rays can be reduced with respect to a predetermined viewing angle.

The material of the heat transfer member 6 may be any material as long as it has high thermal conductivity and heat capacity and can be easily formed, and is preferably a metal, and more preferably aluminum. The large thermal conductivity allows the ambient temperature and the temperature of the infrared sensor to be the same, and the large thermal capacity makes it hard to be affected by sudden changes in the ambient temperature, enabling stable temperature detection. .

FIG. 4 is a perspective view of a thermopile type infrared sensor according to the present invention. Metal case 11 and metal case 1
A thermopile is provided inside the infrared transmission filter 12 provided on the upper surface of the device 1. Thermopile is
A plurality of thermocouples are connected in series on a silicon substrate, and one end of the thermocouple is a light receiving portion, and the other end is connected to a metal case 11 at a cold contact. With this configuration, the detection speed of the thermopile is higher than that of the thermistor, which is a temperature-sensitive resistor. When infrared light is incident on the light receiving portion, a voltage substantially proportional to the energy is generated at both ends of the thermocouple. Further, an electrode lead 14 is provided, and a convex portion 13 is provided on a side surface of the metal case 11 as positioning means by fitting and sliding in the groove 10 in FIG.

The means for positioning the heat transfer body 6 shown in FIG. 3 and the thermopile type infrared sensor 3 shown in FIG.
A ridge may be formed instead of 0, and a groove may be formed instead of the protrusion 13 of FIG.

FIG. 5 (a) shows a top view of an example of the temperature detecting device of the present invention, and FIG. 5 (b) shows the AA of FIG. 5 (a).
FIG. Here, the heat transfer body 6 shown in FIG. 3 was used, and the thermopile type infrared sensor 3 shown in FIG. 4 was used. The thermopile type infrared sensor 3 is positioned on the inner bottom surface 8 by fitting and sliding the protrusion 13 into the groove 10 of the heat transfer body 6, and the electrode lead 14 passes through the hole 15. Then, a lens 16 having the same inner surface shape as the outer surface shape of the heat transfer body 6 is fitted to the heat transfer body 6.
The temperature detecting device 17 is configured as described above.

In the temperature detecting device 17, for example, when the temperature of the heat transfer body 6 is higher than the temperature of the thermopile type infrared sensor 3 by 0.5 ° C., an error occurs that the temperature of the object to be measured is detected to be about 5 ° C. higher. . Therefore, in order to detect the temperature with high accuracy, the temperature difference between the infrared sensor 3 of the thermopile type, the heat transfer body 6 and the lens 16 should be as small as possible. That is, the thermopile-type infrared sensor 3 and the heat transfer body 6 are brought into contact with each other over a wide area, and the gap between the lens 16 and the heat transfer body 6 is eliminated, so that highly accurate temperature detection can be performed. In order to further improve the accuracy, the reflection of infrared rays on the inner surface of the concave portion of the heat transfer body 6 may be reduced, and it is preferable that the inner surface of the concave portion of the heat transfer member 6 be subjected to matte black processing.

The lens 16 is preferably a multi-lens Fresnel lens. This is because infrared rays are detected at the same number of points on the surface to be measured as the number of eyes and temperature measurement can be performed by averaging them. Further, the focus of the lens 16 must be accurately adjusted to the light receiving section of the thermopile type infrared sensor 3. The lens 16 is made of an inexpensive material having a high infrared transmittance and is preferably a silicon lens, and more preferably a polyethylene lens.

The outer shapes of the heat transfer body 6 and the lens 16 are not particularly limited, and may be any shapes that do not impair the aesthetic appearance when installed in an air conditioner.

Then, as means for installing the temperature detecting device 17 on the printed circuit board, the bottom surface of the heat transfer body 6 is in contact with the printed circuit board 18 and the projection 9 is directly fitted into a hole formed in the printed circuit board 18. I have. In addition, the electrode lead 14
Is fixed to the printed board 18 by solder 19 through the printed board 18, and the lens 16 is engaged with the printed board 18.

Next, a method of measuring a floor surface temperature in an air conditioner using the temperature detecting device of the present invention will be described. FIG. 6 shows a control circuit block diagram of an example of an air conditioner using the temperature detection device of the present invention. The offset voltage of an amplifier circuit composed of an operational amplifier circuit (not shown) is adjusted in advance by an offset adjustment circuit during production of the air conditioner. Further, since the output characteristics of the amplifier circuit change due to the change of the ambient temperature, an ambient temperature correction circuit is provided. When infrared light from the floor is received, a voltage is generated at both ends of the thermocouple of the infrared sensor, and the voltage is amplified about 5000 times by the amplifier circuit and input to an A / D port (not shown) of the microcomputer. Is done. The microcomputer measures an ambient temperature with an ambient temperature measuring thermistor provided near the infrared sensor, uses the measured temperature as the temperature of the infrared sensor itself, and calculates a floor surface temperature from an output value of the amplifier circuit. .

In general, since the amount of incident infrared energy and the electromotive voltage as the sensor output vary among individual infrared sensors, the sensitivity is adjusted during the production of the air conditioner.
The correction data for each infrared sensor is stored in the nonvolatile memory IC. Then, a value calculated by correcting based on the correction data when measuring the floor surface temperature is set as a floor surface temperature detection value.

The sensitivity of the infrared sensor is adjusted by:
A device that does not reflect infrared rays and maintains a stable absolute temperature, that is, a so-called black body can be used.

Next, a formula for calculating the floor surface temperature will be described. At the ambient temperature of the infrared sensor when measuring the floor temperature, the output voltage of the amplifier circuit when the infrared sensor input switch of the amplifier circuit is turned off is V
z, and the output voltage of the amplifier circuit when the infrared sensor input switch of the amplifier circuit is turned on is Vs.
If the ambient temperature of the infrared sensor is Ta and the temperature gradient of the output voltage of the amplifier circuit is A, (floor surface temperature) = Ta− (Vz−Vs) / A [° C.]. Here, the value of A uses the correction data stored in the nonvolatile memory.

In the above embodiments, the measurement of the floor surface temperature has been described, but the same applies to the measurement of the wall surface temperature.

[0035]

As described above, the temperature detecting device according to the present invention narrows the temperature detecting range and makes it possible to detect the temperature of only a specific object. In addition, the temperature detection device of the present invention can improve the temperature detection speed and the temperature detection accuracy as compared with the related art, and the air conditioner equipped with the temperature detection device of the present invention can realize energy saving and comfortable air conditioning. Becomes

[Brief description of the drawings]

FIG. 1 is an example of a detection range of a temperature detection device of the present invention attached to an air conditioner.

FIG. 2 is a schematic diagram of a side cross section of the temperature detection device of the present invention.

FIG. 3A is a front view and a top view of an example of a heat transfer body of the present invention. (B) It is sectional drawing on the AA line of FIG.3 (a).

FIG. 4 is a perspective view of a thermopile-type infrared sensor of the present invention.

FIG. 5A is a top view of an example of the temperature detecting device of the present invention. FIG. 5B is a sectional view taken along line AA of FIG.

FIG. 6 is a control circuit block diagram of an example of an air conditioner using the temperature detection device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air conditioner 3 Thermopile-type infrared sensor 6 Heat transfer body 7 Opening 8 Inner bottom surface 10 Groove 13 Convex part 16 Lens 17 Temperature detecting device 18 Printed circuit board

Claims (7)

[Claims] 1. A temperature detecting device using an infrared sensor whose viewing angle is narrowed by a light guide, comprising: a light guide made of a heat conductor having a cylindrical concave portion; and a thermopile type mounted on a bottom surface inside the concave portion. A temperature detection device comprising an infrared sensor. 2. The temperature detecting device according to claim 1, wherein the light guide is a heat transfer body having a truncated conical recess having an opening area larger than an inner bottom area. 3. The temperature detecting device according to claim 1, further comprising a lens that covers at least an opening of the light guide and is fitted to an outer surface of the light guide. 4. The temperature detecting device according to claim 1, wherein said light guide is in contact with a printed circuit board, and a part of said light guide is directly fitted to said printed circuit board. apparatus. 5. The temperature detecting device according to claim 1, further comprising positioning means for fitting and sliding said thermopile type infrared sensor inside said concave portion. 6. The temperature detecting device according to claim 5, wherein said positioning means comprises a groove or a protrusion formed in said concave portion, and a protrusion or a groove formed in said thermopile type infrared sensor. 7. An air conditioner that detects infrared rays radiated from a floor surface or a wall surface of a room and calculates and calculates a surface temperature of the floor surface or a wall surface, and controls the temperature. An air conditioner comprising the temperature detecting device according to any one of Items 1 to 6.