JP2010249626A - Temperature distribution detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature distribution detector for detecting temperature distribution at high speed by minimizing the moving range of an infrared detecting element group. <P>SOLUTION: This temperature distribution detector includes a plurality of rectilinear infrared detecting element groups. The respective element groups are disposed so as to equalize intervals between visual fields. A drive control means causes a drive means to move the element groups in a direction orthogonal to the element groups. The range of the move is only an interval between neighboring rectilinear infrared detecting element groups since reciprocation is made by an angle corresponding to a visual field interval of the element groups as to intervals between the moves. Minimizing the range of the move makes it possible to detect temperature distribution at high speed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a temperature distribution detection device for detecting a temperature distribution within a predetermined range such as a heating space for heating food or a living space in a home.

  In microwave ovens that cook food in a heating cabinet and air conditioners that heat living spaces, various temperatures that detect temperature distributions are used for appropriate heating control by detecting the temperature distribution in the heating range. A distribution detection device has been proposed.

  With reference to FIG. 7, an example in which a temperature distribution is detected with a configuration in which an infrared detection element group arranged two-dimensionally along a linear axis is rotationally driven in a direction perpendicular to the linear axis will be described (see Patent Document 1). In FIG. 7, the thermopile heat detection elements 1 a to 1 i are two-dimensionally arranged along the linear axis 2 to constitute a thermopile heat detection element group.

  By using a stepping motor in this configuration and driving a two-dimensional thermopile heat detection element group in a direction orthogonal to the linear axis 2, the detection area is moved to A, B, C, D, E, A to A temperature distribution can be detected in a wide range of E. The temperature distribution detection can be repeated in time series by repeatedly reciprocating this range.

JP 2006-177848 A

  However, in order to detect the temperature distribution by moving the two-dimensional thermopile heat detection element group having such a configuration, it is necessary to move a wide range. That is, it must be moved from the linear axis A to the linear axis E in FIG. Therefore, there is a problem that it takes a long time to detect the temperature distribution due to the movement time.

  For example, when food in a heating chamber is heated in a microwave oven or the like, the food is rapidly rising in temperature, and in order to accurately detect and control the changing food temperature It is necessary to detect the temperature distribution faster.

  In addition, in order to correctly detect the temperature distribution of a person's living space with an air conditioner, it is necessary to detect the temperature distribution at a speed higher than the moving speed of the person. In any case, it is necessary to detect the temperature distribution faster, and for this purpose, the moving range of the infrared detection element group must be as small as possible.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a temperature distribution detection device that detects the temperature distribution at high speed by minimizing the movement range of the infrared detection element group.

The temperature distribution detection apparatus of the present invention has a plurality of linear infrared detection element groups in which a plurality of infrared detection elements for detecting infrared rays are linearly arranged, and the plurality of linear infrared detection element groups have a predetermined field of view, etc. A two-dimensional infrared detection element group configured to be spaced apart, a signal processing circuit that selects, amplifies and processes a detection signal from each infrared detection element of the two-dimensional infrared detection element group, and the linear shape Drive means for moving the two-dimensional infrared detection element group in a direction orthogonal to the linear direction of the infrared detection element group, and drive control means for controlling the drive means, wherein the drive control means is the plurality of linear infrared rays The drive means reciprocates the angle of the visual field interval of the detection element group.

  With this configuration, an output corresponding to the temperature at a position where each infrared detection element arranged in a straight line becomes a visual field is generated, and the signal processing circuit sequentially selects and amplifies each infrared detection element for signal processing. And there are a plurality of linear infrared detection element groups, and the visual field intervals of each linear infrared detection element group are equally arranged, and the drive control means has a plurality of directions in a direction perpendicular to the linear infrared detection element group by the drive means. The linear infrared detection element group is moved, and the movement interval is reciprocated only by the angle of the visual field interval of each linear infrared detection element group, so the movement range is only the interval between adjacent linear infrared detection element groups. Thus, it is possible to detect the temperature distribution at high speed while minimizing the moving range.

  In the temperature distribution detection apparatus of the present invention, the signal processing circuit includes an AD converter that digitizes a signal, a temperature conversion unit that converts temperature information based on an AD conversion result of the AD converter, and the temperature Since it has a configuration including a communication control unit that outputs the temperature information converted by the conversion unit by serial communication, the AD converter AD converts the amplified output signal of each infrared detection element, and the temperature conversion unit converts the temperature Since it is converted into information and the communication control unit outputs temperature information through serial communication, it is possible to detect an appropriate temperature distribution that is resistant to noise and the like.

  In the temperature distribution detection apparatus of the present invention, the drive control means controls to move with an overlapping range so as to coincide with the field of view of the adjacent linear infrared detection element group at the end of the reciprocating drive. The signal processing circuit is configured to correct the temperature conversion of the temperature conversion unit based on the output of the position where the field of view of the adjacent linear infrared detection element groups adjacent to each other at the end of the reciprocating drive matches. By detecting the temperature of the same field of view with the detection elements, they can be corrected for each other, so that variations between elements can be absorbed and the accuracy of temperature distribution detection can be improved.

  According to the present invention, there are a plurality of linear infrared detection element groups, each linear infrared detection element group is arranged so that the visual field intervals are equal, and the drive control means is driven by the linear infrared detection element by the drive means. A plurality of linear infrared detection element groups are moved in a direction perpendicular to the group, and the movement interval is reciprocated only by the angle of the visual field interval of each linear infrared detection element group, so the movement range is an adjacent linear shape It is only the distance from the infrared detection element group, and it becomes possible to detect the temperature distribution at high speed while minimizing the moving range.

Side surface cross-section block diagram of the temperature distribution detection apparatus concerning Embodiment 1 of this invention 1 is a configuration diagram of a two-dimensional infrared detection element group of a temperature distribution detection device according to a first embodiment of the present invention. Explanatory drawing of the two-dimensional temperature distribution result by the temperature distribution detection apparatus concerning Embodiment 1 of this invention. 1 is a configuration diagram of a signal processing circuit of a temperature distribution detection device according to a first exemplary embodiment of the present invention. Explanatory drawing of the two-dimensional temperature distribution result by the temperature distribution detection apparatus concerning Embodiment 2 of this invention. The block diagram of the signal processing circuit of the temperature distribution detection apparatus concerning Embodiment 2 of this invention Explanatory drawing of the two-dimensional temperature distribution result by the conventional temperature distribution detector

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of a temperature distribution detection apparatus of the present invention. Each infrared detection element in the two-dimensional infrared detection element group 1 is composed of a thermopile and is enclosed in a metal can 3. A lens 4 is attached to the can 3, and the field of view of each infrared detection element is defined by the positional relationship between the focal point of the lens 4 and the two-dimensional infrared detection element 1.

  An output signal of each infrared detection element of the two-dimensional infrared detection element group 1 is connected to the printed circuit board 6 through the metal wire 5 and fixed together with the can 2. The printed circuit board 6 is supplied with power and is equipped with a signal processing circuit 7 composed of various electronic components. A connector 8 is mounted on the printed circuit board 7, and a lead wire 9 is connected to the connector 8, and a signal processed by the signal processing circuit 7 is output.

  The above is housed in a case 10 made of resin, and the case 10 is provided with a passage hole 11 through which infrared rays pass and a lead wire hole 12 through which the lead wire 9 passes. Further, a stepping motor 13 as a driving means is attached to a case 8 in which the two-dimensional infrared detection element group 1 is housed, and drives the entire case 8 and reciprocates in the direction toward the back and front of the drawing. Is. The drive control means 14 controls the driving of the stepping motor 13.

  FIG. 2 shows the configuration of the two-dimensional infrared detection element group 1. The two-dimensional infrared detection element group 1 includes a linear infrared detection element group 1A composed of thermopiles 1a, 1d, and 1g, a linear infrared detection element group 1B composed of thermopiles 1b, 1e, and 1h, and thermopiles 1c, 1f, and 1i. The linear infrared detection element group 1C is configured so that the visual field interval between the linear infrared detection element groups 1A and 1B is equal to the visual field interval between the linear infrared detection element groups 1B and 1C. .

  A linear axis 2 of the linear infrared detecting element group 1B arranged in the center is provided, and the visual field is reciprocated by the stepping motor 13 and the drive control means 14 in the left and right directions of the drawing so as to be orthogonal to the linear axis 2. It is something that moves.

  In FIG. 2, the linear detection element groups 1A, 1B, and 1C are moved by the stepping motor 13 and the drive control means 14, and the temperature distribution is acquired so as to fill the gaps. Detect temperature distribution. That is, the linear axis 2 is moved to 2-1, 2-2, 2-3, 2-4, 2-5.

  Then, the linear detection element group 1A composed of the thermopiles 1a, 1d, and 1g detects the temperature distribution in the region A in FIG. 3, and the linear detection element group 1B composed of the thermopile 1b, 1e, and 1h The linear detection element group 1C composed of the thermopiles 1c, 1f, and 1i detects the temperature distribution in the region B, and detects the temperature distribution in the region C, and as a whole, is sufficiently wider than the movement of the linear axis 2. The temperature distribution in the region can be detected.

  As a result, since the rotation angle by the stepping motor can be made sufficiently small and the temperature distribution of the same width can be detected as compared with the conventional case, the temperature distribution can be detected at high speed.

  Next, the configuration of the signal processing circuit 7 will be described with reference to FIG. The switchers 15A, 15B, and 15C are generally called multiplexers, and select one of the infrared detectors based on the signal from the switch signal generator 16 to switch the connection to the signal processing circuit at the subsequent stage.

  The switch 15A switches the thermopiles 1a, 1d, and 1g belonging to the linear infrared detection element group 1A, and the switch 15B switches the thermopiles 1b, 1e, and 1h that belong to the linear infrared detection element group 1B. 15C performs switching of the thermopiles 1c, 1f, and 1i belonging to the linear infrared detection element group 1B.

  The amplifier circuits 17A, 17B, and 17C amplify the signal of each thermopile connected by the switchers 15A, 16A, and 17A. The AD converters 18A, 18B, and 18C convert the amplified analog signals of the thermopiles into digital values.

  The switchers 15A to 15C, the amplifier circuits 17A to 17C, and the AD converters 18A to 18C all correspond to the linear infrared detection element groups 1A, 1B, and 1C, and the thermopiles 1a, 1b, and 1c are simultaneously used. It is selected, amplified and A / D converted, and the thermopiles 1d, 1e and 1f are simultaneously selected and the thermopiles 1d, 1h and 1i are simultaneously selected, amplified and A / D converted.

  The temperature conversion unit 19 sequentially calculates temperature values based on the thermopile signals converted into digital values by the AD converters 18A to 18C. Since the thermopiles 1a to 1i vary in sensitivity, the sensitivity is measured in advance in order to accurately convert the temperature, and a constant corresponding to the sensitivity is stored in the sensitivity storage unit 20.

  In the temperature conversion part 19, the temperature of the location which becomes the visual field of the thermopile 1a-1i is accurately calculated by converting temperature according to the sensitivity constant memorize | stored in this sensitivity memory | storage part 20. FIG.

  In general, the thermopile outputs a voltage proportional to the difference between the fourth power of the temperature of the object to be viewed and the fourth power of the temperature of the thermopile itself.

  Therefore, the temperature T0 of the thermopile itself is measured by a contact-type temperature sensor (not shown) such as a thermistor, the fourth power of the temperature T0 is calculated, and converted into a digital value by the AD converters 18A to 18C. When the voltage value of each infrared detection element multiplied by a constant K is added and the fourth root of the added value is calculated, the temperature of the object to be viewed is obtained.

  What corresponds to this constant K is proportional to the reciprocal of the sensitivity of the thermopile, and each thermopile has a variation in sensitivity. Therefore, instead of a constant K, a constant Ka corresponding to each thermopile 1a to 1i. ˜Ki are stored in the sensitivity constant storage unit 20.

  The communication control unit 21 includes a transmitter 22 and a receiver 23, and serially transmits from the transmitter 22 the temperatures at the locations that are the fields of view of the thermopiles 1 a to 1 i calculated by the temperature conversion unit 19. To go.

  The transmission destination controls the temperature based on the temperature distribution detected by the infrared sensor, such as a controller that controls the heating and cooling of an air conditioner and a controller that controls the heating of the microwave oven. The receiver 23 also receives a signal from the transmission destination in order to take communication timing.

  In this way, since the digital value is serially communicated instead of transmitting the lead wire 9 with the analog voltage, it is possible to detect the temperature distribution with high accuracy that is not easily affected by noise or the like.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. Since the basic configuration shown in FIGS. 1 and 2 described in the first embodiment is not changed, description thereof is omitted.

  In FIG. 2, the linear detection element groups 1A, 1B, and 1C are moved by the stepping motor 13 and the drive control means 14, and the temperature distribution is acquired so as to fill the gaps. As shown in FIG. Detect distribution.

  At this time, the number of steps to be moved is increased by one from the first embodiment so that the right end of area A and the left end of area B overlap, and the right end of area B and the left end of area C overlap. I have to. That is, at the places where the ends of the regions A and B overlap, the thermopile 1a and the thermopile 1b, the thermopile 1d and the thermopile 1e, and the thermopile 1g and the thermopile 1h respectively detect the temperature of the same visual field.

  Similarly, in the places where the ends of the regions B and C overlap, the thermopile 1b and the thermopile 1c, the thermopile 1e and the thermopile 1f, and the thermopile 1h and the thermopile 1i respectively detect the temperature of the same visual field.

  If the temperature of the same visual field is detected at the same time, the same temperature should be detected. This is not simultaneous because the field of view is actually moved by the stepping motor, but if it is sufficiently short, it can be handled as detecting the same temperature.

  FIG. 6 shows the configuration of the signal processing circuit 7. The difference from the first embodiment is that the temperature conversion unit 19 includes a correction unit 24. The correction unit 24 corrects the sensitivity constants Ka to Kc of the thermopiles 1a to 1i.

  For the sensitivity constants Ka, Kb, and Kc of the thermopiles 1a, 1b, and 1c, the detection temperature by 1a in the region where A and B overlap is equal to the detection temperature by 1b, and the region where B and C overlap The sensitivity constants Ka, Kb, and Kc are recalculated and corrected so that the detected temperature by 1b and the detected temperature by 1c are equal.

  There are various correction methods, but an example will be described. First, the thermopile 1a and the thermopile 1c are compared, and the one having the larger temperature difference from the temperature of the thermopile itself is selected and corrected. If it is the thermopile 1a, the temperatures of the thermopile 1a and the thermopile 1b at the point where the regions A and B overlap are equal to each other and have an average value.

  Then, assuming that the correct temperature is the average value of the two values, the sensitivity constant Ka is again calculated from the difference between the fourth power of the average temperature and the fourth power of the temperature of the thermopile itself, and the outputs of the thermopiles 1a and 1b obtained by AD conversion. , Kb is calculated. Then, the sensitivity constants Ka and Kb stored in the sensitivity storage unit 20 are rewritten.

  Next, the temperature of the visual field by the thermopile 1b calculated based on the rewritten Kb and the temperature of the visual field by the thermopile 1c at the point where the regions B and C overlap are equal to each other, and the calculation was performed by the sensitivity-corrected Kb. The sensitivity constant Kc is calculated again from the difference between the fourth power of the temperature of the thermopile 1b and the fourth power of the temperature of the thermopile itself, and the output of the thermopile 1c obtained by AD conversion. Then, the sensitivity constant Kc stored in the sensitivity storage unit 20 is rewritten.

Similarly, Ke, Kf, and Ki are rewritten from the temperatures of the thermopiles 1d, 1e, and 1f at the overlapping regions, and Kg, Kh, and Ki are calculated from the temperatures of the thermopiles 1g, 1h, and 1i at the overlapping regions. rewrite. The next temperature distribution detection is performed with the sensitivity constants Ka to Ki thus rewritten.

  Sensitivity is measured in advance and stored in the temperature storage unit 20 as a sensitivity constant. However, in actual environments, the value is often slightly deviated depending on temperature, humidity, emissivity of an object, and the like. When detecting temperature distribution with a plurality of thermopiles, there is a difference in sensitivity depending on the thermopile. Therefore, the distribution of discontinuities at the boundary between the region A and the region B and between the region B and the region C is different. However, it is possible to detect the temperature distribution with higher accuracy by correcting the fact that the temperature at such a boundary is the same temperature.

  In the above description, the thermopile is used as the infrared detection element. However, this may be replaced with another, for example, when the field of view is an object using a pyroelectric sensor and a chopper, and when it is blocked by the chopper. The output difference may be the output.

  In addition, a linear infrared detection element group is configured with three elements, or a two-dimensional infrared detection element group is formed by using three rows, but this is not limited to the configuration, and the linear infrared detection element group is used. If the number of infrared detection elements constituting the is increased, a finer temperature distribution can be detected, and if the number of columns is increased, the temperature distribution can be detected at a higher speed.

  As described above, in the temperature distribution detection device according to the present invention, the movement range of the infrared detection element group is only the interval between the adjacent linear infrared detection element groups, and the temperature distribution can be obtained at high speed with the movement range being minimized. Since it can be detected, it can be applied to uses such as temperature distribution detection of a heating space in a microwave oven or the like, or temperature distribution detection of a human living space in an air conditioner or the like.

DESCRIPTION OF SYMBOLS 1 Two-dimensional infrared detection element group 1a-1i Thermopile 1A-1C Linear infrared detection element group 7 Signal processing circuit 13 Drive means 14 Drive control means 18A-18C AD converter 19 Temperature conversion part 21 Communication control part 24 Correction | amendment part

Claims (3)

A configuration having a plurality of linear infrared detection element groups in which a plurality of infrared detection elements for detecting infrared rays are linearly arranged, and the plurality of linear infrared detection element groups are arranged so that the visual field is at a predetermined equal interval. A two-dimensional infrared detection element group, a signal processing circuit that selects, amplifies and processes a detection signal from each infrared detection element of the two-dimensional infrared detection element group, and a direction orthogonal to the linear direction of the linear infrared detection element group Driving means for moving the two-dimensional infrared detection element group in a direction to move, and drive control means for controlling the drive means, wherein the drive control means is an angle of the field of view of the plurality of linear infrared detection element groups A temperature distribution detecting device that reciprocates only by the driving means. The signal processing circuit includes an AD converter that digitizes a signal, a temperature conversion unit that converts temperature information based on an AD conversion result of the AD converter, and temperature information converted by the temperature conversion unit through serial communication. The temperature distribution detection device according to claim 1, further comprising a communication control unit that outputs the temperature distribution. The drive control means controls to move with an overlapping range so as to coincide with the field of view of the adjacent linear infrared detection element group at the end of the reciprocating drive, and the signal processing circuit controls the end of the reciprocating drive. The temperature distribution detection apparatus according to claim 2, further comprising: a correction unit that corrects temperature conversion of the temperature conversion unit based on an output at a position where the fields of adjacent linear infrared detection element groups in the unit match.

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