JPH10185616A - Sensor correcting device corresponding to unevenness of initial time - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically correct the sensor characteristic per each product, and to realize a desirable operating condition even in the case where a sensor having unevenness is used by providing a memory means for storing the ideal characteristic of an active element and a detecting means for detecting the real condition. SOLUTION: A microcomputer 40 inside of an air cleaner is provided with an active element real measurement value detecting means 42 and an ideal characteristic memory device 48 for storing the ideal characteristic of an active element, which forms a dust sensor 10, and a b0-b1 memory device 60 such as a nonvolatile memory, which holds a difference between a detection value (b1) of the detecting means 42 and a value (b0) held by the memory device 48, is connected to the microcomputer 40. At the first time of electrifying of an equipment, a real measurement value of the detecting means 42 when dust is eliminated by the operation of a dust collecting unit 50 is processed by the predetermined method, and a result thereof is stored in the memory device 60. In the case of normal operation, a value of the b0-b1 memory device 60 is added to the real measurement value, which is obtained by the detecting means 42, so as to decide a value to be output to the dust collecting unit 50 for control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric and electronic device for monitoring an operation state using various sensors, and more particularly to a sensor correction device for correcting a variation in initial characteristics of a sensing element.

[0002]

2. Description of the Related Art Conventionally, in an electric or electronic device, various kinds of sensors are used to detect the operating environment of the device and to control the operating state, and to control the device based on the output result of the sensor. Many have been proposed. The sensor is formed of, for example, an active element including a transmitting (light emitting) unit and a passive element including a receiving (light receiving) unit that receives information of the active element.

[0003] As an example of the above, for example, in an air purifier, indoor dust ("dust" or "dust") is detected.
Products that automatically switch the driving capability based on the results have been commercialized. Such a device is provided with a dust sensor as shown in FIG. 3 for detecting dust. FIG. 3 shows a block diagram around a dust sensor of the air purifier. The dust sensor 10 includes a light emitting unit 20 (active element) formed of an LED and a dust detection unit that receives light from the light emitting unit 20. It comprises a window 24 and a light receiving unit 30 (passive element) that receives light from the light emitting unit 20 reflected on the dust detection window 24. The light emitting section 20 and the light receiving section 30 are connected to a microcomputer 40, respectively. The microcomputer 40 is provided with an active element characteristic detecting means 42 for detecting the characteristic state of the active element. The microcomputer 40 is also connected to a dust collecting section 50.

The operation of the dust sensor 10 having the above configuration will be described below. A pulse signal is output from the microcomputer 40 in the air purifier to the light emitting section 20, and light emission is performed according to the pulse signal. The light emitted here is directed toward the dust detection window 24, and the light reflected by the dust detection window 24 is sent to the light receiving unit 30, but the dust detection window 24 passes through the light receiving unit 30 according to the amount of dust. Since the light reflected by the light changes, the amount of dust in the atmosphere is detected using the light. The light receiving result is output to the microcomputer 40 and converted into a voltage by the active element characteristic detecting means 42, whereby the amount of dust in the air is determined inside the air purifier, and the strength of the dust collecting portion as shown in FIG. Medium, weak, and stop capabilities are controlled.

[0005]

The most important element for detecting dust in the above configuration is the light emitting section 30, that is, the LE.
D is the luminance. However, the characteristics of the dust sensor 40 including the light emitting unit 30 in the initial state vary. The “characteristic in the initial state” indicates an initial characteristic value at the time of production of the dust sensor 40 or in a use state close thereto. That is, the dust sensor 40 converts the amount of dust into a voltage, calculates the amount of dust based on the voltage value, and controls the operation of the air purifier, etc., as described above. Is generated,
Actually, there is a problem that the operation is not performed even when there is dust and the device must be driven, and the operation is performed when the operation is not required. In the dust sensor 40 used for air purifiers, etc.,
As shown in FIG. 2, since the converted voltage uses a delicate value such as about 1/10 volt, the above-mentioned variation is a serious problem. Referring to FIG. 2, what is originally required is an ideal characteristic line, and the setting around the sensor is made according to this ideal characteristic. It often becomes a straight line, and as shown in FIG. 2, the threshold value of each operation mode shifts, so that the operation mode is not properly switched.

As a countermeasure, a high-precision sensor can be used, or the characteristic value of the sensor of each product can be detected and corrected at the time of production. However, both are expensive, and in the latter case, the production efficiency is increased. Is reduced. Therefore, in a conventional device, a desired operation state cannot be realized in many cases.

In the conventional example, an example using an LED has been described. However, a device for controlling an operation state using a sensor composed of a combination of an active element and a passive element (a flame detection using a CDS) may be used. Etc.), there is a problem that the desired operation is hindered by the variation in the characteristics in the initial state.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a sensor correction device which can predict a variation in characteristics of a sensor in an initial state at the time of product design and can reliably realize a desired operation state.

[0009]

According to the present invention, there is provided an ideal characteristic storing means for storing ideal characteristics of an active element, and an active element actual value detecting means for detecting an actual state of the active element. A characteristic comparison means for comparing output characteristics from the ideal characteristic storage device and the active element actual value detection means, and an approximation to an ideal characteristic line by adding a comparison result from the characteristic comparison means to the actual measurement value of the active element. And a calculation means for causing the sensor to be corrected.

[0010]

FIG. 1 is a block diagram showing a peripheral portion of a sensor of an air purifier according to an embodiment of the present invention. In FIG. 1, a microcomputer 40 is provided in the air purifier. In the microcomputer 40, an active element actual measurement value detecting means 42 for detecting a characteristic state of an actual active element is provided. )) Is stored in the ideal characteristic storage means 48.
This output section has the active element actual value detection means 42.
Is a b0-b1 value storage device that holds the difference between the value (b1) detected by the device and the value (b0) held by the ideal characteristic storage means 48.
60 (a non-volatile memory is used in this embodiment). In the microcomputer 40, a characteristic comparison means 44 connected to the active element actual value detection means 42 and the b0-b1 value storage device 60 for comparing the two output characteristics, and a comparison result from the characteristic comparison means 44 Therefore, there is provided a calculating means 46 for adding to the actually measured value of the active element, and this calculating means 46 is connected to a dust collecting section 50 for actually removing dust.

The "ideal value" indicates the original performance of an active element disclosed in a specification or the like issued by an element provider.

In the above configuration, the dust sensor 10 is the same as that described in the above-mentioned prior art. However, if it is described again, the light emitting unit 20 (active element) formed by an LED and the light emitted from the light emitting unit 20 Dust detection window 24 that receives light and dust detection window
And a light receiving unit 30 (passive element) that receives light from the light emitting unit 20 reflected by the light emitting unit 24. The light emitting unit 20 and the light receiving unit 30 are connected to a microcomputer 40, respectively.

The sensor correcting means having the above configuration will be described below. The sensor correction device of the present invention only needs to be set to operate at least at the first energization of the mounted device,
For example, the following operation is performed at the time of production, so that the user does not need to be conscious of such correction.

First, the power is turned on to the device, and the dust in the dust detection window 24 is removed by using the dust collection unit 50 or driving a fan or the like, so that the brightness of only the light emitting unit 20 can be detected. Thereafter, the light emitting section 20 is turned on, and the lighting result (actual measurement value) is output to the active element actual value detection means 42. As described above, the ideal value is stored in the ideal characteristic storage means 48. Here, in the present invention, the output result of the active element measured value detection means 42 is input to the ideal characteristic storage means 48, and the difference is stored in the b0-b1 value storage device 60. Next, when the normal operation is performed, b0-b1 obtained as described above is used.
The contents stored in the value storage device 60 are output to the characteristic comparison means 44, and the characteristic comparison means 44 adds the value of the b0-b1 value storage device 60 to the measured value obtained from the active element measured value detection means 42 to collect the data. The value to be output to the dust part 50 is determined.

The correction means will be described using a straight line as shown in FIG. 2. The ideal characteristic storage means 48 stores the straight line indicated by the ideal characteristic shown in FIG. Is 1.0V. The actual measured value of the dust-free state obtained from the dust sensor 10 is b1, that is, the b1 value that appears in the active element actual measured value detecting means 42 is the actual measured value b1 (0.5 V) of FIG. Become. The difference between the two straight lines is output to the b0-b1 value storage device 60 and stored. When the actual operation starts, the stored difference is processed by the calculating means 46. The processing result here is such that the corrected value is Vp, and an arbitrary part of the actually measured value is obtained. Assuming that VH, Vp = VH + (b0
−b1), and when the value obtained in this way is made a straight line, it becomes very close to the straight line indicated by the ideal characteristic. Therefore, even if the sensor originally has a variation, a characteristic straight line close to or equal to the ideal value can be obtained by comparing and calculating the ideal characteristic and the actually measured value.

In the above description, the ideal characteristic storing means 48, the active element measured value detecting means 42, the characteristic comparing means 44, and the calculating means 46 are provided in the microcomputer 40, but needless to say, they are provided as separate components. In the above embodiment,
LED is used for the active element because it is a light emitting unit, but in a device that controls the driving situation using a sensor composed of a combination of other active elements and passive elements (for example, flame detection using CDS) Even if used, the same effect can be obtained. Further, the threshold values, the values of b0 and b1, and other values used in the above embodiment can be changed as appropriate, and are not limited to those of the present embodiment.

[0017]

According to the above configuration, even if a sensor having a relatively large variation is used, the production efficiency is not reduced.
In addition, since the correction can be automatically performed for each product, a desired operating state can be realized together with accurate sensing.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air purifier according to an embodiment of the present invention.

FIG. 2 is a diagram showing ideal characteristics and actually measured values according to the embodiment of the present invention or the related art.

FIG. 3 is a block diagram of a conventional air purifier.

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. DESCRIPTION OF SYMBOLS 10 Dust sensor 20 Light emitting part 24 Dust detection window 30 Light receiving part 40 Microcomputer 42 Active element actual measured value detecting means 44 Characteristic comparing means 46 Arithmetic means 48 Ideal characteristic storing means 50 Dust collecting part 60 b0-b1 storing part

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI G01N 21/53 G01N 21/53 Z

Claims (3)

[Claims] An ideal characteristic storage means for storing an ideal characteristic of an active element, an active element measured value detecting means for detecting an actual state of the active element, and an ideal characteristic storage device and an active element measured value detecting means. A characteristic comparing means for comparing the output characteristics of the active element and an arithmetic means for approximating an ideal characteristic line by adding the measured value of the active element to the measured value of the active element according to the comparison result from the characteristic comparing means. Correction device. 2. The calculation by the calculation means is performed as follows: Vp = VH + (b
0-b1): Vp is a corrected value, VH is an arbitrary value of an actually measured value, b0 is an ideal characteristic value in a dust-free state, and b1 is an actually measured value in a dust-free state. Sensor correction device. 3. A sensor correction device according to claim 1, wherein the sensor correction device operates only at the first energization of the mounted device.