JPH102755A - Sensor-correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely realize the intended operating state, even in the use of a long period by detecting the characteristic state of an active element, comparing the state with the initial characteristics, stored in an initial-characteristic memory device and performing the addition or subtraction to the present value of the active element. SOLUTION: The pulse signal is outputted from a microcomputer 40 in an air cleaner to a light-emitting part 20, and the light emission of the light-emitting part 20 is performed. The light emission is performed toward a dust-detecting window 24. The light, reflected from the dust detecting window 24, is sent to a light-receiving part 30. The light, which is reflected from the dust-detecting window 24 toward the light- receiving part 30 is changed, according to the much or less amount of dust. This fact is utilized, and the amount of dust in the atmosphere is detected. Then, the lighting result of the light-emitting part 20 is outputted to an active-element-characteristic detecting means 42. At the same time, the information of an initial characteristic memory device 60 is outputted to the microcomputer 40. These values are compared by a characteristic-comparing means 44. When there is a difference between both values, the output characteristics from the light-emitting part 20 is corrected by an operating means 46.

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 performing correction corresponding to deterioration of sensing due to long-term use.

[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. 2 for detecting dust. FIG. 2 is 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 device 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 processed by the active element characteristic detecting means 42, whereby the amount of dust in the air is determined inside the air purifier, and the performance of the dust collecting section is controlled.

[0005]

In the above configuration, the most important factor for detecting dust is the light emitting unit 30, that is, the brightness of the LED. However, during operation of the air cleaner, the LED is always in a driving state. However, there is a problem in that the initial luminance cannot be maintained due to deterioration of the LED due to long-term use, which makes it impossible to accurately detect the amount of dust. That is, it is not possible to determine whether the change in LED brightness is due to dust or deterioration of the LED. Driving with capacity cannot be realized.

In general, the life of such a product is about several years to several tens of years, but it is impossible for a user to periodically maintain and replace such a sensor unit. Therefore, since the user uses the product without being aware of such inconvenience, it is not possible to realize the operation with the desired ability.

In the conventional example, an example using an LED has been described. However, a device for controlling an operating condition using a sensor composed of a combination of an active element and a passive element (flame detection using a CDS) is also used. Etc.), there is a problem that a desired operation is hindered by deterioration of the sensor.

In view of the above problems, an object of the present invention is to provide a sensor correction device which predicts deterioration of a sensor at the time of product design and can reliably realize a desired operation state even during long-term use.

[0009]

According to the present invention, there is provided an initial characteristic storage device for storing initial characteristics of an active element, an active element characteristic detecting means for detecting a characteristic state of the active element, and Characteristic comparing means for comparing output characteristics from the initial characteristic storage device and the active element characteristic detecting means,
A calculating means for adding or subtracting to or from the current value of the active element according to the comparison result from the characteristic comparing means.

[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. The microcomputer 40 includes a dust sensor 10 and an initial characteristic storage device 60 (in this embodiment, an initial value of an active element) forming the dust sensor 10. And a dust collection unit 50 that actually removes dust. In the microcomputer 40, an active element characteristic detecting means 42 for detecting the characteristic state of the active element, a characteristic comparing means 44 for comparing output characteristics from the initial characteristic storage device and the active element characteristic detecting means 42, And an arithmetic means 46 for adding or subtracting to or from the current value of the active element according to the comparison result from the characteristic comparing means 44.

The "initial value of the active element" refers to an initial characteristic value at the time of production of the active element or in a use state close to this.

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 operation of the air purifier having the above configuration will be described below. Light emitting unit from microcomputer 40 in air purifier
A pulse signal is output to 20, and the light emitting unit 20
The light emission is performed in. The emission here is a dust detection window
The light reflected to the dust detection window 24 is sent to the light receiving unit 30, but the light reflected from the dust detection window 24 to the light receiving unit 30 changes according to the amount of dust. This is used to detect the amount of dust in the atmosphere. The light receiving result is output to the active element characteristic detecting means 42 in the microcomputer 40 to control the performance of the dust collecting section 50. The above is the normal operation of the air purifier.

Next, a procedure for correcting the characteristic state of the light emitting section 20 of the dust sensor 10 will be described. First, dust in the dust detection window 24 is removed by using the dust collecting 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 is output to the active element characteristic detecting means 42. At this time the initial characteristic storage device
The information of 60 is output to the microcomputer 40, and the active element characteristic detecting means 42 and the initial characteristic storage device 60 are compared with the characteristic comparing means.
Compare by 44, and if there is a difference between them, the calculation means
The output characteristic from the light emitting unit 20 is corrected by 46, and this correction value is used as the reference value of the light emitting unit 20 from the next time.

In the above description, the active element characteristic detecting means 42, the characteristic comparing means 44, and the calculating means 46 are provided in the microcomputer 40, but they are of course provided as separate components. In the above-described embodiment, the LED is used as the active element because of the light emitting unit. However, a device that controls the driving state using a sensor composed of a combination of another active element and a passive element (for example, a CDS is used. The same effect can be obtained even when used in the detection of a flame to be performed.

[0016]

According to the above configuration, even when the desired sensor characteristics cannot be obtained due to the deterioration of the active element, the user can appropriately maintain the sensor characteristics, so that accurate sensing can be always performed and the desired operation state can be maintained.

[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 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 characteristic detecting means 44 Characteristic comparing means 46 Computing means 50 Dust collecting part 60 Initial characteristic storage device 6

Claims (2)

[Claims] An initial characteristic storage device for storing initial characteristics of an active element, an active element characteristic detecting means for detecting a characteristic state of the active element, and output characteristics from the initial characteristic storage device and the active element characteristic detecting means. And a calculating means for adding or subtracting to or from the current value of the active element according to the comparison result from the characteristic comparing means. 2. The sensor correction device according to claim 1, wherein the initial characteristic storage device is a nonvolatile memory.