WO2011001585A1

WO2011001585A1 - Infrared detection device and non-contact input device

Info

Publication number: WO2011001585A1
Application number: PCT/JP2010/003228
Authority: WO
Inventors: 石川寛人
Original assignee: 株式会社村田製作所
Priority date: 2009-07-03
Filing date: 2010-05-13
Publication date: 2011-01-06
Also published as: JPWO2011001585A1

Abstract

Provided is an infrared detection device whereby, out of movements of infrared radiation emitting bodies such as human bodies, only prescribed movements which are desired to be detected are selectively and reliably detected. An infrared detection device (1) is provided with a dual type pyroelectric infrared sensor (10) and an information processing unit (20). The information processing unit (20) is provided with a peak detection section (24) which chronologically detects the peaks of signals output by the dual type pyroelectric infrared sensor (10); a peak computing device which finds the time interval between a first peak (P1) and a second peak (P2) having different polarities (peak interval), as well as the ratio of the absolute values of both the peaks (peak ratio); a validity determination section (26) which determines whether or not detected results are valid depending on whether or not the peak interval and the peak ratio belong to valid regions; and a movement direction determining section (28) which, if detection results are determined to be valid, determines the movement direction of the pertinent infrared radiation emitting body.

Description

Infrared detector and non-contact input device

The present invention relates to an infrared detection device and a non-contact type input device using the infrared detection device.

Using a pyroelectric infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared rays incident from an infrared emitter such as a human body (hereinafter also simply referred to as “human body”), the presence or absence of the human body and the direction of movement Infrared-type human body detection devices that detect the above have been conventionally known, and are used in the fields of security, home appliances, and the like. As such an infrared human body detection apparatus, Patent Document 1 describes a pyroelectric human body detection apparatus that uses a dual-type pyroelectric infrared sensor to accurately determine a human body and determine a human body movement direction. ing. According to this pyroelectric human body detection device, the output signal from the dual type pyroelectric infrared sensor is amplified and filtered, and then input to a comparison circuit, which is compared with a preset threshold value. When it is larger than the threshold value, a human body detection signal is output. This pyroelectric human body detection device utilizes the feature that the phase of the output waveform of the dual-type pyroelectric infrared sensor is inverted depending on the moving direction of the human body, and either the positive or negative human body detection signal is first sent. The moving direction of the human body is determined depending on whether it has been output.

Patent Document 2 compares the magnitude relationship between the absolute value of the first peak value and the absolute value of the second peak value of the waveform signal output from the dual type pyroelectric infrared sensor. An infrared human body detection apparatus is disclosed that outputs a human body detection signal when the absolute value of the second peak value is larger than the absolute value of the first peak value.

JP-A-10-160856 Japanese Patent No. 3333646

By the way, the output waveform of the dual-type pyroelectric infrared sensor shows the movement of the human body etc. (more specifically, the angle formed with the sensor), the movement form (whether it passed or stopped halfway during passage), etc. It depends on the direction. Even if the movement is the same, the output waveform of the sensor changes depending on conditions such as the temperature of the human body (more specifically, the temperature difference from the surroundings), the distance to the sensor, and the moving speed. In the pyroelectric human body detection device described in Patent Document 1, since a human body detection signal is output only when the output signal from the sensor exceeds a threshold value, a predetermined movement of the human body or the like (for example, a human body or the like is dual). It is difficult to distinguish and detect only the movement of the two pyroelectric elements composing the type pyroelectric infrared sensor along the arrangement direction. In addition, for example, when the temperature difference between the ambient temperature and the human body is small, or when the distance from the sensor is far away, the output signal from the sensor is small, so the human body etc. Regardless, it may not be detected (not detected). However, if the threshold value is reduced here, unnecessary sensor output and noise are captured and erroneous detection is likely to occur.

On the other hand, in the infrared type human body detection device disclosed in Patent Document 2, it is not considered that the magnitude relationship between the peak values changes depending on the moving speed of the human body or the like. For this reason, even if the movement is the same, if the moving speed is fast and the second peak value is smaller than the first peak value, there is a risk of erroneous detection. As described above, in the conventional human body detection device, it is difficult to reliably detect only a predetermined movement of the human body or the like regardless of conditions such as the temperature of the human body, the distance from the sensor, the moving speed, and the like.

The present invention has been made in order to solve the above-described problems, and is an infrared detector capable of selectively and reliably detecting only a predetermined movement to be detected among movements of an infrared radiator such as a human body. An object is to provide a device and a non-contact input device.

An infrared detector according to the present invention has a dual type pyroelectric infrared sensor that has two pyroelectric elements connected in series so that the polarities are reversed, and outputs a detection signal corresponding to the amount of change in infrared, Peak detection means for detecting the peak of the detection signal output from the dual type pyroelectric infrared sensor in time series, and the time between the first peak and the second peak having different polarities detected by the peak detection means A peak calculating means for determining the interval and the ratio of absolute values of both peaks, and a determining means for determining whether the detection signal is valid based on the time interval and the ratio of absolute values determined by the peak calculating means; It is characterized by providing.

As described above, the waveform of the detection signal output from the dual type pyroelectric infrared sensor includes the moving direction of the human body, how to move such as the moving state, the temperature of the human body, the distance from the sensor, the moving speed, etc. Varies depending on the conditions. As the waveform of the detection signal changes, the time interval between the peaks of the waveform (hereinafter also referred to as “peak interval”) and the ratio of the absolute values of both peaks (hereinafter also referred to as “peak ratio”) also change. That is, since the peak interval and the peak ratio change depending on the movement method and conditions described above, it is possible to estimate the movement method and conditions when the detection signal is output by obtaining the peak interval and peak ratio of the detection signal. it can. Here, according to the infrared detection device of the present invention, it is determined whether or not the detection signal is valid based on the time interval between the first peak and the second peak and the ratio of the absolute values of both peaks. Is done. Therefore, it is possible to determine whether or not the detection result is valid, that is, whether or not it is a predetermined movement to be detected, in consideration of the movement method and conditions when the detection signal is output. In addition, according to the infrared detection device of the present invention, the validity of the detection result is determined from the peak interval and the peak ratio, so that no detection or false detection occurs even under conditions where the sensor output is small. Therefore, it is possible to reliably detect the movement of the human body or the like. As a result, it is possible to selectively and reliably detect only a predetermined movement to be detected among movements of an infrared radiator such as a human body.

The infrared detecting device according to the present invention includes a moving direction determining unit that determines a moving direction of the infrared radiator based on the polarity of the first peak when the determining unit determines that the detection signal is valid. It is preferable.

The dual type pyroelectric infrared sensor has a characteristic that the polarity of the detection signal is reversed when the moving direction of the infrared radiator is reversed. Therefore, according to the infrared detection device of the present invention, the moving direction of the infrared radiator can be determined from the polarity of the first peak output first. Therefore, when a predetermined movement of an infrared radiator such as a human body is detected, the moving direction of the infrared radiator can be determined together.

The infrared detection device according to the present invention has an effective region for determining whether or not the detection signal is valid for the time interval between the first peak and the second peak and the ratio of the absolute values of both peaks. Storage means for storing the information to be defined, and the determination means determines whether the ratio between the time interval and the absolute value belongs to the effective area based on the information stored in the storage means, and When it is determined that the detection signal belongs to the area, it is preferable to determine that the detection signal is valid.

In this case, an effective area for validating the detection signal is set for the peak interval and the peak ratio, and information defining the effective area is stored in advance. Therefore, when the detection signal is output, the effectiveness of the detection signal is determined by determining whether the peak interval and the peak ratio of the detection signal belong to the effective region based on information that defines the effective region, That is, it is possible to accurately determine whether or not the movement is desired to be detected.

Further, the effective region has a smaller time interval or a larger ratio of the absolute value of the second peak to the absolute value of the first peak than the invalid region where the detection signal is invalidated. Is preferred.

For example, when the human body moves in a direction parallel to the arrangement direction of pyroelectric elements (hereinafter also referred to as “parallel direction”), the ratio of the absolute value of the second peak to the absolute value of the first peak (peak ratio) ) Tends to increase. At that time, the detection signal decreases as the temperature of the infrared radiator decreases and the distance from the sensor increases, but the peak ratio hardly changes. On the other hand, when the human body moves in a direction perpendicular to the arrangement direction of the pyroelectric elements (hereinafter referred to as “vertical direction”) or stops on the sensor, the peak ratio tends to be small. Furthermore, as the moving speed increases, the peak interval and the peak ratio tend to decrease under all conditions. Therefore, by setting a region with a smaller peak interval or a region with a larger peak ratio as an effective region, the detection result can be obtained regardless of conditions such as temperature, distance, and speed only when the human body moves in the parallel direction. It can be determined that (detection signal) is valid. That is, when the human body moves in the vertical direction or stops halfway, the detection result can be determined to be invalid.

A non-contact type input device according to the present invention is generated by any one of the above infrared detection devices, an operation signal generation unit that generates an operation signal of an electronic device based on an output from the infrared detection device, and an operation signal generation unit And an operation signal output means for outputting the operated operation signal to an electronic device.

According to the non-contact input device according to the present invention, an operation signal of the electronic device is generated and output based on the movement of the operator detected by the infrared detection device. At that time, by using any one of the infrared detection devices described above, it is possible to selectively detect only a predetermined movement to be detected. Therefore, by directly associating a predetermined movement with an operation signal, it can be directly performed by hand. Electronic devices can be operated without touching.

According to the present invention, it is configured to determine whether or not the detection signal is valid based on the time interval between the first peak and the second peak having different polarities and the ratio of the absolute values of both peaks. Therefore, it is possible to selectively and surely detect only a predetermined movement to be detected among movements of an infrared radiator such as a human body.

It is a block diagram which shows the structure of the infrared rays detection apparatus which concerns on embodiment. It is a figure which shows the relationship between the moving direction of an infrared radiation body, and the output waveform of a dual type pyroelectric infrared sensor. It is a figure which shows an example of the output waveform of a dual type pyroelectric infrared sensor, and the 1st peak and 2nd peak of this output waveform. It is a figure which shows the relationship between a movement method and conditions, and the output waveform of a dual type pyroelectric infrared sensor. It is a figure which shows an example of the boundary line which divides both the effective area | region and invalid area | region defined by a peak space | interval and a peak ratio, and both area | regions. It is a flowchart which shows the process sequence of the infrared radiation body detection process by the infrared rays detection apparatus which concerns on embodiment, and a moving direction determination process. It is a block diagram which shows the structure of the non-contact-type input device which concerns on embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

First, the configuration of the infrared detection device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of the infrared detection device 1.

The infrared detecting device 1 selectively detects only a predetermined movement to be detected (or an infrared radiator such as a human body that has performed the predetermined movement) among movements of an infrared radiator such as a human body, and a direction of the movement. (Moving direction) is detected. For this purpose, the infrared detection device 1 is a dual type pyroelectric infrared sensor (hereinafter simply referred to as “a detection signal”) that outputs an electrical signal (detection signal) corresponding to the amount of change in infrared rays incident from a human body (including a part of the human body). 10) and an information processing unit 20 that processes detection signals output from the dual type pyroelectric infrared sensor 10 to detect the presence or absence of a predetermined movement and the moving direction. The information processing unit 20 includes an amplification unit 21, a bandpass filter 22, an A / D conversion unit 23, a peak detection unit 24, a peak calculation unit 25, an effectiveness determination unit 26, a storage unit 27, and a movement direction determination unit 28. Have. Hereinafter, each configuration will be described in detail.

As shown in FIG. 2, the dual type pyroelectric infrared sensor 10 includes two

pyroelectric elements

10a and 10b connected in series so that the polarities are reversed. A differential signal of the amount of change in infrared rays incident on each of 10a and 10b is output as a detection signal. Therefore, the dual type pyroelectric infrared sensor 10 has a characteristic that the polarity of the detection signal is reversed when the moving direction of the human body or the like is reversed. More specifically, as shown in FIG. 2, when a human body or the like moves in the direction of arrow A1 along the direction parallel to the arrangement direction of the two

pyroelectric elements

10a and 10b, the output waveform is first positive. Rise in the direction and then reverse in the negative direction. Conversely, when a human body or the like moves in the direction of arrow A2, the output waveform falls in the negative direction and then reverses in the positive direction. The dual type pyroelectric infrared sensor 10 is connected to the information processing unit 20, and a detection signal is output to the information processing unit 20.

As described above, the information processing unit 20 processes the detection signal input from the dual type pyroelectric infrared sensor 10 to determine the presence / absence of a predetermined movement and the direction (movement direction) of the movement. . The information processing unit 20 performs arithmetic processing on the detection signal input via the amplification unit 21, the band pass filter 22, the A / D conversion unit 23, and the A / D conversion unit 23 as an input interface. It is composed of a microprocessor, a ROM that stores programs and data for causing the microprocessor to execute each process, a RAM that temporarily stores various data such as calculation results, and a backup RAM in which data is backed up. Yes. In the information processing unit 20, the functions of the peak detection unit 24, the peak calculation unit 25, the validity determination unit 26, and the movement direction determination unit 28 are realized by executing the program stored in the ROM by the microprocessor. Is done. Note that the microprocessor, the ROM, the RAM, and the like may be constituted by independent chips, or may be constituted by a microcomputer (microcomputer) housed in one chip.

The amplifying unit 21 is configured by an amplifier using an operational amplifier, for example, and amplifies the detection signal output from the dual type pyroelectric infrared sensor 10 (amplifies by 390 times in this embodiment). The detection signal amplified by the amplifying unit 21 is output to a band pass filter (band filter) 22.

The band pass filter 22 removes unnecessary frequency components (noise components) from the detection signal output from the amplification unit 21. In this embodiment, a bandpass filter having a passband of 1 Hz to 30 Hz is used. In addition, it is good also as a structure which removes noise by performing a filtering process using a digital filter after A / D conversion. The detection signal output from the band pass filter 22 is output to the A / D conversion unit 23.

The A / D converter 23 is composed of an A / D converter, and converts the detection signal (analog signal) output from the bandpass filter 22 into digital data at a predetermined sampling period (480 Hz in the present embodiment). The digitally converted detection signal is output to the peak detector 24.

The peak detector 24 detects the peaks of the captured detection signals in time series. The peak detection unit 24 acquires the detected peak value and time. That is, the peak detection unit 24 functions as a peak detection unit described in the claims. More specifically, the peak detection unit 24 reads the A / D value that has been read and the maximum held in the RAM each time an A / D converted value is read from the initialized (reset) state. The value is compared and the larger value is held as a new maximum value (peak hold). Then, the maximum value is sequentially updated, the maximum value held when the A / D value starts to decrease is set as a peak, and the maximum value is set as the peak value. The peak detection unit 24 performs the peak detection process on the detection signal waveform, thereby acquiring two peaks having different polarities, that is, a positive peak and a negative peak in time series. Here, as shown in FIG. 3, the first detected peak is defined as a first peak P1, and the next detected peak is defined as a second peak P2. FIG. 3 is a diagram illustrating an example of the detection signal and the first peak P1 and the second peak P2 of the detection signal.

In addition to the peak value y1 of the first peak P1 and the peak value y2 of the second peak P2, the peak detector 24 temporarily acquires the time t1 of the first peak P1 and the time t2 of the second peak P2. To remember. In this embodiment, the number of A / D conversion samplings is used as the peak time. That is, since the A / D conversion is performed at a constant sampling period (480 Hz in the present embodiment), the number of times the A / D conversion is performed (sampling number) is counted, and the peak is detected. The counter value of is acquired as time. Therefore, the unit of time (1LSB) is 1 / sampling period (1/480) second. The peak value y1 and time t1 of the first peak P1 and the peak value y2 and time t2 of the second peak P2 detected by the peak detector 24 are output to the peak calculator 25.

By the way, as described above, the output waveform of the dual type pyroelectric infrared sensor 10 includes the moving direction of the human body (an angle formed with the sensor 10), the moving form (whether it has passed or stopped halfway while passing) It depends on how you move. Even if the way of movement is the same, the output waveform of the sensor 10 changes depending on conditions such as the temperature of the human body (temperature difference from the surroundings), the distance to the sensor 10, and the moving speed. Here, the relationship between the way of movement and conditions and the output waveform (detection signal) of the dual type pyroelectric infrared sensor 10 is shown in FIG. FIG. 4A shows a case where a human hand is moved in a direction (parallel direction) parallel to the arrangement direction of the

pyroelectric elements

10a and 10b at a short distance of the sensor 10 (hereinafter also referred to as “case (A)”). The output waveform of is shown. 4A to 4E show output waveforms when the hand is moved at a low speed, at a medium speed, and at a high speed in order from the left side of the drawing. FIG. 4B shows an output waveform when the hand temperature is lower than (A) (hereinafter also referred to as “case (B)”). FIG. 4C shows an output waveform when the distance between the hand and the sensor 10 is far from (A) (hereinafter also referred to as “case (C)”). FIG. 4D shows a case where a human hand is moved in a direction (vertical direction) perpendicular to the arrangement direction of the

pyroelectric elements

10a and 10b at a short distance of the sensor 10 (hereinafter also referred to as “case (D)”). The output waveform of is shown. FIG. 4E shows an output waveform when the hand is moved in the parallel direction at a short distance of the sensor 10 and stopped on the sensor (hereinafter also referred to as “case (E)”).

As shown in FIG. 4, when the hand is moved in the parallel direction, the absolute value | y2 | of the second peak P2 is larger than the absolute value | y1 | of the first peak P1. Tend. At that time, the amplitude of the output waveform decreases as the temperature of the hand decreases and the distance between the hand and the sensor 10 increases. On the other hand, when the hand is moved vertically or stopped on the sensor, the absolute value | y2 | of the peak value of the second peak P2 with respect to the absolute value | y1 | of the peak value of the first peak P1. Tends to be smaller. In addition, the higher the speed at which the hand is moved, the smaller the amplitude of the output waveform under all conditions, and the absolute value of the peak value of the second peak P2 relative to the absolute value | y1 | of the peak value of the first peak P1. The value | y2 | tends to decrease. Note that the peak interval (t2-t1) decreases as the speed at which the hand is moved increases.

The peak calculator 25 detects the time interval (peak interval) (t2-t1) between the first peak P1 (t1, y1) and the second peak P2 (t2, y2) detected by the peak detector 24, and The ratio (peak ratio) (| y2 | / | y1 |) of the absolute value | y2 | of the peak value of the second peak P2 to the absolute value | y1 | of the peak value of the first peak P1 is obtained. That is, the peak calculation unit 25 functions as a peak calculation unit described in the claims. The peak interval (t2-t1) and peak ratio (| y2 | / | y1 |) obtained by the peak calculation unit 25 are output to the validity determination unit 26.

Based on the peak interval (t2−t1) and the peak ratio (| y2 | / | y1 |) obtained by the peak calculation unit 25, the validity determination unit 26 determines whether the detection signal is valid (that is, the detection signal). Whether or not the movement is desired. More specifically, the validity determination unit 26 is based on information that defines an effective region for determining whether or not a detection signal is valid, which is stored in a storage unit 27 that includes a ROM. , The peak interval (t2−t1) and the peak ratio (| y2 | / | y1 |) are determined whether or not they belong to the effective region, and when it is determined that they belong to the effective region, the detection signal Is determined to be effective. That is, the validity determination unit 26 functions as a determination unit described in the claims.

Here, with reference to FIG. 5, a description will be given of an effective region defined by the peak interval (t2-t1) and the peak ratio (| y2 | / | y1 |) and a method for setting information defining the effective region. FIG. 5 is a diagram illustrating an example of an effective area and an ineffective area defined by a peak interval (t2-t1) and a peak ratio (| y2 | / | y1 |), and an example of a boundary line that divides both areas. Here, first, in the five cases shown in the cases (A) to (E) described above, an output waveform is acquired by changing the moving speed, a peak is detected, and a point (t2-t1) is detected for each output waveform. , | Y2 | / | y1 |) is plotted to obtain the distribution shown in FIG. In FIG. 5, the horizontal axis (X-axis) is the peak interval (t2-t1), the vertical axis (Y-axis) is the peak ratio (| y2 | / | y1 |), and the result of the case (A) described above is “+ ”, The result of case (B) is plotted with“ × ”, the result of case (C) is“ * ”, the result of case (D) is“ □ ”, and the result of case (E) is plotted with“ ■ ”. Incidentally, the unit of the horizontal axis (X axis) is 1/480 seconds.

Here, in the case (B) and the case (C), the peak values y1 and y2 are smaller than the case (A), but the peak ratio (| y2 | / | y1 |) shows almost the same value. In the case (D), the peak interval (t2-t1) is slightly wider and the peak ratio (| y2 | / | y1 |) tends to be smaller than in the cases (A), (B), and (C). Case (E) tends to have a smaller peak ratio (| y2 | / | y1 |) than cases (A), (B), and (C). Therefore, for each of the cases (A) to (E), the point (t2-t1, | y2 | / | y1 |) specified by the peak interval (t2-t1) and the peak ratio (| y2 | / | y1 |) ), The results of cases (A), (B), and (C) are distributed in the upper left part of FIG. 5, and the results of cases (D) and (E) are distributed in the lower right part of FIG. .

Therefore, for example, the cases (A), (B), and (C) of the obtained distribution are valid (that is, the movement in the parallel direction is valid), and the cases (D) and (E) are invalid (vertical direction). The following equations (1) and (2) are set as equations for distinguishing the cases (A), (B), and (C) from the cases (D) and (E). (See the dashed line in FIG. 5). Expressions (1) and (2) correspond to “information defining an effective area” described in the claims, and are stored in the storage unit 27. In addition, this effective area | region and Formula (1) (2) are illustrations, It can set arbitrarily, without being restricted to these.
| Y2 | / | y1 |> (2.6 / 50) * {(t2-t1) -25} (1)
However, when (t2−t1) <50 | y2 | / | y1 |> 1.3 (2)
However, when (t2-t1) ≧ 50

Then, the validity judgment unit 26 determines a point (t2-t1) determined by the peak interval (t2-t1) between the two peaks P1 and P2 extracted from the output waveform and the peak ratio (| y2 | / | y1 |). , | Y2 | / | y1 |) determines whether or not the detection result (detection signal) belongs to the effective region depending on whether or not the expression (1) or (2) is satisfied. If it belongs to the effective area, it is determined to be effective as a hand movement. Note that the determination result by the validity determination unit 26 is output to the movement direction determination unit 28.

The movement direction determination unit 28, when the validity determination unit 26 determines that the detection signal is valid, that is, when the point (t2-t1, | y2 | / | y1 |) is included in the valid region. In addition, the moving direction of the human body or the like is determined based on the polarity (positive / negative) of the first peak P1. That is, the movement direction determination unit 28 functions as a movement direction determination unit described in the claims. Information indicating the movement direction determined by the movement direction determination unit 28 is output together with information indicating the presence or absence of a predetermined movement.

Next, the operation of the infrared detection device 1 will be described with reference to FIG. FIG. 6 is a flowchart showing a processing procedure of infrared emitter detection processing and movement direction determination processing by the infrared detection device 1. This process is repeatedly executed in the information processing unit 20 at a predetermined cycle (480 Hz).

First, in step S100, the detection signal output from the dual type pyroelectric infrared sensor 10 is amplified by the amplifying unit 21, filtered by the band pass filter 22, and then converted into digital data by the A / D converting unit 23. Converted and read. Next, in step S102, the peak of the read detection signal is detected. In step S102, the detected peak value and time are acquired. Since the peak detection method is as described above, detailed description thereof is omitted here.

Subsequently, in step S104, it is determined whether or not two peaks having different polarities, that is, a positive peak and a negative peak are acquired. Here, when two peaks are acquired, the process proceeds to step S106. On the other hand, when two peaks have not yet been acquired, the process proceeds to step S100, and the above-described processes of steps S100 to S104 are repeatedly executed until two peaks are acquired.

When two peaks having different polarities are acquired, in step S106, a peak interval (t2-t1) between the two peaks, that is, the first peak P1 (t1, y1) and the second peak P2 (t2, y2). ) And peak ratio (| y2 | / | y1 |).

Subsequently, in step S108, a point (t2-t1, | y2 | / | y1 |) determined by the peak interval (t2-t1) obtained in step S106 and the peak ratio (| y2 | / | y1 |). However, whether or not the detection signal belongs to the effective region is determined depending on whether or not Expression (1) or Expression (2) described above is satisfied. Here, when it is determined that the detection signal belongs to the effective region, it is determined that the detection result is effective as a hand movement, and the process proceeds to step S110. On the other hand, when it is determined that the detection signal does not belong to the valid area, it is determined that the detection result is invalid, and the process is temporarily exited.

If it is determined to be effective in step S108, in step S110, the moving direction of the hand or the like (see FIG. 2) is determined based on the polarity of the first peak P1. Then, information indicating the moving direction is output together with information indicating that the movement in the parallel direction is detected. Thereafter, the process is temporarily exited.

According to the present embodiment, whether or not the detection signal is valid is determined based on the peak interval between the first peak P1 and the second peak P2 and the peak ratio of both peaks. Therefore, it is possible to determine whether or not the detection result is valid in consideration of the movement and conditions of the infrared radiator, that is, whether or not the movement is in the parallel direction to be detected. In addition, according to the present embodiment, the validity of the detection result is determined from the peak interval and the peak ratio, so even in a case where the sensor output is small, there is no undetected or erroneous detection. It is possible to detect movement. As a result, it is possible to selectively and reliably detect only the movement in the parallel direction regardless of the conditions (the temperature of the infrared radiator, the distance to the sensor 10 and the moving speed).

According to the present embodiment, the polarity of the first pyroelectric infrared sensor 10 that is output first is utilized using the characteristic of the dual-type pyroelectric infrared sensor 10 that the polarity of the detection signal is reversed when the moving direction of the infrared radiator is reversed. The moving direction can be determined from Therefore, when the movement in the parallel direction is detected, it is possible to determine the moving direction together.

According to the present embodiment, an effective area in which the detection signal is valid is set for the peak interval and the peak ratio, and a calculation formula that defines the effective area is stored in advance. Therefore, when the detection signal is output, by determining whether or not the peak interval and the peak ratio of the detection signal belong to the effective region based on this calculation formula, the validity of the detection result, that is, It is possible to accurately determine whether or not the movement is in the parallel direction to be detected.

In addition, according to the present embodiment, the region where the peak ratio is large, or the peak ratio is such that the detection result when the infrared radiator moves in the parallel direction and the detection result when the infrared radiator moves in the vertical direction can be distinguished. Since a small area with a small peak interval is set as an effective area, the detection result can be determined to be valid only when moving in the parallel direction regardless of conditions such as temperature, distance, and speed. That is, when the sensor moves in the vertical direction or stops on the sensor, it is possible to determine that the detection result is invalid.

The infrared detection device 1 described above can be used as a non-contact input interface that is connected to an electronic device and inputs an operation signal to the electronic device. Next, the non-contact input device 2 using the infrared detection device 1 will be described with reference to FIG. FIG. 7 is a block diagram showing a configuration of the non-contact input device 2. In FIG. 7, the same or equivalent components as those of the infrared detecting device 1 are denoted by the same reference numerals.

The non-contact type input device 2 is connected to the electronic device 3 in a wired or wireless manner, detects the movement of the operator's hand, etc., and generates and outputs an operation signal corresponding to the detected movement. The electronic device 3 can be operated without touching 3. Therefore, the non-contact input device 2 includes an information processing unit 30 instead of the information processing unit 20 described above. In addition to the configuration of the information processing unit 20, the information processing unit 30 further includes an operation signal generation unit 31 and an operation signal output unit 32. The other configuration is the same as or similar to that of the information processing unit 20 described above, and thus a duplicate description is omitted here.

The operation signal generation unit 31 generates an operation signal for the electronic device 3 based on information indicating the movement direction of the hand or the like output from the movement direction determination unit 28 constituting the infrared detection device 1. The operation signal output unit 32 outputs the operation signal generated by the operation signal generation unit 31 to the electronic device 3. That is, the operation signal generation unit 31 functions as an operation signal generation unit described in the claims, and the operation signal output unit 32 functions as an operation signal output unit described in the claims. Thereby, the operator can operate the electronic device 3 by, for example, the movement of the hand without touching the electronic device 3. Therefore, it is particularly useful in situations where it is desired to operate the electronic device 3 without touching it for the purpose of hygiene and prevention of electric shock. Note that the non-contact input device 2 and the electronic device 3 may be separated from each other, or may be housed integrally in one housing. Further, when the non-contact input device 2 and the electronic device 3 are integrally configured, the information processing unit 30 constituting the non-contact input device 2 is constructed by a microcomputer provided in the electronic device 3. Also good.

Here, examples of the electronic device 3 to which the non-contact input device 2 is applied include a lighting fixture, a telephone, a digital photo frame, and an AV (Audio Visual) device. In that case, for example, lighting equipment ON / OFF operation, telephone incoming call response, digital photo frame photo sending / returning, AV device playback / stop / mode switching, etc. can be performed without contact.

According to the present embodiment, the operation signal of the electronic device 3 is generated and output based on the movement of the operator detected by the infrared detection device 1. At that time, since only a predetermined motion to be detected can be selectively detected, the electronic device 3 can be operated without touching it directly by associating the predetermined motion with an operation signal in advance. It becomes possible.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above embodiment, the ratio (| y2 | / | y1 |) of the absolute value of the second peak P2 to the absolute value of the first peak P1 is used as the peak ratio, but instead of this, the first peak The ratio (| y1 | / | y2 |) of the absolute value of P1 to the absolute value of the second peak P2 may be used as the peak ratio.

In the above embodiment, the calculation formula is used to determine whether the detection result belongs to the effective region. Instead of the calculation formula, the peak interval (t2-t1) and the peak ratio (| y2 | / | Y1 |) For example, a map in which the effective area is “1” and the invalid area is “0” is set in advance, and whether or not the detection result is valid using this map It may be configured to determine. In this way, the degree of freedom for setting the effective range can be improved. In this case, the map corresponds to “information defining an effective area” described in the claims.

In the above-described embodiment, the movement in the parallel direction is enabled. However, the effective movement (effective area) is not limited to the above-described embodiment, and can be arbitrarily set according to the movement / condition to be detected. .

In the above embodiment, the number of times A / D conversion has been performed is counted and the number of counts is used as the time. Good.

In the above embodiment, the number of the dual-type pyroelectric infrared sensors 10 is one. However, a combination of a plurality of sensors may be used to detect a two-dimensional or three-dimensional movement.

DESCRIPTION OF SYMBOLS 1 Infrared detector 2 Non-contact-type input device 3 Electronic device 10 Dual type pyroelectric

infrared sensor

10a,

10b Pyroelectric element

20, 30 Information processing unit 21 Amplification part 22 Band pass filter 23 A / D conversion part 24 Peak detection part 25 Peak calculation unit 26 Effectiveness determination unit 27 Storage unit 28 Movement direction determination unit 31 Operation signal generation unit 32 Operation signal output unit

Claims

A dual-type pyroelectric infrared sensor having two pyroelectric elements connected in series so that the polarities are reversed, and outputting a detection signal according to the amount of change in infrared;
Peak detection means for detecting the peak of the detection signal output from the dual type pyroelectric infrared sensor in time series;
A peak calculating means for obtaining a time interval between a first peak and a second peak having different polarities detected by the peak detecting means and a ratio of absolute values of both peaks;
An infrared detection apparatus comprising: a determination unit that determines whether or not the detection signal is valid based on a ratio between the time interval and the absolute value obtained by the peak calculation unit.
A moving direction determining unit that determines a moving direction of an infrared emitter based on the polarity of the first peak when the determining unit determines that the detection signal is valid. Item 2. The infrared detection device according to Item 1.
A memory for storing information defining an effective region for determining whether or not the detection signal is effective with respect to a time interval between the first peak and the second peak and a ratio of absolute values of both peaks. With means,
The determination means determines whether the ratio of the time interval and the absolute value belongs to the effective area based on the information stored in the storage means, and belongs to the effective area 3. The infrared detection device according to claim 1, wherein when it is determined, the detection signal is determined to be valid.
The effective region has a smaller time interval or a larger ratio of the absolute value of the second peak to the absolute value of the first peak than the invalid region where the detection signal is invalidated. The infrared detection device according to claim 3, wherein
An infrared detection device according to any one of claims 1 to 4;
Based on the output from the infrared detection device, an operation signal generating means for generating an operation signal of the electronic device,
An operation signal output unit that outputs the operation signal generated by the operation signal generation unit to the electronic device.