JP2014089164A - Infrared detector, and display unit and personal computer having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared detector capable of detecting the existence of a detection object in a detection range since the time immediately after the infrared detector starts.SOLUTION: An infrared detector detects the existence of a detection object 6 on the basis of a signal detected by an infrared detection section 100 for outputting a signal corresponding to the quantity of incident infrared radiation. The infrared detection section 100 includes a plurality of infrared sensors 1 and 2 capable of detecting the absolute value of the quantity of incident infrared radiation. Detection ranges A and B set by respective infrared sensors 1 and 2 establish a condition in which virtual outer circumferential lines 4 and 5 of respective virtual projection planes 11 and 12 projected as the detection ranges A and B on a virtual plane 13 facing the infrared detection section 100 do not match with each other.

Description

  The present invention relates to an infrared detection device, a display including the infrared detection device, and a personal computer. More specifically, the present invention relates to an infrared detection device including an infrared sensor and a signal processing unit, a display (character / image display device) including the infrared detection device, and a personal computer. . In particular, the present invention relates to an infrared detection device applicable to a human body detection device whose infrared detection target is a human body.

  2. Description of the Related Art Conventionally, human sensors that detect the presence or absence of a person by detecting infrared rays from a human body are used in various scenes such as automatic lighting / extinguishing of lighting lamps, televisions, displays, and personal computer screens. The purpose of adding a human function to these devices is firstly the purpose of power saving (energy saving) and secondly the purpose of security guard. The first power saving purpose is to eliminate the waste of leaving the lighting, air conditioner and TV etc. in the room without people, and the second security guard purpose is for the personal computer that the user leaves This is to prevent unauthorized operation of a third party or unauthorized browsing / theft of information. In order to meet these purposes, the presence sensor determines the presence or absence of a person, and when it is determined that the person is absent, it turns off the lighting, air conditioner, TV, etc. to be controlled from the on state and locks the functions of the personal computer. Therefore, it is desired to appropriately restrict functions.

  As such a human sensor, a sensor that detects infrared rays emitted from a person who is a detection target is known, and among them, a pyroelectric sensor is widely used. The pyroelectric sensor outputs an electrical signal corresponding to the amount of change in infrared energy incident on the sensor. For example, when a person to be detected enters the detection range, the amount of infrared energy in the detection range changes before and after the entry, so that an electric signal corresponding to the change is output to detect the intrusion of the person. Is possible.

However, when a person continues to stand still in the detection range, the amount of infrared rays incident on the sensor hardly changes. Therefore, the electrical signal output from the pyroelectric sensor that outputs an electrical signal in accordance with the change has a slight value, which makes it difficult to detect the person who is the detection target.
Therefore, when the pyroelectric sensor is used for human detection, there are some which alleviate the above drawbacks by using it in combination with a timer. As an example, a power-saving device that automatically turns on / off an illumination lamp by combining a human sensor and a timer is known. In the power-saving device, once the pyroelectric sensor detects a person who is a detection target, the illumination lamp continues to be lit during the time set by the timer. When the movement of the person who is the detection target is detected again within the timer set time, the lighting state is continued by resetting the timer. If a person leaves the detection range, no output from the pyroelectric sensor can be obtained, and the light is automatically turned off when the timer setting time is reached.

In this way, even in the detection range, even when a person sits on a chair and hardly moves, and the output signal of the pyroelectric sensor becomes small, it is set in advance by combining the pyroelectric sensor and the timer. Since the illumination lamp continues to be lit until a certain period of time, even if the illumination lamp does not move for a while, the probability that the illumination lamp will turn off without permission can be reduced.
However, if the person who is the detection target continues for a longer time than the set time of the timer, there is a drawback that it is erroneously determined that the detection target person is absent even if the detection target person exists in the detection range. In order to avoid this drawback, if the timer setting time is increased, the lighting state will continue for a long time despite the absence of the timer, and the original purpose of power saving (energy saving) with the presence sensor installed. It will be contrary to.

  As an infrared sensor other than the pyroelectric sensor that outputs an electric signal corresponding to a change, there are a thermopile and a quantum infrared sensor that can detect the absolute amount of incident infrared rays (hereinafter also referred to as an absolute infrared amount sensor). . This absolute infrared ray amount sensor can detect an absolute value of infrared rays corresponding to a temperature difference between a person who is a detection target and the sensor itself. Therefore, the detection output for the stationary detection target person can be used as it is, and it is not necessary to combine with a timer.

  For example, the one described in Patent Document 1 uses the above-described absolute infrared amount sensor, and detects an indoor temperature distribution and the presence and behavior of a human body by a simple configuration, control, and signal processing compared to the conventional one. System. Specifically, an infrared sensor that combines a thermopile and a pyroelectric infrared detector so that the indoor temperature distribution detection range and the human body detection range are the same range, a thermopile signal processor, and a pyroelectric infrared detector signal Processing unit, vertical driving means and horizontal driving means for scanning the infrared sensor in the vertical and horizontal directions, vertical / horizontal driving control section for controlling the vertical driving means and the horizontal driving means, and infrared sensor information by range It consists of a storage unit.

  Moreover, the thing of patent document 2 is an infrared sensor which detects the infrared rays which a human body emits with high sensitivity efficiently, without requiring a special cooling device. Specifically, the detection unit and the non-detector that configure the single sensor so that the ratio of the area of the detection unit to the area of the non-detection unit that configures the single sensor for obtaining a predetermined aperture ratio becomes a predetermined value. In the connection between two single sensors adjacent to each other in the same row on the support substrate, the planar shape of the detection unit is formed into a polygonal shape of a pentagon or more that does not have an angle less than a right angle. The non-detection part of the single sensor and the detection part of the single sensor on the downstream side are wired so as to be connected in series, and arranged between two adjacent single sensors in the same row on the support substrate. The detection units constituting the single sensor in one row and the non-detection portions constituting the single sensor in the other row are alternately arranged.

Next, the simplest principle of operation using an infrared sensor capable of detecting a stationary object will be described.
FIG. 1 is a graph illustrating output characteristics when an infrared sensor detects a person to be detected in a conventional infrared detection device. The vertical axis in FIG. 1 indicates the value of the electrical signal output from the infrared sensor, and the horizontal axis in FIG. 1 indicates time. When the person who is the detection target is not present in the detection range, the quantum infrared sensor receives infrared radiation from the background such as the wall or floor of the detection range. At this time, the infrared sensor outputs a value corresponding to the temperature difference between the background temperature and the sensor itself.

  Next, a case where a person who is a detection target enters and exits the detection range will be described. The person to be detected by the infrared sensor has a substantially constant body temperature. In particular, the temperature of the exposed part of the skin such as a human face is about 34 ° C., which is higher than the normal room temperature (for example, 25 ° C.). Therefore, when the person who is the detection target enters the detection range, the output value of the infrared sensor increases. When the intruder is out of the detection range, the output value of the infrared sensor returns to the level corresponding to the background temperature again. Therefore, a threshold value (fixed), which is a criterion for determining whether or not a detection target exists, that is, whether or not a person is present in the detection range, is set as shown in FIG. 1, and the magnitude relationship between the threshold value and the output value of the infrared sensor. It is possible to determine whether or not there is a person in the detection range. That is, the section Z shown in FIG. 1 is a section in which it is determined that the person to be detected is present.

2006-226988 2007-081225

However, even when an absolute infrared amount sensor such as a quantum infrared sensor is used as described above, the output value of the infrared sensor for a certain period of time is observed, and the output between section Z and other sections is compared. Since it is necessary to perform this, it is impossible to detect the presence or absence of the detection target in the detection range immediately after the infrared detection device is activated.
The present invention has been made in view of such problems, and an object of the present invention is to provide an infrared detection device capable of determining the presence or absence of a detection target in a detection range immediately after the infrared detection device is activated. The purpose is to provide.

  The present embodiment has been made to achieve such an object, and the invention according to claim 1 is detected by the infrared detector (100) that outputs a signal corresponding to the amount of incident infrared rays. In the infrared detection device that detects the presence or absence of the detection object (6) based on the signal, the infrared detection unit (100) includes a plurality of infrared sensors capable of detecting an absolute value of the amount of incident infrared rays ( 1), and each detection range (A, B) set in the infrared sensor (1, 2) is placed on a virtual plane (13) facing the infrared detection unit (100). It is characterized by satisfying the condition that the virtual perimeter lines (4, 5) bordering the virtual projection planes (11, 12) projected as the detection ranges (A, B) do not coincide with each other. (Figure 2)

According to a second aspect of the present invention, in the first aspect of the invention, the infrared detector (100) has a detection angle that spreads forward from the light receiving surface (3) of the infrared sensor (1, 2). And a detection angle limiting body (20) that limits each detection range (A, B) of the infrared sensor (1, 2) by narrowing in the vicinity of the light receiving surface (3). 20) is characterized by comprising an infrared shielding part (23) having a light shielding property and an infrared transmitting part (24) having a light transmitting property. (Fig. 2, Fig. 6)
The invention according to claim 3 is the invention according to claim 2, wherein the detection angle limiter (20) includes an infrared transmission part (24) formed in a single window shape, and the infrared transmission part. It is characterized by comprising an infrared light shielding part (23) surrounding (24) in a window frame shape. (Fig. 2, Fig. 6)

According to a fourth aspect of the present invention, in the invention according to the first, second, or third aspect, the signal processing unit (10) is a detection target in a detection region including the detection ranges (A, B). It is possible to determine whether or not the object (6) exists, and as a result of comparing the output of each detection signal of the infrared sensor (1, 2), it is detected from the detection object (6). When the ratio of the infrared rays to be different is different, it is possible to obtain a determination result that the detection object (6) exists in the detection region including the detection ranges (A, B). (FIGS. 1, 3, 7, 8, and 9)
According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the signal processing unit is configured to detect an object based on a difference in output of the infrared sensors (1, 2) or a ratio of the outputs. It is characterized by determining the presence or absence of (6). (FIGS. 3, 7, 8, and 9)
According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the infrared sensor (1, 2) has a vertical distance (J, It is characterized by being arranged with a predetermined separation distance (d) so that K) is different. (Fig. 3, Fig. 7)

The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the infrared sensor (1, 2) is parallel to the ground (G) or the floor (F). It is characterized by being arranged with a predetermined separation distance (d) in the direction. (FIGS. 2, 5, and 6)
The invention according to claim 8 is characterized in that, in the invention according to any one of claims 1 to 7, the detection object (6) is a human body that emits infrared rays. (Figure 3)
The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the infrared sensor (1, 2) is formed on the same substrate (19). To do. (Fig. 5)
The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the infrared sensor (1, 2) is a quantum infrared sensor.

An eleventh aspect of the invention includes the infrared detection device according to any one of the first to tenth aspects, an image display section (83), and a frame section (81) surrounding the image display section (83). In the display (80) having the above, the infrared detection device is connected to the frame (81) so that a straight line (C) connecting the infrared sensors (1, 2) is parallel to the frame (81). ). (Figure 3)
The invention according to claim 12 is the invention according to claim 11, wherein the straight line (C) connecting the infrared sensors is parallel to the vertical frame portion (82) of the display (80). It is characterized by. (Figure 3)
A thirteenth aspect of the present invention is a personal computer (90) comprising the infrared detecting device according to any one of the first to tenth aspects. (Figure 3)
The invention described in claim 14 is a personal computer (90) comprising the display (80) according to claim 11 or 12. (Figure 3)

  According to the present invention, an infrared detection device, a display including the infrared detection device, and a personal computer, more specifically, an infrared detection device including an infrared sensor and a signal processing unit, a display (character / image display device) including the infrared detection device, and a personal computer In this case, it is possible to realize an infrared detection device capable of determining the presence or absence of a detection target in the detection range immediately after the infrared detection device is activated. Further, the present invention can be applied to a human body detection device whose infrared detection target is a human body.

In the conventional infrared detection apparatus, it is a figure which shows the graph explaining the output characteristic when an infrared sensor detects a detection target. It is a schematic block diagram for demonstrating the infrared rays detection apparatus which concerns on this invention. It is a schematic explanatory drawing which shows the relationship between the detection range of each of the 1st, 2nd infrared sensor, and a detection target object in the example where the infrared detection apparatus which concerns on this invention was applied to the notebook type personal computer. It is a block diagram of the signal processing part in the infrared detection apparatus which concerns on this invention. It is an actual arrangement drawing of an infrared sensor in an infrared detection device concerning the present invention. In the infrared detection device according to the present invention, it is a main part enlarged view showing in detail the positional relationship between the infrared detection region and the detection angle limiter. It is a figure which shows the output change of a 1st, 2nd infrared sensor on a graph with respect to the presence or absence of the human body which is a detection target in the example in which the infrared rays detection apparatus which concerns on this invention was applied to the notebook computer. In an example in which the infrared detection device according to the present invention is applied to a notebook computer, the value obtained by subtracting the output of the first infrared sensor from the output of the second infrared sensor with respect to the presence or absence of a human body as a detection target FIG. In an example in which the infrared detection device according to the present invention is applied to a notebook computer, a value obtained by dividing the output of the second infrared sensor by the output of the first infrared sensor with respect to the presence or absence of a human body as a detection target FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Infrared detector]
FIG. 2 is a schematic configuration diagram for explaining an infrared detection device according to the present invention. As illustrated in FIG. 2, the infrared detection device 200 is an infrared detection device that detects infrared rays emitted from a detection target (for example, a human body), and includes an infrared detection unit 100 and a signal processing unit 10. The infrared detector 100 outputs a signal corresponding to the amount of incident infrared rays. The signal processing unit 10 processes the signal detected by the infrared detection unit 100. The infrared detector 100 is capable of detecting the absolute value of the amount of incident infrared rays, the first infrared sensor 1 and the second infrared sensor 2 (hereinafter, a plurality of infrared sensors 1 and 2 or simply infrared rays. Sensors 1 and 2). The detection ranges A and B corresponding to the infrared sensors 1 and 2 are ranges in which the outputs of the infrared sensors 1 and 2 change when an object having a temperature different from that of the infrared sensors 1 and 2 exists.

The two infrared sensors 1 and 2 specify any two of the plurality of infrared sensors included in the infrared detection unit 100. Therefore, the number of infrared sensors provided in the infrared detecting unit 100 is not limited and may be three or more. At least the infrared sensors 1 and 2 are disposed on the same plane.
As shown in FIG. 2, the infrared detection unit 100 includes at least two infrared sensors 1 and 2 that can detect the absolute value of the amount of incident infrared rays. The detection ranges A and B of these two infrared sensors 1 and 2 are set so as to satisfy the following conditions. The condition is that the virtual projection planes 11 and 12 are projected on the virtual plane 13 facing the infrared detection unit 100 as the detection ranges A and B, and the projection planes 11 and 12 are bordered. This is a condition that the virtual outer circumferential lines 4 and 5 do not match. That is, the detection ranges A and B of the two infrared sensors 1 and 2 are set based on the condition that they are not at least completely coincident.

When one detection target exists in the detectable range, the ratio of the detection target in the output signal of the first infrared sensor 1 related to the detection range A and the output of the second infrared sensor 2 related to the detection range B The detection angle limiter 20 appropriately limits the detection ranges A and B of the infrared sensors 1 and 2 so that the ratio of the detection object in the signal is different.
As shown in FIG. 2, the two infrared sensors 1 and 2 included in the infrared detection unit 100 have a maximum detection angle that spreads forward from the light receiving surface 3. This maximum detection angle is a concept that can be said to be a visual field if the infrared sensors 1 and 2 are replaced with human eyes. The infrared detection unit 100 narrows the maximum detection angle similar to this field of view by the detection angle limiter 20 in the vicinity of the light receiving surface 3. That is, the infrared detection unit 100 includes a detection angle limiter 20 that limits the detection ranges A and B of the two infrared sensors 1 and 2. The detection angle limiter 20 includes an infrared light shielding part 23 having a light shielding property and an infrared transmitting part 24 having a light transmitting property. The detection angle limiter 20 includes an infrared transmission part 24 formed in one window shape and an infrared light shielding part 23 surrounding the infrared transmission part 24 in a window frame shape.

The detection range A indicates the detection range of the first infrared sensor 1, and the detection range B indicates the detection range of the second infrared sensor 2. The detection angle limiter 20 is configured in the infrared detection device 200 itself, or the detection angle limiter 20 is configured by providing a window in a housing of an electronic device on which the infrared detection device 200 is mounted. Either configuration may be used.
Further, in order to set the detection ranges A and B of the first and second infrared sensors 1 and 2 to a desired setting, at least one of the detection angle limiter 20 and a lens (not shown) is used. You may do it.

  Of course, the infrared light transmittance of the infrared light shielding portion 23 is necessarily lower than the infrared transmittance of the infrared light transmitting portion 24, preferably 10% or less, and more preferably 5% or less. . In addition, the infrared transmittance of the infrared transmitting portion 24 is naturally required to be higher than that of the infrared light shielding portion 23, preferably 20% or more, and more preferably 50% or more.

  For this reason, a metal, plastic, epoxy resin, liquid crystal polymer (LCP), polyphenylene sulfide (PPS) resin, or the like, which has been surface-treated so as not to reflect infrared rays, is used as a member constituting the infrared light shielding unit 23. Further, high density polyethylene, GORE-TEX (registered trademark), Si, Ge, sapphire glass, or the like is used as a member constituting the infrared transmitting portion 24. The infrared transmitting portion 24 can be realized by simply providing a hole such as a pin hole on the plate surface forming the detection angle limiting body 20. Further, a circle, an ellipse, a square, a rectangle, a polygon, or the like can be adopted as the shape of the infrared transmitting portion 24. In addition, it is preferable from the point which simplifies a manufacturing process that the infrared rays transmission part 24 is one.

  Due to the synergistic action of the detection angle restricting body 20 and the two infrared sensors 1 and 2, it is possible to confirm the presence or absence of the detection target in the detection ranges A and B of the infrared detection device 200. Further, in the infrared detection apparatus 200, the signal processing unit 10 determines whether or not a detection target exists in a detection region including the detection ranges A and B. The signal processing unit 10 determines the presence / absence of a detection target based on a difference in output between the two infrared sensors 1 and 2 or an output ratio. That is, as a result of comparing the outputs of the detection signals of the two infrared sensors 1 and 2, if the proportion of infrared rays detected from the detection target is different, the detection target is included in the detection region including the detection ranges A and B. A determination result that an object exists is obtained.

That is, the signal processing unit 10 determines that the detection target exists in the detectable range by detecting that the occupation ratios of the detection target in the detection ranges A and B are different.
In addition, the ratio of the detection object occupying the detection ranges of the two infrared sensors 1 and 2 is different when the detection ranges of the two infrared sensors 1 and 2 are projected onto a plane including the detection object. In each projection view that can be made, the ratio of the area including the detection target object to the area not including the detection target object is different.

Here, by using the ratio of the outputs of the two infrared sensors 1 and 2, even if the two infrared sensors 1 and 2 have a predetermined temperature characteristic, the temperature characteristic can be canceled. It becomes possible to detect the detection object stably over a wide temperature range.
Note that the plurality of infrared sensors including the two infrared sensors 1 and 2 are formed on the same substrate 19, and the influence of the relative positional deviation with respect to the detection angle limiter 20 and the plurality of infrared sensors 1. , The influence of output deviation due to the temperature difference between the two is alleviated.

  In addition, when a plurality of infrared sensors are formed of a semiconductor thin film formed by vapor deposition or the like, it is known that the infrared sensors on the wafer have closer electrical characteristics as they are closer to each other. Accordingly, the two infrared sensors 1 and 2 configured on the same substrate 19 have substantially the same electrical characteristics and temperature characteristics. As described above, when the characteristics of the two infrared sensors 1 and 2 used in the infrared detecting device 200 are the same, later calculation and adjustment at the time of shipment become easier.

  FIG. 3 shows an example in which the infrared detection apparatus according to the present invention is applied to a notebook personal computer (hereinafter referred to as a notebook personal computer or simply a personal computer), and the detection ranges and detection objects of the first and second infrared sensors. It is a schematic explanatory drawing which shows these relationships. As shown in FIG. 3, in the infrared detection device 200 of the personal computer 90 provided with the infrared detection device 200, the detection target 6 is a human body. The personal computer 90 includes a display 80. The display 80 includes an image display unit 83 and a frame unit 81 that surrounds the image display unit 83, and the infrared detection device 200 is mounted on the frame unit 81. In the display 80, a straight line C connecting the two infrared sensors 1 and 2 that are components of the infrared detection device 200 is arranged so as to be parallel to the frame portion 81.

  That is, in the display 80 and the notebook computer 90, it means that the two infrared sensors 1 and 2 provided in the infrared detecting device 200 are arranged at predetermined intervals in the vertical and horizontal directions of the device. In particular, an arrangement in which the straight line C is parallel to the vertical frame portion 82 of the display 80 is preferable. This is because, in a device such as the display 80 or a notebook computer 90 including the display 80, the two infrared sensors 1 and 2 included in the infrared detecting device 200 are arranged at predetermined intervals in the vertical direction of the device. Means that.

  As shown in FIG. 3, in a notebook computer 90, a base 91 equipped with a keyboard or the like is used by being placed horizontally on a desk. The display 80 is used in an opened state at an opening angle R with respect to the base 91. At this time, the ratio of the detection range A of the first infrared sensor 1 to the arm, chest, and abdomen of the human body 6 in the detection range B of the second infrared sensor 2 is higher than the ratio of the head of the human body 6 to the detection range A. Is bigger. In such a state, when the background temperature is lower than that of the human body 6, the output of the second infrared sensor 2 is larger than the output of the first infrared sensor 1. Therefore, the presence or absence of the human body 6 in the detection ranges A and B can be detected based on the output difference or the output ratio between the first and second infrared sensors 1 and 2. In order to obtain these output differences or output ratios, neither detection time nor processing time is required. Therefore, the presence or absence of the human body 6 in the detection ranges A and B can be detected immediately after the infrared detection device 200 is activated.

  As an application example of the infrared detection device 200, the notebook computer 90 is illustrated in FIG. 3, but as another example, a display for a desktop personal computer (not shown) or an external display (not shown) connected to the laptop personal computer 90, A display of a tablet-type information terminal (not shown) can be used. Needless to say, application examples of the infrared detection device 200 are not limited to these examples.

  Note that the detection ranges A and B of the infrared detection device 200 here are, for example, in the case of the infrared detection device 200 mounted on the notebook computer 90 or the display 80, the person using the notebook computer 90 or the display 80. Is a range in which can exist. When using these devices, the linear distance from the infrared detection device 200 to the human body 6 is generally within 1 m. Needless to say, the detection ranges A and B are not limited to approximately 1 m as described above because they differ depending on the type of equipment used.

In the example shown in FIG. 3, the first and second infrared sensors 1 and 2 are arranged such that the distances J and K in the vertical direction with respect to the ground G are different, and the detection range is detected by the detection angle limiter 20. Although A and B are shifted in the vertical direction with respect to the ground G, they are not limited to the vertical direction. That is, depending on the detection range required for the infrared detection device 200, the first and second infrared sensors 1, 2 are arranged in a horizontal direction with respect to the ground G at a predetermined interval, and the detection angle limiter 20 The detection ranges A and B of the first and second infrared sensors 1 and 2 may be shifted in the horizontal direction with respect to the ground G.
On the other hand, when the desired detection range is multi-directional or wide, etc., four infrared sensors are used to move the first and second infrared sensors 1 and 2 to the distances J and K perpendicular to the ground G. The third and fourth infrared sensors (not shown) may be arranged with a predetermined interval in the horizontal direction with respect to the ground G.

[Infrared sensor]
The first and second infrared sensors 1 and 2 of the present embodiment are preferably quantum infrared sensors capable of integrating a plurality of sensors in a small area. In addition, a quantum type infrared sensor in which a photodiode using InSb such as IR1011 manufactured by Asahi Kasei Electronics is configured on a GaAs substrate is also suitable.

  In addition, a thermopile or the like that is an absolute infrared ray amount sensor can detect an absolute amount, not a change amount of incident infrared rays, similarly to the quantum infrared sensor. However, since the thermopile is a sensor using the Seebeck effect, it is difficult to obtain a sufficient output. That is, in order for the thermopile to obtain sufficient output, a predetermined distance is required to ensure a large temperature difference between the hot spot and the cold spot (reference point). Therefore, a sufficient output cannot be obtained if a plurality of sensors are densely arranged in a small area. On the other hand, in order to obtain a necessary signal, the size of the corresponding portion is increased, which is not suitable for applications that require miniaturization. That is, the size of the notebook personal computer 90 or the display 80 is difficult to equip. Therefore, it is desirable that the infrared sensors 1 and 2 used in the infrared detecting device 200 are quantum infrared sensors.

[Signal processing section]
FIG. 4 is a block diagram of a signal processing unit in the infrared detection apparatus according to the present invention. As shown in FIG. 4, the signal processing unit 10 includes an amplification circuit unit 7 that amplifies outputs of a plurality of infrared sensors including at least the infrared sensors 1 and 2, and a calculation unit that calculates signals amplified by the amplification circuit unit 7. 8 and a determination unit 9 that determines the presence or absence of the human body 6 from the comparison result between the calculation result of the calculation unit 8 and the threshold value set by the threshold value setting unit 15. Based on the determination output of the determination unit 9, power supply control for turning off the lighting of the room where no one is present is performed. The arithmetic unit 8 in the signal processing unit 10 may have a configuration including an AD converter (not shown). In addition, the calculation unit 8 and the determination unit 9 are not necessarily provided in the infrared detection device 200, and are provided on the side of an electronic device such as the notebook computer 90 or the display 80 on which the infrared detection device 200 is mounted. It may be a configuration.

Hereinafter, the infrared detection apparatus 200 will be described more specifically and in detail. However, the present invention is not limited to these.
FIG. 5 is an actual layout diagram of the infrared sensor in the infrared detecting device according to the present invention. The two infrared sensors 1 and 2 shown in FIG. 5 are preferably quantum infrared sensors. The first and second infrared sensors 1 and 2 are preferably disposed on the same substrate 19. However, it may be configured by another arrangement method that does not use the same substrate 19. The infrared sensors 1 and 2 are arranged with a predetermined separation distance d so that the vertical distances J and K to the ground G or the horizontal reference plane H are different.

  As shown in FIG. 5, the infrared sensors 1 and 2 are formed on the same GaAs substrate 19. The width W of each of the first and second infrared sensors 1 and 2 is 160 μm, and the length L of each of the infrared sensors 1 and 2 is 100 μm. The first infrared sensor 1 and the second infrared sensor 2 are arranged on the substrate 19 with a distance d = 265 μm between the centers. These infrared sensors 1 and 2 are quantum type infrared sensors using an InSb diode as described in Patent Document 2.

  FIG. 6 is an enlarged view of a main part showing in detail the positional relationship between the infrared detection region and the detection angle limiter in the infrared detection device according to the present invention. As shown in FIG. 6, the distance a from the infrared sensors 1 and 2 to the detection angle restricting body 20 is 0.4 mm, the thickness t of the detection angle restricting body 20 is 0.5 mm, and the infrared transmitting portion 24 is added to the detection angle restricting body 20. The diameter of the hole provided as Φ = 1.0 mm. Polyphenylene sulfide (PPS) resin is used as the material of the detection angle limiter 20.

  FIG. 7 is a graph showing changes in the outputs of the first and second infrared sensors with respect to the presence / absence of a human body as a detection target in an example in which the infrared detection device according to the present invention is applied to a notebook computer. is there. As shown in FIG. 7, when the human body 6 (FIG. 3) is in the detection ranges A and B of the infrared detection device 200, the human body 6 is seated at a linear distance of 50 cm from the infrared detection device so as to face the infrared detection device. doing. The outputs of the first and second infrared sensors 1 and 2 shown in FIG. 7 are measured values when the notebook computer 90 shown in FIG. 3 is set to the opening angle R = 110 °. At this time, the outputs of the infrared sensors 1 and 2 are I / V converted by a resistance of 1 MΩ and then amplified 240 times. From these results, when the human body 6 is in the detection ranges A and B of the infrared detection device 200, the output of the first infrared sensor 1 and the output of the second infrared sensor 2 show different values. On the other hand, when the human body 6 is not in the detection ranges A and B of the infrared detection device 200, the output value of the first infrared sensor 1 and the output value of the second infrared sensor 2 indicate similar values. I understand.

  FIG. 8 shows an example in which the infrared detection apparatus according to the present invention is applied to a notebook computer, and the output of the first infrared sensor is subtracted from the output of the second infrared sensor with respect to the presence or absence of the human body that is the detection target. FIG. From the result shown in FIG. 8, it can be seen that the presence or absence of the human body 6 in the detection ranges A and B of the infrared detection device 200 can be determined using the difference between the outputs of the first and second infrared sensors 1 and 2. .

  FIG. 9 shows an example in which the infrared detection apparatus according to the present invention is applied to a notebook computer, and the output of the second infrared sensor is divided by the output of the first infrared sensor with respect to the presence or absence of a human body as a detection target. It is a figure which shows the measured value on a graph. From the results shown in FIG. 9, it can be seen that the presence or absence of the human body 6 in the detection ranges A and B of the infrared detection device 200 can be determined using the ratio of the outputs of the first and second infrared sensors 1 and 2. .

  From the above results, according to the infrared detection device of the present embodiment, it is possible to realize an infrared detection device capable of determining the presence or absence of a detection target in the detection range immediately after the infrared detection device is activated. The detection target is not limited to a person, and the present invention can be applied to any object that emits a certain amount of heat, that is, infrared rays, such as animals and automobiles.

  In addition to the power-saving device that eliminates the waste of leaving the lights, air conditioners, and TVs in rooms where no one is on in the on state, unauthorized operation of third parties or unauthorized viewing of information on personal computers left by users Computer security devices that prevent theft, as well as equipment that requires body temperature and heat generation, such as animals and automobiles, that is, those that emit infrared rays, to detect the presence or absence of the detection object, industrially There is a possibility of use.

DESCRIPTION OF SYMBOLS 1 1st infrared sensor 2 2nd infrared sensor 3 Light-receiving surface 4, 5 Perimeter line 6 Detection target (human body)
7 Amplifying circuit unit 8 Calculation unit 9 Determination unit 10 Signal processing unit 11, 12 Projection surface 13 Virtual plane 19 Substrate 15 Threshold setting unit 20 Detection angle limiter 23 Infrared light shielding unit 24 Infrared transmission unit 80 Display 81 Frame unit 82 Vertical frame Unit 83 image display unit 90 (note type) personal computer 91 base unit 100 infrared sensor 200 infrared detection device

Claims (14)

In an infrared detection device that detects the presence or absence of a detection target based on a signal detected by an infrared detection unit that outputs a signal according to the amount of incident infrared rays,
The infrared detection unit has a plurality of infrared sensors capable of detecting an absolute value of an incident infrared amount,
Each detection range set in the infrared sensor is such that a virtual outer peripheral line bordering each virtual projection plane projected as the detection range does not coincide with a virtual plane facing the infrared detection unit. An infrared detector characterized by satisfying The infrared detection unit includes a detection angle limiter that limits each detection range of the infrared sensor by narrowing a detection angle extending forward from the light receiving surface of the infrared sensor in the vicinity of the light receiving surface,
The infrared detection device according to claim 1, wherein the detection angle limiter includes an infrared light shielding unit having a light shielding property and an infrared transmitting unit having a light transmitting property.   3. The infrared ray according to claim 2, wherein the detection angle restricting body includes an infrared ray transmitting portion formed in a single window shape and an infrared ray shielding portion surrounding the infrared ray transmitting portion in a window frame shape. Detection device.   The signal processing unit can determine whether or not there is a detection target in a detection region including each detection range, and as a result of comparing the output of each detection signal of the infrared sensor, The determination result that the detection target exists in the detection region including each of the detection ranges is obtained when the ratio of infrared rays detected from the detection target is different. An infrared detection apparatus according to 1.   The infrared detection device according to claim 4, wherein the signal processing unit determines the presence or absence of a detection target based on a difference in output of the infrared sensors or a ratio of the outputs.   The infrared detection device according to claim 1, wherein the infrared sensors are arranged with a predetermined separation distance so that vertical distances to the horizontal reference plane are different from each other.   The infrared detection device according to claim 1, wherein the infrared sensors are arranged at a predetermined separation distance in a direction parallel to the ground surface or the floor surface.   The infrared detection apparatus according to claim 1, wherein the detection target is a human body that emits infrared rays.   The infrared detection device according to claim 1, wherein the infrared sensor is formed on the same substrate.   The infrared detection apparatus according to claim 1, wherein the infrared sensor is a quantum infrared sensor.   A display comprising the infrared detection device according to claim 1, wherein the straight line connecting the infrared sensors is connected to the frame portion. A display, wherein the infrared detection device is arranged in the frame portion so as to be parallel.   The display according to claim 11, wherein a straight line connecting the infrared sensors is parallel to a vertical frame portion of the display.   A personal computer comprising the infrared detection device according to claim 1.   A personal computer comprising the display according to claim 11 or 12.

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