JP6042137B2 - Infrared sensor module - Google Patents

Description

  The present invention relates to an infrared sensor module for performing infrared detection.

  FIG. 1 shows a configuration of a conventional infrared sensor module. As shown in FIG. 1, a conventional infrared sensor module 100 includes an infrared sensor 101, an optical filter 102 provided on the infrared sensor 101, and a molding member 103 for molding the infrared sensor 101 and the optical filter 102. And a viewing angle limiter 104 having a window 105 for limiting the field of view of the light receiving unit of the infrared sensor 101.

  When an infrared ray radiated from an object is incident on the infrared sensor module 100, the incident angle is limited by the window 105 of the viewing angle restricting body 104 and is incident on the optical filter 102, and a specific wavelength is blocked by the optical filter 102. Is incident on the infrared sensor 101. The infrared sensor module 100 determines whether or not an object has entered the field of view by detecting the incident light in this way. As the optical filter 102, for example, an optical member that selectively transmits long-wavelength infrared light can be used (see Patent Document 1).

JP 10-187116 A

  In order to perform proximity sensing, gesture detection, living body detection, and the like in an electronic device such as a mobile phone, it is conceivable to use image processing by a camera, for example. Because of high power consumption, it has been difficult to apply to actual electronic devices such as mobile phones.

  On the other hand, since the infrared sensor module 100 as shown in FIG. 1 has low power consumption, proximity detection, gesture detection, living body detection, and the like in an electronic device such as a mobile phone are performed using the infrared sensor module 100. If possible, it is possible to realize low power consumption for detection as described above.

  However, when the infrared sensor module 100 is applied to an electronic device such as a mobile phone, it is necessary to cover the visual field of the infrared sensor module 100 with a transparent member made of aluminosilicate glass or the like. When covering the visual field of the infrared sensor module 100 with a transparent member, in addition to blocking the light of the short wavelength side by the optical filter 102, the transparent member blocks the light of the long wavelength side. There was a problem that it was not possible to obtain the required sensitivity. Further, when the optical filter 102 is not mounted, there is a problem that it is difficult to detect with high accuracy due to disturbance factors such as sunlight.

  The present invention has been made in view of the above problems, and its purpose is to determine whether an object has entered the field of view even when the field of view of the infrared sensor module is covered with a transparent member. It is to provide an infrared sensor module capable of performing the above with high accuracy.

An infrared sensor module according to an aspect of the present invention includes an infrared sensor including an optical member that transmits only light having a wavelength of 4.2 μm to 4.35 μm, and a transparent member that covers a field of view of the infrared sensor. And

The infrared sensor module which concerns on the other aspect of this invention is said infrared sensor module, Comprising: The said transparent member contains the material which consists of aluminosilicate glass, It is characterized by the above-mentioned.

An infrared sensor module according to another aspect of the present invention is the infrared sensor module described above , wherein the infrared sensor is a quantum infrared sensor.

The electronic device which concerns on the other aspect of this invention is equipped with said infrared sensor module, It is characterized by the above-mentioned .

An infrared sensor for biological detection according to another aspect of the present invention includes an optical member that transmits only light having a wavelength of 4.2 μm to 4.35 μm.

  According to the present invention, since an infrared sensor is used, it is possible to determine whether or not an object has entered the field of view with low power consumption, and even when the field of view of the infrared sensor is covered with a transparent member, An infrared sensor module capable of performing the above determination and the like with high accuracy can be provided.

It is a figure which shows the structure of the conventional infrared sensor module. It is a figure which shows the structure of the infrared sensor module which concerns on the reference example 1. FIG. It is a figure which shows the structure of the infrared sensor module which concerns on the reference example 2. FIG. It is a figure which shows the structure of the infrared sensor module which concerns on the Example of this invention. It is a figure which shows an infrared sensor output when an object enters into the visual field of an infrared sensor module. It is a figure for demonstrating the optical characteristic with respect to the infrared rays of the optical filter used in FIG.

(Reference Example 1)
FIG. 2 shows a configuration of an infrared sensor module according to Reference Example 1. As illustrated in FIG. 2, the infrared sensor module 200 according to the reference example 1 includes an infrared sensor 201, a molding member 203 for molding the infrared sensor 201, and a field of view of a light receiving unit of the infrared sensor 201. A viewing angle limiting body 204 having a window 205 and a transparent member 206 provided on the viewing angle limiting body 204 so as to cover the field of view of the infrared sensor module 200 are provided. As the transparent member 206, a glass material including aluminosilicate glass or the like can be used. A transparent member containing aluminosilicate glass or the like has a characteristic of blocking infrared rays having a wavelength of 5 μm or more.

  In the infrared sensor module 200 according to Reference Example 1, light having a wavelength of 5 μm or more is blocked by the transparent member 206, and light having a wavelength of 5 μm or less transmitted without being blocked by the transparent member 206 is incident on the infrared sensor 201. Infrared detection is performed. As described above, in the infrared sensor module 200, infrared detection is performed by light having a wavelength of 5 μm or less that is transmitted without being blocked by the transparent member 206. From the viewpoint of sensitivity, an object can be viewed in an electronic device such as a mobile phone. It is possible to determine whether or not it has entered.

  However, since the light in the wavelength band of 5 μm or less incident on the infrared sensor 201 in this way includes disturbance factors that vary depending on the measurement environment due to sunlight or the like, in the infrared sensor module 200 according to Reference Example 1, There was a problem that high-precision detection was difficult.

(Reference Example 2)
FIG. 3 shows a configuration of an infrared sensor module according to Reference Example 2. As shown in FIG. 3, an infrared sensor module 300 according to Reference Example 2 includes an infrared sensor 301, an optical filter 302 provided on the infrared sensor 301 and blocking light having a wavelength of 5 μm or less, and the infrared sensor 301. And a molding member 303 for molding the optical filter 302, a viewing angle limiter 304 having a window 305 for limiting the field of view of the light receiving unit of the infrared sensor 301, and a viewing angle so as to cover the field of view of the infrared sensor module 300. And a transparent member 306 provided on the restriction body 304.

  In the infrared sensor module 300 according to Reference Example 2, a wavelength of 5 μm or less is blocked by the optical filter 302, and light having a wavelength of 5 μm or more is blocked by the transparent member 306. Therefore, since no infrared rays of any wavelength are incident on the infrared sensor, it is impossible to determine whether an object has entered the field of view.

(Example)
FIG. 4 shows the configuration of an infrared sensor module according to the present invention. As shown in FIG. 4, an infrared sensor module 400 according to the present invention includes an infrared sensor 401 and an optical filter 402 provided on the infrared sensor 401 that transmits only light having a wavelength of 4.2 μm to 4.35 μm. A molding member 403 for molding the infrared sensor 401 and the optical filter 402, a viewing angle limiter 404 having a window 305 for limiting the field of the light receiving unit of the infrared sensor 401, and the field of view of the infrared sensor module 400. And a transparent member 406 provided on the viewing angle limiter 404 so as to cover it. As the transparent member 406, a glass material such as aluminosilicate glass can be used as described above. Infrared sensor 401 can preferably be a quantum infrared sensor. The “optical filter that transmits only light having a wavelength of 4.2 μm to 4.35 μm” means that the transmittance of infrared light having a wavelength shorter than 4.2 μm and longer than 4.35 μm is 30%, preferably 20% or less. More preferably, it means an optical member that is 10% or less.

  In the infrared sensor module 400 according to the embodiment, infrared detection is performed using light having a wavelength of 4.2 μm to 4.35 μm. From the viewpoint of sensitivity, whether or not an object has entered the field of view in an electronic device such as a mobile phone. Judgment and the like can be performed. Furthermore, since the light having a wavelength of 4.2 μm to 4.35 μm has very few disturbance factors caused by sunlight and varies depending on the measurement environment, highly accurate detection is possible.

  FIG. 5 exemplifies an infrared sensor output change when a hand (surface temperature around 34 degrees) is held over the visual field of the infrared sensor module at an environmental temperature of 28 degrees. FIG. 5A illustrates the sensor output change of the infrared sensor module 200 according to Reference Example 1 in which no optical filter is mounted, and FIG. 5B uses an optical filter 302 that blocks light with a wavelength of 5 μm or less. The sensor output change of the infrared sensor module 300 according to the reference example 2 is illustrated, and FIG. 5C relates to the embodiment using the optical filter 402 that transmits only light having a wavelength of 4.2 μm to 4.35 μm. The sensor output change of the infrared sensor module 400 is illustrated.

  5B, a 5 μm cut long pass filter manufactured by Nippon Vacuum Optics Co., Ltd. is used as the optical filter 302. In FIG. 5C, a 4.2 μm band pass filter manufactured by Nippon Vacuum Optics Co., Ltd. is used as the optical filter 402. It was used.

  Here, the optical characteristics of the 5 μm cut long pass filter and the 4.2 μm band pass filter used in FIG. 5 with respect to infrared rays will be described with reference to FIG. FIG. 6A shows the optical characteristics of the 5 μm cut long-pass filter with respect to infrared light, and FIG. 6B shows the optical characteristics of the 4.2 μm band-pass filter with respect to infrared light. As shown in FIG. 6 (a), it is understood that in the 5 μm cut long pass filter, the transmittance of infrared rays suddenly decreases from a wavelength shorter than 5 μm. As shown in FIG. 6B, it is understood that the transmittance of infrared light having a wavelength shorter than 4.2 μm and longer than 4.35 μm is 10% or less in the 4.2 μm bandpass filter. .

In any of the examples shown in FIG. 5, the infrared sensor includes an InSb layer formed by MBE on a semi-insulating GaAs single crystal substrate and doped with 1.0 × 10 ¹⁹ atoms / cm ^{3 of} Sn. (N-type semiconductor layer, 1.0 μm), InSb layer doped with Zn at 1 × 10 ¹⁶ atoms / cm ³ (intrinsic semiconductor layer, 2.0 μm), Al _0.2 In doped with Zn at 5 × 10 ¹⁸ atoms / cm ³ An infrared sensor having a semiconductor stack composed of a _0.8 Sb layer (barrier layer, 0.02 μm) and InSb (p-type semiconductor layer, 0.5 μm) doped with 5 × 10 ¹⁸ atoms / cm ^{3 of} Zn was used. In each of the examples shown in FIG. 5, the viewing angle limiter is made of polyphenylene sulfide (PPS) resin, and the window has a cylindrical shape with a diameter of 1.05 mm and a height of 0.50 mm.

  As shown in FIG. 5A, in the case of the infrared sensor module 200 not equipped with an optical filter, the output is lowered even though a hand having a temperature higher than the environmental temperature has entered the field of view. Is understood. This is presumably because the output was reduced by the hand blocking the infrared rays, which are disturbance factors caused by sunlight and the like. This makes it impossible to determine when the object has entered the field of view, and it is understood that this is not suitable for object detection.

  Further, as shown in FIG. 5B, in the case of the infrared sensor module 300 using an optical filter that blocks light having a wavelength of 5 μm or less, the output does not vary depending on whether an object enters the field of view. It is understood that the object cannot be detected.

  On the other hand, as shown in FIG. 5C, in the case of the infrared sensor module 400 according to the present invention using an optical filter that transmits only light having a wavelength of 4.2 μm to 4.35 μm, the ambient temperature It is understood that the output is increased due to the fact that the hands with high temperature entered the field of view. Therefore, it is understood that the infrared sensor module 400 according to the embodiment of the present invention can correctly determine whether or not an object has entered the field of view from the relationship between the environmental temperature and the temperature of the object.

  As described above, in the infrared sensor module 400 according to the present invention, by using the optical filter 402 that transmits only light having a wavelength of 4.2 μm to 4.35 μm, as shown in FIG. It can be determined with high accuracy whether or not it has entered.

  Since the infrared sensor module according to the present invention can determine with high accuracy whether or not an object has entered the field of view, it is suitable to be applied to an electronic device that performs proximity detection, gesture detection, living body detection, and the like. is there.

100, 200, 300 Infrared sensor module 101, 201, 301, 401 Infrared sensor 102, 302, 402 Optical filter 103, 203, 303 Molding member 104, 204, 304, 404 Viewing angle limiter 105, 205, 305, 405 Window 206, 306, 406 Transparent member

Claims (2)

An electrical device that performs living body detection by detecting infrared radiation radiated from a living body to be detected,
An infrared sensor including an optical member that transmits only light having a wavelength of 4.2 μm to 4.35 μm;
A molding member for molding the infrared sensor;
A viewing angle limiter having a window for limiting the field of view of the infrared sensor;
A transparent member that is provided on the viewing angle limiter and includes a material made of aluminosilicate glass and covers the field of view of the infrared sensor;
An electric device comprising an infrared sensor module having The electrical apparatus according to claim 1, wherein the infrared sensor is a quantum infrared sensor.

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