Shielding assembly and electronic device having infrared sensing function

Abstract

A shielding device for fixing a passive infrared sensor to a circuit board includes: a first shielding base fixed to the circuit board; a second shielding base fixed inside the first shielding base and pressing against the circuit board, the passive infrared sensor passing through the first and second shielding bases and fixed to the circuit board; and a metal shielding cover with a central opening to expose the probe of the passive infrared sensor, the metal shielding cover being sealed and assembled with the first shielding base. This invention utilizes a non-metallic shielding base and air as a heat insulation medium to reduce heat conduction and improve the sensing stability of the infrared sensor. The sealed assembly of the metal shielding cover and the first shielding base effectively shields against radiation interference, improving the anti-interference capability of the passive infrared sensor. This invention also provides an electronic device with infrared sensing functionality.

Claims

1. A shielding device for fixing a passive infrared sensor to a circuit board, wherein, The shielding device includes: a first shielding base, which is a metal annular shielding base, fixed to the circuit board; a second shielding base, which is a non-metallic annular shielding base, fixed to the inner side of the first shielding base and pressing against the circuit board, wherein the passive infrared sensor passes through the first shielding base and the second shielding base and is fixed to the circuit board; and a metal shielding cover with a central opening to expose the probe of the passive infrared sensor, wherein the metal shielding cover is sealed and assembled with the first shielding base.

2. The shielding device as described in claim 1, wherein, The second shielding base includes: an outer ring structure, fixed to the inner side of the first shielding base and pressing against the circuit board; and an inner ring structure, the outer surface of the inner ring structure being connected to the inner surface of the outer ring structure and forming a stepped structure, the passive infrared sensor being supported and fixed by the stepped structure, and a hollow area being formed between the passive infrared sensor and the circuit board.

3. The shielding device as described in claim 2, wherein: The first shielding seat has at least one positioning groove on its inner side; the outer ring structure of the second shielding seat has at least one positioning protrusion that matches the at least one positioning groove on its outer side, and the second shielding seat is fixed to the inner side of the first shielding seat by the positioning protrusion and the at least one positioning groove.

4. The shielding device as described in claim 2, wherein, The outer ring structure is also provided with a positioning notch for positioning the installation direction of the passive infrared sensor.

5. The shielding device as claimed in claim 1, wherein, The first shielding base is sealed and fixed to the circuit board using surface mount technology.

6. The shielding device as claimed in claim 1, wherein, The opening diameter of the metal shielding cover is larger than the diameter of the probe of the passive infrared sensor but smaller than the maximum diameter of the passive infrared sensor.

7. An electronic device with infrared sensing function, comprising: Circuit board; Passive infrared sensor, used to detect infrared radiation; A shielding device is used to fix the infrared sensor onto the circuit board. The shielding device includes: a first shielding base, which is a metal ring shielding base, fixed onto the circuit board; The second shielding base is a non-metallic annular shielding base, fixed inside the first shielding base and pressing against the circuit board. The passive infrared sensor passes through the first shielding base and the second shielding base and is fixed on the circuit board. The metal shielding cover has an opening in the middle to expose the probe of the passive infrared sensor. The metal shielding cover is sealed and assembled with the first shielding base.

8. An electronic device with infrared sensing function as described in claim 7, wherein, The second shielding base includes: an outer ring structure, fixed to the inner side of the first shielding base and pressing against the circuit board, the outer ring structure having a positioning notch for positioning the installation direction of the passive infrared sensor; and an inner ring structure, the outer surface of the inner ring structure being connected to the inner surface of the outer ring structure and forming a stepped structure, the stepped structure being used to support and fix the passive infrared sensor and to create a hollow area between the passive infrared sensor and the circuit board.

9. An electronic device with infrared sensing function as described in claim 8, wherein, The first shielding seat has at least one positioning groove on its inner side; the outer ring structure of the second shielding seat has at least one positioning protrusion that matches the at least one positioning groove on its outer side, and the second shielding seat is fixed to the inner side of the first shielding seat by the positioning protrusion and the at least one positioning groove.

10. An electronic device with infrared sensing function as described in claim 7, wherein, The opening diameter of the metal shielding cover is larger than the diameter of the probe of the passive infrared sensor but smaller than the maximum diameter of the passive infrared sensor.

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