Pipe cap for pyroelectric infrared sensor and pyroelectric infrared sensor

Abstract

The utility model belongs to the technical field of infrared sensors, and particularly relates to a pipe cap for a pyroelectric infrared sensor and the pyroelectric infrared sensor. The pipe cap for the pyroelectric infrared sensor comprises a pipe cap body, the pipe cap body is provided with an internal space for accommodating an infrared sensitive element of the pyroelectric infrared sensor, the side wall of the pipe cap body comprises at least one cambered surface section and at least one straight surface section, and the cambered surface section is used for positioning a circular lens of the pyroelectric infrared sensor. The pipe cap body is installed on the base plate, after the circular lens is arranged on the top of the pipe cap body and coaxially arranged with the cambered surface section, the orthographic projection of the circular lens on the base plate is a circular ring, the pipe cap body is located in the circular ring, and the first element close to the straight surface section is also located in the circular ring. Therefore, a part of space can be reserved in the pipe cap body for installing the first element, the size of the pyroelectric infrared sensor is reduced, the compactness of the pyroelectric infrared sensor is improved, and the miniaturization design of the pyroelectric infrared sensor is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of infrared sensors, in particular to a tube cap for a pyroelectric infrared sensor and the pyroelectric infrared sensor. Background Art

[0002] Pyroelectric infrared sensor is a sensor that detects infrared thermal radiation using materials with good pyroelectric properties as the core. It is mainly used to detect infrared rays from people, animals, and other objects with thermal radiation to determine whether there are people or other animals in a certain space. It is widely used in inductive lighting, intrusion alarm, security, smart home and other fields.

[0003] In the prior art, the packaging types of pyroelectric infrared sensors are mainly direct-insert type and surface-mount type. The direct-insert type pyroelectric infrared sensor mainly has a tube cap, and the tube base forms a closed space. The window on the surface of the tube cap is equipped with an infrared optical filter. In the closed space, there are pyroelectric infrared sensitive elements, support components for fixing the infrared sensitive elements, and JFET (Junction Field-Effect Transistor) or IC (Integrated Circuit Chip) for signal processing. The support components and signal processing parts are fixed on the PCB circuit substrate, and the pins on the base are electrically connected to the through-hole pads of the PCB circuit substrate; there are 3 pins extending downward from the inside of the base. The chip-type pyroelectric infrared sensor mainly consists of a tube cap, a substrate or a base plate. The tube cap and the base plate or the base plate form a closed space. An infrared optical filter is installed in the window on the surface of the tube cap. In the closed space, there are pyroelectric infrared sensitive elements, supporting components for fixing the infrared sensitive elements, and JFET or IC for signal processing. The supporting components and signal processing parts are fixed on the base plate. The other side of the base plate in the closed space is provided with BGA balls for signal connection and SMT (Surface Mounted Technology) patch fixing.

[0004] Whether it is a plug-in type pyroelectric sensor or a patch type pyroelectric sensor, the tube cap is an important component of the pyroelectric sensor. In the prior art, the tube cap is a cylindrical tube-shaped structural part, but when other components (photosensitive elements, diodes, etc.) need to be installed on the substrate, the components need to be installed on the side of the cylindrical tube cap. Since the cylindrical tube cap and other original components occupy the area of ​​the substrate, the pyroelectric sensor is large in size, which is not conducive to the miniaturization design of the pyroelectric sensor. Utility Model Content

[0005] In order to overcome the technical problem in the prior art that the cylindrical tube cap and other original components occupy the area of ​​the substrate, resulting in a large volume of the pyroelectric sensor, the utility model provides a tube cap for a pyroelectric infrared sensor and a pyroelectric infrared sensor.

[0006] The utility model provides a tube cap for a pyroelectric infrared sensor, comprising a tube cap body, the tube cap body being provided with an internal space for accommodating an infrared sensitive element of the pyroelectric infrared sensor, the side wall of the tube cap body comprising at least one arc surface segment and at least one straight surface segment, the arc surface segment being used for positioning a circular lens of the pyroelectric infrared sensor;

[0007] The top surface of the tube cap body is also provided with an installation window communicating with the internal space, and the installation window is used for installing an infrared filter of the pyroelectric infrared sensor.

[0008] Optionally, a curved surface segment and a straight surface segment connecting the curved surface segment are provided on the side wall of the tube cap body.

[0009] Optionally, two arc surface segments and two straight surface segments connecting the arc surface segments are provided on the side wall of the tube cap body.

[0010] Optionally, a first flange extending away from the interior space is provided at the bottom of the straight surface section.

[0011] Optionally, a second flange extending away from the internal space is provided at the bottom of the arc surface segment.

[0012] Optionally, in the direction of the orthographic projection of the tube cap body, the arc angle of at least one of the arc surface segments is greater than or equal to π / 3.

[0013] Another embodiment of the utility model further provides a pyroelectric infrared sensor, comprising a substrate, an infrared sensitive element, an infrared filter and the above-mentioned pyroelectric infrared sensor cap; the infrared filter is installed in the installation window;

[0014] The tube cap body and the infrared sensitive element are both mounted on the substrate, and the infrared sensitive element is located in the internal space.

[0015] Optionally, the pyroelectric infrared sensor further comprises a first element and a circular lens coaxially arranged with the arc surface segment, and the first element is mounted on the substrate;

[0016] The tube cap body and the first element are both located in a circular ring, and the circular ring is the orthographic projection of the circular lens on the substrate.

[0017] Optionally, the radius of the circular lens is greater than or equal to the radius of the arc surface segment.

[0018] Optionally, the pyroelectric infrared sensor further comprises a signal processing component mounted on the substrate, and the signal processing component is electrically connected to both the infrared sensitive element and the first element.

[0019] In the utility model, the side wall of the tube cap body includes at least one arc surface segment and at least one straight surface segment, and the arc surface segment is used to position the circular lens of the pyroelectric infrared sensor; after the tube cap body is installed on the substrate, the circular lens is arranged on the top of the tube cap body and is coaxially arranged with the arc surface segment, the positive projection of the circular lens on the substrate is a circular ring, the tube cap body is located in the circular ring, and the first element close to the straight surface segment is also located in the circular ring, so that the tube cap body can reserve a part of space for installing the first element, which reduces the volume of the pyroelectric infrared sensor, improves the compactness of the pyroelectric infrared sensor, and is conducive to the miniaturized design of the pyroelectric infrared sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a tube cap for a pyroelectric infrared sensor provided by the first embodiment of the utility model;

[0021] Figure 2 It is a structural schematic diagram of a tube cap for a pyroelectric infrared sensor provided by the second embodiment of the utility model;

[0022] Figure 3 It is a schematic diagram of the explosion structure of the pyroelectric infrared sensor provided in the first embodiment of the utility model;

[0023] Figure 4 is a top view of a pyroelectric infrared sensor provided by the first embodiment of the utility model;

[0024] Figure 5 It is a front view of a pyroelectric infrared sensor provided in the second embodiment of the utility model.

[0025] Among them, 1. pipe cap body; 11. arc surface segment; 111. second flange; 12. straight surface segment; 121. first flange; 13. installation window; 2. substrate; 3. infrared sensitive element; 4. infrared filter; 5. first element; 6. ring; 7. signal processing components. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0027] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figure 1 and Figure 2 As shown, an embodiment of the utility model provides a pipe cap for a pyroelectric infrared sensor, including a pipe cap body 1, the pipe cap body 1 is provided with an internal space (not shown in the figure) for accommodating an infrared sensitive element 3 of the pyroelectric infrared sensor, and the side wall of the pipe cap body 1 includes at least one arc surface segment 11 and at least one straight surface segment 12, and the arc surface segment 11 is used to position the circular lens of the pyroelectric infrared sensor. It can be understood that the number of the arc surface segment 11 and the straight surface segment 12 can be set according to actual needs, and the arc surface segment 11 and the straight surface segment 12 are both part of the side surface of the pipe cap body 1, and the straight surface segment 12 is equivalent to a straight surface cut out on the cylindrical pipe cap body 1.

[0030] The top surface of the cap body 1 is also provided with an installation window 13 connected to the internal space, and the installation window 13 is used to install the infrared filter 4 of the pyroelectric infrared sensor. It can be understood that the shape of the infrared filter 4 can be circular, rectangular, or other polygonal. The infrared filter 4 can have optical properties of focusing. The infrared filter 4 can absorb visible light and allow infrared light to pass through, so that the infrared sensitive element 3 in the internal space can receive infrared light.

[0031] In the utility model, the side wall of the tube cap body 1 includes at least one arc surface segment 11 and at least one straight surface segment 12, and the arc surface segment 11 is used to position the circular lens of the pyroelectric infrared sensor; after the tube cap body 1 is installed on the substrate 2, and the circular lens is arranged on the top of the tube cap body 1 and coaxially arranged with the arc surface segment 11, the orthographic projection of the circular lens on the substrate 2 is a circular ring 6, and the tube cap body 1 is located in the circular ring 6, and the first element 5 close to the straight surface segment 12 is also located in the circular ring 6, so that the tube cap body 1 can reserve a part of space for installing the first element 5, which reduces the volume of the pyroelectric infrared sensor, improves the compactness of the pyroelectric infrared sensor, and is conducive to the miniaturized design of the pyroelectric infrared sensor.

[0032] It should be noted that the first element 5 may be a component such as a resistor or a diode of a pyroelectric infrared sensor, or may be other sensors.

[0033] In one embodiment, if Figure 1 As shown, a curved surface segment 11 and a straight surface segment 12 connecting the curved surface segment 11 are provided on the side wall of the pipe cap body 1. It can be understood that the design of a straight surface segment 12 is equivalent to cutting a straight surface on the cylindrical pipe cap body 1. In this embodiment, the design of a straight surface segment 12 ensures that the pipe cap body 1 has sufficient internal space while also allowing the pipe cap body 1 to reserve space for installing other components.

[0034] In one embodiment, if Figure 2 As shown, two arc surface segments 11 and two straight surface segments 12 connecting the arc surface segments 11 are provided on the side wall of the pipe cap body 1, and the two arc surface segments 11 are symmetrically arranged, and the two straight surface segments 12 are symmetrically arranged. It can be understood that the two straight surface segments 12 can be arranged on the front and back sides of the pipe cap body 1, and the two arc surface segments 11 can be arranged on the left and right sides of the pipe cap body 1. In this embodiment, the design of the two straight surface segments 12 allows the pipe cap body 1 to reserve two spaces for installing other components of the pyroelectric infrared sensor, further increasing the volume of the pyroelectric infrared sensor.

[0035] In one embodiment, if Figure 1 and Figure 2As shown, the bottom of the straight surface segment 12 is provided with a first flange 121 extending away from the internal space. Preferably, the bottom of the arc surface segment 11 is provided with a second flange 111 extending away from the internal space. It can be understood that the bottoms of the straight surface segment 12 and the arc surface segment 11 are both provided with flange structures. At this time, the bottom of the tube cap body 1 is provided with flanges extending outward all around, ensuring the stability and sealing of the tube cap body 1 installed on the substrate 2. It should be noted that the second flange 111 may be provided only at the bottom of the arc surface segment 11, while the first flange 121 is not provided at the bottom of the straight surface segment 12; or the first flange 121 may be provided only at the bottom of the straight surface segment 12, while the second flange 111 is not provided at the bottom of the arc surface segment 11.

[0036] In one embodiment, if Figure 1 and Figure 2 As shown, in the direction of the orthographic projection of the cap body 1, the arc angle of at least one of the arc surface segments 11 is greater than or equal to π / 3 (that is, the center angle of at least one of the arc surface segments 11 is greater than or equal to 60 degrees). In this embodiment, at least one of the arc surface segments 11 has a center angle greater than or equal to 60 degrees, so as to avoid that the center angles of all the arc surface segments 11 are relatively small, so that all the arc surface segments 11 are difficult to play the role of positioning the circular lens.

[0037] like Figure 3 and Figure 5 As shown, another embodiment of the utility model also provides a pyroelectric infrared sensor, including a substrate 2, an infrared sensitive element 3, an infrared filter 4 and the above-mentioned pyroelectric infrared sensor cap; it can be understood that the pyroelectric infrared sensor also includes a signal processing component 7 installed on the substrate 2 (the signal processing component 7 can be installed on the upper surface or the lower surface of the substrate 2), and the signal processing component 7 is electrically connected to the infrared sensitive element 3. The signal processing component 7 includes a JFET and an intelligent signal processing chip, an amplifier, an MCU and other integrated circuits; the substrate 2 also includes other signal processing components 7 for forming a highly integrated pyroelectric infrared sensor, and the other signal processing components 7 at least include: a power supply voltage stabilizing chip, an output signal control component, a photosensitive component, an analog or digital signal processing chip, and any one or more of passive components. Among them, the output signal control component includes any one or more of a triode, a field effect tube, a thyristor, and a relay, and the passive component includes at least any one or more of a resistor, a capacitor, and an inductor.

[0038] The top of the tube cap body 1 is provided with an installation window 13 communicating with the internal space, and the infrared filter 4 is installed in the installation window 13 ; it can be understood that the infrared filter 4 is sealed and installed in the installation window 13 .

[0039] The cap body 1 and the infrared sensitive element 3 are both mounted on the substrate 2, and the infrared sensitive element 3 is located in the internal space. It can be understood that the substrate 2 can play a role in sealing the bottom of the cap body 1, and the infrared filter 4 can play a role in sealing the top of the cap body 1, so that the infrared sensitive element 3 is located in the closed internal space.

[0040] Specifically, the working principle of the pyroelectric infrared sensor is as follows: the infrared sensitive element 3 detects the infrared light of external organisms through the infrared filter 4, and converts the received infrared radiation signal into a weak voltage signal through the signal processing component 7 on the substrate 2, which is converted by the signal circuit on the substrate 2 and output to the outside.

[0041] In the utility model, after the tube cap body 1 is installed on the substrate 2, a certain accommodation space is reserved at the position of the straight surface section 12 of the tube cap body 1, and components such as resistors and diodes of the pyroelectric infrared sensor can be installed in the accommodation space, thereby improving the compactness of the pyroelectric infrared sensor and facilitating the miniaturization design of the pyroelectric infrared sensor.

[0042] In one embodiment, if Figure 3 and Figure 4 As shown, the pyroelectric infrared sensor also includes a first element 5 and a circular lens (not shown in the figure) coaxially arranged with the arc surface segment 11, and the first element 5 is mounted on the substrate 2; it can be understood that the first element 5 includes but is not limited to any one or more of a power supply voltage stabilizing chip, an output component, a microcontroller, an analog or digital processing chip, a diode, a triode, a passive device, a switch, a potentiometer, etc.; the circular lens is arranged directly above the tube cap body 1 and outside the internal space.

[0043] The cap body 1 and the first element 5 are both located in a circular ring 6, and the circular ring 6 is the orthographic projection of the circular lens on the substrate 2. In the prior art, the orthographic projection of the cap body 1 provided with the straight surface section 12 on the substrate 2 usually coincides with the orthographic projection of the circular lens on the substrate 2; in this embodiment, due to the design of the straight surface section 12 on the cap body 1, the straight surface section 12 of the cap body 1 coincides with the space reserved for accommodating the first element 5, so that the cap body 1 and the first element 5 are both located within the orthographic projection range of the circular lens on the substrate 2, further ensuring the compactness of the pyroelectric infrared sensor.

[0044] In one embodiment, if Figure 4As shown, the radius of the circular lens is greater than or equal to the radius of the arc segment 11. Preferably, the radius of the circular lens is equal to the radius of the arc segment 11. In this embodiment, the circular lens is a conventional lens in the prior art, and there is no need to customize the lens specifically for the pyroelectric infrared sensor in the utility model; and the radius of the circular lens is greater than or equal to the radius of the arc segment, so that the orthographic projection of the circular lens on the substrate 2 has a large enough area to accommodate the cap body 1 and the first element 5.

[0045] In one embodiment, the first element 5 is a photosensitive element. It can be understood that the design of the photosensitive element enables the pyroelectric infrared sensor to integrate the function of a photosensitive sensor, and the infrared sensitive element 3 and the photosensitive element share the same substrate 2, which improves the versatility and applicability of the pyroelectric infrared sensor and reduces the manufacturing cost of the pyroelectric infrared sensor.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tube cap for a pyroelectric infrared sensor, characterized in that: The pipe cap body comprises a pipe cap body, the pipe cap body is provided with an internal space for accommodating an infrared sensitive element of the pyroelectric infrared sensor, the side wall of the pipe cap body comprises at least one arc surface segment and at least one straight surface segment, the arc surface segment is used to position a circular lens of the pyroelectric infrared sensor; The top surface of the tube cap body is also provided with an installation window communicating with the internal space, and the installation window is used for installing an infrared filter of the pyroelectric infrared sensor.

2. The tube cap for a pyroelectric infrared sensor according to claim 1, characterized in that: The side wall of the pipe cap body is provided with a curved surface segment and a straight surface segment connecting the curved surface segment.

3. The tube cap for a pyroelectric infrared sensor according to claim 1, characterized in that: Two arc surface segments and two straight surface segments connecting the arc surface segments are arranged on the side wall of the pipe cap body.

4. The tube cap for a pyroelectric infrared sensor according to claim 1, characterized in that: A first flange extending away from the inner space is provided at the bottom of the straight surface section.

5. The tube cap for a pyroelectric infrared sensor according to claim 1, characterized in that: A second flange extending away from the inner space is provided at the bottom of the arc surface segment.

6. The tube cap for a pyroelectric infrared sensor according to claim 1, characterized in that: In the direction of the orthographic projection of the tube cap body, the arc angle of at least one of the arc surface segments is greater than or equal to π / 3.

7. A pyroelectric infrared sensor, characterized in that: It comprises a substrate, an infrared sensitive element, an infrared filter and a tube cap for a pyroelectric infrared sensor according to any one of claims 1 to 6; the infrared filter is installed in the installation window; The tube cap body and the infrared sensitive element are both mounted on the substrate, and the infrared sensitive element is located in the internal space.

8. The pyroelectric infrared sensor according to claim 7, characterized in that: The pyroelectric infrared sensor further comprises a first element and a circular lens coaxially arranged with the arc surface segment, wherein the first element is mounted on the substrate; The tube cap body and the first element are both located in a circular ring, and the circular ring is the orthographic projection of the circular lens on the substrate.

9. The pyroelectric infrared sensor according to claim 8, characterized in that: The radius of the circular lens is greater than or equal to the radius of the arc surface segment.

10. The pyroelectric infrared sensor according to claim 8, characterized in that: The pyroelectric infrared sensor further comprises a signal processing component mounted on the substrate, and the signal processing component is electrically connected to the infrared sensitive element.

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