Infrared pyroelectric sensor, fire detector and gas analyzer

Abstract

The invention discloses an infrared pyroelectric sensor, a fire detector and a gas analyzer, and relates to the technical field of infrared sensors, a light filtering assembly is fixedly connected with a tube seat to form a sealed space; external light is filtered by the light filtering assembly and enters the sealed space, a first part of infrared light directly irradiates the sensitive element assembly, and / or a second part of infrared light is reflected to the sensitive element assembly through the light reflecting assembly, and the sensitive element assembly generates an infrared detection signal and outputs the infrared detection signal to the signal amplification circuit board. And an infrared detection signal is output after being amplified by the signal amplification circuit board. As the light reflecting assembly is arranged in the sealed space inside the light filtering assembly, infrared light irradiating into the sealed space at a large angle can be reflected to the sensitive element assembly through the light reflecting assembly, the effective visual angle of the infrared pyroelectric detector can be increased, meanwhile, the internal space of the infrared pyroelectric sensor can be reasonably utilized, and the detection accuracy is improved. The infrared pyroelectric sensor can be suitable for application scenes requiring a large effective visual angle and a small size of the infrared pyroelectric sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of infrared sensors, and in particular to an infrared pyroelectric sensor, a fire detector and a gas analyzer. Background Art

[0002] At present, fire detectors and gas analyzers generally use semiconductor detectors, electrochemical detectors, catalytic detectors, and pyroelectric detectors. Semiconductor detectors, electrochemical detectors, and catalytic detectors have the disadvantages of small output signal, short service life, and easy poisoning. Infrared pyroelectric sensors have the advantages of large signal, long service life, and no poisoning, and have been widely used.

[0003] However, when infrared pyroelectric sensors are used in flame detectors, fire monitors, etc., there is still a problem of small detection angle. The existing infrared pyroelectric sensors have a narrow detection angle of view. Infrared radiation within the detection angle of view can be detected by the infrared sensor, but infrared radiation outside the detection angle of view cannot be detected by the infrared sensor. Therefore, increasing the effective angle of view of infrared pyroelectric detectors and overcoming the above shortcomings are technical problems that need to be solved in this field. Summary of the invention

[0004] The present invention provides an infrared pyroelectric sensor, a fire detector and a gas analyzer, which can increase the effective viewing angle of the infrared pyroelectric detector. At the same time, by rationally utilizing the internal space of the infrared pyroelectric sensor, the infrared pyroelectric sensor can be applied to application scenarios requiring the infrared pyroelectric sensor to have a large effective viewing angle and a small size.

[0005] In a first aspect, an embodiment of the present invention provides an infrared pyroelectric sensor, comprising: a filter component, a sensitive element component, a reflective component, a signal amplification circuit board, and a tube holder;

[0006] The filter assembly is fixedly connected to the tube holder to form a sealed space; the signal amplification circuit board, the sensitive component assembly and the reflective component are coaxially arranged inside the filter assembly in a direction away from the tube holder in sequence;

[0007] The external light is filtered by the filter component and incident into the sealed space, the first part of the infrared light is directly irradiated on the sensitive component, and / or the second part of the infrared light is reflected on the sensitive component by the reflective component, the sensitive component generates an infrared detection signal and outputs it to the signal amplifying circuit board, and the infrared detection signal is amplified by the signal amplifying circuit board and then output.

[0008] Optionally, the reflective assembly includes at least two reflective wafers and reflective wafer fixing grooves disposed opposite to each other;

[0009] The reflective chip fixing groove is located on the signal amplifying circuit board, and a partial area of ​​the reflective chip is fixed in the reflective chip fixing groove.

[0010] Optionally, the sensitive element assembly includes a light absorption sensitive element, a reference sensitive element and a sensitive element supporting firmware;

[0011] The sensitive element supporting firmware is located on the inner side of the reflective chip fixing groove, the light absorbing sensitive element and the reference sensitive element are both located on the inner side of the sensitive element supporting firmware, the reference sensitive element is arranged on the side of the sensitive element component close to the signal amplifying circuit board, and the light absorbing sensitive element is arranged on the side of the sensitive element component away from the signal amplifying circuit board.

[0012] Optionally, there is a preset angle between the reflective chip and the axial direction of the infrared pyroelectric sensor, and the preset angle is less than or equal to 45°.

[0013] Optionally, the filter assembly includes an infrared filter and a tube cap;

[0014] There is an opening at the top of the tube cap, and the infrared filter is located in the opening.

[0015] Optionally, the infrared filter is bonded in the opening by conductive adhesive.

[0016] Optionally, the signal amplifying circuit board includes a signal amplifying circuit;

[0017] The signal amplifying circuit comprises a filtering unit and a signal amplifying unit, the filtering unit comprises a resistor and a capacitor, and the signal amplifying unit comprises an integrated amplifier.

[0018] Optionally, the tube holder is welded to the filter assembly to form the sealed space; the tube holder is also bonded to the signal amplification circuit board by conductive glue.

[0019] In a second aspect, an embodiment of the present invention further provides a fire detector, comprising the infrared pyroelectric sensor described in any embodiment of the first aspect.

[0020] In a third aspect, an embodiment of the present invention further provides a gas analyzer, comprising the infrared pyroelectric sensor described in any embodiment of the first aspect.

[0021] The embodiment of the present invention discloses an infrared pyroelectric sensor, a fire detector and a gas analyzer; the filter assembly is fixedly connected to the tube holder to form a sealed space; the external light is filtered by the filter assembly and incident into the sealed space, the first part of the infrared light is directly irradiated on the sensitive component assembly, and / or the second part of the infrared light is reflected on the sensitive component assembly by the reflective assembly, the sensitive component assembly generates an infrared detection signal and outputs it to the signal amplification circuit board, and the infrared detection signal is amplified by the signal amplification circuit board and then output. Since the reflective assembly is arranged in the sealed space inside the filter assembly, the infrared light irradiated into the sealed space from a large angle can be reflected on the sensitive component assembly by the reflective assembly, thereby increasing the effective viewing angle of the infrared pyroelectric detector, and at the same time, the internal space of the infrared pyroelectric sensor can be reasonably used, so that the infrared pyroelectric sensor can be applied to the application scene requiring the infrared pyroelectric sensor to have a large effective viewing angle under the condition of a small volume.

[0022] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 An overall exploded diagram of an infrared pyroelectric sensor provided by an embodiment of the present invention;

[0025] Figure 2 A cross-sectional view of an infrared pyroelectric sensor provided by an embodiment of the present invention;

[0026] Figure 3 An internal diagram of an infrared pyroelectric sensor provided by an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of signal transmission of an infrared pyroelectric sensor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] Figure 1 An overall exploded view of an infrared pyroelectric sensor provided by an embodiment of the present invention, Figure 2 A cross-sectional view of an infrared pyroelectric sensor provided by an embodiment of the present invention, Figure 3 An internal diagram of an infrared pyroelectric sensor provided by an embodiment of the present invention, referring to Figure 1-3 The infrared pyroelectric sensor includes: a filter component 100, a sensitive component 200, a reflective component 300, a signal amplifying circuit board 400 and a tube holder 500; the filter component 100 is fixedly connected to the tube holder 500 to form a sealed space; the signal amplifying circuit board 400, the sensitive component 200 and the reflective component 300 are coaxially arranged inside the filter component 100 in a direction away from the tube holder 500.

[0031] Figure 4 A signal transmission diagram of an infrared pyroelectric sensor provided by an embodiment of the present invention, referring to Figure 1-4 The external light A is filtered by the filter component 100 and incident into the sealed space, the first part of the infrared light A1 is directly irradiated on the sensitive component 200, and / or the second part of the infrared light A2 is reflected on the sensitive component 200 by the reflective component 300, and the sensitive component 200 generates an infrared detection signal and outputs it to the signal amplifying circuit board 400, and the infrared detection signal is amplified by the signal amplifying circuit board 400 and then output.

[0032] It should be noted that, since the sensitive component 200 is relatively small, part of the infrared light (the second part of the infrared light A2) of the external light A after being filtered by the filter component 100 can irradiate into the sealed space of the infrared pyroelectric sensor, but cannot irradiate onto the sensitive component 200, and this part of the light cannot cause the sensitive component 200 to generate a signal. The present invention can irradiate the second part of the infrared light A2 onto the surface of the sensitive component 200 through optical effects such as reflection and diffuse reflection by setting the reflective component 300, so that the sensitive component 200 absorbs more heat generated by the irradiation of the second part of the infrared light A2, thereby generating a large infrared detection signal. The main function of the reflective component 300 is to expand the test angle of the infrared pyroelectric sensor, so that the second part of the infrared light A2 that cannot be irradiated onto the sensitive component 200 at a large angle is irradiated onto the sensitive component 200 by the optical effect generated by the reflective component 300, so that the object to be measured can be detected.

[0033] In the embodiment of the present invention, since the reflective component 300 is arranged in the sealed space inside the filter component 100, the infrared light irradiated into the sealed space from a large angle can be reflected to the sensitive element component 200 through the reflective component 300, thereby increasing the effective viewing angle of the infrared pyroelectric detector. At the same time, the internal space of the infrared pyroelectric sensor can be reasonably utilized, so that the infrared pyroelectric sensor can be applied to application scenarios requiring a large effective viewing angle of the infrared pyroelectric sensor under the condition of a small size.

[0034] Optionally, based on the above embodiment, continue to refer to Figure 1-3 The reflective component 300 includes at least two reflective chips 310 and a reflective chip fixing groove 320 which are arranged opposite to each other; the reflective chip fixing groove 320 is located on the signal amplifying circuit board 400 , and a partial area of ​​the reflective chip 310 is fixed in the reflective chip fixing groove 320 .

[0035] It is understandable that the number of reflective chips 310 in the reflective assembly 300 can be freely selected according to the use requirements. For example, the number of reflective chips 310 can be set to two, four, six, etc. ( Figure 1-3 The number of the reflective wafers 310 shown in the figure is two). The surface of the reflective wafer 310 close to the sensitive component 200 includes a reflective film or a reflective coating, and the shape of the surface of the reflective wafer 310 close to the sensitive component 200 can be a plane or a concave surface.

[0036] In the embodiment of the present invention, by providing the reflective chip 310, some infrared light at a large angle that cannot directly irradiate the sensitive component assembly 200 can be reflected to the sensitive component assembly 200, so that the sensitive component assembly 200 generates more heat due to the irradiation of the infrared light, thereby obtaining a larger infrared detection signal, thereby increasing the effective viewing angle of the infrared pyroelectric detector. The reflective chip fixing groove 320 is located on the signal amplifying circuit board 400, which can reasonably utilize the internal space of the infrared pyroelectric sensor, save space and cost, and make the infrared pyroelectric sensor small in size and suitable for application scenarios requiring a large effective viewing angle of the infrared pyroelectric sensor.

[0037] Optionally, based on the above embodiment, continue to refer to Figure 1 and Figure 2 The sensitive element assembly 200 includes a light absorbing sensitive element 210, a reference sensitive element 220, and a sensitive element supporting fixture 230. The sensitive element supporting fixture 230 is located inside the reflective wafer fixing groove 320, the light absorbing sensitive element 210 and the reference sensitive element 220 are both located inside the sensitive element supporting fixture 230, the reference sensitive element 220 is arranged on a side of the sensitive element assembly 200 close to the signal amplifying circuit board 400, and the light absorbing sensitive element 210 is arranged on a side of the sensitive element assembly 200 away from the signal amplifying circuit board 400.

[0038] It is understandable that in the embodiment of the present invention, the light-absorbing sensitive element 210 of the infrared pyroelectric sensor generates heat after receiving infrared light. Within a unit time, the surface heat of the light-absorbing sensitive element 210 changes, and the light-absorbing sensitive element 210 itself generates polarization, which can convert the heat into an electrical signal output. However, changes in ambient temperature will also cause the infrared pyroelectric sensor to generate signals. In order to eliminate the influence of ambient temperature changes on the infrared pyroelectric sensor, a reference sensitive element 220 is provided. The reference sensitive element 220 can detect the signal generated by the ambient temperature change and offset the signal generated by the light-absorbing sensitive element 210 due to the ambient temperature change. This ensures that the signal detected by the sensitive element assembly 200 is the required infrared detection signal. For a fire detector, it is the flame signal for inspection, and for a gas analyzer, it is the change in the amount of infrared light absorbed by the gas.

[0039] The embodiment of the present invention can eliminate the influence of the signal generated by the ambient temperature change on the accuracy of the infrared detection signal detected by the sensitive element component 200, thereby improving the detection accuracy of the infrared pyroelectric sensor.

[0040] Optionally, based on the above embodiment, there is a preset angle between the reflective chip 310 and the axial direction of the infrared pyroelectric sensor in the embodiment of the present invention, and the preset angle is less than or equal to 45°.

[0041] There is a preset angle between the reflective chip 310 and the axial direction of the infrared pyroelectric sensor, the preset angle can be adjusted, and a glue adhesive is used to fix a part of the reflective chip 310 in the reflective chip fixing groove 320. It can be understood that when the preset angle is less than or equal to 45°, the reflective chip 310 can achieve a better reflective effect.

[0042] In the embodiment of the present invention, there is a preset angle between the reflective chip 310 and the axial direction of the infrared pyroelectric sensor, and the preset angle is less than or equal to 45°, which can not only expand the test angle of the infrared pyroelectric sensor, but also increase the infrared detection signal of the infrared pyroelectric sensor.

[0043] Optionally, based on the above embodiment, continue to refer to Figure 1 and Figure 2 The filter assembly 100 includes an infrared filter 110 and a tube cap 120 ; there is an opening 121 at the top of the tube cap 120 , and the infrared filter 110 is located in the opening 121 .

[0044] It can be understood that there is an opening 121 on the top of the tube cap 120 for supporting the infrared filter 110. The infrared filter 110 is arranged in the opening 121, and a sealed space can be formed after the filter assembly 100 and the tube holder 500 are fixedly connected, thereby shielding the interference of external factors such as electromagnetic and static electricity on the infrared pyroelectric sensor, thereby improving the detection accuracy of the infrared pyroelectric sensor.

[0045] Optionally, based on the above embodiment, the infrared filter 110 in the embodiment of the present invention is bonded in the opening 121 by conductive adhesive.

[0046] In the embodiment of the present invention, the infrared filter 110 is bonded to the opening 121 at the top of the tube cap 120 using conductive adhesive, which can better shield the interference of external factors such as electromagnetic and static electricity on the infrared pyroelectric sensor and further improve the detection accuracy of the infrared pyroelectric sensor.

[0047] Optionally, based on the above embodiment, continue to refer to Figure 1 and Figure 4 The signal amplifying circuit board 400 includes a signal amplifying circuit 410; the signal amplifying circuit 410 includes a filtering unit 411 and a signal amplifying unit 412. Exemplarily, the filtering unit 411 includes a resistor and a capacitor, and the signal amplifying unit 412 includes an integrated amplifier.

[0048] It can be understood that the embodiment of the present invention does not limit the specific structure of the filtering unit 411 and the signal amplifying unit 412. It is sufficient to select a filtering unit 411 that includes a resistor and a capacitor and can filter the infrared detection signal, and an amplifying unit 412 that includes an integrated amplifier and can amplify the filtered infrared detection signal.

[0049] The embodiment of the present invention sets a signal amplifying circuit 410, which includes a filtering unit 411 and a signal amplifying unit 412. The infrared detection signal generated by the sensitive component 200 can be output after filtering and amplification. The circuit is simple, and weak infrared light can also be effectively identified, thereby increasing the recognition sensitivity of the infrared pyroelectric sensor, which is beneficial for fire detectors to expand the detection angle and detection distance, and is beneficial for gas analyzers to detect low concentrations.

[0050] Optionally, based on the above embodiment, in an embodiment of the present invention, the tube holder 500 is welded to the filter assembly 100 to form a sealed space; the tube holder 500 is also bonded to the signal amplifying circuit board 400 by conductive glue.

[0051] The tube holder 500 may include a signal transmission terminal, a power supply terminal and a ground terminal. The tube holder 500 is bonded to the signal amplifying circuit board 400 by conductive adhesive, so that the tube holder 500 can provide voltage and transmit signals to the signal amplifying circuit board 400. The tube holder 500 is welded to the filter assembly 100 to form a sealed space, which can achieve a better sealing effect for the infrared pyroelectric sensor.

[0052] In summary, in the embodiment of the present invention, by setting the reflective chip 310, some infrared light at a large angle that cannot directly irradiate the sensitive element assembly 200 can be reflected to the sensitive element assembly 200, so that the sensitive element assembly 200 generates more heat due to the irradiation of infrared light, thereby obtaining a larger infrared detection signal, thereby increasing the effective viewing angle of the infrared pyroelectric detector. The reflective chip fixing groove 320 is located on the signal amplification circuit board 400, which can reasonably utilize the internal space of the infrared pyroelectric sensor, save space and cost, and make the infrared pyroelectric sensor small in size. Under the condition of application scenarios requiring a large effective viewing angle of the infrared pyroelectric sensor. By setting the reference sensitive element 220, the signal generated by the change in ambient temperature is detected, and the signal generated by the light-absorbing sensitive element 210 due to the change in ambient temperature is offset. It can ensure that the signal detected by the sensitive element assembly 200 is the required infrared detection signal, and can eliminate the influence of the signal generated by the change in ambient temperature on the accuracy of the infrared detection signal detected by the sensitive element assembly 200, thereby improving the detection accuracy of the infrared pyroelectric sensor. There is a preset angle between the reflective chip 310 and the axial direction of the infrared pyroelectric sensor, and the preset angle is less than or equal to 45°, which can achieve a good reflective effect, not only can the test angle of the infrared pyroelectric sensor be expanded, but also the infrared detection signal of the infrared pyroelectric sensor can be increased. The infrared filter 110 is arranged in the opening 121, and a sealed space can be formed after the filter assembly 100 and the tube holder 500 are fixedly connected, so that the interference of external factors such as electromagnetic and static electricity on the infrared pyroelectric sensor can be shielded, and the detection accuracy of the infrared pyroelectric sensor can be improved. The infrared filter 110 is bonded to the opening 121 on the top of the tube cap 120 with conductive glue, which can better shield the interference of external factors such as electromagnetic and static electricity on the infrared pyroelectric sensor, and further improve the detection accuracy of the infrared pyroelectric sensor. By setting the signal amplification circuit 410, the signal amplification circuit 410 includes a filtering unit 411 and a signal amplification unit 412, and the infrared detection signal generated by the sensitive component 200 can be filtered and amplified before output. The circuit is simple, and weak infrared light can be effectively identified, which increases the recognition sensitivity of the infrared pyroelectric sensor, is beneficial to the fire detector to expand the detection angle and detection distance, and is beneficial to the gas analyzer to detect low concentrations. The tube holder 500 is welded with the filter component 100 to form a sealed space, which can achieve a better sealing effect for the infrared pyroelectric sensor.

[0053] An embodiment of the present invention further provides a fire detector, comprising the infrared pyroelectric sensor of any of the above embodiments.

[0054] Since the fire detector provided in the embodiment of the present invention includes the infrared pyroelectric sensor of any of the above embodiments, it has the same beneficial effects. For the contents not described in detail in the embodiment of the present invention, reference may be made to the infrared pyroelectric sensor provided in the above embodiments.

[0055] An embodiment of the present invention further provides a gas analyzer, comprising the infrared pyroelectric sensor of any of the above embodiments.

[0056] Since the gas analyzer provided in the embodiment of the present invention includes the infrared pyroelectric sensor of any of the above embodiments, it has the same beneficial effects. For the contents not described in detail in the embodiment of the present invention, reference may be made to the infrared pyroelectric sensor provided in the above embodiments.

[0057] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An infrared pyroelectric sensor, characterized in that: include: Filter components, sensitive components, reflective components, signal amplification circuit boards and tube holders; The filter assembly is fixedly connected to the tube holder to form a sealed space; The signal amplifying circuit board, the sensitive component assembly and the reflective assembly are coaxially arranged inside the filter assembly in a direction away from the tube holder in sequence; The external light is filtered by the filter component and incident into the sealed space, the first part of the infrared light is directly irradiated on the sensitive component, and / or the second part of the infrared light is reflected on the sensitive component by the reflective component, the sensitive component generates an infrared detection signal and outputs it to the signal amplifying circuit board, and the infrared detection signal is amplified by the signal amplifying circuit board and then output.

2. The infrared pyroelectric sensor according to claim 1, characterized in that: The reflective assembly comprises at least two reflective wafers arranged opposite to each other and a reflective wafer fixing groove; The reflective chip fixing groove is located on the signal amplifying circuit board, and a partial area of ​​the reflective chip is fixed in the reflective chip fixing groove.

3. The infrared pyroelectric sensor according to claim 2, characterized in that: The sensitive element assembly includes a light absorbing sensitive element, a reference sensitive element and a sensitive element supporting firmware; The sensitive element supporting firmware is located on the inner side of the reflective chip fixing groove, the light absorbing sensitive element and the reference sensitive element are both located on the inner side of the sensitive element supporting firmware, the reference sensitive element is arranged on the side of the sensitive element component close to the signal amplifying circuit board, and the light absorbing sensitive element is arranged on the side of the sensitive element component away from the signal amplifying circuit board.

4. The infrared pyroelectric sensor according to claim 3, characterized in that: There is a preset angle between the reflective chip and the axial direction of the infrared pyroelectric sensor, and the preset angle is less than or equal to 45°.

5. The infrared pyroelectric sensor according to claim 1, characterized in that: The filter assembly includes an infrared filter and a tube cap; There is an opening at the top of the tube cap, and the infrared filter is located in the opening.

6. The infrared pyroelectric sensor according to claim 5, characterized in that: The infrared filter is bonded in the opening by conductive adhesive.

7. The infrared pyroelectric sensor according to claim 1, characterized in that: The signal amplification circuit board includes a signal amplification circuit; The signal amplifying circuit comprises a filtering unit and a signal amplifying unit, the filtering unit comprises a resistor and a capacitor, and the signal amplifying unit comprises an integrated amplifier.

8. The infrared pyroelectric sensor according to claim 1, characterized in that: The tube seat is welded to the filter assembly to form the sealed space; the tube seat is also bonded to the signal amplification circuit board through conductive glue.

9. A fire detector, characterized in that: The infrared pyroelectric sensor comprises the infrared pyroelectric sensor as described in any one of claims 1 to 8.

10. A gas analyzer, characterized in that: The infrared pyroelectric sensor comprises the infrared pyroelectric sensor as described in any one of claims 1 to 8.

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