Photoelectric smoke detector

Abstract

The utility model relates to a photoelectric smoke detector which comprises a base, a circuit board, a cover plate, at least one light source piece and at least one light sensitive piece. The circuit board faces one side of the base. The cover plate is arranged on the other side of the base. A labyrinth structure assembly is arranged between the cover plate and the base, and a detection cavity is defined by the labyrinth structure assembly in the circumferential direction. A diffuse reflection area is arranged on the side, facing the base, of the cover plate. The light source piece comprises a main lamp body and a first pin. The main lamp body is inserted into the base and provided with a transmitting end and a first connecting end which are opposite to each other, and the transmitting end of the main lamp body is opposite to the diffuse reflection area. In the assembling process, due to the fact that the first connecting end of the main lamp body and the second connecting end of the light sensing part abut against the circuit board in the limiting mode, the first pin and the second pin can be fixedly connected to the circuit board through wave soldering machining, and manual positioning and manual welding needed in the light source piece and the light sensing piece in the assembling process are avoided; and the production and assembly process of the photoelectric smoke detector is simplified.

Description

Technical Field

[0001] This application relates to the field of fire monitoring technology, and in particular to a photoelectric smoke detector. Background Technology

[0002] Smoke detectors are commonly used fire detection devices. To prevent and monitor fires, multiple smoke detectors are usually installed in locations such as the ceiling of rooms and corridors. These smoke detectors detect fire phenomena around their respective installation locations.

[0003] Photoelectric smoke detectors detect smoke based on the principle of optical scattering. Within a labyrinthine structure, the detector contains an emitting element that emits detection light and a receiving element that receives the light. When there is no smoke inside the labyrinthine structure, the receiving element cannot receive the detection light due to the direction of its emission. When smoke enters the labyrinthine structure, the detection light is scattered by particles, and some of the light reaches the receiving element, causing it to generate a corresponding current signal and triggering an alarm.

[0004] However, in traditional photoelectric smoke detectors, in order to avoid the detection light shining directly onto the receiving element, the optical axis of the emitting element and the optical axis of the receiving element need to form a certain angle relationship, which makes the production and assembly process of photoelectric smoke detectors more complicated. Utility Model Content

[0005] Based on this, the present invention provides a photoelectric smoke detector that can solve or at least alleviate the above-mentioned technical problems.

[0006] This utility model provides a photoelectric smoke detector, comprising:

[0007] Base;

[0008] The circuit board faces the side of the base;

[0009] A cover plate is disposed on the other side of the base; a maze structure assembly is provided between the cover plate and the base; the maze structure assembly defines a detection cavity in the circumferential direction; a diffuse reflection area is provided on the side of the cover plate facing the base;

[0010] At least one light source component; the light source component includes a main lamp body and a first pin, the main lamp body is inserted into the base, the main lamp body has a corresponding emitting end and a first connecting end, the first connecting end of the main lamp body abuts against the circuit board, and the first connecting end of the main lamp body is connected to the first pin; the first pin is inserted into the circuit board; the emitting end of the main lamp body is positioned opposite to the diffuse reflection area; and

[0011] At least one photosensitive element; the photosensitive element includes a photosensitive part and a second pin, the photosensitive part being inserted into the base; the photosensitive part having an opposing receiving end and a second connecting end, the second connecting end of the photosensitive part abutting against the circuit board, the second connecting end of the photosensitive part being connected to a second pin; the second pin being inserted into the circuit board; the receiving end of the photosensitive part and the cover plate being disposed opposite to each other on the side facing the base.

[0012] The photoelectric smoke detector of this application has an optical axis of the light source element that is approximately parallel to the relative direction between the emitting end and the first connecting end, and an optical axis of the photosensitive element that is approximately parallel to the relative direction between the receiving end and the second connecting end. Since the circuit board and cover plate are respectively disposed on opposite sides of the base, the first connecting end of the main lamp body faces the circuit board, the emitting end and the diffuse reflection area are opposite each other, the second connecting end of the photosensitive part faces the circuit board, and the receiving end and the cover plate are opposite each other facing the base, the optical axis of the light source element is approximately parallel to the optical axis of the photosensitive element, and the optical axes of both the light source element and the photosensitive element are approximately perpendicular to the circuit board. In use, the main lamp body emits detection light. After reaching the diffuse reflection area of ​​the cover plate, the detection light undergoes diffuse reflection, scattering the detection light around the detection cavity and preventing the detection light from directly reaching the receiving end of the photosensitive part. During the assembly process, after the first pin and the second pin are inserted into the through holes of the circuit board, the first connecting end of the main lamp body and the second connecting end of the photosensitive part form a limiting contact with the circuit board. Therefore, the first pin and the second pin can be fixedly connected to the circuit board by wave soldering, avoiding the need for manual positioning and manual soldering of the light source and photosensitive parts during the assembly process, thus simplifying the production and assembly process of the photoelectric smoke detector.

[0013] In one embodiment, the cover plate has a plurality of cone-shaped protrusions in the diffuse reflection region.

[0014] In one embodiment, the cover plate has a plurality of grooves formed in the diffuse reflection region, the interior space of the grooves being narrowed along the depth direction.

[0015] In one embodiment, the circuit board has a plurality of through holes; the first pin and the second pin are respectively inserted into the plurality of through holes; the inner diameter of the plurality of through holes corresponds to the outer diameter of the first pin or the outer diameter of the second pin.

[0016] In one embodiment, the base has at least two cylindrical portions; the main lamp body and the photosensitive part are respectively inserted into the at least two cylindrical portions; the depth of the cylindrical portion is greater than the length of the main lamp body and the length of the photosensitive part.

[0017] In one embodiment, the at least one light source includes an LED1 for emitting infrared light and an LED2 for emitting blue light.

[0018] In one embodiment, the distance between the light source LED1 and the photosensitive part is greater than the distance between the light source LED2 and the photosensitive part; the angle between the opposing direction between the light source LED1 and the photosensitive part and the relative direction between the light source LED2 and the photosensitive part is greater than zero.

[0019] In one embodiment, the circuit board further includes a main control chip U1; the main control chip U1 has a first control pin and a second control pin; the light source LED1 and the light source LED2 are light-emitting diodes; the anodes of the light source LED1 and the light source LED2 are respectively electrically connected to a reference voltage point; the cathode of the light source LED1 is electrically connected to the first control pin; and the cathode of the light source LED2 is electrically connected to the second control pin.

[0020] In one embodiment, the main control chip U1 is provided with a first detection pin and a second detection pin; the photosensitive element is electrically connected between the first detection pin and the second detection pin.

[0021] In one embodiment, it further includes light-emitting diodes LED3 and LED4; the main control chip U1 is provided with a third control pin and a fourth control pin; the anodes of LED3 and LED4 are respectively electrically connected to a reference voltage point; the cathode of LED3 is electrically connected to the third control pin of the main control chip U1; and the cathode of LED4 is electrically connected to the fourth control pin of the main control chip U1. Attached Figure Description

[0022] Figure 1 This is a three-dimensional schematic diagram of a photoelectric smoke detector according to an embodiment of this application.

[0023] Figure 2 for Figure 1 The photoelectric smoke detector shown is a three-dimensional schematic diagram from another angle.

[0024] Figure 3 for Figure 1 The diagram shown is an exploded view of a photoelectric smoke detector.

[0025] Figure 4 for Figure 1 The diagram shown is an exploded view of the photoelectric smoke detector from another angle.

[0026] Figure 5 for Figure 1 The image shows a three-dimensional cross-sectional view of a photoelectric smoke detector.

[0027] Figure 6 This is a schematic diagram of the circuit structure of the electrical part of a photoelectric smoke detector according to an embodiment of this application.

[0028] Figure 7 This is a circuit diagram of a photoelectric smoke detector according to an embodiment of this application.

[0029] Reference numerals: 100, photoelectric smoke detector; 20, base; 21, cylindrical part; 22, positioning hole; 30, circuit board; 31, through hole; 40, cover plate; 41, diffuse reflection area; 42, protrusion; 50, labyrinth structure assembly; 51, detection cavity; 52, light shield; 53, connecting post; 61, main lamp body; 611, transmitter; 612, first connection end; 62, first pin; PD1, photosensitive element; 71, photosensitive part; 711, receiver; 712, second connection end; 72, second pin; 81, power supply unit; 82, electroacoustic unit; 83, input button. Detailed Implementation

[0030] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, direct connections, indirect connections via an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0033] The technical solutions provided by the embodiments of this application are described below with reference to the accompanying drawings.

[0034] Combination Figure 1 and Figure 2 As shown, this application provides a photoelectric smoke detector 100 for monitoring smoke. When smoke enters the interior of the photoelectric smoke detector 100, the detector senses the smoke through photoelectric principles and triggers an alarm, enabling users to promptly detect a fire.

[0035] Specifically, in combination Figures 3 to 5 As shown, the photoelectric smoke detector 100 includes: a base 20, a circuit board 30, a cover plate 40, at least one light source, and at least one photosensitive element PD1. The circuit board 30 faces the base 20. The cover plate 40 is disposed on the other side of the base 20. A labyrinth structure assembly 50 is provided between the cover plate 40 and the base 20, and the labyrinth structure assembly 50 defines a detection cavity 51 circumferentially. The cover plate 40 has a diffuse reflection area 41 on the side facing the base 20. The light source includes a main lamp body 61 and a first pin 62. The main lamp body 61 is inserted into the base 20 and has opposing emitting ends 611 and first connecting ends 612. The emitting ends 611 of the main lamp body 61 are opposite to the diffuse reflection area 41. The first connecting end 612 of the main lamp body 61 abuts against the circuit board 30 and is connected to the first pin 62. The photosensitive element PD1 includes a photosensitive part 71 and a second pin 72. A photosensitive unit 71 is inserted into the base 20. The photosensitive unit 71 has a receiving end 711 and a second connecting end 712. The receiving end 711 of the photosensitive unit 71 is positioned opposite the cover plate 40 on the side facing the base 20. The second connecting end 712 of the photosensitive unit 71 abuts against the circuit board 30 and is connected to a second pin 72. The second pin 72 and the first pin 62 are respectively inserted into the circuit board 30.

[0036] The photoelectric smoke detector 100 of this application has an optical axis of the light source element that is approximately parallel to the relative direction between the emitting end 611 and the first connecting end 612, and an optical axis of the photosensitive element PD1 that is approximately parallel to the relative direction between the receiving end 711 and the second connecting end 712. Since the circuit board 30 and the cover plate 40 are respectively disposed on opposite sides of the base 20, the first connecting end 612 of the main lamp body 61 faces the circuit board 30, the emitting end 611 and the diffuse reflection area 41 are disposed opposite each other, the second connecting end 712 of the photosensitive part 71 faces the circuit board 30, and the receiving end 711 and the cover plate 40 are disposed opposite each other facing one side of the base 20, the optical axis of the light source element is approximately parallel to the optical axis of the photosensitive element PD1, and the optical axes of the light source element and the photosensitive element PD1 are approximately perpendicular to the circuit board 30. In use, the main lamp body 61 is used to emit detection light. The detection light undergoes diffuse reflection upon reaching the diffuse reflection area 41 of the cover plate 40, causing it to scatter around the detection cavity 51 and preventing it from directly reaching the receiving end 711 of the photosensitive part 71. During assembly, when the first pin 62 and the second pin 72 are respectively inserted into the through holes 31 of the circuit board 30, the first connecting end 612 of the main lamp body 61 and the second connecting end 712 of the photosensitive part 71 form limiting contact with the circuit board 30. Therefore, the first pin 62 and the second pin 72 can be fixedly connected to the circuit board 30 by wave soldering, avoiding the need for manual positioning and soldering of the light source and photosensitive part PD1 during assembly, thus simplifying the production and assembly process of the photoelectric smoke detector 100.

[0037] Understandably, when smoke enters the detection chamber 51, some of the smoke may reach a position opposite to the receiving end 711 of the photosensitive unit 71. This part of the smoke diffuses the detection light, causing some of the detection light to be reflected to the receiving end 711 of the photosensitive unit 71. The photosensitive element PD1 generates a corresponding smoke detection signal and triggers an alarm.

[0038] In some implementations, combined Figure 3 and Figure 4 As shown, the maze structure assembly 50 includes a plurality of light-shielding plates 52. The plurality of light-shielding plates 52 are distributed at intervals along the circumference. Specifically, the cross-section of the light-shielding plates 52 is bent, so that smoke can enter the detection cavity 51 through the gap between adjacent light-shielding plates 52, while preventing external light from entering the detection cavity 51, thus avoiding the triggering effect of external light on the photosensitive part 71.

[0039] In some implementations, combined Figure 4As shown, one of the maze structure components 50 and the base 20 is connected by a connecting post 53, and the other is provided with a positioning hole 22. When the connecting post 53 is inserted into the positioning hole 22, the cover plate 40 and the maze structure component 50 can be positioned and connected relative to the base 20. Optionally, the connecting post 53, the maze structure component 50 and the cover plate 40 are integrally connected.

[0040] In some implementations, combined Figure 4 As shown, the cover plate 40 has a plurality of conical protrusions 42 formed in the diffuse reflection area 41. Understandably, the protrusions 42 have a large end and a small end, pointing towards the base 20 in the direction from the large end to the small end. When the detection light emitted by the light source shines on the outer peripheral surface of the plurality of protrusions 42, the plurality of protrusions 42 can diffusely reflect the detection light in all directions, thereby avoiding direct reflection of the detection light to the photosensitive part 71 of the photosensitive element PD1.

[0041] For example, the cone angle of the protrusion 42 is less than 45°. Alternatively, the cone angle of the protrusion 42 is 30°.

[0042] In some embodiments, the cover plate 40 has a plurality of grooves formed in the diffuse reflection region 41. The interior space of the grooves narrows and transitions along the depth direction. Understandably, the interior space of the grooves is conical or frustum-shaped. The depth direction of the grooves is away from the base 20. When the detection light emitted by the light source illuminates the plurality of grooves, the inner wall surface of the grooves can diffusely reflect the detection light in all directions, thereby avoiding direct reflection of the detection light to the photosensitive part 71 of the photosensitive element PD1.

[0043] Optionally, the diffuse reflection area 41 is distributed in the middle part of the cover plate 40, which helps the diffuse reflection area 41 to uniformly diffuse the detection light to the surroundings.

[0044] In some implementations, combined Figure 4 As shown, the circuit board 30 has a plurality of through holes 31. The first pin 62 and the second pin 72 are respectively inserted into the plurality of through holes 31. The inner diameter of the plurality of through holes 31 corresponds to the outer diameter of the first pin 62 or the outer diameter of the second pin 72. Understandably, some through holes 31 are used for inserting the first pin 62, and the inner diameter of this through hole 31 is equal to or slightly smaller than the outer diameter of the first pin 62. Some through holes 31 are used for inserting the second pin 72, and the inner diameter of this through hole 31 is equal to or slightly smaller than the outer diameter of the second pin 72. This prevents external light from passing through the circuit board 30 and reaching the photosensitive part 71 of the photosensitive element PD1, thus preventing the photoelectric smoke detector 100 from falsely triggering an alarm due to external light.

[0045] Understandably, combined Figure 5As shown, the circuit board 30 provides a light-shielding effect for the second connection terminal 712 of the photosensitive part 71, avoiding the need to apply a light-shielding adhesive material to the second connection terminal 712 during the production and assembly process of the photoelectric smoke detector 100, which helps to simplify the production and assembly process of the photoelectric smoke detector 100.

[0046] In some implementations, combined Figure 4 and Figure 5 As shown, the base 20 has at least two cylindrical portions 21. The main lamp body 61 and the photosensitive part 71 are respectively inserted into the at least two cylindrical portions 21. Understandably, the main lamp body 61 and the cylindrical portion 21 are arranged in a one-to-one correspondence, with the main lamp body 61 inserted into the corresponding cylindrical portion 21. The photosensitive part 71 and the cylindrical portion 21 are arranged in a one-to-one correspondence, with the photosensitive part 71 inserted into the corresponding cylindrical portion 21.

[0047] Specifically, the depth of the cylindrical portion 21 is greater than the length of the main lamp body 61 and the length of the photosensitive portion 71. Understandably, since the first connecting end 612 of the main lamp body 61 abuts against the circuit board 30, the distance between the emitting end 611 of the main lamp body 61 and the cover plate 40 is greater than the minimum distance between the cylindrical portion 21 and the cover plate 40. As a result, the cylindrical portion 21 can play a certain collimating role on the detection light emitted by the emitting end 611, allowing the detection light to be more concentratedly directed towards the diffuse reflection area 41 of the cover plate 40, reducing the chance of the detection light being directly reflected to the photosensitive portion 71.

[0048] For example, combined Figure 5 As shown, the cylindrical portion 21 has openings at both ends. One end of the cylindrical portion 21 faces the cover plate 40, and the distance between this end and the cover plate 40 is less than the distance between the transmitting end 611 and the cover plate 40. The other end of the cylindrical portion 21 abuts against the circuit board 30, thereby preventing the detection light from leaking from the gap between the cylindrical portion 21 and the circuit board 30.

[0049] Understandably, since the second connection end 712 of the photosensitive part 71 abuts against the circuit board 30, the distance between the receiving end 711 of the photosensitive part 71 and the cover plate 40 is greater than the minimum distance between the cylindrical part 21 and the cover plate 40. Therefore, the cylindrical part 21 can partially constrict the detection light received by the receiving end 711, reducing the chance of the detection light being directly reflected to the photosensitive part 71, allowing the detection light to reach the photosensitive part 71 only through diffuse reflection. For example, when the photosensitive part 71 is inserted into the cylindrical part 21, the other end of the cylindrical part 21 abuts against the circuit board 30, thereby preventing external light from entering the cylindrical part 21 through the gap between the cylindrical part 21 and the circuit board 30, and preventing the photosensitive part 71 from receiving external light.

[0050] For example, the light source is a through-hole LED element.

[0051] Combination Figure 3 and Figure 6 As shown, at least one light source includes an LED1 for emitting infrared light and an LED2 for emitting blue light, thereby generating two detection light beams of different wavelengths. Specifically, LED1 emits infrared light with a wavelength around 940 nm to enhance the backscattering signal of small-diameter smoke particles. LED2 emits blue light with a wavelength around 470 nm to capture the forward scattering signal of large-diameter smoke particles.

[0052] In some implementations, combined Figure 3 and Figure 4 As shown, the distance between the light source LED1 and the photosensitive part 71 is greater than the distance between the light source LED2 and the photosensitive part PD1. The angle between the opposing directions of the light source LED1 and the photosensitive part 71 and the relative directions of the light source LED2 and the photosensitive part 71 is greater than zero, which allows a signal drop between the two wavelengths of detection light, which is beneficial for distinguishing the size of smoke particles from the smoke detection signal generated by the photosensitive part PD1.

[0053] In some implementations, combined Figure 6 and Figure 7 As shown, the photoelectric smoke detector 100 also includes a main control chip U1 disposed on the circuit board 30. The main control chip U1 has a first control pin and a second control pin. Light source elements LED1 and LED2 are light-emitting diodes. The anodes of light source elements LED1 and LED2 are electrically connected to a reference voltage point. The cathode of light source element LED1 is electrically connected to the first control pin. The cathode of light source element LED2 is electrically connected to the second control pin. Understandably, when the first control pin outputs a low level, light source element LED1 is turned on, emitting infrared light. When the second control pin outputs a low level, light source element LED2 is turned on, emitting blue light.

[0054] In some implementations, combined Figure 7 As shown, the main control chip U1 has a first detection pin and a second detection pin. A photosensitive element PD1 is electrically connected between the first and second detection pins. Understandably, the first and second detection pins apply a certain reverse voltage to the photosensitive element PD1. When the illumination of the photosensitive element PD1 by the detection light changes, the current through the photosensitive element PD1 changes accordingly, thereby enabling the photosensitive element PD1 to feed back a smoke detection signal to the main control chip U1.

[0055] In some implementations, combined Figure 6 and Figure 7As shown, the photoelectric smoke detector 100 includes a light-emitting diode (LED) 3. The main control chip U1 has a third control pin. The anode of the LED 3 is connected to a reference voltage point. The cathode of the LED 3 is connected to the third control pin of the main control chip U1. Specifically, when the main control chip U1 receives a supply voltage and the smoke value is below a threshold, the main control chip U1 uses the third control pin to alternately turn the LED 3 on and off to indicate that the photoelectric smoke detector 100 is operating normally. More specifically, the LED 3 emits green light when lit.

[0056] In some implementations, combined Figure 6 and Figure 7 As shown, the photoelectric smoke detector 100 includes a light-emitting diode (LED) 4. The main control chip U1 has a fourth control pin. The anode of the LED 4 is connected to a reference voltage point. The cathode of the LED 4 is connected to the fourth control pin of the main control chip U1. Specifically, when the smoke value exceeds a threshold, the main control chip U1 uses the fourth control pin to cause the LED 4 to alternately turn on and off, indicating that the photoelectric smoke detector 100 has detected smoke. More specifically, the LED 4 emits red light when lit. Understandably, the main control chip U1 internally generates a smoke value based on the smoke detection signal.

[0057] In some implementations, when the photoelectric smoke detector 100 malfunctions, the main control chip U1 uses its third and fourth control pins to cause LEDs 3 and 4 to alternately light up and off simultaneously. Specifically, when LEDs 3 and 4 are lit simultaneously, a yellow light is output.

[0058] In some implementations, combined Figure 6 As shown, the photoelectric smoke detector 100 also includes a power supply unit 81. The power supply unit 81 provides power to the main control chip U1. The power supply unit 81 also provides a reference voltage point. Exemplarily, the power supply unit 81 includes an energy storage device and a corresponding voltage regulation section.

[0059] In some implementations, combined Figure 6 As shown, the photoelectric smoke detector 100 also includes an electroacoustic unit 82. The main control chip U1 is electrically connected to the electroacoustic unit 82. When the smoke level exceeds a threshold, the main control chip U1 triggers the electroacoustic unit 82 to emit an alarm sound, enabling the user to promptly detect a fire. Exemplarily, the electroacoustic unit 82 is a buzzer or a speaker.

[0060] In some implementations, combined Figure 6As shown, the photoelectric smoke detector 100 also includes an input button 83. The input button 83 is electrically connected to the main control chip U1. Optionally, the input button 83 is used for testing or self-testing the photoelectric smoke detector 100 to confirm that the photoelectric smoke detector 100 is functioning normally.

[0061] The above embodiments are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A photoelectric smoke detector, characterized in that, include: Base; The circuit board faces the side of the base; A cover plate is disposed on the other side of the base; A labyrinth structure assembly is provided between the cover plate and the base; the labyrinth structure assembly defines a detection cavity in the circumferential direction; the cover plate has a diffuse reflection area on the side facing the base; At least one light source component; the light source component includes a main lamp body and a first pin, the main lamp body is inserted into the base, the main lamp body has a corresponding emitting end and a first connecting end, the first connecting end of the main lamp body abuts against the circuit board, and the first connecting end of the main lamp body is connected to the first pin; the first pin is inserted into the circuit board; the emitting end of the main lamp body is arranged opposite to the diffuse reflection area; and At least one photosensitive element; the photosensitive element includes a photosensitive part and a second pin, the photosensitive part being inserted into the base; the photosensitive part having an opposing receiving end and a second connecting end, the second connecting end of the photosensitive part abutting against the circuit board, the second connecting end of the photosensitive part being connected to a second pin; the second pin being inserted into the circuit board; the receiving end of the photosensitive part and the cover plate being disposed opposite to each other on the side facing the base.

2. The photoelectric smoke detector according to claim 1, characterized in that, The cover plate has several cone-shaped protrusions in the diffuse reflection area.

3. The photoelectric smoke detector according to claim 1, wherein The cover plate has several grooves in the diffuse reflection area, and the internal space of the grooves narrows along the depth direction.

4. The photoelectric smoke detector according to claim 1, wherein The circuit board has a plurality of through holes; the first pin and the second pin are respectively inserted into the plurality of through holes; the inner diameter of the plurality of through holes corresponds to the outer diameter of the first pin or the outer diameter of the second pin.

5. The photoelectric smoke detector according to claim 1, wherein The base has at least two cylindrical portions; the main lamp body and the photosensitive part are respectively inserted into the at least two cylindrical portions; the depth of the cylindrical portion is greater than the length of the main lamp body and the length of the photosensitive part.

6. The photoelectric smoke detector according to claim 1, wherein The at least one light source includes an LED1 for emitting infrared light and an LED2 for emitting blue light.

7. Photoelectric smoke detector according to claim 6, characterized in that The distance between the light source LED1 and the photosensitive part is greater than the distance between the light source LED2 and the photosensitive part; the angle between the opposite direction between the light source LED1 and the photosensitive part and the relative direction between the light source LED2 and the photosensitive part is greater than zero.

8. The photoelectric smoke detector according to claim 6, wherein It also includes a main control chip U1 disposed on the circuit board; the main control chip U1 is provided with a first control pin and a second control pin; the light source LED1 and the light source LED2 are light-emitting diodes; the anode of the light source LED1 and the anode of the light source LED2 are respectively electrically connected to a reference voltage point; the cathode of the light source LED1 is electrically connected to the first control pin; the cathode of the light source LED2 is electrically connected to the second control pin.

9. The photoelectric smoke detector according to claim 8, characterized in that, The main control chip U1 is provided with a first detection pin and a second detection pin; the photosensitive element is electrically connected between the first detection pin and the second detection pin.

10. The photoelectric smoke detector according to claim 8, wherein It also includes light-emitting diodes LED3 and LED4; the main control chip U1 is provided with a third control pin and a fourth control pin; the anodes of LED3 and LED4 are respectively electrically connected to a reference voltage point; the cathode of LED3 is electrically connected to the third control pin of the main control chip U1; the cathode of LED4 is electrically connected to the fourth control pin of the main control chip U1.

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