Smoke detector

A smoke detector includes a substrate, an optical detection module, a base and a top cover. The substrate has a ring shape region surrounding a central detection region, and a first block structure of the central detection region is protruded from the substrate and higher than an upper surface of the ring shape region. The optical detection module is disposed inside the central detection region. The base is disposed on the substrate and around the optical detection module. The base has a second block structure. The top cover is connected to the base. A lateral wall of the top cover is partly overlapped with the second block structure to form a guiding channel. The optical detection module analyzes variation of scattering parameters resulted from gaseous matter entering the top cover through the guiding channel for determining concentration of the gaseous matter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a smoke detector, and more particularly, to a smoke detector with preferred smoke conductivity and preferred gaseous permeability.

2. Description of the Prior Art

A conventional optical smoke detection device includes a circuit board, an optical detector and a housing. The optical detector is disposed on the circuit board. The housing is installed on the circuit board to cover the optical detector. The conventional optical smoke detection device forms a plurality of holes on the housing. External gaseous matter flows into and out of the housing through the holes. The optical detector projects an optical signal onto the gaseous matter inside the housing, and detects variation of scattering parameters resulted from the illuminated gaseous matter to determine concentration of the gaseous matter. However, a detection accuracy of the optical detector is affected because ambient light easily enters the housing through the holes. One solution forms the holes on an end of the housing distant from the optical detector, but gaseous permeability of the housing is decreased so that the conventional optical smoke detection device cannot provide preferred detection accuracy. Another solution disposes a shelter around the housing, and the gaseous permeability of the housing is also decreased to level down the detection accuracy of the optical detector. Therefore, design of a smoke detector with preferred smoke conductivity and preferred gaseous permeability and without interference from the ambient light is an important issue in the mechanical design industry.

SUMMARY OF THE INVENTION

The present invention provides a smoke detector with preferred smoke conductivity and preferred gaseous permeability for solving above drawbacks.

According to the claimed invention, a smoke detector includes a substrate, an optical detection module, a base and a top cover. The substrate has a ring shape region surrounding a central detection region, and a first block structure of the central detection region is protruded from the substrate and higher than an upper surface of the ring shape region. The optical detection module is disposed inside the central detection region. The base is disposed on the substrate and around the optical detection module. The base has a second block structure. The top cover is connected to the base. A lateral wall of the top cover is partly overlapped with the second block structure to form a guiding channel. The optical detection module analyzes variation of scattering parameters resulted from gaseous matter entering the top cover through the guiding channel for determining concentration of the gaseous matter.

According to the claimed invention, the top cover includes the lateral wall and a cover body connected to each other. At least one of the lateral wall and the cover body has an airtight property.

According to the claimed invention, a dimming structure is disposed on an inner surface of the top cover.

According to the claimed invention, a top of the first block structure is higher than an upper surface of the optical detection module.

According to the claimed invention, the top of the first block structure is overlapped with the lateral wall of the top cover.

According to the claimed invention, the central detection region includes a sunken structure whereon inside the optical detection module is disposed.

According to the claimed invention, the ring shape region includes a plurality of grooves, and a top end of each groove is lower than a top of the first block structure.

According to the claimed invention, a dimming structure is disposed on an inner surface of the substrate adjacent to the guiding channel.

According to the claimed invention, a radial dimension of the lateral wall is smaller than a radial dimension of the second block structure.

According to the claimed invention, the base is integrated with the top cover monolithically.

According to the claimed invention, the smoke detector further includes a plurality of connection ribs, two opposite ends of each of the plurality of connection ribs are respectively connected to an inner surface of the base and an outer surface of the top cover.

According to the claimed invention, the optical detection module further includes an optical emitter and an optical receiver, the optical emitter emits an illumination beam toward inner of the top cover, the optical receiver receives and analyses the variation of scattering parameters resulted from the illumination beam projected onto the gaseous matter.

The present invention can utilize the substrate, the base and the top cover to form the case of the smoke detector. The optical detection module can be disposed on the central detection region of the substrate and surrounded by the first block structure. The second block structure of the base can be overlapped with the lateral wall of the top cover; the ambient light can be only projected onto the ring shape region of the substrate due to foresaid overlapping of the second block structure and the lateral wall, to avoid the optical detection module from being illuminated by the ambient light. The first block structure of the substrate can be optionally overlapped with the lateral wall of the top cover, so as to effectively prevent the ambient light from being reflected from the ring shape region to the optical detection module. The top cover of the smoke detector can have the airtight property, and the connection rib can be connected between the base and the top cover to form the openings of the guiding channel. The external gaseous matter can enter the top cover through one part of the guiding channel, and exhaust from the top cover through another part of the guiding channel. The smoke detector of the present invention can have the preferred smoke conductivity and the preferred gaseous permeability due to design of the guiding channel, and can allow smooth passing of the gaseous matter by the large-size guiding channel for the preferred detection accuracy and the preferred detection sensitivity.

DETAILED DESCRIPTION

Please refer toFIG.1toFIG.5.FIG.1andFIG.2are exploded diagrams of a smoke detector10in different views according to an embodiment of the present invention.FIG.3is a diagram of the smoke detector10according to the embodiment of the present invention.FIG.4is a sectional view of the smoke detector10according to the embodiment of the present invention.FIG.5is a sectional view of the smoke detector10A according to another embodiment of the present invention. The smoke detector10can include an optical detection module12, a substrate14, a base16and a top cover18. The optical detection module12can analyze variation of scattering parameters to determine concentration of gaseous matter entering through the smoke detector10. The optical detection module12can be disposed inside a case of the smoke detector10. The case of the present invention can have advantages of high smoke conductivity and high gaseous permeability for effectively restraining interference of ambient light, so as to prevent a detection accuracy of the optical detection module12from being affected by variation of the ambient light.

The case can include a substrate14, a base16and a top cover18. The substrate14can have a ring shape region20and a central detection region22. The central detection region22is a place where on the optical detection module12is disposed. The central detection region22can be a hollow element; the smoke detector10may be installed on a circuit board (which is not shown in the figures), and the optical detection module12can pierce through the central detection region22to directly dispose on the circuit board. Besides, the central detection region22may be a solid element (which is not shown in the figures), and the optical detection module12can be directly disposed on the central detection region22. A type of the central detection region22is not limited to the embodiment shown inFIGS.1to4, and depends on a design demand. In addition, the central detection region22can have a sunken structure23, and the sunken structure23can be a hole of the hollow element or a center of the solid element. The optical detection module12can be disposed inside the sunken structure23.

The ring shape region20can be disposed around the central detection region22. The ring shape region20can have a plurality of grooves24, and each of the plurality of grooves24can surround the central detection region22as a concentric circle. A width, a depth and a shape of the groove24are not limited to the embodiment shown inFIGS.1to4, which depend on the design demand. The central detection region22can include a first block structure26protruded from the substrate14. A top of the first block structure26can be higher than an upper surface of the optical detection module12to avoid the interference of the ambient light. Besides, the top of the first block structure26can be higher than an upper surface201of the ring shape region20and a top end of the groove24. The top end of the groove24can be higher than the upper surface201of the ring shape region20, and a bottom end of the groove24can be lower than the upper surface201of the ring shape region20.

The base16can be disposed on the substrate14to surround and cover the optical detection module12, so as to provide a protection function and artistic decoration. The base16can have a second block structure28disposed on the substrate14as a ring. The second block structure28can be spaced from the top cover18. The smoke detector10can further include a plurality of connection ribs30. Two opposite ends of each connection rib30can be respectively connected to the inner surface of the base16(which means an inner lateral surface of the second block structure28) and an outer surface of the top cover18, and a plurality of openings can be formed between the substrate14and the base16. Therefore, the top cover18can be connected to the second block structure28via the connection ribs30. The smoke detector10can utilize the lateral wall32of the top cover18, the second block structure28of the base16, and the connection rib30to form a guiding channel composed of the plurality of openings. It should be mentioned that the lateral wall32can be partly overlapped with the second block structure28, as shown inFIG.4; a bottom of the lateral wall32can be lower than a top of the second block structure28, or the top cover18can be partly inserted into the second block structure28of the base16.

The top cover18can include a lateral wall32and a cover body34connected to each other. The lateral wall32and the cover body34can have an airtight property; the airtight property can be interpreted as the top cover18having no piercing holes and the top cover18being made by airtight material. The gaseous matter entering the smoke detector10through the guiding channel can be gathered inside the top cover18, and be detected by the optical detection module12and then exhausted from the smoke detector10through the guiding channel. The base16, the top cover18and the connection rib30can be independent elements assembled with each other in a detachable manner; besides, the base16may be integrated with the top cover18and the connection rib30monolithically. The optical detection module12can include an optical emitter36and an optical receiver38. Numbers and positions of the optical emitter36and the optical receiver38are not limited to the embodiment shown inFIG.4, and depend on the design demand. The optical emitter36can emit an illumination beam into the top cover18. The illumination beam can be projected onto the gaseous matter inside the top cover18to result in a scattering phenomenon. The optical receiver38can receive and analyze the variation of the scattering parameters resulted from the gaseous matter, so as to determine the concentration of the gaseous matter around the smoke detector10.

The lateral wall32of the top cover18can be partly overlapped with the second block structure28of the base16, for preventing the ambient light from directly projecting onto the optical receiver38, so that the smoke detector10can have the preferred detection accuracy of the optical detection module12. Overlap between the lateral wall32and the second block structure28can be interpreted as a planar normal vector of the lateral wall32is substantially parallel to a planar normal vector of the second block structure28, and the lateral wall32is partly located inside an inner space surrounded by the second block structure28. The top of the first block structure26can be optionally lower than the lateral wall32of the top cover18, which means the top of the first block structure26can be near to substrate14, and the gaseous matter can smoothly flow into the top cover18through the guiding channel between the base16and the top cover18and further between the substrate14and the top cover18, as the embodiment shown inFIG.4. Further, as the embodiment shown inFIG.5, the smoke detector10A can design that the top of the first block structure26A is optionally overlapped with the lateral wall32of the top cover18, overlap between the first block structure26A and the lateral wall32can be interpreted as a planar normal vector of the first block structure26A is substantially parallel to the planar normal vector of the lateral wall32, and the first block structure26A is partly located inside an inner space surrounded by the lateral wall32; in this embodiment, the top of the first block structure26A can be lengthened to partly insert into the top cover18, or the bottom of the lateral wall32can be lengthened to overlap with the first block structure26A, or the top of the first block structure26A and the bottom of the lateral wall32can be lengthened and overlapped. Structural design of the first block structure26A overlapped with the lateral wall32can be used to block a possible transmission path of the ambient light, so as to decrease the interference of the ambient light and increase the detection accuracy of the optical detection module12accordingly.

As the embodiments shown inFIG.4andFIG.5, a radial dimension of the lateral wall32can be smaller than a radial dimension of the second block structure28, and a radial dimension of the first block structure26can be smaller than the radial dimension of the lateral wall32. Difference between the foresaid radial dimensions can be a caliber of the guiding channel, and an actual value of the caliber can depend on the design demand, and a detailed description is omitted herein for simplicity. Moreover, the smoke detector10(or the smoke detector10A) can dispose a dimming structure40on a surface of the top cover18, and further dispose a dimming structure42on an inner surface (such as the ring shape region20) of the substrate14adjacent to the guiding channel. The dimming structure40and the dimming structure42can decrease reflection intensity of the illumination beam between the substrate14and the top cover18, so as to increase the detection sensitivity of the optical detection module12. The dimming structure40and the dimming structure42may be made by specific material or be composed of specific structural design. Features of the dimming structure40can be the same as or similar to features of the dimming structure42, and the detailed description is omitted herein for simplicity.

In conclusion, the present invention can utilize the substrate, the base and the top cover to form the case of the smoke detector. The optical detection module can be disposed on the central detection region of the substrate and surrounded by the first block structure. The second block structure of the base can be overlapped with the lateral wall of the top cover; the ambient light can be only projected onto the ring shape region of the substrate due to foresaid overlapping of the second block structure and the lateral wall, to avoid the optical detection module from being illuminated by the ambient light. The first block structure of the substrate can be optionally overlapped with the lateral wall of the top cover, so as to effectively prevent the ambient light from being reflected from the ring shape region to the optical detection module. The top cover of the smoke detector can have the airtight property, and the connection rib can be connected between the base and the top cover to form the openings of the guiding channel. The external gaseous matter can enter the top cover through one part of the guiding channel, and exhaust from the top cover through another part of the guiding channel. The smoke detector of the present invention can have the preferred smoke conductivity and the preferred gaseous permeability due to design of the guiding channel, and can allow smooth passing of the gaseous matter by the large-size guiding channel for the preferred detection accuracy and the preferred detection sensitivity.