Optical path structural components

Abstract

This invention relates to the field of gas sensor technology, and more particularly to an optical path structure. The optical path structure provided by this invention includes a PCB board with a light emitting unit and a light receiving unit. A reflective dielectric layer is provided on the surface of the PCB board to reflect the light emitted by the light emitting unit. The optical path structure also includes a light reflecting element, which is attached to the PCB board and completely covers the reflective dielectric layer, the light emitting unit, and the light receiving unit. The light reflecting element has internal grooves formed as a light path. After the light emitting unit emits light, it is reflected by the reflective dielectric layer into the grooves of the light reflecting element and then transmitted along the light path formed by the grooves to the light receiving unit. This invention uses a reflective dielectric layer as the lower reflector and a light reflecting element manufactured by stamping as the upper reflector, reducing the cost of the entire optical path structure by eliminating an expensive reflective component; furthermore, the stamping process is also less expensive.

Description

Technical Field

[0001] This invention relates to the field of gas sensor technology, and more particularly to an optical path structure. Background Technology

[0002] Gas sensors based on the principle of non-dispersive infrared absorption detection require an infrared light source to emit light. This light travels a certain distance along a channel filled with the target gas before being received by the detector. Within this predetermined distance, the target gas absorbs sufficient amounts of infrared light of a specific wavelength to generate a sufficient signal strength. Simultaneously, this light propagation path cannot be open, otherwise it will be interfered with by infrared radiation from the external environment. Therefore, the optical path is typically designed within a tubular structure with a highly reflective inner surface. The longer the optical path, the more the target gas absorbs infrared light of a specific wavelength, and the higher the detector's sensitivity. However, this contradicts the trend towards system miniaturization. Therefore, in practical products, many employ spiral, zigzag, or U-shaped optical path channels to extend the optical path length within a given volume.

[0003] The common structure currently on the market is as follows: Transmitting and receiving components are mounted on a PCB. A bottom metal component is mounted on the PCB, its surface serving as the lower reflective surface of the optical path channel. Another top metal component with internal slots is used to form the side and top walls of the optical path channel. The top metal component is then placed upside down on top of the bottom metal component, and holes are provided on the top metal component to allow gas to diffuse in. This traditional structure uses two components, increasing processing and material costs. These components are generally machined metal or electroplated injection molded parts, which also increases costs. Summary of the Invention

[0004] To address the technical problem of high material and processing costs associated with current sensors that use two structural components, this application provides an optical path structural component.

[0005] This application provides an optical path structure, including a PCB board, on which a light emitting unit and a light receiving unit are provided.

[0006] The PCB board has a reflective dielectric layer on its surface to reflect the light emitted by the light emitting unit;

[0007] The optical path structure also includes a light reflecting element, which is attached to the PCB board and completely covers the reflective medium layer, the light emitting unit, and the light receiving unit;

[0008] The light reflecting element has grooves inside as light paths. After the light emitting unit emits light, it is reflected by the reflective medium layer into the grooves of the light reflecting element and transmitted along the light path formed by the grooves to the light receiving unit, where the light is received.

[0009] In one feasible implementation, the groove is formed by connecting a transmission path and a reception path, the initial end of the transmission path being adapted to the size of the light emitting unit, and the end of the reception path being adapted to the size of the light receiving unit.

[0010] In one feasible implementation, the transmitting path and the receiving path are separated by a central channel, and a through slot is formed at the center of the central channel. The through slot communicates with the outside, allowing gas to enter the interior of the optical path structure through the through slot, so that light can be transmitted along the optical path filled with target gas.

[0011] In one feasible implementation, the two sides of the through slot are comb-shaped structures. After the gas enters the interior of the optical path structure, it passes through the comb-shaped structures and diffuses evenly into the transmitting path and the receiving path.

[0012] In one feasible implementation, the light-reflecting element is manufactured by a stamping process.

[0013] In one feasible implementation, the reflective medium layer is a metal sheet, a mirror, a reflective film, or a reflective coating.

[0014] In one feasible implementation, when the reflective medium layer is a metal sheet, the surface of the metal sheet is its original color, or it is electroplated or painted.

[0015] In one feasible implementation, the reflective dielectric layer is a copper foil.

[0016] In one feasible implementation, the reflective medium layer is a gold-plated copper foil.

[0017] The present invention also provides a packaged sensor, optical device or infrared device using the above-described optical path structure.

[0018] The optical path structure provided by this invention has the following beneficial effects:

[0019] (1) Using a layer of reflective medium as the lower reflector and a light-reflecting element processed by stamping as the upper reflector not only reduces the cost of an expensive reflective structure in the entire optical path structure, but also lowers the cost of the stamping process.

[0020] (2) The two sides of the middle channel of the light reflecting element are comb-shaped structures, so that after the gas enters the interior of the optical path structure, it can pass through the comb-shaped structure and diffuse quickly and evenly into the emission path and the receiving path on both sides, so that the gas can absorb enough light and generate sufficient signal strength. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a PCB board and its surface reflective dielectric layer;

[0023] Figure 2 This is a schematic diagram of the internal structure of a light-reflecting element;

[0024] Figure 3 This is an external schematic diagram of a light-reflecting element.

[0025] Explanation of reference numerals in the attached figures

[0026] 1-PCB board, 2-light emitting unit, 3-light receiving unit, 4-reflective dielectric layer, 5-light reflecting element, 6-emitting path, 7-receiving path, 8-center channel, 9-through slot. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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.

[0028] Example 1:

[0029] This invention provides an optical path structure, including a PCB board 1, on which a light emitting unit 2 and a light receiving unit 3 are disposed; a reflective dielectric layer 4 is attached to the surface of the PCB board 1, which is capable of reflecting the light emitted by the light emitting unit 2, such as... Figure 1 As shown.

[0030] In addition, the optical path structure also includes a light reflecting element 5, which can be manufactured by stamping. Its internal structure is as follows: Figure 2As shown, the light reflecting element 5 has a groove inside as a light path. The groove is formed by the connection of the emission path 6 and the receiving path 7. The initial end of the emission path 6 is adapted to the light emitting unit 2, and the end of the receiving path 7 is adapted to the light receiving unit 3. The light reflecting element 5 is directly attached to the PCB board 1, completely covering the reflective dielectric layer 4, the light emitting unit 2, and the light receiving unit 3. After the light emitting unit 2 emits light, it is reflected by the reflective dielectric layer 4 to the groove of the light reflecting element 5, and then transmitted along the light path formed by the groove to the light receiving unit 3, where the light is received.

[0031] like Figure 2 As shown, the transmitting path 6 and the receiving path 7 are separated by a central channel 8, and a through slot 9 is formed in the center of the central channel 8. Figure 3 The diagram shows the external appearance of the light reflecting element 5. The through-slot 9 connects to the outside, allowing gas to enter the optical path structure and transmit light along the path filled with the target gas. Please continue reading. Figure 2 The two sides of the through slot 9 are comb-shaped structures, which allow the gas to diffuse evenly into the transmitting path 6 and the receiving path 7 after entering the optical path structure.

[0032] Example 2:

[0033] Based on Example 1, such as Figure 1 As shown, the reflective medium layer 4 can be any material with reflective properties, such as metal plate, mirror, reflective film, or a layer of reflective coating on the surface of PCB board 1, etc., all of which can be used as the lower reflector of the optical path structure. When using metal plate as the lower reflector, the original color surface of the metal plate can be used, or the surface of the metal plate can be electroplated or painted, depending on the actual required reflection intensity.

[0034] Example 3:

[0035] This embodiment provides a specific material that can be used as a lower reflector. The reflective dielectric layer 4 is selected as an exposed copper foil without solder mask coverage and with good reflective properties. The copper foil of appropriate size is directly attached to the PCB board 1 to serve as the lower reflector of the optical path structure. Of course, in order to obtain a better reflection effect, gold-plated copper foil can be used, which has stronger reflective properties.

[0036] Those skilled in the art should be able to select a suitable material as the lower reflector based on the actual reflective performance requirements and the cost of the reflective medium layer 4.

[0037] This invention uses a reflective dielectric layer directly attached to the PCB board as the lower reflector of the optical path structure, and then directly attaches the light-reflecting element to the reflective dielectric layer as the upper reflector. This reduces the cost of the entire optical path structure by eliminating an expensive reflective component. Furthermore, the reflective dielectric layer can be made of readily available metal sheet, processed into the light-reflecting element through a stamping process, further reducing costs. The light-reflecting element has comb-like structures on both sides of the through-slot, allowing gas entering the light-reflecting element to diffuse evenly and rapidly into the emission and reception paths, ensuring sufficient absorption of light by the gas.

[0038] The optical path structure of the present invention can be applied to various packaged sensors, optical devices or infrared devices. All devices that include the optical path structure of the present invention should fall within the protection scope of this application.

[0039] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical path structure, comprising a PCB board, wherein the PCB board is provided with a light emitting unit and a light receiving unit, characterized in that, The PCB board has a reflective dielectric layer on its surface to reflect the light emitted by the light emitting unit; The optical path structure also includes a light reflecting element, which is attached to the PCB board and completely covers the reflective medium layer, the light emitting unit, and the light receiving unit; The light reflecting element has grooves inside as light paths. After the light emitting unit emits light, it is reflected by the reflective medium layer into the grooves of the light reflecting element and transmitted along the light path formed by the grooves to the light receiving unit, where the light is received. The groove is formed by connecting a transmission path and a reception path. The initial end of the transmission path is adapted to the size of the light emitting unit, and the end of the reception path is adapted to the size of the light receiving unit. The transmitting path and the receiving path are separated by a central channel. A through slot is opened at the center of the central channel. The through slot is connected to the outside, so that gas can enter the optical path structure through the through slot and the light can be transmitted along the optical path filled with the target gas. The two sides of the through slot are comb-shaped structures. After the gas enters the optical path structure, it passes through the comb-shaped structures and diffuses evenly into the transmitting path and the receiving path. The light-reflecting element is manufactured by a stamping process.

2. The optical path structure according to claim 1, characterized in that, The reflective medium layer is a metal plate, a mirror, a reflective film, or a reflective coating.

3. The optical path structure according to claim 2, characterized in that, When the reflective medium layer is a metal sheet, the surface of the metal sheet is its original color, or it is electroplated or painted.

4. The optical path structure according to claim 1, characterized in that, The reflective medium layer is copper foil.

5. The optical path structure according to claim 1, characterized in that, The reflective medium layer is gold-plated copper foil.

6. A packaged sensor, optical device, or infrared device, characterized in that, Use the optical path structure as described in any one of claims 1-5.

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