CN111580177A - Light path structure of rainfall sensor - Google Patents
Light path structure of rainfall sensor Download PDFInfo
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- CN111580177A CN111580177A CN202010563847.6A CN202010563847A CN111580177A CN 111580177 A CN111580177 A CN 111580177A CN 202010563847 A CN202010563847 A CN 202010563847A CN 111580177 A CN111580177 A CN 111580177A
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- total reflection
- reflection surface
- glass
- end lens
- lens
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V8/00—Prospecting or detecting by optical means
- G01V8/10—Detecting, e.g. by using light barriers
- G01V8/12—Detecting, e.g. by using light barriers using one transmitter and one receiver
- G01V8/14—Detecting, e.g. by using light barriers using one transmitter and one receiver using reflectors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
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- General Physics & Mathematics (AREA)
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- General Life Sciences & Earth Sciences (AREA)
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- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses an optical path structure of a rainfall sensor, wherein the outer surface of glass is provided with a glass total reflection surface, the optical path structure comprises an emission source, an emission end lens, a plurality of double total reflection surface lenses, a receiving end lens and a receiving element, the double total reflection surface lenses are sequentially arranged, the emission source emits infrared signal light and emits the infrared signal light to the emission end lens, the infrared signal light forms parallel light which emits to the glass total reflection surface in the emission end lens, the parallel light sequentially passes through a plurality of optical path units and then enters the receiving end lens through the total reflection of the glass total reflection surface, the parallel light is gathered in the receiving end lens to form a receiving signal, and the receiving element receives the receiving signal. According to the optical path structure of the rainfall sensor, the number of the total internal reflection areas of the glass is increased by using the double-total-reflection-surface lens, so that the number and the total area of the induction areas are increased. And under the condition of the same induction parameters, the element cost can be saved.
Description
Technical Field
The invention belongs to the technical field of rainfall sensors, and particularly relates to a light path structure of a rainfall sensor.
Background
By the end of 2019, the number of automobiles in China reaches 2.6 hundred million, and is increased by 2122 ten thousand and 8.8 percent compared with the number of automobiles at the end of 2018. Along with the improvement of the quality of life of people, the demand for automobiles is continuously increased, and meanwhile, higher requirements are also placed on the functions of the automobiles, and the automobiles are particularly more intelligent.
At present, only a small number of medium-high grade vehicle types are provided with automatic wipers, and the main reason is that the sensors have certain technical barriers and are mastered by large automobile accessory enterprises at home and abroad, so that the selling price is high.
The rainfall sensor adopts an infrared LED as a signal light source, and utilizes a transmitting end lens to collimate and obliquely irradiate infrared signal light emitted by the LED into the front windshield of the automobile. When the obliquely incident signal light meets the angle requirement of the total reflection of the glass, the signal light can be reflected to the receiving end lens and focused and converged on the receiving element through the receiving end lens. When raindrops exist on the upper surface of the windshield, the total reflection condition is destroyed, the infrared signal light is directly emitted from the upper end of the windshield and does not return to the receiving element, the received signal is reduced, the raindrops on the windshield are judged, and the windscreen wiper is started, so that the function of the automatic windscreen wiper is realized.
As shown in fig. 1, a group of elements (emission source 1 and receiving element 2), a pair of lenses (lens 21 and lens 22), a silicone adhesive layer 31 and a glass 41 form an optical path whole, and a sensing region 5 (as shown in fig. 2) is formed on the upper surface of the windshield, and the sensing region directly determines the sensitivity of the sensor, which is one of the most important parameters of the sensor. Therefore, in order to increase the sensitivity, two-transmitter and two-receiver (comprising another set of elements: the emission source 3 and the receiving element 4, the lens 23 and the lens 24 as shown in fig. 1) or two-transmitter and three-receiver, or even one-transmitter and six-receiver are generally provided to increase the number of sensing regions and increase the area of the sensing regions. However, this requires a large number of components, which increases the cost of the sensor.
Disclosure of Invention
In order to solve the technical problems, the invention adopts the technical scheme that: an optical path structure of a rainfall sensor is arranged on the inner side of glass, the outer surface of the glass is a glass total reflection surface, the optical path structure comprises an emission source, an emission end lens, a plurality of double total reflection surface lenses, a receiving end lens and a receiving element, the double total reflection surface lenses respectively comprise a first total reflection surface and a second total reflection surface, the double total reflection surface lenses are sequentially arranged, the emission source emits infrared signal light and emits the infrared signal light to the emission end lens, the infrared signal light forms parallel light which emits to the glass total reflection surface in the emission end lens, the parallel light sequentially passes through a plurality of optical path units and then enters the receiving end lens through the total reflection of the glass total reflection surface, the parallel light is gathered in the receiving end lens to form a receiving signal, the receiving element receives the receiving signal, and each optical path unit sequentially comprises the total reflection of the glass total emission surface, the total reflection of the first, Total reflection of the second total reflection surface.
Preferably, the transmitting end lens, the double total reflection surface lens and the receiving end lens are respectively bonded on the inner surface of the glass through silica gel.
Preferably, in the above technical solution, the glass is a flat glass or a curved glass.
Preferably, the transmitting end lens, the double total reflection surface lens and the receiving end lens are all made of PC materials.
Preferably, in the above technical solution, an incident angle of the parallel light entering the first total reflection surface and an incident angle of the parallel light entering the second total reflection surface are respectively greater than a total reflection critical angle of the double total reflection surface lens.
Preferably, in the above technical solution, the first total reflection surface and the second total reflection surface are mirror surfaces.
The invention has the beneficial effects that: according to the optical path structure of the rainfall sensor, the number of the total internal reflection areas of the glass is increased by using the double-total-reflection-surface lens, so that the number and the total area of the induction areas are increased. And under the condition of the same induction parameters, the element cost can be saved.
Drawings
Fig. 1 is a schematic view of an optical path structure of a conventional rainfall sensor;
fig. 2 is a schematic view of an optical path of a conventional rainfall sensor;
fig. 3 is a schematic view of an optical path structure of the rainfall sensor of the present invention;
FIG. 4 is a schematic view of an optical path structure at another angle of the rainfall sensor of the present invention;
FIG. 5 is a schematic view of the optical path of the rain sensor of the present invention;
FIG. 6 is a schematic view of another optical path of the rain sensor of the present invention;
FIG. 7 is a schematic view of another optical path of the rain sensor of the present invention;
fig. 8 is a schematic view of another optical path structure of the rainfall sensor of the invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Example one
As shown in fig. 3-4, an optical path structure of a rain sensor is installed inside a glass 41, the outer surface of the glass 41 is a glass total reflection surface 42, the glass 41 is a plane glass, and the optical path structure comprises a transmitting source 1, a transmitting end lens 25, a double total reflection surface lens 27, a receiving end lens 26, and a receiving element 2. The transmitting end lens 25, the double total reflection surface lens 27 and the receiving end lens 26 are all made of PC material. The transmitting end lens 25, the double total reflection surface lens 27 and the receiving end lens 26 are respectively bonded on the inner surface of the glass 41 through silica gel, and the silica gel forms a silica gel bonding layer 31 on the inner surface of the glass 41. The double total reflection surface lens 27 comprises a first total reflection surface 28 and a second total reflection surface 29 respectively, the emission source 1 emits infrared signal light and emits the infrared signal light to the emission end lens 25, the infrared signal light forms parallel light 6 which emits to the total reflection surface of the glass 41 in the emission end lens 25, the incident angle of the parallel light 6 is larger than the total reflection critical angle of the glass 41, the parallel light is reflected and totally reflected in the total reflection surface 42 and then enters the double total reflection surface lens 27, the parallel light is totally reflected at the first total reflection surface 28 position and the second total reflection surface 29 position in sequence, then enters the glass 41 again, the total reflection surface 42 of the glass 41 is totally reflected and finally enters the receiving end lens 26, the receiving signal 7 is formed by gathering in the receiving end lens 26, and the receiving element 2 receives the receiving signal 7. Thus, the parallel light 6 forms two total reflection regions on the glass total reflection surface 42, and each region is defined as a sensing region 5. When raindrops exist on the outer surface of the glass 41 in the sensing area 5, the total reflection condition of the glass total reflection surface 42 is destroyed, the optical path of the parallel light 5 is destroyed, and the receiving signal 7 received by the receiving element 2 is changed, so that the rain and the rainfall are judged. The light ray directions of the parallel light 6 incident on the total reflection glass surface 42 twice can be parallel, as shown in fig. 5, or diverged by a certain angle, as shown in fig. 6, as long as the corresponding total reflection conditions are satisfied. However, it is desirable to avoid overlapping of the sensing regions, as shown in FIG. 7, which reduces the total area of the sensing regions.
Example two
As shown in fig. 8, an optical path structure of a rainfall sensor is installed inside a glass 41, and the outer surface of the glass 41 is a glass total reflection surface, and the optical path structure includes a transmitting source 1, a transmitting end lens 25, two double total reflection surface lenses 27, a receiving end lens 26, and a receiving element 2. The double total reflection surface lens 27 comprises a first total reflection surface 28 and a second total reflection surface 29 respectively. The emitting source 1 emits infrared signal light and emits the infrared signal light to the emitting end lens 25, the infrared signal light forms parallel light 6 which emits to the glass total reflection surface in the emitting end lens 25, the incident angle of the parallel light 6 is larger than the total reflection critical angle of the glass 41, the parallel light is reflected and totally reflected on the total reflection surface, then enters the first double total reflection surface lens 27, the total reflection occurs in the first total reflection surface 28 position and the second total reflection surface 29 position of the first double total reflection surface lens 27 in sequence, then enters the glass 41 again, the total reflection occurs on the glass total reflection surface, the infrared signal light enters the second double total reflection surface lens 27, the total reflection occurs in the first total reflection surface 28 position and the second total reflection surface 29 position of the second double total reflection surface lens 27 in sequence, then enters the glass 41 again, and the total reflection occurs on the glass 41 total reflection surface. Finally, the received signal enters the receiving end lens 26, is collected in the receiving end lens 26 to form the received signal 7, and the receiving element 2 receives the received signal 7. Thus the parallel light 6 forms 3 sensing regions 5 on the total reflection surface of the glass. The incident angle of the parallel light 6 at both the first total reflection surface 28 and the second total reflection surface 29 must satisfy the total reflection condition. Therefore, the emission source 1, the emission end lens 25, the double total reflection surface lens 27, the receiving end lens 26 and the receiving element 2 are installed on the inner side of the glass 41 within the designed angle range. While taking into account the refractive index of the silicone adhesive layer 31. If the installation angle is limited, and the first total reflection surface 28 and the second total reflection surface 29 of the double total reflection surface lens 27 cannot form a total reflection condition, a mirror surface treatment can be electroplated on the outer sides of the first total reflection surface 28 and the second total reflection surface 29, so that the first total reflection surface 28 and the second total reflection surface 29 form a mirror surface reflection, and the above-mentioned optical path structure requirement is also met. However, the utilization of specular reflection increases the device processing cost compared to a total reflection effect that is entirely dependent on the structure and material of the double total reflection surface lens 27.
It should be noted that the technical features of the emission source, the receiving element, etc. related to the present patent application should be regarded as the prior art, and other components of the rainfall sensor, and the specific structure, the operation principle, and the control mode and the spatial arrangement mode that may be related to these technical features are all conventional in the art, and should not be regarded as the invention point of the present patent, and the present patent is not further specifically described in detail.
Having described preferred embodiments of the present invention in detail, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. The light path structure of the rainfall sensor is arranged on the inner side of glass, the outer surface of the glass is set as a glass total reflection surface, the light path structure comprises an emission source, an emission end lens, a plurality of double total reflection surface lenses, a receiving end lens and a receiving element, the double total reflection surface lenses respectively comprise a first total reflection surface and a second total reflection surface, the double total reflection surface lenses are sequentially arranged, the emission source emits infrared signal light and emits the infrared signal light to the emission end lens, the infrared signal light forms parallel light which emits to the glass total reflection surface in the emission end lens, the parallel light sequentially passes through a plurality of light path units and then enters the receiving end lens through the total reflection of the glass total reflection surface, the parallel light is collected in the receiving end lens to form a receiving signal, the receiving element receives the receiving signal, and each light path unit sequentially comprises the total reflection of the glass total emission surface, The total reflection of the first total reflection surface and the total reflection of the second total reflection surface.
2. The optical path structure of a rain sensor according to claim 1, wherein the transmitting end lens, the double total reflection surface lens and the receiving end lens are respectively bonded to an inner surface of the glass by silicone.
3. The optical path structure of a rainfall sensor of claim 1, wherein the glass is a flat glass or a curved glass.
4. The optical path structure of a rainfall sensor of claim 1 wherein the transmitting end lens, the double total reflection surface lens and the receiving end lens are all made of PC material.
5. The optical path structure of a rainfall sensor of claim 4, wherein an incident angle of the parallel light entering the first total reflection surface and an incident angle of the parallel light entering the second total reflection surface are respectively larger than a total reflection critical angle of the double total reflection surface lens.
6. The optical path structure of a rainfall sensor of claim 4, wherein the first total reflection surface and the second total reflection surface are mirror surfaces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010563847.6A CN111580177A (en) | 2020-06-19 | 2020-06-19 | Light path structure of rainfall sensor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010563847.6A CN111580177A (en) | 2020-06-19 | 2020-06-19 | Light path structure of rainfall sensor |
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| CN111580177A true CN111580177A (en) | 2020-08-25 |
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| CN202010563847.6A Pending CN111580177A (en) | 2020-06-19 | 2020-06-19 | Light path structure of rainfall sensor |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2781576A1 (en) * | 1998-07-27 | 2000-01-28 | Valeo Systemes Dessuyage | Optical attachment to vehicle windscreen for detecting dirt or stains on surface: comprises transmitter and receiver, parabolic lenses and reflector to produce parallel light paths with internal reflections |
| CN101852647A (en) * | 2009-03-31 | 2010-10-06 | 玉晶光电股份有限公司 | Wiper Sensing Optical System |
| CN212569180U (en) * | 2020-06-19 | 2021-02-19 | 嘉兴朗思光学科技有限公司 | Light path structure of rainfall sensor |
-
2020
- 2020-06-19 CN CN202010563847.6A patent/CN111580177A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2781576A1 (en) * | 1998-07-27 | 2000-01-28 | Valeo Systemes Dessuyage | Optical attachment to vehicle windscreen for detecting dirt or stains on surface: comprises transmitter and receiver, parabolic lenses and reflector to produce parallel light paths with internal reflections |
| CN101852647A (en) * | 2009-03-31 | 2010-10-06 | 玉晶光电股份有限公司 | Wiper Sensing Optical System |
| CN212569180U (en) * | 2020-06-19 | 2021-02-19 | 嘉兴朗思光学科技有限公司 | Light path structure of rainfall sensor |
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