CN111443402B - Rain and light sensor for vehicles - Google Patents

Abstract

The invention relates to the field of sensors, in particular to a vehicle rainfall illumination sensor, which comprises an optical path component plate (1), a circuit board (8), a shell (9) and a silica gel film (10); a light emitter component and a light receiver component are fixedly arranged on the circuit board (8); an emission lens component, a receiving lens component, a forward light lens (20) and a top light lens (21) are fixedly arranged on the light path component plate (1); the first emission lens (12), the second emission lens (13), the third emission lens (14) and the fourth emission lens (15) are all emission convex lenses with the same structure; the emission convex lens comprises an emission main lens (121), a compensation lens (122), a left wing-shaped lens (123) and a right wing-shaped lens (124) which are respectively identical in lens focusing point positions. The invention has small volume, high light utilization rate, large rain sensing area and low material and process requirements.

Description

Rain and light sensor for vehicles

Technical Field

The invention relates to the field of sensors, and in particular to a vehicle-used rainfall and light sensor.

Background Art

As the popularity of household vehicles in my country increases, people's demand for safety and comfort while driving is gradually increasing. However, the driver's manual operation of the vehicle's windshield wipers on rainy days distracts the driver's driving attention, bringing serious safety hazards, and resulting in frequent traffic accidents. The automatic wiper system automatically controls the wiper to wipe the rain according to the rainfall conditions, which can completely solve the above-mentioned hidden dangers. Therefore, the automatic wiper system, which was previously only used in high-end vehicles, is gradually becoming popular in mid- and low-end vehicles. As the sensing and collection unit of the automatic wiper system, the rain sensor is currently mainly imported from abroad due to technical limitations, and there is an urgent need to develop a domestic alternative product with excellent performance.

At present, the optical rainfall and light sensor is more concerned. It is realized by the total reflection theory of light. Its light guide lens design is one of the important technical factors affecting the sensor's light utilization rate and rain sensing area. At present, the light guide lenses of optical rainfall and light sensors are mainly in the form of Fresnel lens and ordinary convex lens. The Fresnel lens type rainfall and light sensor is easier to miniaturize and has a relatively large rain sensing area, but the disadvantage is that the lens has high requirements for material selection and processing technology, and the production cost is relatively high; the convex lens type rainfall and light sensor of the same volume has relatively lower requirements for materials and processing technology, is easier to produce by processing companies, and has a lower production cost, but is limited by the space of the miniaturized rainfall and light sensor, so the light utilization rate and rain sensing area are slightly lower than the Fresnel lens type rainfall and light sensor.

Summary of the invention

The present invention aims to overcome the shortcomings of the prior art and provide a vehicle-use rainfall light sensor with small volume, high light utilization rate, large rain sensing area and low material and process requirements.

To solve the above technical problems, the present invention is achieved as follows:

A vehicle rain and light sensor comprises an optical path component board, a circuit board, a housing and a silicone film; the circuit board is placed in the housing; the optical path component board is fixedly connected to the housing; one side of the silicone film is adhered to the outer side of the optical path component board, and the other side is adhered to the front windshield of the vehicle;

A light transmitter component and a light receiver component are fixedly arranged on the circuit board; the light transmitter component includes a first light transmitter, a second light transmitter, a third light transmitter and a fourth light transmitter; the light receiver component includes a first light receiver and a second light receiver;

An emitting lens assembly, a receiving lens assembly, a forward light lens and a top light lens are fixedly provided on the optical path assembly plate; the emitting lens assembly comprises a first emitting lens, a second emitting lens, a third emitting lens and a fourth emitting lens; the receiving lens assembly comprises a first receiving lens, a second receiving lens, a third receiving lens and a fourth receiving lens;

The first emitting lens, the second emitting lens, the third emitting lens and the fourth emitting lens are all emitting convex lenses with the same structure; the emitting convex lens comprises an emitting main lens, a compensating lens, a left wing-shaped lens and a right wing-shaped lens with the same lens focusing point positions; the emitting main lens and the compensating lens are opposite to each other; the left wing-shaped lens is located on the left side of the emitting main lens; and the right wing-shaped lens is located on the right side of the emitting main lens;

The transmitting main lens has a convex lens surface for receiving light emitted by the light emitter assembly;

The compensating lens has two light guiding surfaces, namely a focusing surface and a reflecting surface;

The left wing type lens has two light guiding surfaces, namely a left wing focusing surface and a left wing reflecting surface;

The right wing type lens has two light guiding surfaces, namely a right wing focusing surface and a right wing reflecting surface;

The light focusing points of the transmitting lens assembly correspond one-to-one to the position of the light transmitting assembly; the light focusing points of the receiving lens assembly correspond to the position of the light receiving assembly, and the focused light of the two receiving lenses in the receiving lens assembly is received by a light receiver in the light receiving assembly; the transmitting lens assembly and the receiving lens assembly form a conjugate relationship respectively.

As a preferred solution, the incident angles of parallel light rays emitted from the main emitting lens, the compensating lens, the left wing lens, and the right wing lens to the front windshield are the same.

Furthermore, in the present invention, if the critical angle for total reflection of light without rain is θ ₁ and the critical angle for total reflection of light with rain is θ 2 , the incident angle θ of the parallel light emitted from the emission lens assembly to the front windshield satisfies θ ₁ <θ<θ ₂ .

Furthermore, in the present invention, a light isolation plate is fixedly provided between the forward light lens and the top light lens.

Furthermore, the present invention has a locking buckle fixedly provided on the optical path component plate; the locking buckle comprises a buckle and a pressing column; and a buckle column is fixedly provided on the housing at a position corresponding to the buckle (231).

When light is incident from a denser medium to a less dense medium, total reflection will occur if the incident angle of the light is greater than the critical angle. The invention determines whether there is rain and the amount of rain according to the strength of the received total reflection light signal, outputs a control signal, and controls the wiper to automatically wipe the rain.

Compared with the prior art, the present invention has the following characteristics:

1. The design of the auxiliary lens and the wing-shaped lens takes into account the emission angle and direction of the light source, collects the light that does not enter the main emission lens, and increases the light utilization rate.

2. The confocal design of the light receiving lens enables one light receiver to receive signals from more than one area, increasing the rain sensing area.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. The protection scope of the present invention is not limited to the following description.

Fig. 1 is an appearance diagram of the present invention;

FIG2 is an exploded view of the overall structure of the present invention;

FIG3 is a structural diagram of an optical path component of the present invention;

FIG4 is a structural diagram of an emission lens of the present invention;

FIG5 is a diagram showing the positions of optical components on a circuit board according to the present invention;

FIG6 is a schematic diagram of light emission according to the present invention;

FIG7 is a schematic diagram of light receiving according to the present invention;

FIG8 is a structural diagram of the locking buckle of the present invention;

Fig. 9 is a diagram of the housing of the present invention;

FIG. 10 is a schematic diagram showing the principle of the present invention.

In the figure: 1, optical path component board; 2, first light emitter; 3, second light emitter; 4, third light emitter; 5, fourth light emitter; 6, first light receiver; 7, second light receiver; 8, circuit board; 9, housing; 10, silicone film; 11, spring buckle; 12, first emitting lens; 13, second emitting lens; 14, third emitting lens; 15, fourth emitting lens; 16, first receiving lens; 17, second receiving lens; 18, third receiving lens; 19, fourth receiving lens; 20, forward light lens; 21, top light lens; 22, light isolation plate; 23, locking buckle; 24, front windshield of the car; 91. Limiting column; 92. Buckle column; 93. Buckle groove; 231. Buckle; 232. Pressing column; 121. Emitting main lens; 122. Compensating lens; 123. Left wing lens; 124. Right wing lens; 1211. Convex lens surface; 1221. Focusing surface; 1222. Reflecting surface; 1231. Left wing focusing surface; 1232. Left wing reflecting surface; 1241. Right wing focusing surface; 1242. Right wing reflecting surface.

DETAILED DESCRIPTION

As shown in the figure, the vehicle rain light sensor is realized according to the total reflection principle of light, and comprises an optical path component board 1, a circuit board 8, a housing 9 and a silicone film 10; the circuit board 8 is placed in the housing 9; the optical path component board 1 is fixedly connected to the housing 9; one side of the silicone film 10 is adhered to the outer side of the optical path component board 1, and the other side is adhered to the front windshield of the car;

A light transmitter component and a light receiver component are fixedly arranged on the circuit board 8; the light transmitter component includes a first light transmitter 2, a second light transmitter 3, a third light transmitter 4 and a fourth light transmitter 5; the light receiver component includes a first light receiver 6 and a second light receiver 7;

An emitting lens assembly, a receiving lens assembly, a forward light lens 20 and a top light lens 21 are fixedly provided on the optical path assembly plate 1; the emitting lens assembly comprises a first emitting lens 12, a second emitting lens 13, a third emitting lens 14 and a fourth emitting lens 15; the receiving lens assembly comprises a first receiving lens 16, a second receiving lens 17, a third receiving lens 18 and a fourth receiving lens 19;

The first emitting lens 12, the second emitting lens 13, the third emitting lens 14 and the fourth emitting lens 15 are all emitting convex lenses with the same structure; the emitting convex lenses include an emitting main lens 121, a compensating lens 122, a left wing-shaped lens 123 and a right wing-shaped lens 124 with the same lens focusing point positions; the emitting main lens 121 and the compensating lens 122 are opposite to each other; the left wing-shaped lens 123 is located on the left side of the emitting main lens 121; and the right wing-shaped lens 124 is located on the right side of the emitting main lens 121;

The transmitting main lens 121 has a convex lens surface 1211 for receiving light emitted by the light emitter assembly;

The compensation lens 122 has two light guiding surfaces, namely a focusing surface 1221 and a reflecting surface 1222;

The left wing lens 123 has two light guiding surfaces, namely a left wing focusing surface 1231 and a left wing reflecting surface 1232;

The right wing lens 124 has two light guiding surfaces, namely a right wing focusing surface 1241 and a right wing reflecting surface 1242;

The light focusing points of the transmitting lens assembly correspond one-to-one to the position of the light transmitter assembly; the light focusing points of the receiving lens assembly correspond to the position of the light receiver assembly, and the focused light of the two receiving lenses is received by a common light receiver; the transmitting lens assembly and the receiving lens assembly form a conjugate relationship respectively.

The incident angles of parallel light rays emitted from the main emission lens 121, the compensation lens 122, the left wing lens 123, and the right wing lens 124 to the front windshield are the same.

In the present invention, if the critical angle for total reflection of light in rainless state is θ ₁ and the critical angle for total reflection of light in rainy state is θ 2 , the incident angle θ of the parallel light emitted from the emission lens assembly to the front windshield satisfies θ ₁ <θ<θ ₂ .

In the present invention, a light isolation plate 22 is fixedly disposed between the forward light lens 20 and the top light lens 21 .

In the present invention, a locking buckle 23 is fixedly provided on the optical path component plate 1 ; the locking buckle 23 includes a buckle 231 and a pressing column 232 ; and a buckle column 92 is fixedly provided on the housing 9 at a position corresponding to the buckle 231 .

In specific design, the present invention is mainly composed of an optical path component board 1, a first light emitter 2, a second light emitter 3, a third light emitter 4, a fourth light emitter 5, a first light receiver 6, a second light receiver 7, a circuit board 8, a shell 9, a silicone film 10 and a spring buckle 11. The first light emitter 2, the second light emitter 3, the third light emitter 4, the fourth light emitter 5, the first light receiver 6 and the second light receiver 7 are located on the circuit board 8; the circuit board 8 is placed in the shell 9; the shell 9 is tightly connected with the optical path component board 1 to form the appearance of the rain light sensor; one side of the silicone film 10 is pasted on the outside of the optical path component board 1, and the other side is pasted on the front windshield of the car; the spring buckle 11 is connected with the reserved buckle of the front windshield of the car to fasten and install the rain light sensor.

The optical path component plate 1 is provided with a first emitting lens 12, a second emitting lens 13, a third emitting lens 14, a fourth emitting lens 15, a first receiving lens 16, a second receiving lens 17, a third receiving lens 18, a fourth receiving lens 19, a forward light lens 20, a top light lens 21, a light isolation plate 22 and a locking buckle 23.

The first emitting lens 12, the second emitting lens 13, the third emitting lens 14 and the fourth emitting lens 15 have the same structure, and are composed of four convex lenses with different focal lengths, diameters and lengths, namely, an emitting main lens 121, a compensating lens 122, a left wing-shaped lens 123 and a right wing-shaped lens 124, and the focusing points of the four lenses are at the same position. The emitting main lens 121 and the compensating lens 122 are located opposite to each other, the left wing-shaped lens 123 is located on the left side of the emitting main lens 121, and the right wing-shaped lens 124 is located on the right side of the emitting main lens 121.

The emitting main lens 121 has a light guiding surface, which is a convex lens surface 1211 that plays a focusing role. It is the main focusing light guiding lens, and has the largest range of receiving light emitted by the light emitter component. The light is refracted by the emitting main lens 121 into parallel light and is emitted to the front windshield with a set angle θ as the incident angle.

The compensation lens 122 has two light guiding surfaces, namely a focusing surface 1221 and a reflecting surface 1222. The focusing surface 1221 is a refractive surface for the emitted light, refracting the emitted light into parallel light and then projecting it toward the reflecting surface 1222. The reflecting surface 1222 is a total reflection surface for the parallel light formed by the focusing surface 1221, and totally reflects the parallel light and projects it toward the front windshield. The parallel light after total reflection by the compensation lens 122 takes the set angle θ as the incident angle, and is directly projected from the inside of the lens through the silicone film toward the front windshield without entering the air.

The left wing lens 123 has two light guiding surfaces, namely the left wing focusing surface 1231 and the left wing reflecting surface 1232. The left wing focusing surface 1231 is a refractive surface for the emitted light, refracting the emitted light into parallel light and then projecting it to the left wing reflecting surface 1232. The left wing reflecting surface 1232 is a total reflection surface for the parallel light formed by the left wing focusing surface 1231, and totally reflects the parallel light and projects it to the front windshield. The parallel light after total reflection of the left wing lens 123 takes the set angle θ as the incident angle, and is directly projected from the inside of the lens through the silicone film to the front windshield without entering the air.

The right wing lens 124 has two light guiding surfaces, namely the right wing focusing surface 1241 and the right wing reflecting surface 1242. The right wing focusing surface 1241 is a refractive surface for the emitted light, refracting the emitted light into parallel light and then projecting it to the right wing reflecting surface 1242. The right wing reflecting surface 1242 is a total reflection surface for the parallel light formed by the right wing focusing surface 1241, and totally reflects the parallel light and projects it to the front windshield. The parallel light after total reflection of the right wing lens 124 takes the set angle θ as the incident angle, and is directly projected from the inside of the lens through the silicone film to the front windshield without entering the air.

The incident angles θ of the parallel light rays emitted from the main emission lens 121 , the compensation lens 122 , the left wing lens 123 , and the right wing lens 124 to the front windshield are the same.

The incident angle design of the parallel light emitted to the front windshield through the first emitting lens 12, the second emitting lens 13, the third emitting lens 14 and the fourth emitting lens 15 meets the angle requirement that the front windshield will produce total reflection when there is no rain, and also meets the angle requirement that the front windshield cannot produce total reflection when there is rain. If the critical angle for total reflection of light when there is no rain is θ1, and the critical angle for total reflection of light when there is rain is θ2, then the design value θ of the incident angle of light satisfies θ1<θ<θ2.

The light focusing points of the first emitting lens 12, the second emitting lens 13, the third emitting lens 14 and the fourth emitting lens 15 correspond to the positions of the first light emitter 2, the second light emitter 3, the third light emitter 4 and the fourth light emitter 5 respectively. The light focusing point of the first emitting lens 12 is at the position of the first light emitter 2; the light focusing point of the second emitting lens 13 is at the position of the second light emitter 3. The light focusing point of the third emitting lens 14 is at the position of the third light emitter 4. The light focusing point of the fourth emitting lens 15 is at the position of the fourth light emitter 5.

The first receiving lens 16, the second receiving lens 17, the third receiving lens 18 and the fourth receiving lens 19 are arranged in pairs, and each group corresponds to a receiver to receive light. The light focusing points of the first receiving lens 16 and the second receiving lens 17 are both at the location of the first light receiver 6, and the focal light is received by the first light receiver 6; the light focusing points of the third receiving lens 18 and the fourth receiving lens 19 are both at the location of the second light receiver 7, and the focal light is received by the second light receiver 7.

The first transmitting lens 12, the second transmitting lens 13, the third transmitting lens 14 and the fourth transmitting lens 15 are respectively conjugated with the second receiving lens 17, the fourth receiving lens 19, the first receiving lens 16 and the third receiving lens 18. The first transmitting lens 12 is conjugated with the second receiving lens 17; the second transmitting lens 13 is conjugated with the fourth receiving lens 19; the third transmitting lens 14 is conjugated with the first receiving lens 16; and the fourth transmitting lens 15 is conjugated with the third receiving lens 18.

The light isolation plate 22 is located between the front light lens 20 and the top light lens 21 to reduce light interference.

The locking buckle 23 includes a buckle 231 and a pressing column 232. The housing 9 includes a limiting column 91, a buckle column 92 and a buckle groove 93.

During installation, the buckle 231 corresponds to the buckle groove 93. After pressing hard, the buckle 231 hooks the buckle column 92, and the optical path component board 1 and the shell 9 are tightly connected together to form an inner cavity of the rainfall light sensor; the circuit board 8 is located in the cavity and is squeezed and fixed by the limiting column 91 and the clamping column 232.

Referring to FIG. 3, FIG. 6, FIG. 7 and FIG. 10, when light is emitted from a light-dense medium to a light-sparse medium, if the incident angle of the light is greater than the critical angle, total reflection will occur. In the present invention, the circuit board 8 controls the first light emitter 2, the second light emitter 3, the third light emitter 4, and the fourth light emitter 5 to emit infrared light, and the infrared light is respectively acted on by the first emission lens 12, the second emission lens 13, the third emission lens 14, and the fourth emission lens 15 to become parallel light and emit to the front windshield 24 of the car. The area where the parallel light is emitted on the front windshield 24 of the car is the rain-sensing area. When there is no rain, when the infrared light is emitted from the front windshield 24 of the car to the air, total reflection occurs because the designed incident angle of the light is greater than the critical angle. The total reflected light is respectively focused by the corresponding conjugate lens and focused on the first light receiver 6 or the second light receiver 7, and then converted into an electrical signal. When there are raindrops in the rain-sensing area, part of the light path changes, the amount of total reflected light received by the first light receiver 6 and the second light receiver 7 decreases, and the electrical signal weakens. According to the strength of the electrical signal, it is analyzed and processed to determine whether there is rain and the amount of rain, and output a control signal to control the wipers to automatically wipe the rain.

The design of the compensation lens 122, the left wing lens 123, and the right wing lens 124 of the present invention takes into account the emission angle and direction of the light source, collects the light that is not received by the main emission lens 121, and increases the light utilization rate by 1 times. The confocal design of the first receiving lens 16 and the second receiving lens 17 enables the first light receiver 6 to receive reflected light from two rain-sensing areas; the confocal design of the third receiving lens 18 and the fourth receiving lens 19 enables the second light receiver 7 to receive reflected light from two rain-sensing areas, thereby increasing the rain-sensing area of the present invention by 80%.

In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (5)

1. A vehicle-use rain and light sensor, characterized in that it comprises an optical path component board (1), a circuit board (8), a housing (9) and a silicone film (10); the circuit board (8) is placed in the housing (9); the optical path component board (1) and the housing (9) are fixedly connected; one side of the silicone film (10) is adhered to the outer side of the optical path component board (1), and the other side is adhered to the front windshield of the vehicle; A light transmitter component and a light receiver component are fixedly provided on the circuit board (8); the light transmitter component comprises a first light transmitter (2), a second light transmitter (3), a third light transmitter (4) and a fourth light transmitter (5); the light receiver component comprises a first light receiver (6) and a second light receiver (7); A transmitting lens assembly, a receiving lens assembly, a forward light lens (20) and a top light lens (21) are fixedly provided on the optical path assembly plate (1); the transmitting lens assembly comprises a first transmitting lens (12), a second transmitting lens (13), a third transmitting lens (14) and a fourth transmitting lens (15); the receiving lens assembly comprises a first receiving lens (16), a second receiving lens (17), a third receiving lens (18) and a fourth receiving lens (19); The first emitting lens (12), the second emitting lens (13), the third emitting lens (14) and the fourth emitting lens (15) are all emitting convex lenses with the same structure; the emitting convex lenses comprise an emitting main lens (121), a compensating lens (122), a left wing-shaped lens (123) and a right wing-shaped lens (124) with the same lens focusing point positions; the emitting main lens (121) and the compensating lens (122) are located opposite each other; the left wing-shaped lens (123) is located on the left side of the emitting main lens (121); and the right wing-shaped lens (124) is located on the right side of the emitting main lens (121); The transmitting main lens (121) has a convex lens surface (1211) for receiving light emitted by the light emitter component; The compensation lens (122) has two light guiding surfaces, namely a focusing surface (1221) and a reflecting surface (1222); The left wing lens (123) has two light guiding surfaces, namely a left wing focusing surface (1231) and a left wing reflecting surface (1232); The right wing-shaped lens (124) has two light guiding surfaces, namely a right wing focusing surface (1241) and a right wing reflecting surface (1242); The light focusing points of the transmitting lens assembly correspond one-to-one to the position of the light transmitting assembly; the light focusing points of the receiving lens assembly correspond to the position of the light receiving assembly, and the focused light of the two receiving lenses in the receiving lens assembly is received by a light receiver in the light receiving assembly; the transmitting lens assembly and the receiving lens assembly form a conjugate relationship respectively. 2. The vehicle rain and light sensor according to claim 1, characterized in that the incident angles of parallel light rays emitted from the emitting main lens (121), the compensating lens (122), the left wing lens (123), and the right wing lens (124) to the front windshield are the same. 3. The vehicle rain and light sensor according to claim 2, characterized in that: if the critical angle for total reflection of light in the absence of rain is θ ₁ and the critical angle for total reflection of light in the presence of rain is θ ₂ , then the incident angle θ of the parallel light emitted from the emitting lens assembly to the front windshield satisfies θ ₁ <θ<θ ₂ . 4. The vehicle-use rain and light sensor according to claim 3, characterized in that a light-isolating plate (22) is fixedly provided between the front light lens (20) and the top light lens (21). 5. The vehicle rain and light sensor according to claim 4, characterized in that: a locking buckle (23) is fixedly provided on the optical path component plate (1); the locking buckle (23) comprises a buckle (231) and a pressing column (232); and a buckle column (92) is fixedly provided on the housing (9) at a position corresponding to the buckle (231).