A transparent rain sensor

Abstract

The present invention discloses a transparent rain sensor, comprising a planar capacitor mounted on a car windshield and a sensor detection circuit connected to the planar capacitor, the planar capacitor is used as a sensitive element of the sensor, the two plates of the planar capacitor are placed on the same plane, the sensor detection circuit detects the capacitance change of the planar capacitor caused by the environmental influence, and generates a control signal for controlling the operation of the wiper device according to the detected capacitance change, characterized in that: the two plates of the planar capacitor are respectively a grid structure with a plurality of hollow parts, and the width of the reserved fine lines between the hollow parts is less than the width of the smallest object that the human eye can distinguish. The present invention sets the plate into a grid structure, and makes the fine line width less than the width of the smallest object that the human eye can distinguish, so that the plate forms a transparent structure, the plate area of ​​the transparent structure can be made larger, and the precision of the precise measurement is improved, the plate can be directly installed in the windshield or the interlayer of the windshield, the installation position can be set arbitrarily, will not affect the line of sight, and the installation is more flexible.

Description

Technical Field

[0001] The invention relates to a device for detecting environmental changes of a car windshield, in particular to a detection device for detecting changes in rainfall on a car windshield. Background Art

[0002] Since the beginning of the 21st century, automobile electronics and intelligence have become the direction and forefront of automobile industry technology development, and automobile safety and humanization have also become the focus of major automobile manufacturers. The automatic detection system is not only focused on the humanized care of the convenience of the driver, but more importantly, the automatic detection system is an important part of the active safety system of the car. On rainy days or in an environment with high relative humidity, the driver's vision is often affected by excessive rain on the surface of the car windshield.

[0003] For this purpose, the inventor applied for a Chinese invention patent with patent number CN200610083392.8, which was published on December 12, 2007. The invention discloses a planar capacitive sensor, including a planar capacitor installed on a car windshield and a sensor detection circuit connected to the planar capacitor. The planar capacitor serves as a sensitive element of the sensor, wherein the two electrodes of the planar capacitor are placed on the same plane. The sensor detection circuit detects the capacitance change of the planar capacitor caused by environmental influences, and generates a control signal for controlling the operation of the wiper device according to the detected capacitance change. The sensor detection circuit is also connected to a planar capacitor compensator for eliminating interference signals, whose two electrodes are placed on the same plane. The planar capacitor compensator only serves as a sensitive element for detecting interference signals. The sensor detection circuit detects the capacitance change of the planar capacitor compensator caused by the interference signal, and compensates the capacitance change of the planar capacitor caused by the environmental influence according to the detected capacitance change.

[0004] However, the installation space on the front windshield of the car is limited, and the planar capacitor cannot be made too large, nor can it be installed in a position that affects the line of sight, which limits the area and installation of the planar capacitor. In addition, the leads of the planar capacitor will also form a planar capacitor, and most of the leads are outside the working range of the wiper, so the leads will affect the detection accuracy of the sensor. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a transparent rainfall sensor which has a large area, is easy to install and has high detection accuracy.

[0006] A transparent rain sensor provided in accordance with the present invention comprises a planar capacitor mounted on a car windshield and a sensor detection circuit connected to the planar capacitor, wherein the planar capacitor serves as a sensitive element of the sensor, and the two electrodes of the planar capacitor are placed on the same plane. The sensor detection circuit detects the capacitance change of the planar capacitor caused by environmental influences, and generates a control signal for controlling the operation of the wiper device according to the detected capacitance change. The sensor is characterized in that the two electrodes of the planar capacitor are respectively a grid structure with a plurality of hollow portions, and the width of the retained fine lines between the hollow portions is smaller than the width of the smallest object that can be distinguished by the human eye.

[0007] A transparent rain sensor provided by the present invention also has the following additional technical features:

[0008] It further includes that the width of the thin line is less than or equal to 0.05mm, and the length and width of the hollow part are 1mm-2mm.

[0009] Further comprising, the area of ​​the plate is 1000-5000mm 2 .

[0010] It further includes that the electrode plate is connected to a lead wire, and the width of the lead wire is smaller than the width of the smallest object that can be distinguished by human eyes.

[0011] It further includes that the width of the lead is less than or equal to 0.05 mm, and the ratio of the spacing between adjacent lead wires to the width of the lead wire is 20-50.

[0012] Further comprising: the ratio of the area of ​​the lead to the area of ​​the electrode plate is 0.01-0.001.

[0013] It further includes that the electrode plate is attached to a substrate made of a transparent material.

[0014] It further includes that the electrode plate is made of a conductive material attached to the substrate through a nano-printing, printing or spraying process.

[0015] It further includes a planar capacitor compensator, wherein the two compensation plates of the planar capacitor compensator are placed on the same plane, and the compensation plate is located between the two plates of the planar capacitor, and the two compensation plates are respectively a grid structure with multiple hollow parts, and the width of the retained fine lines between the hollow parts of the compensation plates is smaller than the width of the smallest object that can be distinguished by the human eye.

[0016] It further includes that the width of the thin line is less than or equal to 0.05mm, and the length and width of the hollow part are 1mm-2mm.

[0017] A transparent rain sensor provided by the present invention has the following advantages compared with the prior art: First, the present invention sets the electrode plate into a grid structure, and makes the width of the fine line smaller than the width of the smallest object that can be distinguished by the human eye, so that the electrode plate forms a transparent structure, and the electrode plate area of ​​the transparent structure can be made larger, which improves the precision of the measurement, and the electrode plate can be directly installed in the windshield or the interlayer of the windshield. The installation position can be set arbitrarily, which will not affect the line of sight, and the installation is more flexible. Secondly, the lead wire in the present invention is set thinner, which not only does not affect the line of sight, but also because it is very thin, the plane capacitance formed is relatively weak, and the impact on the sensor is very low, which improves the detection accuracy of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view of the planar capacitor in the present invention;

[0019] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0020] Figure 3 It is a bottom view schematic diagram of the planar capacitor in the present invention. DETAILED DESCRIPTION

[0021] In order to clearly illustrate the scheme in the present invention, preferred embodiments are given below and described in detail with reference to the accompanying drawings. The following description is essentially only exemplary and is not intended to limit the application or use of the present disclosure. It should be understood that in all the drawings, corresponding reference numerals represent the same or corresponding parts and features.

[0022] like Figure 1 and Figure 2 As shown, a transparent rain sensor provided by the present invention includes a planar capacitor installed on a car windshield and a sensor detection circuit connected to the planar capacitor, the planar capacitor serves as a sensitive element of the sensor, the two plates of the planar capacitor are placed on the same plane, the sensor detection circuit detects the capacitance change of the planar capacitor caused by environmental influences, and generates a control signal for controlling the operation of the wiper device according to the detected capacitance change. This embodiment also includes a planar capacitor compensator for eliminating interference signals, the two compensation plates of the planar capacitor compensator are placed on the same plane, and the compensation plate is located between the two plates of the planar capacitor. The working principles of the planar capacitor, planar capacitor compensator and sensor detection circuit in this embodiment can all be found in the inventor's prior invention patent No. CN100571035C, and these structures and principles will not be repeated here.

[0023] The difference between the present invention and the prior patents is that the plate structure of the planar capacitor and the planar capacitor compensator has been improved, specifically: the two plates 10 and 20 of the planar capacitor are respectively a grid-like structure with multiple hollow parts 1, and the width of the retained fine lines 2 between the hollow parts 1 is less than the width of the smallest object that the human eye can distinguish. The two compensation plates are respectively a grid-like structure with multiple hollow parts, and the width of the retained fine lines between the hollow parts of the compensation plates is less than the width of the smallest object that the human eye can distinguish. In the above structure, the area of ​​the hollow part 1 is much larger than the area of ​​the fine line 2, and the width of the fine line 2 is less than the width of the smallest object that the human eye can distinguish, so that the final grid-like structure forms a transparent structure, and this transparent structure will not affect the line of sight. Therefore, the plate in the present invention can be installed at any position on the windshield, and can also be made into a larger area plate. The large-area positive plate can improve the detection accuracy.

[0024] See also Figure 1 and Figure 2 , further included in the above-mentioned embodiment given by the present invention, the width of the thin line 2 is less than or equal to 0.05mm, and the length and width of the hollow portion 1 are 1mm-2mm. The smallest object that the human eye can distinguish is generally around 0.1mm-0.2mm. In this embodiment, the width of the thin line 2 is set to 0.05mm. Of course, it can also be less than 0.05mm, such as 0.03mm, 0.01mm, but the thinnest needs to meet the conductivity requirements and strength requirements. Setting it to 0.05mm is enough to meet the needs of the transparent structure so that the thin line will not affect the line of sight. The hollow portion 1 in this embodiment is square, and the length and width are both 1mm. The area of ​​the hollow portion 1 is large enough relative to the thin line to meet the needs of the transparent structure, so that the entire plate becomes a transparent structure and will not affect the line of sight. The plate structure of the planar capacitor compensator in this embodiment is exactly the same as the plate structure of the planar capacitor.

[0025] See also Figure 1 and Figure 2 In the above embodiment of the present invention, the area of ​​the plates 10 and 20 is 1000-5000mm 2 In this embodiment, the 2 Therefore, the area of ​​the electrode plate in the present invention can be increased to become a large-area electrode plate.

[0026] See also Figure 1 and Figure 2In the above embodiment given by the present invention, the electrode plates 10 and 20 are further connected with a lead 3, and the width of the lead 3 is less than the width of the smallest object that can be distinguished by the human eye. If the width of the lead 3 is too large, a planar capacitor will also be formed. Since most of the structure of the lead is not within the working range of the wiper, the planar capacitor formed by the lead always has rainwater, which affects the detection accuracy of the sensor. The present invention also changes the lead 3 into a transparent thin wire structure, which not only does not affect the line of sight, but also the planar capacitor formed is very weak and does not affect the detection accuracy of the sensor.

[0027] See also Figure 1 and Figure 2 , further included in the above-mentioned embodiment given by the present invention, the width of the lead 3 is less than or equal to 0.05mm, and the ratio of the spacing between adjacent leads 3 to the width of the lead 3 is 20-50. The size of the lead 3 in the present invention is 0.05mm, and of course it can also be 0.03mm or 0.01mm. These sizes are smaller than the size of the smallest object that the human eye can distinguish, so that the lead will not affect the line of sight. In this embodiment, the ratio of the spacing between adjacent leads 3 to the width of the lead 3 is 20, and of course, it can also be set to 30 or 40. These ratio settings can basically eliminate the planar capacitance formed by the leads and improve the detection accuracy.

[0028] See also Figure 1 and Figure 2 In the above embodiment of the present invention, the ratio of the area of ​​the lead 3 to the area of ​​the plates 10 and 20 is 0.01-0.001. In this embodiment, the ratio is 0.02, 0.03 or 0.05, etc. The area of ​​the lead 3 is much smaller than the area of ​​the plates. Even if the lead forms a planar capacitor, the large difference between the two will not affect the planar capacitor formed by the plates.

[0029] See also Figure 1 , Figure 2 and Figure 3 In the above embodiment given by the present invention, the electrode plates 10 and 20 are further attached to a substrate 4 made of a transparent material. The electrode plates are made by attaching a conductive material to the substrate 4 through a nano-printing, printing or spraying process. The present invention manufactures the electrode plates on a transparent substrate, which is not only convenient for processing, but also conducive to later installation. Since the substrate is a transparent structure, it will not affect the line of sight.

[0030] In summary, the above contents are only embodiments of the present invention, which are only used to illustrate the principles of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A transparent rain sensor, comprising a planar capacitor mounted on a car windshield and a sensor detection circuit connected to the planar capacitor, wherein the planar capacitor is used as a sensitive element of the sensor, and two plates of the planar capacitor are placed on the same plane, and the sensor detection circuit detects the capacitance change of the planar capacitor caused by the environment, and generates a control signal for controlling the operation of a wiper device according to the detected capacitance change, characterized in that: The two plates of the planar capacitor are respectively a grid structure with multiple hollow parts, the width of the retained fine lines between the hollow parts is smaller than the width of the smallest object distinguishable by the human eye, the width of the retained fine lines between the hollow parts of the plates of the planar capacitor is less than or equal to 0.05mm, and the length and width of the hollow parts of the plates of the planar capacitor are 1mm-2mm.

2. A transparent rain sensor as claimed in claim 1, characterized in that: The area of ​​the plate is 1000-5000mm 2 .

3. A transparent rain sensor as claimed in claim 1, characterized in that: The electrode plate is connected with a lead wire, and the width of the lead wire is smaller than the width of the smallest object that can be distinguished by human eyes.

4. A transparent rain sensor as claimed in claim 3, characterized in that: The width of the lead is less than or equal to 0.05 mm, and the ratio of the spacing between adjacent lead wires to the width of the lead wire is 20-50.

5. A transparent rain sensor as claimed in claim 3, characterized in that: The ratio of the area of ​​the lead to the area of ​​the electrode plate is 0.01-0.

001.

6. A transparent rain sensor as claimed in claim 1, characterized in that: The plate is attached to a substrate made of a transparent material.

7. A transparent rain sensor as claimed in claim 6, characterized in that: The electrode plate is made by attaching a conductive material to the substrate through a nano-printing, printing or spraying process.

8. A transparent rain sensor as claimed in claim 1, characterized in that: It also includes a planar capacitor compensator, wherein the two compensation plates of the planar capacitor compensator are placed on the same plane, and the compensation plate is located between the two plates of the planar capacitor. The two compensation plates are respectively a grid structure with multiple hollow parts, and the width of the retained fine lines between the hollow parts of the compensation plates is smaller than the width of the smallest object that can be distinguished by the human eye.

9. A transparent rain sensor as claimed in claim 8, characterized in that: The width of the retained thin lines between the hollow parts of the compensation plate is less than or equal to 0.05 mm, and the length and width of the hollow parts of the compensation plate are 1 mm-2 mm.

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