Sunlight sensor using laser resistance trimming process

Abstract

A sunlight sensor using a laser resistance trimming process provided by the present invention comprises a light filter, an upper cover and a circuit board, the light filter and the upper cover define a cavity, the circuit board is electrically connected with a forward light circuit assembly and an upward light circuit assembly, the circuit board is located in the cavity, and the forward light circuit assembly is electrically connected with the upward light circuit assembly. The forward light circuit assembly comprises a first laser-cuttable resistor R3 with the resistance capable of being adjusted through laser, and the upward light circuit assembly comprises a second laser-cuttable resistor R9 with the resistance capable of being adjusted through laser. The invention provides a sunlight sensor product capable of improving the output precision through a laser resistance trimming process, and the sunlight sensor product is simple in structure, convenient to install and suitable for mass production.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a sunlight sensor using a laser resistance trimming process. Background Art

[0002] The car is in the following road conditions: When meeting other vehicles at night, if the other vehicle turns on the high beam while turning on the headlights, it will have a great impact on the driver's forward vision, and it is necessary to use lights in time to remind the oncoming vehicle to turn off the high beam. If the lights are not turned on in time due to poor product accuracy, an accident may occur; after the meeting, it is necessary to observe the surrounding objects at a distance for early judgment and reserve more operating space for the driver, so the high beam needs to be turned on. If the driver manually adjusts the low beam to the high beam, the time difference in the middle may also cause an accident; and the sunlight sensors pasted on the windshield on the market are currently the most criticized issues in China because the key component chips are all manufactured abroad, and their low accuracy, long delivery time, and high price have become the most criticized issues in China. The accuracy of sunlight sensors has been slow to be improved, and parts manufacturers often use manual turning on of high and low beams, which increases the probability of accidents.

[0003] Therefore, it is necessary to design a high-precision sunlight sensor product that can accurately detect the light above and forward of the vehicle before and after meeting other vehicles at night and automatically control the switching of high and low beam headlights to achieve the purpose of safe and intelligent driving. At the same time, it can be mass-produced with low production cost and good consistency. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a sunlight sensor using a laser resistance trimming process. The present invention at least solves some of the problems in the prior art.

[0005] The present invention is achieved in that:

[0006] The present invention provides a sunlight sensor using a laser resistance trimming process, comprising an optical filter, an upper cover and a circuit board, wherein the optical filter and the upper cover enclose a chamber, a forward optical circuit component and an upper optical circuit component are electrically connected to the circuit board, the circuit board is located in the chamber, the forward optical circuit component comprises a first laser-cuttable resistor R3 that can be laser-trimmed, and the upper optical circuit component comprises a second laser-cuttable resistor R9 that can be laser-trimmed.

[0007] Furthermore, a pin socket is provided in the optical filter, and the pin socket is welded to the circuit board.

[0008] Furthermore, a power protection circuit component, a voltage stabilizing circuit component, and a voltage divider circuit component are electrically connected to the circuit board. The power protection circuit component, the voltage stabilizing circuit component, and the voltage divider circuit component are electrically connected in sequence. The input end of the power protection circuit component is electrically connected to an external power supply, and the input end of the forward optical circuit component and the input end of the upper optical circuit component are both electrically connected to the output end of the voltage divider circuit component.

[0009] Furthermore, the power protection circuit component includes a first filter capacitor C1 and a first voltage transient suppression tube D2, the voltage stabilizing circuit component includes a rectifier diode D1, a voltage stabilizing transistor U1, a second filter capacitor C2, and a third filter capacitor C3, the voltage divider circuit component includes a first voltage divider resistor R1 and a second voltage divider resistor R2, the input end of the first filter capacitor C1, the input end of the first voltage transient suppression tube D2, and the input end of the rectifier diode D1 are all electrically connected to the power pin PIN8 of the pin socket, and the input end of the voltage stabilizing transistor U1 and the input end of the second filter capacitor C2 are all electrically connected to the output end of the rectifier diode D1. The input end of the third filter capacitor C3 and the input end of the first voltage-dividing resistor R1 are electrically connected to the output end of the voltage-regulating transistor U1, the output end of the first filter capacitor C1, the output end of the first voltage transient suppression tube D2, the output end of the second filter capacitor C2, the ground end of the voltage-regulating transistor U1, and the output end of the third filter capacitor C3 are electrically connected to the ground pin PIN2 of the pin socket, the output end of the first voltage-dividing resistor R1 is grounded through the second voltage-dividing resistor R2, and the input end of the forward optical circuit assembly and the input end of the upper optical circuit assembly are electrically connected to the output end of the first voltage-dividing resistor R1.

[0010] Furthermore, the forward optical circuit assembly also includes a first photosensitive component PD1, a first operational amplifier U3, a first fixed resistor R8, a first anti-interference capacitor C4, a first current limiting resistor R4, a fourth filter capacitor C5, and a second voltage transient suppression tube D3. The positive electrode of the first photosensitive component PD1 and the positive input terminal of the first operational amplifier U3 are electrically connected to the output terminal of the first voltage-dividing resistor R1, the power pin of the first operational amplifier U3 is electrically connected to the output terminal of the voltage-stabilizing transistor U1, and the negative electrode of the first photosensitive component PD1, one end of the first switchable resistor R3, and one end of the first anti-interference capacitor C4 are electrically connected to the negative input terminal of the first operational amplifier U3. The other end of the first switchable resistor R3 is connected in series with the first fixed resistor R8 and then electrically connected to the output end of the first operational amplifier U3. The other end of the first anti-interference capacitor C4 is electrically connected to the output end of the first operational amplifier U3. The output end of the first operational amplifier U3 is electrically connected to the forward optical circuit output pin PIN5 of the pin socket through the first current limiting resistor R4. The input end of the fourth filter capacitor C5 and the negative electrode of the second voltage transient suppression tube D3 are electrically connected to the forward optical circuit output pin PIN5 of the pin socket. The ground end of the first operational amplifier U3, the output end of the fourth filter capacitor C5 and the positive electrode of the second voltage transient suppression tube D3 are electrically connected to the ground pin PIN2 of the pin socket.

[0011] Furthermore, the upper optical circuit assembly also includes a second photosensitive component PD4, a second operational amplifier U2, a second fixed resistor R5, a second anti-interference capacitor C6, a second current limiting resistor R10, a fifth filter capacitor C8 and a third voltage transient suppression tube D4, the positive electrode of the second photosensitive component PD4 and the positive input terminal of the second operational amplifier U2 are electrically connected to the output terminal of the first voltage-dividing resistor R1, the power pin of the second operational amplifier U2 is electrically connected to the output terminal of the voltage-stabilizing transistor U1, the negative electrode of the second photosensitive component PD4, one end of the second switchable resistor R9, and one end of the second anti-interference capacitor C6 are electrically connected to the negative input terminal of the second operational amplifier U2 The other end of the second switchable resistor R9 is connected in series with the second fixed resistor R5 and then electrically connected to the output end of the second operational amplifier U2. The other end of the second anti-interference capacitor C6 is electrically connected to the output end of the second operational amplifier U2. The output end of the second operational amplifier U2 is electrically connected to the upper optical circuit output pin PIN7 of the pin socket through the second current limiting resistor R10. The input end of the fifth filter capacitor C8 and the negative electrode of the third voltage transient suppression tube D4 are electrically connected to the upper optical circuit output pin PIN7 of the pin socket. The ground end of the second operational amplifier U2, the output end of the fifth filter capacitor C8 and the positive electrode of the third voltage transient suppression tube D4 are electrically connected to the ground pin PIN2 of the pin socket.

[0012] Furthermore, the first photosensitive component PD1 and the second photosensitive component PD4 are both photodiodes.

[0013] Furthermore, a positioning post is provided in the filter, and a positioning groove which is engaged with the positioning post is provided on the circuit board.

[0014] Furthermore, a coupling adhesive for bonding with a windshield of a car is provided on a side of the filter facing away from the upper cover.

[0015] Furthermore, the sunlight sensor using the laser resistance trimming process also includes a mounting card for mounting the sunlight sensor on the interior rearview mirror, and the mounting card is fixedly connected to the upper cover.

[0016] The present invention has the following beneficial effects:

[0017] 1. The present invention provides a sunlight sensor product that can improve output accuracy through laser resistance trimming technology. It has a simple structure, is easy to install, and is suitable for mass production.

[0018] 2. The present invention provides a sunlight sensor circuit that meets the requirements of electromagnetic compatibility (EMC), can detect forward light and upward light at the same time, and the two signals are output separately without interfering with each other.

[0019] 3. In the present invention, the input ends of the forward optical circuit and the upper optical circuit share a 12V voltage signal, and the amplification factors of the two circuits can be achieved by laser resistance adjustment to achieve the output voltage reaching the target parameters, which provides a guarantee for the high performance of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 An exploded diagram of a sunlight sensor using a laser resistance trimming process provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of an optical filter provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of a sunlight sensor circuit using a laser resistance trimming process provided by an embodiment of the present invention;

[0024] Figure 4 The embodiment of the present invention provides Figure 3 Enlarged image on the left;

[0025] Figure 5 The embodiment of the present invention provides Figure 3 Enlarged image on the right.

[0026] In the figure: coupling glue 1, filter 2, positioning column 201, circuit board 3, positioning groove 301, upper cover 4, mounting card 5, pin holder 6, pin 601 on the pin holder. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1-Figure 5 The embodiment of the present invention provides a sunlight sensor using a laser resistance trimming process, including a filter 2, an upper cover 4 and a circuit board 3. The upper cover 4 covers the filter 2. The filter 2 and the upper cover 4 enclose a chamber. The circuit board 3 is electrically connected to a forward optical circuit component and an upper optical circuit component. The circuit board 3 is located in the chamber. The forward optical circuit component includes a first laser-cut resistor R3 that can be laser-trimmed, and the upper optical circuit component includes a second laser-cut resistor R9 that can be laser-trimmed. In this embodiment, the filter 2 is snap-connected to the upper cover 4.

[0029] In the present invention, the forward optical circuit assembly and the upper optical circuit assembly can adapt to filters with different transmittance values, and there is no special requirement for the transmittance of the lens in the filter. The first laser-cut resistor R3 and the second laser-cut resistor R9 can change the resistance value through the laser resistance adjustment process to adapt to the transmittance values ​​of different filters, so that the output voltage of the forward optical circuit and the upper optical circuit meets the requirements. The first laser-cut resistor R3 and the second laser-cut resistor R9 improve the accuracy of the sunlight sensor, are easy to process and reduce the production cost, and meet the user's demand for high-precision sunlight sensor products. The sunlight sensor can accurately detect the upper light and forward light of the vehicle before and after meeting the vehicle at night, and automatically control the switching of the high and low beam lights, achieving the purpose of safe and intelligent driving. The present invention uses laser resistance adjustment to change the resistance value of the first laser-cut resistor R3 and the second laser-cut resistor R9, and there is no risk of cold welding and leaking welding caused by manual welding and replacement of resistors.

[0030] In this embodiment, a pin holder 6 is provided in the optical filter 2, and the pin holder 6 is welded to the circuit board 3. The pins 601 on the pin holder are welded to the circuit board 3, and can play the function of fixing the circuit board 3. In this embodiment, the pin holder 6 is injection molded into the optical filter 2.

[0031] In this embodiment, the circuit board 3 is also electrically connected to a power protection circuit component, a voltage stabilizing circuit component, and a voltage divider circuit component. The power protection circuit component, the voltage stabilizing circuit component, and the voltage divider circuit component are electrically connected in sequence. The input end of the power protection circuit component is electrically connected to an external power supply, and the input end of the forward optical circuit component and the input end of the upper optical circuit component are both electrically connected to the output end of the voltage divider circuit component. In this embodiment, the forward optical circuit input end and the upper optical circuit input end share a 12V power supply voltage.

[0032] In this embodiment, the power protection circuit component includes a first filter capacitor C1 and a first voltage transient suppression tube D2, the voltage stabilizing circuit component includes a rectifier diode D1, a voltage stabilizing transistor U1, a second filter capacitor C2, and a third filter capacitor C3, the voltage divider circuit component includes a first voltage divider resistor R1 and a second voltage divider resistor R2, the input end of the first filter capacitor C1, the input end of the first voltage transient suppression tube D2, and the input end of the rectifier diode D1 are all electrically connected to the power pin PIN8 of the pin socket 6, the input end of the voltage stabilizing transistor U1 and the input end of the second filter capacitor C2 are all connected to the output end of the rectifier diode D1 The input end of the third filter capacitor C3 and the input end of the first voltage-dividing resistor R1 are electrically connected to the output end of the voltage-regulating transistor U1, the output end of the first filter capacitor C1, the output end of the first voltage transient suppression tube D2, the output end of the second filter capacitor C2, the ground end of the voltage-regulating transistor U1, and the output end of the third filter capacitor C3 are electrically connected to the ground pin PIN2 of the pin socket 6, the output end of the first voltage-dividing resistor R1 is grounded through the second voltage-dividing resistor R2, and the input end of the forward optical circuit assembly and the input end of the upper optical circuit assembly are electrically connected to the output end of the first voltage-dividing resistor R1.

[0033] In this embodiment, the forward optical circuit assembly also includes a first photosensitive component PD1, a first operational amplifier U3, a first fixed resistor R8, a first anti-interference capacitor C4, a first current limiting resistor R4, a fourth filter capacitor C5 and a second voltage transient suppression tube D3. The positive electrode of the first photosensitive component PD1 and the positive input terminal of the first operational amplifier U3 are electrically connected to the output terminal of the first voltage-dividing resistor R1, the power pin of the first operational amplifier U3 is electrically connected to the output terminal of the voltage-stabilizing transistor U1, and the negative electrode of the first photosensitive component PD1, one end of the first switchable resistor R3, and one end of the first anti-interference capacitor C4 are electrically connected to the negative input terminal of the first operational amplifier U3. The other end of the first switchable resistor R3 is connected in series with the first fixed resistor R8 and then electrically connected to the output end of the first operational amplifier U3. The other end of the first anti-interference capacitor C4 is electrically connected to the output end of the first operational amplifier U3. The output end of the first operational amplifier U3 is electrically connected to the forward optical circuit output pin PIN5 of the pin socket 6 through the first current limiting resistor R4. The input end of the fourth filter capacitor C5 and the negative electrode of the second voltage transient suppression tube D3 are electrically connected to the forward optical circuit output pin PIN5 of the pin socket 6. The ground end of the first operational amplifier U3, the output end of the fourth filter capacitor C5 and the positive electrode of the second voltage transient suppression tube D3 are electrically connected to the ground pin PIN2 of the pin socket 6.

[0034] In this embodiment, the upper optical circuit assembly also includes a second photosensitive component PD4, a second operational amplifier U2, a second fixed resistor R5, a second anti-interference capacitor C6, a second current limiting resistor R10, a fifth filter capacitor C8 and a third voltage transient suppression tube D4, the positive electrode of the second photosensitive component PD4 and the positive input end of the second operational amplifier U2 are electrically connected to the output end of the first voltage-dividing resistor R1, the power pin of the second operational amplifier U2 is electrically connected to the output end of the voltage-stabilizing transistor U1, the negative electrode of the second photosensitive component PD4, one end of the second switchable resistor R9, and one end of the second anti-interference capacitor C6 are electrically connected to the negative input end of the second operational amplifier U2 , the other end of the second switchable resistor R9 is connected in series with the second fixed resistor R5 and then electrically connected to the output end of the second operational amplifier U2, the other end of the second anti-interference capacitor C6 is electrically connected to the output end of the second operational amplifier U2, the output end of the second operational amplifier U2 is electrically connected to the upper optical circuit output pin PIN7 of the pin socket 6 through the second current limiting resistor R10, the input end of the fifth filter capacitor C8 and the negative electrode of the third voltage transient suppression tube D4 are electrically connected to the upper optical circuit output pin PIN7 of the pin socket 6, the ground end of the second operational amplifier U2, the output end of the fifth filter capacitor C8 and the positive electrode of the third voltage transient suppression tube D4 are electrically connected to the ground pin PIN2 of the pin socket 6. The power pin PIN8 of the pin socket 6, the ground pin PIN2 of the pin socket 6, the forward optical circuit output pin PIN5 of the pin socket 6, and the upper optical circuit output pin PIN7 of the pin socket 6 are four different pins on the pin socket 6.

[0035] In this embodiment, both the first photosensitive component PD1 and the second photosensitive component PD4 are photodiodes.

[0036] In this embodiment, a positioning post 201 is provided in the filter 2, and a positioning groove 301 is provided on the circuit board 3 to engage with the positioning post 201. The positioning post 201 has an anti-mistake installation function, which facilitates accurate positioning and installation of the circuit board 3.

[0037] In this embodiment, a coupling adhesive 1 for bonding with a car windshield is provided on the side of the optical filter 2 facing away from the upper cover 4. In this embodiment, the coupling adhesive 1 is fixed on the optical filter housing 2 by a two-component dispensing process.

[0038] In this embodiment, the sunlight sensor using the laser resistance trimming process further includes a mounting card 5 for mounting the sunlight sensor on the interior rearview mirror, and the mounting card 5 is fixedly engaged with the upper cover 4 .

[0039] In the present invention, ESD electrostatic protection elements (a first voltage transient suppression tube D2, a second voltage transient suppression tube D3 and a third voltage transient suppression tube D4) are connected in parallel at both the voltage input and output ends to prevent damage to components in the circuit caused by self-oscillation and abnormal surges. The present invention provides a circuit that can meet the requirements of electromagnetic compatibility (EMC).

[0040] The laser resistance trimming method of the present invention is applied to the above-mentioned sunlight sensor using the laser resistance trimming process: after setting the resistance trimming target parameters in the software interface of the laser resistance trimming equipment, a laser beam with appropriate power density is focused on the first laser-cuttable resistor R3 and the second laser-cuttable resistor R9. The laser-cuttable resistor material is vaporized instantly due to the high temperature. As the laser beam etches and the laser-cuttable resistor is cut, the conductive cross-sectional area of ​​the resistor body decreases and the resistance value increases. The resistance trimming is stopped immediately after the output voltage of the forward optical circuit and the upper optical circuit reaches the resistance trimming target value. The product after resistance trimming has good consistency and high precision.

[0041] like Figure 3-Figure 5 The embodiment of the present invention provides a sunlight sensor circuit using a laser resistance trimming process, which is specifically implemented as follows:

[0042] The power protection circuit includes a first voltage transient suppression tube D2 and a first filter capacitor C1. The maximum voltage that the first voltage transient suppression tube D2 can withstand is 24V. When transients caused by electrostatic discharge ESD or lightning occur, the first voltage transient suppression tube D2 will be directly broken down, thereby protecting other components in the subsequent circuit.

[0043] The voltage stabilizing circuit includes a rectifier diode D1, a voltage stabilizing transistor U1, a second filter capacitor C2 and a third filter capacitor C3. The 12V power supply is connected to the rectifier diode D1 through the power pin PIN8 of the pin socket 6 to convert the AC power into DC power, and then the voltage is clamped at 5V through the voltage stabilizing transistor U1.

[0044] The voltage-dividing circuit includes a first voltage-dividing resistor R1 and a second voltage-dividing resistor R2. The output end of the voltage-regulating transistor U1 is connected to the input end of the first voltage-dividing resistor R1. Meanwhile, the first voltage-dividing resistor R1 is connected in series with the second voltage-dividing resistor R2. The output end of the second voltage-dividing resistor R2 is electrically connected to the ground pin PIN2 of the pin socket 6. The positive input end of the first operational amplifier U3 is connected to the input end of the second voltage-dividing resistor R2, thereby ensuring that the voltage reference value of the positive input end of the first operational amplifier U3 remains unchanged.

[0045] Forward light circuit: the positive electrode of the first photosensitive component PD1 is connected to the positive input terminal of the first operational amplifier U3, the negative electrode of the first photosensitive component PD1 is simultaneously connected to the negative input terminal of the first operational amplifier U3 and one end of the first switchable resistor R3, the first switchable resistor R3 is connected in series with the first fixed resistor R8, and the other end of the first fixed resistor R8 is connected to the output terminal of the first operational amplifier U3; the output terminal of the first operational amplifier U3 is connected to the first current limiting resistor R4, the fourth filter capacitor C5 and the second voltage transient suppression tube D3; after the circuit is connected to a 12V voltage, under certain lighting conditions, the voltage of the final output forward light reaches the target parameter value of the resistance adjustment through etching by the laser beam, without requiring the transmittance of the lens in the filter, and there is no risk of cold soldering and leaking soldering caused by manual soldering to replace the resistor; the first current limiting resistor R4 is electrically connected to the forward light circuit output pin PIN5 of the pin socket 6 to prevent the output current from being too large; the second voltage transient suppression tube D3 prevents the abnormally large voltage and large current in the surrounding area from damaging the components in the subsequent circuit.

[0046] Under no-light conditions, the first operational amplifier U3 acts as a voltage follower, and the voltage at the output end is close to the reference voltage at the input end; when the light intensity gradually increases, a reverse current will be generated at both ends of the first photosensitive component PD1, causing the voltage across the first switchable resistor R3 and the first fixed resistor R8 to gradually increase, and the output voltage of the first operational amplifier U3 will also increase accordingly, thus forming a positive feedback circuit.

[0047] Upper optical circuit: the positive electrode of the second photosensitive component PD4 is connected to the positive input terminal of the second operational amplifier U2, the negative electrode of the second photosensitive component PD4 is simultaneously connected to the negative input terminal of the second operational amplifier U2 and one end of the second switchable resistor R9, the second switchable resistor R9 is connected in series with the second fixed resistor R5, and the other end of the second fixed resistor R5 is connected to the output terminal of the second operational amplifier U2; the output terminal of the second operational amplifier U2 is connected to the second current limiting resistor R10, the fifth filter capacitor C8 and the third voltage transient suppression tube D4; after the circuit is connected to a 12V voltage, under certain lighting conditions, the voltage of the final output forward light reaches the target parameter value of the resistance adjustment through etching by the laser beam, without requiring the light transmittance of the lens in the filter, and there is no risk of cold soldering and leaking soldering caused by manual soldering to replace the resistor; the second current limiting resistor R10 is electrically connected to the upper optical circuit output pin PIN7 of the pin socket 6 to prevent the output current from being too large; the third voltage transient suppression tube D4 prevents abnormally large voltages and large currents in the surrounding area from damaging components in subsequent circuits.

[0048] Under no-light conditions, the second operational amplifier U2 acts as a voltage follower, and the voltage at the output end is close to the reference voltage at the input end; when the light intensity gradually increases, a reverse current will be generated at both ends of the second photosensitive component PD4, causing the voltage across the second switchable resistor R9 and the second fixed resistor R5 to gradually increase, and the output voltage of the second operational amplifier U2 will also increase accordingly, thus forming a positive feedback circuit.

[0049] The sunlight sensor provided by the present invention has a simple structure and is easy to install. It has been supplied in batches to SAIC Roewe IP42, AP31 and other platform models.

[0050] The first laser-cuttable resistor R3 and the second laser-cuttable resistor R9 achieve consistency in the output voltage of the product test through a laser resistance trimming process under specific lighting conditions.

[0051] In the positive feedback amplifier circuit, the switchable resistor and the fixed resistor are connected in series to form an amplification factor. By adjusting the resistance of the switchable resistor, the output voltage same as the target parameter is achieved after circuit amplification, ultimately improving the first-time qualified rate of finished products, reducing rework costs, and shortening the production cycle.

[0052] In the present invention, the forward optical circuit and the upper optical circuit input terminals share a 12V power supply voltage, but the signal processing circuits are independent devices, the first switchable resistor R3 and the second switchable resistor R9 are resistors in independent circuits, are not affected by the resistance adjustment target parameters, and do not interfere with each other. At the same time, functional pins are saved, space is reserved for other functional designs, the number of components used is reduced, and costs are saved.

[0053] In this embodiment, the installation card 5 is tightly matched with the assembly position in the upper cover 4 through two limit blocks; the installation card 5 is assembled with the bracket structure in the rearview mirror of the customer's vehicle.

[0054] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sunlight sensor using a laser resistance trimming process, characterized in that: It includes an optical filter, an upper cover and a circuit board. The optical filter and the upper cover enclose a chamber. The circuit board is electrically connected to a forward optical circuit component and an upper optical circuit component. The circuit board is located in the chamber. The forward optical circuit component includes a first laser-cuttable resistor R3 that can be laser-adjusted, and the upper optical circuit component includes a second laser-cuttable resistor R9 that can be laser-adjusted.

2. The sunlight sensor using laser resistance trimming process as claimed in claim 1, characterized in that: A pin socket is arranged in the optical filter, and the pin socket is welded to the circuit board.

3. The sunlight sensor using laser resistance trimming process as claimed in claim 2, characterized in that: The circuit board is also electrically connected to a power protection circuit component, a voltage stabilizing circuit component, and a voltage divider circuit component. The power protection circuit component, the voltage stabilizing circuit component, and the voltage divider circuit component are electrically connected in sequence. The input end of the power protection circuit component is electrically connected to an external power supply, and the input end of the forward optical circuit component and the input end of the upper optical circuit component are both electrically connected to the output end of the voltage divider circuit component.

4. The sunlight sensor using laser resistance trimming process as claimed in claim 3, characterized in that: The power protection circuit assembly includes a first filter capacitor C1 and a first voltage transient suppression tube D2, the voltage stabilizing circuit assembly includes a rectifier diode D1, a voltage stabilizing transistor U1, a second filter capacitor C2, and a third filter capacitor C3, the voltage divider circuit assembly includes a first voltage divider resistor R1 and a second voltage divider resistor R2, the input end of the first filter capacitor C1, the input end of the first voltage transient suppression tube D2, and the input end of the rectifier diode D1 are all electrically connected to the power pin PIN8 of the pin socket, the input end of the voltage stabilizing transistor U1 and the input end of the second filter capacitor C2 are all electrically connected to the output end of the rectifier diode D1, The input end of the third filter capacitor C3 and the input end of the first voltage-dividing resistor R1 are electrically connected to the output end of the voltage-regulating transistor U1, the output end of the first filter capacitor C1, the output end of the first voltage transient suppression tube D2, the output end of the second filter capacitor C2, the ground end of the voltage-regulating transistor U1, and the output end of the third filter capacitor C3 are electrically connected to the ground pin PIN2 of the pin socket, the output end of the first voltage-dividing resistor R1 is grounded through the second voltage-dividing resistor R2, and the input end of the forward optical circuit assembly and the input end of the upper optical circuit assembly are electrically connected to the output end of the first voltage-dividing resistor R1.

5. The sunlight sensor using laser resistance trimming process as claimed in claim 4, characterized in that: The forward optical circuit assembly also includes a first photosensitive component PD1, a first operational amplifier U3, a first fixed resistor R8, a first anti-interference capacitor C4, a first current limiting resistor R4, a fourth filter capacitor C5 and a second voltage transient suppression tube D3. The positive electrode of the first photosensitive component PD1 and the positive input terminal of the first operational amplifier U3 are electrically connected to the output terminal of the first voltage-dividing resistor R1, the power pin of the first operational amplifier U3 is electrically connected to the output terminal of the voltage-stabilizing transistor U1, the negative electrode of the first photosensitive component PD1, one end of the first switchable resistor R3, and one end of the first anti-interference capacitor C4 are electrically connected to the negative input terminal of the first operational amplifier U3, and the The other end of the first switchable resistor R3 is connected in series with the first fixed resistor R8 and then electrically connected to the output end of the first operational amplifier U3. The other end of the first anti-interference capacitor C4 is electrically connected to the output end of the first operational amplifier U3. The output end of the first operational amplifier U3 is electrically connected to the forward optical circuit output pin PIN5 of the pin socket through the first current limiting resistor R4. The input end of the fourth filter capacitor C5 and the negative electrode of the second voltage transient suppression tube D3 are electrically connected to the forward optical circuit output pin PIN5 of the pin socket. The ground end of the first operational amplifier U3, the output end of the fourth filter capacitor C5 and the positive electrode of the second voltage transient suppression tube D3 are electrically connected to the ground pin PIN2 of the pin socket.

6. The sunlight sensor using laser resistance trimming process as claimed in claim 5, characterized in that: The upper optical circuit assembly also includes a second photosensitive component PD4, a second operational amplifier U2, a second fixed resistor R5, a second anti-interference capacitor C6, a second current limiting resistor R10, a fifth filter capacitor C8 and a third voltage transient suppression tube D4. The positive electrode of the second photosensitive component PD4 and the positive input terminal of the second operational amplifier U2 are electrically connected to the output terminal of the first voltage-dividing resistor R1, the power pin of the second operational amplifier U2 is electrically connected to the output terminal of the voltage-stabilizing transistor U1, the negative electrode of the second photosensitive component PD4, one end of the second switchable resistor R9, and one end of the second anti-interference capacitor C6 are electrically connected to the negative input terminal of the second operational amplifier U2. The other end of the second switchable resistor R9 is connected in series with the second fixed resistor R5 and then electrically connected to the output end of the second operational amplifier U2. The other end of the second anti-interference capacitor C6 is electrically connected to the output end of the second operational amplifier U2. The output end of the second operational amplifier U2 is electrically connected to the upper optical circuit output pin PIN7 of the pin socket through the second current limiting resistor R10. The input end of the fifth filter capacitor C8 and the negative electrode of the third voltage transient suppression tube D4 are electrically connected to the upper optical circuit output pin PIN7 of the pin socket. The ground end of the second operational amplifier U2, the output end of the fifth filter capacitor C8 and the positive electrode of the third voltage transient suppression tube D4 are electrically connected to the ground pin PIN2 of the pin socket.

7. The sunlight sensor using laser resistance trimming process as claimed in claim 6, characterized in that: The first photosensitive component PD1 and the second photosensitive component PD4 are both photodiodes.

8. The sunlight sensor using laser resistance trimming process as claimed in claim 1, characterized in that: A positioning post is arranged in the filter, and a positioning groove which is engaged with the positioning post is arranged on the circuit board.

9. The sunlight sensor using laser resistance trimming process as claimed in claim 1, characterized in that: A coupling adhesive for bonding with a windshield of an automobile is arranged on a side of the filter away from the upper cover.

10. The sunlight sensor using laser resistance trimming process as claimed in claim 1, characterized in that: It also includes an installation card for installing the sunlight sensor on the interior rearview mirror of the vehicle, and the installation card is fixedly connected with the upper cover.

Images