31results about How to "Good temperature characteristics" patented technology

The invention relates to the technical field of surfactants for oil field oil extraction, in particular to a surfactant for oil field oil extraction and a preparation method thereof.The surfactant is prepared from, by weight, 15-20 parts of polymer surfactants, 8-12 parts of enhancing auxiliaries, 6-8 parts of temperature-sensitive microspheres and 80-90 parts of water, the problems that an existing surfactant for oil extraction in an oil field is insufficient in activity and poor in effect are solved by compounding a high-molecular surfactant, a reinforcing auxiliary agent containing a hyperbranched structure and temperature-sensitive microspheres loaded with microorganisms, and meanwhile, the surfactant has a certain temperature-sensitive characteristic and can play a role in the deep position of an oil layer to form a plugging and flooding composite effect; therefore, the crude oil recovery rate of surfactant flooding can be well improved.

The invention belongs to the technical field of electronic reconnaissance, and discloses an ultra-wideband radio frequency receiving front-end SIP module system based on HTCC, which comprises a three-dimensional package for signal transmission, and the three-dimensional package comprises a BGA layer, a package internal signal transmission layer, a top microstrip wiring and a device placement layer; the miniaturization advantage is obvious: the packaging substrate is formed by sintering aluminum oxide ceramic at high temperature, and the packaging substrate has 12 layers and is small in size. And the system integration degree is high: a single SIP module can be integrated with radio frequency front-end systems such as an amplitude limiter, a radio frequency switch, a filter, a low noise amplifier, a digital control attenuator and the like, so that related function indexes are realized. According to the radio frequency transmission line and power supply structure design, the structure comprises a radio frequency signal transmission line and a power supply distribution line. Wherein the routing of the radio frequency layer adopts a quasi-coaxial-strip line-quasi-coaxial structure, and good signal transmission can be realized in a frequency band of 2-10GHz.

The invention relates to the technical field of ceramic materials, in particular to a high-temperature impedance X7R dielectric ceramic material and a preparation method and application thereof.The high-temperature impedance X7R dielectric ceramic material is prepared from main powder, a doping agent, a dispersing agent and a binding agent, the main powder is prepared from BaTiO3 and Na0. 5Bi0. 5TiO3 according to the molar ratio of 9: 1 through ball milling and presintering, the presintering temperature ranges from 1200 DEG C to 1400 DEG C, and the presintering time ranges from 2 h to 4 h; the doping agent is obtained by pre-sintering Nb2O5, transition metal oxide MeO and MgCO3, the pre-sintering temperature is 650 to 750 DEG C, and the pre-sintering time is 1 to 2 hours; the main powder is 100 parts by mole, the Nb2O5 is 0.1 to 1.0 part by mole, the MgCO3 is 0.1 to 1.0 part by mole, and the transition metal oxide MeO is 0.1 to 3.0 parts by mole. The temperature characteristic of the dielectric ceramic is improved, and the temperature stability of the dielectric ceramic meets the X7R dielectric material standard formulated by the American Electronic Industry Association.

The invention relates to a cantilever beam type capacitance MEMS acceleration sensor. The cantilever beam type capacitance MEMS acceleration sensor comprises an upper wafer layer, a middle wafer layer and a lower wafer layer which are arranged in sequence, the middle wafer layer is used for forming a movable mass block, a fixed electrode and an anchor point; the number of the anchor point is one, the anchor point is located at the first end of the movable mass block, and the anchor point is connected with the first end of the movable mass block through an elastic beam; a differential capacitor group is formed between the movable mass block and the fixed electrode along one or more directions, so that the acceleration in one or more directions can be measured; the upper wafer layer and the lower wafer layer are respectively connected with the middle wafer layer from two sides, and the fixed electrode and the anchor point are connected with the upper wafer layer and / or the lower wafer layer. According to the invention, the requirement of multi-axis detection is met, and the area utilization rate and the working reliability of the movable mass block are improved at the same time.

The invention relates to the technical field of ceramic capacitors, in particular to an X6S characteristic high-capacity multilayer chip ceramic capacitor and a preparation method thereof, the capacitor is formed by overlapping a dielectric ceramic layer and an inner electrode, and two ends of the capacitor are provided with outer electrodes which are connected with the inner electrode. The dielectric ceramic layer is formed by the dielectric ceramic material. According to the preparation method, barium titanate particles with specific average particle size, a doping agent with specific composition and specific preparation conditions are utilized to prepare the multilayer chip ceramic capacitor. Compared with the prior art, the dielectric material and the corresponding capacitor have both X6S characteristic temperature stability and high capacity, and still have high IR characteristic and low dielectric loss factor (tan delta) even in a high-temperature environment.

The invention discloses a preparation method of an aluminum electrolytic capacitor, and relates to the technical field of capacitors. The method at least comprises the following steps: winding an anode foil, double-layer electrolytic paper and a cathode foil into a core package; carrying out impregnation treatment on the core package; and drying the impregnated core package and putting the core package into a shell to form the aluminum electrolytic capacitor. Wherein the double-layer electrolytic paper comprises a microporous layer and a base material layer, the microporous layer is arranged close to the anode foil, conductive graphite is adsorbed on the microporous layer, the raw material of the microporous layer is bamboo pulp fiber, and the raw material of the base material layer is bamboo pulp fiber and wood pulp fiber. The electrolytic paper of the aluminum electrolytic capacitor prepared by the invention comprises the microporous layer and the base material layer, and the conductive graphite is attached to the microporous layer, so that the high-voltage alternating current impact resistance and the cycle performance of the aluminum electrolytic capacitor are effectively improved.

The present invention relates to a magnetic sensor and a current sensor, the magnetic sensor (30) having: an excitation coil (45) formed from a flexible substrate; and a field core (44) which extends in the axial direction of the field coil (45) and around which the field coil (45) is wound. When the flexible substrate deforms, the excitation core (44) is disposed in the flexible substrate such that at least a portion of the excitation core (44) can move in the tape length direction of the excitation core (44) with respect to the flexible substrate.

The invention relates to an overflow valve, a negative control overflow valve and a control valve. A negative control relief valve (10) according to an embodiment is provided with: a housing (2); and a relief valve body (20) which is attached to the housing (2) and through which hydraulic oil passes. The relief valve main body (20) has at least a first throttle section (43) and a second throttle section (55) that apply resistance to hydraulic oil passing through the relief valve main body (20).

The invention discloses a laminated aluminum electrolytic capacitor and a preparation method thereof. The preparation method comprises the following steps: S100, cutting an aluminum foil; s200, depositing on the surface of the aluminum foil through metal sputtering to form an aluminum oxide film; s300, the sputtered aluminum foil is subjected to multi-step heat treatment and quenching treatment; s400, depositing a conductive polymer on the aluminum oxide to serve as a cathode of the capacitor; s500, covering the conductive polymer with a graphite layer; s600, covering the graphite layer with a silver paste layer; s700, stacking a plurality of aluminum foils coated with the silver paste layers together to form a laminated capacitor structure; and S800, packaging and aging are carried out. The aluminum oxide film formed on the aluminum foil of the laminated aluminum electrolytic capacitor provided by the invention is uniform, flat and compact, the laminated aluminum electrolytic capacitor is small in leakage current and long in service life, and the leakage current of the laminated aluminum electrolytic capacitor cannot be obviously increased along with the increase of service time.

According to the oscillator circuit and the integrated circuit chip provided by the invention, by designing the zero-temperature current generation circuit, the first current with the temperature coefficient being zero can be provided for the interior of an oscillator, so that the working current of the circuit is not influenced by the temperature fundamentally, and the reference voltage which is not influenced by the temperature can be generated through the zero-temperature voltage generation circuit; the charge pump circuit can be used for generating a second voltage with a preset waveform, so that the second voltage is compared with the first voltage which is not influenced by the temperature, a comparison signal is generated at the comparator circuit, and further, the digital logic circuit performs logic operation processing on the comparison signal to generate an expected clock signal; therefore, the output of the clock signal which is not influenced by temperature is realized, and the temperature characteristic and the frequency stability of the clock signal are improved.

The transformer comprises a base, a slot is formed in the upper surface of the base, a magnetic core is fixedly connected to the inner wall of the slot, a primary copper foil winding is fixedly connected to the outer surface of the magnetic core, and a secondary copper foil winding is fixedly connected to the outer surface of the primary copper foil winding. According to the transformer good in temperature characteristic and beneficial to passing of the large current, the manufacturing method of the transformer comprises the steps that the magnetic core is fixed in the base, then 0.3 mm * 30 mm gum copper foil is used for closely winding the magnetic core for four circles to form the primary copper foil winding, then 0.1 mm * 200 P silk-covered wires are used for tightly winding the primary copper foil winding, and the secondary silk-covered wire winding is used for tightly winding the primary copper foil winding for four circles to form the transformer good in temperature characteristic and beneficial to passing of the large current. The primary winding is divided into two groups, each group is densely wound with a primary copper foil winding for 15 circles to form a secondary silk-covered wire winding, and the secondary silk-covered wire winding is covered with a shell to form the power supply boosting transformer, so that the primary winding is made of flat copper foil instead of conventional single or multiple copper wires, the temperature characteristic of the transformer is improved, and large current can conveniently pass through; therefore, the conversion efficiency of the transformer in the power supply equipment is improved.

The utility model discloses a converter, and especially relates to a novel voltage converter. Comprising a machine base, a machine shell is arranged on the machine base, a power line is arranged on one side of the machine base, socket board fixing pieces are symmetrically arranged on the machine shell, a machine body connecting and fixing piece is arranged at the top of the machine base, a transformer is arranged on the machine body connecting and fixing piece, sockets are arranged on the socket board fixing pieces, and a power line is arranged on the power line. The machine body connecting and fixing piece is connected with the machine base and the machine shell to improve the overall strength of the machine body, the power line is connected with the transformer to convert voltage and transmit the voltage to a socket on the socket board fixing piece, and the machine body connecting and fixing piece is hollow, so that the weight is reduced, and meanwhile heat dissipation is facilitated. As the coil is directly wound on the iron core, the magnetic flux path is more compact, the leakage flux is less, the ferrite material of the shell of the transformer has excellent temperature characteristics, the transformer can stably work in a high-temperature environment, the magnetic flux closing condition is good, the energy transmission efficiency is high, and the loss is small.

The invention discloses a distributed photovoltaic access distribution line protection method and device, and the method comprises the steps: collecting distribution line parameters, and building a multi-target distribution line protection fixed value setting model with the shortest protection fixed value time and the optimal sensitivity as targets; taking the multi-target distribution line protection setting value setting model as an improved hawk algorithm fitness function, and solving the model by using the improved hawk algorithm to obtain an optimal protection setting value; and the optimal protection constant value is embedded into the switch equipment, and distribution line relay protection is carried out. According to the method, the protection constant value adaptive to the current system can be automatically generated without knowing the fault voltage and current change characteristics of the system, and the method can be well suitable for the distributed photovoltaic access power distribution network. The reliability of the system is improved by improving the hawk algorithm, and the method has practical engineering significance. And a distribution line protection fixed value setting algorithm is embedded into the equipment, so that the integration level of the distribution equipment and the sensing capability of the distribution line are improved, and the operation reliability of the distribution network equipment is improved.

The invention relates to an elastic wave device which is characterized by comprising a supporting substrate, a dielectric layer, a piezoelectric substrate and a resonator, the dielectric layer is formed on the supporting substrate; the piezoelectric substrate is formed on the dielectric layer; the resonator includes an IDT electrode formed on a piezoelectric substrate; wherein the dielectric layer is provided with a stripe-shaped first acoustic impedance region, and the first acoustic impedance region is provided with a long side direction and a short side direction; and stripe-shaped second acoustic impedance regions which are alternately arranged with the first acoustic impedance regions, have a long-side direction and a short-side direction, and have an acoustic impedance different from that of the first acoustic impedance regions. According to the present application, it is possible to provide an elastic wave device which has good temperature characteristics and which further suppresses spurs, and a method for manufacturing the elastic wave device.

The invention relates to the field of switching converter design, and discloses a control method of an asymmetric half-bridge flyback converter. A clock signal is arranged on the secondary side of the converter, a primary side excitation current signal is simulated in real time, a driving control signal of a primary side switch tube is generated on the secondary side according to the clock signal and the simulated excitation current signal, and the driving control signal is transmitted to the primary side through a high-reliability signal isolator. According to the asymmetric half-bridge flyback converter, on and off of a primary side switching tube are controlled, output voltage stabilization and primary side peak current control are achieved, the problems that an existing optocoupler feedback control scheme is low in reliability, and output protection is not timely and accurate enough are effectively solved, and the asymmetric half-bridge flyback converter has higher reliability, better output protection performance and smaller size; and the application occasions of high reliability, high performance and small size can be simultaneously met.

The invention discloses a high-frequency wide-temperature low-power-consumption soft magnetic manganese-zinc ferrite material and a preparation method, and belongs to the technical field of manganese-zinc ferrites.The soft magnetic manganese-zinc ferrite material comprises main materials and auxiliary materials, the main materials comprise, by mole, 53-55 mol% of Fe2O3, 9-10 mol% of ZnO and the balance MnO; the auxiliary materials comprise the following raw materials in parts by million: 3500 to 5000 ppm of Co3O4, 500 to 2000 ppm of SnO2, 300 to 800 ppm of CaCO3, 20 to 100 ppm of SiO2, 500 to 2000 ppm of TiO2 and 200 to 500 ppm of Nb2O5. According to the invention, the problem of high power consumption at 25 DEG C to 140 DEG C under 300KHz and 100mT in the prior art is solved. The invention has excellent loss characteristics and temperature characteristics.

The invention provides a reference voltage source control circuit suitable for a micro-energy acquisition system and a control method of the reference voltage source control circuit, the control circuit comprises a reference voltage source, a low-leakage sampling and holding switch and a reusable logic unit, according to the working characteristics of the micro-energy acquisition system in a normal working mode and a standby mode, different control strategies are adopted for the voltage reference source, so that low power consumption of the voltage reference source is realized, that is, the working time of the reference voltage source is controlled according to control signals of a lower side tube and an upper side tube in a main circuit BOOST in a normal working mode; in the standby mode, the reference voltage source is controlled by multiplexing the MPPT clock, so that the average power consumption of the reference voltage source can be greatly reduced, and the efficiency of the micro energy acquisition system is improved. In addition, under the conditions that a large resistor is not adopted and the chip area is saved, the low power consumption and the good temperature characteristic of the reference voltage source are still achieved.

The present invention discloses a high-pixel panoramic optical system and a camera module, wherein the optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens which are sequentially distributed along the optical axis from the object plane to the imaging plane, wherein the object plane side of the first lens is convex, and the image plane side is concave; the object plane side of the second lens is convex, and the image plane side is concave; the object plane side of the third lens is convex, and the image plane side is concave; one of the object plane side and the image plane side of the fourth lens is convex, and the other is convex or flat; the object plane side of the fifth lens is convex or flat, and the image plane side is convex, or the object plane side is convex, and the image plane side is concave; the object plane side of the sixth lens is concave or convex, and the image plane side is concave; the object plane side of the seventh lens is convex, and the image plane side is concave. Based on a reasonable optical configuration, the present invention adopts a combination of seven lenses and a reflective element to realize an optical system and a camera module with high pixels, a large target surface, and a small volume.

The present invention discloses a small β detector for monitoring particulate matter based on MPPC, and its structure includes a plastic scintillator, a light guide, an MPPC, a circuit board, a housing, a shielding window, and a cable. The scintillator and the MPPC are coupled together by optical glue through the light guide; the side of the scintillator and the side of the light guide are both made with a reflective layer; the circuit board is integrated with a temperature compensation power supply circuit and a signal processing circuit; the housing includes an end cover, a main body, and a back cover, and the end cover and the front end of the main body are both provided with the shielding window. The present invention adopts a new type of semiconductor optoelectronic device MPPC, matches the β-type scintillator and the power supply and signal processing circuit suitable for MPPC, and realizes the counting detection of β rays; and by using the light guide, a larger effective detection area is realized when using an MPPC with a smaller effective photosensitive area, while ensuring a low background and high detection efficiency, which is very suitable for use in the fields of atmospheric dust particle monitoring, paper thickness measurement, etc.

The invention discloses a conformal dynamic installation method of a tail fiber in a portable optical communication comprehensive tester, and relates to the technical field of installation methods of tail fibers. The method comprises the following steps of system design and splitting, system structure design, optical device layout design, tail fiber coiling installation design, optical device installation and tail fiber coiling, wherein overall fiber coiling design is carried out according to the number of optical devices and the scale and length of tail fibers, and the tail fibers of the optical devices are coiled on an optical signal driving PCB, when the tail fiber is coiled, the radius of curvature is not less than 3cm, so that the coiled tail fiber is in a loose state and is fully contacted with the bottom of another PCB, and the installation part is incompletely locked by using a nylon cable tie. According to the method, the size and weight design parameters of the portable optical communication comprehensive test equipment can be reduced, and it is ensured that the optical characteristics of the portable optical communication comprehensive test equipment are not affected when the portable optical communication comprehensive test equipment is subjected to environment adaptability tests such as vibration and impact.

The present invention discloses a six-component annular wind tunnel balance, including a balance resistance measuring section, a balance cantilever connecting section for connecting a force measuring model or component is arranged on one side of the balance resistance measuring section, a balance fixed connecting section is arranged on the other side of the balance resistance measuring section, a balance front measuring section for force measurement is arranged between the balance resistance measuring section and the balance cantilever connecting section, and a balance rear measuring section for force measurement is arranged between the balance resistance measuring section and the balance fixed connecting section. The present invention breaks through the limitations of the traditional rod-type wind tunnel balance structure, adopts a four-sided symmetrical structure, has good symmetry of force deformation, strong anti-interference ability, high bending moment bearing capacity and good temperature characteristics, smaller deformation under the same output conditions, higher strength, and higher measurement accuracy, can improve the quality of wind tunnel tests, and has great engineering application value.

The application discloses a band gap reference circuit, a band gap reference generation method and a chip. The band gap reference circuit comprises a first resistor, a first PNP transistor and a second PNP transistor, a first current mirror unit, a first transistor, a second current mirror unit and a reference voltage generation unit. The first current mirror unit outputs a first current and a second current; the first transistor is used for generating a third current; the second current mirror unit proportionally copies the third current to generate a fourth current and a fifth current; and the reference voltage generation unit is used for generating a zero-temperature-coefficient reference voltage. According to the band gap reference circuit, the band gap reference generation method and the chip, NPN transistors are not used, so that a smaller number of masks and a smaller area are required, the application in a large-scale integrated circuit is more favorable, good temperature characteristics are simultaneously achieved, a stable reference voltage is maintained at high temperature, and the application in a high-temperature or high-power module in a system basic chip is suitable.

The application discloses a low dropout linear regulator circuit which is mutually started with a bandgap reference circuit, and comprises a pre-starting circuit, an operational amplifier, a first NMOS transistor, and a bandgap reference circuit; the same-phase input end of the operational amplifier is connected with the output end of the pre-starting circuit; the gate of the first NMOS transistor is connected with the output end of the operational amplifier, and the source thereof is communicated with the input end of the bandgap reference circuit, so that an initial output voltage is generated to pre-start the bandgap reference circuit; the output end of the bandgap reference circuit is communicated with the pre-starting circuit, and after pre-starting, the LDO circuit is restarted to obtain a final output voltage, and the mutual starting of the LDO circuit and the bandgap reference circuit is realized. The application solves the problems that the traditional LDO circuit cannot provide stable bias current by itself, and the load capacity and transient response performance of the traditional bandgap reference type LDO circuit are poor, adopts a special mutual starting mechanism, simplifies the pre-starting and shutdown mechanism, improves the load capacity and transient response performance of the LDO circuit, guarantees the stable output voltage, and ensures the normal work of other modules of the system.

Provided is a dielectric having a high dielectric constant in a temperature range of ‑50° C. to 350° C., and a dielectric constant change rate of 30% or less. An inorganic substance, characterized in that it contains an oxide crystal containing A and M (A is one or more of P, Ge and V, and M is one or more of Nb and Ta), and a dielectric constant of 500 or more. The oxide crystal is PNb 9 O 25 , P 2.5 Nb 18 O 50 and GeNb 9 O 25 ,GeNb 18 O 47 ,GeNb 19.144 O 50 、VNb 9 O 25 、VNb 9 O 24.9 ,PTa 9 O 25 , GeTa 9 O 25 、VTa 9 O 25 and one or more of their solid solutions.

This disclosure provides a multilayer ceramic capacitor and a method for manufacturing the same. The multilayer ceramic capacitor includes: a capacitor body comprising a dielectric layer and an inner electrode layer; and an outer electrode disposed on the outer surface of the capacitor body. The dielectric layer comprises a plurality of dielectric grains, at least one of which has a core-shell structure. The core-shell structure includes a core and a shell surrounding at least a portion of the core. The core comprises barium (Ba) and titanium (Ti), and the shell comprises zirconium (Zr) and calcium (Ca) and / or strontium (Sr).

The invention relates to a resonant inductor integrated transformer module, the resonant inductor integrated transformer module according to the invention comprising: a transformer (10); and resonant inductors (210, 310) which are spiral coils, are formed on one side of the transformer (10), are connected to the coils (110, 120) constituting the transformer (10), and play a role in the capacitance and resonance of the transformer (10) itself.

This application provides a battery screening method, system, electronic device, and computer-readable storage medium, relating to the field of battery screening. The battery screening method includes: after placing a fully charged target battery in a static state for a first preset time period, measuring a first electrical parameter of the target battery; after the target battery's temperature drops to a target temperature and is placed in a static state for a second preset time period, measuring a second electrical parameter of the target battery; after discharging the target battery to a preset charge at a target temperature, measuring a third electrical parameter of the target battery after discharging to the preset charge; after discharging the target battery to the preset charge at the target temperature and restoring it to the temperature at which the first electrical parameter was measured, measuring a fourth parameter of the target battery; and determining whether the target battery meets the qualification requirements based on the electrical parameters. Using this battery screening method, battery consistency can be accurately and efficiently determined, and battery quality can be effectively checked and differentiated.

The present invention proposes a method for manufacturing a piezoelectric oxide single crystal substrate, including: preparing lithium-rich polycrystalline powder, mixing lithium carbonate and metal oxide, performing high-temperature solid-phase reaction, and then crushing to prepare lithium-rich polycrystalline powder, wherein the metal element in the metal oxide is the same as the metal element in the piezoelectric oxide single crystal substrate, the lithium in the lithium-rich polycrystalline powder and the metal have a first stoichiometric ratio, and the lithium in the piezoelectric oxide single crystal substrate and the metal have a second stoichiometric ratio; preparing a reduction sheet, mixing the lithium-rich polycrystalline powder and the reducing powder according to a preset ratio, and pressing the sheet to prepare a first reduction sheet and a second reduction sheet; performing a reduction treatment, placing the first reduction sheet, the piezoelectric oxide single crystal substrate, and the second reduction sheet on a bracket in sequence, and performing a high-temperature reduction treatment for a preset time to generate a piezoelectric oxide single crystal substrate with a pseudo-stoichiometric surface composition. In this way, the polarization structure of the piezoelectric oxide single crystal substrate can be maintained, and the piezoelectricity of the substrate can be improved.

The utility model relates to crystal heat preservation technical field provides a crystal heat preservation structure spare, including base, the side of base is equipped with square hole, hollow groove is equipped with on the base, the base is equipped with the tin cream welding groove on the outside of hollow groove, the base is equipped with first connecting groove on the outside of tin cream welding groove, the top of base is provided with heat preservation lid, second connecting groove is equipped with on the heat preservation lid, the surface of base and heat preservation lid all is provided with protective layer. The utility model through to the crystal increases a base and the heat preservation of lid, has improved the temperature characteristic, frequency stability, phase noise etc. of product, makes the each item of product index technology better, the surface of base and heat preservation lid is coated protective layer, the protective layer can play certain protection function to base and heat preservation lid, enhances the wear resistance, corrosion resistance, high temperature resistance and antifouling performance of base and heat preservation lid, improves its use effect.

The invention provides a large-aperture high-definition optical system and a camera module applying the same, the large-aperture high-definition optical system is mainly composed of six lenses, the object plane side of the first lens is a convex surface, the image plane side is a concave surface, and the focal power of the first lens is negative; the object plane side of the second lens is a concave surface, the image plane side is a convex surface, and the focal power is negative; the object plane side and the image plane side of the third lens are convex surfaces, and the focal power of the third lens is positive; the object plane side and the image plane side of the fourth lens are convex surfaces, and the focal power of the fourth lens is positive; the object plane side of the fifth lens is a concave surface, the image plane side of the fifth lens is a convex or concave surface, and the focal power of the fifth lens is negative; the object surface side of the sixth lens is a convex surface, the image surface side of the sixth lens is a convex or concave surface, the focal power is positive, the number of lenses is reasonable, the structure is simple, the imaging quality of the optical system is improved by reasonably distributing the focal power of the lenses and optimizing the aberration of the lens, and the characteristics of large aperture, high resolution, excellent temperature characteristic, small size and short total length are considered. The method has higher competitiveness in the field of vehicle-mounted or security and protection.