155 results about "Glass laser" patented technology

The invention belongs to the technical field of laser processing, and particularly relates to a special-shaped curved glass laser cutting track planning method. According to the method, the instantaneous thermal effect and the historical thermal accumulation effect are subjected to coupling calculation, high-precision prediction and compensation of thermal deformation in the laser cutting process are achieved, the accuracy of the cutting track is improved, contour deviation caused by thermal deformation is avoided, and the geometric precision is improved; according to the local geometric complexity of the special-shaped curved glass, regions are divided, and differential virtual scanning layers and scanning modes are matched, so that the dynamic balance of efficiency and precision is guaranteed, the processing quality of regions with high curvature, thin walls and the like is guaranteed, the cutting speed of flat regions is increased, and the processing period is shortened; by monitoring the temperature and feeding back actual thermal historical parameters during cutting, model parameters are reversely optimized by using contour precision data after cutting is completed, so that robustness and stability are enhanced, and the yield and process reliability of laser cutting of the special-shaped curved glass are improved.

The invention relates to the technical field of glass welding, in particular to a clamping device for metal-glass laser welding and a welding method. The device comprises a bottom plate, a cover frame and supporting columns connecting the bottom plate and the cover frame, and a lifting part is formed between the cover frame and the bottom plate. A mechanical lifting assembly with an adjusting rocker and a graduated scale is installed on the bottom plate in the lifting part, the lower end is connected with the bottom plate, and the upper end is connected with the machining table to drive the machining table to ascend and descend. And the center of the cover frame is provided with a quartz glass pressing plate plated with a magnesium fluoride antireflection film. A cylindrical metal mounting base coaxial with the glass pressing plate is arranged on the machining table and used for mounting metal to be welded. During welding, the adjusting rocker is rocked to lift the machining table so that to-be-welded glass can make contact with the glass pressing plate, and optical contact is achieved by observing the situation that an interface Newton ring disappears from appearing; the whole clamping device is moved to a laser machining platform, and welding is conducted through a glass pressing plate; and after completion, the machining table is lowered to disassemble the weldment.

The invention relates to the technical field of laser internal engraving, and discloses a crystal glass laser internal engraving machine based on a positioning structure, which comprises an air floating platform, the air floating platform is arranged on a working table of the laser internal engraving machine, the air floating platform comprises a base, the base is provided with a suspension seat, the suspension seat is of a disc-shaped cavity structure, and the positioning structure is arranged on the suspension seat. The suspension seat is connected with a positioning mechanism, and the base is connected with a balance mechanism which can be used for enabling the suspension seat to be rapidly balanced after suspension. The crystal glass laser internal engraving machine based on the positioning structure can effectively solve the problems that in the prior art, due to the fact that a traditional positioning mode cannot rapidly and accurately place an element at an ideal engraving position, the focusing process of the laser internal engraving machine is tedious and time-consuming, and when the traditional laser internal engraving machine works, the working efficiency is high. Vibration generated by a mechanical transmission system and the ground can be transmitted to a working table, so that the circular crystal glass element generates tiny vibration, and the conditions of deviation, blurring and the like of a laser internally-carved pattern are further caused.

The invention provides a control method and system for glass laser marking, and relates to the field of intelligent control or adjusting systems in industrial machining.The method comprises the steps that three-dimensional height data of all machining points on the working face of a machining table is obtained, and a three-dimensional height data set is formed; generating a laser head height compensation data set of each machining position of the machining table based on the three-dimensional height distribution data of the overall machining table; acquiring information of to-be-marked glass and geometric data of a to-be-marked area on the to-be-marked glass; acquiring height compensation data of the marking area according to the to-be-marked glass information and the geometric data of the marking area, and generating a marking area path plan; according to the scheme, three-dimensional height data acquisition of a machining table is taken as a core, a marking area path plan for controlling operation of a marking machine is obtained on the basis of the data, a marking area path is adjusted through a height compensation data set, a final area path scheme is generated, and the movement of a laser head is dynamically adjusted by adopting an intelligent control technology.

The invention discloses a device for cutting daily glass through laser. The device comprises a laser assembly, a clamping jaw assembly and a product supporting assembly. The product supporting assembly is used for supporting daily glass, the clamping jaw assembly is located over the product supporting assembly and clamps the daily glass on the product supporting assembly, the laser assembly is located on one side of the clamping jaw assembly, the laser assembly points to the daily glass, and the daily glass is cut through laser. According to the invention, on the aspect of technical principle, an advanced laser technology and a high-precision control system are fused, the limitation of a traditional cracking method is broken through, and fine processing of the cracking of the glassware is realized by accurately regulating and controlling laser energy and pulse parameters.

The utility model discloses a borosilicate glass laser-beam drilling machine, which relates to the technical field of borosilicate glass processing and comprises a base. The bottom of the bottom plate is fixedly connected with the top of the base; the bottom of the positioning assembly is fixedly connected with the top of the bottom plate, and the positioning assembly is used for positioning borosilicate glass; the outer side of the fixing assembly is fixedly connected with the inner side of the positioning assembly, and the fixing assembly is used for fixing borosilicate glass; the bottom of the shell is fixedly connected with the two sides of the bottom plate; and the top of the laser drilling machine body is fixedly connected with the top of the inner cavity of the shell. According to the device, the fixing assembly is arranged, so that glass is conveniently fixed, the working efficiency is improved, the positioning assembly is arranged, the position of the glass is adjusted, the glass does not need to be disassembled and reinstalled, and the glass punching position is conveniently changed.

A method of laser bonding glass to metal foil includes contacting a first glass substrate with a first metal foil to create a first contact location; directing a laser beam on the first contact location to bond the first glass substrate to the first metal foil; contacting a second glass substrate with a second metal foil to create a second contact location; and directing the laser beam on the second contact location to bond the second glass substrate to the second metal foil, wherein the first metal foil and the second metal foil each have a thickness from 5 μm to 100 μm, and wherein the laser beam comprises a pulsed laser comprising: a pulse energy from 2.8 μJ to 1000 μJ; and a wavelength such that the first and second glass substrates are substantially transparent to the wavelength.

The invention relates to the technical field of intelligent control, and discloses an intelligent control system and method for a crystal glass laser internal engraving machine. The method comprises the following steps: acquiring three-dimensional point cloud data of a crystal glass workpiece, extracting a material basic feature vector, and inputting the material basic feature vector into an axial self-crossover attention module for three-dimensional space feature association to obtain a three-dimensional space state map; fusing the acoustic emission signal, the light scattering signal and the temperature signal based on the three-dimensional space state map to perform to-be-excited state discrimination, and determining a to-be-excited area; and adjusting the laser power, the pulse frequency and the focusing depth according to the to-be-excited region to obtain a laser parameter combination, and performing position trajectory and control input optimization on the plurality of laser heads to generate an execution instruction of each laser head. The laser power, the pulse frequency and the focusing depth can be adaptively adjusted according to the recognition result of the to-be-excited area, and then the machining precision and stability of the crystal glass laser internal engraving machine are improved.

The invention discloses an external cracking mechanism and glass laser cutting equipment comprising the same, and relates to the technical field of glass cutting, the external cracking mechanism comprises a triangular mounting table, the middle of the triangular mounting table is fixedly connected with a first servo graduator, the output end of the first servo graduator is fixedly connected with three evenly-distributed station discs, and the output end of the first servo graduator is fixedly connected with a second servo graduator; and positioning assemblies used for positioning glass are arranged on the station discs, and second servo graduators are arranged at the three end corners of the triangular mounting table correspondingly. According to the glass feeding and discharging device, the grabbing hand can be matched with the feeding table to complete glass taking during working, matched with the receiving table to complete glass discharging and matched with the receiving table to complete glass splitting treatment, so that manual taking and discharging are not needed during glass feeding and discharging, and the labor intensity of workers is greatly reduced.

The utility model relates to the technical field of glass laser coding machines, and discloses a clamping device of a glass laser coding machine, which solves the problem that the glass laser coding machine is not easy to stably clamp glass when clamping the glass, and comprises a processing table, the upper surface of the processing table is fixedly connected with a mounting frame, and the mounting frame is fixedly connected with the glass laser coding machine. A laser machining mechanism used for laser machining is arranged on one side of the mounting frame, a clamping mechanism used for clamping glass is arranged on the upper surface of the machining table and comprises a motor A fixedly connected to one side of the machining table, the output end of the motor A is fixedly connected with a double-threaded rod, and the outer side of the double-threaded rod is in threaded connection with a connecting plate. The upper surface of each connecting plate is fixedly connected with a clamping plate, one side of each clamping plate is fixedly connected with a buffering pad, a sliding groove A is formed in the upper surface of the machining table, the connecting plates are connected into the sliding grooves A in a sliding mode, the number of the connecting plates is two, the two connecting plates are symmetrically arranged, and the purpose of stably and firmly clamping glass is achieved.

The utility model discloses a pulse width adaptive delay modulation circuit suitable for an erbium glass laser, which comprises an erbium glass laser, an input signal shaping circuit, an optical signal detection shaping circuit, a delay trigger circuit and a logic control output circuit, the input signal shaping circuit receives and shapes an external input signal and then outputs a driving signal to the logic control output circuit; the optical signal detection shaping circuit collects an optical signal, shapes the optical signal into a digital signal and transmits the digital signal to the delay trigger circuit, and the delay trigger circuit delays the received signal and transmits the signal to the logic control circuit; and the logic control circuit performs logic operation on the received two paths of signals and outputs a final driving signal to the erbium glass laser to form closed-loop control. According to the utility model, the light emitting condition of the erbium glass laser can be simply and effectively identified, a signal output by the input signal shaping circuit and a signal shaped during light emitting of the erbium glass laser are logically processed and then a driving signal is output, self-adaptive judgment control is realized, complex operation is not needed, the applicability of the driving circuit is improved, and the cost is reduced. And the driving application of the erbium glass laser is greatly simplified.

The utility model discloses a cutting device for blue light glass processing belongs to blue light glass processing technical field, including glass laser cutting machine and the linear module of arrangement on glass laser cutting machine still includes the material table for placing blue light glass of arrangement on the sliding block of linear module, the suction structure for sucking the glass chippings remaining on the material table of arrangement on glass laser cutting machine, and the suction structure includes the waste bin of arrangement on glass laser cutting machine one side, the telescopic pipe of arrangement on the waste bin and with waste bin intercommunication. The utility model, after the blue light glass cutting of material table is completed, can utilize telescopic pipe suction chippings residue remaining on the material table through the opening of suction fan, and through the horizontal or vertical push of slide seat no.

The utility model discloses a glass laser cutting dust removal and waste separation device which comprises a dust collection mechanism, a dust removal mechanism and a waste separation mechanism, the dust collection mechanism comprises two collection discs, and a plurality of blanking holes are axially arrayed in the collection discs; the pumping and discharging mechanism comprises material falling pipelines which are vertically and fixedly connected to the bottom of the collecting disc, a through hole is formed in the center of the collecting disc, the material falling pipelines are fixed to the bottom of the through hole, the side walls of the material falling pipelines are vertically and fixedly communicated with dust pumping pipelines, exhaust fans are installed on the two dust pumping pipelines, and the outlet ends of the exhaust fans are communicated with the main pipeline; the waste material collecting mechanism comprises a waste material bin, a material bin drawer is slidably connected into the waste material bin, and the bottom end of the material falling pipeline communicates with the waste material bin; a filter element is installed at the end, close to the discharging pipeline, of the dust suction pipeline. According to the utility model, the suction effect is generated through the suction mechanism, and dust and waste are collected through the collecting tray and then are separated through the filter element for respective treatment.

The application relates to a glass laser film removing device for hollow glass production, and belongs to the technical field of hollow glass production.The glass laser film removing device comprises a base, a laser generator for removing a film layer on the surface of glass, a distance measuring mechanism installed on the laser generator and used for detecting the distance between the laser generator and the glass, and a driving mechanism, wherein the laser generator is installed on the driving mechanism, and the driving mechanism is used for adjusting the position of the laser generator; the glass laser film removing device has the beneficial effect of improving the film removing quality of the glass laser film removing device.

The invention discloses a cover plate glass, a laser drilling and hole chamfering processing method and a pretreatment device thereof, and the method comprises the following steps: carrying out laser modification treatment on glass by using a laser profiling light beam, and forming a modified contour surface consistent with the shape of a hole and a chamfer thereof in the glass, the material enclosed by the modified contour surface is a waste block needing to be removed; laser grooving treatment is conducted on the waste block through laser, and a drainage groove extending towards the interior of the glass till the drainage groove is close to the modified contour surface is formed; placing the grooved glass in an etching solution, wherein the etching solution permeates into the drainage groove to etch to the modified contour surface and then etches along the modified contour surface; the etched glass is subjected to splitting treatment, and the waste blocks are ejected out, so that the holes and the chamfers of the holes are formed; the device is flexible and controllable, the machining efficiency is improved, the machining precision is improved, and the machining requirements of chamfers of different shapes can be met.

The invention belongs to the related technical field of micro light emitting diode assembly, and discloses a laser-driven micro LED chip mass transfer device and a preparation method and application thereof, the device comprises a transfer stamp, the transfer stamp comprises glass, a laser sensitive layer, a heat absorption layer and a cavity layer, the glass, the laser sensitive layer and the cavity layer are sequentially connected, a through groove is formed in the laser sensitive layer, the heat absorption layer is arranged in the through groove and connected with the groove wall, and heat homogenization can be achieved through the anisotropic heat conduction characteristic of the heat absorption layer when laser and a chip are subjected to offset irradiation; a plurality of cavities arranged at intervals are formed in the side, away from the glass, of the cavity layer. The heating layer is arranged, photo-thermal conversion is achieved through the heating layer, chip transfer is achieved through the heat effect instead of laser ablation, repeated utilization (namely reversible transfer of the chip) of the transfer seal can be achieved, and therefore the time for repeatedly manufacturing the transfer seal is shortened.

Provided is a glass material which has a low linear thermal expansion coefficient and which can be used more stably as a laser medium. The glass is characterized by containing, in terms of mol%, 45%-85% of SiO2, 3%-23% of Al2O3, 0%-13% of B2O3, 0%-5% of Li2O, and 0.01%-11% of Ln2O3 (Ln is at least one selected from Ce, Nd, Yb, Er, Pr, Sm, Eu, Tb, Dy, Ho, and Tm). The glass is preferably used as a wavelength conversion member 26 of a laser oscillation device 2 that extracts laser light by emitting excitation light L from an excitation light source 20. The wavelength conversion member 26 is disposed between a resonator 22 and a resonator 24.

The invention relates to the technical field of glass laser processing, and discloses a laser processing method for making a black mark on a glass surface, which comprises the following steps: making a black mark line on the glass surface as visual positioning to carry out marking test and observe the marking effect; based on the marking test, obtaining laser data of the laser beam, obtaining a test mark line width and a preset black mark line width, obtaining a test expansion ratio, analyzing based on the test expansion ratio to obtain a test deviation value and a deviation ratio, and performing preliminary adjustment; based on the preliminary adjustment, obtaining the line width of the black mark on the glass, analyzing to obtain a processing expansion ratio, judging whether the marking effect of laser processing is qualified or not according to the obtained processing expansion ratio, generating different signals, and based on the unqualified signals, obtaining the laser power and the laser pulse width of the optical fiber laser; and an energy density value is obtained based on analysis of the obtained processing expansion ratio, and the laser power and the laser pulse width of the fiber laser are adjusted based on the obtained energy density value.

The utility model provides a large-format glass laser cutting machine, which relates to the technical field of glass cutting and comprises a frame body, a cutting moving mechanism and a laser component are arranged on the frame body, and the laser component comprises a laser cutting head. The cutting moving mechanism comprises an X-axis linear motor movement module, the X-axis linear motor movement module is connected with a Z-axis servo motor movement module in a sliding mode, the laser cutting head is connected to the Z-axis servo motor movement module, and the two ends of the X-axis linear motor movement module are connected with Y-axis linear motor movement modules in a sliding mode. The laser cutting device has the advantages that the laser cutting head is driven by the cutting moving mechanism to be adjusted in the X-axis direction, the Y-axis direction and the Z-axis direction, the adjusting flexibility is high, the laser cutting head can cut various positions, the distances between the belt conveying assemblies are the same, and when large-breadth glass is conveyed, the conveying efficiency is greatly improved. The multiple belt conveying assemblies can support the glass from multiple points, the weight of the glass is evenly shared, and the flatness of the glass in the conveying process is guaranteed.

The invention discloses a glass trepanning method based on laser. The glass trepanning method comprises the following steps: S1, cleaning a material; s2, a coating is arranged; s3, removing the coating; s4, laser-induced modification; s5, chemically etching the modified layer; s6, removing the whole coating layer; and S7, cleaning and drying. According to the invention, through the double-path laser system and the mode of arranging the protective layer in cooperation with the glass laser, very precise and efficient laser trepanning treatment can be effectively carried out on the set position on the glass substrate, the thinning of the glass during etching is avoided, the preset thickness of the glass substrate can be effectively reduced under the condition of ensuring the laser trepanning effect, and the production efficiency of the glass substrate is improved. However, the thin glass is easier to realize trepanning, so that the etching time is shortened, and the efficiency is improved.

The invention relates to the technical field of laser cutting, and particularly discloses a glass laser cutting method without a polishing process, which comprises the following steps of: cleaning glass powder on the surface of a milled and ground workpiece, drying, clamping the workpiece, immersing the workpiece into a station of a laser cutting machine, and cutting the workpiece by using a laser cutting machine. Auxiliary liquid mixed with the laser cutting machine is arranged in a station of the laser cutting machine, the laser cutting machine is assisted to conduct laser cutting on a workpiece which is not subjected to a traditional polishing procedure, and the cutting task can be accurately completed; according to the method, the workpiece can be penetrated by laser to be cut without being polished by a polishing solution, and the polishing procedure, additional products in the polishing procedure and the excessive labor cost are omitted; by adopting the method, the production cost can be effectively reduced, the efficiency is greatly improved, and the method is environment-friendly.

This item is a slide glass laser printer.

The utility model relates to the technical field of glass laser cutting equipment, in particular to a through hole device and a cutting system. The through hole device comprises a supporting cross beam and air guide equipment, the supporting cross beam is arranged on the downstream side of the glass laser cutting equipment, the air guide equipment is connected to the supporting cross beam, the air guide equipment is provided with an air nozzle, the air nozzle is configured to be aligned to the position where glass hole slag does not naturally fall off, the air guide equipment is connected with an air bin, and the air bin is connected with the supporting cross beam. The gas bin can convey compressed gas to the gas guide equipment, and the compressed gas is blown out from the gas nozzle so as to blow off glass hole slag. The cutting system comprises the through hole device. According to the through hole device and the cutting system, glass hole slag is blown off in a non-contact mode, the production quality of glass can be improved, the overall size of the through hole device is small, and the occupied area of the cutting system can be reduced.

The present application relates to glass processing equipment technical field, disclose a kind of special-shaped glass laser cutting processing device and control system, including shell, cutting table is installed in shell top, mobile mechanism is provided on shell, and cutting operation piece is connected on mobile mechanism;Conveying mechanism for conveying glass is provided in shell bottom, waste separation zone is provided in one side of shell top, waste frame is provided below waste separation zone;Cutting operation piece includes laser cutting head and flexible pressing cover, spring and ball are provided inside flexible pressing cover;Execution component is provided in waste separation zone, and multiple transmission belts with gap are provided in side edge.This application maintains cutting focal length stable by spring telescopic compensation glass fluctuation;Temperature difference is formed by execution component cold and hot intervention, waste is separated by thermal stress;Waste falls into waste frame by gap, finished product is output by transmission belt, and complete diversion.

The utility model discloses laser drilling equipment for photovoltaic glass, belongs to the related technical field of photovoltaic glass processing, and aims to solve the problem that in the prior art, when the photovoltaic glass is drilled, generated thermal stress may cause microcracks to the wall of a hole. The microcracks can reduce the strength of the glass and prolong the service life of the glass, and in the subsequent use process, the microcracks can be possibly expanded under the action of stress or environmental factors, and finally the glass is broken. The novel laser drilling equipment comprises a workbench, an electric telescopic rod, a lifting plate and two heating plates, and the lower end of the lifting plate is fixedly connected with the two heating plates. Through the electric telescopic rod, the heating plate and the lifting plate, due to the fact that the lifting plate is made of heat conduction materials such as copper, the temperature of the lifting plate can be increased through the heating plate, the situation that the service life of photovoltaic glass is shortened due to microcracks in the follow-up use process is avoided, and the working quality of the punching equipment is improved.

The utility model discloses a smoke dust purification device for conducting film glass laser engraving. The smoke dust purification device comprises a box body, a cylindrical filter element, a filter plate and a centrifugal fan, wherein the cylindrical filter element, the filter plate and the centrifugal fan are arranged in the box body; an air inlet is formed in a front end plate of the box body, the inner end of the cylindrical filter element is of an opening structure, the outer end of the cylindrical filter element is of a closed structure, the inner end of the cylindrical filter element is connected to a vertical mounting plate in the box body, and an opening in the inner end of the cylindrical filter element is communicated with an opening in the vertical mounting plate; the filter plate and the centrifugal fan are vertically arranged in the box body from front to back and located between the vertical mounting plate and the rear end plate of the box body, an air outlet is formed in the rear end of the box body, and the air outlet end of the centrifugal fan communicates with the air outlet in the box body. The smoke dust filtering device is simple in structure, low in manufacturing cost and low in noise, and meets the smoke dust filtering requirement in the laser engraving process of the conductive film glass.

This utility model discloses a positioning device for laser engraving of shower glass, including a mounting base and two mounting boxes on both sides. A conveyor belt is installed inside the mounting base, and a positioning component is installed inside each mounting box. The positioning component includes a sliding column with a spring at its bottom and a limiting member at the bottom of the spring. Inclined grooves are provided on both sides inside the mounting boxes. In this utility model, the sliding column is pushed by electric push rods on both sides. When the limiting member contacts the conveyor belt, it moves inward due to the spring contraction, thus fixing both sides of the shower glass and completing the positioning. Shower glass to be laser engraved is then placed on one side of the conveyor belt. After laser engraving, the shower glass is conveyed outward, while the shower glass on one side of the conveyor belt is conveyed to the bottom of the laser engraving device, allowing for rapid laser engraving and increasing efficiency.

This invention discloses a fully automatic glass laser forming machine, comprising a frame, a cutting mechanism, a piercing mechanism, and a cleaving mechanism. The cutting mechanism includes a first conveyor belt, a first moving component, and a first laser head. The first conveyor belt transports glass, and the first moving component drives the first laser head to move. The piercing mechanism includes a second moving component, a second laser head, a driving component, and multiple second conveyor belts. The second moving component drives the second laser head to move, the second conveyor belts transport glass, and the driving component drives the second conveyor belts to move. The cleaving mechanism includes a third moving component, a third laser head, and multiple conveyor rollers. The multiple conveyor rollers transport glass, and the third moving component drives the third laser head to move. A waste conveyor belt is located below the piercing mechanism. This fully automatic glass laser forming machine enables automated glass processing, improving processing efficiency and enhancing equipment reliability.

The utility model discloses an astronaut modeling light device, which belongs to the related technical field of laser illumination and comprises a stainless steel plastic spraying shell, curved glass, a reflecting mirror, an electric holder, a cooling fan and a laser transmitter. The reflecting mirror and the electric holder are located at the head position of the stainless steel plastic spraying shell, laser emitted by the laser emitter is reflected to the curved glass through the reflecting mirror, the laser emitter is arranged in the stainless steel plastic spraying shell, the problem that the laser emitter is exposed outside is solved, the concealment of the laser emitter is achieved, and the laser emitter is convenient to use. The attractiveness and the ornamental value are increased, and the attractiveness and the practicability are combined; meanwhile, safe use of the laser transmitter is guaranteed, and man-made damage is reduced; the holographic laser device is attractive in appearance, has ornamental value, has more science and technology feeling for the performance holographic laser, can present varied images, generates a shocking visual effect, and integrally integrates practicability and decorative attractiveness into a whole.

The utility model discloses a hot stamping glass laser composite film which comprises a base layer, an adhesive layer, a hot stamping layer and a laser layer and further comprises a sound insulation mechanism, the sound insulation mechanism is arranged on the outer wall of the bottom of the base layer, a sound absorption layer is connected to the outer wall of the bottom of the base layer, a plurality of sound absorption holes are formed in the outer wall of the top of the sound absorption layer, and the sound absorption holes are formed in the outer wall of the bottom of the sound absorption layer. The sound absorption layer is arranged on the outer wall of the bottom of the laser layer, the supporting layer is installed in the middle of the sound absorption layer, the sound absorption layer is made of mineral fiber materials, the supporting layer is of a net structure and is made of carbon fiber materials, and the hot stamping layer is arranged on the outer wall of the bottom of the laser layer. The hot glass laser composite film disclosed by the utility model has the effects of improving the sound insulation efficiency and the environmental protection performance.