Research On Laser Thickness Measuring Instrument For Film

The surface of battery need to be coated with a layer of foil(Copper or Aluminum)，namely current collector. Its function is to collect the electric current which generated by thebattery active materials together to form strong electric current output. The thickness of filmis an important factor which will affect the quality of products. If the thickness of film is toothin，the adhesion force to collect active materials will reduce. If the thickness of film is toothick，it will increase the internal resistance of battery，lead to the attenuation of batterycapacity and cause the waste in economy. And if the thickness of film is not uniform or notreach the requirements，will have a negative impact on battery capacity and consistency.Therefore，real-time detection of the thickness of film is important.According to the requirements of user， based on the technology of thicknessmeasurement by laser，we design the laser thickness measuring instrument for film. Throughthis instrument，can solve the problem of non-contact monitoring of the thickness of filmwhich arise in the process of production. The whole thickness measuring system includes twoparts：mechanical system，measuring and control system.Mechanical system mainly includes four parts: the whole frame，self-calibration devicefor measuring head by laser，transfer device for film coated by foil，measuring device for film.The whole frame provide work platform for instrument. Through the self-calibration devicefor measuring head by laser，can realize the calibration of laser’s coaxial tolerance andmeasuring head by laser. Transfer device can finish the rewind of film coated by foil.Measuring device for film will complete the thickness measurement.According to the composition，the measuring and control system can be divided into twoparts：hardware and software. The hardware of measuring and control system can be dividedinto two parts：the hardware of measuring system and the hardware of motion control system.Industrial PC is the key part of the hardware of measuring system. The hardware of motioncontrol system mainly includes the motion control cards. The industrial PC receives signals，completes the processing of data and sends out the motion commands. The motioncontrol cards receive the commands and then execute the corresponding action. The softwareMeasuring and control system contains data processing program and motion contro l program.The data processing program completes the analysis，processing and storage of measurementsignal and the motion control program controls mechanical motion.Experimental results show that the precision of repeated measurement of the machine is±0.5μm. The requirements of the customers satisfied.