48results about How to "Improve focus characteristics" patented technology

A gradient-index lens is structured by a multilayer film that includes therein a plurality of layers each of which has different refractive index and layer thickness from the other.

The invention relates to a method for measuring frequency response function of a vibration structure in loud-noise environment, comprising the following steps: a linear swept-frequency signal is adopted as an excitation signal and acceleration response signals of the structure vibration is filtered in a fractional order Fourier domain by fractional order Fourier transformation, so that effect of noise in non-stationary process can be lessened, and measuring accuracy of the frequency response function is improved. Simultaneously, in the method, two groups of experiment signal data are expressed as one group of plural experiment signal data so as to avoid effect of superposition of two signal components, and only one-time filtering is needed to finish noise removal treatment of the two groups of the experiment signal data so as to improve noise removal effect and operating speed.

The invention provides a method for determining multipath time delay and Doppler frequency shift in an underwater acoustic channel, and relates to an underwater acoustic channel estimation method. A transmitting terminal generates N linear frequency modulation signals and the signals are linearly superposed to serve as channel estimation signals, and the channel estimation signals are converted into sound waves through a transmitting transducer to be spread in ocean acoustic channels; a receiving terminal receives acoustical signals spread in the ocean acoustic channels through a receiving transducer and converts the acoustical signals into electrical signals, and digital signals are obtained through pre-amplification, smoothing and analog/digital conversion; fractional Fourier transformation corresponding to focusing orders is conducted on the digital signals and local reference signals N times and N peak position offset quantities with different orders are obtained through comparison; the multipath time delay and the Doppler frequency shift of all paths of the channel are determined by the adoption of a time-delay and frequency-shift joint estimation method according to the peak position offset quantities. By means of the method, the computational process is simple and system overhead is saved.

The invention relates to a semiconductor laser glue solidification device and an application method thereof. The device comprises a semiconductor laser light source, an optical beam shaping system, an optical beam transmission system, an optical beam scanning system, an optical focusing system, and the like. The application method comprises the following steps of generating the laser light source through a semiconductor laser diode, carrying out the shaping transmission on the semiconductor laser light source by adopting the optical beam shaping system and the optical beam transmission system, focusing the semiconductor laser light source to the appropriate spot size and working position through the optical focusing system, and irradiating a workpiece or glue so that the temperature of the glue rises rapidly and the glue is solidified rapidly. The invention can carry out partial or fixed-point heating on the workpiece, has the advantages of rapid solidification, low cost, high energy utilization ratio, and the like and can be widely applied to the field of heating solidification of various glues.

The invention discloses a self-adaptive closed-loop control flying optical path mechanism and a control method thereof. The flying optical path mechanism comprises a laser, a flying optical path and a drive control system; the flying optical path comprises a flying focusing head and a binocular system; the binocular system comprises an eyepiece and an object lens; the flying focusing head comprises a plane mirror and a focusing mirror; the laser and the eyepiece are relatively fixedly arranged; light beams which are emitted by the laser are reflected to the focusing mirror for focusing by sequentially passing through the eyepiece and the object lens; and the drive control system can drive the object lens and the focusing mirror to carry out the reciprocating motion along an optical axial line according to the position signals of the flying focusing head and the focusing mirror. The flying optical path mechanism has high-performance self-adaptability, and can improve the focusing feature of the flying light beams, accurately and reliably compensate the change of the depth of focus of a laser focus point and obtain the set focus size and the depth of the focus through controlling the positions of the beam expanding object lens and the focusing mirror along with the change of the flying distance; furthermore, the method is simple and reliable, a complicated control unit of a deformable mirror is eliminated, the structure is simple, and the cost is low.

A scanning mirror includes a mirror base and a reflective film formed on the mirror base. The mirror base is formed from a non-metallic material having a specific rigidity, determined by Young's modulus (GPa) and density (g/cm³), of at least 100 GPa·cm³/g.

A zoom lens including a first lens unit exhibiting a positive refractive power and always being statically positioned along an optical axis when a power of the zoom lens is varied or the focusing is conducted and including a reflective optical element for bending an optical path, a second lens unit exhibiting a negative refractive power and including a negative lens, a negative lens and a positive lens, along the optical axis in this order from an object side, a third lens unit exhibiting a positive refractive power, a fourth lens unit exhibiting a positive refractive power, and including at least two positive lenses, and a fifth lens unit exhibiting a negative refractive power, wherein the second lens unit, the fourth lens unit and the fifth lens unit are moved for varying the power of the zoom lens.

A pair of magnets of which magnetizing direction differs from each other in the horizontal direction (X axis) are arranged at upper and lower portions of a funnel-side opening portion of a deflection yoke. The pair of magnets are held and fixed to a coil support body which supports horizontal deflection coils in a state where the magnets are embedded in the coil support body. In a projection type cathode ray tube of a single electron beam method, a locus of an electric beam which receives the deflection distortion is corrected so as to correct an electron beam shape on a screen to an approximately circular shape whereby a focusing performance of a display image on a screen is enhanced.

A method corrects deflection defocusing in a cathode ray tube including an electron gun comprising a plurality of electrodes, an electron beam deflection device and a phosphor screen. This method includes placement of pole pieces of magnetic material in a deflection magnetic field produced by the electron beam deflection device and thereby locally modifies the deflection magnetic field in a path of an electron beam and corrects deflection defocusing of the electron beam corresponding to deflection of the electron beam in amount.