FOCUSING VARIABLE-FOCAL-LENGTH ULTRASONIC TRANSDUCER

摘要

the invention u043eu0442u043du043eu0441u0438u0442u0441u00a0 to u043du0435u0440u0430u0437u0440u0443u0448u0430u044e future quality control materials and u0438u0437u0434u0435 - lee. purpose u0438u0437u043eu0431u0440u0435u0442u0435u043du0438u00a0 u00a0u0432u043bu00a0u0435u0442u0441u00a0 increase sensitivity. u0434u043bu00a0 in u043fu0440u0435u043eu0431u0440u0430u0437u043eu0432u0430u0442u0435u043bu0435 containing two lenses, the lens 2 and the lens 3 is u043fu043bu043eu0441u043au043eu0432u043eu0433u043du0443u0442u043eu0439, u043fu043bu043eu0441u043au043eu0432u044bu043fu0443u043au043bu0440u0439 with large radius of curvature, the radius of curvature is flat u0432u043eu0433u043du0443u0442u043eu0439 lenses 2.in addition, the acoustic impedance of the lens is u0430u043au0443u0441u0442u0438u0447u0435u0441u043au043eu043cu0443 u0438u043cu043fu0435u0434u0430u043du0441u0443 u0437u0432u0443u043au043eu043fu0440u043eu0432u043eu0434u00a0u0449u0435u0439 liquid 4. in this u0434u043eu0431u0438u0432u0430u044eu0442u0441u00a0 minimum acoustic aberrations was in the range of u043fu0435u0440u0435u043cu0435u0449u0435u043du0438u00a0 trick. 1 u0437.u043f.u0444 - lu, 2 u0438u043b.u2022: -; -; '.' '' - ''; 'u2022u2022' ^ '-,' '' ': - a' - '' - '' - '' - '..u2022 ^