Ultrasonic microscope having an automatic focusing adjustment mechanism
US5553499A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1994 |
| Grant date | Sep 10, 1996 |
| Priority date | — |
| Expiry date | Sep 2, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K11/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Ultrasonic wave converged by an acoustic lens is made incident onto a sample and wave reflected from the sample is received and converted into received electric signal by a transducer. A part of this electric signal is picked up by a gate section and the signal thus picked up is applied to an attenuator where it is converted into a variable ratio of input to output. The strength of the signal thus gain-adjusted is compared with a threshold value by a comparator. Responsive to the comparison result thus obtained, the gain of the attenuator is adjusted to make the input/output ratio of the attenuator a desired value. A computer calculates the focus position of the acoustic lens from a gain curve of the attenuator changing when the acoustic lens is moved from a position, remote enough from its focus position, to the sample. Drivel signal responsive to the result thus calculated is applied to a Z-drive control section. As the result, the distance of the acoustic lens relative to the sample is adjusted to bring the acoustic lens to the focus position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.