Ophthalmic examination apparatus
US4781453A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 12, 1987 |
| Grant date | Nov 1, 1988 |
| Priority date | — |
| Expiry date | May 12, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/145
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An ophthalmic examination apparatus directs a laser beam from a laser light source onto the fundus of an eye to scan the fundus two-dimensionally, picks up the light reflected back from the eye fundus and by means of a photoelectric transducer subjects the light to photoelectric conversion to obtain information about the eye fundus. A laser light source is provided that generates laser beams of a plurality of wavelengths, a first acousto-optical device selects one wavelength from among the plurality of laser beam wavelengths, a first optical deflector is used to scan a laser beam in one direction at a predetermined frequency, and a second optical deflector is used for scanning the laser beam in a direction at right-angles to the above direction at a frequency that is lower than the above frequency. The first optical deflector is constructed as the second acousto-optical device which is driven at an ultrasonic frequency, and by changing the range of variability of the ultrasonic frequency of the second acousto-optical device in accordance with the laser beam wavelength selected by the first acousto-optical device, the angle of deflection of the first optical deflector becomes the sa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.