Chart display device for visual acuity tests
US12064182B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 2021 |
| Grant date | Aug 20, 2024 |
| Priority date | — |
| Expiry date | Apr 14, 2043 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/005
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A chart display device for a visual acuity test includes a chart display optical unit that emits a chart image generated by a chart display optical system to a front, and is rotatably coupled to a frame of the chart display device via a rotation shaft; a position indicator light source that indicates the height of an eye to be examined and emits a position identification light; a position detection sensor that detects the position identification light emitted from the position indicator light source, and thus detects the height of the eye to be examined; and a rotation driving unit that rotates the chart display optical unit around the rotation shaft, and thereby tilts an emission direction of the chart image so that the chart image emitted from the chart display optical unit is emitted in the direction of the eye to be examined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.