| 摘要 |
PURPOSE:To shorten the measurement time and to improve the measurement precision by converting the P.D measured value of spectacles into an electric signal. CONSTITUTION:The spectacles A are pressed against a spectacle frame padding plate 1 and held on a spectacle holding member 2a, and then the optical center of a lens La is on the center of measurement light, i.e. on the center axis of a lens receiver 3 after the alignment of the lens La. The center axis of the lens receiver 3 is known previously, so the holding member 2a moves in parallel to the frame padding plate 1 in a perpendicular plane which contains said center axis and is perpendicular to the surface of the frame padding plate 1, so the distance from a specific position of the holding member 2a, i.e. position contacting the bridge center or the center position between the pads of the spectacles to the perpendicular plane corresponds to the P.D value of the lens La. The holding member 2a is coupled directly with a direct operated type potentiometer 5a, so position information on the holding member 2a is converted into an electric signal. Then, this is read directly on a display device corresponding to the electric signal, and neither mechanical readout operation nor recording operation is required. |
