Patent ID: 8422130

Claim:
A portable magnifying instrument comprising: an optical system including an eyepiece lens system and an objective lens system, the optical system being configured to provide a continuously variable magnification view of a three-dimensional object; a controlled illumination system configured to illuminate the object, the illumination system including a plurality of light emitting diodes; a power supply connected to the illumination system and configured to supply power to the light emitting diodes; and a mounting configured to hold the light emitting diodes so that the angle between the light emitting diodes and the optical axis of the lens system is maintained and so that the light beam from the light emitting diodes can impinge on the object at the focus of the lens system; wherein the optical system is configured so that the magnification can be varied continuously by changing an effective tube length of the optical system using at least one of a threaded eyepiece, an eyepiece translated by a rack-pinion, or a guide in a slot; wherein the optical system is configured to provide continuously variable magnification in the range of 10× to 15× magnification and further configured to have a working distance from the objective lens system in the range of from 75 mm to 150 mm; wherein at least one of the eyepiece lens system or the objective lens system includes a combination of multiple lenses including doublets; and wherein the illumination system includes two 1.5 v light emitting diodes; the instrument further comprising: at least one of an ergonomic handle and a tripod mount coupled to the mounting; and a continuously variable dimmer switch to control the power provided from the power pack to the light emitting diodes.