A sudden, usually temporary increase in number or quantity: The baby boom created a bulge in school enrollment. v. bulged, bulgÂ·ing, bulgÂ·es. v.intr. To swell, protrude, or curve outward: a wall bulging after a flood; muscles bulging under a shirt. v.tr. To cause to bulge. [Middle English, pouch, from Old French bulge, bouge, from Latin bulga, bag, of Celtic origin; see bhelgh-in Indo-European roots.] bulgâ²iÂ·ness n. bulgâ²y adj. Synonyms: bulge, balloon, belly, jut, project, protrude These verbs mean to curve, spread, or extend outward past the normal or usual limit: a wallet bulging with money; a clown's pants that ballooned at the waist; a sail bellying in the wind; a boulder jutting from the hillside; a deck that projected from the house in back; eyes protruding from ...
One of the key components of the optical system of many compound microscopes is a condenser. A condenser is a lens that serves to concentrate light from the illumination source that is in turn focused through the object and magnified by the objective lens. It is a basic component of almost all compound light microscopes manufactured since the 19th Century.
Light diffracted by the specimen is presented as an inverted cone of half-angle (Î±), which represents the limits of light that can enter the objective. In order to increase the effective aperture and resolving power of the microscope, a condenser (Figure 1(b)) is added to generate a ray cone on the illumination side of the specimen. This enables the objective to gather light rays that are the result of larger diffraction angles, increasing the resolution of the microscope system. The sum of the aperture angles of the objective and the condenser is referred to as the working aperture.