| 摘要 |
A variable light beam lighting device (1), useable in particular in a flashlight, presenting a casing (2) a light source (3), in particular a LED, a first and a second optical element (11, 12) for conveying the light emitted by the source into a beam extending about an axis (A), and an adjustment mechanism (13) for adjusting the distance between the optical elements (11, 12) along the axis (A) and varying the convergence of the beam about the axis; the optical elements (11, 12) present respective pluralities of lenses (31, 32) facing and opposed to one another, pairs of facing lenses (31, 32) having respective focuses aligned parallely to the axis (A) and arranged between the optical elements (11, 12); the lenses (31, 32) are integrally carried by respective optical elements (11, 12) and the adjustment mechanism (13) moves the optical elements with respect to each other along the axis (A) 20 to vary the relative position of the focuses of the pairs of facing lenses (31, 32). |
