The ornamental design of a lightguide, substantially as shown and described.
FIG. 1 is a front perspective view of a light guide for modifying light distribution patterns of a light source(s) in accordance with the present invention.
FIG. 2 is a rear perspective view of the light guide in FIG. 1.
FIG. 3 is a top view thereof.
FIG. 4 is a bottom view thereof.
FIG. 5 is a left view thereof.
FIG. 6 is a right view thereof.
FIG. 7 is a front view thereof; and,
FIG. 8 is a back view thereof.
The broken lines, within the claimed design, in the interior portion of the light guide that depict protrusions and recesses, as well as on the edges of the light guide that depict recesses are for illustrative purpose only. None of the broken lines form a part of the claimed design.