a first frame;

a second frame facing the first frame and spaced apart from the first frame in a first direction;

a first supporter coupled with the first frame; and

a second supporter movably coupled with the first frame and disposed under the first supporter, the first supporter comprising:

a first support bar coupled with the first frame and extending in a second direction perpendicular to the first direction; and

a plurality of first branch portions protruding from the first support bar toward the second frame, the second supporter comprising:

a second support bar coupled with the first frame and extending in the second direction; and

a plurality of second branch portions protruding from the second support bar toward the second frame, wherein the plurality of second branch portions are configured to move in a direction parallel to the second direction;

wherein none of the plurality of first branch portions overlap any of the plurality of second branch portions when viewed in a plan view from a third direction perpendicular to the first direction and the second direction.