A display device (100) includes a display panel (2), and a backlight module (1). An optical sheet (11) in the backlight module (1) is arranged between a diffusing plate (12) and the display panel. The optical sheet (11) includes a first optical sheet component (11A) having a latching component (111) in the form of a tab defined by a cut in the first optical sheet component, and at least one second optical sheet component (11B) at least partially contacting the first optical sheet component (11A). The at least one second optical sheet component (11B) is clamped between the latching component (111) and a portion of the first optical sheet component (11A) other than that forming the latching component (111). This arrangement suppresses or prevents a wrinkling of the optical sheet components (11A, 11B) in the presence of a humid environment or thermal fluctuations which degrades the quality of the displayed image.