Backlight module, display module, and display apparatus

A backlight module, comprising a back plate, a plastic frame disposed on one side of the back plate and connected with the back plate, a light source assembly located on an inner side of the plastic frame, and a reflective sheet, a light guide plate, and an optical membrane group sequentially stacked and located on the inner side of the plastic frame;

• wherein the light source assembly comprises a circuit board and a light source disposed on a first side surface of the circuit board, and the light source is located at a first side edge of the light guide plate;
• the light guide plate comprises a first surface facing the reflective sheet and a second surface facing away from the reflective sheet;
• a first rectangular annular step and a second rectangular annular step are provided on an end face of the plastic frame facing the back plate, a portion of the reflective sheet close to an outer edge of the reflective sheet is bonded to the first rectangular annular step through a first double-sided adhesive tape, and the reflective sheet is also bonded by the first double-sided adhesive tape to a portion of the first surface of the light guide plate close to a remaining side edge of the light guide plate except the first side edge;
• and
• a portion of the second surface of the light guide plate close to the outer edge of the reflective sheet is disposed toward the second rectangular annular step, and a portion of the second surface of the light guide plate close to the first side edge is fixed on the second rectangular annular step.