Backlight module having reflective index adjustment material, method for preparing the same, method for driving the same, and display device

A method for preparing a backlight module, comprising:

• preparing a plurality of light emitting units arranged on the substrate at intervals to form the backlight source in the backlight module;
• preparing a light guide structure in the backlight module, the light guide structure comprising a first medium layer and a second medium layer, wherein the first medium layer comprises a plurality of first medium structures corresponding to the plurality of light emitting units respectively;
• and the second medium layer comprises a plurality of second medium structures, the plurality of second medium structures and the plurality of first medium structures are arranged alternately, and a refractive index of each second medium structure is less than a refractive index of each first medium structure;
• and
• laminating the light guide structure on the light emitting surface of the plurality of light emitting units, wherein an orthogonal projection of each light emitting unit on the substrate is located within an orthogonal projection of a corresponding first medium structure on the substrate,
• wherein the backlight module further comprises an electromagnetic unit, and the preparing the light guide structure comprises:
• forming a mold for preparing the first medium structure;
• preparing a mixed material of a transparent magnetic material, a mesoporous silica and a transparent elastic carrier, injecting the mixed material into the mold to form the first medium structure, and separating the first medium structure from the mold;
• and
• filling the blue filter material into the space formed between adjacent first medium structures to form the second medium structure;
• and
• the method further comprises preparing an electromagnetic unit on the substrate, wherein the electromagnetic unit is configured to form a controllable magnetic field, and the controllable magnetic field is configured to control the refractive index of the first medium structure.

A method for driving a backlight module, comprising:

• emitting light by a light emitting unit in the backlight source in the backlight module;
• and
• allowing the light to be incident into the first medium structure in a light guide structure in the backlight module, and forming an incident angle on an interface between the first medium structure and the second medium structure in the light guide structure, wherein the incident angle is greater than a critical angle of total reflection between the first medium structure and the second medium structure, so that the light directly leaves the light guide structure from the first medium structure,
• wherein the first medium structure is made of a magnetic-induced refractive index adjustment material, the second medium structure is made of a blue light filter material, and the backlight module further comprises an electromagnetic unit, and the method further comprises:
• forming a controllable magnetic field by the electromagnetic unit, wherein the controllable magnetic field controls a refractive index of the first medium structure, when the refractive index of the first medium structure is controlled to decrease, the light emitted by the light emitting unit is incident into the first medium structure, and an incident angle is formed on an interface between the first medium structure and the second medium structure, the incident angle is less than a critical angle of total reflection between the first medium structure and the second medium structure, such that the light is incident into the second medium structure, and leaves the light guide structure after being filtered by the second medium structure.