Microlens assembly formed with curved incline and method for manufacturing the same, and light guiding plate, back light unit and display using the same

A method of manufacturing a microlens, comprising:

• a photosensitive material applying step of applying a photosensitive material to a surface of a substrate;
• a first exposure step of applying light to the surface of the substrate through a mask on which a polygonal pattern of which at least one side is replaced with a curve is formed;
• a second exposure step of applying light to the surface of the substrate through the mask at an angle different from that of the first exposure step;
• and
• a developing step of developing the photosensitive material exposed in the first exposure step and the second exposure step.

A method of manufacturing a microlens having a curved incline formed therein, comprising:

• a step of applying a photosensitive material to a surface of a substrate;
• a first exposure step of applying light to the surface of the substrate through a first mask having a polygonal pattern;
• a second exposure step of applying light to the surface of the substrate through a second mask having a pattern, which has a polygonal shape of which at least one side is replaced with a curve and which has an area equal to or less than that of the pattern of the first mask, at an angle different from that in the first exposure step;
• and
• a developing step of developing the exposed photosensitive material exposed in the first exposure step and the second exposure step.

A method of manufacturing a microlens having a curved incline formed therein, comprising:

• a photosensitive material applying step of applying a photosensitive material to a mask substrate having a polygonal pattern, at least one side of which is replaced with a curve, formed thereon;
• a first exposure step of applying light to the surface of the mask substrate;
• a second exposure step of applying light to the surface of the mask substrate at an angle different from that in the first exposure step;
• and
• a developing step of developing the photosensitive material exposed in the first exposure step and the second exposure step.

A light guiding plate comprising:

• a substrate that is made of a light transmitting material to transmit light emitted from a light source;
• and
• a microlens that is formed to protrude from the surface of the substrate, that is made of a light transmitting material to reflect and refract the light emitted from the light source, and that has a polyhedral shape including a bottom face coming in contact with the surface of the substrate, a top face opposed to the bottom face, and a plurality of side faces formed between the bottom face and the top face,
• wherein at least one side face crossing the traveling direction of the light emitted from the light source among the plurality of side faces is a curved face inclined about the bottom face.

A back light unit comprising:

• a light source;
• a light guiding plate including a substrate that is made of a light transmitting material to transmit light emitted from a light source and a microlens that is formed to protrude from the surface of the substrate, that is made of a light transmitting material to reflect and refract the light emitted from the light source, and that has a polyhedral shape including a bottom face coming in contact with the surface of the substrate, a top face opposed to the bottom face, and a plurality of side faces formed between the bottom face and the top face, wherein at least one side face crossing the traveling direction of the light emitted from the light source among the plurality of side faces is a curved face inclined about the bottom face;
• and
• a reflecting plate that is disposed on one surface of the light guiding plate and that reflects the light emitted from the light source.

A back light unit comprising:

• a light source;
• a light guiding plate including a substrate that is made of a light transmitting material to transmit light emitted from a light source and that has a micro groove of a polyhedral shape having a bottom face and a plurality of side faces, wherein at least one face crossing the traveling direction of the light emitted from the light source among the plurality of side faces of the micro groove is a curved face inclined about the bottom face;
• and
• a reflecting plate that is disposed on one surface of the light guiding plate and that reflects the light emitted from the light source.

A display device comprising:

• a light source;
• a light guiding, plate including a substrate that is made of a light transmitting material to transmit light emitted from a light source and a microlens that is formed to protrude from the surface of the substrate, that is made of a light transmitting material to reflect and refract the light emitted from the light source, and that has a polyhedral shape including a bottom face coming in contact with the surface of the substrate, a top face opposed to the bottom face, and a plurality of side faces formed between the bottom face and the top face, wherein at least one side face crossing the traveling direction of the light emitted from the light source among the plurality of side faces is a curved face inclined about the bottom face;
• a reflecting plate that is disposed on one surface of the light guiding plate so as to reflect the light;
• and
• a variable mask that is disposed on the other surface of the light guiding plate and that displays an image by blocking or transmitting the light reflected and refracted by the light guiding plate.

A display device comprising:

• a light source;
• a light guiding plate including a plate-like base layer that is made of a light transmitting material to transmit light emitted from a light source and a micro groove that includes a reflecting/refracting layer formed monolithically on the base layer and made of a light transmitting material to reflect and refract the light emitted from the light source, wherein the reflecting/refracting layer is a polyhedral groove including a bottom face opposed to the surface of the base layer and a plurality of side faces and at least one side face crossing the traveling direction of the light emitted from the light source among the plurality of side faces is a curved face inclined about the bottom face;
• a reflecting plate that is disposed on one surface of the light guiding plate so as to reflect light;
• and
• a variable mask that is disposed on the other surface of the light guiding plate and that displays an image by blocking or transmitting the light reflected and refracted by the light guiding plate.