Microlens array film and display device including the same

1. A microlens array film comprising:

a first transparent electrode and a second transparent electrode facing each other, at least one of the first and second transparent electrodes including a flat portion;

a flexible polymer layer having a surface for forming lenses, the flexible polymer layer being placed between the first and the second transparent electrodes;

a first substrate being in contact with at least a bottom surface of the flexible polymer layer, each of the first and second transparent electrodes being in direct contact with the first substrate; and

a second substrate being flexible and in contact with at least a top surface of the flexible polymer layer, each of the first and second transparent electrodes being in direct contact with the second substrate,

wherein a distance between the first transparent electrode and the second transparent electrode is reduced by applying voltages of opposite signs to the first and second transparent electrodes, respectively,

wherein the surface for forming lenses changes as result of when the distance between the first transparent electrode and the second transparent electrode is reduced.

2. The microlens array film as set forth in claim 1 , wherein the first transparent electrode, the flexible polymer layer, and the second transparent electrode constitute a single unit operating part, and

wherein the microlens array film includes a plurality of unit operating parts placed to be spaced apart from each other between the first and second substrates.

3. The microlens array film as set forth in claim 2 , wherein at least one of the first and second transparent electrodes extends to cover at least one of a top surface of the first substrate and a bottom surface of the second substrate.

4. The microlens array film as set forth in claim 1 , wherein the first substrate is transparent and flexible.

5. The microlens array film as set forth in claim 1 , wherein the flexible polymer layer is made concave laterally when voltages of opposite signs are applied to the first and second transparent electrodes, respectively.

6. The microlens array film as set forth in claim 1 , wherein a width of the flexible polymer layer adjacent to the second substrate is made smaller than that of the flexible polymer layer adjacent to the first substrate when voltages of opposite signs are applied to the first and second transparent electrodes, respectively.

7. The microlens array film as set forth in claim 1 , further comprising:

a reflection layer covering the first transparent electrode or the second transparent electrode.

8. A display device comprising:

a microlens array film set forth in claim 1 , and

a light source unit adjacent to the microlens array film.

9. The display device as set forth in claim 8 , wherein the light source unit includes a light source element, an optical waveguide adjacent to the light source element, and a mirror placed at the optical waveguide.

10. The display device as set forth in claim 8 , further comprising:

a condensing lens unit spaced apart from the light source unit with the microlens array film interposed therebetween and adapted to condense light emitted through the microlens array film.

11. The display device as set forth in claim 8 , further comprising:

a reflection plate spaced apart from the light source unit with the microlens array film interposed therebetween.

12. The display device as set forth in claim 8 , further comprising:

a reflection layer placed to cover a top surface of the microlens array film.

13. The display device as set forth in claim 12 , wherein at least the microlens array film is flexible.