Process for preparation of quadrangle unit

1. A method of cutting one or more kinds of quadrangular unit pieces having a relatively small size from a quadrangular base material to manufacture the quadrangular unit pieces, the method comprising:

(a) an inspection step of scanning a quadrangular base material in a longitudinal direction and in a lateral direction of the quadrangular base material to check positions of defects on the quadrangular base material;

(b) a calculation step of calculating a yield when imaginarily cutting the quadrangular base material using at least two virtual cutting frames, each virtual cutting frame having a plurality of cutters arranged in a fixed array forming a plurality of quadrangular unit pieces and each cutter having a fixed size, wherein the respective virtual cutting frames are different from each other in terms of cutter arrangement and cutter size;

(c) a selection step of selecting one of the virtual cutting frames in which the yield calculated at the calculation step (b) is within a range of above 30% of a maximum yield of quadrangular unit pieces in consideration of positions of defects, wherein the selected virtual cutting frame is set in a lateral or longitudinal direction from a first position to a second position when an increase in the yield is 20% or more of a previous calculated yield; and

(d) a manufacturing step of cutting the quadrangular base material using a cutting frame corresponding to the virtual cutting frame selected at the selection step (c) to manufacture quadrangular unit pieces,

wherein the method further comprises a virtual cutting step of cutting the quadrangular base material where the virtual cutting frames are imaginarily moved in the longitudinal direction or in the lateral direction of the quadrangular base material at predetermined intervals to obtain a position having the maximum yield, the imaginary cutting step being carried out prior to the selection step (c).

2. The method according to claim 1 , wherein the selection step (c) comprises selecting one of the virtual cutting frames providing the maximum yield.

3. The method according to claim 1 , wherein each of the cutters is a knife for cutting or a light source for cutting.

4. The method according to claim 3 , wherein the knife for cutting is a metal knife or a jet water knife, and the light source for cutting is a laser.

5. The method according to claim 1 , wherein the quadrangular unit pieces are cut from the quadrangular base material at a predetermined inclination angle (θ) to the quadrangular base material.

6. The method according to claim 5 , wherein the inclination angle (θ) is 45 degrees or 135 degrees based on a lower end of the quadrangular base material.

7. The method according to claim 5 , wherein the inclination angle (θ) is 0 degrees or 90 degrees based on a lower end of the quadrangular base material.

8. The method according to claim 1 , wherein the imaginary movement of the virtual cutting frames comprises spacing the virtual cutting frames apart from a cutting start end of the quadrangular base material by a predetermined distance.

9. The method according to claim 8 , further comprising imaginarily moving the virtual cutting frames from the cutting start end of the quadrangular base material to a position excluding a region in which defect distribution in the longitudinal direction of the quadrangular base material is relatively high in consideration of defect distribution on the quadrangular base material in the longitudinal direction thereof.

10. The method according to claim 1 , wherein the imaginary movement of the virtual cutting frames comprises spacing the virtual cutting frames apart from an upper end or a lower end of the quadrangular base material at predetermined intervals in regular sequence.

11. The method according to claim 10 , further comprising imaginarily moving the virtual cutting frames at movement intervals of 0.1 to 5% of a width of the quadrangular base material.

12. The method according to claim 10 , wherein the predetermined intervals are between 0.2 and 5 cm.

13. The method according to claim 1 , wherein the imaginarily cutting the quadrangular base material comprises:

moving the selected virtual cutting frame in the lateral direction of the quadrangular base material to a lateral position in which the yield is maximum for the lateral direction; and

moving the selected virtual cutting frame in the longitudinal direction of the quadrangular base material at the lateral position where the yield is maximum to obtain a longitudinal position where the yield is maximum for the longitudinal direction; and

cutting the quadrangular base material.

14. The method according to claim 13 , wherein the selected virtual cutting frame is moved three times or less in the lateral direction of the quadrangular base material.

15. The method according to claim 1 , wherein the quadrangular base material is a continuous material having a predetermined width and a relatively long length, and the cutters are arranged in a structure to repetitively cut the quadrangular base material by a predetermined length.

16. The method according to claim 1 , wherein the quadrangular base material is a film comprising a layer that absorbs or transmits only a specific-direction wave motion of light or an electromagnetic wave in the longitudinal direction thereof or in the lateral direction thereof.