LIQUID CRYSTAL DISPLAY AND MANUFACTURING METHOD THEREOF

• US 20120196054A1
• Filed: 01/27/2012
• Published: 08/02/2012
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Jun-Woo, BAE, Jong-Sung, KIM, Hoi-Lim, JEON, Baek-Kyun, KANG, Suk-Hoon, JUNG, Jin-Soo, CHO, Soo-Ryun, YEOM, Joo Seok, Shin, Gyo-Jic, AHN, Hyun Ku, KIM, Kyoung Tae, KIM, Eun Ju
• Granted Patent: US 9,052,549 B2
• Time in Patent Office: Days
• US Class Current: 428/1.26
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: C08G 73/00 Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00 polycarbodiimides prepared from isocyanates C08G18/025, C08G18/797
• CPC Class Codes: C08G 73/10 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/027 Polyimide
• CPC Class Codes: G02F 1/133397 for suppressing after-image or image-sticking
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/134354 the sub-pixels being capacitively coupled
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 2201/122 having a particular pattern
• CPC Class Codes: G02F 2203/30 Gray scale
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

A liquid crystal display including: a first substrate and a second substrate facing each other; an alignment layer disposed on one of the first substrate and the second substrate and including a vertical photo-alignment material which includes a first vertical functional group and a photo-reactive group, and a major alignment material which does not include the photo-reactive group; and a liquid crystal layer disposed between the first substrate and the second substrate, wherein a ratio of a molar concentration of the vertical photo-alignment material to the molar concentration of the major alignment material increases in a direction towards a surface of the alignment layer adjacent to the liquid crystal layer.

Claims

1. A liquid crystal display comprising:

a first substrate and a second substrate facing each other;

an alignment layer disposed on one of the first substrate and the second substrate, the alignment layer comprising

a vertical photo-alignment material which comprises a first vertical functional group and a photo-reactive group, and

a major alignment material which does not include the photo-reactive group; and

a liquid crystal layer disposed between the first substrate and the second substrate,

wherein a ratio of a molar concentration of the vertical photo-alignment material to a molar concentration of the major alignment material increases in a direction towards a surface of the alignment layer adjacent to the liquid crystal layer.

2. The liquid crystal display of claim 1, wherein

the vertical photo-alignment material comprises a photo-reactive diamine group and a vertical diamine group.

3. The liquid crystal display of claim 2, wherein

the photo-reactive diamine group comprises

a first diamine group, and

a first flexible group bonded to the first diamine group, wherein

the photo-reactive group is bonded to the first flexible group, and

the first vertical functional group is bonded to the photo-reactive group.

4. The liquid crystal display of claim 3, wherein

the vertical diamine group comprises

a second diamine group,

a second flexible group bonded to the second diamine group, and

a second vertical functional group bonded to the second flexible group.

5. The liquid crystal display of claim 4, wherein

the vertical photo-alignment material comprises the photo-reactive diamine group in an amount of about 40 mole percent to about 70 mole percent, based on the total moles of the vertical photo-alignment material, and the vertical diamine group in an amount of about 10 mole percent to about 40 mole percent, based on the total moles of the vertical photo-alignment material.

6. The liquid crystal display of claim 2, wherein

the vertical diamine group comprises

a second diamine group,

a second flexible group bonded to the second diamine group, and

a second vertical functional group bonded to the second flexible group.

7. The liquid crystal display of claim 2, wherein

the vertical photo-alignment material includes the photo-reactive diamine group in an amount of about 40 mole percent to about 70 mole percent, based on the total moles of the vertical photo-alignment material, and the vertical diamine group in an amount of about 10 mole percent to about 40 mole percent, based on the total moles of the vertical photo-alignment material.

8. The liquid crystal display of claim 2, wherein

the vertical photo-alignment material includes two or more types of the photo-reactive diamine groups.

9. The liquid crystal display of claim 2, wherein the vertical photo-alignment material further comprises

a normal diamine group which does not comprise the photo-reactive group or the vertical functional group.

10. The liquid crystal display of claim 7, wherein

the vertical photo-alignment material includes the normal diamine group in an amount of less than about 20 mole percent, based on the total moles of the vertical photo-alignment material.

11. The liquid crystal display of claim 10, wherein

the alignment layer includes

the photo-reactive diamine group in an amount of about 4 mole percent to about 28 mole percent, based on the total moles of the vertical photo-alignment material,

the vertical diamine group in an amount of about 1 mole percent to about 16 mole percent, based on the total moles of the vertical photo-alignment material, and

the normal diamine group in an amount of about 60 mole percent to about 92 mole percent, based on the total moles of the vertical photo-alignment material.

12. The liquid crystal display of claim 9, wherein

the alignment layer includes

the photo-reactive diamine group in an amount of about 4 mole percent to about 28 mole percent, based on the total moles of the vertical photo-alignment material,

the vertical diamine group at about 1 mole percent to about 16 mole percent, based on the total moles of the vertical photo-alignment material, and

the normal diamine group at about 60 mole percent to about 92 mole percent, based on the total moles of the vertical photo-alignment material.

13. The liquid crystal display of claim 1, wherein

the vertical photo-alignment material is a polyamic acid compound represented by Formula 22, or a polyimide compound represented by Formula 23:

14. The liquid crystal display of claim 13, wherein

the major alignment material is a polyamic acid compound represented by Formula 24, or a polyimide compound represented by Formula 25:

15. The liquid crystal display of claim 2, wherein

the major alignment material is a polyamic acid compound represented by Formula 24, or a polyimide compound represented by Formula 25:

16. The liquid crystal display of claim 1, wherein

a position of the first vertical functional group in the alignment layer is selected based on a ratio of the molar concentration of the vertical photo-alignment material to the molar concentration of the major alignment material.

17. The liquid crystal display of claim 16, wherein

the first vertical functional group is disposed a distance of about 5 percent to about 50 percent of a thickness of the alignment layer from a surface of the alignment layer adjacent to the liquid crystal layer.

18. The liquid crystal display of claim 1, wherein

a weight ratio of the vertical photo-alignment material and the major alignment material is about 10:

90 to about 40;

60.

19. The liquid crystal display of claim 18, wherein

the major alignment material includes a third vertical functional group in an amount of less than about 5 mole percent, based on the total moles of the major alignment material.

20. The liquid crystal display of claim 1, wherein

the vertical photo-alignment material includes an imide group in an amount of about 40 mole percent to about 70 mole percent, based on the total moles of the vertical photo-alignment material.

21. The liquid crystal display of claim 20, wherein

the major alignment material includes an imide group in an amount of about 50 mole percent to about 80 mole percent, based on the total moles of the major alignment material.