Reflection type liquid crystal display

• US 6,801,279 B2
• Filed: 11/01/2001
• Issued: 10/05/2004
• Est. Priority Date: 11/11/2000
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Uh, Kee-Han, Kim, Jae-Hyun, Jang, Yong-Kyu, Choi, Bang-Sil
• Primary Examiner(s): Weiss, Howard
• Application Number:
  US09/985,031
• Publication Number:
  US 20020089628A1
• Time in Patent Office: 1,069 Days
• Field of Search: 349/113, 257/59, 257/72
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

Disclosed is a reflection type liquid crystal display (LCD) and a manufacturing method thereof. A first substrate on which a pixel array is formed is prepared. A second substrate is formed facing the first substrate. A liquid crystal layer is formed between the first and second substrates. A reflective electrode is formed on the first substrate. The reflective electrode includes a plurality of first regions and a plurality of second regions having a height difference relative to the first regions, in which a first total sum in length components of the second regions arranged along a direction perpendicular to a first direction is greater than a second total sum in length components of the second regions arranged along a direction perpendicular to a second direction such that the second regions have higher reflectivity in the first direction relative to the second direction. A reflective electrode of oriented micro lenses defined by the first grooves and the second grooves is provided to enhance a reflection efficiency. The contrast and image quality are improved remarkably. The micro lenses are suitable for electronic displays that need a high reflectivity towards a specific direction. Since the reflective electrodes may be formed by an improved exposure and development process, the manufacturing cost and time would be reduced.

Claims

1. A liquid crystal display apparatus comprising:

a first substrate on which a pixel array is formed;

a second substrate facing the first substrate;

a liquid crystal layer between the first substrate and the second substrate; and

a reflective electrode formed on the first substrate, said reflective electrode including a plurality of first grooves and a plurality of second grooves, the first grooves being extended in a first direction, such that the reflective electrode has higher reflectivity in a second direction that is substantially perpendicular relative to the first direction, and the second grooves connecting the first grooves that are adjacent to each other.

2. The liquid crystal display apparatus of claim 1, wherein a distance between the first grooves is irregular.

3. The liquid crystal display apparatus of claim 1, wherein the first grooves and the second grooves have a uniform width.

4. The liquid crystal display apparatus of claim 1, wherein the first direction is the horizontal direction of the unit pixel.

5. The liquid crystal display apparatus of claim 1, wherein the second grooves have at least one of an arc shape and a straight line shape.

6. The liquid crystal display apparatus of claim 5, wherein the second grooves formed along the second direction are formed so as not to be aligned with adjacent second grooves on a line along the second direction.

7. The liquid crystal display apparatus of claim 5, wherein number of the second grooves formed along the second direction ranges from about 0.5 to about 5 per single horizontal line of a unit pixel.

8. The liquid crystal display apparatus of claim 5, wherein the reflective electrode comprises a groove blocker formed at crossed portions of the first grooves and the second grooves.

9. The liquid crystal display apparatus of claim 8, wherein the groove filling means is a protrusion extending from the second region and the groove blocker is in at least one shape selected from a shape group consisting of a Tshape, a triangle shape, an inverse triangle shape and a circle shape.

10. The liquid crystal display apparatus of claim 1, wherein the first and second grooves have a width in a range of 2-5 μ

m.

11. The liquid crystal display apparatus of claim 1, wherein region surrounded by the first and second grooves has at least two shapes selected from the group consisting of an ellipse shape, a waxing crescent moon shape, a waning moon shape, a track shape, a halftrack shape and an extended concave lens shape.

12. The liquid crystal display apparatus of claim 11, wherein a distance between the neighboring first grooves, and a distance between the neighboring second grooves ranges from about 4 μ

m to about 20 μ

m.

13. The liquid crystal display apparatus of claim 1, wherein a region surrounded by the first and second grooves comprises a scattering recess formed at a center portion.

14. The liquid crystal display apparatus of claim 1, further comprising a thin film transistor serving as a switching element, the thin film transistor comprising a gate electrode, a gate insulating film, a semiconductor layer, an ohmic contact layer, a source electrode and a drain electrode which are subsequently formed on the first substrate.

15. The liquid crystal display apparatus of claim 1, further comprising a thin film transistor serving as a switching element, the thin film transistor comprising a gate electrode, a source region and a drain region formed below the gate electrode, a gate insulating film formed between the gate electrode and the source region and the drain region, an oxide layer formed on the gate electrode, a source electrode connected to the source region and a drain electrode connected to the drain region.

16. The liquid crystal display apparatus of claim 1, further comprising an organic insulating film formed between the first substrate and the reflective electrode such that the organic insulating film has a same surface structure as the reflective electrode.

17. An electronic display device, comprising:

an insulating substrate on which a pixel array is formed; and

a reflector electrically connected to the pixel array and including a plurality of first grooves extended in a first direction, such that the reflective electrode has higher reflectivity in a second direction that is substantially perpendicular relative to the first direction, a distance between the first grooves being irregular.

18. The electronic display device of claim 17, further comprising a thin film transistor serving as a switching element, the thin film transistor comprising a gate electrode, a gate insulating film, a semiconductor layer, an ohmic contact layer and a source and drain electrode, or comprising a gate electrode, a source region and a drain region formed below the gate electrode, a gate insulating film formed between the gate electrode and the source region and the drain region, an oxide layer formed on the gate electrode, a source electrode connected to the source region and a drain electrode connected to the drain region.

19. A liquid crystal display apparatus comprising:

a first substrate on which a pixel array is formed;

a second substrate facing the first substrate;

a liquid crystal layer formed between the first substrate and the second substrate;

a reflective electrode formed on the first substrate, said reflective electrode including a plurality of first grooves extended in a first direction, such that the reflective electrode has higher reflectivity in a second direction that is substantially perpendicular relative to the first direction; and

an organic insulating film arranged between the first substrate and the reflective electrode and having a same surface structure as in the reflective electrode, the surface structure of the organic insulating film extending to outside of a boundary of a unit pixel.

20. The liquid crystal display apparatus of claim 19, wherein a distance between the first grooves is irregular.

21. The liquid crystal display apparatus of claim 20, wherein reflective electrode further including a plurality of second grooves connecting the neighboring first grooves, the second grooves having an arc shape, and the second grooves formed along the second direction are formed so as not to meet with adjacent second grooves on a line along the second direction.

22. The liquid crystal display apparatus of claim 21, wherein number of the second grooves formed along the second direction ranges from 0.5 to 5 per single horizontal line of a unit pixel.

23. The liquid crystal display apparatus of claim 22, wherein the reflective electrode comprises a protrusion portion formed at crossed portions of the first grooves and the second grooves.

24. An electronic display, comprising:

an insulating substrate on which a pixel array is formed;

a reflector electrically connected to the pixel array, said reflective means including a plurality of first grooves extended in a first direction, such that the reflective electrode has higher reflectivity in a second direction that is substantially perpendicular relative to the first direction, and a plurality of second grooves connecting the neighboring first grooves; and

an organic insulating film arranged between the first substrate and the reflective electrode and having a same surface structure as in the reflective means, wherein the surface structure of the organic insulating film extends to the outside of a boundary of a unit pixel.

25. The electronic display of claim 24, wherein a distance between the first grooves is not irregular.

26. The electronic display of claim 24, wherein the second grooves formed along the second direction are formed so as not to meet with adjacent second grooves on a line along the second direction.