Method of letting a sufficient quantity of light pass through each of apertures for entry of backlight

• US 20070013830A1
• Filed: 10/20/2005
• Published: 01/18/2007
• Est. Priority Date: 07/12/2005
• Status: Active Grant

• Current Assignee: Miyakawa Company Limited
• Original Assignee: Miyakawa Company Limited
• Inventors: Hayakawa, Takashi
• Granted Patent: US 7,542,107 B2
• Time in Patent Office: Days
• US Class Current: 349/95
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

A liquid crystal display (LCD) panel has apertures for entry of backlight. A micro-lens array comprises micro-lenses of a resin on a transparent base. The base and each of the micro-lenses have a surface energy difference falling in or constrained to a predetermined range. The shape of each of the micro-lenses is such that collimated light substantially orthogonally incident to each of the micro-lens is compressed into a tight beam to enter one of the apertures.

Claims

1. A micro-lens array for a liquid crystal display (LCD) panel having apertures for entry of backlight, the micro-lens array comprising:

a transparent base; and

micro-lenses of a resin on the base, the base and each of the micro-lenses having a surface energy difference falling in a predetermined range,

wherein the shape of each of the micro-lenses is such that collimated light substantially orthogonally incident to each of the micro-lens is compressed into a tight beam to enter one of the apertures.

2. The micro-lens array as claimed in claim 1, wherein the predetermined range is from 5 dyne/cm² to 20 dyne/cm².

3. The micro-lens array as claimed in claim 2, wherein the micro-lenses have a height in the z direction not greater than 10 microns and a width in the x and y directions not greater than 150 microns.

4. The micro-lens array as claimed in claim 2, wherein the base has first and second faces, the second face being substantially planar, the first face bearing the micro-lenses thereon, and wherein the shape of the micro-lenses and thickness of the base are such that collimated light substantially orthogonally incident to each of the micro-lenses is focused at a point distant from the second face of the base after having past through the one aperture.

5. The micro-lens array as claimed in claim 1, wherein the base is a polarizer film.

6. The micro-lens array as claimed in claim 1, wherein the base is an optical film.

7. The micro-lens array as claimed in claim 4, wherein the resin has an index of refraction of between 1.30 and 1.70.

8. A method of letting a sufficient quantity of light pass through each of apertures for entry of backlight to liquid crystal (LC) of a liquid crystal display (LCD) panel, the method comprising:

utilizing an inkjet head to deposit droplets of a liquid resin composition on a transparent base in alignment with the apertures;

constraining a surface energy difference between each of the droplet and the base to a predetermined range;

utilizing the surface energy difference to let the droplets grow into micro-lenses having a shape;

curing the micro-lenses to keep the shape such that collimated light substantially orthogonally incident to each of the micro-lenses is compressed into a tight beam to enter one of the apertures; and

exposing the base bearing the micro-lenses to backlight.

9. The method as claimed in claim 8, wherein the micro-lenses are arranged in rows and in columns such that the two of the micro-lenses which belong to the adjacent two of the columns belong to the adjacent two of the rows, respectively.

10. The method as claimed in claim 8,

wherein the apertures are arranged in rows and in columns;

wherein the inkjet head has a plurality of nozzles, the inkjet head having a home position and various inclined positions;

wherein the inkjet head is brought to a selected one of the various inclined positions in which the plurality of nozzles are in alignment with the at least some of the columns of the apertures, respectively.

11. The method as claimed in claim 8, wherein, when the base is moving in the x direction, the inkjet head discharges the liquid resin composition to arrange droplets on the base as arranged in rows and in columns such that the two of the droplets which belong to the adjacent two of the columns belong to the adjacent two of the rows, respectively.

12. The method as claimed in claim 8, wherein the predetermined range is from 5 dyne/cm² to 20 dyne/cm².

13. The method as claimed in claim 8, wherein the micro-lenses have a height in the z direction not greater than 10 microns and a width in the x and y directions not greater than 150 microns.

14. A system for letting a sufficient quantity of light pass through each of apertures for entry of backlight to liquid crystal (LC) of a liquid crystal display (LCD) panel, the system comprising:

an inkjet head configured to deposit droplets of a liquid resin composition on a transparent base in alignment with the apertures;

means for utilizing a surface energy difference constrained to a predetermined range to let the droplets grow into micro-lenses having a shape;

an unit configured to cure the micro-lenses to keep the shape such that collimated light substantially orthogonally incident to each of the micro-lenses is compressed into a tight beam to enter one of the apertures; and

means for exposing the base bearing the micro-lenses to backlight.

15. The system as claimed in claim 14, further comprising:

a turn table bearing a holder on which the LCD panel is placed, the apertures of the LCD panel being arranged in rows and in columns, an inkjet head module bearing the inkjet head;

wherein the turn table turns to rotate the LCD panel to an accurately oriented position in which the columns of the apertures extend in the x direction;

wherein the inkjet head has a home position and various inclined positions and the inkjet head module rotates to bring the inkjet head to a selected one of the various inclined positions in which the plurality of nozzles are in alignment with the at least some of the columns of the apertures, respectively.

16. The system as claimed in claim 14, wherein, when the base is moving in the x direction, the inkjet head discharges the liquid resin composition to arrange droplets on the base in rows and in columns such that the two of the droplets which belong to the adjacent two of the columns belong to the adjacent two of the rows, respectively.

17. The system as claimed in claim 14, wherein the predetermined range is from 5 dyne/cm² to 20 dyne/cm².

18. The system as claimed in claim 14, wherein the micro-lenses have a height in the z direction not greater than 10 microns and a width in the x and y directions not greater than 150 microns.

19. A micro-lens fabrication apparatus, comprising:

a liquid crystal display (LCD) panel having apertures for entry of backlight and a transparent base, the apertures being arranged in rows and in columns;

a holder on which the LCD panel is placed with the transparent base up;

a camera configured to pick up image of the apertures;

means for processing the picked up image of the apertures to determine a rotary angle through which the LCD panel should rotate to come to an accurately oriented position in which the columns of the apertures extend in the x direction and providing a control signal indicative of the determined rotary angle;

means for rotating the holder and the LCD panel through the determined rotary angle to the accurately oriented position in response to the control signal indicative of the determined rotary angle;

an inkjet head having a plurality of nozzles, the inkjet head having a home position and various inclined position;

a tank containing liquid resin composition;

means for bringing the inkjet head to a selected one of the various inclined position in which the plurality of nozzles are in alignment with at least some of the columns of the apertures, respectively;

means for moving the LCD panel in the x direction;

an inkjet controller configured to control discharge of the liquid resin composition via the nozzles to deposit droplets of the liquid resin composition on the transparent base, each in alignment with one of the apertures; and

means for curing the deposited droplets to make micro-lenses.