LIQUID CRYSTAL PANEL, LIQUID CRYSTAL DISPLAY DEVICE AND TERMINAL DEVICE

Abstract

To provide a liquid crystal panel capable of realizing excellent display performance using a circular polarizing plate therein, and a liquid crystal display device and a terminal device using the same, with respect to a semi-transmission type liquid crystal display device in a horizontal electric field mode (In-Plane Switching: IPS).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a structure of a liquid crystal display device according to a first embodiment of the present invention;

FIG. 2 is a perspective view showing a terminal device on which the liquid crystal display device according to embodiments of the present invention is mounted;

FIG. 3 is a view showing a frame format of an optical operation when no voltage is applied between a pixel electrode and a common electrode which are components of the embodiment illustrated in FIG. 1;

FIG. 4 is a view showing a frame format of an optical operation when a voltage is applied between the pixel electrode and the common electrode which are components of the embodiment illustrated in FIG. 1;

FIG. 5 is a cross-sectional view showing a structure of a liquid crystal display device according to a second embodiment of the present invention;

FIG. 6 is a cross-sectional view showing a structure of a liquid crystal display device according to a third embodiment of the present invention;

FIG. 7 is a cross-sectional view showing a structure of a liquid crystal display device according to a fourth embodiment of the present invention;

FIG. 8 is a cross-sectional view showing a structure of a liquid crystal display device according to a fifth embodiment of the present invention;

FIG. 9 is a cross-sectional view showing a structure of a liquid crystal display device according to a sixth embodiment of the present invention;

FIG. 10 is a cross-sectional view showing a structure of a liquid crystal display device according to a seventh embodiment of the present invention;

FIG. 11 is a cross-sectional view showing a structure of a liquid crystal display device according to an eighth embodiment of the present invention;

FIG. 12 is a cross-sectional view showing a structure of a liquid crystal display device according to a ninth embodiment of the present invention;

FIG. 13 is a cross-sectional view showing a structure of a liquid crystal display device according to a tenth embodiment of the present invention;

FIG. 14 is a cross-sectional view showing a structure of a liquid crystal display device according to an eleventh embodiment of the present invention;

FIG. 15 is a cross-sectional view showing a structure of a liquid crystal display device according to a twelfth embodiment of the present invention;

FIG. 16 is a cross-sectional view showing a structure of a liquid crystal display device according to a thirteenth embodiment of the present invention;

FIG. 17 is a graph showing operations of the liquid crystal display devices according to the embodiments, in which the horizontal axis takes the thickness of the liquid crystal layer and the vertical axis takes the transmittance at the time of black display;

FIG. 18 is a graph showing operation of the liquid crystal display device as a comparative example of the embodiments, in which the horizontal axis takes the thickness of the liquid crystal layer and the vertical axis takes the transmittance at the time of black display;

FIG. 19 is a cross-sectional view showing a structure of a liquid crystal display device according to a fourteenth embodiment of the present invention;

FIG. 20 is a cross-sectional view showing a structure of a liquid crystal display device according to a fifteenth embodiment of the present invention;

FIG. 21 shows the result of simulating the liquid crystal orientation, electric field distribution, and transmittance distribution in a case where (1) w/d<1 applies;

FIG. 22 is an enlarged view of the liquid crystal orientation on an electrode according to the simulation result shown in FIG. 21;

FIG. 23 is a graph obtained by measuring the voltage-transmittance characteristics in an area with a diameter of 1 μm at the center between the electrodes;

FIG. 24 is a graph obtained by measuring the voltage-transmittance characteristics in an area with a diameter of 1 μm at the center on the electrodes;

FIG. 25 shows the result of simulating the liquid crystal orientation, electric field distribution, and transmittance distribution in a case where (2) w/d=1 applies;

FIG. 26 is an enlarged view of the liquid crystal orientation on an electrode according to the simulation result shown in FIG. 25;

FIG. 27 is a graph obtained by measuring the voltage-transmittance characteristics in an area with a diameter of 1 μm at the center between the electrodes;

FIG. 28 is a graph obtained by measuring the voltage-transmittance characteristics in an area with a diameter of 1 μm at the center on the electrodes;

FIG. 29 is a cross-sectional view showing the electric field structure and the liquid crystal orientation of the liquid crystal device when a voltage is being applied in a case where (3) (w+L)/d≦1 applies, which in particular shows a sectional view showing the relationship between the electric field structure and the liquid crystal orientation, the transmittance distribution through simulation;

FIG. 30 is a cross-sectional view showing the electric field structure and the liquid crystal orientation of the liquid crystal device when a voltage is being applied in a case where (4) (w+S)/d≦½ applies, which in particular shows a sectional view showing the relationship between the electric field structure and the liquid crystal orientation, the transmittance distribution through simulation;

FIG. 31 is a cross-sectional view showing a structure of a liquid crystal display device according to a sixteenth embodiment of the present invention;

FIG. 32 is a cross-sectional view for calculating the focal distance of a cylindrical lens that constitutes a lenticular lens according to the embodiment;

FIG. 33 is a cross-sectional view for calculating the focal distance of a cylindrical lens that constitutes a lenticular lens according to the embodiment;

FIG. 34 is a cross-sectional view for calculating the focal distance of a cylindrical lens that constitutes a lenticular lens according to the embodiment;

FIG. 35 is a cross-sectional view for calculating the focal distance of a cylindrical lens that constitutes a lenticular lens according to the embodiment;

FIG. 36 is a view showing a frame format of an optical configuration, arranged angles, and operations of a semi-transmission type liquid crystal panel in a horizontal electric field mode used for a liquid crystal display device described in Patent Document 1;

FIG. 37 is a cross-sectional view showing a semi-transmission type liquid crystal panel in a horizontal electric field mode used for a liquid crystal display device described in Patent Document 2;

FIG. 38 is a cross-sectional view showing a semi-transmission type liquid crystal panel in a horizontal electric field mode used for a liquid crystal display device described in Non-Patent Document 1;

FIG. 39 is a cross-sectional view showing a semi-transmission type liquid crystal panel in a vertical alignment mode used for a liquid crystal display device described in Non-Patent Document 2;

FIG. 40 is a view showing a frame format of a structure of a broadband quarter-wavelength plate used for a circular polarizing plate described in Non-Patent Document 3.

Claims

1. A liquid crystal panel comprising a backside substrate, a viewer-side substrate, and a liquid crystal layer in between those two substrates, where a pixel area is configured with a reflective display area in which a light from a viewer-side is reflected, and a transmissive display area in which a light from a backside is transmitted, and where a liquid crystal layer at least in a transmissive display area is driven by a horizontal electric field with an applied voltage parallel to a substrate surface, wherein the liquid crystal layer has a refractive index anisotropy in a display surface thereof,

2. The liquid crystal panel, as claimed in claim 1, wherein the compensator is a compensation plate, and the compensation plates are disposed individually between the respective substrates and the circular polarizing plates, those two compensation plates reduce a refractive index anisotropy of the liquid crystal layer in the transmissive display area, and one of those two compensation plates reduces a refractive index anisotropy of the liquid crystal layer in the reflective display area.

3. The liquid crystal display panel, as claimed in claim 2, wherein thickness of the liquid crystal layer is different between the reflective display area and the transmissive display area.

4. The liquid crystal panel, as claimed in claim 2, wherein the two compensation plates have equivalent characteristics.

5. The liquid crystal panel, as claimed in claim 1, wherein the compensator is a compensation plate, and the compensation plate is disposed in either intervals of the respective substrates and the circular polarizing plates, and the one compensation plate reduces a refractive index anisotropy of the liquid crystal layer in the reflective display area and a refractive index anisotropy of the liquid crystal layer in the transmissive display area.

6. The liquid crystal panel, as claimed in claim 5, wherein the compensation plate is set in a value with which the refractive index anisotropy of the liquid crystal layer in the transmissive display area is counteracted so that the liquid crystal layer has isotropy.

7. The liquid crystal panel, as claimed in claim 5, wherein thickness of the liquid crystal layer is even between the reflective display area and the transmissive display area.

8. The liquid crystal panel, as claimed in claim 1, wherein intensity of an electric field for driving the liquid crystal layer is weaker in the reflective display area than in the transmissive display area.

9. The liquid crystal panel, as claimed in claim 1, wherein an interval between electrodes generating a horizontal electric field in the reflective display area is wider than an interval of electrodes generating a horizontal electric field in the transmissive display area.

10. The liquid crystal panel, as claimed in claim 1, wherein the liquid crystal layer is parallel-aligned, and the compensator is a compensation plate, and the compensation plate uses a negative A plate of retardation film therefor, in which a direction of an extraordinary refractive index of the negative A plate is set in a direction in which refractive index anisotropy of the liquid crystal layer under no voltage application is maximum.

11. The liquid crystal panel, as claimed in claim 1, wherein the liquid crystal layer is parallel-aligned, and the compensator is a compensation plate, and the compensation plate uses a biaxial retardation film therfor, and between an A axis and a B axis of the biaxial retardation film, the axis having a smaller refractive index anisotropy is set in a direction in which refractive index anisotropy of the liquid crystal layer under no voltage application is maximum.

12. The liquid crystal panel, as claimed in claim 1, wherein the liquid crystal layer is twist-aligned, the compensator is a compensation plate, and the compensation plate uses a twisted-nematic retardation plate therefor.

13. The liquid crystal panel, as claimed in claim 12, wherein an orientation direction of liquid crystal molecules near the viewer-side substrate and an orientation direction of liquid crystal molecules near the backside substrate in the liquid crystal layer are arranged in line symmetry centering a perpendicular line to an electric field direction in the display surface.

14. The liquid crystal panel, as claimed in claim 1, wherein the compensator is a compensation layer, and the compensation layer is arranged at least in either one of areas between the liquid crystal layer and each of the substrates.

15. The liquid crystal panel, as claimed in claim 1, wherein the compensator is a polymer network compensation layer, and the polymer network compensation layer is arranged between the substrates.

16. The liquid crystal panel, as claimed in claim 1, wherein: electrodes for generating a horizontal electric field are a parallel electrode pair; a width of the electrodes is smaller than a thickness of the liquid crystal layer; orientation of liquid crystal molecules between the electrodes is changed by the electric field generated by the parallel electrode pair; orientation of liquid crystal molecules on the electrodes is changed like the liquid crystal molecules between the electrodes by conforming to the change in the orientation; and director direction of the liquid crystal molecules on the electrodes is a direction different from a direction of the electric field on the electrodes.

17. The liquid crystal panel, as claimed in claim 1, comprising a pixel magnifying device for optically magnifying the pixel.

18. A liquid crystal display device comprising the liquid crystal panel as claimed in claim 1, for a display unit.

19. A terminal device comprising the liquid crystal display device as claimed in claim 18.

20. The terminal device, as claimed in claim 19, is a portable telephone, a personal digital assistant, a game machine, a digital camera, a camcorder, a videoplayer, a laptop computer, a cash dispenser, or a vending machine.