DISPLAY WITH A REFLECTIVE LC PANEL, AND THE DISPLAY METHOD

• US 20120268438A1
• Filed: 04/24/2012
• Published: 10/25/2012
• Est. Priority Date: 04/25/2011
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Woo Cheol
• Application Number:
  US13/454,501
• Publication Number:
  US 20120268438A1
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G02F 1/13718 based on a change of the texture state of a cholesteric liquid crystal

Abstract

A display includes a reflective Liquid Crystal (LC) panel having an LC layer, an optical unit having a light source, and a transmission plate unit stacked on the reflective LC panel. The transmission plate unit includes a first transmission plate and a second transmission plate that have respective and different indexes of refraction. Light incident on a first side of the first transmission plate is totally internally-reflected by a boundary between the first transmission plate and the second transmission plate, and travels through the first transmission plate to the reflective LC panel. The LC layer of the reflective LC panel reflects the incident light of spectra corresponding to pixel signals in order to display a video.

Claims

1. A display comprising:

a reflective Liquid Crystal (LC) panel having an LC layer;

an optical unit having a light source; and

a transmission plate unit having a first transmission plate and a second transmission plate that have respective and different indexes of refraction and are stacked on the reflective LC panel,

wherein the transmission plate unit receives light from the optical unit via a first side of the first transmission plate unit, allows the light to be totally reflected between the first and second transmission plates and transmits the light so as to be incident on the reflective LC panel, and

wherein the reflective LC panel reflects the incident light of a spectrum corresponding to a pixel signal.

2. The display of claim 1, wherein the first transmission plate and the second transmission plate are coupled to each other, and

wherein the first transmission plate has a first index of refraction that is larger than a second index of refraction of the second transmission plate, so that light incident on the first side of the first transmission plate is totally internally-reflected by the second transmission plate so as to travel through the first transmission plate to the reflective LC panel.

3. The display of claim 2, wherein the transmission plate unit comprises an optical device disposed at a boundary between the optical unit and the second transmission plate in order to block light incident on the first side of the first transmission plate from being incident on the second transmission plate, and

wherein the optical device is at least one of a light screen tape, a light screen print material, and a light blocking tape.

4. The display of claim 2, wherein the reflective LC panel comprises:

sub-layers for reflecting light of a spectra of the light source;

partition walls for separating the sub-layers;

a first electrode and a second electrode located respectively at an upper side and a lower side of the sub-layers and the partition walls, for providing a voltage to the sub-layers; and

switching devices, connected to the first transmission plate, for driving the sub-layers,

wherein the first transmission plate is connected to a lower side of the first electrode, and

wherein the second transmission plate is connected to an upper side of the second electrode.

5. The display of claim 4, wherein the sub-layers comprise cholesteric LC for reflecting light of the spectra.

6. The display of claim 5, wherein the switching devices are transistors.

7. The display of claim 1, wherein the optical unit is operated according to a control of a user of the display.

8. A display comprising:

a reflective Liquid Crystal (LC) panel having an LC layer;

an optical unit having a light source;

a transmission plate unit having a first transmission plate and a second transmission plate that have different and respective indexes of refraction and which are stacked on the reflective LC panel;

a sensor for sensing an intensity of illumination of light near the reflective LC panel;

a controller for controlling the reflective LC panel to operate in at least one of a video display mode with a LC of the LC layer being in a planar state and a transparent display mode with the LC of the LC layer being in a homeotropic state and for turning on or off the optical unit according to the intensity of illumination of light near the reflective LC panel as sensed by the sensor; and

a driver Integrated Circuit (IC) for driving the reflective LC panel to be in the at least one of the video display mode and the transparent mode according to a control of the controller.

9. The display of claim 8, wherein, when the reflective LC panel is operated in the transparent mode, the controller controls the reflective LC panel so as to allow light to travel through the reflective LC panel, and

wherein, when the reflective LC panel is operated in the video display mode, the controller turns off the optical unit when the intensity of illumination of light near the reflective LC panel is greater than a reference value so as to allow the reflective LC panel to operate using peripheral light, and

wherein, when the reflective LC panel is operated in the video display mode, the controller turns on the optical unit when the intensity of illumination of light near the reflective LC panel is less than the reference value so as to allow the reflective LC panel to operate using light output from the light source of the optical unit.

10. The display of claim 9, wherein the first transmission plate and the second transmission plate are coupled to each other, and

wherein the index of refraction of the first transmission plate is greater than the index of refraction of the second transmission plate so that light incident on a first side of the first transmission plate is totally internally-reflected by the second transmission plate so as to travel through the first transmission plate to the reflective LC panel, and

wherein the transmission plate unit receives light from the optical unit via the first side of the first transmission plate unit, allows the received light to be totally reflected between the first transmission plate and the second transmission plate and transmits the light to be incident on the reflective LC panel, and

wherein the reflective LC panel reflects the incident light of a spectrum corresponding to a pixel signal.

11. The display of claim 10, wherein the transmission plate unit comprises an optical device disposed at a boundary between the optical unit and the second transmission plate in order to block light incident on the first side of the first transmission plate from being incident on the second transmission plate, and

wherein the optical device is at least one of a light screen tape, a light screen print material, and a light blocking tape.

12. The display of claim 10, wherein the reflective LC panel comprises:

sub-layers for reflecting light of a spectra of the light source;

partition walls for separating the sub-layers;

a first electrode and a second electrode located respectively at an upper side and a lower side of the sub-layers and the partition walls, for providing a voltage to the sub-layers; and

switching devices, connected to the first transmission plate, for driving the sub-layers,

wherein the first transmission plate is connected to a lower side of the first electrode, and

wherein the second transmission plate is connected to an upper side of the second electrode.

13. The display of claim 12, wherein the sub-layers comprise cholesteric LC for reflecting light of the spectra.

14. The display of claim 8, wherein the controller controls the optical unit to be on or off according to a user input.

15. A display method of a display that includes a reflective Liquid Crystal (LC) panel having an LC layer, an optical unit having a light source, a transmission plate unit for transmitting light of the optical unit, and a sensor for sensing an intensity of illumination of light near the reflective LC panel, the method comprising:

determining a display mode of the display to be one of a video display mode and a transparent mode; and

controlling the reflective LC panel to operate in a planar state if the display mode is the video display mode,

wherein the controlling of the reflective LC panel to operate in the planar state comprises;

sensing an intensity of illumination of light near the reflective panel using the sensor;

comparing the sensed intensity of illumination of light with a reference value;

turning off the optical unit to operate the reflective LC panel using a peripheral light when the sensed intensity of illumination of light is greater than the reference value; and

turning on the optical unit to operate the reflective LC panel using light output from the optical unit when the sensed intensity of illumination of light is less than the reference value.

16. The method of claim 15, further comprising:

controlling the reflective LC panel to operate in a homeotropic state if the display mode is in a the transparent display mode;

wherein the controlling of the reflective LC panel to operate in the homeotropic state comprises allowing light to travel through the reflective LC panel.

17. The method of claim 16, further comprising:

forming the transmission plate unit to have a first transmission plate and a second transmission plate that are coupled to each other,

wherein an index of refraction of the first transmission plate is larger than an index of refraction of the second transmission plate.

18. The method of claim 17, wherein the turning on of the optical unit to operate the reflective LC panel using the light output from the optical unit comprises providing light of the optical unit to a first side of the first transmission plate so that the incident light is totally internally-reflected by a boundary between the first transmission plate and the second transmission plate,

wherein the incident light travels through the first transmission plate to the reflective LC panel.

19. The method of claim 18, further comprising:

blocking light incident on the first side of the first transmission plate using an optical device disposed at the boundary between the optical unit and the second transmission plate,

wherein the optical device is at least one of a light screen tape, a light screen print material, and a light blocking tape.

20. The method of claim 15, further comprising:

determining whether a user inputs a command for turning the optical unit on or off; and

turning the optical unit on or off according the user input.