DISPLAY PANEL AND DISPLAY APPARATUS HAVING THE SAME

• US 20150042896A1
• Filed: 07/09/2014
• Published: 02/12/2015
• Est. Priority Date: 08/12/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Won-yong, CHOI, Hyeong-sik, HWANG, Ju-seong
• Granted Patent: US 9,977,298 B2
• Time in Patent Office: Days
• US Class Current: 348/790
• CPC Class Codes: G02F 1/133374 for displaying permanent signs or marks
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133567 on the back side
• CPC Class Codes: G02F 1/134327 Segmented, e.g. alpha numeric display
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G02F 1/1397 the twist being substantially higher than 90°, e.g. STN-, SBE-, OMI-LC cells
• CPC Class Codes: G02F 2201/44 Arrangements combining different electro-active layers, e.g. electrochromic, liquid crystal or electroluminescent layers
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: G02F 2203/64 Normally black display, i.e. the off state being black
• CPC Class Codes: G02F 2203/66 Normally white display, i.e. the off state being white
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen

Abstract

A display panel includes an upper plate including a first substrate, a first electrode layer formed on an inner surface of the first substrate, and an absorptive polarizing film formed on an outer surface of the first substrate and having a first polarization axis, a lower plate including a second substrate, a second electrode layer formed on an inner surface of the second substrate, and a reflective polarizing film formed on an outer surface of the second substrate and having a second polarization axis perpendicular or parallel to the first polarization axis, an LC layer filled between the upper plate and the lower plate, and an LC driving power supply connected between the first electrode layer and the second electrode layer and configured to selectively provide an LC driving voltage to the LC layer changing a polarization direction of incident light in the LC layer.

Claims

1. A display panel configured to be driven in any one mode of an external light transmission mode and an external light reflection mode, the display panel comprising:

an upper plate including a first substrate;

at least one first electrode layer formed on an inner surface of the first substrate;

a first polarizing film formed on an outer surface of the first substrate and having a first polarization axis;

a lower plate including a second substrate;

at least one second electrode layer formed on an inner surface of the second substrate;

a second polarizing film formed on an outer surface of the second substrate and having a second polarization axis, wherein the second polarization axis is either perpendicular to or parallel to the first polarization axis;

a liquid crystal (LC) layer between the upper plate and the lower plate; and

an LC driving power supply connected between the first electrode layer and the second electrode layer and configured to selectively provide an LC driving voltage to the LC layer,

wherein the LC layer has a first arrangement in which a polarization direction of incident light is changed by a preset angle in an entire region of the LC layer when the LC driving voltage is not applied, or a second arrangement in which the polarization direction of the incident light is maintained in at least a partial region of the LC layer, to which the LC driving voltage is applied, when the LC driving voltage is applied, and

wherein the first polarizing film includes an absorptive polarizing film, and the second polarizing film includes a reflective polarizing film.

2. The display panel as claimed in claim 1, wherein the preset angle is 90 degrees or 270 degrees.

3. The display panel as claimed in claim 1, wherein the first polarization axis is perpendicular to the second polarization axis, and the LC driving voltage is provided to the LC layer when the display panel is driven in the external light reflection mode.

4. The display panel as claimed in claim 1, wherein the first polarization axis is parallel to the second polarization axis, and the LC driving voltage is provided to the LC layer when the display panel is driven in the external light transmission mode.

5. The display panel as claimed in claim 1, wherein the upper plate includes only one first electrode layer, and the lower plate includes only one second electrode layer.

6. The display panel as claimed in claim 5, wherein exactly one of the first electrode layer and the second electrode layer partially covers the inner surface of the corresponding substrate on which it is formed, and the other of the first electrode layer and the second electrode layer covers substantially all the inner surface of the corresponding substrate on which it is formed.

7. The display panel as claimed in claim 5, wherein the first electrode layer and the second electrode layer have the same shape, and each of the first and second electrode layers partially covers the inner surface of the corresponding substrate on which it is formed.

8. The display panel as claimed in claim 5, wherein each of the first and second electrode layers covers substantially all the inner surface of the corresponding substrate on which it is formed.

13. The display panel as claimed in claim 1, wherein the upper plate includes a plurality of first electrode layers and the lower plate includes only one second electrode layer, wherein the plurality of first electrode layers are electrically isolated from each other by at least one insulating layer.

14. The display panel as claimed in claim 13, wherein any one layer of the plurality of first electrode layers is formed to cover substantially all the inner surface of the first substrate, and the other layers of the plurality of first electrode layers are formed to partially cover the inner surface of the first substrate, and the second electrode layer is formed to cover substantially all the inner surface of the second substrate.

15. The display panel as claimed in claim 14, wherein the one first electrode layer that covers substantially all the inner surface of the first substrate is a layer disposed closest to the first substrate among the plurality of first electrode layers.

16. The display panel as claimed in claim 14, wherein the other first electrode layers that partially cover the inner surface of the first substrate each have a respective shape, and wherein the shape of at least one of the other first electrode layers is different from the shape of at least one other of the other first electrode layers.

17. The display panel as claimed in claim 1, wherein the upper plate includes a plurality of first electrode layers electrically isolated from each other by at least one insulating layer, and the lower plate includes a plurality of second electrode layers electrically isolated from each other by at least one insulating layer.

18. The display panel as claimed in claim 17, wherein any one layer of the plurality of first electrode layers is formed to cover substantially all the inner surface of the first substrate, and the other layers of the plurality of first electrode layers are formed to partially cover the inner surface of the first substrate, and

any one layer of the plurality of second electrode layers is formed to cover substantially all the inner surface of the second substrate, and the other layers of the plurality of second electrode layers are formed to partially cover the inner surface of the second substrate.

9. The display panel as claimed in 1, wherein the upper plate includes only one first electrode layer and the lower plate includes a plurality of second electrode layers, wherein the plurality of second electrode layers are electrically isolated from each other by at least one insulating layer.

10. The display panel as claimed in claim 9, wherein the first electrode layer covers substantially all the inner surface of the first substrate, and one layer of the plurality of second electrode layers covers substantially all the inner surface of the second substrate, and the other layers of the plurality of second electrode layers partially cover the inner surface of the second substrate.

11. The display panel as claimed in claim 10, wherein the one second electrode layer that covers substantially all the inner surface of the second substrate is a layer disposed closest to the second substrate among the plurality of second electrode layers.

12. The display panel as claimed in claim 10, wherein the other second electrode layers that partially cover the inner surface of the second substrate each have a respective shape, and wherein the shape of at least one of the other second electrode layers is different from the shape of at least one other of the other second electrode layers.

19. A display apparatus, comprising:

a first display panel configured to display unspecified images; and

a second display panel disposed in front of the first display panel and configured to be driven in any one mode of an external light transmission mode and an external light reflection mode,

wherein the second display panel includes

an upper plate including a first substrate, at least one first electrode layer formed on an inner surface of the first substrate, and a first polarizing film formed on an outer surface of the first substrate and having a first polarization axis,

a lower plate including a second substrate, at least one second electrode layer formed on an inner surface of the second substrate, and a second polarizing film formed on an outer surface of the second substrate and having a second polarization axis, wherein the second polarization axis is either perpendicular or parallel to the first polarization axis,

a liquid crystal (LC) layer between the upper plate and the lower plate, and

an LC driving power supply connected between the first electrode layer and the second electrode layer and configured to selectively provide an LC driving voltage to the LC layer,

wherein the LC layer has a first arrangement in which a polarization direction of incident light is changed by a preset angle in an entire region of the LC layer when the LC driving voltage is not applied, or a second arrangement in which the polarization direction of the incident light is maintained in at least a partial region of the LC layer, to which the LC driving voltage is applied, when the LC driving voltage is applied, and

wherein the first polarizing film includes an absorptive polarizing film, and the second polarizing film includes a reflective polarizing film.

20. The display apparatus as claimed in claim 19, wherein the preset angle is 90 degrees or 270 degrees.

21. The display apparatus as claimed in claim 19, wherein the second display panel is driven in the external light transmission mode when the first display panel is turned on, and the second display panel is driven in the external light reflection mode when the first display panel is turned off.

22. The display apparatus as claimed in claim 19, wherein the display apparatus is a television.