Transflective display

• US 20060028835A1
• Filed: 10/30/2003
• Published: 02/09/2006
• Est. Priority Date: 11/01/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Sandelius, Thomas
• Granted Patent: US 7,508,470 B2
• Time in Patent Office: Days
• US Class Current: 362/561
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133626 providing two modes of illumination, e.g. day-night

Abstract

A display unit for a portable electronic device includes a substantially transparent display layer having a front side for displaying information and a rear side, a color filter layer, a reflector, and a lighting system for illuminating the substantially transparent display from the rear side. The reflector is provided on a front side of the color filter layer facing a user, such that reflected light does not have to travel through the color filter layer. When the lighting system is switched on, the display unit operates in an emissive mode, and when the lighting system is switched off, the display unit operates in a reflective and/or transflective mode. The display unit thereby provides two modes of operation that combine peak performance of an emissive display with a transflective ability to be read without backlighting. In this way, a display is provided which has saturated colours and high luminance, and which is still possible to be read in strong sunlight.

Claims

1. A display unit for a portable electronic device, comprising:

a substantially transparent display layer having a front side for displaying information and a rear side;

a color filter layer;

a reflector; and

a lighting system for illuminating the substantially transparent display layer from the rear side, the lighting system configured to be switched on or off,

wherein, the display unit operates in an emissive mode when the lighting system is switched on, wherein the display unit operates in a reflective and/or transflective mode when the lighting system is switched off, and wherein the reflector is on a front side of the color filter layer facing a user, such that reflected light does not have to travel through the color filter layer.

2. A display unit according to claim 1, wherein the color filter layer is on the rear side of the substantially transparent display layer and the front side of the color filter layer faces the substantially transparent display layer, and wherein the front side of the color filter layer includes at least one reflector.

3. A display unit according to claim 2, wherein the at least one reflector covers less than 50% of a total area of the rear side of the color filter layer.

4. A display unit according to claim 2, wherein the at least one reflector covers less than 25% of a total area of the front side of the color filter layer.

5. A display unit according to claim 3, wherein the at least one reflector is provided in the a center of the front side of the color filter layer.

6. A display unit according to claim 3, wherein the at least one reflector is provided adjacent to an edge of the front side of the color filter layer.

7. A display unit according to claim 3, wherein the at least one reflector has a rectangular shape.

8. A display unit according to claim 3, wherein the at least one reflector has a circular shape.

11. A display unit according to claim 4, wherein the at least one reflector is provided in a center of the front side of the color filter layer.

12. A display unit according to claim 4, wherein the at least one reflector is provided adjacent to an edge of the front side of the color filter layer.

13. A display unit according to claim 4, wherein the at least one reflector has a rectangular shape.

14. A display unit according to claim 4, wherein the at least one reflector has a circular shape.

15. A display unit according to claim 5, wherein the at least one reflector has a rectangular shape.

16. A display unit according to claim 5, wherein the at least one reflector has a circular shape.

17. A display unit according to claim 6, wherein the at least one reflector has a rectangular shape.

18. A display unit according to claim 6, wherein the at least one reflector has a circular shape.

9. A portable electronic device comprising:

at least one display unit, comprising;

a substantially transparent display layer having a front side for displaying information and a rear side;

a color filter layer;

a reflector; and

a lighting system for illuminating the substantially transparent display layer from the rear side, the lighting system configured to be switched on or off, wherein the display unit operates in an emissive mode when the lighting system is switched on, wherein the display unit operates in a reflective and/or transflective mode when the lighting system is switched off, and wherein the reflector is on a front side of the color filter layer facing a user, such that reflected light does not have to travel through the color filter layer.

10. A portable electronic device according to claim 9, wherein the color filter layer is on the rear side of the substantially transparent display layer and the front side of the color filter layer faces the substantially transparent display layer, and wherein the front side of the color filter layer includes at least one reflector.