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US 7,944,428 B2Granted
Scanning backlight for flat-panel display
AssigneeMicrosoft Corporation
InventorAdrian Robert Leigh Travis
Life of this patent
Estimating the term…
Abstract
An illuminator for a flat-panel display comprises a tapered slab waveguide 1 co-extensive with the display, a light source 2-4 arranged to inject light into an edge of the waveguide so that it emerges over the face of the waveguide, and means for scanning the light injected into the wedge so that different areas of the panel are illuminated in turn. Preferably the light source is a set of rows of LEDs, each row injecting light at a different range of angles so that it emerges over different areas of the waveguide 1.
Claims10
An illuminator system for a-display, comprising:
- a slab waveguide disposed behind a back face of the display, wherein the slab waveguide is linearly tapered along a Y-axis of the back face of the display, and wherein the slab waveguide is substantially co-extensive with the back face of the display across the Y-axis and across an X-axis of the back face of the display, wherein the Y-axis and the X-axis are perpendicular to each other, and wherein the slab waveguide comprises a thick end and an opposing thin end that are each substantially parallel to the X-axis;
- a triangular input wedge that is a part of and that protrudes from the thick end of the slab waveguide;
- an input face of the triangular input wedge that is substantially co-extensive with the back face of the display along the X-axis;
- a plurality of N light arrays wherein each light array is configured to provide light that is substantially co-extensive with the back face of the display along the X-axis;
- a linear taper of the input face of the triangular input wedge that, in combination with an angle relative to the input wedge of incoming light from an Ith light array of the plurality of N light arrays, is configured to direct the incoming light from the Ith light array to emerge from a face of the slab waveguide over only an Ith portion of N portions of the back face of the display, wherein each of the N portions is substantially co-extensive with the back face of the display along the X-axis, and wherein each of the N portions are a different portion of the back face of the display than any other of the N portions;
- an illuminator system controller configured to synchronize with a controller of the display wherein the illuminator system controller turns off a previously turned-on light array of the plurality of N light arrays and turns on the Ith light array of the plurality of N light arrays in response to the controller of the display writing to a corresponding Ith portion of N corresponding portions of the display, and wherein the illuminator system does not utilize any display image data.
3 more elements
A method for illuminating a flat-panel display, comprising:
- injecting light from a plurality of N light arrays into an input linear wedge of a slab waveguide that is disposed behind a back face of the display, wherein the slab waveguide is linearly tapered along a Y-axis of the back face of the display, and wherein the slab waveguide is substantially co-extensive with the back face of the display across the Y-axis and across an X-axis of the back face of the display, wherein the Y-axis and the X-axis are perpendicular to each other, and wherein the slab waveguide comprises a thick end and an opposing thin end that are each substantially parallel to the X-axis, and wherein the input linear wedge is a part of and protrudes from the thick end of the slab wave guide, and wherein each light array of the plurality of N light arrays provides light that is substantially co-extensive with the back face of the display along the X-axis;
- and
- wherein the injecting light comprises turning off a previously turned-on light array of the plurality of N light arrays and turning on an Ith light array of the plurality of N light arrays in response to writing to a corresponding Ith portion of N portions of the display, wherein an input face of the input linear wedge is substantially co-extensive with the back face of the display along the second axis and substantially parallel to the X-axis, and wherein a linear taper of the input face of the input linear wedge, in combination with an angle relative to the input wedge of the Ith light array of the plurality of N light arrays, directs incoming light from the Ith light array to emerge from a face of the slab waveguide over only an Ith portion of N portions of the back face of the display, and wherein each of the N portions of the back face of the display is substantially co-extensive with the back face of the display along the X-axis, and wherein each of the N portions of the back face of the display are a different portion of the back face of the display than any other of the N portions of the back face of the display, and wherein the method for illuminating does not utilize any display image data.
Dependencies are inferred from the claim text.