Techniques for dual modulation display with light conversion

• US 10,657,906 B2
• Filed: 01/31/2018
• Issued: 05/19/2020
• Est. Priority Date: 03/08/2013
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Ninan, Ajit, Wan, Chun Chi
• Primary Examiner(s): Mistry, Ram A
• Application Number:
  US15/884,957
• Publication Number:
  US 20180174532A1
• Time in Patent Office: 839 Days
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules

Abstract

Techniques for driving a dual modulation display include generating backlight drive signals to drive individually-controllable illumination sources. The illumination sources emit first light onto a light conversion layer. The light conversion layer converts the first light into second light. The light conversion layer can include quantum dots or phosphor materials. Modulation drive signals are generated to determine transmission of the second light through individual subpixels of the display. These modulation drive signals can be adjusted based on one or more light field simulations. The light field simulations can include: (i) a color shift for a pixel based on a point spread function of the illumination sources; (ii) binning difference of individual illumination sources; (iii) temperature dependence of display components on performance; or (iv) combinations thereof.

Claims

1. A display system, comprising:

one or more illumination sources of a backlight configured to emit first light, the first light including at least one of UV spectral components or blue light spectral components;

one or more light conversion layers configured to be stimulated by the first light and to convert at least a portion of the first light and recycled light into second light, the one or more light conversion layers including quantum dots;

logic to compute color shifts as a function of respective distances that the first light emitted from the one or more illumination sources travels before being converted into the second light by the one or more conversion layers; and

a controller to adjust drive values for one or more light modulators based on the logic.

2. An apparatus comprising:

backlight control logic to control one or more illumination sources of a backlight configured to emit first light onto one or more light conversion layers, the one or more light conversion layers configured to be stimulated by the first light and to convert at least a portion of the first light into second light;

modulator control logic to control one or more light modulators, the one or more light modulators configured to modulate light transmitting through individual subpixels; and

light field simulation logic to perform at least one light field simulation for color shifts as a function of respective distances that the first light emitted from the one or more illumination sources travels before being converted into the second light by the one or more conversion layers, wherein the modulator control logic is configured to adjust drive values for the one or more light modulators based on the at least one light field simulation.

3. The apparatus of claim 2 further comprising logic to perform a light field simulation for non-uniformity of illumination sources of the backlight.