Jasper Display Corporation

Aurora Systems, Inc.

Elcos Microdisplay Technology, Inc.

Google Inc.

Other

Omnivision Technologies, Inc.

Edwin Lyle Hudson

David Charles McDonald

William Spencer Worley, Iii

Bo Li

Wing Hong Chow

John Gray Campbell

Robert Lo

W Spencer Worley, Iii

Kaushik Sheth

Jeffrey Tang Fung Li

James Michael Stover

David John Cowl

William Thomas Weatherford

Raymond Pinkham

Mike Stover

Shih-Ya Hong

Warren Robert Ong

W Spencer Iii Worley

A backplane operative to drive an array of emissive pixel elements forming a part of an automotive head lamp assembly is disclosed. Each pixel element comprises a memory cell operative to pulse width modulate a current mirror pixel drive circuit configured to drive an emissive element. The array of emissive pixel elements is divided into a plurality of interdigitated rows or columns serviced by independent row drivers or independent column drivers that may be driven by data selected to randomize the order in which the data on adjacent pixels of the same row are written, thereby effectively substantially reducing the visibility of any residual structures that may be present in the data driving the pixels of adjacent columns.

System and method for modulating an array of emissive elements

A plurality of pixel drive circuits form part of an array of emissive elements. The plurality of pixel drive circuits are disposed to form a plurality of rows and a plurality of columns. The plurality of pixel drive circuits are organized into sets of pixel drive circuits, and each set comprises at least one pixel drive circuit. A FET of a set of pixel drive circuits shares a common well with other FETs of similar function in the same set of pixel drive circuits positioned therein, such that the variance of the threshold voltages of those FETs is substantially reduced. Each of the pixel drive circuits comprises a circuit operative to deliver a current at a predetermined voltage to an emissive device and a memory circuit operative to receive modulation data and to use same to modulate the current output of the pixel drive circuit.

Backplane for an array of emissive elements

A backplane operative to drive an array of emissive pixel elements is disclosed. Each pixel element comprises a memory cell operative to modulate a plurality of current mirror drive elements configured to drive one emissive element, wherein a plurality of current mirror pixel drive elements may be individually enabled by external control signals. The width W of the reference current FET of a first selectable current mirror circuit will differ from the width W of the reference current FET of a second selectable current mirror circuit. The ratio of the width W of the current source FET to the width W of the reference current FET in a first selectable current mirror pixel drive element is equal to the ratio of the width W of the current source FET to the width W of the reference current FET in a second selectable current mirror pixel drive element.

A backplane operative to drive an array of emissive pixel elements is disclosed. Each pixel element comprises a memory cell operative to modulate a plurality of current mirror drive elements configured to drive one emissive element, wherein one current mirror pixel drive element is always operative to provide current if the memory cell is on and all other current mirror pixel drive elements may enabled subject to external control signals and the memory cell data state. The W/L ratio of each reference current FET is equal to the W/L ratio of all other reference current FETs. The W/L ratio of the current source FETs in each of the current mirror pixel drive elements is equal to the others. The present invention allows adjustment of the current density within the current source FET as well as the sensitivity of the current source FET to threshold voltage variation.

A backplane operative to drive an array of emissive pixel elements is disclosed. Each pixel element comprises a pixel circuit drive element and an emissive element, wherein the pixel circuit drive element comprises a memory cell, a current source element, and a modulation element. The present invention improves on an emissive display by providing a backplane and modulation system that enables fabrication of multi-color or monochrome LED display systems that operate efficiently and without objectionable image artifacts. One aspect of the present invention is to realize the backplane in a single crystal silicon process with a minimum number of metal layers while providing each color with a suitable operating voltage and drive current.

Backplane suitable to form part of an emissive pixel array and system and methods of modulating same

A method of pulse width modulating a spatial light modulator comprises determining a modulation sequence and applying the modulation sequence to the spatial light modulator in a time order method. The modulation sequence comprises a plurality of minor modulation segments. Each minor modulation segment comprises an always-on modulation segment in an always-on state. The plurality of minor modulation segments are temporally spaced such that the always-on modulation segments are spaced at predetermined intervals. Each minor modulation segment comprises at least one thermometer bit.

System and method for pulse-width modulating a phase-only spatial light modulator

A display device and modulation scheme for applying image data to an imager is disclosed. The display may use a modulation scheme wherein spacing of row write actions on the rows creates gray scale modulation, wherein one row spacing between sequential row write actions is at a first distance while another row spacing between sequential row write actions is at a distance greater than said first distance. The modulation scheme may create a series of write pointers that create a corresponding series of write planes. In some embodiments, modulation efficiency is increased allowing the use of lower frequency imaging circuits to achieve the same display image.

Modulation scheme for driving digital display systems

A method of organizing and ordering pulse width modulation image data is disclosed, so that it may be displayed on the pixels of a scrolling color display. The method includes a method of formatting received image data into a different form suitable for driving a pulse width modulated display and a method of distributing image data across a series of different image modulation segments to minimize flicker and gray scale errors. The method includes means for reducing lateral field effects between adjacent pixels in different data states.

System and method for pulse width modulating a scrolling color display

A display system which includes a display controller, a display unit, and a light source is disclosed. The display controller includes a processor unit, a memory device, a voltage source and, optionally, a light source control unit. The display unit includes an array of pixel cells and circuitry to receive logic and control voltages and data and operate the display, a transparent counter electrode, and a liquid crystal layer disposed between the two alignment layers. The pixel cell includes a storage element, a DC balance control switch, a pixel voltage override circuit, an inverter able to select between two voltages available to it, and a pixel electrode/mirror. In different modes of operation the pixel mirror voltage may be determined by the storage element or by the pixel voltage override circuit. The display system may display images in one period and reset to a fixed state in another period.

Pixel circuit and display system comprising same

A display device and modulation scheme for applying image data to an imager. The display may use a modulation scheme wherein spacing of row write actions on the rows creates gray scale modulation, wherein one row spacing between sequential row write actions is at a first distance while another row spacing between sequential row write actions is at a distance greater than said first distance. The modulation scheme may create a series of write pointers that create a corresponding series of write planes. In some embodiments, modulation efficiency is increased allowing the use of lower frequency imaging circuits to achieve the same display image.

A multiplexed pixel display includes a plurality of pixel electrodes, a plurality of storage elements, a first voltage supply terminal, a second voltage supply terminal, a common electrode, and a plurality of multiplexers each selectively coupling an associated one of the pixel electrodes with one of the first voltage supply terminal and the second voltage supply terminal responsive to a value of a data bit stored in an associated one of said storage elements. A controller is configured to sequentially write each bit of multi-bit data words to the storage elements, and assert, while each bit is stored in the storage elements, a first predetermined voltage on the first voltage supply terminal, a second predetermined voltage on the second voltage supply terminal, and a third predetermined voltage on the common electrode, for a time dependent on the significance of the stored bit. Various alternate controllers facilitate the use of additional driving schemes.

Display with multiplexed pixels and driving methods

Methods, apparatus, and systems for generating drive sequences for pulse width modulated displays are described. A pulse width modulated signal that includes a drive sequence of temporal segments that are activated and deactivated to produce a desired gray scale. The temporal segments can be non-binary, non-equally weighted. The drive sequence can also include at least two of the temporal segments are least significant bit segments and the other segments are higher order segments.

Growing community of inventors

Los Altos, CA, United States of America

Edwin Lyle Hudson