Direct-view MEMS display devices and methods for generating images thereon

• US 9,135,868 B2
• Filed: 08/29/2012
• Issued: 09/15/2015
• Est. Priority Date: 02/23/2005
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Hagood, Nesbitt W. IV, Gandhi, Jignesh, McAllister, Abraham, Malzbender, Rainer M., Lewis, Stephen R.
• Primary Examiner(s): Bukowski, Kenneth
• Application Number:
  US13/597,943
• Publication Number:
  US 20120320111A1
• Time in Patent Office: 1,112 Days
• Field of Search: 345105-111
• US Class Current: 1/1
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory

Abstract

A direct-view display includes an array of MEMS light modulators and a control matrix formed on a transparent substrate, where each light modulator can be driven into at least two states, and a controller for controlling the states of each light modulator in the array. The control matrix transmits data and actuation voltages to the array. The controller includes an input, a processor, a memory, and an output. The input receives image data encoding an image frame for display. The processor derives a plurality of sub-frame data sets from the image data, where each sub-frame data set indicates desired states of light modulators in multiple rows and multiple columns of the array. The memory stores the plurality of sub-frame data sets. The output outputs the plurality of sub-frame data sets according to an output sequence to drive light modulators into the states indicated in the sub-frame data sets.

Claims

1. An electromechanical device, comprising:

an array of light blocking elements, each respective light blocking element movable between at least two positions;

at least two light sources including a first light source generating light of a first color and a second light source generating light of a second different color; and

a controller for;

receiving image data encoding an image frame;

generating at least two sub-frames for each color component of a plurality of color components associated with the image frame, wherein each sub-frame corresponds to illumination and extinguishing of at least one light source,

moving each respective light blocking element between the at least two positions; and

controlling the light sources to generate light to pass towards the array of light blocking elements, wherein, for the image frame, the light of the first color is generated at a greater intensity and for a different length of time during an illumination period of a first sub-frame associated with a color component than during an illumination period of a second sub-frame associated with the color component.

2. The electromechanical device of claim 1, wherein a respective light blocking element corresponds to at least one aperture and blocks light from passing through the aperture while in at least one of the two positions.

3. The electromechanical device of claim 2, further comprising a transparent substrate, the apertures and the light blocking elements being formed on the transparent substrate.

4. The electromechanical device of claim 3, wherein the light blocking elements include electromechanical shutters that are movable transverse to the substrate to modulate light passing through the apertures.

5. The electromechanical device of claim 1, wherein during a sub-frame associated with a respective color component, the controller applies an electrical signal to drive the first light source at a greater intensity than the second light source.

6. The electromechanical device of claim 1, wherein the controller outputs a control signal to coordinate driving the array of light blocking elements and illuminating the at least two light sources to display a single sub-frame image.

7. The electromechanical device of claim 6, comprising a third light source, wherein the first light source corresponds to a red color, the second light source corresponds to a green color, and the third light source corresponds to a blue color.

18. The electromechanical device of claim 1, wherein the first and second colors include colors other than white.

8. An apparatus, comprising:

light generating means for generating light of at least a first color and a second color;

modulating means for modulating the light;

control means for;

receiving image data encoding an image frame;

generating at least two sub-frames for each color component of a plurality of color components associated with the image frame, each sub-frame corresponds to illumination and extinguishing of the light generating means;

moving the modulating means to one of at least two positions, based on the received image data; and

driving the light generating means to generate light to pass towards the modulating means, wherein for the image frame, the light of the first color is generated at a greater intensity and for a different length of time during an illumination period of a first sub-frame associated with a color component than during an illumination period of a second sub-frame associated with that color component.

9. The apparatus of claim 8, comprising a means for storing an output sequence parameter, the output sequence parameter including data corresponding to timing an intensity values.

10. The apparatus of claim 9, comprising applying electrical signals to drive the light generating means to generate light of at least the first and second color in accordance with the output sequence parameter data.

11. The apparatus of claim 8, wherein driving the light generating means includes driving the light generating means to generate light of at least the first color and the second color at the same time during an illumination period for a sub-frame image.

12. The apparatus of claim 8, wherein driving the light generating means to generate light occurs after moving the means for modulating light is complete.

19. The electromechanical device of claim 8, wherein the first and second colors include colors other than white.

13. An electromechanical device comprising:

a substrate;

an array of light blocking elements formed on the substrate, the respective light blocking elements having at least two positions;

at least two light sources that generate light of at least two colors to pass towards the array of light blocking elements; and

a controller for;

obtaining a plurality of sub-frame data sets from a memory for each color component of a plurality of color components, wherein the sub-frame data sets correspond to a portion of a time associated with display of an image frame;

controlling the position of the light blocking elements in the array according to the sub-frame data sets; and

illuminating at least one light source to display sub-frame images corresponding to sub-frame data sets associated with a respective color component, wherein for the image frame, light of a first color is generated at a greater intensity and for a different length of time during an illumination period of a first sub-frame image associated with the color component than during an illumination period of a second sub-frame associated with the color component.

14. The electromechanical device of claim 13, wherein the controller applies an electrical signal to drive, during an illumination period of a sub-frame associated with a color component, a first light source of one color at a greater intensity than the other light sources of different colors.

15. The electromechanical device of claim 13, wherein the at least two light sources comprise light sources of at least three different colors.

16. The electromechanical device of claim 13, wherein the light blocking elements comprise electromechanical shutters that move transverse to the substrate.

17. The electromechanical device of claim 13, wherein the substrate is transparent.

20. The electromechanical device of claim 13, wherein the at least two light sources generate colors other than white.