Two-dimensional image projection system

• US 7,333,260 B2
• Filed: 08/09/2004
• Issued: 02/19/2008
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Stereo Display, Inc.
• Original Assignee: Stereo Display, Inc.
• Inventors: Seo, Cheong Soo, Cho, Gyoung Il, Kim, Tae Hyeon
• Primary Examiner(s): THOMPSON, TIMOTHY J
• Application Number:
  US10/914,474
• Publication Number:
  US 20060028709A1
• Time in Patent Office: 1,289 Days
• Field of Search: 359/291, 359/290, 359/295, 359/298, 359/223, 359/224, 359/625, 359/626, 359/318, 345/108, 347/239
• US Class Current: 359/291
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• 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: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129
• CPC Class Codes: H04N 9/3173 wherein the projection device is specially adapted for enhanced portability
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A two-dimensional image projection device using array of micromirror array lenses and a random scanning technique is invented. Using the random scanning technique, the light efficiency is nearly doubled than that of the prior art. The invention makes a brighter and less power consuming display device possible. Because each micromirror array lens of array of micromirror array lenses can scan whole image plane, a fast self diagnosis and correction technique can be introduced in displaying device. The Self diagnosis and correction technique makes display device to maintain image quality even a few tens percent of micromirrors do not work properly. Owing to the scanning characteristics of micromirror array lens, the image projection device can express the same number of pixels image with less number of micromirrors than the prior art. This also enables small sized two-dimensional image projector, which can be incorporated in portable electronic equipments.

Claims

1. A two-dimensional image projection device comprising an array of micromirror array lenses, wherein the micromirror array lenses comprise a plurality of micromirrors with at least one degree of freedom rotation, wherein the rotation of the micromirrors is controlled to change the focal length of the micromirror array lenses, wherein the array of micromirror array lenses scans light on a plane by the rotation of the micromirrors, the light being scanned by transversing the light focused from a micromirror array lens along the plane.

2. The image projection device of claim 1, wherein each micromirror array lens scans light along a plane independently from the other micromirror array lenses.

3. The image projection device of claim 1, wherein several micromirror array lenses scan the same positions in a plane simultaneously.

4. The image projection device of claim 1, wherein each of the micromirror array lenses scan the plane at different speeds.

5. The image projection device of claim 1, wherein the device scans the plane using a random scanning technique.

6. The image projection device of claim 1, wherein a gray scale is achieved by changing the scanning speed of the micromirrors.

7. The image projection device of claim 1, wherein a gray scale is achieved by varying the number of micromirrors of each micromirror array lenses.

8. The image projection device of claim 1, wherein a gray scale is achieved by changing the number of micromirror array lenses simultaneously focused on a point along the plane.

9. The image projection device of claim 1, wherein a gray scale is achieved by changing the scanning speed and size of the micromirror array lenses.

11. The image projection device of claim 1, wherein the device identifies defective micromirrors and re-calibrates the device by excluding the defective micromirrors and adjusting the combination of micromirror array lenses and respective speeds in which they scan the plane.

12. The image projection device of claim 1, further comprising:

a light source that generates collimated light, wherein the light is reflected by the array of micromirror array lenses and focused at a point in space;

a projection plane for displaying an image, wherein the light reflected by the array of micromirrors array lenses is focused onto projection plane;

an image sensor comprising a photo detector that detects light spots along the projection plane, the image sensor generating an data signal comprising image data;

an image processor in communication with the image sensor, wherein the image processor receives the data signal sent by the image sensor; and

a controller that generates and sends to each the micromirror array lenses an control signal comprising control data to adjust the configuration of the micromirror array lenses.

13. The image projection device of claim 12, wherein the focused light corresponds to a pixel of a displayed image.

14. The image projector of claim 1, wherein the projector uses automatic focusing signal processing.

15. The image projector of claim 1, wherein the projector is embodied within a mobile phone.

16. The image projector of claim 1, wherein the projector is embodied within a personal digital assistant.

17. The image projector of claim 1, wherein the projector is embodied within a camcorder.

18. The image projector of claim 1, further comprising:

a light source that produces collimated light, wherein the light is deflected by the array of micromirror array lenses and focused at a point in space;

a projection plane for displaying an image, wherein the light deflected by the array of micromirror array lenses is focused onto the projection and an image is displayed;

an image sensor comprising a photo detector that detects scattered light from the image, the image sensor generating a data signal comprising image data;

an image processor in communication with the image sensor, wherein the image processor receives the data signal sent by the image sensor, analyzes the image data, and generates a status signal comprising image focusing status data; and

a random scanning processing unit in communication with the image processor, wherein the random scanning processing unit receives the status signal sent by the image processor, and generates a control signal that is sent to the array of micromirror array lenses to adjust the focusing of the micromirror array lenses.

22. The image projection device of claim 1, wherein each micromirror array lens can change its focal length independently from the other micromirror array lenses.

23. The image projection device of claim 1, wherein each micromirror array lens can change its optical axis independently from the other micromirror array lenses.

24. The image projection device of claim 1, wherein the number of micromirrors comprising one micromirror array lens independently varies from the number of micromirrors comprising the other micromirror array lenses.

10. The image projection device of clan 1, wherein each micromirror has three degrees-of-freedom motion.

19. A method of focusing light on a point along a plane;

comprising;

generating light from a light source;

providing an array of micromirror array lenses comprising a plurality of micromirrors which reflect and focus the light onto the plane, wherein the focused light corresponds to a pixel of a displayed image;

receiving an image signal comprising image data, wherein the image data is transmitted to a processing unit and the processing unit sends an optimized control signal to the array of micromirror array lenses to adjust the focus of each micromirror array lenses;

detecting light scattered from the displayed image to generate a data signal carrying image data;

analyzing the data signal to produce a status signal carrying image focusing status data; and

processing the image focusing status data to produce a control signal that is sent to the array of micromirror array lenses to adjust the focusing of each of the micromirror lenses in the array.

20. The method of claim 19, wherein the optimized control signal carries data to produce the most optimized set of micromirror array lens combinations.

21. A method of displaying an image on a plane, comprising:

generating light from a light source;

providing an array of micromirror array lenses comprising a plurality of micromirrors which reflect and focus the light onto the plane, wherein the focused light corresponds to a pixel of the displayed image;

receiving an image signal comprising image data, wherein the image data is transmitted to a processing unit and the processing unit sends a control signal to the array of micromirror array lenses to adjust the focus of each micromirror array lenses; and

focusing the light randomly at certain positions corresponding to the image data along the plane until the image is displayed.