Digital Light Processing Display Device

• US 20090058875A1
• Filed: 03/29/2007
• Published: 03/05/2009
• Est. Priority Date: 04/03/2006
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Bourbon, Pascal, Doyen, Didier, Borel, Thierry
• Granted Patent: US 9,253,458 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: H04N 2005/91392 using means for preventing making copies of projected video images
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 9/3123 using pulse width modulation
• CPC Class Codes: H04N 9/3197 using light modulating optical valves

Abstract

The invention relates to a display device using the DLP (Digital Light Processing) technology. This invention is in the field of digital cinema and content protection, where camcorder acquisition followed by immediate illegal distribution creates important revenue losses for content owners. According to the invention, the addressing of the display device is modified in order to introduce an anti-copy processing. The display device comprises modulation means for modulating the colour or brightness of video data of video pictures received at a first rate and for outputting at a second rate modulated video data, said second rate being a multiple of the first rate, subfield coding means for coding said modulated video data into subfield data, said subfield data being delivered at the second rate, and addressing means for addressing the array with said subfield data at a third rate. Advantageously, the third rate is not a multiple of the first rate.

Claims

1-10. -10. (canceled)

11. Method for displaying video pictures using an array of luminous elements, comprising the following steps:

generating at least two video sub-pictures from at least one video picture to display, so that the at least two video sub-pictures are different for some pixels representing a pattern,

using the at least two video sub-pictures for modulating the colour or brightness of said pattern,

the video data of pixels of video pictures being received at a first rate and the video data of pixels of video sub-pictures being outputted at a second rate, said second rate being a multiple of the first rate,

subfield coding said modulated video data of pixels of generated video sub-pictures into subfield data, said subfield data being delivered at the second rate, and

addressing the array with said subfield data at a third rate.

12. Displaying method according to claim 11, wherein said modulating of the colour or brightness of pixels of said pattern is performed around values to be displayed such that the mean colour or brightness of the pattern over the at least two video sub-pictures corresponds to that to be displayed in said at least one picture in the absence of a pattern.

13. Displaying method according to claim 12, wherein the modulation rate of said modulating is half the third rate.

14. Displaying method according to claim 12, wherein the third rate is selected such that said modulating is imperceptible by the human eye but creates artifacts when the displayed video pictures are captured by a video capturing device.

15. Displaying method according claim 11, wherein the third rate is not a multiple of the first rate.

16. Displaying method according to claim 11, wherein the third rate varies dynamically during the displaying of the video pictures.

17. Displaying method according to claim 11, wherein said luminous elements are micro-mirrors valves.

18. Display device comprising an array of luminous element for displaying video pictures wherein it further comprises:

means for generating at least two video sub-pictures from at least one video picture to display, so that the at least two video sub-pictures are different for some pixels representing a pattern and are then used for modulating the colour or brightness of said pattern, the video data of pixels of video pictures being received at a first rate and the video data of pixels of video sub-pictures being outputted at a second rate, said second rate being a multiple of the first rate,

subfield coding means for coding said modulated video data of pixels of generated video sub-pictures into subfield data, said subfield data being delivered at the second rate, and

addressing means for addressing the array with said subfield data at a third rate.

19. Display device according to claim 18, wherein the modulation means modulates the colour or brightness of pixels of said pattern around values to be displayed such that the mean colour or brightness of the pattern over the at least two video sub-pictures corresponds to that to be displayed in said at least one picture in the absence of a pattern.

20. Display device according to claim 19, wherein the rate of said modulation is half the third rate.

21. Display device according to claim 19, wherein the third rate is selected such that the modulation is imperceptible by the human eye but creates artifacts when the displayed video pictures are captured by a video capturing device.

22. Display device according to claim 18, wherein said luminous elements are micro-mirrors valves.