Method and apparatus for automatically correcting image misalignment arising in a rear-projection LCD television display

• US 7,460,185 B2
• Filed: 08/17/2004
• Issued: 12/02/2008
• Est. Priority Date: 08/17/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Saletta, David
• Primary Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US10/919,741
• Publication Number:
  US 20060038927A1
• Time in Patent Office: 1,568 Days
• Field of Search: 348745-747, 348/806, 348/189, 348/190
• US Class Current: 348/745
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A method and apparatus for projecting an image is provided. The apparatus includes a projector operable to receive a signal representative of an image and to generate light representative of the image. A lens assembly is provided for receiving from the projector the generated light representative of the image and projecting the generated light. The generated light is projected onto a display screen so that the image is visible to a viewer. An image alignment arrangement adjusts a relative position of the image on the display screen. The image alignment arrangement, which is operable to project a test image from the projector onto the display screen, includes at least one sensor located on the display screen for detecting the test image and generating an alignment signal representative of an amount of misalignment of the test image on the display screen. The image alignment arrangement also includes a mechanical actuator for adjusting a relative position of the projector in response to the alignment signal so that the test image is properly aligned on the display screen.

Claims

1. An apparatus for projecting an image, comprising:

a projector operable to receive a signal representative of an image and to generate light representative of the image;

a lens assembly for receiving from the projector the generated light representative of the image and projecting said generated light;

a display screen onto which the generated light is projected so that the image is visible to a viewer;

an image alignment arrangement for adjusting a relative position of the image on the display screen, said image alignment arrangement being operable to project a test image from the projector onto the display screen and including;

at least one sensor located on the display screen for detecting the test image and generating an alignment signal representative of an amount of misalignment of the test image on the display screen; and

a mechanical actuator for adjusting a relative position of the projector in response to said alignment signal so that the test image is properly aligned on the display screen.

2. The apparatus of claim 1 further comprising at least one mirror receiving the generated light from the lens assembly and reflecting it to the display screen.

3. The apparatus of claim 1 wherein said display screen includes an overscan area in which said at least one sensor is located.

4. The apparatus of claim 1 wherein said test image comprises at least two lines perpendicular to one another.

5. The apparatus of claim 1 wherein said test image comprises a grid defined by a first series of lines that are perpendicular to a second series of lines.

6. The apparatus of claim 5 further comprising at least a first pair of sensors detecting a deviation by one of the at least two lines from a first prescribed orientation and at least a second pair of sensors detecting a deviation by the other of the at least two lines from a second prescribed orientation.

7. The apparatus of claim 6 wherein said display screen includes an overscan area in which said first and second pairs of sensors are located.

8. The apparatus of claim 1 wherein said projector employs an LCD panel as an optical switching element.

9. The apparatus of claim 1 wherein said mechanical actuator is operable to adjust the relative position of the projector in a single dimension.

10. The apparatus of claim 1 wherein said mechanical actuator is operable to adjust the relative position of the projector in at least a single dimension.

11. The apparatus of claim 10 wherein said mechanical actuator is operable to adjust the relative position of the projector in three dimensions.

12. The apparatus of claim 11 wherein said mechanical actuator is further operable to rotationally adjust the relative position of the projector.

13. A method for adjusting a relative position of an image on a screen of a display device, said method comprising the steps of:

projecting a test image from a projector onto the screen;

detecting a portion of the test image on the screen;

generating, in response to the detected portion of the lest image, an alignment signal representative of an amount of misalignment of the test image on the display screen; and

adjusting a relative position of the projector in response to said alignment signal so that the test image is properly aligned on the screen,

wherein the relative position of projector is adjusted by rotation of the projector.

14. The method of claim 13 further comprising the step of reflecting the test image received from the projector onto the screen.

15. The method of claim 13 wherein the detecting step is performed in an overscan area of the screen.

16. The method of claim 13 wherein said test image comprises at least two lines perpendicular to one another.

17. The method of claim 13 wherein said test image comprises a grid defined by a first series of lines that are perpendicular to a second series of lines.

18. The method of claim 17 wherein the detecting step is performed by at least a first pair of sensors detecting a deviation by one of the at least two lines from a first prescribed orientation and at least a second pair of sensors detecting a deviation by the other of the at least two lines from a second prescribed orientation.

19. The method of claim 18 wherein said screen includes an overscan area in said first and second pairs of sensors are located.

20. The method or claim 13 wherein said projector employs an LCD panel as an optical switching element.

21. The method of claim 13 wherein the relative position of the projector is adjusted in at least one dimension.

22. The method of claim 21 wherein the relative position of the projector is adjusted in three dimensions.

23. A rear-projection television, comprising:

a projector operable to receive a signal representative of an image and to generate light representative of the image;

a lens assembly for receiving from the projector the generated light representative of the image and projecting said generated light;

at least one mirror receiving the generated light from the lens assembly and reflecting it to the display screen;

a display screen onto which the generated light is projected so that the image is visible to a viewer,

an image alignment arrangement for adjusting a relative position of the image on the display screen, said image alignment arrangement being operable to project a test image from the projector onto the display screen and including;

at least one sensor located on the display screen for detecting the test image and generating an alignment signal representative of an amount of misalignment of the test image on the display screen; and

a mechanical actuator for adjusting, in response to said alignment signal, a relative position of at least one component selected from the group consisting of the projector, the lens assembly, and said at least one mirror so that the test image is properly aligned on the display screen.

24. The rear-projection television of claim 23 wherein said display screen includes an overscan area in which said at least one sensor is located.

25. The rear-projection television of claim 23 wherein said test image comprises at least two lines perpendicular to one another.

26. The rear-projection television of claim 23 wherein said test image comprises a grid defined by a first series of lines that are perpendicular to a second series of lines.

27. The rear-projection television of claim 26 further comprising at least a first pair of sensors detecting a deviation by one of the at least two lines from a first prescribed orientation and at least a second pair of sensors detecting a deviation by the other of the at least two lines from a second prescribed orientation.

28. The rear-projection television of claim 27 wherein said display screen includes an overscan area in which said first and second pairs of sensors are located.

29. The rear-projection television of claim 23 wherein said projector employs an LCD panel as an optical switching element.

30. The rear-projection television of claim 23 wherein said mechanical actuator is operable to adjust the relative position of the projector in a single dimension.

31. The rear-projection television of claim 23 wherein said mechanical actuator is operable to adjust the relative position of the projector in at least a single dimension.

32. The rear-projection television of claim 31 wherein said mechanical actuator is operable to adjust the relative position of the projector in three dimensions.

33. The rear-projection television of claim 32 wherein said mechanical actuator is further operable to rotationally adjust the relative position of the projector.