Test and alignment system for electronic display devices and test fixture for same

• US 5,969,756 A
• Filed: 06/26/1996
• Issued: 10/19/1999
• Est. Priority Date: 06/13/1994
• Status: Expired due to Fees

• Current Assignee: Photon Dynamics Canada Inc. (KLA Corporation)
• Original Assignee: Image Processing Systems, Inc. (Edenred SE)
• Inventors: Farrer, Paul, Buckley, Eric, Noonan, Andrew, Dawe, Wayne, Bukal, Branko, Nemeth, Karoly G.
• Primary Examiner(s): Lee, Michael
• Application Number:
  US08/670,694
• Time in Patent Office: 1,210 Days
• Field of Search: 348/180, 348/181, 348/184, 348/187, 348/188, 348/189, 348/190, 348/191
• US Class Current: 348/190
• CPC Class Codes: H01J 9/42 Measurement or testing during manufacture
• CPC Class Codes: H04N 17/04 for receivers

Abstract

A test and alignment system for an electronic display device comprises a test pattern generator to be connected to an electronic display device for causing images of video test patterns to be displayed by the electronic display device. A test fixture is positioned in front of the electronic display device to be tested and aligned. The test fixture includes a frame supporting a plurality of close-up optical sensors to sense and produce image signals corresponding to small areas of images displayed on the electronic display device and a plurality of wide-angle optical sensors behind the close-up optical sensors for sensing and producing image signals corresponding to large areas of images displayed on the electronic display device. A computer controls the test pattern generator and processes and analyses the image signals generated by the close-up and wide-angle optical sensors to perform a series of tests on the electronic display device. A display provides a visual indication of the results of the series of tests performed by the computer.

Claims

1. A test fixture for a test and alignment system for an electronic display device comprising:

a frame;

a plurality of close-up optical sensors mounted on said frame to sense and produce image signals corresponding to small areas of an image displayed on an electronic display device positioned adjacent said test fixture; and

a plurality of wide-angle optical sensors mounted on said frame behind said close-up optical sensors, said wide-angle optical sensors being calibrated using a calibration grid so as to have overlapping fields of view to sense and produce image signals corresponding to substantially the entire image displayed on said electronic display device, wherein said close-up optical sensors are positioned on said frame in front of said wide-angle optical sensors so as to be outside of the fields of view of said wide-angle optical sensors, at least some of said close-up optical sensors being moveably mounted on said frame.

2. A test fixture as defined in claim 1 wherein said close-up optical sensors include a plurality of rows of optical sensors, said optical sensors being angled in a direction towards said electronic display device.

3. A test fixture as defined in claim 2 further including at least one intermediate central row of optical sensors.

4. A test fixture as defined in claim 3 wherein said central row of optical sensors includes a vertically movable central optical sensor, said central optical sensor being positioned on said frame so that the field of view thereof includes the center of said image.

5. A test fixture as defined in claim 4 wherein said central optical sensor is pivotally mounted on said frame.

6. A test fixture as defined in claim 5 wherein said central optical sensor is pivotally mounted on a cantilever.

7. A test fixture as defined in claim 2 wherein said rows of optical sensors are supported on inclined rails mounted on said frame, said rails being vertically adjustable.

8. A test fixture as defined in claim 7 wherein the optical sensors in said rows are movable laterally along said respective inclined rails.

9. A test fixture as defined in claim 8 wherein the optical sensors in said rows include drive means to move said optical sensors laterally along said rails.

10. A test fixture as defined in claim 1 further including at least one wobulator mounted on said frame for creating an alternating magnetic field to bend electron beams within said electronic display device.

11. A test fixture as defined in claim 10 wherein said at least one wobulator includes at least one pair of laterally spaced, elongate electromagnets mounted on said frame outside of the fields of view of said close-up and wide-angle optical sensors and being energizable to generate a generally uniform alternating magnetic field, said alternating magnetic field encompassing generally the entire display screen of said electronic display device.

12. A test fixture as defined in claim 11 wherein said at least one wobulator includes a pair of vertically spaced, generally horizontal electromagnets and a pair of laterally spaced, generally vertical electromagnets, said pairs of electromagnets being energizable to generate alternating magnetic fields.

27. A test fixture as defined in claim 1 wherein at least one of said wide-angle and close-up optical sensors includes a CCD device and a fixed lens element, said CCD device being movable relative to said lens element to change the focus of said at least one optical sensor.

28. A test fixture as defined in claim 27 wherein said CCD device is mounted on a slide assembly responsive to a drive, said slide assembly being slidable along an axis parallel to an optical axis extending through said at least one optical sensor.

13. A test and alignment system for an electronic display device comprising:

a test pattern generator to be connected to an electronic display device for causing said electronic display device to generate images of video test patterns on said electronic display device;

a test fixture including a frame supporting a plurality of close-up optical sensors to sense and produce image signals corresponding to small areas of images displayed on said electronic display device and a plurality of wide-angle optical sensors to sense and produce image signals corresponding to larger areas of images displayed on said electronic display device, said close-up optical sensors being positioned on said frame so as to be outside of the fields of view of said wide-angle optical sensors, at least some of said close-up optical sensors being moveable relative to said frame, said wide-angle optical sensors being calibrated using a calibration grid so as to have overlapping fields of view to sense and produce image signals corresponding to substantially the entire image displayed on said electronic display device;

a computer controlling said test pattern generator and processing said image signals to perform a series of tests on said electronic display device; and

a display to provide a visual indication of the results of said series of tests.

14. A test and alignment system as defined in claim 13 wherein said close-up optical sensors include a plurality of rows of optical sensors, said optical sensors being angled in a direction towards said electronic display device.

15. A test and alignment system as defined in claim 14 further including at least one intermediate central row of optical sensors.

16. A test and alignment system as defined in claim 15 wherein said central row of optical sensors includes a vertically movable central optical sensor, said central optical sensor being positioned on said frame so that the field of view thereof includes the center of said image.

17. A test and alignment system as defined in claim 16 wherein said central optical sensor is pivotally mounted on said frame.

18. A test and alignment system as defined in claim 17 wherein said central optical sensor is pivotally mounted on a cantilever.

19. A test and alignment system as defined in claim 14 wherein said rows of optical sensors are supported on inclined rails mounted on said frame, said rails being vertically adjustable.

20. A test and alignment system as defined in claim 19 wherein the optical sensors in said rows are movable laterally along said respective inclined rails.

21. A test and alignment system as defined in claim 20 wherein the optical sensors in said rows include drive means to move said optical sensors laterally along said rails.

22. A test and alignment system as defined in claim 13 further including at least one wobulator mounted on said frame for creating an alternating magnetic field to bend electron beams within said electronic display device.

23. A test and alignment system as defined in claim 22 wherein said at least one wobulator includes at least one pair of laterally spaced electromagnets mounted on said frame and being energizable to generate a generally uniform alternating magnetic field, said alternating magnetic field encompassing generally the entire display screen of said electronic display device.

24. A test and alignment system as defined in claim 23 wherein said at least one wobulator includes a pair of vertically spaced, generally horizontal electromagnets and a pair of laterally spaced, generally vertical electromagnets, said pairs of electromagnets being energizable to generate alternating magnetic fields.

29. A test and alignment system as defined in claim 13 wherein at least one of said wide-angle and close-up optical sensors includes a CCD device and a fixed lens element, said CCD device being movable relative to said lens element to change the focus of said at least one optical sensor.

30. A test and alignment system as defined in claim 29 wherein said CCD device is mounted on a slide assembly responsive to a drive, said slide assembly being slidable along an axis parallel to an optical axis extending through said at least one optical sensor.

25. A test fixture for a test and alignment system for an electronic display device comprising:

a frame;

at least one optical sensor mounted on said frame to sense and produce image signals corresponding to an image displayed on an electronic display device positioned adjacent said test fixture; and

at least one wobulator mounted on said frame and including at least one pair of laterally spaced electromagnets, said electromagnets being energizable to generate a generally uniform alternating magnetic field generally encompassing the entire display screen of said electronic display device to bend electron beams within said electronic display device, said electromagnets being fixed to said frame outside of the field of view of said at least one optical sensor.

26. A test fixture as defined in claim 25 wherein said at least one wobulator includes a pair of vertically spaced, generally horizontal electromagnets and a pair of laterally spaced, generally vertical electromagnets, said pairs of electromagnets being energizable to generate alternating magnetic fields.

31. A test fixture for a test and alignment system for an electronic display device comprising:

a frame;

a plurality of close-up cameras mounted on said frame to sense and produce image signals corresponding to small areas of an image displayed on an electronic display device positioned adjacent said test fixture; and

a plurality of wide-angle cameras mounted on said frame behind said close-up cameras and being calibrated using a calibration grid so as to have overlapping fields of view, said wide-angle cameras sensing and producing image signals corresponding to substantially the entire image displayed on said electronic display device, said close-up cameras being positioned on said frame in front of said wide-angle cameras outside of the fields of view of said wide-angle cameras.

32. A test fixture as defined in claim 31 wherein said close-up cameras are arranged in an array including a plurality of vertically spaced rows, each of said rows including a plurality of close-up cameras, said close-up cameras being angled in a direction towards said electronic display device to compensate for convexities in the shape of said electronic display device.

33. A test fixture as defined in claim 32 wherein said rows of close-up cameras are supported on inclined rails mounted on said frame, said rails being vertically adjustable.

34. A test fixture as defined in claim 33 wherein said close-up cameras are movable along said respective inclined rails.

35. A test fixture as defined in claim 31 wherein each of said wide-angle and close-up cameras includes a CCD device and a fixed lens element, said CCD device being moveable relative to said lens element to change the focus of said camera.

36. A test fixture as defined in claim 31 wherein said calibration grid includes an identifier for each of said wide-angle cameras, each identifier defining a central point for the field of view of said respective wide-angle camera.

37. A test fixture as defined in claim 36 wherein said calibration grid includes an array of apertures formed in a sheet, each said identifier being constituted by a region of said sheet devoid of apertures.