Television – Monitoring – testing – or measuring – Testing of image reproducer
Reexamination Certificate
1997-03-25
2001-06-26
Peng, John K. (Department: 2714)
Television
Monitoring, testing, or measuring
Testing of image reproducer
C348S190000, C348S180000, C348S806000
Reexamination Certificate
active
06252626
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the field of aligning and inspecting electronic display products including cathode ray tube (CRT) assemblies for computer monitors and television sets. More particularly, the invention relates to an aligning and inspection system for CRTs which can perform a comprehensive series of required tests at one station while simultaneously displaying the test results in a graphical user interface. The invention also relates to a digital color Charged Couple Device (CCD) camera device and a high sensitivity photodiode array device.
BACKGROUND OF THE INVENTION
In adjusting cathode ray tube (CRT) assemblies for computer monitors and television sets, precise mechanical, optical and electronic adjustments are required to provide optimum reproduction image quality. These adjustments include, but are not limited to, focus, purity of color, convergence of beams, color uniformity, geometry, and luminance. Each of these adjustments are typically performed independently from each other by a trained technician with the aid of a testing system. However, the testing systems previously used were deficient because they were unable to perform all of the tests needed to precisely align a CRT, were very slow and unable to provide real-time feedback for operator adjustments, were not sufficiently accurate and were not integrated to perform each of the measurements in an optimized sequence and then recheck and readjust measurements as required.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system and method for testing and aligning electronic display devices to obviate the problems and limitations of the prior art systems.
It is a further object of the present invention to provide an improved system and method for testing and aligning electronic display devices which allows for quick and easy mounting and dismounting of a CRT for test and/or alignment onto a test fixture.
Yet another object of the present invention is to provide an improved system and method for testing and aligning electronic display devices which can perform all of the tests needed to precisely align a CRT assembly and provide real-time feedback for operator adjustments.
Still another object of the present invention is to provide an improved system and method for testing and aligning electronic display devices which can integrate each of the measurements and make readjustments for measurements previously performed as required.
An additional object of the present invention is to provide an improved color CCD camera which can maintain focus irrespective of variations in the thickness and glass curvature of the CRT screen.
In accordance with the invention, there is provided a system for testing and aligning a CRT assembly. The system includes a video pattern generator connected to the CRT assembly for generating images of video test patterns on the CRT assembly. A plurality of optical sensor devices are mounted in a test fixture facing the CRT for sensing and producing image signals corresponding to the image of the video pattern on the CRT assembly. The system includes a circuit to synchronize and multiplex the image signals, to generate a digital signal and to test and align the CRT assembly in response to the digital signal. In addition, the system provides for automatic adjustment of the test fixture and the optical sensor devices mounted thereon to match the specifications of a specific geometry of CRT assembly being tested. The system also includes one or more wobulator devices generating an alternating magnetic field to assist in determining and adjusting the position of beam landing. The wobulator devices are mounted in close proximity with the front face of the CRT under test within the test fixture and are positioned to affect the screen area monitored by the optical sensor devices.
In further description of the invention, the terminology CRT or CRT assembly includes all means required to produce an image on a CRT, such as, but not limited to, the following elements: circuitry for generating electron beam(s), deflection elements and circuitry for horizontal and vertical scanning of electron beams(s), elements and circuitry to modify the relative position of electron beams and their position in relation to the mask or matrix of the CRT and elements and circuitry for focusing the electron beam(s).
According to the invention, one of the optical sensor devices includes a plurality of color CCD camera heads and first devices such as a motor in each color head to automatically focus the color CCD camera heads located on the test fixture with respect to the light-emitting surface of the CRT assembly. Further, second devices such as a motor in or adjacent to each color head are provided to individually position each of the color CCD camera heads on the test fixture with respect to the CRT assembly to match the specifications of a specific model of CRT being tested. Both the first and second devices are controlled by circuitry incorporating multiplexing and motor control functions.
According to the invention, the optical sensor devices include photodiode devices adapted for sensing the red, green or blue light emitted by the respective phosphors of the CRT, and utilized for measuring color purity and luminance. The photodiode devices may be secured to the color CCD camera heads, or applied independently, in conjunction with or without wobulator devices.
According to the invention a method of testing and aligning a CRT assembly comprises the first step of presenting a CRT assembly to an alignment system, and any or all further steps of: adjusting the focus of the CRT to meet focus specifications; adjusting the yoke of the CRT to meet at least preset Color Purity, Vertical Raster Shift and Yoke Rotation Test specifications; adjusting the CRT to meet Static Convergence Test specifications; adjusting the CRT to meet Dynamic Convergence Test specifications, and adjusting the CRT to meet various Image Geometry Test specifications, such as horizontal and vertical size and position, orthogonality and distortion. The method further includes the steps of: rechecking each of the CRT adjustments to insure that the CRT meets each of the specifications; and rejecting the CRT whenever one or more of the test specifications is not met.
According to the invention a color CCD camera is constructed of a lens, a CCD chip, and a motorized system for moving the CCD chip with respect to the lens to focus the CCD camera. The color CCD camera further includes a first motor mounted to the camera for moving the CCD chip with respect to the lens, structure for mounting the camera to a test rack, and a second motor for moving the camera with respect to the test rack. The second motor may be an integral part of the structure for mounting the camera to a test rack.
Further in accordance with the invention, a photodiode device adapted for measuring color purity and luminance comprises one to three photodiodes for sensing light intensity, one to three separate band pass optical filters, (one for red, one for green and one for blue) each located in front of one of the photodiodes, and one to three separate lenses that collect light. Each of the separate lenses is disposed in front of one of the optical filters for directing light from the selected area of the CRT through the respective optical filter onto a corresponding diode. Also, the photodiode device includes structure for mounting the photodiode device to the test rack and structure for moving the photodiode device with respect to the test rack. The structure for moving the photodiode device may be the same as the structure moving the CCD camera, if the photodiode device is mounted onto the CCD camera.
REFERENCES:
patent: 3962722 (1976-06-01), Ciciora
patent: 4330779 (1982-05-01), Wilensky et al.
patent: 4415921 (1983-11-01), Mulvanny et al.
patent: 4575753 (1986-03-01), Mistry et al.
patent: 4602272 (1986-07-01), Duschl
patent: 4688079 (1987-08-01), Fendley
patent: 4736251 (1988-04-01), Sasaoka
patent: 4751570 (1988-06-
Buckley Eric S.
Bukal Branko
Dawe Wayne G.
Lee Bruce W. C.
Noonan Andrew G.
Desir Jean W.
Image Processing Systems Inc.
Kinberg Robert
Peng John K.
Venable
LandOfFree
Test and alignment system for electronic display devices does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Test and alignment system for electronic display devices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Test and alignment system for electronic display devices will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2510962