Patent US3737716A successfully refreshed from Google Patents.
US3737716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color purity adjustment utilizing a coil attached to the faceplate
Assignee: US Philips Corp
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Filing: 1971-03-24
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Granted: 1973-06-05
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Expires: 1991-03-24
Abstract
Abstract A method of adjusting the colour purity in colour picture display tubes the screen of which is provided with phosphor dots of luminescent material which are impinged upon by electron beams so that they luminesce in different colours. At least one of the electron beams is put into operation, while the picture to be displayed is without picture content and a coil or an annular magnet through which a direct current flows is placed in front of the screen of the tube. The purity adjusting members, that is to say, the purity magnets and/or purity coils and the securing means of the deflection unit are adjusted in such a manner that a ball of the colour corresponding to the said electron beams is placed in a fixed position within the coil. The coil may alternatively serve for degaussing metal parts of the picture tube.
Inventors
- 👤 J Gerritsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:43
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04; H01; H01J; H01J29/00; H01J29/003; H01J29/46; H01J29/82; H01J29/823; H01J9/00; H01J9/44; H01J2229/00; H01J2229/0007; H01J2229/0046; H01J2229/0053
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
86 words
A method of adjusting the color purity of a color display tube comprising activating at least one electron beam in in said tube without impressing any video signal thereon, whereby at least one distinct area is displayed on the tube screen, generating at least one pole of a magnetic field in front of said screen, and adjusting color purity members so that said area is in a predetermined position on said screen while keeping a deflection unit substantially in its proper position for deflecting said beam.
Claim 2
Independent Claim
86 words
A method of adjusting the color purity of a color display tube comprising activating at least one electron beam in in said tube without impressing any video signal thereon, whereby at least one distinct area is displayed on the tube screen, generating at least one pole of a magnetic field in front of said screen, and adjusting color purity members so that said area is in a predetermined position on said screen while keeping a deflection unit substantially in its proper position for deflecting said beam.
Claim 3
Dependent Claim
43 words
A method as claimed in claim 1 wherein said activating step comprises activating only one of said beams, and said generating step comprises generating a rotationally symmetrical magnetic field relative to a selected axis substantially coinciding with the axis of the display tube.
Claim 4
Dependent Claim
48 words
A method as claimed in claim 2 wherein said adjusting step comprises moving an alignment mark on said generating means in a direction perpendicular to a line connecting the center of an adjusted landing spot of the activated electron beam to a relevant phosphor dot on said screen.
Claim 5
Dependent Claim
49 words
A method as claimed in claim 2 wherein said generating step further comprises generating said magnetic field near an edge of said screen substantially symmetrical relative to a symmetrical axis or diagonal of said screen and placing an alignment mark on said generating means on said axis or diagonal.
Claim 6
Dependent Claim
30 words
A method as claimed in claim 1 wherein said generating step comprises generating two magnetic fields on a symmetry axis of said screen near the respective edges of said screen.
Claim 7
Independent Claim
130 words
A device for adjusting the color purity of a display tube having a screen, and neck, and at least one electron beam activated without a video signal to cause an area to luminesce on said screen, said circuit comprising a deflection unit disposed on said neck in the proper position for deflecting the electron beam from said gun, color purity adjusting means comprising means coupled to said deflection unit for securing said unit and color purity adjusting magnets disposed on said neck, and means for generating a magnetic field having a pole placed in front of said screen; whereby said adjusting means can be adjusted to place said area in a predetermined position on said screen while leaving said deflection unit in the proper position for deflection of said beam.
Claim 8
Independent Claim
130 words
A device for adjusting the color purity of a display tube having a screen, and neck, and at least one electron beam activated without a video signal to cause an area to luminesce on said screen, said circuit comprising a deflection unit disposed on said neck in the proper position for deflecting the electron beam from said gun, color purity adjusting means comprising means coupled to said deflection unit for securing said unit and color purity adjusting magnets disposed on said neck, and means for generating a magnetic field having a pole placed in front of said screen; whereby said adjusting means can be adjusted to place said area in a predetermined position on said screen while leaving said deflection unit in the proper position for deflection of said beam.
Claim 9
Dependent Claim
13 words
A device as claimed in claim 6 wherein said magnets comprise permanent magnets.
Claim 10
Dependent Claim
12 words
A device as claimed in claim 6 wherein said magnets comprise electromagnets.
Claim 11
Dependent Claim
15 words
A device as claimed in claim 6 wherein said field generating means comprises alignment marks.
Claim 12
Dependent Claim
24 words
A device as claimed in claim 6 wherein said field generating means comprises a substantially planar coil adapted to receive a direct current therethrough.
Claim 13
Dependent Claim
23 words
A device as claimed in claim 6 wherein said field generating means comprises a substantially annular permanent magnet having a unipolar annular side.
Claim 14
Dependent Claim
34 words
A device as claimed in claim 10 wherein said tube comprises a shadow mask tube and said coil comprises a removable coil means for degaussing said tube and any metal parts surrounding said tube.
Claim 15
Dependent Claim
38 words
A device as claimed in claim 12 further comprising means for supplying direct current to said coil; and a series circuit comprising said coil, a switch, a positive temperature coefficient thermistor, and means adapted to receive alternating current.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |