US5440340A
Expired / Lapsed
US
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Device for measuring characteristics of a color cathode ray tube
Assignee: Minolta Co Ltd
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Filing: 1993-06-15
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Granted: 1995-08-08
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Expires: 2013-06-15
Abstract
Abstract A CRT measurement device includes an image pickup device for producing an electrical image signal with respect to a light image displayed on the CRT, an optical system having a movable focusing lens for providing a light image of varied sharpness to the image pickup means in accordance with position of the focusing lens, a sharpness detector for detecting the sharpness of a picked up image based on an electrical image signal each time the focusing lens is moved, a focal position detector for detecting a focal position of the focusing lens providing a most sharpness light image, a driver for driving the focusing lens so as to move to the detected focal position, and calculator means for calculating a characteristic of the color CRT based on the image signal produced when the focusing lens is at the focal position. This device assures automatic and accurate focusing.
Inventors
- 👤 Katsutoshi Tsurutani
- 👤 Shinji Shimizu
- 👤 Teruo Ichikawa
- 👤 Kazunari Mizuguchi
- 👤 Mitsuo Washino
- 👤 Yoshiiku Kikukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:34
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
164 words
A device for measuring a characteristic of a color CRT having a display surface and a pickup region on the display surface, the device comprising: image pickup means for receiving a light image from the pickup region to produce an electrical image signal, the pickup region having a specified area and consisting of a plurality of subregions for measurement; an optical system having a focusing lens which provides a focused light image from the color CRT to the image pickup means; divider means for dividing the electrical image signal into a plurality of image signal portions corresponding to the plurality of subregions; selector means for selecting an image signal portion corresponding to a particular subregion; controller means for controlling the focusing lens based on the selected image signal portion to focus on the particular subregion; and calculator means for calculating a characteristic of the color CRT based on the selected image signal portion produced when the focusing lens is focused on the particular subregion.
Claim 2
Independent Claim
164 words
A device for measuring a characteristic of a color CRT having a display surface and a pickup region on the display surface, the device comprising: image pickup means for receiving a light image from the pickup region to produce an electrical image signal, the pickup region having a specified area and consisting of a plurality of subregions for measurement; an optical system having a focusing lens which provides a focused light image from the color CRT to the image pickup means; divider means for dividing the electrical image signal into a plurality of image signal portions corresponding to the plurality of subregions; selector means for selecting an image signal portion corresponding to a particular subregion; controller means for controlling the focusing lens based on the selected image signal portion to focus on the particular subregion; and calculator means for calculating a characteristic of the color CRT based on the selected image signal portion produced when the focusing lens is focused on the particular subregion.
Claim 3
Dependent Claim
22 words
A device as defined in claim 1, wherein the calculator means includes calculating means for calculating a misconvergence of the color CRT.
Claim 4
Dependent Claim
20 words
A device as defined in claim 1, wherein the light image is a measurement image having a predetermined pattern figure.
Claim 5
Dependent Claim
15 words
A device as defined in claim 3, wherein the measurement image is a crosshatch pattern.
Claim 6
Dependent Claim
17 words
A device as defined in claim 1, wherein the image pickup means includes a two-dimensional area sensor.
Claim 7
Dependent Claim
71 words
A device as defined in claim 1, wherein the controller includes: sharpness detector means for detecting a sharpness of a received image based on the electrical image signal each time the focusing lens is moved; focal position detector means for detecting a focal position of the focusing lens in order to provide a sharp light image; and driver means for driving the focusing lens to move to the detected focal position.
Claim 8
Dependent Claim
63 words
A device as defined in claim 1 further comprising: light image producing means for producing a light image on the display surface of the color CRT in accordance with a vertical synchronizing signal; and image pickup controller means responsive to the vertical synchronizing signal for controlling the image pickup means to pick up a light image in synchronism with the vertical synchronizing signal.
Claim 9
Independent Claim
164 words
A device for measuring a characteristic of a color CRT having a display surface and a pickup region on the display surface, the device comprising: a photoelectric sensor which receives a light image from the pickup region to produce an electrical image signal, the pickup region having a specified area and consisting of a plurality of subregions for measurement; an optical system having a focusing lens which provides a focused light image from the color CRT to the photoelectric sensor; a divider which divides the electrical image signal into a plurality of image signal portions corresponding to the plurality of subregions; a selector which selects an image signal portion corresponding to a particular subregion; a controller which controls the focusing lens based on the selected image signal portion to focus on the particular subregion; and a calculator means which calculates a characteristic of the color CRT based on the selected image signal portion produced when the focusing lens is focused on the particular subregion.
Claim 10
Independent Claim
164 words
A device for measuring a characteristic of a color CRT having a display surface and a pickup region on the display surface, the device comprising: a photoelectric sensor which receives a light image from the pickup region to produce an electrical image signal, the pickup region having a specified area and consisting of a plurality of subregions for measurement; an optical system having a focusing lens which provides a focused light image from the color CRT to the photoelectric sensor; a divider which divides the electrical image signal into a plurality of image signal portions corresponding to the plurality of subregions; a selector which selects an image signal portion corresponding to a particular subregion; a controller which controls the focusing lens based on the selected image signal portion to focus on the particular subregion; and a calculator means which calculates a characteristic of the color CRT based on the selected image signal portion produced when the focusing lens is focused on the particular subregion.
Claim 11
Dependent Claim
17 words
A device as defined in claim 8, wherein the calculator calculates a misconvergence of the color CRT.
Claim 12
Dependent Claim
20 words
A device as defined in claim 8, wherein the light image is a measurement image having a predetermined pattern figure.
Claim 13
Dependent Claim
15 words
A device as defined in claim 10, wherein the measurement image is a crosshatch pattern.
Claim 14
Dependent Claim
16 words
A device as defined in claim 8, wherein the photoelectric sensor includes a two-dimensional area sensor.
Claim 15
Dependent Claim
73 words
A device as defined in claim 8, wherein the controller includes: a sharpness detector means which detects a sharpness of a received image based on the electrical image signal each time the focusing lens is moved; a focal position detector which detects a focal position of the focusing lens in order to provide a sharp light image; and a lens driver which drives the focusing lens to move to the detected focal position.
Claim 16
Dependent Claim
68 words
A device as defined in claim 8, further comprising: a light image producer which produces a light image on the display surface of the color CRT in accordance with a vertical synchronizing signal; and an image pickup controller which controls the photoelectric electrical sensor for picking up a light image in synchronism with the vertical synchronizing signal, the image pickup controller being responsive to the vertical synchronizing signal.
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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) | 1998-08-07 | 1999-02-06 | 1999-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-07 | 2003-02-06 | 2003-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-07 | 2007-02-06 | 2007-08-08 | $7700.00 | Window Closed / Lapsed |