Patent EP0404072A2 successfully refreshed from Google Patents.
EP0404072A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Active matrix liquid crystal display panel and method for compensating defective pixel in active matrix liquid crystal display panel
Assignee: NEC Corp
•
Filing: 1990-06-19
•
Granted: —
•
Expires: 2010-06-19
Abstract
Abstract An active matrix liquid crystal display panel is composed of a number of liquid crystal display elements arranged in the form a matrix, each of the liquid crystal display elements being composed of an individual display electrode, a common electrode, and a liquid crystal material sandwiched between the individual display electrode and the common electrode. The individual display electrode of each of the liquid crystal display elements is selectively activated through an associated active element. A liquid crystal display element connected to a defective active element is modified to become a half tone display element, so that the liquid crystal display element connected to the defective active element becomes overshadowed or inconspicuous when the display panel is in operation.
Inventors
- 👤 Shuji C/O Nec Corporation Ishihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 12:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/1306; G02F1/1309; G02F1/133; G02F1/136; G02F1/1362; G02F1/136259; G02F1/136268; G02F2201/00; G02F2201/50; G02F2201/506; G02F2201/508
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
127 words
A method for compensating a defective pixel in an active matrix liquid crystal display panel composed of a number of liquid crystal display elements arranged in the form a matrix, each of the liquid crystal display elements being composed of an individual display electrode, a common electrode and a liquid crystal material sandwiched between said individual display electrode and said common electrode, the individual display electrode of each of the liquid crystal display elements being selectively activated through an associated active element, the method comprising the step of modifying a liquid crystal display element connected to a defective active element into a half tone display element, whereby the liquid crystal display element connected to the defective active element becomes overshadowed when the display panel is in operation.
Claim 2
Independent Claim
127 words
A method for compensating a defective pixel in an active matrix liquid crystal display panel composed of a number of liquid crystal display elements arranged in the form a matrix, each of the liquid crystal display elements being composed of an individual display electrode, a common electrode and a liquid crystal material sandwiched between said individual display electrode and said common electrode, the individual display electrode of each of the liquid crystal display elements being selectively activated through an associated active element, the method comprising the step of modifying a liquid crystal display element connected to a defective active element into a half tone display element, whereby the liquid crystal display element connected to the defective active element becomes overshadowed when the display panel is in operation.
Claim 3
Dependent Claim
82 words
A method claimed in Claim 1 wherein each of liquid crystal display elements includes an individual color filter located between the liquid crystal material and said common electrode, and the modification of the liquid crystal display element is executed by irradiating a laser light into the color filter of the liquid crystal display element connected to the defective active element so that the color of said color filter is changed into gray which is at a mid-point tone between white and black.
Claim 4
Dependent Claim
98 words
A method claimed in Claim 1 wherein the modification of the liquid crystal display element is executed by applying heat into an individual display electrode of the liquid crystal display element connected to the defective active element so that a portion of the liquid crystal material sandwiched between said heated individual display electrode and said common electrode has a disturbed orientation whereby said portion of the liquid crystal material is rendered translucent so that the liquid crystal display element connected to the defective active element gives a gray which is at a mid-point tone between white and black.
Claim 5
Dependent Claim
45 words
A method claimed in Claim 3 wherein the heating of said individual display electrode is executed by applying to the defective active element, a voltage sufficient to heat said defective active element and hence the liquid crystal display element connected to the defective active element.
Claim 6
Dependent Claim
58 words
A method claimed in Claim 1 wherein the modification of the liquid crystal display element is executed by applying heat into a crystal display material portion of the liquid crystal display element connected to the defective active element so that said liquid crystal material portion has a disturbed orientation whereby said liquid crystal material portion is rendered translucent.
Claim 7
Dependent Claim
66 words
A method claimed in Claim 5 wherein the heating of said crystal display material portion of the liquid crystal display element connected to the defective active element is executed by applying to the liquid crystal display element connected to the defective active element, a laser beam sufficient to heat said crystal display material portion of the liquid crystal display element connected to the defective active element.
Claim 8
Independent Claim
238 words
A method for compensating a defective pixel in an active matrix liquid crystal display panel which includes a number of signal lines, a number of scan lines intersecting the signal lines to cooperate with the signal lines so as to form a matrix, a number of driving thin film field effect transistors arranged in the form of a matrix and positioned one by one at intersecting points between the signal lines and the scan lines, each of the driving thin film field effect transistors having a gate connected to one of the scan lines and a drain connected to one of the signal lines, and a number of liquid crystal display elements each having an individual display electrode, a common electrode opposing the individual display electrode, and a liquid crystal material between the individual display electrode and the common electrode, the individual display electrode of each of the liquid crystal display elements being connected to a source of a corresponding driving thin film field effect transistor so that the liquid crystal display elements are selectively driven by the associated driving thin film field effect transistors, the method comprising the step of modifying a liquid crystal display element connected to a defective driving thin film field effect transistor into a half tone display element, whereby the liquid crystal display element connected to the defective driving thin film field effect transistor becomes inconspicuous when the display panel is in operation.
Claim 9
Independent Claim
238 words
A method for compensating a defective pixel in an active matrix liquid crystal display panel which includes a number of signal lines, a number of scan lines intersecting the signal lines to cooperate with the signal lines so as to form a matrix, a number of driving thin film field effect transistors arranged in the form of a matrix and positioned one by one at intersecting points between the signal lines and the scan lines, each of the driving thin film field effect transistors having a gate connected to one of the scan lines and a drain connected to one of the signal lines, and a number of liquid crystal display elements each having an individual display electrode, a common electrode opposing the individual display electrode, and a liquid crystal material between the individual display electrode and the common electrode, the individual display electrode of each of the liquid crystal display elements being connected to a source of a corresponding driving thin film field effect transistor so that the liquid crystal display elements are selectively driven by the associated driving thin film field effect transistors, the method comprising the step of modifying a liquid crystal display element connected to a defective driving thin film field effect transistor into a half tone display element, whereby the liquid crystal display element connected to the defective driving thin film field effect transistor becomes inconspicuous when the display panel is in operation.
Claim 10
Dependent Claim
114 words
An active matrix liquid crystal display panel composed of a number of liquid crystal display elements arranged in the form a matrix, each of the liquid crystal display elements being composed of an individual display electrode, a common electrode and a liquid crystal material sandwiched between said individual display electrode and said common electrode, the individual display electrode of each of the liquid crystal display elements being selectively activated through an associated active element, wherein a liquid crystal display element connected to a defective active element is modified to give a half tone, whereby the liquid crystal display element connected to a defective active element becomes overshadowed when the display panel is in operation.
Claim 11
Dependent Claim
114 words
An active matrix liquid crystal display panel composed of a number of liquid crystal display elements arranged in the form a matrix, each of the liquid crystal display elements being composed of an individual display electrode, a common electrode and a liquid crystal material sandwiched between said individual display electrode and said common electrode, the individual display electrode of each of the liquid crystal display elements being selectively activated through an associated active element, wherein a liquid crystal display element connected to a defective active element is modified to give a half tone, whereby the liquid crystal display element connected to a defective active element becomes overshadowed when the display panel is in operation.
Claim 12
Dependent Claim
39 words
An active matrix liquid crystal display panel claimed in Claim 8 wherein said liquid crystal display element connected to a defective active element is modified to give a gray which is at a mid-point tone between white and black.
Claim 13
Dependent Claim
65 words
An active matrix liquid crystal display panel claimed in Claim 8 wherein each of liquid crystal display elements includes an individual color filter located between the liquid crystal material and said common electrode, and the color filter of the liquid crystal display element connected to the defective active element is modified to give a gray which is at a mid-point tone between white and black.
Claim 14
Dependent Claim
68 words
An active matrix liquid crystal display panel claimed in Claim 8 wherein a crystal display material portion of the liquid crystal display element connected to the defective active element has a disturbed orientation whereby said liquid crystal material portion is rendered translucent so that the liquid crystal display element connected to the defective active element gives a gray which is at a mid-point tone between white and black.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.