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EP0479508A2
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Video display apparatus including display device having fixed two-dimensional pixel arrangement
Assignee: Sharp Corp
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Filing: 1991-09-27
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Granted: —
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Expires: 2011-09-27
Abstract
Abstract A video display apparatus includes an LCD device of the active matrix type and an image memory having an arrangement and storage capacity corresponding to the two-dimensional pixel arrangement thereof. A necessary processing such as conversion of the number of scanning lines, time-base companding in the horizontal direction and so on is applied to the inputted video signal according to the format thereof and then it is written into the two-dimensional arrangement of the image memory. The data written into the image memory is read out by a clock of a fixed frequency within a period shorter than the writing period asynchronously with the writing operation. Then, the LCD is driven by the read data and an image is displayed on the pixel arrangement.
Inventors
- 👤 Naoki Kato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:37
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/01; H04N7/0117; H04N7/0122; G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G2310/00; G09G2310/02; G09G2310/0202; G09G2310/0205; G09G2310/0224; G09G2320/00; G09G2320/02; G09G2320/0271; G09G2320/0276; G09G2340/00; G09G2340/04; G09G2340/0407; G09G2340/0414; G09G2340/0421; G09G2340/0442; G09G2360/00; G09G2360/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
230 words
A video display apparatus comprising: a display device having a fixed two-dimensional pixel arrangement; an image memory capable of storing a video signal with a two-dimensional arrangement corresponding to the two-dimensional pixel arrangement of said display device and capable of asynchronous writing and reading operations; means for selectively receiving a video signal to be displayed among video signals of a plurality of formats; means for extracting horizontal and vertical synchronizing signals from said received video signal; means for generating at least one kind of clock having the phase synchronous with that of said extracted horizontal synchronizing signal and having a frequency selected according to the format of said received video signal; processing and writing means for processing said received video signal in response to said clock and writing said video signal into said image memory so as to place an effective display region of said video signal within the two-dimensional pixel arrangement of said image memory; means for generating a clock of a fixed frequency; means triggered by said extracted vertical synchronizing signal for reading the contents of said image memory within a fixed period in response to the clock of said fixed frequency asynchronously with the writing operation; and means for driving the display device so as to display an image on the two-dimensional pixel arrangement of said display device according to said read contents of the image memory.
Claim 2
Dependent Claim
43 words
The video display apparatus according to claim 1, wherein the fixed period in which the contents of said image memory are read out is set shorter than the shortest one among the vertical periods of said video signals of the plurality of formats.
Claim 3
Dependent Claim
32 words
The video display apparatus according to claim 2, wherein said image memory has an arrangement and storage capacity corresponding to said two-dimensional pixel arrangement for each video component constituting each video signal.
Claim 4
Dependent Claim
29 words
The video display apparatus according to claim 3, wherein the relative phase relationship of the start between the asynchronous writing and reading operations of said image memory is fixed.
Claim 5
Dependent Claim
20 words
The video display apparatus according to claim 1, further comprising means for determining the format of the received video signal.
Claim 6
Dependent Claim
39 words
The video display apparatus according to claim 5, wherein said processing and writing means includes means for writing said received video signal directly into said image memory according to the result of the determination by said format determining means.
Claim 7
Dependent Claim
46 words
The video display apparatus according to claim 5, wherein said processing and writing means includes means for performing scanning line number conversion and time-base companding in the horizontal direction of said received video signal according to the result of the determination by said format determining means.
Claim 8
Dependent Claim
48 words
The video display apparatus according to claim 7, wherein said conversion of the number of scanning lines and time-base companding in the horizontal direction are performed by writing and reading the video signal into/from a line memory using a plurality of clocks having periods of a prescribed ratio.
Claim 9
Dependent Claim
29 words
The video display apparatus according to claim 1, wherein said reading means includes means for applying a fixed signal processing to the video signal read from said image memory.
Claim 10
Dependent Claim
16 words
The video display apparatus according to claim 1, wherein said display device is an LCD device.
Claim 11
Dependent Claim
21 words
The video display apparatus according to claim 10, wherein said LCD device is an LCD device of the active matrix type.
Claim 12
Dependent Claim
127 words
A video display apparatus including a display device having a fixed two-dimensional pixel arrangement and an image memory having a storage arrangement and capacity corresponding to said two-dimensional pixel arrangement, processing means for applying such processing as conversion of the number of scanning lines and time-base companding in the horizontal direction to an inputted video signal according to the format thereof and for writing data constituted by the processed video signal into the image memory, means for reading out the data written into the image memory by a clock of a fixed frequency within a period shorter than the writing period asynchronously with the writing operation, and means for driving the display device by the read data so as to display an image on the pixel arrangement.
References Cited (Backward Citations)
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