EP0851401A2
Expired / Lapsed
EP
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Width adjustment circuit and video image display device employing thereof
Assignee: Panasonic Corp
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Filing: 1997-12-23
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Granted: —
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Expires: 2017-12-23
Abstract
Abstract A video display device for displaying a wide range of video signals which allows the user to freely set the screen display width and position. A request for adjusting the horizontal display width, vertical display width, horizontal display position, and vertical display position is made through a key circuit, and a microcomputer determines the state of the key circuit. The microcomputer then recalculates the horizontal expansion rate and vertical expansion rate of a scan converter, and send recalculated data to the scan converter and a PLL circuit. The scan converter and the PLL circuit converts signals to the number of picture elements displayable on the video display device in response to a request for adjustment, and changes the phase of the enable signal which indicates a display period of the video display device to adjust horizontal and vertical display positions.
Inventors
- 👤 Hirokatsu Yui
- 👤 Hiromitsu Torii
- 👤 Yoshikuni Shindo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:37
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/003; G09G2320/00; G09G2320/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A display width adjustment circuit comprising a key circuit for requesting expansion and compression in
horizontal and vertical display areas; a microcomputer for detecting the on and off states of
said key circuit and then detecting the frequency of the
horizontal and vertical synchronizing signals of the input
video signal; a PLL circuit which receives a setting for the frequency
division ratio from said microcomputer; an A/D converter which receives the analog video signal
and is controlled by said PLL circuit under the control of
said microcomputer; and a scan converter which receives the output signal from
said A/D converter, the horizontal and vertical synchronizing
signals, the clock signal from said PLL circuit, and the
control signal from said microcomputer, and outputs the video
signal for displaying a video image in a size required on a
required screen area of a video display device.
Claim 2
Dependent Claim
54 words
A display width adjustment circuit as defined in Claim
1, wherein the horizontal display width of a video image
displayed on said video display device can be freely adjusted
by having said scan converter change a horizontal conversion
rate in response to a request for the horizontal display
width adjustment from said key circuit.
Claim 3
Dependent Claim
58 words
A display width adjustment circuit as defined in Claim
1, wherein the horizontal display width of a video image
displayed on said video display device can be freely adjusted
by having said A/D converter change the number of sampling
per horizontal scanning period in response to a request for
the horizontal display width adjustment from said key circuit.
Claim 4
Dependent Claim
53 words
A display width adjustment circuit as defined in Claim
1, wherein the vertical display width of a video image
displayed on said video display device can be freely adjusted
by having said converter change a vertical conversion rate in
response to a request for the vertical display width
adjustment from said key circuit.
Claim 5
Dependent Claim
71 words
A display width adjustment circuit as defined in Claim
1, wherein the vertical display width of a video image
displayed on said video display device can be freely adjusted
by changing the number of sampling of the digitized signal
per horizontal scanning period and the number of lines of the
digitized signal per vertical scanning period in response to
a request for the vertical display width adjustment from said
key circuit.
Claim 6
Dependent Claim
65 words
A display width adjustment circuit as defined in Claim
1, wherein the horizontal display width can be free adjusted
and also the horizontal display width can be changed balanced
to the right and left by having said microcomputer change a
horizontal conversion rate in the scan conversion and also
change the phase of the enable signal indicating a display
period of said video display device.
Claim 7
Dependent Claim
65 words
A display width adjustment circuit as, defined in Claim
1, wherein the vertical display width can be free adjusted
and also the vertical display width can be changed balanced
to the top and bottom by having said microcomputer change a
vertical conversion rate in the scan conversion and also
change the phase of the enable signal indicating a display
period of said video display device.
Claim 8
Dependent Claim
200 words
A video display device employing horizontal and
vertical display width adjustment circuits which comprise: a key circuit for adjusting the horizontal display width,
vertical display width, and display position on a display
screen; a microcomputer for detecting the on and off states of
said key circuit and then detecting the frequency of the
horizontal and vertical synchronizing signal of the input
video signal, said microcomputer adjusting horizontal and
vertical display positions by changing the phase of the
enable signal which indicates a display period of said video
display device in response to a request for the display
position adjustment from said key circuit; a PLL circuit which receives a setting for a frequency
division ratio from said microcomputer in line with said
frequency; an A/D converter which receives the analog video signal
and is controlled by said PLL circuit under the control of
said microcomputer; and a scan converter which receives the output signal from
said A/D converter, the horizontal and vertical synchronizing
signal, the clock signal from said PLL circuit, and the
control signal from said microcomputer, and outputs the video
signal for displaying a video image in a size required on a
screen of the video display device.
References Cited (Backward Citations)
WO1995008132A1
Cited
EP1010164A1
Cited
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