Computer graphics processing and selective visual display system – Data responsive crt display control – Data responsive deflection control
Reexamination Certificate
2001-08-28
2004-01-27
Chow, Dennis-Doon (Department: 2675)
Computer graphics processing and selective visual display system
Data responsive crt display control
Data responsive deflection control
C345S014000, C348S511000, C348S747000, C315S370000
Reexamination Certificate
active
06683586
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to an apparatus and method of adjusting a horizontal position adjustment apparatus for a video display appliance, and more particularly, to an apparatus and method of adjusting a horizontal position that detects an overlap signal of a horizontal flyback pulse signal and a video signal, and adjusts the horizontal position using the overlap signal.
2. Description of the Prior Art
Video display appliances such as monitors include a horizontal position adjustment circuit in order to place the display image in the center of the screen.
Such conventional apparatuses and methods of adjusting a horizontal position for video display appliance are disclosed in U.S. Pat. No. 6,061,048 to Samsung Electronics Co., Ltd., entitled “Technique For Automatically Controlling The Centering Of monitor Screen”, and U.S. Pat. No. 5,801,767 to Amtran Technology Co., Ltd., entitled “Image Screen Automatic Adjustment for Video Monitor”.
The above-described patents disclose features in common with the present invention but do not teach or suggest the specifically recited technique for automatically adjusting a horizontal position of the video display appliance as in the present invention.
FIG. 1
is a block diagram showing a conventional horizontal position adjustment circuit.
The conventional horizontal position adjustment circuit includes a front/back porch counter
120
, a microprocessor
130
and a deflection circuit
140
.
The front/back porch counter
120
receives a horizontal flyback pulse
110
and an RGB video signal
100
and outputs front porch and back porch signals.
The microprocessor
130
includes an I/O port for receiving the front-porch and the back-porch from the counter
120
, and a processor for calculating and outputting a horizontal position value to place the display image in the center of the screen.
The deflection circuit
140
adjusts the horizontal position using the horizontal position value inputted from the microprocessor
130
to place the display image in the center of the screen.
FIG. 2
is a flowchart showing the firmware control procedure of the conventional horizontal position adjustment circuit. The conventional horizontal position adjustment circuit will be described in detail with reference to FIG.
2
.
First, at step
200
, if a new display mode is inputted or a user sets an automatic adjustment of a horizontal position, the front/back porch counter measures the front porch and the back porch using the horizontal flyback pulse and video signal and outputs the front porch and the back porch to the microprocessor at step
210
.
Then, at step
220
, the microprocessor calculates horizontal position data using the front porch and the back porch to place the position of the image in the center of the screen. At step
230
, the calculated horizontal position data is outputted to the deflection circuit.
At step
240
, the front/back porch counter measures again a new front porch and a new back porch, and checks whether or not the display image has been placed in the center of the screen.
If it is determined that the display image has not been placed in the center of the screen at step
250
, the horizontal position data is calculated again using the front porch and back porch measured at step
260
, and the procedure returns to step
230
.
Meanwhile, if it is determined that the display image has been placed in the center of the screen at step
250
, the procedure is ended.
However, the conventional horizontal position adjustment circuit has the disadvantage that it uses an expensive dedicated IC such as the front/back porch counter, and thus the circuitry becomes complicated with its cost increased.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a horizontal position adjustment apparatus for a video display appliance that effectively makes adjustments of a horizontal position using simple and inexpensive circuits without the expensive front/back porch counter.
The present invention achieves the above-identified object by providing a horizontal position adjustment apparatus that comprises a comparative circuit, a horizontal position correction circuit and a deflection circuit.
The comparative circuit receives a horizontal flyback pulse and a video signal and outputs a first and second overlap signals.
The first and the second overlap signals are generated when the horizontal flyback signal is inputted with the video signal at the same time. And, the first overlap signal is generated in the left side of the total range of the available horizontal position and the second overlap signal is generating in the right side.
The horizontal position correction circuit receives the first and the second overlap signals from the comparative circuit, calculates a mean value of a first horizontal position value and a second position value and outputs the mean value as an adjustment value of the horizontal position. The first horizontal position value represents the horizontal position when the first overlap signal is generated and the second horizontal position value represents the horizontal position when the second overlap signal is generated.
The deflection circuit adjusts the horizontal position based on the adjustment value.
According to the above described feature of the present invention, the horizontal position may be adjusted using the overlap signal of the horizontal flyback pulse and the video signals to displace the display image into the center of the screen.
Furthermore, the present invention also provides a method of adjusting horizontal position of a video display appliance comprises the steps of detecting a first overlap signal representing that a horizontal flyback pulse is overlapped with a video signal in a left side of a total range of an available horizontal position; detecting a second overlap signal representing that the horizontal flyback pulse is overlapped with the video signal in a right side of the total range of the available horizontal position; calculating a mean value of a first horizontal position value and a second horizontal position value, the first horizontal position value corresponding to the horizontal position when the first overlap signal is generated, and the second horizontal position value corresponding to the horizontal position when the second overlap signal is generated; and adjusting the horizontal position based on the mean value that is used as an adjustment value of the horizontal position.
REFERENCES:
patent: 4307422 (1981-12-01), Das
patent: 6259483 (2001-07-01), Jiang et al.
patent: 6266097 (2001-07-01), Jiang et al.
Chow Dennis-Doon
Jacobson & Holman PLLC
LG Electronics Inc.
LandOfFree
Apparatus and method of adjusting horizontal position for a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method of adjusting horizontal position for a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method of adjusting horizontal position for a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3206371