Computer graphics processing and selective visual display system – Display driving control circuitry – Display power source
Reexamination Certificate
1999-02-03
2001-04-03
Saras, Steven (Department: 2675)
Computer graphics processing and selective visual display system
Display driving control circuitry
Display power source
C345S066000, C315S169400
Reexamination Certificate
active
06211867
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plasma display panel (hereinafter, referred to as “PDP”) system, and more particularly, to a method and an apparatus which is capable of efficiently using power need to drive electrodes of the PDP.
2. Description of the Prior Art
In general, the PDP is classified into an AC type PDP and a DC type PDP according to a driving voltage applied to a discharge cell. The AC type PDP is driven by a sine wave alternating current or a pulse voltage whereas the DC type PDP is driven by a direct current. Since electrodes of the AC type PDP are covered with a dielectric and do not receive an ion damage according to the discharge, a life span of the electrodes of the AC type PDP is longer than that of the DC type PDP. Also, the AC type PDP memorizes a wall charge generated on a surface of the dielectric by a polarization into an inside cell.
A color AC type PDP which is mainly used for a broad screen television has a front panel and a rear panel. The front panel has a scan and sustentation electrode (hereinafter, referred to as Y) and a sustentation electrode (hereinafter, referred to as X) which are designed on a glass substrate in parallel. The rear panel has a cell space for sealing gas and an R-G-B address electrode (hereinafter, referred to as Z) which is designed on a rear glass substrate.
In order to drive the PDP, a DC high voltage has to be periodically applied between the X and Y electrodes to sustain the discharge between the X and Y electrodes. The two electrodes operate as a capacitor, so that a power applied to the two electrodes is not perfectly consumed. Accordingly, the PDP recovers an electric charge remained between the X and Y electrodes to decrease the power consumption of the PDP. A circuit recovers the applied power after applying the power to the X and Y electrodes and applies the recovered power to the X and Y electrodes in order to decrease the power consumption which is called to power recovery circuit.
The power recovered by the power recovery circuit is overlapped with the DC high voltage for driving the electrodes and is applied to the electrodes with the DC high voltage. At this time, for an efficient use of the power, a timing for applying the recovered power to the electrodes is very important concerning an applying timing of the DC high voltage.
In a case where the timing of the recovered power is faster than the applying timing of the DC high voltage, a waveform of the applied voltage is distorted and recycling rate of the recovered power decreases. On the contrary, in a case where the timing of the recovered power is slower than the applying timing of the DC high voltage, the recycling rate of the recovered power decreases since the DC high voltage is applied to the electrodes before the recovered power is efficiently applied.
However, since the applying timing of the recovered circuit is fixed by a configuration of a hardware of the power recovery circuit, the recovered power can not be efficiently used in the prior power recovery circuit.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention, in a case where the electrodes driving power of the PDP recovered by using the power recovery circuit is supplied to the electrodes, to provide a method and an apparatus that a user can variably set a supplying timing of the recovered electrodes driving power to be corresponded the characteristics of the PDP.
In order to achieve the above object, a method for controlling a power recovery of a plasma display panel television, which is capable of recovering a power applied to scan/sustentation electrodes, sustentation electrodes and address electrodes and applying the recovered power to the electrodes in response to a control signal, said method comprising the steps of:
1) setting a maximum variableness range of a recovery power supplying time;
2) memorizing first and second reference values which respectively represent starting and stopping points of the recovery power supplying time;
3) sequentially counting a predetermined clock signal from a starting point of the maximum variableness range within the maximum variableness range;
4) periodically comparing a counted value counted in step 3) with the first and second reference values, respectively, and calculating a first time when the counted value is equal to the first reference value and a second time when the counted value is equal to the second reference value; and
5) making the control signal for supplying the recovery power to the electrodes between the first time and the second time, wherein the first and second reference values are variably set from an outside.
In order to achieve the above object, an apparatus for controlling a supplying timing of a power recovery of a plasma display panel television, which is capable of recovering a power applied to scan/sustentation electrodes, sustentation electrodes and address electrodes and applying the recovered power to the electrodes in response to a control signal, said apparatus comprising:
a first means for generating a variableness range pulse which sets a maximum variableness range of a recovery power supplying time;
a second means for counting a first clock pulse and for periodically outputting the counted value in response to the variableness range pulse;
a third means for generating a first reference value which sets a rising timing of the control signal;
a fourth means for generating a second reference value which sets a falling timing of the control signal;
a fifth means for periodically comparing the counted value with the first reference value and for converting a logic level of an output signal from a low level into a high level when the counted value is equal to the first reference value;
a sixth means for periodically comparing the counted value with the second reference value and for converting the logic level of an output signal from the high level into the low level when the counted value is equal to the second reference value; and
a seventh means for logically multiplying the output signal from said fifth and the output signal from said sixth means to generate the control signal, wherein the first and second references values are variably set from an outside.
The third means has a first switching means for executing a switching operation by a first predetermined time set from an outside, and a first counting means for counting switching times of said first switching means and for generating the first reference value. The fourth means has a second switching means for executing a switching operation by a second predetermined time set from the outside, and a second counting means for counting switching times of said second switching means and for generating the second reference value. The first and second switching means have a toggle switch, respectively. The user can set an optimum supplying timing of the recovery power by operating the toggle switch until an optimum screen is displayed. Consequently, driving power of the electrodes can be efficiently used.
REFERENCES:
patent: 5424612 (1995-06-01), Kim
patent: 5555032 (1996-09-01), Kung
patent: 5559402 (1996-09-01), Corrigan, III
patent: 5654728 (1997-08-01), Kanazawa et al.
patent: 5739641 (1998-04-01), Nakamura et al.
patent: 6028573 (2000-02-01), Orita et al.
patent: 6034482 (2000-03-01), Kanazawa et al.
patent: 0 837 442 (1998-04-01), None
patent: 2 317 736 (1998-04-01), None
Anyaso Uchendu O.
Daewoo Electronics Co. Ltd.
Pillsbury & Winthrop LLP
Saras Steven
LandOfFree
Method and apparatus for controlling switching timing of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for controlling switching timing of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for controlling switching timing of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2468644