Patent Application
20070273616
The invention will be described in detail with reference to the following drawings in which like numerals refer to like elements.
a and 3b illustrate a timing diagram of a driving pulse supplied to scan electrodes and sustain electrodes in a sustain period of
Hereinafter, an implementation of this document will be described in detail with reference to the attached drawings.
Referring to
The plasma display panel 50 comprises a plurality of first electrode Y1 to Yn, and a plurality of second electrode Z1 to Zn, which are arranged in a column direction, and a plurality of third electrodes X1 to Xn arranged in a row direction. The first electrodes Y1 to Yn denote scan electrodes, the second electrode Z1 to Zn denotes sustain electrodes, and the third electrode X1 to Xm denote address electrodes, hereinafter.
The address driver 52 is controlled by a data clock DCLK and a second switching control signal SCS2 outputted from the timing controller 56 and supplies image data from an external device to the address electrodes X1 to Xm.
The scan driver 54 supplies a reset pulse and a scan pulse to the scan electrodes Y1 to Ym according to the first switching control signal SCS1 supplied from the timing controller 56. The scan driver 54 alternatively supplies a positive sustain pulse as a first pulse and a negative sustain pulse as a second pulse to the scan electrodes Y1 to Ym in order to induce a sustain discharge with the sustain electrodes Z1 to Zn that always receive bias voltage, preferably, a ground voltage GND.
The sustain electrodes Z1 to Zn disposed at the plasma display panel 50 are connected to a ground voltage source GND. That is, the plasma display apparatus does not comprise a driver for driving the sustain electrodes. Therefore, the manufacturing cost of the plasma display apparatus can be reduced. The plasma display apparatus may surely comprise a driver for driving the sustain electrodes for supplying a predetermined bias voltage to the sustain electrode.
The driving voltage generator 58 generates various driving voltages to generate a predetermined driving waveform, and supplies the generated driving voltage to the address driver 52 and the scan driver 54.
The timing controller 56 generates various switching control signals for generating a predetermined driving waveform and supplies the generated switching control signals to the address driver 52 and the scan driver 54. For example, the timing controller 56 generates a first switching signal SCS1 and supplies the generated first switching signal to the scan driver 54. The timing controller 56 generates the second control signal SCS2 and the data clock DCLK and supplies the second control signal SCS2 and the data clock DCLK to the address driver 52.
Hereinafter, a method of driving a plasma display apparatus according to an embodiment will be described.
As shown in
In the reset period or the setup period, a set-up pulse may be supplied to the scan electrodes Y1 to Yn of the plasma display panel 50. The set-up pulse induces a weak discharge in a discharge cell of the plasma display panel. In the set-down period, a set-down pulse falling from a sustain voltage Vs level to a predetermined voltage level may be supplied to the scan electrodes Y1 to Yn. Positive wall charge and negative wall charge can be sufficiently removed from a cell by inducing an erasing discharge between the scan electrodes Y1 to Yn and the address electrode X1 to Xm.
In the address period, a negative scan pulse falling from a scan reference voltage (Vsc) may be supplied to the scan electrodes Y1 to Yn. Furthermore, positive data pulse corresponding to the described scan pulse can be supplied to the address electrodes X1 to Xn. As the voltage difference between the scan pulse and the data pulse is added to the wall voltage generated in the reset period, an address discharge is induced in a discharge cell that receives the data pulse. The wall charge just enough for inducing the discharge is formed at a discharge cell selected by the address discharge when the sustain voltage (Vs) is supplied.
In the sustain period, the first pulse and the second pulse are alternately supplied to the scan electrodes Y1 to Yn. A predetermined bias voltage may be supplied to the sustain electrodes Z1 to Zn. Preferably, the sustain electrodes Z1 to Zn may sustain a ground level.
By sustaining the sustain electrode to have a predetermined bias voltage as described above, a driving circuit for driving the sustain electrodes can be shortened. Therefore, the manufacturing cost can be reduced.
As shown in
Further, as shown in
Hereinafter, the first and second pulses will be described in more detail with reference to
Although it is not shown in the accompanying drawings, an erasing period may be included after the sustain period in order to erase a wall charge after inducing the sustain discharge at a scan electrode or a sustain electrode.
a and
Referring to
In this case, the raising period El of the first pulse that raises from a negative voltage −Vs to a positive sustain voltage Vs is shorter than the falling period E2 of the second pulse that falls from the positive sustain voltage Vs to the negative voltage −Vs.
The raising period of the first pulse can be differently setup according to the driving characteristics of the plasma display panel such as a discharge characteristic of phospers. The driving characteristic of the plasma display panel, however, can be effectively improved by setting up the raising time of the first pulse longer than 300 ns and shorter than 1 ms.
The ratio between the raising period of the first pulse and the falling period of the second pulse can be differently setup according to the driving characteristics of the plasma display panel. The driving margin of the plasma display panel can be further secured by setting up the ratio between the raising period of the first pulse and the falling period of the second pulse to be larger than 1:1.2 and smaller than 1:1.5.
The raising period E1 or the falling period E2 can be expressed as a slop of a corresponding pulse. That is, it can be expressed as the absolute value of the slop of the first pulse is larger than that of the second pulse.
As described above, the brightness difference between electrode lines can be even further compensated by supplying the first pulse having the raising period E1 shorter than the falling period E2 of the second pulse to the scan electrodes.
Referring to
A magnitude of the predetermined bias voltage can be differently setup according to the driving characteristics of the plasma display panel. A manufacturing cost can be reduced by setting the magnitude of the predetermined bias voltage to be the ground level voltage. Because a driving circuit for driving the sustain electrodes can be shortened.
In this case, a first pulse bias period D1 where the first pulse sustains at the positive sustain voltage Vs is shorter than a second pulse bias period D2 where the second pulse sustains at the negative voltage −Vs.
The first pulse bias period D1 also can be setup differently according to the driving characteristics of the plasma display panel such as a discharge characteristic of phospers. The driving characteristic of the plasma display panel, however, can be effectively improved by setting up the first pulse bias period D1 longer than 500 ns and shorter than 2 ms.
Also, the ratio between the first pulse bias period D1 and the second pulse bias period D2 can be differently setup according to the driving characteristics of the plasma display panel. The driving margin of the plasma display panel can be further secured by setting up the ratio between the first pulse bias period and the second pulse bias period to be larger than 1:1.3 and smaller than 1:1.8.
As described above, the brightness difference between electrode lines can be even further compensated by supplying the first pulse having the bias period D1 shorter than the second pulse bias period D2 to the scan electrodes.
In the certain embodiment, the first pulse and the second pulse are alternately supplied to the scan electrodes and the sustain electrodes sustains the ground level in the sustain period. However, it is possible to supply the first pulse and the second pulse to the sustain electrodes and to sustain the scan electrodes at the ground level.
In the certain embodiment of the present invention, the driving pulse is supplied to the scan electrodes the raising time and the falling time of the driving pulse are controlled and supplied to the scan electrodes, and the bias period of the driving pulse is controlled and supplied to the scan electrodes, independently in the sustain period. However, the brightness difference between electrode lines or the driving characteristics of the plasma display panel can be further improved by controlling the raising time, the falling time, and the bias period of the driving pulse at the same time and supplying them to the scan electrodes.
The driving pulse according to the embodiments can be applied to a plasma display panel which has not only an electrode arrangement, scan electrode—sustain electrode—scan electrode—sustain electrode YZYZ, but also to other electrode arrangements, scan electrode—scan electrode—sustain electrode—sustain electrode YYZZ.
Referring to
On the contrary, in the sustain period, the first pulse and the second pulse is applied to the scan electrodes alternately and the sustain electrodes maintain the ground level voltage and a positive polarity pulse Pp is applied to the address electrodes.
In the sustain period, the first pulse having a positive sustain voltage Vs and the second pulse having a negative sustain voltage −Vs are applied to the scan electrode alternately so that an electric field intensity is strongly formed surrounding the scan electrode as show in
To apply the positive polarity pulse Pp to the address electrode interrupts generating the facing discharge between the scan electrode and the address electrode. As a result, the stable surface discharge between the scan electrode and the sustain electrode is generated.
In this case, the positive polarity pulse may be applied to the address electrode while the first pulse is applied to the scan electrode in the positive direction. An electric field of the same polarity is formed surrounding the scan electrode and the address electrode thereby so that it can induce generating the surface discharge between the scan electrode and the sustain electrode. Accordingly, the stable surface discharge between the scan electrode and the sustain electrode is further generated.
Although it is not shown in the accompanying drawings, a negative polarity pulse may be applied to the address electrode during the sustain period while the second pulse is applied to the scan electrode in negative direction.
An absolute value of the voltage of the above positive polarity pulse or the above negative polarity pulse is less than the voltage of the first pulse and the second pulse. Preferably, an absolute value of the voltage of the positive polarity pulse or the negative polarity pulse is substantially equal to a magnitude of a voltage of a data pulse which is applied to the second electrode during an address period.
Therefore, a cost of the driving circuit to drive the plasma display panel is reduced.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0047832 | May 2006 | KR | national |
