CN2833779Y

CN2833779Y - Drive waveform formation circuit for improvement of image quality on color plasma display screen

Info

Publication number: CN2833779Y
Application number: CNU2005200795221U
Authority: CN
Inventors: 徐世文
Original assignee: Irico Group Electronics Co Ltd
Current assignee: Sichuan Sterope Orion Display Co., Ltd.
Priority date: 2005-10-14
Filing date: 2005-10-14
Publication date: 2006-11-01
Anticipated expiration: 2015-10-14

Abstract

The utility model discloses a drive waveform forming circuit for the improvement of the image quality of a color plasma display screen. The utility model comprises an energy recovery circuit a, a ramp rising edge forming circuit b and a ramp falling edge forming circuit c which are connected with signals of the output end of the energy recovery circuit a, a voltage Vyp input circuit d connected with signals of a scanning chip e and a display screen f connected with signals of the output end of the scanning chip e. The utility model is characterized in that the drive waveform forming circuit also comprises a comparator 4; one input end of the comparator 4 is connected with the-Vy end of a voltage, and the other input end is connected with the output end Yout of a Y drive circuit connected with a circuit; the output end of the comparator 4 is connected with the control input end of a field effect transistor 2 of the voltage Vyp input circuit d. The circuit of the utility model can eliminate residual time in an initialization period to perfect the work effects of triangular waves so as to improve the image quality of pictures.

Description

The drive waveforms of improving the color plasma display image quality forms circuit

Technical field

The utility model relates to the driving circuit of a kind of color plasma display (Plasma Display Panel:PDP), in particular, is a kind of triangular wave driving circuit of the PDP of improvement image quality.

Background technology

At present, the color plasma display [PDP] as new development in the large-scale flat-panel screens gets more and more people's extensive concerning.PDP utilizes gas discharge to realize graphic presentation, and its principle is the addressing electrode at the discharge cell that forms pixel, scan electrode, keep making alive on the electrode, allow discharge cell cause discharge and generation ultraviolet ray, the ultraviolet ray of generation is impacted red, green, blue three kinds of fluorescent powder, and form image.

As shown in Figure 1, PDP is driven by most height field, and represents the PDP gray level by the luminous number of each son field.Each son field is divided into during the initialization, and address period is during keeping.Be to wipe the discharge that during keeping, produces and make the wall electric charge of discharge cell even during the initialization; Address period is the signal that provides according to external image, adds addressing voltage for the discharge cell that will light; Be that the discharge cell that adds addressing voltage is kept discharge during keeping.

In order to improve the performance of PDP, during initialization, adopt the driving method (finishing) of triangular wave usually by driving circuit.The advantage of this driving method is the discharge that reduces during initialization, makes details in a play not acted out on stage, but told through dialogues brightness diminish, and improves contrast, the easier homogeneity that reaches of discharge cell in the address period, and improve image quality.

But when utilizing triangular wave to drive, following two shortcomings are arranged.

The first, as shown in Figure 2, after the negative edge of triangular wave drops to minimum point, III excess time is arranged, rise to the Vyp magnitude of voltage then.Excess time, III had a significant impact the effect of triangular wave.Excess time, III was long more, and the homogeneity of whole screen is poor more, can reduce the voltage remaining of display screen, finally can reduce image quality.

The second, in order to eliminate, can utilize as the A negative edge drive waveforms among Fig. 3 as the excess time among Fig. 2.The drive waveforms of A negative edge has been eliminated excess time substantially among Fig. 3, but through behind the certain hour, owing to being heated of devices such as field effect transistor, negative edge is affected, as the B among Fig. 3, C.

Summary of the invention:

The purpose of this utility model is to improve the deficiency of existing triangular wave driving circuit, and a kind of driving circuit of adjusting the negative edge slope of triangular wave is provided, thereby improves the image quality of PDP.

For achieving the above object, the utility model adopts following technical scheme to be achieved:

A kind of drive waveforms forms circuit, include energy recovery circuit, the slope rising edge that is connected with its output end signal forms circuit and the slope negative edge forms circuit, the input circuit of the voltage Vyp that is connected with the scanning chip signal, the display screen that is connected with scanning chip output signal, be characterized in, it also comprises a comparer, an input end of this comparer links to each other with voltage-Vy end, another input end is connected the Y driving circuit with circuit output terminal Yout links to each other, and the output terminal of this comparer then is connected on the control input end of field effect transistor of input circuit of voltage Vyp.By the switching time of control field effect transistor.Realize variation to the zero-time of screen electric capacity input Vyp voltage.

The beneficial effects of the utility model are by the adjustment to the slope of triangular waveform negative edge, eliminate the excess time during the initialization, make drive waveforms directly enter into address period, improve the work effect of triangular wave, thereby improve image quality.

Description of drawings:

Fig. 1 is a son synoptic diagram of three electrode AC plasma TVs.

Fig. 2 is triangular wave drive waveforms () synoptic diagram.Wherein, I-oblique wave rising edge, II-oblique wave negative edge, III-excess time, Vyp-plateau voltage ,-the Vy-negative pressure.

Fig. 3 is triangular wave drive waveforms (a two) synoptic diagram.

Fig. 4 is that the utility model drive waveforms forms circuit.Wherein, 1-electric capacity, 2-field effect transistor, 3-inductance, 4-comparer, 5-potentiometer, a-energy recovery circuit, b-oblique wave rising edge form circuit, c-oblique wave negative edge forms the input circuit of circuit, d-voltage Vyp, the output terminal that e-scans chip, f-screen, g-comparator circuit, Yout-Y driving circuit.

Fig. 5 is the drive waveforms synoptic diagram behind Fig. 4 circuit modification.

Embodiment

As shown in Figure 4, a kind of drive waveforms of improving the color plasma display image quality forms circuit, the slope rising edge that include energy recovery circuit a, is connected with its output end signal form circuit b and slope negative edge form circuit c, with the input circuit d that scans the voltage Vyp that chip e signal is connected, with scan the display screen f that chip e output end signal is connected; For the negative edge that detects triangular wave at any time arrives minimum point, on the driving circuit of present embodiment, increased a comparer 4, an input end of this comparer 4 links to each other with voltage-Vy end, another input end links to each other with the output terminal Yout of Y driving circuit, and the output terminal of this comparer 4 then is connected on the control input end of the field effect transistor 2 of controlling voltage VYP formation circuit d.

Above-mentioned energy recovery circuit a is made up of an electric capacity 1, an inductance 3 and three field effect transistor 2 parallel-seriess; The slope rising edge forms circuit b and is made up of an electric capacity 1, potentiometer 5, three field effect transistor 2 and tandem; The slope negative edge forms circuit c and is made up of a potentiometer 5 and two field effect transistor 2 and tandem; The input circuit d of voltage Vyp is made up of an electric capacity 1 and two field effect transistor 2 and tandem.

Circuit theory of the present utility model is by the switching time of control field effect transistor 2, to realize the variation to the zero-time of screen electric capacity input Vyp voltage; By utilizing circuit such as comparer to realize intellectuality, promptly when detecting the oblique wave negative edge and drop to minimum point, to screen electric capacity input Vyp voltage to the zero-time of screen electric capacity input Vyp voltage.When two input ends of comparer are identical, comparer output high level, the enforceable field effect transistor 2 of opening voltage Vyp end, as shown in Figure 5.Can prevent among Fig. 2 excess time III generation.

Claims

1. a drive waveforms of improving the color plasma display image quality forms circuit, include energy recovery circuit [a], the slope rising edge that is connected with its output end signal forms circuit [b] and the slope negative edge forms circuit [c], the input circuit [d] of the voltage Vyp that is connected with scanning chip [e] signal, the display screen [f] that is connected with scanning chip [e] output end signal, it is characterized in that, it also comprises a comparer [4], an input end of this comparer [4] links to each other with voltage-Vy end, another input end is connected the Y driving circuit with circuit output terminal Yout links to each other, and the output terminal of this comparer [4] then is connected on the control input end of field effect transistor [2] of input circuit [d] of voltage Vyp.