This application claims the priority of Korean Patent Application No. 10-2009-0093270 filed on Sep. 30, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a driver for a plasma display panel, and more particularly, to a driver for a plasma display panel having a separated board structure that can reduce parasitic resonance by shortening the length of a cable used for power transmission by separating a board having a Y electrode switch thereon from a board having an X electrode switch thereon.
2. Description of the Related Art
In general, a plasma display panel includes a plurality of unit cells, each of which includes a front panel, a rear panel and separation walls interposed therebetween. Each unit cell is filled with a main discharge gas, such as neon (Ne) or helium (He), and an inert gas containing a small amount of xenon (Xe). When this plasma display panel is discharged by high frequency voltage, the inert gas causes vacuum ultraviolet rays, and phosphors formed between the separation walls emit light, thereby displaying an image. Therefore, a power supply that applies high frequency voltage to the plasma display panel is necessarily employed.
The above-described plasma display panel is attracting attention as a display device in that it is thin and lightweight.
Due to price competition between liquid crystal displays and display devices using plasma display panels, there is a need for a reduction in product weight, thickness, size and manufacturing costs. This same applies to power supplies for plasma display panels.
As for these power supplies for plasma display panels, an integrated board structure in which a power conversion circuit, a Y electrode switch and an X electrode switch are arranged within a single board, is under consideration.
Power, which is switched through a Y electrode switch and an X electrode switch, needs to be transmitted to a Y electrode and an X electrode arranged at both sides of a plasma display panel. Here, cables are necessary to transmit the power. However, parasitic inductance components, being generated in proportion to the cable length, cause the distortion of waveforms of the power being transmitted, and undesirable heat is generated in the electrode switches.
An aspect of the present invention provides a driver for a plasma display panel having a separated board structure that can reduce parasitic resonance by reducing the length of a cable used for power transmission by separating a board having a Y electrode switch thereon from a board having an X electrode switch thereon.
According to an aspect of the present invention, there is provided a driver for a plasma display panel having a separated board structure, the driver including: a first board having a predetermined mounting area, and mounted with a power supply section having predetermined inductance and converting commercial AC power into predetermined driving power using the inductance, and a first electrode switch section, switching the driving power from a power conversion section and supplying the switched driving power to a first electrode of a plasma display panel; and a second board having a predetermined mounting area, physically separated from the first board, and mounted with a second electrode switch section receiving the driving power from the power supply section through a cable and switching the driving power to supply the switched driving power to a second electrode of the plasma display panel.
Power remaining after being consumed to drive the plasma display panel may be transmitted to the power supply section by resonance between the inductance of the power supply section and capacitance of the plasma display panel.
The power supply section may include the power conversion section receiving and switching power to convert the power into the driving power.
The power conversion section may perform a switching operation interlocked with a switching operation of the first and second electrode switch sections.
The power conversion section may include: a first power switch switching input power; a second power switch alternately switching the input power together with the first power switch and performing power conversion together with the first power switch; and a transformer transforming the power converted by the first and second power switches according to a turns ratio between a primary winding and a secondary winding to output the driving power.
The driver first electrode switch section and the second electrode switch section may switch the driving power according to a logic signal to charge and discharge the display panel with the driving power, the first electrode switch section may include first and second switches connected in series with each other, and the second electrode switch section may include third and fourth electrode switches connected in series with each other, the first electrode switch may be turned on and off together with the fourth electrode switch, the second electrode switch may be turned on and off together with the third electrode switch while the second and third electrode switches and the first and fourth electrode switches alternately perform switching operations, and a connection node of the first and second electrode switches may be connected to the first electrode of the plasma display panel, and a connection node of the third and fourth electrode switches is connected to the second electrode of the plasma display panel.
The driver first power switch may be turned on when the second electrode switch and the third electrode switch are turned on, the second power switch and the first power switch may be alternately turned on when the first electrode switch and the fourth power switch are turned on, and a connection terminal of the first and second power switches may be connected to the primary winding of the transformer.
A body diode of the second power switch may conduct during dead time when the first and second electrode switches and the third and fourth electrode switches are turned off to thereby form a path through which the remaining power is transmitted to the power conversion section from the first and second electrode switch sections, when voltage of the plasma display panel rises, a body diode of the first power switch may conduct during dead time when the first and second electrode switches and the third and fourth electrode switches are turned off to thereby form a path through which the remaining power is transmitted to the power conversion section from the first and second electrode switch sections, when voltage of the plasma display panel falls, and the inductance of the power supply section and the capacitance of the plasma display panel may produce an LC resonance when the path is formed.
The driver first and second electrode switches and the third and fourth electrode switches may be turned off, and the first power switch may be turned on and then turned off at a rising voltage interval of the plasma display panel, so that the body diode of the second power switch conducts,
The first and second electrode switches and the third and fourth electrode switches may be turned off, and the second power switch may be turned on and then turned off at a falling voltage interval of the plasma display panel, so that the body diode of the first power switch conducts.
The driver first electrode switch and the fourth electrode switch may be turned on, the second electrode switch and the third electrode switch may be turned off, and the second power switch may be turned on when a maximum voltage of the plasma display panel is maintained from the rising voltage interval to the falling voltage interval of the plasma display panel, and the second electrode switch and the third electrode switch may be turned on, the first electrode switch and the fourth electrode switch may be turned off, and the first power switch may be turned on when a minimum voltage of the plasma display panel is maintained from the falling voltage interval to the rising voltage interval of the plasma display panel.
The first electrode may be a Y electrode of the plasma display panel, and the second electrode may be an X electrode of the plasma display panel.
The first electrode may be an X electrode of the plasma display panel, and the second electrode may be a Y electrode of the plasma display panel.
The power supply section may include: a rectifying/smoothing unit rectifying and smoothing the commercial AC power; and a power factor correction unit correcting a power factor of the power from the rectifying/smoothing unit to supply DC power to the power conversion section.
The driver inductance may be leakage inductance of the transformer, inductance of an inductor element electrically connected in series between the connection node of the first and second power switches and the primary winding of the transformer, or composite inductance of the leakage inductance of the transformer and the inductance of the inductor element.
The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
Referring to
A power supply section 110 and a first electrode switch section 120 may be mounted on the first board A, while a second electrode switch section 130 may be mounted on the second board B.
Furthermore, a plurality of boards C, D, E and F may be further arranged on the rear surface of the plasma display panel module P. An image unit that controls an image being displayed on the plasma display panel may be mounted on the third board C. A logic unit that supplies a logic signal on the basis of the image control of the image unit may be mounted on the fourth board D. A buffer unit that transmits power from the first electrode switch section 120 to a first electrode a may be mounted on the fifth board E. An address buffer unit that transmits a signal to an address electrode of the plasma display panel may be mounted on the sixth board F.
The power supply section 110 of the first board A may receive commercial AC power to supply driving power having a predetermined DC voltage level. The first electrode switch section 120 switches the driving power, which is supplied by the power supply section 110, and supplies the switched driving power to the first electrode a of the plasma display panel, so that the plasma display panel may be charged or discharged with the power.
The second electrode switch section 130 of the second board B receives the driving power from the power supply section 110 of the first board A. Here, the second electrode switch section 130 receives the driving power from the power supply section 110 of the first board A through a cable Ca, and switches the driving power to supply the switched driving power to a second electrode b of the plasma display panel, so that the plasma display panel may be charged and discharged with the power.
The above-described driver according to this embodiment will now be described in detail with reference to the drawings.
Referring to
The power supply section 110 may include a power conversion unit 113 that switches and converts the power, a rectifying/smoothing unit 111 that rectifies and smoothes commercial AC power, and a power factor correction unit 112 that corrects a power factor of the rectified and smoothed power to supply DC power to the power conversion unit 113.
The power conversion unit 113 may include first and second power switches QR and QF that switch DC power VPFC and a transformer T that transforms a voltage level of the power, which is switched by the first and second power switches QR and QF.
The first and second power switches QR and QF may be half bridge type switches that are connected in series with input terminals of DC power from the power factor correction unit 112. Each of the first and second power switches QR and QF may have a body diode.
The transformer T may include a primary winding Np and a secondary winding Ns, each of which has a predetermined turns ratio, and the primary winding Np may be connected in parallel with the second power switch QF. Leakage inductance Lp and capacitance CR may be formed between the primary winding Np and the second power switch QF. The leakage inductance Lp may be leakage inductance of the transformer T itself or leakage inductance caused by an inductor element additionally connected.
The first electrode switch section 120 may include first and second electrode switches Ys and Yg that are connected in series with each other. A connection node between the first and second electrode switches Ys and Yg, which are connected in series with each other, may be electrically connected to one end of the secondary winding Ns of the transformer T and a first electrode of the plasma display panel Cp.
In the same manner, the second electrode switch section 130, which is mounted on the second board B, may include third and fourth electrode switches Xs and Xg that are connected in series with each other. A connection node of the third and fourth electrode switches Xs and Xg, which are connected in series with each other, may be electrically connected to the other end of the secondary winding Ns of the transformer T through a cable Ca and a second electrode of the plasma display panel Cp.
Here, the first electrode may be a Y electrode of the plasma display panel Cp, and correspondingly, the second electrode may be an X electrode of the plasma display panel Cp. In the same manner, the first electrode may be the X electrode of the plasma display panel Cp, and correspondingly, the second electrode of the plasma display panel Cp may be a Y electrode.
The first and second electrode switches Ys and Yg may be connected in parallel with the third and fourth electrode switches Xs and Xg. The switching operations of the first and second power switches QR and QF of the power conversion unit 113 are interlocked with those of the first and second electrode switches Ys and Yg and the third and fourth electrode switches Xs and Xg to thereby form an LC resonance path between the leakage inductance Lp of the transformer T and the capacitance Cp of the plasma display panel, so that power remaining after being consumed to drive the plasma display panel is transmitted to the power conversion unit 113 so as to replace the function of an existing Energy Recovery Circuit (ERC).
Here, the above-described replacing of the function of the existing ERC will now be described in detail with reference to the accompanying drawings.
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As described above, without using a separate Energy Recovery Circuit (ERC) that absorbs the power remaining after being supplied to the plasma display panel, the switching operation of a power conversion switch is interlocked with the switching operations of the Y electrode switch and the X electrode switch to form an LC resonance path of leakage inductance of the transformer and capacitance of the plasma display panel, so that the remaining power is transmitted to the power conversion unit, thereby replacing the function of the existing ERC and reducing the circuit area and the number of components of the circuit. Therefore, a reduction in weight, thickness and size and manufacturing costs can be achieved.
The individual components of the driver according to the embodiment may be separately mounted on a separated board in order to reduce parasitic resonance. That is, as described above, the power supply section 110 and the first electrode switch section 120 may be mounted on the first board A, while the second electrode switch section 130 may be mounted on the second board B. A reduction in parasitic resonance will be described in detail with reference to the accompanying drawings.
In
However, like the driver according to this embodiment that has a separated board structure, for example, when the power supply section 110 and the first electrode switch section 120 are mounted on the first board A, and the second electrode switch section 130 is mounted on the second board B, a cable only needs to have a length necessary to transmit power from the other end of the transformer T of the power supply section 110 to the second electrode switch section 130. Therefore, the cable length is reduced, compared to the cable length in
Therefore, a graph of
As described above, according to an exemplary embodiment of the invention, cable length used for power transmission is reduced by separating a board having a Y electrode switch formed thereon and a board having an X electrode switch formed thereon from each other to thereby reduce parasitic resonance, thereby preventing waveform distortion of power and reducing heat generation of switches in an integrated board structure for a reduction in weight, thickness and size.
As set forth above, according to exemplary embodiments of the invention, in a power supply supplying power to a plasma display panel, cable length used for power transmission is reduced by separating a board having a Y electrode switch formed thereon and a board having an X electrode switch formed thereon from each other to thereby reduce parasitic resonance, thereby preventing waveform distortion of power and reducing heat generation of switches in an integrated board structure for a reduction in weight, thickness and size.
While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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10-2009-0093270 | Sep 2009 | KR | national |
Number | Name | Date | Kind |
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7471047 | Ogawa | Dec 2008 | B2 |
20070165017 | Kubota et al. | Jul 2007 | A1 |
20080007490 | Onozawa | Jan 2008 | A1 |
Number | Date | Country |
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1020040097464 | Nov 2004 | KR |
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Korean Office Action for patent application No. 10-2009-0093270, issued Jan. 7, 2011. |
Number | Date | Country | |
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20110074299 A1 | Mar 2011 | US |