Plasma display apparatus having a driver protecting portion
View Patent ↗A plasma display apparatus which can surely prevent an overcurrent flowing in a driver for driving electrodes of a plasma display panel. A power source is shut off when an internal short-circuit state of a column electrode driver is detected based on a current or an electric potential on a power line in a column electrode driver detected during a light emission sustaining period.
1. A plasma display apparatus which has a plasma display panel that has a plurality of row electrode pairs corresponding to display lines and a plurality of column electrodes arranged so as to cross each of said row electrode pairs and in that a discharge cell functioning as a pixel is formed in each intersecting portion of said row electrode pairs and said column electrodes, and in which a display period of one field is constituted by a plurality of subfields each comprising an address period of time and a light emission sustaining period and said plasma display panel is driven, comprising:
a column electrode driver for generating pixel data pulses corresponding to a video signal during said address period and sequentially applying them to said column electrodes for each display line; and
a row electrode driver for generating scanning pulses synchronously with a timing of application of each of said pixel data pulses during said address period, sequentially applying them to one row electrode of each of said row electrode pairs, and alternately and repetitively applying sustaining pulses to all of said row electrode pairs during said light emission sustaining period,
wherein said column electrode driver comprises a power supplying circuit for generating a power potential having a predetermined electric potential and applying it to a power line and a data pulse driver for selectively applying said power potential on said power line to each of said column electrodes in accordance with said video signal of each display line to thereby form said pixel data pulses, and
said apparatus further has a driver protecting part for detecting a value of a current on said power line during said light emission sustaining period, thereby shutting off the power source of said column electrode driver based on said detected current value.
2. An apparatus according to claim 1 , wherein said driver protecting part comprises:
a power shut-off switch for connecting or disconnecting said power supplying circuit and said power line; and
a short-circuit detecting circuit for, when the value of the current on said power line detected during said light emission sustaining period is larger than a predetermined value, determining that an internal short-circuit has occurred in said data pulse driver, and controlling said power shut-off switch so as to disconnect said power supplying circuit and said power line.
3. An apparatus according to claim 1 , wherein said power potential is applied to each of said column electrodes and all of said column electrodes are set to a high impedance state for a predetermined period of time at the end of said address period, and thereafter, the high impedance state is maintained.
4. A plasma display apparatus which has a plasma display panel having a plurality of row electrode pairs corresponding to display lines and a plurality of column electrodes arranged so as to cross each of said row electrode pairs and in that a discharge cell serving as a pixel is formed in each intersecting portion of said row electrode pairs and said column electrodes, and in which a display period of one field is constituted by a plurality of subfields each comprising an address period and a light emission sustaining period and said plasma display panel is driven, comprising:
a column electrode driver for generating pixel data pulses corresponding to a video signal during said address period and sequentially applying them to said column electrodes for each display line; and
a row electrode driver for generating scanning pulses synchronously with a timing application of each of said pixel data pulses during said address period of time, sequentially applying them to one row electrode of each of said row electrode pairs, and alternately and repetitively applying sustaining pulses to all of said row electrode pairs during said light emission sustaining period,
wherein said column electrode driver comprises a power supplying circuit for generating a power potential having a predetermined electric potential and applying it to a power line and a data pulse driver for selectively applying said power potential on said power line to each of said column electrodes in accordance with said video signal of each display line thereby forming said pixel data pulses, said data pulse driver applying said power potential to each of said column electrodes and setting all or said column electrodes 10 a high impedance state for a predetermined period of time at the end of said address period, and thereafter, maintaining the high impedance state, and
said apparatus further has a driver protecting part for detecting an electric potential on said power line during said light emission sustaining period, thereby shutting off the power source of said column electrode driver based on said detected electric potential.
5. An apparatus according to claim 4 , wherein said driver protecting part comprises:
a power shut-off switch for connecting or disconnecting said power supplying circuit and said power line; and
a short-circuit detecting circuit for determining, when the electric potential on said power line detected during said light emission sustaining period is larger than a predetermined value, that an internal short-circuit has occurred in said data pulse driver, and controlling said power shut-off switch so as to disconnect said power supplying circuit and said power line.