US 7,746,295 B2Granted

Plasma display device having improved luminous efficacy

AssigneeHitachi, Ltd.

InventorsKenichi Yamamoto, Keizo Suzuki, Masatoshi Shiiki, Kyoji Kariya, Tomokatsu Kishi, Tetsuya Sakamoto, Takashi Sasaki, Takayuki Shimizu

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Abstract

There is provided a plasma display device capable of high luminous efficacy and stable driving for displaying images at various image display load factors. The plasma display device performs the sustain discharge for a light-emission display, and is configured to apply a sustain pulse voltage between a sustain electrode pair in a respective one of the plural discharge cells to generate a sustain discharge in a respective one of the following operating modes selected based upon use of the plasma display device: (a) generating a pre-discharge and then a main discharge; (b) generating a main discharge without a pre-discharge preceding the main discharge; and (c) switching between the mode (a) and the mode (b). The sustain voltage waveforms are used which compensate for an increase in voltage drop due to an increase in discharge current when the image display load factor is excessively increased.

Claims16

Dependent claims

A plasma display device comprising:

a plasma display panel including at least a plurality of discharge cells each having at least an electrode pair for generating a sustain discharge for a light emission display, wherein a sustain pulse voltage is applied between said electrode pair in a respective one of said plurality of discharge cells to generate the sustain discharge,
wherein at least a first-waveform voltage and a second-waveform voltage are provided for use as said sustain pulse voltage, and
said first-waveform voltage is composed of a first portion having a major portion of a first voltage and having a time duration T1 greater than 0 and a second portion having a major portion of a second voltage higher than said first voltage and having a time duration T2 greater than 0,
said second waveform voltage is composed of a third portion having a major portion of a third voltage and having a time duration T3 greater than 0 and a fourth portion having a major portion of a fourth voltage higher than said third voltage and having a time duration T4 greater than 0, said first-waveform voltage and said second-waveform voltage satisfy at least one of the following conditions (i) and (ii):
(i) at least one of the following inequalities is satisfied:
said third voltage>said first voltage or T3>T1, and
(ii) at least one of the following inequalities is satisfied:
said fourth voltage>said second voltage or T4>T2, and
wherein a pre-discharge and a main discharge continuous with the pre-discharge are generated when said first-waveform voltage having a time duration T1 being greater than zero is applied or when said second-waveform voltage is applied,
wherein one of said first-waveform and second-waveform voltages is selected based upon a load factor, which is a ratio of a number of lighted ones of said plurality of discharge cells during said sustain discharge to a total number of said plurality of discharge cells, and
wherein said plasma display device further comprises a table listing a relationship among said load factors, numbers of said sustain pulses of said first-waveform and second-waveform voltages, and luminance of said discharge cells, and at a boundary load factor at which a changeover is performed from said first-waveform voltage to said second-waveform voltage, numbers of sustain pulses of said first-waveform and second-waveform voltages are selected by using said table such that two luminances produced by discharges generated by said first-waveform and second-waveform voltages, respectively, are approximately equal to each other.

8 more elements

A plasma display device comprising:

a plasma display panel including at least a plurality of discharge cells each having at least an electrode pair for generating a sustain discharge for a light emission display, and a power recovery circuit,
wherein a sustain pulse voltage is applied between said electrode pair in a respective one of said plurality of discharge cells to generate the sustain discharge, and comprises at least a first-waveform voltage and a second-waveform voltage, and
said first-waveform voltage is composed of a first portion having a major portion of a first voltage and having a time duration T1 greater than 0 and a second portion having a major portion of a second voltage higher than said first voltage and having a time duration T2 greater than 0,
said second-waveform voltage is composed of a third portion having a major portion of a third voltage and having a time T3 greater than 0 and a fourth portion having a major portion of a fourth voltage higher than said third voltage and having a time duration T4 greater than 0,
said first waveform voltage and said second-waveform voltage satisfy at least one of the following conditions (i) and (ii):
(i) at least one of the following inequalities is satisfied:
said third voltage>said first voltage or T3>T1, and
(ii) at least one of the following inequalities is satisfied:
said fourth voltage>said second voltage or T4>T2, and
wherein said first and third voltages are established by using an inductance, which is not generated by said power recovery circuit, coupled to one of a power supply and ground potential, and a pre-discharge and a main discharge continuous with the pre-discharge are generated when said first-waveform voltage having a time duration T1 being greater than zero is applied or when said second-waveform voltage is applied,
wherein one of said first-waveform and second-waveform voltages is selected based upon a load factor, which is a ratio of a number of lighted ones of said plurality of discharge cells during said sustain discharge to a total number of said plurality of discharge cells, and
wherein said plasma display device further comprises a table listing a relationship among said load factors, numbers of said sustain pulses of said first-waveform and second-waveform voltages, and luminance of said discharge cells, and at a boundary load factor at which a changeover is performed from said first-waveform voltage to said second-waveform voltage, numbers of sustain pulses of said first-waveform and second-waveform voltages are selected by using said table such that two luminances produced by discharges generated by said first-waveform and second-waveform voltages, respectively, are approximately equal to each other.

9 more elements

A plasma display device comprising:

a plasma display panel including at least a plurality of discharge cells each having at least an electrode pair for generating a sustain discharge for a light emission display, wherein a sustain pulse voltage is applied between said electrode pair in a respective one of said plurality of discharge cells to generate the sustain discharge,
wherein at least a first-waveform voltage and a second-waveform voltage are provided for use as said sustain pulse voltage, and
said first-waveform voltage is composed of a first portion having a major portion of a first voltage and having a time duration T1 greater than 0 and a second portion having a major portion of a second voltage higher than said first voltage and having a time duration T2 greater than 0, said second waveform voltage is composed of a third portion having a major portion of a third voltage and having a time duration T3 greater than 0 and a fourth portion having a major portion of a fourth voltage higher than said third voltage and having a time duration T4 greater than 0, said first-waveform voltage and said second-waveform voltage satisfy at least one of the following conditions (i) and (ii):
(i) at least one of the following inequalities is satisfied:
said third voltage>said first voltage or T3>T1, and
(ii) at least one of the following inequalities is satisfied:
said fourth voltage>said second voltage or T4>T2,
wherein a pre-discharge and a main discharge continuous with the pre-discharge are generated when said first-waveform voltage having a time duration T1 being greater than zero is applied or when said second-waveform voltage is applied, and
wherein said first-waveform and second-waveform voltages include post-discharge voltages higher than said second and fourth voltages, respectively.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/583,849Filed 20 Oct 2006 · continuation
Priority: JP 2003-17364718 Jun 2003
Published: US 2007/0035474 A115 Feb 2007
Granted: 29 Jun 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G09G 3/2942
For lighting or sustain discharge: with special waveforms to increase luminous efficiency
G09G 3/2965
Driving circuits for producing the waveforms applied to the driving electrodes: using inductors for energy recovery
G09G 2360/16
Aspects of the architecture of display systems: calculation or use of calculated indices related to luminance levels in display data
G09G
Arrangements or circuits for control of indicating devices using static means to

Family

Application10/649,725Parent of this continuation · filed 28 Aug 2003
US 2007/0035474 A1Pre-grant publication · published 15 Feb 2007
US 7,145,522 B2Parent of this continuation
US 2004/0257304 A1Published application
US 7,746,295 B2This patent

From the US filing history. Foreign family members aren’t listed.

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