Flat display panel having internal power supply circuit for reducing power consumption

• US 7,068,264 B2
• Filed: 10/12/2001
• Issued: 06/27/2006
• Est. Priority Date: 11/19/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi Consumer Electronics Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Tomio, Shigetoshi, Matsui, Naoki, Yao, Shinpei
• Primary Examiner(s): Liang, Regina
• Assistant Examiner(s): DINH, DUC Q
• Application Number:
  US09/974,806
• Publication Number:
  US 20020044145A1
• Time in Patent Office: 1,719 Days
• Field of Search: 345211-212, 345 60- 68, 315/169.4
• US Class Current: 345/211
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2330/04 Display protection
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2927 Details of initialising
• CPC Class Codes: G09G 3/294 for lighting or sustain discharge
• CPC Class Codes: G09G 3/297 using opposed discharge type panels

Abstract

A flat display employs at least one high voltage different from logic voltages. The display has a voltage detection unit and a drive control signal control unit. The voltage detection unit is used to detect the high voltage. The drive control signal control unit is used to control drive control signals of the flat display in accordance with the detected high voltage. This arrangement eliminates charging currents that are applied to a display panel but have nothing to do on the actual displaying of data, or reactive currents due to unnecessary switching operations, thereby reducing power consumption.

Claims

1. A flat plasma display for displaying data in accordance with a high voltage and drive voltages produced from said high voltage, wherein said flat plasma display comprises:

a first high voltage decision unit determining whether or not said high voltage is at a specific value or within a specific range after a power supply is turned on and initialization is carried out;

a first drive voltage decision unit determining whether or not said drive voltages are at specific values or within specific ranges;

a second high voltage decision unit determining whether or not said high voltage is kept at the specific value or within the specific range after the start of a protective operation of an internal power supply circuit that generates said drive voltages;

a second drive voltage decision unit determining whether or not said drive voltages are kept at the specific values or within the specific ranges; and

a drive control signal control unit controlling drive control signals of said flat plasma display in response to the decided results of said first and second high voltage decision units and said first and second drive voltage decision units.

2. A flat plasma display as claimed in claim 1, wherein the control of said internal power supply circuit is carried out together with the control of said drive control signals in response to the decided results of said second drive voltage decision unit.

3. A flat plasma display as claimed in claim 1, wherein said flat plasma display is initialized when said second high voltage decision unit determines that said high voltage is not kept at the specific value or the specific range, and an internal power of said internal power supply circuit and said drive voltages are cut OFF when said second drive voltage decision unit determines that said drive voltages are not kept at the specific values or within the specific ranges.

4. A flat plasma display as claimed in claim 1, wherein said flat plasma display further comprises a time compensation unit for compensating for the time between the instant that said high voltage is applied until said drive voltages reach the specific values.

5. A flat plasma display as claimed in claim 1, wherein said specific value compared with said high voltage in said first high voltage decision unit differs from sold specific value compared with said high voltage in said second high voltage decision unit.

6. A flat plasma display as claimed in claim 1, wherein said flat plasma display comprises a three-electrode surface discharge AC plasma display.

7. A flat plasma display as claimed in claim 6, wherein said three-electrode surface discharge AC plasma display further comprises:

first and second electrodes arranged in parallel with each other, and

third electrodes orthogonal to said first and second electrodes, said first electrodes being commonly connected together and said second electrodes being arranged to define respective display lines, wherein said display has a surface discharge structure employing wall charges as a memory.

8. A flat plasma display as claimed in claim 7, wherein said three-electrode surface discharge AC plasma display further comprises:

a first substrate, said first and second electrodes being arranged in parallel to each other on said first substrate and paired for defining respective display lines;

a second substrate spaced apart from and facing said first substrate, defining a cavity therebetween, said third electrodes being arranged on said second substrate in orthogonal relationship to said first and second electrodes and displaced therefrom;

wall charge accumulating dielectric layers respectively covering the surfaces of said first and second electrodes;

a phosphor formed over said second substrate;

a discharge gas sealed in the cavity between said first and second substrates; and

cells formed at intersections where said first and second electrodes cross said third electrodes.

9. A flat plasma display employing a first high voltage for supplying a sustain pulse, comprising:

an internal power supply circuit generating a plurality of drive voltages from said first high voltage;

a voltage detection unit detecting respective levels of the first high voltage and other drive voltages which are produced by said first high voltage;

an internal power supply controlling unit producing power supply control signals controlling an operation of said internal power supply circuit according to the detected, respective levels of the first high voltage and the plural drive voltages,

wherein the internal power supply controlling unit produces a power supply control signal to stop the operation of the internal power supply circuit in a case when any one of the respective detected levels of the first voltage and the plural drive voltages is out of a predetermined level range.

10. A flat plasma display as claimed in claim 9, wherein said internal power supply controlling unit stops the operation of said internal power supply circuit by changing said power supply control signals in response to said detected first high voltage and other drive voltage.

11. A flat plasma display employing a first high voltage for supplying a sustain pulse, comprising:

a voltage detection unit detecting said first high voltage;

an internal power supply circuit receiving said first high voltage and generating another high voltage different from said first high voltage; and

an internal power supply controlling unit storing first and second specific values, the first specific value being greater than the second specific value, and selectively comparing the stored first and second specific values with the detected first high voltage, the first specific value being used when the first high voltage is rising and the second specific value being used when the first high voltage is falling, and controlling an operation of the internal power supply circuit in response to the compared result of the detected first high voltage,

where said internal power supply controlling until starts the operation of the internal power supply circuit when the detected first high voltage is higher than the first specific value, and stops the operation at the internal power supply circuit when the detected first high voltage is lower than the second specific value.

12. A flat plasma display as claimed in claim 11, wherein said internal power supply controlling unit starts a circuit operation through a control circuit if said detected first high voltage reaches said first specific value, and stops the circuit operation through said control circuit if said detected first high voltage is below said second specific value.

13. A flat plasma display employing a first high voltage for supplying a sustain pulse, comprising:

an internal power supply circuit generating a plurality of drive voltages from the first high voltage;

end

a voltage detection unit detecting at least one of the plural drive voltages;

wherein when any level of the plural drive voltages detected by the voltage detection unit is out of an predetermined level range, the operation of the internal power supply circuit, corresponding to the drive voltage which is detected to be out of the predetermined level range, is controlled to stop the operation.

14. A flat plasma display as claimed in claim 13, wherein the plural drive voltages are voltages which are supplied in a display electrode during a period different from a display discharge period.