Brightness modulation system for a plasma display device

• US 3,886,403 A
• Filed: 12/29/1972
• Issued: 05/27/1975
• Est. Priority Date: 12/30/1971
• Status: Expired due to Term

• Current Assignee: Hiroshi Furuta, Kenichi Owaki, Michihiro Shimuzi, Shozo Umeda, Tadatsugu Hirose
• Original Assignee: Hiroshi Furuta, Kenichi Owaki, Michihiro Shimuzi, Shozo Umeda, Tadatsugu Hirose
• Inventors: Shimuzi, Michihiro, Owaki, Kenichi, Umeda, Shozo, Furuta, Hiroshi, Hirose, Tadatsugu
• Primary Examiner(s): Kaufman, Nathan
• Application Number:
  US05/319,941
• Time in Patent Office: 879 Days
• Field of Search: 315/169TV
• US Class Current: 345/63
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/282 using DC panels
• CPC Class Codes: G09G 3/2922 Details of erasing
• CPC Class Codes: G09G 3/293 for address discharge
• CPC Class Codes: G09G 3/294 for lighting or sustain discharge
• CPC Class Codes: G09G 3/296 Driving circuits for producing the waveforms applied to the driving electrodes
• CPC Class Codes: H04N 3/125 using gas discharges, e.g. plasma

Abstract

A brightness modulation system for a plasma display panel device in which one picture element is made up of a plurality of discharge cells, the brightness levels of the plurality of discharge cells are made different from each other by impression of voltages of different phases or repetitive frequencies and the discharge cells are selectively combined, thereby to achieve a display composed of a plurality of graded tones.

Claims

1. A brightness modulation system for producing an iMage display with selectively controlled brightness level gradations on a plasma display device, said plasma display device having a plurality of X electrodes and a plurality of Y electrodes disposed to intersect each other with a discharge gas spaced therebetween whereby a plurality of discharge cells is formed at the intersections of the X and Y electrodes, the successive, adjacent electrodes of at least one of said pluralities of X and Y electrodes being arranged in groups and the electrodes of each such group defining corresponding combinations of discharge cells at the intersections thereof with the electrodes of the other of said pluralities of X and Y electrodes, each said combination of discharge cells comprising a display element of the said image display, the corresponding cells of each said combination being selectively and individually controllable to undergo respective, different and predetermined rates of discharge to produce corresponding, different individual brightness levels thereby to provide selective gradations of the brightness level of the display element formed by each such combination of discharge cells, said brightness modulation system comprising:

means for providing a number of different sustain signals corresponding to the number of discharge cells in each said combination thereof and of respectively different repetition rates, means for supplying said number of different sustain signals to the electrodes of said pluralities of X and Y electrodes corresponding to each said combination of discharge cells, thereby to sustain predetermined, different rates of discharges in the respectively corresponding cells of said combinations of cells, means for indicating the brightness level gradation to be displayed in each display element of the image display. means responsive to said indicating means for selecting the cells of the combination thereof corresponding to each display element which, in combination, provide the brightness level gradation for that corresponding display element as indicated by said indicating means, means for selectively establishing discharges in the cells selected by said selecting means of each said combination thereof, and said sustaining means sustaining discharges in those cells of each said combination in which discharges are selectively established by said means for selectively establishing discharges in accordance with the said predetermined different rates of discharges sustained by the respective, different sustain signals, thereby to sustain the gradation of brightness level for each said display element as indicated by said indicating means.

2. A brightness modulation system as recited in claim 1 wherein the successive, adjacent electrodes of each of said pluralities of X and Y electrodes are arranged in groups, the intersections of the electrodes of a group of one of said pluralities of X and Y electrodes with the electrodes of a group of the other of said pluralities of X and Y electrodes defining a corresponding combination of discharge cells comprising a display element of the said image display.

3. A brightness modulation system as claimed in claim 2 wherein each said group of X electrodes and each said group of Y electrodes includes n electrodes, defining thereby n discharge cells in the corresponding combination of discharge cells defined by the intersections of the electrodes of each said group of X electrodes with the electrodes of each said group of Y electrodes, whereby the number of brightness level gradations of each display element is 2n.

4. A brightness modulation system as recited in claim 2 wherein said sustain signal providing means provides sustain signals of different repetitive frequencies to the electrodes of each of said group of X electrodes and said group of Y electrodes associated with a given combination of discharge cells, for all said combinations, whereby each discharge cell of each said combination definEd by each group of one of said X and Y electrodes with a group of the other of said X and Y electrodes sustains a discharge at a different rate than the other discharge cells of that said combination.

5. A brightness modulation system as recited in claim 2, wherein said sustain signal providing means provides sustain signals of different pulse intervals to electrodes of each group of one of said pluralities of X and Y electrodes and provides sustain signals of a common repetition rate, but out of phase from one another, respectively, to the electrodes of each group of the other of said X and Y electrodes, whereby each discharge cell of each combination of discharge cells defined by the intersections of the electrodes of each group of one of said pluralities of X and Y electrodes with the electrodes of each group of the other of said pluralities of X and Y electrodes sustains a discharge a different number of times within a given time interval.

6. A brightness modulation system as recited in claim 2 wherein said brightness level gradation indicating means comprises:

means for receiving an analog picture signal to be displayed and converting the analog amplitude levels thereof representing the brightness of the picture to be displayed, to digital amplitude levels for the respectively corresponding display elements, and said selecting means is responsive to said digital signals for selectively establishing discharges in the cells of each said combination thereof in accordance with the brightness level gradations indicated by the digital signals for the respectively corresponding image display element.

7. A brightness modulation system as claimed in claim 2 for use with a television receiver receiving transmitted video signals and providing a corresponding analog picture signal defining brightness levels of a picture to be displayed, wherein said brightness level gradation indicating means comprises analog-to-digital converter means for converting the amplitude levels of said analog picture signal into corresponding digital signals, and said selecting means is responsive to said digital picture signals for selectively establishing discharges in the cells of each said combination thereof corresponding to each display element of the picture to be displayed, whereby an image display with brightness level gradations is provided.

8. A brightness modulation system for producing an image display with selectively controlled brightness level gradations on a plasma display device, said display device having a plurality of X electrodes and a plurality of Y electrodes disposed to intersect each other with a discharge gas spaced therebetween whereby a plurality of discharge cells is formed at the intersections of the X and Y electrodes, the successive, adjacent electrodes of each of said pluralities of X and Y electrodes being arranged in groups, and the intersections of the electrodes of each such group of one of said pluralities of X and Y electrodes with the electrodes of each such group of the other of said pluralities of X and Y electrodes defining corresponding combinations of discharge cells, each said combination of discharge cells comprising a display element of the said image display, the cells of each said combination being selectively and individually controllable to undergo respective, different and predetermined rates of discharge to produce corresponding, different and predetermined brightness levels thereby to provide selective gradations of the brightness level of the display element formed by each such combination of display cells, said brightness modulation system comprising:

means for providing a first set of energizing signals of a common repetition rate but displaced in phase, said first set including a number of energizing signals equal in number to the number of electrodes of each said group of one of said pluralities of X and Y electrodes, means providing at least a second set of energizIng signals of respectively different repetition rates, the signals of said second set being in phase with the signals of said first set, and being equal in number to the number of electrodes of each of said group of electrodes of the other of said pluralities of X and Y electrodes. means for applying the said number of energizing signals of said first set to respectively corresponding electrodes of each said group of said one of said pluralities of X and Y electrodes, means for indicating the brightness level gradation to be displayed in each display element of the image display, and means responsive to the indicated brightness level gradation for each display element for selectively applying the signals of said second set to respectively corresponding electrodes of each group of said other of said pluralities of X and Y electrodes corresponding to each said display element, thereby selectively to establish discharges in the cells of each said combination as to which the energizing signals applied to the corresponding X and Y electrodes of the groups associated with each said combination are in phase, and thereby to produce a brightness level gradation for the said combination of discharge cells in accordance with the indicated brightness level gradation for the corresponding display element.

9. A brightness modulation system as recited in claim 8 wherein said providing means provides a third set of energizing signals of respectively different repetition rates, each signal of said third set being in phase with one of said signals of said first set, and said applying means selects between the signals of said second and third sets for supply of the selected set of signals to the electrodes of each group of the other of said pluralities of X and Y electrodes to establish, selectively, discharges in the respectively corresponding discharge cells of the corresponding combinations thereof for producing respectively corresponding brightness level gradations in the associated picture elements of the display.

10. A brightness modulation system as recited in claim 9 wherein each of said first, second and third sets of energizing signals comprises two energizing signals differing as aforesaid, the signals of said second set being in phase with a first of said signals of said first set and the signals of said third set being in phase with the second of said signals of said first set.

11. A brightness modulation system as recited in claim 9 wherein said applying means is operable to select corresponding first ones of the signals of said second and third sets for supply to the electrodes of each said group of said one of said pluralities of X and Y electrodes and to select the second signals of both of said second and third sets for supply to the electrodes of each said group of said other of said X and Y electrodes.