JP2005121953A - Driving method of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving method of a plasma display panel which has a high light emission efficiency, high brightness and low power consumption. <P>SOLUTION: In the driving method of a plasma display panel having a surface plate 22 with a plurality of display electrodes 28 constituted of scanning electrodes 26 and first sustaining electrodes 25 and second sustaining electrodes 27 which are adjacent across the scanning electrodes 26, the plasma display panel is controlled so that the first sustaining discharge is generated by a voltage given between the first sustaining electrode 25 and the scanning electrode 26 and, thereafter, the second sustaining discharge is generated between the second sustaining electrode 27 and the scanning electrode 26 where a voltage smaller than the voltage between the first sustaining electrode 25 and the scanning electrode 26 is given. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for driving a plasma display panel.

  A plasma display panel (PDP) performs image display by exciting and emitting phosphors with ultraviolet rays generated by gas discharge. The PDP is configured by disposing a front plate 2 and a back plate 3 so as to form a discharge space 1 therebetween, as shown in FIG.

  A plurality of scan electrodes 4 and sustain electrodes 5 are formed on the surface plate 2. Scan electrode 4 and sustain electrode 5 are each formed by forming bus electrode 7 made of metal on transparent electrode 6. A first dielectric layer 8 is formed on the surface plate 2 so as to cover the scan electrodes 4 and the sustain electrodes 5, and a protective layer 9 is further formed on the first dielectric layer 8.

  A plurality of data electrodes 10 for writing display information are formed on the back plate 3, and a second dielectric layer 11 is formed on the back plate 3 so as to cover the data electrodes 10. A partition wall 12 is formed on the second dielectric layer 11 so as to be positioned between the data electrodes 10 in parallel with the data electrode 10, and a phosphor layer is formed on the surface of the second dielectric layer 11 and the side surface of the partition wall 12. 13 is formed. The data electrode 10 and the barrier rib 12 are arranged so as to be orthogonal to the scan electrode 4 and the sustain electrode 5, and a discharge cell serving as a light emission unit is formed at the intersection of the scan electrode 4, the sustain electrode 5 and the data electrode 10. .

  The discharge space 1 is filled with a mixed gas of neon (Ne) and xenon (Xe) as a discharge gas at a pressure of about 500 Torr. The partition wall 12 also has a function of partitioning adjacent discharge cells and preventing color discharge due to crosstalk of charged particles or the like related to gas discharge and color mixture due to optical crosstalk.

  FIG. 13 is a schematic plan view showing an example of the arrangement of the scan electrodes 4 and the sustain electrodes 5 in the conventional PDP so that the positional relationship among the scan electrodes 4, the sustain electrodes 5, the data electrodes 10 and the barrier ribs 12 can be understood. ing. A region surrounded by an alternate long and short dash line represents one discharge cell 14. As can be seen from this figure, in the conventional PDP, a display electrode composed of the scan electrode 4 and the sustain electrode 5 arranged with a discharge gap 15 is formed in each row, and the scan electrode 4 and the sustain electrode 5 adjacent to each other between the rows are formed. Are arranged with a gap 16 between the cells.

  The PDP described above is connected to a drive unit that drives the PDP to form a plasma display device.

  Next, the display operation of the PDP will be described with reference to FIG. 14 showing drive voltage waveforms. When displaying a television image, the image is composed of 60 frames per second in the NTSC system. When an image is displayed on this panel, the number of light emission pulses having a certain intensity is 1 by eight subfields weighted in binary, for example 1, 2, 4, 8, 16, 32, 64, 128. Construct a frame. Eight subfields display luminance according to their respective weights, and one or a plurality of subfields used for display are selected from these eight subfields to display predetermined luminance. Thus, gradation display is performed. Each subfield includes an initialization period, an address period, and a display period.

  In the initializing period, first, a sustain discharge in the previous subfield is terminated by applying a simultaneous simultaneous extinction pulse to the sustain electrode 5. Subsequently, an initializing discharge is applied to all the discharge cells 14 by applying an entire surface simultaneous lighting pulse to the scan electrode 4, and then an entire surface simultaneous extinguishing pulse is applied to the sustain electrode 5 to complete the initializing discharge. This prevents all the discharge cells 14 from being affected by the lighting state in the display period of the previous subfield.

  In the address period after the initialization period, a write scan pulse is applied to the scan electrode 4 in the first row, and at the same time, a write signal pulse is applied to the desired data electrode 10 to turn on the discharge cells 14 in the first row. Address discharge is caused in the discharge cell 14 to be caused to accumulate wall charges on the surface of the protective layer 9 and the surface of the phosphor layer 13. In all the rows after the second row, address discharge is caused in the discharge cells 14 to be turned on in the same manner. In this way, display information is written.

In the display period after the address period, a discharge sustain pulse of several tens kHz to several hundred kHz is applied between the scan electrode 4 and the sustain electrode 5 in the discharge cell 14 in which the address discharge has occurred in the address period. Only generate sustain discharge. The phosphor layer 13 is excited by ultraviolet rays generated by the sustain discharge, and visible light is generated to perform a display operation (for example, see Non-Patent Document 1).
Heki Uchiike and Shigeo Miko, “All about Plasma Display”, Industrial Research Council, Inc., May 1, 1997, p79-p80, p126-p127

  The demand for higher definition is increasing for PDP, and in order to meet this demand, it is necessary to narrow the arrangement pitch of the discharge cells 14, but when arranged at such a narrow pitch, the discharge cells Since the charged particles in 14 diffuse to the inner wall surface of the discharge cell 14, problems such as a reduction in luminous efficiency may occur.

  The present invention has been made to solve such problems, and an object thereof is to realize a method for driving a plasma display panel having high luminous efficiency, high luminance, and low power consumption.

  In order to achieve the above object, the plasma display panel driving method according to the present invention includes forming a plurality of display electrodes including a scan electrode and a first sustain electrode and a second sustain electrode provided adjacent to each other across the scan electrode. A method of driving a plasma display panel having a surface plate, wherein a first sustain discharge is generated by a potential difference applied between the first sustain electrode and the scan electrode, and then the first sustain electrode and the scan electrode The second sustain discharge is controlled to be generated between the second sustain electrode and the scan electrode to which a potential difference smaller than the potential difference is given.

  In order to achieve the above object, the plasma display panel driving method of the present invention includes a display electrode composed of a scan electrode and a first sustain electrode and a second sustain electrode provided adjacent to each other with the scan electrode interposed therebetween. A driving method of a plasma display panel having a plurality of surface plates, wherein a sustain pulse voltage is alternately applied to a scan electrode and a sustain electrode, and the sustain electrode is maintained with respect to the first sustain electrode and the second sustain electrode The pulse voltage is controlled so that the phase value is the same and the voltage value on the high potential side is different.

  The plasma display panel driving method of the present invention can reduce the environmental load in the sense of high brightness, low power consumption, and low power consumption by improving the light emission efficiency even with high definition.

  In other words, the invention according to claim 1 of the present invention is a surface plate on which a plurality of display electrodes each composed of a scanning electrode and a first sustaining electrode and a second sustaining electrode provided adjacent to each other with the scanning electrode interposed therebetween are formed. A method of driving a plasma display panel, comprising: generating a first sustain discharge by a potential difference applied between a first sustain electrode and a scan electrode; and then determining a potential difference between the first sustain electrode and the scan electrode. This is a driving method of a plasma display panel which controls to generate a second sustain discharge between a second sustain electrode and a scan electrode to which a small potential difference is applied.

  According to a second aspect of the present invention, there is provided a plasma display having a surface plate on which a plurality of display electrodes formed by a scanning electrode and a first sustaining electrode and a second sustaining electrode provided adjacent to each other with the scanning electrode interposed therebetween are formed. A driving method of a panel, wherein a sustain pulse voltage is alternately applied to a scan electrode and a sustain electrode, and the sustain pulse voltage for the first sustain electrode and the second sustain electrode, which are sustain electrodes, is in phase and high This is a method of driving a plasma display panel that is controlled so that the voltage values on the potential side are different.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the display electrodes are arranged such that the first sustain electrodes or the second sustain electrodes are adjacent to each other between adjacent discharge cells. It is characterized by arranging.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the sustain pulse voltage has a positive voltage value on the high potential side and a negative voltage value on the low potential side.

  According to a fifth aspect of the invention, in the invention of the second or fourth aspect, the sustain pulse voltage is applied to the first sustain electrode, which is a sustain electrode, and to the second sustain electrode. It is characterized by being replaced with a period.

  The invention according to claim 6 is the invention according to claim 5, wherein the predetermined period is a period of the sustain pulse voltage.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional perspective view showing a schematic configuration of a main part of a PDP according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 1 and 2, a PDP according to an embodiment of the present invention has a front plate 22 and a back plate 23, which are two substrates, facing each other so as to form a discharge space 21 between them. The peripheral portions of the face plate 22 and the back plate 23 are hermetically sealed with sealing glass. The discharge space 21 is filled with a discharge gas composed of a mixed gas of Ne and Xe at a predetermined pressure and mixing ratio.

The surface plate 22 has a plurality of display electrodes 28 formed by sequentially arranging a first sustain electrode 25, a scan electrode 26, and a second sustain electrode 27 on a substrate 24 made of glass. The first sustain electrode 25, the scan electrode 26, and the second sustain electrode 27 are configured by transparent electrodes 25a, 26a, and 27a and bus electrodes 25b, 26b, and 27b formed thereon, respectively. The transparent electrodes 25a, 26a, and 27a are made of indium tin oxide (ITO) or tin oxide (SnO ₂ ), and the bus electrodes 25b, 26b, and 27b are silver (Ag) thick films (thickness 2 μm to 10 μm), aluminum (Al ) A thin film (thickness 0.1 μm to 1 μm) or a chromium / copper / chromium (Cr / Cu / Cr) laminated thin film (thickness 0.1 μm to 1 μm).

Further, a first dielectric layer 29 (thickness 40 μm) made of low melting point glass mainly composed of lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ) or phosphorus oxide (PO ₄ ) is used as the first sustaining electrode 25. The scan electrode 26 and the second sustain electrode 27 are formed so as to cover. Further, a protective layer 30 (thickness: 500 nm) made of magnesium oxide (MgO) is formed on the first dielectric layer 29 so as to protect the first dielectric layer 29 from damage caused by the discharge plasma generated in the discharge space 21. ing.

  On the other hand, the back plate 23 has a plurality of data electrodes 32 formed on a substrate 31 made of glass in a direction orthogonal to the display electrodes 28 made up of the first sustain electrodes 25, the scan electrodes 26 and the second sustain electrodes 27. . The data electrode 32 is made of, for example, a silver thick film (thickness 2 μm to 10 μm), an aluminum thin film (thickness 0.1 μm to 1 μm), or a chromium / copper / chromium laminated thin film (thickness 0.1 μm to 1 μm). Then, a second dielectric layer 33 (thickness 5 μm to 20 μm) made of low melting point glass similar to the constituent material of the first dielectric layer 29 is formed on the substrate 31 so as to cover the data electrode 32. A partition wall 34 is formed in parallel with the data electrode 32 at a position between the data electrodes 32 on the second dielectric layer 33. Further, three color (red, green, and blue) phosphor layers 35 for color display are provided on the second dielectric layer 33 and on the side surfaces of the partition walls 34. Note that the second dielectric layer 33 is for improving the adhesion of the phosphor layer 35, and the function as a PDP can be obtained without the second dielectric layer 33.

  The discharge space 21 is partitioned into a plurality of sections by the partition walls 34. In the partitioned discharge space 21, the display electrodes 28 and the address electrodes 32 are arranged orthogonally, thereby unit light emission. A plurality of discharge cells 36 serving as regions are formed. In this PDP, a discharge is generated by a periodic voltage applied to the address electrode 32 and the display electrode 28, and an image is displayed by irradiating the phosphor layer 35 with ultraviolet rays resulting from the discharge and converting it into visible light. .

  FIG. 3 is a schematic diagram showing the positional relationship among the first sustain electrode 25, the scan electrode 26, the second sustain electrode 27, the data electrode 32, and the partition wall 34 in the PDP according to the embodiment of the present invention. FIG.

  As shown in FIG. 3, a plurality of display electrodes 28 including a first sustain electrode 25, a scan electrode 26, and a second sustain electrode 27 extend in the row direction and are arranged side by side to form one display electrode 28. Discharge gaps 37 are provided between the scanning electrode 26 and the first sustain electrode 25 and the second sustain electrode 27, respectively. Further, the data electrode 32 and the partition wall 34 are arranged to extend in the column direction, and a discharge cell 36 having a region indicated by an alternate long and short dash line is formed at the intersection of the display electrode 28 and the data electrode 32. The first sustain electrode 25 and the second sustain electrode 27 are arranged adjacent to each other with the inter-cell gap 38 between the discharge cells 36 adjacent to each other.

  And it arrange | positions so that the several discharge cell 36 may be formed between the surface plate 22 and the backplate 23, the peripheral part of the surface plate 22 and the backplate 23 is airtightly sealed with sealing glass, and the discharge space 21 Is filled with a discharge gas composed of a mixed gas such as Ne and Xe at a predetermined pressure and mixing ratio, thereby completing the PDP.

  That is, the PDP according to the present embodiment is configured by forming a plurality of discharge cells 36 between the surface plate 22 and the back plate 23, and the first sustain electrode is formed on the surface plate 22 that is one substrate. 25, the display electrode 28 composed of the scan electrode 26 and the second sustain electrode 27 is formed so as to be arranged for each discharge cell 36.

  Next, the display operation of the PDP will be described using the driving voltage waveform shown in FIG. This shows only the drive waveform in the display period, which is a different part from the conventional drive voltage waveform shown in FIG. That is, in the initialization period and the address period other than the display period, in the present embodiment, the first sustain electrode 25 and the second sustain electrode 27 are driven in the same manner as that for the sustain electrode 5 shown in FIG. Basically, the same drive voltage as that applied to the scan electrode 4 shown in FIG. 14 is applied to the scan electrode 26. However, since the electrode structure is greatly different from the conventional one, not all of the details of the voltage waveform are the same.

  A thin solid line and a thick broken line in FIG. 4 represent voltage waveforms of sustaining pulses applied to the first sustaining electrode 25 and the second sustaining electrode 27, respectively, when the scanning electrode 26 is set to the reference potential. Their features are that the phase is the same and the voltage value on the high potential side is different. That is, the voltage value VHi on the high potential side of the sustain pulse voltage applied to the first sustain electrode 25 is different from the voltage value VLo on the high potential side of the sustain pulse voltage applied to the second sustain electrode 27, compared to VHi. It is in lowering VLo.

  Here, FIG. 4 shows an example in which the voltage value on the high potential side of the sustain pulse voltage is positive and the voltage value on the low potential side is negative. However, the voltage value on the low potential side may be zero. . Further, although the voltage value on the low potential side of the sustain pulse voltage is the same voltage value for both the first sustain electrode 25 and the second sustain electrode 27, the voltage value on the low potential side is also the voltage value on the high potential side. Similar to, different ones may be used. Moreover, although the absolute value of the voltage value on the low potential side is the same as the voltage value VHi on the high potential side, a value larger than VHi may be set as the absolute value of the voltage value on the low potential side. Absent. Further, even if the phase of the application timing of the sustain pulse voltage is shifted by 180 degrees and the positive / negative of the voltage is reversed, as shown in FIG. 5, the first sustain electrode 25 and the second sustain electrode are compared with FIG. 27, the sustain pulse voltage applied to 27 may be interchanged.

  FIG. 6 shows a waveform of a drive voltage for driving the PDP according to the present embodiment. As for the drive voltage waveform in the display period, the voltage waveform of the scan electrode 26 is the same as that of the conventional example shown in FIG. 14, and the first sustain electrode 25 and the second sustain electrode 27 which are sustain electrodes are A drive voltage that satisfies the above-described conditions described with reference to FIG. 4 or FIG. 5 is applied.

  The driving state in the above configuration is considered as follows. First, a first sustain discharge is generated between the first sustain electrode 25 and the scan electrode 26 to which a sustain pulse voltage higher than that of the second sustain electrode 27 is applied. The charged particles generated by the first sustain discharge, the excited particles, and the like are primed. As a result, the second sustain electrode 27 and the scan electrode 26 to which only a sustain pulse voltage lower than the first sustain electrode 25 is applied. The second sustain discharge also starts between the two.

  Here, comparison of evaluation between the PDP according to the present embodiment and the conventional PDP was performed by actually manufacturing the PDP. The driving voltage waveform of the PDP according to the present embodiment is as shown in FIG. 6, and the driving voltage waveform of the conventional PDP is as shown in FIG. Then, only the central area of the PDP was displayed in white (background was displayed in black), and the power consumption was examined while maintaining the same emission luminance.

  As a result, it has been found that the power consumption of the conventional PDP is about 1.4 times that of the PDP according to the present embodiment. Further, the measurement result of the discharge current is schematically shown in FIG. The thick line is the result of the PDP in the present invention, and the thin line is the result of the PDP in the conventional example. It can be seen that the discharge current of the PDP according to the present embodiment has a lower peak, a wider peak, and a longer time for the discharge current to flow than the discharge current of the conventional PDP. The peak broadening of the discharge current means that the second sustain discharge is generated by the first sustain discharge. Depending on design conditions, the peak of the discharge current may be two peaks as schematically shown in FIG.

  In the above evaluation results, the reason why the power consumption of the PDP according to the present embodiment is reduced and the light emission efficiency is improved is as follows. That is, the PDP uses light emission due to a transition between the excitation level and the ground level. For this light emission, there is a region where the light emission luminance is saturated with respect to the discharge current, so it is desirable to drive the panel at a low current level from the viewpoint of light emission efficiency. Here, since the PDP according to the present embodiment can be driven with a low discharge current, and the decrease in light emission luminance associated with the low discharge current can be compensated by an increase in discharge time, the light emission efficiency is improved. it is conceivable that.

  Here, VLo and VHi shown in FIG. 4 and FIG. 5 are preferably VLo ≧ 0.75 VHi based on the study conducted by the present inventors in terms of improving efficiency while maintaining luminance. Further, in the display period of each subfield, if the voltage of the second sustain electrode 27 is raised to the same value as the voltage of the first sustain electrode 25 only for the first several cycles of the sustain pulse voltage, stable without error discharge, That is, it has been found that a sustain discharge with a wide design margin can be realized.

  FIG. 8 shows another example of the drive voltage waveform. This is an example in which the voltage value on the high potential side of the sustain pulse voltage is positive and the voltage value on the low potential side is negative. By setting the sustain pulse voltage to such a waveform, the voltage value applied to each of the scan electrode 26, the first sustain electrode 25, and the second sustain electrode 27 can be reduced while maintaining the relative voltage difference between the scan electrode 26, the first sustain electrode 25, and the second sustain electrode 27. The efficiency can be further improved.

  Here, considering the conditions under which the discharge is maintained in the display period, the wall charge amount between the scan electrode 26 and the second sustain electrode 27 is higher than the voltage between the first sustain electrode 25 and the scan electrode 26. Decreases almost in proportion to. Therefore, in order to maintain a stable sustain discharge, the sustain pulse voltage after a half cycle needs to equalize the voltage between both electrodes, and it is necessary to accumulate substantially the same amount of wall charges after the discharge. Even if the voltage between the electrodes is the same due to the difference in the wall charge amount, two discharges are generated by one discharge sustaining pulse.

  In the electrode configuration of the PDP according to the present embodiment, strong light emission (first discharge) is generated between the first sustain electrode 25 and the scan electrode 26, and weak light emission (first discharge) is generated between the scan electrode 26 and the second sustain electrode 27. Secondary discharge) always occurs. Accordingly, the deterioration rate of the phosphor layer 35 becomes unbalanced, and the lifetime of the panel is limited by the deterioration of the phosphor layer 35 in the vicinity between the first sustaining electrode 25 and the scanning electrode 26, resulting in a shortened lifetime. . Therefore, as shown in FIGS. 9 and 10, when the sustain pulse voltages applied to the first sustain electrode 25 and the second sustain electrode 27 are switched in synchronization with the sustain pulse voltage cycle, strong discharge and weak discharge are generated. Since the position is switched, the life of the PDP is improved. The drive voltage waveform shown in FIG. 9 is an improvement of the drive voltage waveform shown in FIG. 6, and the drive voltage waveform shown in FIG. 10 is an improvement of the drive voltage waveform shown in FIG. In addition, the replacement period of these discharge sustain pulses is not limited to the above, and the same effect can be obtained if they are periodically replaced. Also, the period need not be particularly constant.

  Further, in the electrode configuration shown in FIG. 3, stray capacitance exists in the inter-cell gap 38 by applying different voltages between the first sustain electrode 25 and the second sustain electrode 27 in the display period. There may be a problem that power loss (reactive power) increases power consumption. In such a case, as shown in FIG. 11, the plurality of display electrodes 28 are arranged so that the first sustain electrodes 25 or the second sustain electrodes 27 are adjacent to each other between the adjacent discharge cells 36. Can be solved.

  As described above, the present invention can provide a method for driving a plasma display panel with high luminance, low power consumption, and low environmental load in the sense of improving luminous efficiency even with high definition. it can.

1 is a cross-sectional perspective view showing a schematic configuration of a main part of a plasma display panel according to an embodiment of the present invention. AA arrow sectional view in FIG. The fragmentary top view for demonstrating arrangement | positioning of the electrode in the plasma display panel by one embodiment of this invention The figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention Similarly, the figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention Similarly, the figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention The figure which shows the state of the discharge current in the plasma display panel typically Similarly, the figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention Similarly, the figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention Similarly, the figure which shows the drive voltage waveform of the plasma display panel by one embodiment of this invention Schematic plan view for explaining the arrangement of electrodes in a plasma display panel according to an embodiment of the present invention Partial sectional perspective view showing a schematic configuration of a conventional plasma display panel Schematic plan view for showing the arrangement of electrodes of a conventional plasma display panel The figure which shows the waveform of the drive voltage of the conventional plasma display panel

Explanation of symbols

21 Discharge Space 22 Front Plate 23 Back Plate 25 First Sustain Electrode 26 Scan Electrode 27 Second Sustain Electrode 28 Display Electrode 32 Data Electrode 34 Bulkhead 36 Discharge Cell

Claims (6)

A driving method of a plasma display panel having a surface plate on which a plurality of display electrodes formed by a scan electrode and a first sustain electrode and a second sustain electrode provided adjacent to each other with the scan electrode interposed therebetween, the first sustain The second sustain electrode and the scan electrode to which a potential difference smaller than the potential difference between the first sustain electrode and the scan electrode is applied after the first sustain discharge is generated by the potential difference applied between the electrode and the scan electrode And driving the plasma display panel so as to generate a second sustain discharge between the two. A method for driving a plasma display panel having a surface plate on which a plurality of display electrodes each formed by a scan electrode and a first sustain electrode and a second sustain electrode provided adjacent to each other with the scan electrode interposed therebetween, the sustain pulse voltage being provided Are alternately applied to the scan electrode and the sustain electrode, and the sustain pulse voltages for the first sustain electrode and the second sustain electrode, which are the sustain electrodes, have the same phase and different voltage values on the high potential side. Method for controlling a plasma display panel. 3. The plasma display panel drive according to claim 1, wherein the display electrodes are arranged such that the first sustain electrodes or the second sustain electrodes are adjacent to each other between adjacent discharge cells. Method. 3. The method of driving a plasma display panel according to claim 2, wherein the sustain pulse voltage has a positive voltage value on the high potential side and a negative voltage value on the low potential side. 5. The method for driving a plasma display panel according to claim 2, wherein the sustain pulse voltage is switched between the application to the first sustain electrode, which is a sustain electrode, and the application to the second sustain electrode in a predetermined cycle. . 6. The method of driving a plasma display panel according to claim 5, wherein the predetermined period is a period of a sustain pulse voltage.

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