JP4337433B2 - Aging method and aging apparatus for plasma display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an aging method and an aging apparatus for a plasma display panel (PDP).
[0002]
[Prior art]
The plasma display panel is a display device having a large screen, a thin shape, a light weight and excellent visibility. PDP discharge methods include AC and DC types, and electrode structures include a three-electrode surface discharge type and a counter discharge type. However, at present, AC type and three-electrode surface discharge type PDPs are mainly used because they are suitable for high definition and easy to manufacture.
[0003]
An AC type three-electrode surface discharge type PDP has a front substrate on which a plurality of display electrodes made of scan electrodes and sustain electrodes are formed, and a rear substrate on which a plurality of data electrodes are formed in a direction perpendicular to the display electrodes. The discharge space is formed so as to face each other so as to form a discharge space, and a discharge gas composed of neon, xenon, or the like is sealed in the discharge space. A discharge cell is formed at a portion where the display electrode and the data electrode intersect three-dimensionally.
[0004]
In this PDP, a write pulse is applied between a scan electrode and a data electrode, thereby performing a write discharge in a discharge cell to be displayed, and then a period of alternating inversion between the scan electrode and the sustain electrode. By applying a sustain pulse, a sustain discharge is performed in the discharge cell where the address discharge was performed, and this sustain discharge causes the phosphor layer provided in the discharge cell to emit light, thereby displaying a color image. Yes.
[0005]
Here, the minimum driving voltage required for sustaining the sustain discharge is called a complete lighting voltage (Vpd). Generally, the portion of the panel surface having a lower Vpd has a higher luminance, and conversely, the portion having a higher Vpd has a higher luminance. Becomes lower. For this reason, in a panel having a large variation in Vpd in the panel surface, the variation in luminance is also large, which causes a deterioration in display quality.
[0006]
In such a plasma display panel, display electrodes and the like are formed on the front substrate, data electrodes and the like are formed on the rear substrate, and then the front substrate and the rear substrate are disposed so as to form a discharge space therebetween. Then, the periphery is sealed with a low-melting glass frit, and then the discharge gas is sealed in the discharge space.
[0007]
By the way, the panel just assembled generally has a high discharge voltage, the discharge itself is unstable, and the variation in the discharge voltage and the luminance in the panel surface are large. Therefore, for example, as described in Patent Document 1, after completion of the assembly of the panel, a voltage is mainly applied between the scan electrode and the sustain electrode to forcibly discharge over a predetermined time in all the discharge cells. Aging is performed by causing (aging discharge). By this aging, the discharge characteristics in the discharge cells are stabilized, and variations in the discharge voltage and luminance in the panel surface are reduced.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-75208
[Problems to be solved by the invention]
However, when the aging time is short, even if the aging is sufficient in the discharge cell having a low discharge voltage, the aging is insufficient in the discharge cell having a high discharge voltage. On the other hand, when the time for aging is long, even if suitable aging can be performed in a discharge cell having a high discharge voltage, the discharge voltage is excessively lowered due to aging in a discharge cell having a low discharge voltage. As a result, self-erase discharge or the like occurs, and discharge control cannot be performed with a predetermined drive voltage. In addition, the self-erasing discharge causes luminance unevenness (color unevenness) and Vpd to increase, and affects display characteristics and manufacturing yield.
[0010]
In the future, with the increase in the screen size of PDPs and the increase in production volume, it is conceivable that not only variations in discharge characteristics of discharge cells within the panel surface, but also variations in discharge characteristics inherent to each panel will increase with different panels. Therefore, in order to efficiently produce a panel having excellent display characteristics, it is necessary to set an appropriate aging time for each panel and reduce variations in discharge characteristics among discharge cells within the panel surface.
[0011]
The present invention has been made in view of such problems, and by setting an aging time suitable for each panel, the discharge characteristics of the discharge cells in the panel surface are more uniform, and luminance variations are suppressed. The object is to obtain a panel with excellent display characteristics.
[0012]
[Means for Solving the Problems]
In order to achieve such an object, the plasma display panel aging method of the present invention performs aging while detecting the luminance due to the aging discharge at a plurality of positions in the panel surface, and the luminance variation obtained from the detected luminance is obtained. Based on this, the aging end time is controlled.
[0013]
The aging apparatus for a plasma display panel according to the present invention includes an aging voltage generating means for generating a voltage to be applied to the panel, a luminance detecting means for detecting luminance due to aging discharge at a plurality of positions in the panel surface, and the luminance detection. Control means for controlling the aging end time based on the luminance variation obtained from the luminance detected by the means.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
That is, the invention according to claim 1 of the present invention is an aging method for performing aging discharge by applying a predetermined voltage to a plasma display panel, and detecting luminance due to the aging discharge at a plurality of positions in the panel surface. An aging method for a plasma display panel is characterized in that aging is performed while aging is controlled based on luminance variation obtained from detected luminance.
[0015]
The invention according to claim 2 is characterized in that, in the invention according to claim 1, aging is terminated when the luminance variation falls within a predetermined range.
[0016]
The invention described in claim 3 is characterized in that, in the invention described in claim 1, aging is terminated when the luminance variation starts from decreasing to increasing.
[0017]
According to a fourth aspect of the present invention, there is provided an aging device for applying a predetermined voltage to a plasma display panel to perform an aging discharge, an aging voltage generating means for generating a voltage to be applied to the panel, and an aging discharge. The apparatus includes: luminance detecting means for detecting the luminance at a plurality of positions in the panel surface; and control means for controlling the aging end time based on the luminance variation obtained from the luminance detected by the luminance detecting means. An aging device for a plasma display panel.
[0018]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is an exploded perspective view showing the structure of a PDP according to an embodiment of the present invention. In this PDP, generally, a front panel 1 and a rear panel 2 are arranged to face each other, a discharge space is formed between them, the periphery is sealed, and a discharge gas composed of neon, xenon, or the like is sealed in the discharge space. It is configured.
[0020]
The front panel 1 has the following configuration. That is, a plurality of display electrodes 6 including scan electrodes 4 and sustain electrodes 5 are formed in parallel on a front substrate 3 that is a glass substrate, and a dielectric layer is formed on the front substrate 3 so as to cover the display electrodes 6. 7 and a protective layer 8 is formed on the dielectric layer 7.
[0021]
The back panel 2 has the following configuration. That is, a plurality of data electrodes 10 are formed in parallel in a direction orthogonal to the display electrodes 6 on the rear substrate 9 which is a glass substrate, and the base dielectric layer 11 is formed so as to cover the data electrodes 10. . A plurality of barrier ribs 12 parallel to the data electrodes 10 are formed on the base dielectric layer 11, and a phosphor layer 13 is formed on the surface of the base dielectric layer 11 between the barrier ribs 12 and the side surfaces of the barrier ribs 12.
[0022]
FIG. 2 is a schematic view showing an electrode arrangement of the PDP. In the row direction, n scan electrodes SCN _{1 to} SCN _n (scan electrode 4 in FIG. 1) and n sustain electrodes SUS _{1 to} SUS _n (sustain electrode 5 in FIG. 1) are alternately arranged in pairs, M data electrodes D _{1 to} D _m (data electrode 10 in FIG. 1) are arranged in the column direction. A discharge cell is formed at a portion where a pair of scan electrode SCN _i and sustain electrode SUS _i (i = 1 to n) and one data electrode D _j (j = 1 to m) are three-dimensionally crossed, and the discharge cell M × n are formed in the discharge space.
[0023]
In this PDP, one field period of a video signal is divided into a plurality of subfields having luminance weights, and discharge for display is caused in the discharge cells by the number of times corresponding to the luminance weighting in each subfield. A driving method for expressing the gradation of a video signal by combining subfields that cause discharge is used.
[0024]
FIG. 3 shows an example of a drive waveform in one subfield, which is composed of four operation periods of an initialization period, a write period, a sustain period, and an erase period. In the initialization period, in all the discharge cells, initialization charges (a predetermined amount of wall charges required for the write operation) are formed between the scan electrodes SCN _i and the data electrodes D _j and priming particles are generated. Perform initializing discharge. In the address period, address discharge is performed between the scan electrode SCN _i and the data electrode D _j and further between the scan electrode SCN _i and the sustain electrode SUS _i in the discharge cell to be displayed. In the sustain period, the sustain discharge is repeatedly performed between the scan electrode SCN _i and the sustain electrode SUS _i in the discharge cell in which the address discharge is performed. The number of sustain discharges is set in accordance with the weighting of the luminance of the subfield, and the phosphor layer emits light by this sustain discharge, thereby displaying an image. In the erasing period, erasing discharge is performed between the scanning electrode SCN _i and the sustaining electrode SUS _i to erase wall charges generated by the sustaining discharge.
[0025]
FIG. 4 is a block diagram showing the configuration of the PDP aging apparatus according to the embodiment of the present invention. The aging device detects the brightness of the light emission associated with the aging discharge of the panel 14, the panel mounting table 15 for mounting the panel 14 to be aged, the aging voltage generating means 16 for generating the aging voltage supplied to the panel 14. And a control means 18 for controlling the aging voltage generation means 16 on the basis of the luminance characteristics (time dependency) detected by the brightness detection means 17.
[0026]
All the scanning electrodes SCN ₁ ~SCN _n and all the sustain electrodes SUS ₁ ~SUS _n of the panel 14 is electrically common with each conductive plate (not shown), all the scanning electrodes SCN ₁ ~SCN _n is connected to the scan electrode output terminal 20 of the aging voltage generating means 16 using the cable 19, and all the sustain electrodes SUS _{1 to} SUS _n are connected to the sustain electrode output terminal 21 of the aging voltage generating means 16 using the cable 19. It is connected to the. Then, the aging voltage generation means 16 alternately applies a pulse voltage to the scan electrodes SCN _{1 to} SCN _n and the sustain electrodes SUS _{1 to} SUS _n. The magnitude of the pulse voltage at this time is a normal image display. When performing, it is set to a value larger than the magnitude of the pulse voltage applied to scan electrodes SCN _{1 to} SCN _n and sustain electrodes SUS _{1 to} SUS _n . Incidentally, the data electrodes D ₁ to D _m of the panel 14 may be carried out aging in an open state, but grounded or data electrodes D ₁ to D _m as required, or the data electrodes D ₁ to D _m Aging may be performed while applying a predetermined voltage waveform.
[0027]
The luminance detection means 17 is configured using, for example, a non-contact type spectral radiance meter, and converts the luminance of light emission accompanying discharge into an electric signal. The spectral radiance meter may be a contact type that is used in contact with the surface of the panel 14. The control means 18 analyzes the brightness of the panel 14 during aging, and controls the time for aging according to the analysis result. The control means 18 may be configured by a dedicated circuit, You may comprise using a general purpose personal computer.
[0028]
Next, a method for performing PDP aging using the aging apparatus shown in FIG. 4 will be described.
[0029]
The scanning electrodes SCN ₁ ~SCN _n and sustain electrodes SUS ₁ ~SUS _n of the panel 14, performs aging by applying the respective aging voltage generating means 16 a pulse waveform alternately face of the panel 14 by the luminance detection means 17 The brightness at each position is detected at a plurality of positions, and the brightness variation in the plane of the panel 14 is obtained from the detected brightness. When detecting the luminance at each position in the surface of the panel 14, the luminance may be detected while scanning one or a plurality of luminance detecting means 17 within the display area of the panel 14 at a constant speed. Further, a plurality of positions for detecting the luminance may be determined in the plane of the panel 14, and the luminance detecting means 17 may be arranged and fixed corresponding to each position to detect the luminance at each position. .
[0030]
FIG. 5 shows an example of a change with respect to time (aging time) of luminance at a predetermined position in the plane of the panel 14 when aging is performed. Here, the position where the luminance is detected is determined as follows. That is, before performing aging, the panel 14 is turned on to measure the luminance distribution in the display area. As a result, the position A where the luminance is the maximum value, the position B where the luminance is the minimum value, and the luminance are intermediate. A value position C was detected. The luminance during aging is detected at each of these positions. In FIG. 5, changes in luminance at time positions A, B, and C determined in this way are shown by curves A, B, and C, respectively.
[0031]
In addition, FIG. 6 shows the results of measuring the luminance by applying a driving voltage when performing normal image display (during actual driving) by temporarily stopping aging at every predetermined aging time during aging. Shown in In FIG. 6, a curve A, a curve B, and a curve C represent changes in luminance at the positions A, B, and C, respectively. As shown in FIG. 6, it can be seen that the luminance at each position shows the same change as the change in luminance accompanying the aging discharge during aging shown in FIG. Therefore, the luminance variation obtained by detecting the luminance due to the aging discharge at the time of aging reflects the luminance variation when the driving voltage at the actual driving is applied.
[0032]
As shown in FIG. 5, the in-plane luminance variation is the largest at the start of aging. Here, the luminance variation is the difference between the maximum value and the minimum value of the luminance. As the aging is performed, the luminance at each position increases, and at the same time, the luminance variation decreases. Here, it is considered that the brightness increases due to aging because the discharge voltage and discharge area (discharge spread) in each discharge cell increase because the discharge voltage in each discharge cell decreases due to aging. In addition, the variation in luminance is reduced because the amount of change in discharge voltage due to aging differs depending on the position.In the position where the discharge voltage was originally low, the amount of decrease in discharge voltage due to aging was small, and in the position where the discharge voltage was originally high. This is thought to be because the amount of decrease in discharge voltage due to aging is large. The reason why the amount of change in the discharge voltage due to aging varies depending on the position in the panel surface is considered to be the effect of the amount and type of impure gas adsorbed on the protective layer 8 when the panel assembly is completed.
[0033]
As the aging time becomes longer, the position A tends to decrease in luminance at a certain aging time, and if the aging is continued thereafter, the luminance difference between the position B and the position C increases. The cause is considered to be that the discharge voltage at the position A is excessively lowered by performing aging for a long time, and self-erasing discharge is easily generated. The self-erasing discharge is a discharge in which wall charges formed by the discharge are erased by a weak discharge generated when the applied voltage falls, and is likely to occur when an excessively high voltage is applied to the discharge characteristics of the discharge cell. Generally, the PDP controls the discharge by the superimposed voltage of the applied voltage and the wall voltage generated by the wall charge. Therefore, when the self-erasing discharge occurs, the wall voltage decreases, and as a result, the above-described complete lighting is achieved. The voltage (Vpd) will rise. Therefore, when self-erasing discharge occurs, the luminance at that position decreases.
[0034]
FIG. 7 shows changes in luminance variation obtained from the luminance detection results shown in FIG. 5, where the horizontal axis represents time (aging time) and the vertical axis represents luminance variation. As shown in FIG. 7, the luminance variation is greatest at the start of aging, decreases as aging is performed, becomes minimum at a certain time t ₁ , and increases again after the time t ₁ is exceeded.
[0035]
In the present embodiment, control is performed so that aging is terminated when time t ₁ shown in FIG. 7 is exceeded. That is, the aging voltage generating means 16 is controlled by the control means 18 so that the aging is terminated when the luminance variation starts from decreasing to increasing. It should be noted that aging is terminated when the magnitude of the luminance variation (B _d ) is, for example, 10% or less (B _d / B _ave ≦ 0.1) with respect to the average value (B _ave ) of the luminance in the panel surface. You may set conditions. That is, aging may be terminated when the luminance variation is within a predetermined range.
[0036]
In this way, the conditions for ending aging can be set as appropriate according to panel productivity and panel quality, and the aging end time is controlled based on the luminance variation obtained from the luminance detected during aging. Thus, an aging time suitable for each panel can be set. As a result, aging can be completed with the discharge voltage variation and brightness variation more uniform in the panel surface. As a result, a panel with excellent display characteristics can be produced with high yield, and the aging time is reduced and the aging power is reduced. Can be reduced.
[0037]
【The invention's effect】
As described above, according to the present invention, the discharge characteristics of the discharge cells in the panel surface are more uniform, the luminance variation is suppressed, and a panel with excellent display characteristics can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a structure of a plasma display panel according to an embodiment of the present invention. FIG. 2 is a schematic view showing an electrode arrangement of the plasma display panel. FIG. 4 is a configuration diagram of an aging device according to an embodiment of the present invention. FIG. 5 is a characteristic diagram showing a temporal change in luminance at a predetermined position in the panel surface when aging is performed by the aging device. FIG. 6 is a characteristic diagram showing temporal changes in luminance when aging is temporarily stopped and actual driving is performed during aging. FIG. 7 shows temporal variations in luminance when aging is performed by the aging device. Characteristic diagram showing changes 【Explanation of symbols】
14 Panel 16 Aging voltage generating means 17 Luminance detecting means 18 Control means

Claims (4)

An aging method in which a predetermined voltage is applied to a plasma display panel to perform aging discharge, wherein aging is performed while detecting the luminance due to the aging discharge at a plurality of positions in the panel surface, and luminance variation obtained from the detected luminance An aging method for a plasma display panel, wherein the aging end time is controlled based on the method. 2. The method of aging a plasma display panel according to claim 1, wherein the aging is terminated when the luminance variation falls within a predetermined range. 2. The method of aging a plasma display panel according to claim 1, wherein the aging is terminated when the luminance variation starts from decreasing to increasing. An aging device for applying a predetermined voltage to a plasma display panel to perform an aging discharge, an aging voltage generating means for generating a voltage to be applied to the panel, and detecting brightness due to the aging discharge at a plurality of positions in the panel surface An aging apparatus for a plasma display panel, comprising: luminance detection means; and control means for controlling an aging end time based on a luminance variation obtained from the luminance detected by the luminance detection means.

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