JP5034134B2 - Manufacturing method and manufacturing apparatus for image display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image display device for displaying an image by plasma discharge between the discharge electrodes, e.g., a plasma display panel (PDP) relates to a process for the preparation of, in particular to the aging process, reducing the power during the aging process A method of manufacturing a PDP is provided.
[0002]
[Prior art]
The present invention is used for all image display devices that display an image by plasma discharge between discharge electrodes. Hereinafter, a PDP will be described as an example.
[0003]
Conventional PDPs are generally configured as shown in FIG.
[0004]
This PDP includes a front panel 100 and a back panel 200. In the front panel 100, scan electrodes 102a and sustain electrodes 102b are alternately formed in a stripe pattern on a front glass substrate 101, and further covered with a protective layer 104 made of a dielectric glass layer 103 and magnesium oxide (MgO). It is formed.
[0005]
In the rear panel 200, an address electrode 202 is formed in a stripe shape on a rear glass substrate 201, an electrode protective layer 203 is formed to cover the address electrode 202, and a stripe is formed on the electrode protective layer 203 so as to sandwich the address electrode 202. The barrier ribs 204 are formed in the shape, and the phosphor layer 205 is further provided between the barrier ribs 204. Then, the front panel 100 and the rear panel 200 are bonded together, and a discharge space is formed by enclosing the discharge gas in the space 210 partitioned by the partition wall 204. The phosphor layers are usually arranged in order of phosphor layers of three colors of red, green and blue for color display.
[0006]
In the discharge space 210, for example, a discharge gas obtained by mixing neon and xenon is usually sealed at a pressure of about 0.67 × 10 ⁵ Pa.
[0007]
As described above, in the conventional production of the PDP, after the front substrate and the rear substrate are produced, as an assembly process, bonding / sealing, exhaust / gas filling / sealing are performed to form the PDP . However , a very high voltage is required to display an image on the PDP immediately after the assembly. This is considered because the impurity gas is adsorbed on the surface of the protective film / phosphor. For this reason, after the assembly process, in order to remove the adsorbed impurity gas and stabilize the discharge characteristics of the PDP , an aging process is performed in which the entire discharge region is discharged for a certain period of time.
[0008]
In the aging process, the PDP manufactured as described above is connected to the address driver 220, the scan electrode driver 230, and the sustain electrode driver 240 as shown in FIG. This is performed by alternately applying a voltage to the electrode 102a and the sustain electrode 102b at a predetermined cycle. The driving waveform applied at this time is a continuous rectangular wave driving waveform as shown in FIG. 4 in the conventional aging process , and the voltage value of the rectangular wave is always uniform during the processing period.
[0009]
[Problems to be solved by the invention]
By the way, in this conventional aging process, a long discharge time of about 30 hours is required until the target discharge voltage is stabilized, and a high voltage and a high current value are required to display the entire surface of the PDP. I was trying. For this reason, the power during the aging process becomes enormous, which has been a problem of an increase in running cost when manufacturing the PDP . This kind of problem is the large screen of the PDP, more to become a greater problem as the mass production of the advance is evident.
[0010]
The present invention has been made in view of the above problems, and has been made for the purpose of providing a technique in which power and heat generation during aging processing are reduced.
[0011]
[Means for Solving the Problems]
With respect to the above-described problem, the manufacturing method of the present invention changes the voltage value for the aging process according to the aging process time in the process of aging the image display device that displays an image by plasma discharge between the discharge electrodes. The process of performing the aging process characterized by these. Further, in the aging process, a voltage exceeding the entire lighting voltage of the image display device may be applied, and after a predetermined time, the voltage may be changed to a voltage exceeding the one-point lighting voltage. Further, the voltage value may be lowered 20 to 30 minutes after the start of the aging process, and the frequency to which the voltage is applied may be increased when the voltage value is changed. The voltage value may be decreased every certain period after the start of the aging process. Further, the voltage value may be changed so that the luminance value of the image display device during the aging process is uniform, and in this case, the distribution of the luminance value of the image display device is 10% or less. The voltage value may be changed. The image display device may be a PDP having a scan electrode and a sustain electrode, and may be performed by alternately applying a voltage to the scan electrode and the sustain electrode in a predetermined cycle in the aging process. good. The manufacturing apparatus of the present invention is an apparatus that performs an aging process on an image display apparatus that displays an image by plasma discharge between discharge electrodes, a means for measuring a luminance value of the image display apparatus during the aging process, It is a manufacturing apparatus provided with a means for changing a voltage value for discharging during aging treatment.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, the lighting / extinguishing state during the PDP aging process will be described. At the time of lighting, when the voltage value on the scan electrode side and the sustain electrode side is gradually increased from 0V, first, an image display cell in the PDP plane (hereinafter simply referred to as a cell) is turned on (hereinafter referred to as this cell). The voltage value at that time is a one-point lighting voltage Vf1). As the applied voltage is further increased, the number of lighting cells increases, and finally the entire surface of the PDP is lit (hereinafter, the voltage value at this time is referred to as the entire surface lighting voltage Vfn).
[0013]
On the other hand, when the applied voltage is gradually reduced from the state of full lighting when the light is turned off, the lighting state of the entire PDP becomes uneven and unevenness occurs. Then, a certain cell point in the PDP plane is invalid (hereinafter, the voltage value at this time is referred to as a one-point lighting voltage Ve1). As the applied voltage is further decreased, the number of unlit cells increases, and the entire surface of the PDP is finally turned off (hereinafter, the voltage value at this time is referred to as the full light-off voltage Ven).
[0014]
Here, the magnitude relationship between the four types of voltage values will be described. Generally, the voltage value at which discharge ends is lower than the voltage value required for discharge.
Vf1> Ve1
Vfn> Ven
It becomes.
[0015]
In the conventional aging technique, the set voltage value is set at a value several tens of volts higher than the Vfn. This is because the unevenness of the entire surface of the PDP during aging lighting and aging efficiency are taken into consideration. However, due to this high set voltage value, a large amount of power is conventionally required in the aging process . Therefore, in the present invention, the power during the aging process is reduced by lowering the set voltage after a certain period of time or at a certain period. The voltage value Vs to be reduced is
Vf1>Vs> Ve1
The voltage value satisfying As a result, the inventors succeeded in reducing the power value by about 30% in the implementation of the inventors (in the case of the invention of the first embodiment). Further, as an incidental effect of the present invention, an increase in the surface temperature of the PDP during the aging process can be suppressed, so that the probability of a PDP substrate cracking failure can be reduced. Furthermore, the probability of dielectric breakdown failure can be reduced by lowering the applied voltage.
[0016]
(Embodiment 1)
Next, FIG. 1 shows drive waveforms at the time of aging processing in the first embodiment of the present invention.
[0017]
Conventionally, as shown in FIG. 4, the applied voltage value during the aging process is always constant. In the present invention, a voltage value (Vt) exceeding the full lighting voltage Vfn is applied only during lighting, and after a while, the voltage value is changed to a voltage value ( corresponding to Vs described above ) exceeding the one-point lighting voltage Ve1. At this time, the circuit can be changed by manual change after a certain period of time by using the conventional specification.
[0018]
The time for changing from the voltage Vt to the voltage Vs is changed when there is no luminance unevenness in the PDP plane when the voltage Vt is turned on. In addition, the set voltage Vs is set to the lowest voltage that gradually reduces the applied voltage and does not cause uneven brightness in the PDP plane. This is because the luminance unevenness occurs in the PDP face is for the reasons concerned that unevenness in aging process progress in PDP plane.
[0019]
Regarding this method, there is concern about a decrease in aging efficiency due to a voltage drop , but the inventors investigated the time required for the discharge characteristics to stabilize with respect to the voltage value, so that the applied voltage value has no effect on the aging efficiency. (Here, the aging efficiency is the time until the discharge voltage value is stabilized and the luminance change is saturated, and the high aging efficiency indicates that this time is short). Furthermore, in the PDP by the aging process of the present invention, a result that the number of erroneous discharges and the like is extremely reduced is obtained as compared with the PDP by the conventional aging process .
[0020]
In addition, since the luminance unevenness is almost eliminated after 20 to 30 minutes in the aging process of the conventional PDP, the high voltage period Tt is preferably this time. In the low voltage period Ts, the number of discharges can be increased and the aging efficiency can be increased by shortening the width of the applied pulse, that is, by increasing the frequency of the applied voltage. This is because the applied voltage is lowered. At the same power value as the aging treatment method of the prior art , the number of discharges is increased, the aging efficiency is increased, and the probability of dielectric breakdown failure due to the decrease of the applied voltage. Can also be reduced.
[0021]
(Embodiment 2)
FIG. 2 shows drive waveforms during aging in the second embodiment of the present invention. In the second embodiment, as shown in the figure, a driving waveform and a second rectangular wave as the first rectangular wave and the voltage value Vs to a voltage value Vt, the voltage at every certain period The first rectangular wave having the value Vt and the second rectangular wave having the voltage value Vs are repeated. This is because the display luminance unevenness is removed as compared with the first embodiment by returning the voltage value Vt to a certain period. In the case where T0 is the constant period time, Tt is the time for maintaining the first rectangular wave having the voltage value Vt, and Ts is the time for maintaining the second rectangular wave having the voltage value Vs.
T0 = Tt + Ts
The shorter Tt time is more effective for power reduction, and the first rectangular wave is most preferably one pulse as shown in FIG. According to the study by the inventors, it was good when T0 was 15 to 20 msec (ms). Further, the value of Vs at this time may be a value lower than the single turn-off voltage Ve1. This is because the priming electrons are released into the cell discharge space by the discharge at the applied voltage Vt, the discharge start voltage in the cell is lowered, and the aging discharge is completely generated even at a voltage lower than Ve1. Although the period T0 is constant during the aging process here, there is no problem even if it changes irregularly.
[0022]
(Embodiment 3)
Next, another embodiment is shown below. It has been found that the aging effect is set at the lowest voltage value that does not cause unevenness in the panel brightness of the aging discharge, so that the current aging effect can be obtained and the power can be suppressed. That is, it is effective to monitor the brightness of the panel during the aging process, determine the degree of brightness unevenness from the measured value, and set the optimum voltage value in each case. An example of such an apparatus is shown in FIG. This apparatus is connected to a current aging apparatus, a measuring apparatus for measuring the luminance during the aging process, and a control unit for determining a voltage value based on the luminance value. As the measuring device, a plurality of spot-type luminance measuring devices may be arranged on the surface, or a CCD-type imaging device having the same number or more pixels as the aging display device may be arranged. In addition, since the degree of luminance unevenness at the time of aging is reflected in the luminance unevenness of the normal image, it is desirable to suppress the degree of this luminance distribution to 10% or less. This is because, when the luminance distribution at the time of aging is 10% or more, the luminance distribution value is followed even in video display and becomes a value that can be sufficiently identified even by visual recognition.
[0023]
An example of such an apparatus is shown in FIG. This apparatus is connected to a current aging apparatus, a measuring apparatus for measuring the luminance during the aging process, and a control unit for determining a voltage value based on the luminance value. As the measuring device, a plurality of spot-type luminance measuring devices may be arranged on the surface, or a CCD-type imaging device having the same number or more pixels as the display device that performs aging processing may be considered. In addition, since the degree of luminance unevenness during the aging process is reflected in the luminance unevenness of the normal image, it is desirable to suppress the degree of the luminance distribution to 10% or less. This is because, when the luminance distribution during the aging process is 10% or more, the luminance distribution remains even in video display, and becomes a value that can be identified as a sufficient difference even when visually recognized.
[002 4 ]
【Effect of the invention】
As described above, the present invention is characterized in that the applied voltage value is changed with time in the step of performing an aging process for stabilizing the light emission characteristics of the PDP. In particular, the present invention is characterized in that the applied voltage is lowered, thereby providing a manufacturing method that reduces power during the PDP manufacturing process aging process .
[Brief description of the drawings]
FIG. 1 is a time chart showing a drive waveform in an aging process according to Embodiment 1 of the present invention. FIG. 2 is a time chart showing a drive waveform in an aging process according to Embodiment 2 of the present invention. FIG. 4 is a block diagram showing a connection state between a plasma display panel and a drive circuit. FIG. 4 is a time chart showing drive waveforms in a conventional aging process. FIG. 5 is a partial perspective view showing a conventional plasma display panel. Schematic diagram of aging apparatus according to Embodiment 3 [Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Front panel 200 Back panel 101 Front glass substrate 102a Scan electrode 102b Sustain electrode 103 Dielectric glass layer 104 MgO protective layer 201 Back glass substrate 202 Address electrode 203 Electrode protective layer 204 Partition 205 Phosphor layer 210 Discharge space 220 Address drive part 230 Scan electrode driver 240 Sustain electrode driver 301 Luminance measuring unit 302 Voltage controller 401 High voltage period 402 Low voltage period 403 One cycle period

Claims (8)

In the manufacturing method of an image display device having an aging process of aging an image display device that displays an image by discharging between discharge electrodes,
In the aging process, a rectangular driving waveform is applied,
The drive waveform is composed of a plurality of rectangular waves including a first rectangular wave and a second rectangular wave,
The first rectangular wave and the second rectangular wave have different voltage values,
In the driving waveform, the first rectangular wave and the second rectangular wave are repeatedly applied at regular intervals.   The voltage value of the first rectangular wave is a voltage value Vt exceeding the entire lighting voltage of the image display device, and the voltage value of the second rectangular wave is a voltage value Vs lower than the voltage value Vt. The method for manufacturing an image display device according to claim 1, wherein: The fixed period is T0, the time for applying the first rectangular wave in the fixed period is Tt, and the time for applying the second rectangular wave is Ts,
T0 = Tt + Ts
The method for manufacturing an image display device according to claim 2, wherein T0 is 15 msec to 20 msec.   3. The method of manufacturing an image display device according to claim 2, wherein the first rectangular wave is equivalent to one pulse in the fixed period. In the manufacturing method of an image display device having an aging process of aging an image display device that displays an image by discharging between discharge electrodes,
In the aging process, a plurality of different voltage values are applied,
The different voltage values include a voltage value Vt exceeding the full lighting voltage of the image display device and a voltage value Vs lower than the voltage value Vt,
A method for manufacturing an image display device, wherein a frequency at which the voltage value Vt is applied is different from a frequency at which the voltage value Vs is applied.   6. The method for manufacturing an image display device according to claim 5, wherein the setting time of each of the different voltage values is determined based on a luminance value of the image display device.   The method for manufacturing an image display device according to claim 6, wherein the voltage value is changed when the luminance distribution of the image display device becomes 10% or less.   8. An apparatus for manufacturing an image display apparatus having a mechanism for performing the method for manufacturing the image display apparatus according to 1 to 7.

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