JP2002093379A - Discharge formation device, discharge luminous device, plasma display panel and illumination device and display device using these - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge luminous device and a plasma display panel and its display device that have a high luminous efficiency and are capable of giving stable discharge. SOLUTION: In the discharge luminous device and the plasma display panel and its display device, discharge is made to be concentrated by the configuration of the first electrode 1, and the voltage is reduced at the timing when the discharge current is to be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge forming device by gas discharge, a discharge light emitting device, a plasma display panel, and an illuminating device and a display device using the same.

[0002]

2. Description of the Related Art Liquid crystal panels are widely used in various display devices such as personal computer monitors and televisions because of their thinness, lightness, and low power consumption. However, since the liquid crystal itself is not a self-luminous element, display requires a backlight for supplying light from the back of the liquid crystal panel. As the backlight, an edge light system in which a thin tube cold cathode fluorescent lamp is installed at an end of a light guide plate is generally used, but a direct type using a flat discharge lamp is also used.

FIG. 16 shows a conceptual diagram of a typical flat discharge lamp. FIG. 3A is a plan view, and FIGS. 3B and 3C are cross-sectional views. The discharge space is composed of two glass substrates and spacers. Two electrodes covered with a dielectric are formed inside the front glass, and a phosphor is applied inside the rear glass. The discharge space is filled with mercury and rare gas,
Ultraviolet rays are generated by the gas discharge, and the phosphors are excited by the ultraviolet rays to emit light.

A method of driving a flat discharge lamp is to alternately apply rectangular voltage waveforms to two electrodes on a front panel, and by appropriately selecting the period and pulse width of the rectangular waves, the entire discharge space can be driven. The aim is to obtain light emission that spreads uniformly.

[0005] However, the conventional flat discharge lamps still have problems in that the luminous efficiency is low, the discharge starting voltage is high, and the luminance is low. It is also difficult to spread light emission uniformly over the entire discharge space. This is probably because the positive column was not used stably.

Various studies have been made on the above-mentioned problems, and patents include, for example, Japanese Patent Application Laid-Open No. 9-27
298, JP-A-10-22203, JP-A-11-7916, JP-A-11-144678, and the like, but sufficient results have not been obtained even if the above patent information is adopted.

On the other hand, a plasma display panel (PD)
P) is a flat panel display technology because it can display at a higher speed, has a wider viewing angle, is easier to increase in size, and has higher display quality because it is a self-luminous type, as compared to liquid crystal panels. In recent years, it has attracted particular attention.

[0008] In general, in a PDP, ultraviolet light is generated by gas discharge, and a fluorescent material is excited by the ultraviolet light to emit light, thereby performing color display. Then, a display cell partitioned by a partition is provided on the substrate, and a phosphor layer is formed on the display cell. In particular, the current mainstream of PDPs is a surface discharge type PDP having a three-electrode structure, which has a pair of display electrodes adjacent in parallel on one substrate and a direction intersecting the display electrodes on the other substrate. The address electrode 23, the partition 16 and the phosphor layer 17 can be relatively thick, and it can be said that the phosphor layer is suitable for color display using the phosphor. FIG. 17 is a partially exploded perspective view (conceptual diagram) of a typical surface discharge type PDP having a three-electrode structure. The display electrode pair is composed of a scan electrode (scan electrode) 21 and a sustain electrode (sustain electrode) 22.

A conventional panel driving method divides one field period into a plurality of subfields having a weight of a light emitting period based on a binary system, and performs gradation display by a combination of subfields to emit light. It is. Each subfield includes an initialization period, an address period, and a sustain period. In order to display image data, different signal waveforms are applied to each electrode during the initialization period, the address period, and the sustain period. In the initialization period, an initialization pulse is applied to all scan electrodes 21. In the address period, by applying a write pulse between the address electrode 23 and the scan electrode 21, an address discharge is performed between the address electrode 23 and the scan electrode 21 to select a discharge cell. In the subsequent sustain period, a sustain discharge is applied between the scan electrode 21 and the sustain electrode 22 for a certain period to alternately invert the periodic sustain pulse, thereby causing a sustain discharge between the scan electrode 21 and the sustain electrode 22. And display.

[0010] However, the conventional plasma display apparatus still has a problem in that the luminous efficiency is low and the luminance is low. For example, the luminous efficiency is 1 lm / W, which is about 1/5 of a CRT.

Although various studies have been made on the above problems, there has been no example in which a PDP using a positive column for increasing the luminous efficiency of ultraviolet rays has been put to practical use. This is because the size of the PDP cell is limited with respect to the distance between the electrodes required for the positive column, and it is difficult to control the discharge by simply increasing the distance between the electrodes, which makes the discharge unstable and difficult. It is thought that it is possible.

As a patent, for example, Japanese Patent Application Laid-Open No. Hei 5-4116
No. 5, JP-A-5-41164, JP-A-6-2
No. 75202, etc., but sufficient results have not been obtained even if the above patent information is adopted.

[0013]

As described above, the conventional flat discharge lamps have the problems that the luminous efficiency is low, the discharge starting voltage is high, and the luminance is low.

A first object of the present invention is to solve the above-mentioned problems, that is, to make it possible to use a positive column stably, to achieve high brightness,
It is an object of the present invention to provide a discharge light emitting device realizing high luminous efficiency, a driving method thereof, and a lighting device and a display device using the same.

On the other hand, as described above, the conventional plasma display device has a problem that the luminous efficiency is significantly lower than that of a display device such as a CRT. In general, a positive column can be generated by increasing the distance between the electrodes that cause a discharge. However, in a PDP cell configuration, simply increasing the distance between the electrodes does not stabilize the positive column, and the discharge flickers.
The luminous efficiency is not so large.

A second object of the present invention is to solve the above-mentioned problems, that is, it is possible to use a positive column stably, to obtain high brightness,
It is an object of the present invention to provide a driving method of a plasma display panel realizing high luminous efficiency and a display device using the same.

[0017]

According to the present invention, a discharge forming device, a discharge light emitting device, a plasma display panel and a driving method thereof, and a lighting device and a display device using the same are provided with a means for concentrating discharge,
It is characterized by having means for suppressing a discharge current caused by the discharge.

In general, gas discharge tends to concentrate when a rare gas is used, so that a uniform discharge cannot be obtained once the discharge is concentrated, and the discharge current becomes excessive when the discharge is concentrated once. Since the flow and local brightness become high but the efficiency drops considerably, it has been a point of development how to expand the discharge and achieve high efficiency. Further, spreading the positive column over the entire space can be realized solely by the pulse width and timing of the applied voltage, but generally these drive margins are narrow and difficult to control. This tendency was more pronounced at higher gas pressures, making it difficult to use these gas pressure regions with high efficiency.

On the other hand, in the present invention, high brightness is realized by intentionally concentrating discharge, and high efficiency is simultaneously realized by suppressing excessive discharge current. As a result, a large margin for the driving conditions can be obtained, so that control can be easily performed, and a region having a high gas pressure can be used, so that the efficiency can be further increased.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a discharge forming device having means for concentrating gas discharge and means for suppressing a discharge current caused by the gas discharge.

With such a discharge forming device, it is possible to obtain a very strong discharge by concentrating the discharge, and it is possible to obtain a high-efficiency discharge by suppressing a discharge current, thereby saving unnecessary power.

According to a second aspect of the present invention, there is provided a discharge light emitting device having a means for concentrating a gas discharge and a means for suppressing a discharge current caused by the gas discharge.

With such a discharge light emitting device, a very strong discharge can be obtained by concentrating the discharge, and a high efficiency discharge can be obtained by suppressing a discharge current, thereby saving unnecessary power. Brightness and high luminous efficiency can be realized.

According to a third aspect of the present invention, the gas discharge is formed by applying a voltage between the electrodes, and a means for concentrating the gas discharge is realized by the shape of the electrode. Is a discharge light emitting device.

With such a discharge light emitting device, for example, by providing a projection in the shape of an electrode, the lines of electric force are concentrated on the projection and the electric field intensity is increased, so that the discharge can be easily concentrated.

According to a fourth aspect of the present invention, the gas discharge is formed by applying a voltage between the electrodes, and the gas discharge is formed by the shape of the dielectric film formed directly or indirectly on the electrodes. 3. The discharge light emitting device according to claim 2, wherein means for concentrating is realized.

With such a discharge light emitting device, for example, if a dielectric film made of a material having a high secondary electron emission coefficient is formed on an electrode and a discharge is generated only in a part of the electrode, the discharge is concentrated as a result. It is possible to do.

According to a fifth aspect of the present invention, a gas discharge is formed by applying a voltage between electrodes, and a discharge current is suppressed by connecting an inductance in series to at least one of the electrodes. 5. The discharge light emitting device according to claim 2, wherein the means is realized.

With such a discharge light emitting device, a discharge current flowing excessively can be controlled by the back electromotive force of the inductance. Once the discharge is concentrated, the discharge current tends to flow at once, and if the back electromotive force can be generated in a self-adjusting manner by the inductance, not only the discharge current can be suppressed, but also the fluctuation can be suppressed. Very stable discharge results.

According to a sixth aspect of the present invention, a gas discharge is formed by applying a voltage between the electrodes, and the discharge current is suppressed by decreasing the voltage at a timing at which the discharge current is suppressed. 5. The discharge light emitting device according to claim 2, wherein the means is realized.

With such a discharge light emitting device, it is possible to control a discharge current flowing excessively by forcibly applying a back electromotive force.

The invention according to claim 7 of the present invention is the discharge light emitting device according to any one of claims 2 to 6, wherein a plurality of concentrated discharges are formed by means for concentrating gas discharge.

With such a discharge light emitting device, it becomes possible to form a plurality of discharges localized by concentration two-dimensionally to obtain light emission of surface discharge.

An eighth aspect of the present invention is the discharge light emitting device according to the seventh aspect, wherein a plurality of concentrated discharges are separated by partition walls.

With such a discharge light emitting device, it is possible to form a wall in the vicinity of the concentrated discharge and to easily control the positive column. This is because the conditions for generating the positive column discharge are greatly affected by the wall. Further, by forming a phosphor on the wall, light emission can be obtained in the vicinity of discharge, and higher-luminance light emission can be realized.

According to the ninth aspect of the present invention, light is emitted by a concentrated discharge by means for concentrating a gas discharge,
9. The discharge light emitting device according to claim 2, further comprising means for diffusing the light emission.

With such a discharge light emitting device, a wide range of light emission can be realized by spreading the discharge localized by concentration. In addition, it is possible to make the surface light emission obtained by forming a plurality of discharges localized by concentration two-dimensionally more uniform.

According to a tenth aspect of the present invention, there is provided an illumination apparatus configured to illuminate an illuminated object using the discharge light emitting device according to any one of the second to ninth aspects.

With such an illuminating device, it is possible to obtain a very strong discharge by concentrating the discharge, and by suppressing the discharge current, it is possible to save wasteful power and obtain a high-efficiency discharge. Thus, a backlight with high luminous efficiency can be realized.

An eleventh aspect of the present invention is a display device using the discharge light emitting device according to any one of the second to ninth aspects, or a lighting device according to the tenth aspect.

With such a display device, it is possible to obtain a very strong discharge by concentrating the discharge, and it is possible to obtain a high-efficiency discharge by suppressing the discharge current, thereby saving unnecessary power. Thus, a display with high luminous efficiency can be realized.

According to a twelfth aspect of the present invention, there is provided a plasma display panel capable of displaying an image by controlling light emission by gas discharge for each pixel, wherein the means for concentrating the discharge and the discharge are provided. And a means for suppressing a discharge current caused by the plasma display panel.

With such a plasma display panel, it is possible to obtain a very strong discharge by concentrating the discharge, and it is possible to obtain a highly efficient discharge by suppressing the discharge current, thereby saving unnecessary power. Brightness and high luminous efficiency can be realized.

According to a thirteenth aspect of the present invention, the gas discharge is formed by applying a voltage between the electrodes, and a means for concentrating the discharge is realized by the shape of the electrodes. It is a display panel.

With such a plasma display panel, for example, by providing projections in the shape of electrodes, the lines of electric force are concentrated on the projections and the electric field strength is increased, so that the discharge can be easily concentrated.

According to a fourteenth aspect of the present invention, the gas discharge is formed by applying a voltage between the electrodes, and the discharge is performed by the shape of the dielectric film formed directly or indirectly on the electrodes. 13. The plasma display panel according to claim 12, wherein means for concentrating is realized.

With such a plasma display panel, for example, if a dielectric film made of a material having a high secondary electron emission coefficient is formed on an electrode and a discharge is generated only in a part of the electrode, the discharge is concentrated as a result. It is possible to do.

According to a fifteenth aspect of the present invention, a gas discharge is formed by applying a voltage between electrodes, and a discharge current is suppressed by connecting an inductance in series to at least one of the electrodes. 15. The plasma display panel according to claim 12, wherein the means is realized.

With such a plasma display panel, an excessive discharge current can be controlled by the back electromotive force of the inductance. Once the discharge is concentrated, the discharge current tends to flow at once. If the discharge can be controlled in a self-adjusting manner by the inductance, not only the discharge current can be suppressed but also its fluctuation can be suppressed, resulting in a very stable discharge. Becomes

According to a sixteenth aspect of the present invention, the gas discharge is formed by applying a voltage between the electrodes, and the discharge current is suppressed by decreasing the voltage at a timing at which the discharge current is suppressed. 15. The plasma display panel according to claim 12, wherein the means is realized.

With such a discharge light emitting device, it is possible to control a discharge current flowing excessively by forcibly applying a back electromotive force.

The invention according to claim 17 of the present invention is a display device using the plasma display panel according to any one of claims 12 to 16.

With such a display device, it is possible to obtain a very strong discharge by concentrating the discharge, and it is possible to obtain a high-efficiency discharge by suppressing the discharge current, thereby saving unnecessary power. Thus, a display with high luminous efficiency can be realized.

By providing the "means for concentrating discharge" according to the present invention, if the formed discharge has increased spatial non-uniformity as compared with the case where the discharge is not provided, the present invention will be described. It is understood that this corresponds to "concentrating discharge".

In addition, by providing the “means for suppressing the discharge current” according to the present invention, if the discharge current is reduced as compared with the case where the discharge current is not provided, the “means for suppressing the discharge current” is described. I understand that it is true.

Hereinafter, the present invention will be described in detail with reference to embodiments, but embodiments of the present invention are not limited thereto.

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The discharge forming device described in the present embodiment is characterized in that it has means for concentrating discharge and means for suppressing discharge current caused by the discharge.

The discharge light emitting device, the driving method, the illuminating device and the display device described in the present embodiment are characterized by having means for concentrating discharge and means for suppressing a discharge current caused by the discharge. The gas discharge is formed by applying a voltage between the electrodes,
The means for concentrating the discharge is realized by the shape of the electrode.

Also, the gas discharge is formed by applying a voltage between the electrodes, and means for suppressing the discharge current is realized by connecting an inductance in series to at least one of the electrodes. Features.

Further, by the above-mentioned mechanism or / and means,
A plurality of concentrated discharges are formed.

Hereinafter, the present embodiment will be described with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[Device Structure] FIG. 1 shows a conceptual diagram of the discharge light emitting device used in the first embodiment. (A) is a plan view, and (b) and (c) are cross-sectional views. The discharge light emitting device shown in FIG. 1 has two types of electrodes substantially parallel to each other on the inner surface of one first substrate 11 of a pair of substrates sandwiching a discharge space, a first electrode 1,
A reflective layer 16 having a second electrode 2, a dielectric layer 13, and a protective film 14, and reflecting visible light on the inner surface of the other second substrate 12,
And a phosphor 17 that emits light by discharge. 1st electrode
The distance between the first and second electrodes 2 can form a positive column discharge.
2 mm or more.

The material of the substrate is generally soda lime glass, but is not particularly limited. The electrodes are generally formed of silver or chromium / copper / chromium (laminated structure), but are not particularly limited. The phosphor is not particularly limited as long as it is excited by ultraviolet rays generated by the discharge and emits light. As the material of the dielectric, low melting glass is generally used, but is not particularly limited. The protective film is preferably made of a material having a high secondary electron emission coefficient γ, and is generally MgO, but is not particularly limited. The discharge gas is generally a mixed gas of at least one of He, Ne, and Ar and Xe or Xe gas, but is not particularly limited. Mercury may be used if necessary. The structure of the device is not necessarily required to be flat, but may be a thin tube. The electrodes do not necessarily need to be covered with a dielectric layer or a protective film. Also, the first electrode 1 and the second electrode 2 need not necessarily be formed on the inner surface of the same substrate. Also, the form of the discharge does not necessarily have to be a positive column, and therefore the distance between the first electrode 1 and the second electrode 2 is arbitrary. However, the luminous efficiency is greatly improved by the positive column discharge, and the present invention is particularly effective when the positive column discharge is used.

A mechanism for concentrating the discharge will be described below. In the present embodiment, the mechanism for concentrating the discharge is realized by the shape of the electrode. In the example of FIG. 1, a projection is formed on a part of the electrode, and when a voltage is applied between the electrodes, the lines of electric force are concentrated and the electric field strength is increased. The shape of the protruding portion may be selected from an optimum shape based on the balance between the degree of concentration of discharge and the degree of suppression of discharge current described later. If the discharge can be concentrated, the projection is not necessarily required. For example, the discharge can be concentrated by reducing the distance between the electrodes only in a certain region of the electrodes.

Here, the mechanism for concentrating the discharge need not necessarily be formed on both the first electrode 1 and the second electrode 2. For example, if a projection is provided on the first electrode 1 in a certain discharge area and the second electrode 2 is formed in a linear shape, the discharge is concentrated on the first electrode 1 side, and in this area, a triangular discharge shape is obtained. If 2 is an arc shape, it will be a fan-shaped discharge shape. When a plurality of these are formed, a projection may be provided only on the first electrode 1 in one region, and a projection may be provided only on the second electrode 2 in another region. Also, it is not always necessary to form a plurality. The roles of the two types of electrodes do not necessarily need to be different, and may be completely equivalent.

That is, the polarity of the voltage applied to each electrode may be fixed, or may be alternately switched. The electrode pairs formed by these electrodes may have a repeating structure as shown in FIG. By employing such a repetitive structure, the light emitting area can be freely set. The same applies to the case where the same type of adjacent electrodes in FIG.

Next, the means for suppressing the discharge current will be described. In the present embodiment, the mechanism or means for suppressing the discharge current is realized by connecting an inductance in series to at least one of the electrodes. At this time, it is not always necessary to generate a back electromotive force (for example, an inductance) as long as it has the effect of suppressing the discharge current.

These effects will be described below using an example of driving by a driving method. Next, the effect of forming a plurality of concentrated discharges by the above-described mechanism or / and means will be described. First, surface discharge light emission can be obtained by forming a plurality of concentrated discharges two-dimensionally. Furthermore, since concentrated discharges have a very strong light emission intensity locally, even if they are diffused and made two-dimensionally uniform, they can be obtained by two-dimensionally uniform discharge from the beginning and have higher brightness than light emission. Become.

Furthermore, while a two-dimensionally uniform discharge causes a current to flow over the entire surface, forming a plurality of concentrated discharges locally causes a current to flow. It does not always grow. Therefore, high luminance and high luminous efficiency can be realized by optimization.

As means for obtaining two-dimensionally uniform light emission by concentrated discharge, for example, when a concentrated discharge is used as a light source and this arrangement is designed, a region which is not a light source is made to reduce leakage light from a plurality of surrounding light sources. What is necessary is just to arrange | position so that uniform light emission may be obtained as a whole by superimposing.
Further, the arrangement of the phosphors may be devised so that the light emission becomes uniform.

The formation of a plurality of concentrated discharges can be applied not only two-dimensionally but also three-dimensionally.

[Driving Method] FIG. 3 shows that the first electrode 1
3 shows a voltage waveform applied to the second electrode 2. FIG. 2A shows a voltage waveform applied to the first electrode 1 and FIG. 2B shows a voltage waveform applied to the second electrode 2. In FIG. 3, the voltage of the second electrode 2 changes from Hi to Lo, and the voltage of the first electrode 1 changes to Lo.
Only the period during which the state changes from Hi to Hi is shown. This voltage waveform is an output waveform from the circuit, and the voltage waveform actually applied to the electrodes changes due to the inductance described later.

In the discharge period, the voltage of the second electrode 2 changes from Hi to L
o, the period when the voltage of the first electrode 1 changes from Lo to Hi, the voltage of the first electrode 1 changes from Hi to Lo, and the voltage of the second electrode 2 changes from Lo
Light is emitted continuously by repeating the period of changing to Hi. However, it is not necessary to repeatedly invert the applied voltage unless the electrode is covered with the dielectric layer. The voltage waveform does not necessarily have to be a rectangular wave, but may be a sine wave or the like. It is generally advantageous that the rising speed of the applied voltage is small because the discharge is easily concentrated. Alternatively, a voltage may be applied such that one of the electrodes is always Hi. In this case, it is desirable that the wall charges be erased to some extent within one cycle by self-erasing discharge or the like.

First, during the period when the voltage of the second electrode 2 changes from Hi to Lo, the potential difference between the first electrode 1 and the second electrode 2 is reduced, and the capacitor of the device is discharged. At this time, a self-erasing discharge can be generated, and a subsequent discharge can be generated using the self-erasing discharge as a trigger.

Subsequently, during a period in which the voltage of the first electrode 1 changes from Lo to Hi, a potential difference is generated between the first electrode 1 and the second electrode 2 to make the first electrode 1 positive and the second electrode Charge the device with 2 negative.

Next, when the electric field intensity between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge starts. Here, by designing the projections of the electrodes so that the lines of electric force concentrate and the electric field strength is increased, discharge can be started at these projections. As a result, the discharge concentrates on the protruding portion without spreading over the entire area between the electrodes.

When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet light generated by the discharge excites the phosphor to emit light. At this time, the discharge current starts to flow at once, but a counter electromotive force is generated by the inductance connected in series to at least one of the electrodes, and the discharge current is suppressed. At this time, it is not always necessary to generate a back electromotive force (for example, an inductance) as long as it has the effect of suppressing the discharge current. Further, the inductance may be connected at a timing for suppressing an increase in the discharge current, or may be connected in advance. Since the optimum value of the inductance varies depending on the capacity of the device, the inductance may be selected in accordance with the capacity of the device so as to appropriately suppress the discharge current.

When actually observing the discharge current, it can be seen that the discharge current becomes small and has a gentle current waveform. This is because the inductance generates back electromotive force in a self-adjusting manner due to a change in the discharge current, and thus suppresses not only the discharge current but also the fluctuation of the discharge current. At this time, observing the positive column shows that it is very strong and stable.

By driving in this manner, a luminance of 8000 cd / m ² and a luminous efficiency of 30 lm / W could be obtained without using mercury.

Next, a case where no projection is provided on the electrode will be described. When no projection is provided on the electrode, the discharge can be spread over the entire surface by selecting the optimum conditions. Optimum conditions can be found by exclusively examining the conditions of pulse width and timing of applied voltage.
Generally, it is a reality that the drive margin is narrow and difficult to control. If the optimization is not performed, the discharge concentrates. However, since the discharge concentrated in this way is not controlled at all, it moves spatially with time and becomes unstable. Therefore, when no projection is provided on the electrode, the most appropriate driving method is to drive by spreading the discharge over the entire surface. However, in such a driving method in which the discharge is spread over the entire surface, the discharge current is small, but the luminance is low and the operation margin is narrow. Therefore, if the driving voltage is increased to increase the luminance, the discharge is concentrated and the control is difficult. When the Xe partial pressure is increased, the luminous efficiency is increased, but the operation margin is further narrowed, which is not practical. In the case where no protruding portion was provided on the electrode, a luminance of 5000 cd / m ² and a luminous efficiency of 15 lm / W were obtained in a similar experiment.

Next, the case where the inductance is not connected, the size of the connected inductance does not match the capacity of the device, or the case where the inductance is connected at an inappropriate timing will be described. In such a case, it can be seen that the current flows at once when the discharge starts. Although the discharge is concentrated and localized, the discharge current over the entire surface is greater than when the discharge is spreading. As described above, as the discharge current increases, the ratio of contribution to light emission decreases, so that the light emission efficiency extremely decreases. Actually, when the discharge current was not suppressed in this way, 8000 cd
/ m ² of brightness, to obtain a luminous efficiency of 5 lm / W.

From these results, means for concentrating discharge,
In addition, it can be seen that the provision of the means for suppressing the discharge current caused by the discharge makes it possible to realize a discharge light emitting device or the like with high luminance and high luminous efficiency. In addition, the process of providing a potential difference between the electrodes does not necessarily need to be performed by charging the device, and may use, for example, device discharge (not gas discharge). That is, the first electrode 1,
It is also possible to change the second electrode 2 from the Hi, Hi state to the Lo, Hi state.

In the example shown in FIG. 1, if a phosphor is not used or the phosphor is separated, a discharge forming device is obtained.

A lighting device can be realized by combining a circuit for realizing the above driving method with the above panel.

A display device can be realized by combining the above-mentioned lighting device with, for example, a liquid crystal and a liquid crystal driving circuit.

(Embodiment 2) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The discharge light emitting device, the driving method, the illuminating device, and the display device described in the present embodiment are characterized by having means for concentrating discharge and means for suppressing discharge current caused by the discharge. The gas discharge is formed by applying a voltage between the electrodes,
The means for concentrating the discharge is realized by the shape of the dielectric film formed directly or indirectly on the electrode.

Hereinafter, the present embodiment will be described with reference to specific examples, but the embodiments of the present invention are not limited thereto.

The discharge light emitting device of the second embodiment is basically the same as that of the first embodiment, but differs in a mechanism for concentrating discharge. Hereinafter, only different portions will be described. The driving method, the lighting device, and the display device are the same as those in the first embodiment.

[Device Structure] FIG. 4 is a conceptual diagram of the discharge light emitting device used in the second embodiment. The discharge light emitting device of FIG. 4 is a first substrate of a pair of substrates sandwiching a discharge space.
Two kinds of electrodes, substantially parallel to each other, on the inner surface of the first electrode, the first electrode
1, a second electrode 2, a dielectric layer 13, a protective film 14, and a dielectric film 15; a reflective layer 16 that reflects visible light on the inner surface of the other second substrate 12; And a phosphor 17. The dielectric layer and the protective film are formed on the entire surface of the electrode, and the dielectric film on the dielectric layer and the protective film is formed only on a part of the electrode (only a part where discharge is concentrated).

The protective film is for protecting the dielectric layer and the electrodes from sputtering by electric discharge, and is preferably made of a material such as SiO ₂ having a low secondary electron emission coefficient γ in view of the relationship with the dielectric film.
The dielectric film is preferably made of a material having a high secondary electron emission coefficient γ,
MgO is common, but not particularly limited.

Hereinafter, a mechanism for concentrating the discharge will be described. In the present embodiment, the mechanism for concentrating the discharge is realized by the shape of the dielectric film formed directly or indirectly on the electrode. In the example of FIG. 4, a dielectric film having a high secondary electron emission coefficient γ is formed on a part of the electrode, and discharge is easily formed only in this part. The optimum shape of the dielectric film may be selected from the balance between the degree of discharge concentration and the degree of discharge current suppression described below. This dielectric film provides a trigger for facilitating local initiation of discharge. In addition to the above, as a means for giving a trigger for facilitating the local formation of a discharge, for example, as shown in FIG. 5, the third electrode 3 can be arranged along the shape of the discharge.

By driving a device having such a mechanism for concentrating discharge by the driving method of the first embodiment, a luminance of 7000 cd / m ^{2 and} a luminance of 30 lm / W are obtained in the same experiment as in the first embodiment. Luminous efficiency was obtained.

Next, the case where the protective film is formed uniformly on the electrode and the case where it is not formed at all are described. These cases are the same as those in the first embodiment in which no projection is provided on the electrode. When the protective film was formed uniformly, the luminance was 5000 cd / m ^{2 and} the luminance was 15 lm / m ^{2 in} the same experiment as in the first embodiment.
With respect to the luminous efficiency of W, the luminance of 4000 cd / m ² and the luminous efficiency of 8 lm / W were obtained in the same experiment as in Embodiment 1 when no protective film was formed. From these results, it can be seen that the provision of the means for concentrating the discharge and the means for suppressing the discharge current caused by the discharge makes it possible to realize a discharge light emitting device with high luminance and high luminous efficiency.

Embodiment 3 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The discharge light emitting device, the driving method, the illuminating device and the display device described in the present embodiment are characterized in that they have means for concentrating the discharge and means for suppressing the discharge current caused by the discharge. The gas discharge is formed by applying a voltage between the electrodes,
The means for suppressing the discharge current is realized by reducing the applied voltage at the timing of suppressing the discharge current.

Hereinafter, the present embodiment will be described with reference to specific examples, but embodiments of the present invention are not limited thereto.

The discharge light emitting device of the third embodiment is basically the same as that of the first embodiment, but differs in a means for suppressing a discharge current. Hereinafter, only different portions will be described. The device structure, the lighting device, and the display device are the same as those in the first embodiment.

[Driving Method] FIG. 6 shows that the first electrode 1
3 shows a voltage waveform applied to the second electrode 2. FIG. 2A shows a voltage waveform applied to the first electrode 1 and FIG. 2B shows a voltage waveform applied to the second electrode 2.

In FIG. 6, the voltage of the second electrode 2 changes from Hi to Lo,
Only the period in which the voltage of the first electrode 1 changes from Lo to Hi is shown. During the discharge period, the voltage of the second electrode 2 changes from Hi to Lo.
The period when the voltage of the first electrode 1 changes from Lo to Hi, the voltage of the first electrode 1 changes from Hi to Lo, and the voltage of the second electrode 2 changes from Lo to
Light is emitted continuously by repeating the period of changing to Hi. However, it is not necessary to repeatedly invert the applied voltage unless the electrode is covered with the dielectric layer. The voltage waveform does not necessarily have to be a rectangular wave, but may be a sine wave or the like. It is generally advantageous that the rising speed of the applied voltage is small because the discharge is easily concentrated. Alternatively, a voltage may be applied such that one of the electrodes is always Hi. In this case, it is desirable that the wall charges be erased to some extent within one cycle by self-erasing discharge or the like.

First, during the period when the voltage of the second electrode 2 changes from Hi to Lo, the potential difference between the first electrode 1 and the second electrode 2 is reduced, and the capacitor of the device is discharged. At this time, a self-erasing discharge can be generated, and a subsequent discharge can be generated using the self-erasing discharge as a trigger.

Subsequently, during a period in which the voltage of the first electrode 1 changes from Lo to Hi, a potential difference is generated between the first electrode 1 and the second electrode 2 so that the first electrode 1 becomes positive and the second electrode becomes positive. Charge the device with 2 negative.

Next, when the electric field intensity between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge starts. Here, by designing the projections of the electrodes so that the lines of electric force concentrate and the electric field strength is increased, discharge can be started at these projections. As a result, the discharge concentrates on the protruding portion without spreading over the entire area between the electrodes.

When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet light generated by the discharge excites the phosphor to emit light. At this time, the discharge current starts to flow at once, but the voltage applied between the electrodes is reduced at a timing to suppress the increase of the discharge current. Here, reducing the voltage applied between the electrodes means reducing the potential difference between the electrodes. For example, in addition to reducing the voltage applied to the first electrode 1, by applying a voltage to the second electrode 2 as shown in FIG. 6, the potential difference between the electrodes can be reduced and the discharge current can be suppressed.

Further, a stable discharge current can be obtained by increasing or decreasing the potential difference between the electrodes at the timing of suppressing the fluctuation of the discharge current. When actually observing the discharge current, it can be seen that the discharge current becomes small and has a gentle current waveform. At this time, observing the positive column shows that it is very strong and stable.

According to such a driving method, the first embodiment
In the same experiment as above, a luminance of 7000 cd / m ² and a luminous efficiency of 25 lm / W were obtained.

From these results, means for concentrating discharge,
In addition, it can be seen that the provision of the means for suppressing the discharge current caused by the discharge makes it possible to realize a discharge light emitting device or the like with high luminance and high luminous efficiency. In addition, the process of providing a potential difference between the electrodes does not necessarily need to be performed by charging the device, and may use, for example, device discharge (not gas discharge). That is, the first electrode 1,
It is also possible to change the second electrode 2 from the Hi, Hi state to the Lo, Hi state.

Embodiment 4 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0110] The discharge light emitting device, the driving method, the lighting device, and the display device described in this embodiment are characterized in that they have means for concentrating discharge and means for suppressing discharge current caused by the discharge. Further, a plurality of concentrated discharges are formed, and these are separated by partition walls.

Hereinafter, the present embodiment will be described with reference to specific examples, but the embodiments of the present invention are not limited thereto.

The discharge light emitting device of the fourth embodiment is basically the same as that of the first embodiment, except that a partition is provided to control the positive column.

Hereinafter, only different portions will be described. Driving method,
The lighting device and the display device are the same as those in the first embodiment.

[Device Structure] FIG. 7 shows a conceptual diagram of the discharge light emitting device used in the fourth embodiment. (A) is a plan view, and (b) and (c) are cross-sectional views. The discharge light emitting device of FIG. 7 includes two types of electrodes substantially parallel to each other on the inner surface of one first substrate 11 of a pair of substrates sandwiching a discharge space, a first electrode 1,
A second electrode, a dielectric layer, and a protective film; a reflective layer for reflecting visible light; a partition wall for partitioning a discharge space; Phosphor 17
And

As the material of the partition walls, it is common to use low melting point glass, but there is no particular limitation. Further, the shape of the partition can be designed in accordance with the shape of the discharge. The partition does not necessarily need to be in contact with both the first substrate 11 and the second substrate 12.

The effect of the partition will be described below. First, by providing a wall or the like near the positive column discharge, the discharge can be easily controlled. For example, a plurality of concentrated discharges can be formed by a mechanism and / or means as described in Embodiment 1, but a very stable positive column can be formed by controlling each discharge by a partition provided in the vicinity of each discharge. Can be obtained. In particular, when the discharge is concentrated, it is generally effective to control the discharge, which is very effective. The shape such as the height of the partition wall is an important parameter for discharge control.

Second, by providing irregularities in the shape inside the device, the phosphor surface area can be increased and the luminance can be increased.

Third, by using the partition as a spacer, a device that is hard to crack can be realized.

With such a device structure, it was possible to obtain a luminance of 9000 cd / m ² and a luminous efficiency of 35 lm / W in the same experiment as in the first embodiment.

From these results, means for concentrating discharge,
In addition, by having a means for suppressing a discharge current caused by the discharge, a plurality of concentrated discharges are formed and these are separated by partition walls, so that high brightness,
It can be seen that a discharge light emitting device with high luminous efficiency can be realized.

Embodiment 5 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The discharge light-emitting device, the driving method, the lighting device, and the display device described in this embodiment are characterized by including means for concentrating discharge and means for suppressing discharge current caused by the discharge. In addition, a concentrated discharge is formed, thereby emitting light, and a mechanism for diffusing the emitted light is provided.

Hereinafter, the present embodiment will be described with reference to specific examples, but the embodiments of the present invention are not limited thereto.

The discharge light emitting device of the fifth embodiment is basically the same as that of the first embodiment, but is provided with a mechanism for diffusing light emission.

Hereinafter, only different portions will be described. Driving method,
The lighting device and the display device are the same as those in the first embodiment.

[Device Structure] FIG. 8 is a conceptual diagram of the discharge light emitting device used in the fifth embodiment. The discharge light emitting device of FIG. 8 is a first substrate of one of a pair of substrates sandwiching a discharge space.
Two kinds of electrodes, substantially parallel to each other, on the inner surface of the first electrode, the first electrode
1, having a second electrode 2, a dielectric layer 13, a protective film 14, and a dielectric film 15; a diffusion plate 19 on the outer surface of the first substrate 11; A reflective layer 16 that reflects visible light, and a phosphor 17 that emits light by discharge.

The mechanism for diffusing light emission is not particularly limited as long as it changes the direction of light emission from the light source.
For example, one that has a prism shape or an uneven shape on one side and diffuses light by setting appropriate reflectance and transmittance, and one that has an appropriate hole to secure light emission from the light source, etc. Conceivable.

These shapes and arrangements are optimally designed according to the arrangement and intensity of concentrated discharge.

The light emission is made uniform by this diffusion mechanism.

Embodiment 6 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The plasma display panel, the driving method, and the display device described in the present embodiment can control the light emission by gas discharge for each pixel, and can concentrate the discharge, and can reduce the light emission caused by the discharge. A means for suppressing the discharge current to be generated.

Further, the gas discharge is formed by applying a voltage between the electrodes, and a means for concentrating the discharge is realized by the shape of the electrodes.

Further, the gas discharge is formed by applying a voltage between the electrodes, and the means for suppressing the discharge current is realized by connecting an inductance in series to at least one of the electrodes. Features.

Hereinafter, the present embodiment will be described with reference to specific examples, but embodiments of the present invention are not limited thereto.

[Panel Structure] FIG. 9 is a conceptual diagram of a plasma display panel used in the sixth embodiment. FIG.
The plasma display panel has two types of electrodes, substantially parallel to each other, a first electrode 1, a second electrode 2, a dielectric layer 13, A first substrate on the inner surface of the second substrate;
It has a third electrode 3 formed in a direction intersecting with the electrode 1, a reflective layer 16 for reflecting visible light, a partition 18 for partitioning a discharge space, and a phosphor 17 which emits light by discharge. 1st electrode 1
The distance between the electrodes of the second electrode 2 is 0.2
mm or more.

The material of the substrate is generally soda lime glass, but is not particularly limited. The electrodes are generally formed of silver or chromium / copper / chrome (laminated structure), but are not particularly limited. As a material for the partition walls, a low-melting glass is generally used, but is not particularly limited. The phosphor is excited by the ultraviolet light generated by the discharge,
There is no particular limitation as long as it emits light. As the material of the dielectric, low melting glass is generally used, but is not particularly limited. The protective film is preferably made of a material having a high secondary electron emission coefficient γ, and is generally MgO, but is not particularly limited. The discharge gas is generally a mixed gas of at least one of He, Ne, and Ar and Xe or Xe gas, but is not particularly limited. The electrodes do not necessarily need to be covered with a dielectric layer or a protective film. Also, the first electrode 1 and the second electrode 2 need not necessarily be formed on the inner surface of the same substrate. Also, the form of the discharge does not necessarily have to be a positive column, and therefore the distance between the first electrode 1 and the second electrode 2 is arbitrary. However, the luminous efficiency is greatly improved by the positive column discharge, and the present invention is particularly effective when the positive column discharge is used.

Hereinafter, a mechanism for concentrating the discharge will be described. In the present embodiment, the mechanism for concentrating the discharge is realized by the shape of the electrode. In the example of FIG. 9, a protrusion is formed on a part of the electrode, and when applying a voltage between the electrodes, the lines of electric force are concentrated and the electric field strength is increased. The shape of the protruding portion may be selected from an optimum shape based on the balance between the degree of concentration of discharge and the degree of suppression of discharge current described later. If the discharge can be concentrated, the projection is not necessarily required. For example, the discharge can be concentrated by reducing the distance between the electrodes only in a certain region of the electrodes.

Here, the mechanism for concentrating the discharge need not necessarily be formed on both the first electrode 1 and the second electrode 2. For example, if a projection is provided on the first electrode 1 in a certain discharge area and the second electrode 2 is formed in a linear shape, the discharge is concentrated on the first electrode 1 side, and in this area, a triangular discharge shape is obtained. If 2 is an arc shape, it will be a fan-shaped discharge shape. When a plurality of these are formed, a projection may be provided only on the first electrode 1 in one region, and a projection may be provided only on the second electrode 2 in another region. Also, it is not always necessary to form a plurality. The roles of the two types of electrodes do not necessarily need to be different, and may be completely equivalent. That is, the polarity of the applied voltage to each electrode may be fixed, or may be alternately switched.

Next, the means for suppressing the discharge current will be described. In the present embodiment, the mechanism or means for suppressing the discharge current is realized by connecting an inductance in series to at least one of the electrodes. At this time, it is not always necessary to generate a back electromotive force (for example, an inductance) as long as it has the effect of suppressing the discharge current.

[0139] These effects will be described below using an example of driving by a driving method.

[Driving Method] FIG. 10 shows the first driving method during the sustain period of discharge.
3 shows a voltage waveform applied to the electrode 1, the second electrode 2, and the third electrode 3. 2A shows a voltage waveform applied to the first electrode 1, FIG. 2B shows a voltage waveform applied to the second electrode 2, and FIG. 2C shows a voltage waveform applied to the third electrode 3. The waveform is shown. FIG. 10 shows only a period in which the voltage of the second electrode 2 changes from Hi to Lo and the voltage of the first electrode 1 changes from Lo to Hi. This voltage waveform is an output waveform from the circuit, and the voltage waveform actually applied to the electrodes changes due to the inductance described later.

In the sustain period of the discharge, the voltage of the second electrode 2 becomes H
The period during which the voltage of the first electrode 1 changes from Lo to Hi, the voltage of the first electrode 1 changes from Hi to Lo, and the voltage of the second electrode 2 changes from i to Lo.
Light is emitted continuously by repeating the period from Lo to Hi. However, it is not necessary to repeatedly invert the applied voltage unless the electrode is covered with the dielectric layer.
The voltage waveform does not necessarily have to be a rectangular wave, but may be a sine wave or the like. It is generally advantageous that the rising speed of the applied voltage is small because the discharge is easily concentrated. Alternatively, a voltage may be applied such that one of the electrodes is always Hi. In this case, it is desirable that the wall charges be erased to some extent within one cycle by self-erasing discharge or the like.

First, during the period when the voltage of the second electrode 2 changes from Hi to Lo, the potential difference between the first electrode 1 and the second electrode 2 is reduced to discharge the capacitor of the panel. At this time, a self-erasing discharge can be generated, and a subsequent discharge can be generated using the self-erasing discharge as a trigger.

Subsequently, during the period in which the voltage of the first electrode 1 changes from Lo to Hi, a potential difference is generated between the first electrode 1 and the second electrode 2 so that the first electrode 1 becomes positive and the second electrode 2 becomes positive. The panel is charged with 2 negative.

Next, when the electric field intensity between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge starts. Here, by designing the projections of the electrodes so that the lines of electric force concentrate and the electric field strength is increased, discharge can be started at these projections. As a result, the discharge concentrates on the protruding portion without spreading over the entire area between the electrodes.

When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet light generated by the discharge excites the phosphor to emit light. At this time, the discharge current starts to flow at once, but a counter electromotive force is generated by the inductance connected in series to at least one of the electrodes, and the discharge current is suppressed. At this time, it is not always necessary to generate a back electromotive force (for example, an inductance) as long as it has the effect of suppressing the discharge current. Further, the inductance may be connected at a timing for suppressing an increase in the discharge current, or may be connected in advance. Since the optimum value of the inductance varies depending on the capacity of the panel, the inductance may be selected in accordance with the capacity of the panel so as to appropriately suppress the discharge current.

When the discharge current is actually observed, it can be seen that the discharge current becomes small and has a gentle current waveform. This is because the inductance generates back electromotive force in a self-adjusting manner due to a change in the discharge current, and thus suppresses not only the discharge current but also the fluctuation of the discharge current. At this time, observing the positive column shows that it is very strong and stable.

By driving in this manner, a luminance of 500 cd / m ² and a luminous efficiency of 4 lm / W could be obtained with a mixed gas of Xe and Ne (Xe is 10%).

Next, the case where no projection is provided on the electrode will be described. If no protruding part is provided on the electrode, select the optimal condition to discharge one cell (unit light emitting area)
Can be spread over the entire surface. The optimum conditions can be found by exclusively examining the conditions of the pulse width and the timing of the applied voltage. However, in general, it is a reality that the drive margin is narrow and difficult to control. If the optimization is not performed, the discharge concentrates. However, since the discharge concentrated in this way is not controlled at all, it moves spatially with time and becomes unstable. Therefore, when no protrusion is provided on the electrode, the most appropriate driving method is to drive the discharge by spreading the discharge over the entire surface of one cell.

However, in the driving method in which the discharge is spread over the entire surface, the discharge current is small but the luminance is low and the operation margin is narrow. Therefore, when the driving voltage is increased to increase the luminance, the discharge is concentrated and the control is difficult. . When the Xe partial pressure is increased, the luminous efficiency is increased, but the operation margin is further narrowed, which is not practical. In the case where no protruding portion was provided on the electrode, a similar experiment was conducted.
Luminance of 0 cd / m ² and luminous efficiency of ² lm / W were obtained.

Next, the case where the inductance is not connected, the size of the connection does not match the capacity of the panel, or the case where the inductance is connected at an inappropriate timing will be described. In such a case, it can be seen that the current flows at once when the discharge starts. Although the discharge is concentrated and localized, the discharge current over the entire surface is greater than when the discharge is spreading. As described above, as the discharge current increases, the ratio of contribution to light emission decreases, so that the light emission efficiency extremely decreases. In fact, when the discharge current was not suppressed in this manner, 400 cd / m ²
And a luminous efficiency of 0.5 lm / W.

From these results, means for concentrating the discharge,
In addition, it can be seen that a plasma display panel with high luminance and high luminous efficiency can be realized by having a means for suppressing a discharge current caused by the discharge.

The process of providing a potential difference between the electrodes does not necessarily have to be performed by charging the panel, but may use, for example, panel discharge (not gas discharge). That is, the first electrode 1 and the second electrode 2 are changed from Hi state to L state.
o, it is also possible to set to Hi state.

[Display Apparatus] The scan electrode, sustain electrode and address electrode shown below are, for example, the above-mentioned first electrode 1, second electrode 2 and third electrode 3.

FIG. 11 is a block diagram showing the configuration of the display device according to the present embodiment. 11 includes a PDP 100, an address driver 110, a scan driver 120, a sustain driver 130, a discharge control timing generation circuit 140, an A / D converter (analog-to-digital converter) 151, a scan number converter 152, and a subfield. It includes a conversion unit 153.

The PDP 100 includes a plurality of address electrodes, a plurality of scan electrodes (scan electrodes), and a plurality of sustain electrodes (sustain electrodes). The plurality of address electrodes are arranged in the vertical direction of the screen, and the plurality of scan electrodes and the plurality of scan electrodes are arranged. The sustain electrodes are arranged in the horizontal direction of the screen. The plurality of sustain electrodes are commonly connected. A discharge cell is formed at each intersection of the address electrode, the scan electrode, and the sustain electrode, and each discharge cell forms a pixel on a screen.

By applying a write pulse to the PDP 100 between the address electrode and the scan electrode, an address discharge is performed between the address electrode and the scan electrode to select a discharge cell. During this period, a sustain discharge is applied between the scan electrode and the sustain electrode by applying a periodic sustain pulse that is alternately inverted, and display is performed.

As a gradation display driving method in the AC type PDP, for example, ADS (Address and Display-period Sep.)
arated: address / display period separation) method can be used. FIG. 12 is a diagram for explaining the ADS method.
The vertical axis in FIG. 12 indicates the scanning direction (vertical scanning direction) of the scan electrodes from the first line to the m-th line, and the horizontal axis indicates time. In the ADS method, one field (1/60 second = 16.77 ms) is temporally divided into a plurality of subfields. For example, 8
When displaying 256 gradations in bits, one field is divided into eight subfields. Each subfield is divided into an address period in which an address discharge for selecting a lighting cell is performed and a sustain period in which a sustain discharge for display is performed. In the ADS method, scanning by address discharge is performed on the entire surface of the PDP from the first line to the m-th line in each subfield, and sustain discharge is performed when the entire address discharge is completed.

First, the video signal VD is input to an A / D converter. Further, the horizontal synchronizing signal H and the vertical synchronizing signal V
Is supplied to a discharge control timing generation circuit, an A / D converter, a scan number converter, and a subfield converter. A /
The D converter converts the video signal VD into a digital signal, and provides the image data to a scan number conversion unit. The scanning number conversion unit converts the image data into image data of the number of lines corresponding to the number of pixels of the PDP, and supplies the image data of each line to the subfield conversion unit.

The subfield conversion unit divides each pixel data of the image data for each line into a plurality of bits corresponding to a plurality of subfields, and serializes each bit of each pixel data for each subfield to an address driver. Output to The address driver is connected to the power supply circuit 111, converts data serially provided for each subfield from the subfield conversion unit to parallel data, and drives a plurality of address electrodes based on the parallel data.

The discharge control timing generation circuit generates discharge control timing signals SC and SU based on the horizontal synchronizing signal H and the vertical synchronizing signal V, and supplies them to the scan driver and the sustain driver, respectively. The scan driver includes an output circuit 121 and a shift register 122. The sustain driver includes an output circuit 131 and a shift register 132. These scan driver and sustain driver are connected to a common power supply circuit 123.

The shift register of the scan driver supplies the discharge control timing signal SC supplied from the discharge control timing generation circuit to the output circuit while shifting in the vertical scanning direction. The output circuit sequentially drives the plurality of scan electrodes in response to the discharge control timing signal SC provided from the shift register.

The shift register of the sustain driver supplies the discharge control timing signal SU supplied from the discharge control timing generation circuit to the output circuit while shifting in the vertical scanning direction. The output circuit sequentially drives the plurality of sustain electrodes in response to the discharge control timing signal SU provided from the shift register.

FIG. 13 is a timing chart showing the driving voltage applied to each electrode of PDP 100. In FIG. 13, the address electrode, the sustain electrode, and the nth line to
The drive voltage of the (n + 2) th scan electrode is shown.

Here, n is an arbitrary integer. As shown in FIG. 13, during the light emission period, a sustain pulse Psu is applied to the sustain electrode at a constant cycle. During the address period, a write pulse Pw is applied to the scan electrode. A write pulse Pwa is applied to the address electrode in synchronization with the write pulse. ON / OFF of the write pulse Pwa applied to the address electrode is controlled according to each pixel of the image to be displayed.

When the write pulse Pw and the write pulse Pwa are applied at the same time, an address discharge occurs at the discharge cell at the intersection of the scan electrode and the address electrode, and the discharge cell is turned on. In the sustain period after the address period, a sustain pulse Psc is applied to the scan electrode at a constant cycle. The phase of the sustain pulse Psc applied to the scan electrode is shifted by 180 degrees from the phase of the sustain pulse Psc applied to the sustain electrode. In this case, the sustain discharge occurs only in the discharge cells lit by the address discharge.

At the end of each subfield, an erase pulse Pe is applied to the scan electrodes. Thereby, the wall charge of each discharge cell is reduced to such an extent that disappearance or sustain discharge does not occur, and the sustain discharge ends. In the pause period after the application of the erase pulse Pe, the pause pulse Pr is applied to the scan electrode at a constant cycle. This pause pulse Pr is a sustain pulse Psu
And in phase.

The details of the driving method during the sustain period are as described in the above [Driving Method].

Embodiment 7 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The plasma display panel, the driving method, and the display device described in the present embodiment can control the light emission due to gas discharge for each pixel, and can concentrate the discharge and cause the discharge. A means for suppressing the discharge current to be generated.

The gas discharge is formed by applying a voltage between the electrodes, and the shape of the dielectric film formed directly or indirectly on the electrodes realizes a means for concentrating the discharge. It is characterized by the following.

Hereinafter, the present embodiment will be described with reference to specific examples, but the embodiments of the present invention are not limited thereto.

The plasma display panel of the seventh embodiment is basically the same as that of the sixth embodiment, but differs in a mechanism for concentrating discharge. Hereinafter, only different portions will be described. The driving method and the display device are the same as in the sixth embodiment.

[Panel Structure] FIG. 14 is a conceptual diagram of a plasma display panel used in the seventh embodiment. The plasma display panel of FIG. 14 has two types of electrodes substantially parallel to each other, a first electrode 1 and a second electrode 2, and a dielectric layer 13 on the inner surface of one first substrate 11 of a pair of substrates sandwiching a discharge space.
A third film having a protective film and a dielectric film formed on the inner surface of the other second substrate in a direction crossing the first electrode;
It has an electrode 3, a reflective layer 16 that reflects visible light, and a phosphor 17 that emits light by discharge.

The protective film is for protecting the dielectric layer and the electrodes from sputtering by electric discharge, and is preferably made of a material such as SiO ₂ having a low secondary electron emission coefficient γ in relation to the dielectric film.
The dielectric film is preferably made of a material having a high secondary electron emission coefficient γ,
MgO is common, but not particularly limited.

Hereinafter, a mechanism for concentrating the discharge will be described. In the present embodiment, the mechanism for concentrating the discharge is realized by the shape of the dielectric film formed directly or indirectly on the electrode. In the example of FIG. 14, a dielectric film having a high secondary electron emission coefficient γ is formed on a part of the electrode,
The discharge is easily formed only in this portion.
The optimum shape of the dielectric film may be selected from the balance between the degree of discharge concentration and the degree of discharge current suppression described below. This dielectric film provides a trigger for facilitating local initiation of discharge.

By driving the plasma display panel having such a mechanism for concentrating discharge by the driving method of the sixth embodiment, a luminance of 400 cd / m ² , 3.5 lm / W luminous efficiency was obtained.

Next, a case where a protective film is formed uniformly on an electrode and a case where no protective film is formed will be described. These cases are the same as those in the sixth embodiment in which no projection is provided on the electrode. When the protective film was formed uniformly, a luminance of 300 cd / m ^{2 and 2} lm / W in the same experiment as in the sixth embodiment.
In the case where no protective film was formed, a luminance of 150 cd / m ² and a luminous efficiency of 0.6 lm / W were obtained in the same experiment as in the sixth embodiment. From these results, it can be seen that a plasma display panel with high luminance and high luminous efficiency can be realized by having means for concentrating discharge and means for suppressing discharge current caused by the discharge.

Embodiment 8 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0179] The discharge light emitting device, the driving method, the lighting device, and the display device described in this embodiment are characterized in that they have means for concentrating discharge and means for suppressing discharge current caused by the discharge.

Further, the gas discharge is formed by applying a voltage between the electrodes, and the means for suppressing the discharge current is realized by reducing the applied voltage at a timing for suppressing the discharge current. It is characterized by.

Hereinafter, the present embodiment will be described with reference to specific examples, but embodiments of the present invention are not limited thereto.

The plasma display panel of the eighth embodiment is basically the same as the sixth embodiment, but differs in the means for suppressing the discharge current. Hereinafter, only different portions will be described. Embodiment 6: Panel structure and display device
Is the same as

[Driving Method] FIG. 15 shows the first driving method during the sustain period of discharge.
3 shows a voltage waveform applied to the electrode 1, the second electrode 2, and the third electrode 3. 2A shows a voltage waveform applied to the first electrode 1, FIG. 2B shows a voltage waveform applied to the second electrode 2, and FIG. 2C shows a voltage waveform applied to the third electrode 3. The waveform is shown. FIG. 15 shows only a period in which the voltage of the second electrode 2 changes from Hi to Lo and the voltage of the first electrode 1 changes from Lo to Hi. During the sustain period of discharge, the voltage of the second electrode 2 changes from Hi to Lo.
The period when the voltage of the first electrode 1 changes from Lo to Hi, the voltage of the first electrode 1 changes from Hi to Lo, and the voltage of the second electrode 2 changes from Lo to
Light is emitted continuously by repeating the period of changing to Hi. However, it is not necessary to repeatedly invert the applied voltage unless the electrode is covered with the dielectric layer.

The voltage waveform does not necessarily have to be a rectangular wave, but may be a sine wave or the like. It is generally advantageous that the rising speed of the applied voltage is small because the discharge is easily concentrated.
Alternatively, a voltage may be applied such that one of the electrodes is always Hi. In this case, by self-erasing discharge, etc.
It is desirable that the wall charges be erased to some extent within one cycle.

First, during the period when the voltage of the second electrode 2 changes from Hi to Lo, the potential difference between the first electrode 1 and the second electrode 2 is reduced to discharge the capacitor of the panel. At this time, a self-erasing discharge can be generated, and a subsequent discharge can be generated using the self-erasing discharge as a trigger.

In the subsequent period in which the voltage of the first electrode 1 changes from Lo to Hi, a potential difference is generated between the first electrode 1 and the second electrode 2 to make the first electrode 1 positive and the second electrode The panel is charged with 2 negative.

Next, when the electric field intensity between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge starts. Here, by designing the projections of the electrodes so that the lines of electric force concentrate and the electric field strength is increased, discharge can be started at these projections. As a result, the discharge concentrates on the protruding portion without spreading over the entire area between the electrodes.

When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet light generated by the discharge excites the phosphor to emit light. At this time, the discharge current starts to flow at once, but the voltage applied between the electrodes is reduced at a timing to suppress the increase of the discharge current. Here, reducing the voltage applied between the electrodes means reducing the potential difference between the electrodes. For example, in addition to reducing the voltage applied to the first electrode 1, by applying a voltage to the second electrode 2 as shown in FIG. 15, the potential difference between the electrodes can be reduced and the discharge current can be suppressed.

Further, a stable discharge current can be obtained by increasing or decreasing the potential difference between the electrodes at the timing of suppressing the fluctuation of the discharge current. When actually observing the discharge current, it can be seen that the discharge current becomes small and has a gentle current waveform. At this time, observing the positive column shows that it is very strong and stable.

According to such a driving method, the sixth embodiment can be used.
In the same experiment as above, a luminance of 300 cd / m ² and a luminous efficiency of 3 lm / W were obtained.

From these results, means for concentrating discharge,
In addition, it can be seen that a plasma display panel with high luminance and high luminous efficiency can be realized by having a means for suppressing a discharge current caused by the discharge.

The process of providing a potential difference between the electrodes does not necessarily have to be performed by charging the panel, and may use, for example, panel discharge (not gas discharge). That is, the first electrode 1 and the second electrode 2 are changed from Hi state to L state.
o, it is also possible to set to Hi state.

[0193]

As is apparent from the embodiment of the present invention, a very strong and stable positive column discharge is formed by having a means for concentrating discharge and a means for suppressing a discharge current caused by the discharge. It is possible to do. Accordingly, it is possible to provide a discharge light emitting device, a plasma display panel, a display device, and the like that can perform high-luminance, high luminous efficiency, and stable discharge.

[Brief description of the drawings]

FIG. 1 is a diagram showing a discharge light emitting device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a discharge light emitting device according to the first embodiment.

FIG. 3 is a diagram showing a voltage waveform applied to each electrode during a discharge period in the first embodiment.

FIG. 4 is a diagram showing a discharge light emitting device according to the second embodiment.

FIG. 5 is a diagram showing a discharge light emitting device according to the second embodiment.

FIG. 6 is a diagram showing a voltage waveform applied to each electrode during a discharge period according to the third embodiment.

FIG. 7 is a diagram showing a discharge light emitting device according to the fourth embodiment.

FIG. 8 is a diagram showing a discharge light emitting device according to the fifth embodiment.

FIG. 9 is a diagram showing a plasma display panel according to the sixth embodiment.

FIG. 10 is a diagram showing a voltage waveform applied to each electrode during a sustain period of discharge in the sixth embodiment.

FIG. 11 is a diagram showing a configuration of a display device according to the sixth embodiment.

FIG. 12 is a diagram showing an ADS method according to the sixth embodiment;

FIG. 13 is a diagram showing a drive voltage applied to each electrode of the PDP according to the sixth embodiment.

FIG. 14 is a diagram showing a plasma display panel according to the seventh embodiment.

FIG. 15 is a diagram showing a voltage waveform applied to each electrode during a sustain period of discharge in the eighth embodiment.

FIG. 16 is a view showing a conventional flat discharge lamp.

FIG. 17 is a view showing a conventional surface discharge type PDP having a three-electrode structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st electrode 2 2nd electrode 3 3rd electrode 11 1st substrate 12 2nd substrate 13 Dielectric layer 14 Protective film 15 Dielectric film 16 Reflective layer 17 Phosphor 18 Partition wall 19 Diffusion plate 20 Spacer 21 Scan electrode 22 Sustain electrode 23 Address electrode 100 PDP 110 Address driver 111 Address driver power supply circuit 120 Scan driver 121 Scan driver output circuit 122 Scan driver shift register 123 Common power supply circuit for scan driver and sustain driver 130 Sustain driver 131 Sustain driver output circuit 132 Sustain Driver shift register 140 Discharge control timing generation circuit 151 A / D converter 152 Scanning number converter 153 Subfield converter

Claims (17)

[Claims] 1. A discharge forming device comprising: means for concentrating a gas discharge; and means for suppressing a discharge current caused by the gas discharge. 2. A discharge light emitting device comprising: means for concentrating a gas discharge; and means for suppressing a discharge current caused by the gas discharge. 3. The discharge light emitting device according to claim 2, wherein the gas discharge is formed by applying a voltage between the electrodes, and the shape of the electrodes realizes a means for concentrating the gas discharge. 4. A gas discharge is formed by applying a voltage between the electrodes, and the shape of the dielectric film formed directly or indirectly on the electrodes provides a means for concentrating the gas discharge. 3. The discharge light emitting device according to 2. 5. A gas discharge is formed by applying a voltage between electrodes, and means for suppressing a discharge current is realized by connecting an inductance in series to at least one of the electrodes. The discharge light emitting device according to any one of the above. 6. A gas discharge is formed by applying a voltage between the electrodes, and means for suppressing the discharge current is realized by reducing the voltage at a timing at which the discharge current is suppressed. The discharge light emitting device according to claim 2. 7. The discharge light emitting device according to claim 2, wherein a plurality of concentrated discharges are formed by means for concentrating the gas discharge. 8. The discharge light emitting device according to claim 7, wherein a plurality of concentrated discharges are separated by partition walls. 9. The discharge light emitting device according to claim 2, further comprising means for emitting light by the discharge concentrated by the means for concentrating the gas discharge and diffusing the light emission. 10. An illuminating device configured to illuminate an illuminated object using the discharge light emitting device according to claim 2. Description: 11. A display device using the discharge light emitting device according to claim 2, or a lighting device according to claim 10. 12. A plasma display panel capable of performing display by controlling light emission by gas discharge for each pixel, comprising: means for concentrating discharge; and means for suppressing a discharge current caused by the discharge. Plasma display panel having: 13. The plasma display panel according to claim 12, wherein the gas discharge is formed by applying a voltage between the electrodes, and the shape of the electrodes realizes a means for concentrating the discharge. 14. A gas discharge is formed by applying a voltage between electrodes, and the shape of a dielectric film formed directly or indirectly on the electrodes realizes a means for concentrating the discharge. The plasma display panel according to claim 12, wherein 15. A gas discharge is formed by applying a voltage between electrodes, and means for suppressing a discharge current is realized by connecting an inductance in series to at least one of the electrodes. The plasma display panel according to any one of the above. 16. A gas discharge is formed by applying a voltage between electrodes, and means for suppressing the discharge current is realized by reducing the voltage at a timing at which the discharge current is suppressed. The plasma display panel according to any one of the above. 17. A display device using the plasma display panel according to claim 12.