JP2003272886A - Discharge light emitting device, driving method thereof, lighting device and display device using them - Google Patents

Abstract

[PROBLEMS] To provide a discharge light-emitting device that achieves high luminous efficiency and high luminous efficiency by eliminating wasteful power, a driving method thereof, and a lighting device and a display device using the same. [MEANS FOR SOLVING PROBLEMS] By causing a change in potential difference between electrodes,
In the method for driving a discharge light emitting device, wherein a gas discharge is generated to emit light, a positive discharge having the same polarity as the change in potential difference between the electrodes and a negative discharge having a different polarity from the polarity are continuously generated. A discharge light emitting device, a driving method thereof, and a lighting device and a display device using the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge light emitting device, a driving method thereof, and an illumination device and a display device using them.

[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, light weight, and low power consumption. However, since the liquid crystal itself is not a self-luminous element, a backlight that supplies light from the back surface of the liquid crystal panel is required for display. As the backlight, an edge light system in which a thin tube cold cathode fluorescent lamp is installed at the end of a light guide plate is generally used, but a direct system using a flat discharge lamp is also used.

FIG. 6 is a view showing a conceptual structure of a typical flat discharge lamp which has been conventionally used. In FIG. 6, (a) is a plan view of the flat discharge lamp,
(B) is a sectional view taken along line 6b-6b in (a) as seen from the front direction, and (c) is a sectional view taken along line 6c-6c in (a) seen from a side direction. The discharge light emitting device shown in FIG. 6 comprises a first substrate 11 made of glass, a second substrate 12 also made of glass, and a spacer 20 to form a discharge space, and one of a pair of substrates sandwiching the discharge space. On the inner surface of the first substrate 11 (front glass), the two types of electrodes substantially parallel to each other, the first electrode 1, the second electrode 2, and the dielectric layer 13, and the other second substrate 12 (rear surface). It has a phosphor 17 which emits light by discharge on the inner surface of (glass). The distance between the first electrode 1 and the second electrode 2 is 0.2 mm or more, which can form a positive column discharge. The phosphor 17 is applied to the inside of the second substrate 12. Mercury and rare gas are enclosed in the discharge space, and ultraviolet rays are generated by gas discharge,
The ultraviolet light excites the phosphor to emit light.

The method of driving the above flat discharge lamp is as follows.
A rectangular voltage waveform is alternately applied to the two electrodes on the front plate, and by appropriately selecting the period and pulse width of the rectangular wave, it is possible to obtain light emission that spreads uniformly over the entire discharge space. FIG. 7 shows a conceptual diagram of an applied voltage waveform and a discharge current waveform of the conventional typical flat discharge lamp described above.

[0005]

However, the conventional flat discharge lamp still has a problem that the luminous efficiency is low, the discharge starting voltage is high, and the brightness is low. It is also difficult to spread the light emission uniformly over the entire discharge space. It is considered that this is because the positive column cannot be used stably.

Various investigations have been made on the above-mentioned problems, and a patent is disclosed, for example, in Japanese Patent Laid-Open No. 9-02.
7298, JP-A-10-222083, JP-A-11
No. 07916/1999, JP-A No. 11-144678 and the like are mentioned, but sufficient results have not been obtained even if the above patent information is adopted.

As described above, the conventional flat discharge lamp has the problems of low luminous efficiency, high discharge starting voltage and low luminance.

An object of the present invention is to solve the above-mentioned problems, in particular, the problem of luminous efficiency, that is, a discharge light emitting device and a driving method thereof, which can stably utilize a positive column and realize high luminous efficiency and high luminous efficiency. Another object of the present invention is to provide a lighting device and a display device using them.

[0009]

According to the method of driving a discharge light emitting device of the present invention, a voltage is applied between electrodes to generate a positive discharge and a positive discharge current is caused to flow to emit light, and the positive discharge continues. Then, the positive discharge current is forcibly reduced or the positive discharge current is forcibly stopped by generating a negative discharge. Here, as the means for generating the negative discharge, for example, reducing the potential difference between the electrodes, generating a counter electromotive force in the circuit, and the like can be considered.

In the conventional example, when a voltage is applied between the electrodes (point a in FIG. 7) to start the discharge, the ions ionized by the discharge are moved by the electric field and accumulated as wall charges, and the inside of the opposite direction is accumulated. An electric field is generated. Therefore, in the conventional technique in which the external voltage is fixed until the positive discharge ends, as shown in FIG. 7, a current flows to cancel the internal electric field by the external voltage. This is the discharge current observed outside.

However, the electric charges stored in the capacitance of the device by this discharge current are erased by the self-erasing discharge when the external voltage is set to 0 V (volt) (point c in FIG. 7) in a later process. Is discharged with the discharge (capacity discharge).
Therefore, the work of charging due to the gas discharge performed by the external voltage becomes useless due to the later discharge of the capacity.

On the other hand, the present invention can eliminate this useless charging and suppress the discharge current to the necessary minimum. The discharge current does not evenly contribute to the brightness. The earlier the discharge current, the stronger the electric field and the higher the brightness. Therefore, by suppressing the discharge current in the latter half, the discharge current can be minimized and the luminous efficiency can be improved. FIG. 1 shows a conceptual diagram of a typical applied voltage waveform and discharge current waveform of the present invention. Dotted lines indicate the conventional applied voltage waveform and discharge current waveform. The solid line shows the voltage-current waveform when the positive discharge is suppressed by the negative discharge in the present invention. In the dotted line, positive discharge (discharge current) and negative discharge (discharge current) are separated, but in the solid line, positive discharge (discharge current) and negative discharge (discharge current) are continuous, and positive discharge is negative. Is suppressed by the discharge of the positive discharge current.

Further, the discharge light emitting device of the present invention is characterized by combining the above-mentioned driving method and a mechanism for concentrating the discharge.

In general, gas discharge has a property of easily concentrating, especially when a rare gas is used. Once the discharge is concentrated, a uniform discharge cannot be obtained. Further, once the discharge is concentrated, the discharge current becomes excessive. However, since the flow of light locally becomes high brightness, but the efficiency drops considerably, the point of development was how to expand the discharge and achieve high efficiency. Further, the expansion of the positive column over the entire space is realized exclusively by the pulse width of the applied voltage, the timing, etc. However, in general, the drive margin of these is narrow and control is difficult. Since this tendency is remarkable as the gas pressure is increased, it is difficult to use these gas pressure regions having high efficiency.

On the other hand, the present invention intends to realize high brightness by intentionally concentrating the discharge, and simultaneously realize high efficiency by suppressing the discharge current flowing excessively by another means. As a result, a large drive condition margin can be secured, which facilitates control, and a region with a high gas pressure can be used, so that efficiency can be further improved.

In this specification, as a general rule, the expression “discharge” means gas discharge, and the discharge of the capacity of the device is expressed as “discharge of capacity”.
The present invention is a driving method of a discharge forming device characterized by causing a change in potential difference between electrodes to generate a gas discharge, and a positive discharge having the same polarity as the change in potential difference between electrodes, It is characterized in that a negative discharge having a polarity different from the polarity is continuously generated. By such a driving method, positive discharge can be controlled by negative discharge.

The present invention is also a method of driving a discharge forming device, characterized in that a potential difference is changed between electrodes to generate a gas discharge, and the polarity is the same as the change in potential difference between the electrodes. Discharge and a negative discharge having a polarity different from the polarity are continuously generated, and a positive discharge current is reduced by the generation of the negative discharge. With such a driving method, the positive discharge current is reduced by the occurrence of the negative discharge, and the latter half of the positive discharge current can be suppressed, so that wasteful power can be saved and highly efficient discharge can be obtained. Becomes

The present invention is also a method of driving a discharge forming device characterized in that a potential difference is changed between electrodes to generate a gas discharge, and the polarity is the same as that of the potential difference between the electrodes. And the negative discharge having a polarity different from the polarity are continuously generated, and the positive discharge current is stopped by the generation of the negative discharge. By such a driving method, the positive discharge is stopped by the occurrence of the negative discharge, and the latter half of the positive discharge current can be suppressed, so that it is possible to save wasteful power and obtain high-efficiency discharge. Become.

The present invention is also characterized in that continuous discharge is obtained by repeating the driving method described above. With such a driving method, since the latter half of the positive discharge current can be suppressed, it is possible to save wasteful power and continuously obtain high-efficiency discharge. Further, the polarities of the applied voltage when repeated may have the same sign or different signs. In particular, if the positive discharge is suppressed by the negative discharge, the wall charge is effectively reduced to a negligible level, so that continuous driving with the same sign is possible.

The present invention is also a discharge forming device characterized in that a discharge is formed by the driving method described above. With such a discharge forming device, since the latter half of the positive discharge current can be suppressed, it is possible to save wasteful power and obtain high-efficiency discharge. Furthermore, if a phosphor is excited by ultraviolet rays generated by discharge, a discharge light emitting device can be obtained.

The present invention is also a discharge forming device characterized by having a mechanism for concentrating the discharge and forming the discharge by the driving method described above. With such a discharge forming 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 unnecessary power and obtain a highly efficient discharge. Furthermore, if a phosphor is excited by ultraviolet rays generated by discharge, a discharge light emitting device can be obtained.

The present invention is also a driving method of a discharge light emitting device characterized in that a potential difference is changed between electrodes to generate a gas discharge to cause light emission. It is characterized in that the same positive discharge and a negative discharge having a polarity different from the polarity are successively generated. By such a driving method, positive discharge can be controlled by negative discharge.

The present invention is also a driving method of a discharge light emitting device, characterized in that a potential difference is changed between electrodes to generate a gas discharge to cause light emission. It is characterized in that the same positive discharge and a negative discharge having a polarity different from the polarity are successively generated, and a positive discharge current is reduced by the generation of the negative discharge.
With such a driving method, the positive discharge current is reduced by the occurrence of the negative discharge, and the latter half of the positive discharge current, which has a low contribution to the luminance, can be suppressed, so that wasteful power can be saved and high efficiency discharge can be achieved. It is possible to obtain high brightness and high luminous efficiency.

The present invention is also a method of driving a discharge light emitting device, characterized in that a potential difference is changed between electrodes to generate a gas discharge to cause light emission. It is characterized in that the same positive discharge and a negative discharge having a polarity different from the polarity are successively generated, and the positive discharge current is stopped by the generation of the negative discharge.
By such a driving method, the positive discharge is stopped by the occurrence of the negative discharge, and the latter half of the positive discharge current, which has a low contribution to the luminance, can be suppressed, so that wasteful power is saved and high-efficiency discharge is achieved. It is possible to obtain high luminance and high luminous efficiency.

The present invention is also characterized in that continuous light emission is obtained by repeating the driving method described above. With such a driving method, the latter half of the positive discharge current, which has a low contribution to the brightness, can be suppressed, so that it is possible to obtain high-efficiency discharge while saving wasteful power, achieving high brightness and high luminous efficiency. it can. Further, the polarities of the applied voltage when repeated may have the same sign or different signs. In particular, if the positive discharge is suppressed by the negative discharge, the wall charge is effectively reduced to a negligible level, so that continuous driving with the same sign is possible.

The present invention is also a discharge light emitting device characterized in that it emits light by the above-mentioned driving method. With such a discharge light emitting device, it is possible to suppress the latter half of the positive discharge current, which has a low contribution to brightness, so that it is possible to save wasteful power and obtain high-efficiency discharge. realizable.

The present invention is also a discharge light emitting device characterized by having a mechanism for concentrating a discharge and emitting light by the above-mentioned driving method. With such a discharge light emitting 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 unnecessary power and obtain a high-efficiency discharge. Luminous efficiency can be realized.

The present invention is also an illuminating device configured to illuminate an object to be illuminated using the above-mentioned discharge light emitting device. With such a lighting 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. An efficient backlight can be realized.

The present invention further provides a display device using the driving method, the discharge light emitting device, or the lighting device described above. With such a display device, it is possible to obtain a very strong discharge by concentrating the discharge.
By suppressing the discharge current, wasteful power can be saved and high-efficiency discharge can be obtained, and display with high brightness and high luminous efficiency can be realized.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. The discharge light emitting device described in this embodiment is characterized in that a potential difference is changed between electrodes to generate (or form) a gas discharge or emit light. Further, the driving method of the discharge light emitting device is such that a positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having the polarity different from the polarity are continuously generated, and a positive discharge current is supplied to the negative It is characterized in that it is reduced by the occurrence of discharge.

The first embodiment will be described below with reference to specific examples.

[Device Structure] FIG. 2 is a diagram showing a conceptual structure of the discharge light emitting device used in the first embodiment. In FIG. 2, (a) is a plan view, (b) is a front view, a cross-sectional view taken along line 2b-2b in (a), (c) is a side view, and (a) is 2c-2
It is sectional drawing in the c line. The discharge light emitting device according to this embodiment includes a first substrate 11 provided on the front side (light exit side) of the light emitting path and a second substrate provided on the back side (light emitting side) of the light emitting path. 12 and these first substrates 11
Further, the discharge space 21 is configured by the spacer 20 provided between the second substrate 12. In this embodiment, the first substrate 11 and the second substrate 12 are made of glass material, but are not necessarily limited to glass. The first substrate 11 which is one of the pair of substrates sandwiching the discharge space 21
On the inner surface of the (front glass), two types of electrodes that are substantially parallel to each other, a first electrode 1, a second electrode 2, a dielectric layer 13, and
The protective film 14 is provided, and on the inner surface of the other second substrate 12 (back glass), a reflective layer 15 that reflects visible light and a phosphor 17 that emits light by discharge are provided. The distance between the first electrode 1 and the second electrode 2 is 0.2 mm or more, which can form a positive column discharge. The phosphor 17 is provided on the inner surface of the reflective layer 15 by a method such as coating.

As the material of the substrate, soda lime glass is generally used, but it is not particularly limited. The electrode is generally formed of silver or chrome / copper / chrome (laminated structure), but is not particularly limited. The phosphor is not particularly limited as long as it is excited by ultraviolet rays generated by discharge and emits light. A low melting point glass is generally used as the material of the dielectric, but is not particularly limited. A material having a high secondary electron emission coefficient γ is desirable for the protective film.
O is common, but not particularly limited. Discharge gas is H
A mixed gas of at least one of e, Ne and Ar and Xe or a Xe gas is generally used, but is not particularly limited. Mercury may be used if necessary. Further, the structure of the device does not necessarily have to be flat, and may be a thin tube.
The electrodes do not necessarily have to be covered with a dielectric layer or a protective film. Further, the first electrode 1 and the second electrode 2 do not necessarily have to be formed on the inner surface of the same substrate. Also, the form of the discharge does not necessarily have to be the positive column, so the first
The distance between the 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.

In the present embodiment, the means for generating the negative discharge is realized by connecting an inductance in series to at least one of the electrodes. The inductance is not necessarily required as long as it has the effect of generating this negative discharge.

[Driving Method] FIG. 3 shows a conceptual diagram of an applied voltage waveform and a discharge current waveform in the present embodiment. In FIG. 3, the voltage of one electrode changes from Lo to Hi and from Hi to Lo.
It shows the period of change to. This voltage waveform represents the potential difference between the electrodes.

During the discharge period, 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 Hi and the second electrode. Light is emitted continuously by repeating the period in which the voltage of 2 changes from Hi to Lo. Further, the voltage waveform does not necessarily have to be a rectangular wave and may be a sine wave or the like. Further, the voltage may be applied so 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 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 2. 2 is negative to charge the device capacity. At this time, a voltage can be applied to the first electrode 1 beyond the power supply voltage by the inductance connected to the first electrode.

Next, when the electric field strength between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge (positive discharge) starts. When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet rays generated by the discharge excite the phosphor to emit light. At this time, the discharge current starts flowing all 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. Here, if the inductance is set appropriately, a negative discharge can be generated successively to the positive discharge. That is, by generating an appropriate counter electromotive force by the inductance, the external electric field created by the external voltage is weakened, and the internal electric field formed by the wall charges generated by the positive discharge overcomes this and self-erasing discharge is generated.

By controlling the positive discharge by the negative discharge, the positive discharge mainly contributing to the light emission can be made efficient.

Since the optimum size of the inductance varies depending on the capacitance of the device, it may be selected according to the capacitance of the device so that self-erasing discharge occurs.
The self-erase discharge can be controlled by the potential difference, the dimension of the device structure, the optimization of gas, etc., in addition to the above. Furthermore, a desired discharge can be obtained by removing the inductance with a switch as needed.

By this driving method, the originally required voltage shown by the dotted line in FIG. 3 can be considerably reduced, so that the load on the circuit is reduced. In the dotted line in FIG. 3, since a high voltage is continuously applied to the first electrode 1, the discharge current continues to flow until it matches the voltage. However, the electric charge stored in the capacitance of the panel due to this discharge current is discharged by the self-erasing discharge when the external voltage is set to 0 V (point b in FIG. 3) in the later process (capacity discharge). Therefore, the work of charging due to the discharge performed by the external voltage becomes useless due to the discharge of the later capacity.

On the other hand, the present invention can eliminate this useless charging and suppress the discharge current to the necessary minimum. That is, not only due to the weakening of the external electric field created by the external voltage, but also because the wall charges generated by the positive discharge due to the negative discharge are erased, the work due to unnecessary charging is eliminated,
The discharge current can be suppressed to the necessary minimum.

The discharge current does not evenly contribute to the brightness. The earlier the discharge current, the stronger the electric field and the higher the brightness. Therefore, by suppressing the discharge current in the latter half, the discharge current can be minimized and the luminous efficiency can be improved.

By driving in this way, a luminous efficiency of about 30 (lm / W: lumen / watt) could be obtained without using mercury.

The luminous efficiency was about 15 (1 m / W) when the device was driven by applying the voltage waveform shown by the dotted line in FIG.

From these results, a voltage is applied between the electrodes to generate a positive discharge, and a positive discharge current is caused to flow to emit light.
By generating a counter electromotive force in the circuit to generate a negative discharge, it is possible to reduce the positive discharge current, and it is possible to realize a discharge light emitting device with high brightness and high light emission efficiency. .

Here, the negative discharge does not necessarily have to be self-erasing discharge, and may be positively generated by a negative potential difference. The means for generating the negative discharge does not necessarily have to be an inductance, but may be generated by reducing the potential difference.

Further, the process of giving a potential difference between the electrodes does not necessarily have to be due to charging of the device, and for example, discharging of the capacitance of the device may be used. That is, the first electrode 1 and the second electrode 2 are changed from Hi and Hi states to Lo and H
It is also possible to enter the i state.

Further, in the example of FIG. 2, a discharge forming device is obtained by using no phosphor or separating the phosphor.

[Illumination Device] It can be realized by combining a circuit for realizing the above driving method with the above device.

[Display Device] It can be realized by combining the above-mentioned illumination device with, for example, a liquid crystal and a drive circuit for the liquid crystal.

(Embodiment 2) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A method for driving a discharge light emitting device described in the present embodiment is a method for driving a discharge light emitting device, which is characterized in that a potential difference is changed between electrodes to generate a gas discharge and emit light. Positive discharge with the same polarity as the change in the potential difference of
Continuing to generate a negative discharge with a polarity different from the polarity,
The positive discharge current is stopped by the occurrence of the negative discharge.

The present embodiment will be described below with reference to specific examples, but the embodiment of the present invention is not limited to this.

[Device structure], [Lighting device], and [Display device] in the second embodiment are the same as those in the first embodiment.

[Driving Method] FIG. 4 shows a conceptual diagram of an applied voltage waveform and a discharge current waveform in the present embodiment. In FIG. 4, the voltage of one electrode changes from Lo to Hi and from Hi to Lo.
It shows the period of change to. This voltage waveform represents the potential difference between the electrodes.

In the discharge period, 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 Hi and the second electrode. Light is emitted continuously by repeating the period in which the voltage of 2 changes from Hi to Lo. Further, the voltage waveform does not necessarily have to be a rectangular wave and may be a sine wave or the like. Further, the voltage may be applied so 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, in 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 to make the first electrode 1 positive and the second electrode 2. 2 is negative to charge the device capacity. At this time, a voltage can be applied to the first electrode 1 beyond the power supply voltage by the inductance connected to the first electrode.

Next, when the electric field strength between the first electrode 1 and the second electrode 2 exceeds a threshold value, discharge (positive discharge) starts. When the discharge starts, a discharge current flows between the first electrode 1 and the second electrode 2, and the ultraviolet rays generated by the discharge excite the phosphor to emit light. At this time, the discharge current starts flowing all 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. Here, if the inductance is set appropriately, a negative discharge can be generated successively to the positive discharge. That is, by generating an appropriate counter electromotive force by the inductance, the external electric field created by the external voltage is weakened, and the internal electric field formed by the wall charges generated by the positive discharge overcomes this and self-erasing discharge is generated.

By forcibly stopping the positive discharge by this negative discharge, the positive discharge mainly contributing to light emission can be made more efficient.

Since the optimum size of the inductance varies depending on the capacitance of the device, it may be selected according to the capacitance of the device so that self-erasing discharge occurs.
The self-erase discharge can be controlled by the potential difference, the dimension of the device structure, the optimization of gas, etc., in addition to the above. Furthermore, a desired discharge can be obtained by removing the inductance with a switch as needed.

By this driving method, the originally required voltage shown by the dotted line in FIG. 4 can be considerably reduced, so that the load on the circuit is reduced. In the dotted line of FIG. 4, the high voltage continues to be applied to the first electrode 1, so that the discharge current continues to flow until it matches the voltage. However, the electric charges stored in the capacitance of the panel due to this discharge current are discharged by the self-erasing discharge when the external voltage is set to 0 V (point b in FIG. 4) in the later process (capacity discharge). Therefore, the work of charging due to the discharge performed by the external voltage becomes useless due to the discharge of the later capacity.

On the other hand, according to the present invention, this useless charging can be eliminated and the discharge current can be suppressed to the necessary minimum. That is, not only by the weakening of the external electric field created by the external voltage, but also by stopping the positive discharge by the negative discharge, the wall charge generated by the positive discharge is erased, eliminating the work due to unnecessary charging, The discharge current can be suppressed to the necessary minimum.

The discharge current does not evenly contribute to the brightness. The earlier the discharge current, the stronger the electric field and the higher the brightness. Therefore, by suppressing the discharge current in the latter half, the discharge current can be minimized and the luminous efficiency can be improved.

By driving in this way, a luminous efficiency of about 35 (lm / W) could be obtained without using mercury.

When the voltage waveform shown by the dotted line in FIG. 4 was applied and driven, the luminous efficiency was about 15 (lm / W). From these results, a voltage is applied between the electrodes to generate a positive discharge, a positive discharge current is caused to flow to emit light, and a counter electromotive force is generated in the circuit to generate a negative discharge.
It can be seen that the positive discharge can be stopped and a discharge light emitting device with high luminance and high light emission efficiency can be realized.

Here, the negative discharge does not necessarily have to be self-erasing discharge, and may be positively generated by a negative potential difference. The means for generating the negative discharge does not necessarily have to be an inductance, but may be generated by reducing the potential difference.

Further, the process of providing a potential difference between the electrodes does not necessarily have to be due to charging of the device, and for example, discharging of the capacitance of the device may be used. That is, the first electrode 1 and the second electrode 2 are changed from Hi and Hi states to Lo and H
It is also possible to enter the i state.

Further, in the example of FIG. 2, a discharge forming device is obtained by using no phosphor or separating the phosphor.

(Embodiment 3) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The discharge light emitting device described in the present embodiment has a mechanism for concentrating the discharge, and emits light by the driving method according to any one of claims 7 to 10.

The present embodiment will be described below with reference to specific examples, but the embodiment of the present invention is not limited to this.

The discharge forming device, [driving method], [illuminating device], and [display device] in the third embodiment are the same as those in the first embodiment.

[Device Structure] FIG. 5 is a diagram showing a conceptual structure of the discharge light emitting device used in the third embodiment. 5A is a plan view, FIG. 5B is a front view, FIG. 5A is a cross-sectional view taken along line 5b-5b in FIG. 5A, and FIG. 5C is a side view. 5c-5
It is sectional drawing in the c line. Except for the mechanism for concentrating the discharge, it is the same as in the first embodiment.

The 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 shown in FIG. 5, protrusions are formed on a part of the electrodes, and when the voltage is applied between the electrodes, the lines of electric force are concentrated and the electric field strength is increased. The shape of the protrusion may be selected as an optimum shape from the balance of the degree of concentration of discharge and the degree of suppression of discharge current described later. If the discharge can be concentrated, it is not necessarily the protrusion. For example, it is possible to concentrate the discharge by narrowing the distance between the electrodes only in a region where the electrodes are present.

The mechanism for concentrating the discharge does not necessarily have to be formed on both the first electrode 1 and the second electrode 2. For example, if a protrusion is provided on the first electrode 1 in a certain discharge area to make the second electrode 2 linear, the discharge is concentrated on the side of the first electrode 1 and a triangular discharge shape is formed in this area.
If the electrode 2 has an arc shape, a fan-shaped discharge shape is obtained. Further, when forming a plurality of these, a protrusion may be provided only on the first electrode 1 in one region and a protrusion may be provided only on the second electrode 2 in another region. Further, it is not always necessary to form a plurality. Further, the roles of the two kinds of electrodes do not necessarily have 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 switched alternately. Further, the electrode pair formed by these electrodes may have a repeating structure. If such a repeating structure is adopted, the light emitting area can be freely set. Adjacent electrodes of the same type may be used as a common electrode.

By combining these configurations with the driving method of the first or second embodiment, high brightness and high luminous efficiency can be realized. That is, 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, and it is possible to realize high brightness and high luminous efficiency.

Next, the effect of forming a plurality of concentrated discharges by the mechanism and / or means as described above will be described. First, surface discharge light emission can be obtained by forming a plurality of concentrated discharges two-dimensionally. Furthermore, since the concentrated discharge locally has a very strong emission intensity, even if it is diffused and made two-dimensionally uniform, it is obtained from the beginning by a two-dimensionally uniform discharge and has a higher brightness than the emission. Become. Furthermore, while a two-dimensionally uniform discharge causes a current to flow over the entire surface, forming a plurality of concentrated discharges causes a local current flow, so the amount of current is not necessarily large over the entire surface. Not necessarily. Therefore, by optimizing, high brightness and high light emission efficiency can be realized.

Further, as means for obtaining two-dimensionally uniform light emission by concentrated discharge, for example, when designing this arrangement using a concentrated discharge as a light source, a region other than the light source causes leakage of light from a plurality of surrounding light sources. It may be arranged so that uniform light emission can be obtained as a whole by overlapping.
Further, the arrangement of the phosphors may be devised so that the light emission is uniform.

The formation of a plurality of concentrated discharges can be applied not only to two dimensions but also to three dimensions. When an experiment similar to that of the first embodiment is performed with such a configuration, a luminous efficiency of about 40 (lm / W) could be obtained without using mercury. From these results, by providing a mechanism for concentrating the discharge and driving by the driving method of the first or second embodiment, it is possible to realize a discharge light emitting device or the like with high brightness and high light emission efficiency. I understand.

[0080]

As is apparent from the embodiments of the present invention, in a method for driving a discharge light emitting device, characterized in that a potential difference is changed between electrodes to generate a gas discharge to cause light emission. It suppresses the latter half part of the positive discharge current, which has a low contribution to the brightness, by positively generating a positive discharge having the same polarity as the change in the potential difference and a negative discharge having a different polarity from the polarity. As a result, it is possible to save wasteful power and obtain high-efficiency discharge, and realize high brightness and high luminous efficiency.

As a result, it is possible to provide a discharge light emitting device, a display device, and the like, which have high luminance, high luminous efficiency, and can perform stable discharge.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an applied voltage waveform and a discharge current waveform according to the present invention.

FIG. 2 is a conceptual diagram of a discharge light emitting device used in Embodiment 1 of the present invention.

FIG. 3 is a conceptual diagram of an applied voltage waveform and a discharge current waveform according to the first embodiment.

FIG. 4 is a conceptual diagram of an applied voltage waveform and a discharge current waveform according to the second embodiment.

FIG. 5 is a conceptual diagram of the discharge light emitting device used in the third embodiment.

FIG. 6 is a conceptual diagram of a typical flat discharge lamp.

FIG. 7 is a conceptual diagram of an applied voltage waveform and a discharge current waveform of a typical flat discharge lamp.

[Explanation of symbols]

1st electrode 2 Second electrode 3rd electrode 11 First substrate 12 Second substrate 13 Dielectric layer 14 Protective film 15 Dielectric film 16 Reflective layer 17 Phosphor 18 partitions 20 spacers

Claims (18)

[Claims] 1. A driving method of a discharge forming device, wherein a change in potential difference is generated between electrodes to generate a gas discharge, wherein a positive discharge having the same polarity as the change in potential difference between electrodes and the polarity and polarity. A method of driving a discharge forming device, characterized in that negative discharges having different values are continuously generated. 2. A method of driving a discharge forming device, wherein a change in potential difference is generated between electrodes to generate a gas discharge, the positive polarity discharge having the same polarity as the change in potential difference between electrodes, and the polarity and polarity. A method for driving a discharge forming device, wherein negative discharges different from each other are continuously generated, and a positive discharge current is reduced by the generation of the negative discharge. 3. A driving method of a discharge forming device for generating a gas discharge by causing a change in a potential difference between electrodes, wherein a positive discharge having the same polarity as the change in the potential difference between the electrodes and the polarity and the polarity. The discharge forming device driving method is characterized in that negative discharges different from each other are continuously generated, and the positive discharge current is stopped by the generation of the negative discharge. 4. A continuous discharge is obtained by repeating a positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having the polarity different from the polarity in succession. The method of driving a discharge forming device according to claim 1. 5. A positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having the polarity different from the polarity are continuously generated, and a positive discharge current is reduced by the generation of the negative discharge. The method for driving a discharge forming device according to claim 2, wherein a continuous discharge is obtained by repeating the operation. 6. A positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having the polarity different from the polarity are continuously generated, and a positive discharge current is stopped by the generation of the negative discharge. 4. The method for driving a discharge forming device according to claim 3, wherein continuous discharge is obtained by repeating the operation. 7. A method of driving a discharge light-emitting device, which generates a gas discharge by causing a change in potential difference between electrodes to emit light, the positive polarity having the same polarity as the change in potential difference between electrodes, and the polarity. A method for driving a discharge light emitting device, characterized in that negative discharges having different polarities are continuously generated. 8. A method of driving a discharge light-emitting device, wherein a potential difference between electrodes is changed to generate a gas discharge to emit light, the positive polarity having the same polarity as the change in potential difference between the electrodes and the polarity. And a negative discharge having different polarities are continuously generated, and a positive discharge current is reduced by the generation of the negative discharge. 9. A method of driving a discharge light-emitting device, which generates a gas discharge by causing a change in potential difference between electrodes to emit light, the positive polarity having the same polarity as the change in potential difference between electrodes, and the polarity. And a negative discharge having a polarity different from that of the negative discharge, and a positive discharge current is stopped by the generation of the negative discharge. 10. A continuous light emission is obtained by repeating a positive discharge whose polarity is the same as the change of the potential difference between the electrodes and a negative discharge whose polarity is different from the polarity in succession. The method for driving a discharge forming device according to claim 7. 11. A positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having the different polarity from the polarity are continuously generated, and a positive discharge current is reduced by the generation of the negative discharge. 9. The method for driving a discharge forming device according to claim 8, wherein continuous light emission is obtained by repeating the operation. 12. A positive discharge having the same polarity as the change in the potential difference between the electrodes and a negative discharge having a polarity different from the polarity are continuously generated, and a positive discharge current is stopped by the generation of the negative discharge. 10. The method for driving a discharge forming device according to claim 9, wherein continuous light emission is obtained by repeating the operation. 13. A discharge forming device, wherein a discharge is formed by the driving method according to claim 1. 14. A mechanism for concentrating a discharge,
A discharge forming device, wherein a discharge is formed by the driving method according to any one of claims 1 to 3. 15. A discharge light emitting device, which emits light by the driving method according to claim 7. 16. A mechanism for concentrating a discharge,
A discharge light emitting device, which emits light by the driving method according to claim 7. 17. An illumination device configured to illuminate an object to be illuminated using the discharge light emitting device according to claim 15. 18. A display apparatus using the driving method according to claim 7, the discharge light emitting device according to claim 15 or 16, or the lighting device according to claim 17.