JPH056147A - Drive method for gas discharge light emitting device - Google Patents

Abstract

PURPOSE:To reduce uneven brightness of a display cell and damage of cathode due to sputter, in a plasma display panel. CONSTITUTION:In a term S in which a maintaining pulse Psp is applied, potential difference between an anode and a cathode is gradually increased from the potential difference (a) smaller than the discharge maintaining minimum voltage to the potential difference (b) larger than the discharge maintaining minimum voltage and smaller than the discharge beginning minimum voltage. The potential difference between the anode and the cathode in the term S is set as (a) at building-up of the maintaining pulse Psp, hereafter gradually increased from (a) to (b) while consuming optional and appropriate time. Hereby, the discharge current flowing in a display cell is increased gently and smoothly so as to attain the purpose, without forming actually large peak or causing violent vibration even at increasing the potential difference (b) for increasing light emitting strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a gas discharge light emitting device such as a direct current type gas discharge display panel (so-called DC-PDP) or an optical print head using gas discharge light emission as a light source. In particular, it relates to a memory type driving method.

[0002]

2. Description of the Related Art In recent years, panel displays have been actively developed and put to practical use, and small televisions have been realized by liquid crystal or flat CRT in the field of television display, but large-scale panel displays have not been put to practical use. First, introduction of a memory function into a gas discharge display panel has been promoted toward the practical use of a large-sized panel (Reference I: Journal of the Television Society, vol. 40, No 10 (1986) p953.
~ 960). Hereinafter, the structure and driving method of the gas discharge display panel proposed in the above document will be briefly described with reference to FIG.

7 (A) and 7 (B) are perspective views showing the structure of the gas discharge panel proposed in the above document, where (A) is the structure on the front substrate side of the panel and (B) is the structure. The structure on the rear substrate side is shown.

As shown in FIG. 7B, in this panel, a predetermined number of cathodes 12 are arranged in parallel on a back substrate 10, and display cells 16 and auxiliary cells 14 are formed on the cathodes 12. A bank (partition) 18 is provided for this purpose.

Further, as shown in FIG. 7A, a display anode 22 is formed on a translucent front substrate 20 (for example, a glass substrate).
Further, the auxiliary anode 24 is arranged in parallel, and the phosphor 26 is applied to the position facing the display cell 16 so as to expose the display anode 22.

Then, with the rear substrate 10 and the front substrate 20 facing each other with their electrode forming surfaces facing each other, and with the substrates being aligned so that the cathode 12 and the anodes 22 and 24 intersect in a plan view, the outer peripheries of these substrates are aligned. The parts are sealed via an airtight sealing part (not shown), and the gas medium for discharge is sealed in the sealed region between the substrates. The display cell 16 includes a cathode 12 and a display anode 22.
, And the auxiliary cell 14 is formed at the intersection of the cathode 12 and the auxiliary anode 24.

FIG. 8 is a diagram schematically showing a wiring structure for a conventional memory type driving method, and FIG. 9 is a time chart for explaining the conventional memory type driving method.

In FIG. 8, for simplification of description, the gas discharge panel 28 having the above-described structure is provided with the display anodes 221 to 224.
And the cathodes 121 to 124, and therefore has display cells 16 _MN arranged in 4 rows and 4 columns (reference numeral 16 _MN represents a display cell in the Mth row and the Nth column). The display anode 22
1, the auxiliary anode 241 between the first and the second 222, and the display anode 22.
The auxiliary anode 242 is disposed between the electrodes 3 and 224.

In the conventional driving method, in order to drive the panel 28, each of the display anodes 221 to 224 is connected to the sustain pulse generating circuit 32 through the diode D ₂ and also through the diode D ₁ . Write pulse generation circuit 3
Connect with 0. Further, each of the cathodes 121 to 124 is connected to the scan pulse and erase pulse generation circuit 34, and the auxiliary anodes 241 and 242 are connected to the power source 38 via the resistor 36.
Connect with. The diodes D ₁ and D ₂ form an adder for mixing the write pulse and the sustain pulse.

Next, a conventional driving method will be described with reference to FIG.

In driving the panel 28, as shown in FIG. 9, the scanning pulse P _K (pulse width τ _K , amplitude V _K )
The cathodes 121, 1 of the first, second, third and fourth rows
22, 123 and 124 are sequentially applied to the display anodes 221 to 224 with a period T while the sustain pulse P _sp (pulse width τ _sp , amplitude V _sp ) is applied to each of the display anodes 221 to 224. The scan pulse P _K and the sustain pulse P _sp are applied so that their timings do not overlap. For example, the scan pulse P _K is applied to the cathode 122 during the period from time t _{1 to} t ₂ , but the sustain pulse P _sp is applied to the display anodes 221 to 22 1. Therefore, the discharge of the display cell does not start due to the fact that the scan pulse P _K and the sustain pulse P _sp overlap with each other.

Further, a constant positive potential is constantly applied to the auxiliary anodes 241 and 242 by the power source 38. Therefore, the auxiliary cells of the cathode to which the scanning pulse P _K is applied are sequentially discharged, for example, at time t _1. in the period ~t ₂ scan pulse P
_{Since K} is applied to the cathode 122 on the second row, a discharge current flows in the auxiliary cells on the second row.

When the display cell 16 _MN is written (discharge is formed), the write pulse P _W (pulse width τ _W , amplitude V) is generated at substantially the same timing as the discharge of the auxiliary cell on the M-th row.
_W ) is applied to the anode 22 _N in the Nth row. At this time, the charged particles from the M-th row of the auxiliary cell discharges in the display cell 16 _MN vicinity, such metastable particles are diffused into the display cell 16 _MN.
As a result, the discharge delay time of the cell 16 _MN is shortened, so that the variation in the discharge delay of the display cell can be greatly reduced. Therefore, the pulse width τ _W is narrow and the amplitude V _{W is}
Write pulse P _W and scan pulse P _K
A discharge can be generated in the display cell 16 _{MN due} to the potential difference. For example, when writing of the display cell 16 _22, the time t ₁ the second row of auxiliary cell is discharging ~t ₂
The write pulse P _W during the period of
To generate a discharge in the display cell 16 ₂₂ .

By the way, the gas discharge has a characteristic that the charged particles and the like generated by the discharge gradually decrease after the discharge is stopped, and the discharge easily occurs again in the presence of the charged particles and the like. A driving method of a method of using the memory is called a memory driving method.

[0015] In this conventional driving method method, as the sustain pulse P _sp is applied within the re-discharge state of easily after discharge by a write pulse P _W is stopped, set the cycle T of the sustain pulse P _sp Therefore, write pulse P _W
After the discharge is formed in the discharge cell 16 _MN by, for example, in the display cell 16 ₂₂ in the period from time t _{3 to} t ₄ after the discharge is formed, even if the write pulse P _W is not applied, it is pulsed by the sustain pulse P _sp . Discharge can be maintained (intermittently). Ultraviolet rays generated by the discharge reach the phosphor 26 and are absorbed, and the phosphor 26 emits light.

The emission intensity can be improved by narrowing the period T and increasing the number of discharges generated per unit time in the discharge cell, and thus sufficient display brightness can be obtained even when the number of scanning lines is as large as 1000 lines. it can.

FIG. 10 is a diagram showing in more detail the relationship between the discharge current flowing in the display cell and the voltage applied to the anode in the conventional driving method. In FIG. 10, the vertical axis shows the discharge current (cell current) flowing in the display cell and the horizontal axis shows the waveform of the cell current with time, and the vertical axis shows the voltage applied to the anode (anode applied voltage) and the horizontal axis. Along the axis, the waveform of the voltage applied to the anode is shown.

[0018] As shown in FIG. 10, the cell current that flows in response to the sustain pulse P _SP is towards the trailing edge of the sustain pulse P _SP after forming a large peak at approximately the leading edge of the sustain pulse P _SP attenuation Vibrate.

[0019] To stop the discharge in the display cells 16 _MN, the cathode 12 by raising force the potential of the cathode 12 _M applies the erase pulse P _E to the cathode 12 _M of the M-th row
The potential difference between _M and the anode 22 _N is reduced, for example, at time t
_The erase pulse P _E is applied only for a period of _{5 to} t _{6 so that} the discharge by the sustain pulse P _sp does not occur more than once, the charged particles are reduced or eliminated, and the sustain pulse P _sp is applied. Also, prevent re-discharge in the display cell 16 _MN .

[0020] Incidentally, the cathode in the conventional driving method, which applies the amplitude (scan voltage) V _K of the scanning pulse P _K example -220V, the cathode 12 when not applied to the scan pulse P _K and the erase pulse P _E For example, the pre-bias voltage is -80
V, the amplitude (sustain voltage) V _SP of the sustain pulse P _{sp is} , for example, 1
The anode pre-bias voltage applied to the anode 22 is 40 V, for example, and 0 V is applied when the sustain pulse P _sp and the write pulse P _W are not applied.

[0021]

In the above-mentioned conventional driving method, when it is desired to obtain a larger gradation, the light emission intensity of the display cell may be increased, but the number of discharges of the display cell per unit time is increased. Since there is a limit to the increase of the emission voltage, the emission voltage is generally increased by increasing the sustain voltage V _SP .

[0022] However maintain Increasing the voltage V _SP, sustain pulses P damping vibrations of a cell current corresponding to the _SP peak value of the cell current amplitude occurs at the leading edge portion of the increases and in particular sustain pulses P _SP (see FIG. 10) However, there is a problem in that display uneven brightness and uneven color are generated. Further, as the amplitude of the damping oscillation of the cell current becomes large, there is a problem that the cathode sputtering becomes violent and the panel life becomes short.

An object of the present invention is to provide a method of driving a gas discharge light emitting device which can gently increase the cell current even if the sustain voltage V _SP is increased in order to solve the above-mentioned conventional problems. It is in.

[0024]

In order to achieve this object, a method of driving a gas discharge light emitting device according to the present invention is arranged such that an anode and a cathode are opposed to each other with a discharge gas interposed, and an anode and a cathode are provided in a write discharge period. A potential difference equal to or higher than the discharge start minimum voltage V _{s is} applied between the cathodes to form discharge, and in the discharge erasing period,
The discharge maintaining minimum voltage V _O or less is applied between the anode and the cathode to erase the discharge, and in the sustain discharging period provided between the address discharge period and the discharge erasing period, the discharge maintaining minimum voltage is generated between the anode and the cathode. In a method of driving a gas discharge light emitting device that forms a discharge by applying a potential difference larger than V _{O and} smaller than a discharge start minimum voltage V _s , in a sustain discharge period provided between an address discharge period and a discharge erase period, an anode is used. And a potential difference between the cathodes is gradually increased from a potential difference equal to or lower than the discharge maintaining minimum voltage V _{O to} a potential difference larger than the discharge maintaining minimum voltage V _{O and} smaller than the discharge starting minimum voltage V _s to form a discharge. And

[0025]

According to the driving method of the present invention, in the sustain discharge period provided between the address discharge period and the discharge erase period, the potential difference between the anode and the cathode is equal to or lower than the discharge sustaining minimum voltage V _O (potential difference at this time). From the potential difference a) to a potential difference larger than the discharge sustaining minimum voltage V _{O and} smaller than the discharge starting minimum voltage V _s (the potential difference at this time is represented as the potential difference b) to form discharge. In particular, it is preferable to apply a potential difference a between the anode and the cathode at the start of the sustain discharge period.

In order to increase the intensity of light emitted by the discharge formed during the sustain discharge period, the potential difference b may be increased to increase the discharge current flowing during the sustain discharge period.

However, when the potential difference b is increased until a desired emission intensity is obtained and the potential difference a is rapidly changed to the potential difference b in an infinitely small period, the discharge current forms a large peak and then attenuates while oscillating. , The discharge current changes drastically. At this time, as the potential difference b is increased in order to increase the emission intensity, the size of these peaks and the amplitude of the damping vibration are increased, and the uneven brightness and the uneven color of the emitted light are increased.

However, as described above, by gradually increasing the potential difference between the anode and the cathode from the potential difference a to the potential difference b while spending an arbitrary and suitable time, the discharge current is increased even if the potential difference b is increased in order to increase the emission intensity. Can be slowly increased without forming a substantially large peak or damped oscillation, and therefore the discharge current can be gently increased.

[0029]

EXAMPLES Hereinafter, one example of the present invention will be described. In order to deepen the understanding of this example, a hysteresis characteristic regarding gas discharge will be described before the description of the example.
Next, the driving principle of this embodiment will be described.

FIG. 6 is a diagram showing a voltage-current hysteresis characteristic of a discharge cell (display cell) included in the gas discharge light emitting device. In FIG. 6, the horizontal axis represents the potential difference between the anode and the cathode in the gas discharge light emitting device, and The vertical axis represents the discharge current between the anode and the cathode.

The voltage-current hysteresis of the discharge cell generally has the characteristics shown in FIG. That is, when the potential difference between the cathode and the anode (hereinafter, also simply referred to as the potential difference) is gradually increased from 0 V, the cathode and the anode are kept until the potential difference reaches the discharge start minimum voltage V _S (for example, 220 V) as shown in the path. The discharge current does not flow between them, but as shown in the path, when the potential difference becomes the voltage V _S , the discharge current flows and the discharge starts between the cathode and the anode. And as shown in the path,
When the potential difference is further increased after the start of discharge, the discharge current linearly increases at a substantially constant rate. Then, when the discharge current increases to some extent and the potential difference decreases,
As shown in the path, the discharge current decreases linearly at the same constant rate as when it increases. The potential difference of the discharge is the voltage V
Even if it becomes _S , it does not stop, and the discharge current decreases until it reaches the minimum discharge maintaining voltage V ₀ (for example, 210 V). When the potential difference becomes the voltage V ₀ , the discharge current becomes 0 and the discharge stops. . After the discharge is stopped, as indicated by the path, the discharge current does not flow with a potential difference smaller than the voltage V ₀ .

The driving method of this embodiment utilizes the above-mentioned hysteresis characteristics to discharge (emit) the discharge cell.
Is to control.

That is, in this embodiment, a discharge is formed by applying a potential difference equal to or higher than the discharge start minimum voltage V _S (hereinafter, start voltage V _S ) between the anode and the cathode in the address discharge period, and in the discharge erase period, the anode and the cathode. The discharge is erased by applying a potential difference equal to or lower than the discharge sustaining minimum voltage V ₀ (hereinafter, sustain voltage V ₀ ) in between. Then, in the sustain discharge period provided between the address discharge period and the discharge erase period, the potential difference between the anode and the cathode is equal to or lower than the sustain voltage V _O (the potential difference at this time is represented as the potential difference a), and then the sustain voltage V _O Is gradually changed to a potential difference larger than the start voltage V _s and smaller than the start voltage V _s (the potential difference at this time is represented as a potential difference b). Particularly preferably, a potential difference a is applied between the anode and the cathode at the start of the sustain discharge period. The emission intensity of the discharge formed during the sustain discharge period becomes stronger as the potential difference b is increased. Therefore, the desired emission intensity can be obtained by setting the potential difference b to an arbitrary and suitable size.

As described in the section (Operation) above, the potential difference between the anode and the cathode is gradually increased from the potential difference a to the potential difference b while spending an arbitrary suitable time,
The discharge current gradually increases without forming a substantially large peak or vibrating violently even if the potential difference b is increased to increase the emission intensity, and thus the discharge current can be gently increased. As a result, it is possible to reduce uneven brightness and uneven color of light emission. The potential difference between the anode and the cathode may be changed stepwise in a stepwise manner from the potential difference a to the potential difference b, or may be smoothly and continuously changed.

[0035] According to the experiments of the inventors of this application, the potential difference a from smaller potential than larger than the sustain voltage V _O potential difference b between the potential difference b increased to the the anode instead and cathode until until the potential difference b When gradually changing, it was not always possible to effectively prevent uneven brightness and uneven color.

Further, in this embodiment, during the rest period excluding the sustain discharge period from the address discharge period to the discharge erase period, the potential difference between the anode and the cathode is about the same as the sustain voltage V _O. A potential difference smaller than the sustain voltage V _O is given.

Next, an embodiment of the present invention will be described.

FIG. 4 is a diagram schematically showing a wiring structure for the driving method of this embodiment. Incidentally, in FIG. 4, constituent elements corresponding to those of the related art are denoted by the same reference numerals,
A detailed description of the same points as the conventional one will be omitted.

The wiring structure shown in FIG. 4 has cathodes 121 to 12
4 is connected to the pulse generating circuit 40, respectively, and is the same as the conventional one shown in FIG. The pulse generation circuit 40 generates an erase pulse P _E and a scan pulse P _K , and an adjustment pulse P _B for adjusting the potential difference between the cathode and the anode during the sustain discharge period. Adjustment pulse P
_B is, for example, three pulses P _B1 of different amplitudes,
It is composed of P _B2 and P _B3 (see FIG. 2A described later).

Hereinafter, the case where the display cell 16 ₁₁ is caused to emit light by discharge will be described as an example.

2 and 3 are time charts for explaining the driving method according to the embodiment of the present invention. 2A,
(B) and (C) are cathodes 121, 122 and 1 respectively.
The voltage waveforms applied to No. 23 are shown. In these figures, the voltage applied to the cathode is plotted on the vertical axis and the time on the horizontal axis. Further, FIG. 3A shows a voltage waveform applied to the anode 121,
3B shows voltage waveforms applied to the anodes 122 to 124. In these figures, the vertical axis shows the voltage applied to the anode and the horizontal axis shows time.

In this embodiment, as shown in FIG.
Row, second row, third row and fourth row of cathodes 121, 122,
While the scan pulse P _K is applied to 123 and 124 in time sequence, the sustain pulse P _sp is applied to each of the display anodes 221 to 224 at the cycle T as shown in FIG. At this time, the scan pulse P _K and the sustain pulse P _sp are set so that the application periods of these pulses do not overlap with each other, and therefore the writing discharge does not occur due to the overlap of the application periods of these pulses P _K and P _sp .

A constant positive potential is always applied to the auxiliary anodes 241 and 242. As a result, auxiliary discharge is sequentially generated in the auxiliary cell 14 of the cathode to which the scanning pulse P _K is applied.

FIG. 1 is another time chart for explaining the driving method according to the embodiment of the present invention, in which display cells 16 _MN in the M-th row and the N-th column, for example, display cells 16 ₁₁ attempt to generate discharge. The waveforms of the voltages applied to the anode and cathode of the cell 16 ₁₁ in this case are shown. In the figure, the vertical axis represents voltage and the horizontal axis represents time, and the waveform of the voltage applied to the anode is indicated by reference symbol a and the waveform of the voltage applied to the cathode is indicated by reference symbol b.

In FIG. 1, for example, the minimum discharge maintaining voltage V _O is V _O = 200 V and the minimum discharge starting voltage V _s.
Is set to V _s = 320V, and the voltage V _sp of the sustain pulse P _sp is set to V
and _sp = 140V, the voltage V _W of the write pulse P _W V
_W = 100 V, and the anode pre-bias voltage V _BA is V _BA =
0 V, the erase pulse voltage V _E and the pulse P _B1 voltage V _B1 are V _E = V _B1 = 0 V, and the cathode pre-bias voltage V
The voltage V _B2 of the _BC and the pulse P _B2 and V _BC = V _B2 = -60 V, the voltage V _B3 of the pulse P _B3 V _B3 = -80V, and the voltage V _K of the scanning pulse P _K and V _K = -220V did. In the following description, the potential difference between the anode and the cathode represents the absolute value of the difference between the voltage applied to the anode and the voltage applied to the cathode.

[0046] If the discharging display cells 16 ₁₁ to perform a light-emitting display in display cell 16 ₁₁ As shown in FIG. 1, the first
The write pulse P _W is applied to the anode 221 of the first column in a period substantially the same as the application period of the scan pulse P _K for the row. For example, time T ₂ > time T _{2 (−)} , time T _{1 to} T ₂ is the application period of the scan pulse P _K applied to the cathode 121, and time T _{1 to} T _{2 (−)} is applied to the anode 221. The write pulse P _W is applied. In this example, the time T _{1 to} T _{2 (−),} which is the application period of the scan pulse P _K , is the writing discharge period.

In the write discharge period T _{1 to} T _{2 (1)} , the potential difference between the cathode 121 and the anode 221 becomes equal to or higher than the discharge start minimum voltage V _s (start voltage V _s ), so that the display cell 16 ₁₁
Writing discharge is generated in the region where the cathode 121 and the anode 221 face each other. Note that no write discharge occurs between the anode and the cathode to which the write pulse P _W is not applied during the scan pulse application period. The write pulse P _W first row auxiliary cell to approximately the same period as the period for applying the 14 (cathode 12
1 and the auxiliary anode 241 face each other).

Next, the first sustain pulse P _sp after the start of the write discharge is applied to the anodes 221 of the first row immediately after the write pulse P _W is applied, and the second sustain pulse P _sp after the write discharge is started.
Sustain discharge P _sp times onward, the first round of the sustain pulse P _sp
The voltage is applied to the anodes 221 in the first row in sequence at intervals of from T to T. From a write discharge period to a discharge erase period described later (between application of the write pulse P _W and application of an erase pulse P _E described later), for example, the first time after the start of discharge. The three sustain pulses P _sp from the first to the third time are applied. Application period of each sustain pulse P _sp , for example, time T _{2 to} T ₃ , time T _{4 to} T ₅ , and time T ₆
Up to T ₇ are sustain discharge periods.

In this example, the sustain pulse P _sp for the first time is continuously applied to the write pulse P _W. However, the discharge pulse is easily generated in the display cell 16 ₁₁ after the write discharge is formed, and the first sustain pulse P _sp is applied for the first time. If the sustain pulse P _sp is applied,
It is not always necessary to apply the first sustain pulse P _sp in succession to the write pulse P _W.

Then, in the sustain discharge period provided between the address discharge period and the discharge erase period, the adjustment pulse P _B is applied to the cathode 121 during the same period as the sustain discharge period. In this sustain discharge period, the sustain pulse P _sp and the adjustment pulse P _B are applied to change the potential difference between the cathode 121 and the anode 221 from the potential difference equal to or lower than the discharge sustain minimum voltage V _O (sustain voltage V _O ). Start voltage V _s greater than _O
Display cell 1 by gradually increasing the potential difference to a smaller value.
A discharge at 6 ₁₁ is formed.

In this example, the adjustment pulse P _B is an arbitrary suitable number of a plurality of component pulses, for example, three pulses P _B1 , P _B2.
And P _B3 are formed by sequentially time-sequentially, and the amplitudes of these pulses P _B1 , P _B2, and P _B3 sequentially increase stepwise. Then, when the sustain pulse P _sp rises, the first pulse P _B1 is applied.

When the pulse widths of the pulses P _B1 , P _B2 and P _B3 are expressed as τ _B1 , τ _B2 and τ _B3 , respectively, the pulse P is different from the first sustain pulse P _sp after the start of the write discharge. The application periods of _B1 , P _B2 and P _B3 are respectively from time T _{2 (-)} to
T _{2 (-)} + τ _B1 (however, (T _{2 (-)} + τ _B1 )> T ₂ ＞
T _{2 (-)} ), time T _{2 (-) to} T _{2 (-)} + τ _B1 + τ _B2 , and time T _{2 (-) to} T _{2 (-)} + τ _B1 + τ _B2 + τ _B3 (= T ₃ ). .
In the application period of the pulse P _B1 , the cathode 121 and the anode 22
The potential difference between 1 and the potential difference x is smaller than the sustain voltage V _O, for example, the potential difference between the cathode 121 and the anode 221 when an erasing pulse P _E described later is applied to the cathode 121 is smaller than the potential difference x = 0V. , The potential difference between the cathode 121 and the anode 221 during the application period of the pulse P _B2 is a potential difference y close to the sustain voltage V _O, for example, the sustain voltage V 0.
Positive potential difference y = V _O = 200 V, which is slightly larger than _O , and the potential difference between the cathode 121 and the anode 221 during the application period of the pulse P _B3 is a potential difference z smaller than the start voltage V _s, for example, z = 220 V. Is.

The difference between the times T ₂ and T _{2 (-)} and the pulse width τ _B1
By setting + τ _B2 + τ _B3 and the potential differences x, y, and z to any suitable values, the sustain discharge current flowing through the display cell 16 ₁₁ during the first sustain discharge period T _{2 to} T ₃ after the start of the sustain discharge is moderated. Can be increased to Sustain discharge period T
By gradually increasing the discharge current in the course of increasing the potential difference between the cathode 121 and anode 221 in ₂ through T _3, it is possible to increase the luminous intensity while reducing the decrease of the luminance unevenness and color unevenness. In particular, by applying the pulse P _B1 at the rise of the sustain pulse P _sp , it is possible to prevent the sustain discharge current flowing in the display cell 16 _{11 from} having a large peak at the rise of the sustain pulse P _sp .

Similarly, for the second sustain pulse P _sp after the start of the write discharge, the pulses P _B1 , P _B2 and P _{B3 are generated.}
The application period of time is from time T _{4 (-) to} T _{4 (-)} + τ _B1 (however, (T _{4 (-)} + τ _B1 )> T ₄ > T _{4 (-)} ), time T _{4 (-)}
T _{4 (-)} + τ _B1 + τ _B2 , and time T _{4 (-) to} T _{4 (-)} + τ _B1 +
τ _B2 + τ _B3 (= T ₅ ), and for the third sustain pulse P _sp after the start of the write discharge, the pulse P _B1 ,
The application period of P _B2 and P _B3 is from time T _{6 (-) to} T _{6 (-), respectively.}
+ Τ _B1 (however, (T _{6 (-)} + τ _B1 )> T ₆ > T _{6 (-)} ), time T _{6 (-) to} T _{6 (-)} + τ _B1 + τ _B2 , and time T _{6 (-)} to T
_{6 (-)} + τ _B1 + τ _B2 + τ _B3 (= T ₇ ). These second
Also in the case of the sustain pulse P _sp for the first time and the third time, the same operational effect as in the case of the sustain pulse P _sp for the first time can be obtained.

Since the write discharge is formed in the display cell 16 _{11 which} is desired to emit light, even if the potential difference between the anode and the cathode is set smaller than the starting voltage V _s , the potential difference of the sustain voltage V _O or more is applied to the anode and the cathode. A discharge can be formed by applying it between the cathodes. In a display cell that does not want to emit light, write discharge is not formed, so that the potential difference between the anode and the cathode is set to the start voltage V
By making it smaller than _s, it is possible to prevent the formation of discharge and prevent erroneous discharge.

After the write discharge period of the display cell 16 ₁₁
After applying a predetermined number, for example, three sustain pulses P _sp to the cathode 121, an erase pulse P _E is applied to the cathode 121 to erase the discharge in the display cell 16 ₁₁ . The application period T _{E1 to} T _{E2 of the} erase pulse P _E is the discharge erase period.

In the erase period T _{E1 to} T _E2 , the erase pulse P _E
The potential difference between the cathode 121 and the anode 221 becomes smaller than the sustain voltage V _O by the application of the voltage.
Even if the sustain pulse P _sp is applied to No. 1, discharge does not occur in the display cell 16 ₁₁ . As long as the discharge in the display cell 16 ₁₁ can be erased, the potential difference between the anode and the cathode may be continuously made smaller than the sustain voltage V ₀ , or intermittently made smaller than the sustain voltage. good. After the discharge of the display cell 16 ₁₁ is erased, the scan pulse P _K and the write pulse P _W are applied to the cathode 121 and the anode 221, and the potential difference between these electrodes must be equal to or higher than the start voltage V _s.
No discharge occurs at ₁₁ .

FIG. 6 is a diagram schematically showing the relationship between the discharge current flowing in the display cell 16 ₁₁ and the voltage applied to the anode in the driving method of this embodiment. In FIG. 6, the discharge current (cell current) flowing in the display cell 16 ₁₁ is plotted on the ordinate and the time is plotted on the abscissa to show the waveform of the cell current of the display cell 16 ₁₁ and the ordinate is applied to the anode. The voltage (the voltage applied to the anode) and the horizontal axis show the waveform of the voltage applied to the anode with the time taken.

As shown in FIG. 6, the cell current flowing in the display cell 16 ₁₁ does not form a large peak in the portion corresponding to the leading edge of the sustain pulse P _SP , and the leading edge to the trailing edge of the sustain pulse P _sp. Gradually increase towards. As a result, the display cell 16
₁₁ uneven brightness and uneven color can be reduced.

The present invention is not limited to the above-mentioned embodiments, and therefore, the wiring structure or the driving circuit for realizing the driving method of the present invention, the signal waveform, the application timing of each signal, and the pulse width. The voltage values such as time and pulse amplitude, numerical conditions, and the like can be arbitrarily changed.

The present invention can also be applied to various gas discharge light emitting devices such as display devices, optical heads and the like.

[0062]

As is apparent from the above description, according to the driving method of the gas discharge light emitting device of the present invention, between the anode and the cathode in the sustain discharge period provided between the address discharge period and the discharge erase period. The potential difference of (1) is gradually increased from a potential difference (potential difference a) equal to or lower than the discharge maintaining minimum voltage V _{O to} a potential difference (potential difference b) larger than the discharge maintaining minimum voltage V _{O and} smaller than the discharge starting minimum voltage V _s. Form.

Therefore, the potential difference between the anode and the cathode is defined as the potential difference a.
From the potential difference b in order to increase the emission intensity by gradually increasing it while spending any suitable time.
Even if the value is increased, the discharge current gradually increases without forming a substantially large peak or damped oscillation, and the discharge current can be gently increased.

As a result, it is possible to reduce the uneven brightness and the uneven color of light emission. Further, the discharge current does not substantially form a large peak, and as a result, damage due to sputtering of the cathode is reduced.

[Brief description of drawings]

FIG. 1 is a time chart used for explaining an embodiment of a driving method of the present invention.

2 (A), (B) and (C) are time charts for explaining a driving method of the present invention.

3A and 3B are time charts for explaining a driving method of the present invention.

FIG. 4 is a diagram showing a wiring structure for an embodiment of a driving method of the present invention.

FIG. 5 is a diagram showing the relationship between the discharge current and the voltage applied to the anode in the driving method according to the embodiment of the present invention.

FIG. 6 is a diagram showing general characteristics of voltage-current hysteresis in gas discharge.

7A and 7B are perspective views schematically showing the structure of a gas discharge display panel as an example of the gas discharge light emitting device.

FIG. 8 is a diagram showing a wiring structure for a conventional driving method.

FIG. 9 is a time chart used for explaining a conventional driving method.

FIG. 10 is a diagram showing a relationship between a discharge current and a voltage applied to an anode in a conventional driving method.

[Explanation of symbols]

P _W : Write pulse P _sp : Sustain pulse P _K : Scan pulse P _E : Erase pulse P _B , P _B1 , P _B2 , P _B3 : Adjustment pulse

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Toyama             1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric             Industry Co., Ltd.

Claims (4)

[Claims] 1. An anode and a cathode are opposed to each other with a discharge gas interposed therebetween, and during the address discharge period, between the anode and the cathode,
A potential difference of not less than the minimum discharge start voltage V _{s is} applied to form a discharge, and a potential difference of not more than the minimum discharge sustaining voltage V _{O is} applied between the anode and the cathode in the discharge erasing period to erase the discharge and the address discharge period. In the sustain discharge period provided between the discharge erasing period and the discharge erasing period, the discharge maintaining minimum voltage V _O
In the driving method of the gas discharge light emitting device, wherein a discharge is formed by applying a potential difference that is larger than the discharge start minimum voltage V _s and is smaller than the discharge start minimum voltage V _s , in the sustain discharge period provided between the writing discharge period and the discharge erasing period, The discharge is formed by gradually increasing the potential difference between the cathodes from a potential difference that is equal to or lower than the discharge maintaining minimum voltage V _{O to} a potential difference that is higher than the discharge maintaining minimum voltage V _{O and} smaller than the discharge starting minimum voltage V _s. Method for driving a gas discharge light emitting device. 2. A potential difference smaller than the minimum discharge sustaining voltage V _O is applied between the anode and the cathode at the start of the sustaining discharge period provided between the address discharge period and the discharge erasing period. A method of driving the gas discharge light emitting device according to. The method according to claim 3 sustain discharge period provided between the address discharge period and a discharge erase period, between the anode and the cathode, sustaining minimum voltage V _O smaller potential difference than sustaining minimum voltage V of the _O near The gas discharge light emission according to claim 1, wherein a potential difference of a magnitude and a potential difference larger than the discharge sustaining minimum voltage V _{O and} smaller than the discharge starting minimum voltage V _s are sequentially applied to form discharge. Device driving method. 4. The minimum sustaining voltage VO between the sustaining minimum voltage V _{O and the} minimum sustaining voltage V _O between the anode and the cathode during the rest of the period from the address discharge period to the discharge erasing period except the sustain discharge period. The method for driving a gas discharge light emitting device according to claim 1, wherein a potential difference smaller than V _O is applied.