JP2720801B2 - Plasma display panel driving method and plasma display panel driving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel driving method and a plasma display panel driving apparatus, and more particularly to a dot matrix type plasma display panel driving method and a plasma display panel driving apparatus.

[0002]

2. Description of the Related Art A plasma display panel (PDP) of this type is used for personal computers and office workstations, which have remarkably progressed in recent years, and wall-mounted televisions, which are expected to develop in the future.

[0003] In PDPs, depending on the operation method, the electrodes are covered with a dielectric material and are not exposed to a discharge gas.
There are a DC type and a DC type in which an electrode is directly exposed to a discharge gas and discharge occurs only during a period when a voltage is applied. In the AC type, the discharge cell itself has a memory function due to the action of the dielectric.

FIGS. 6 (A) and 6 (B) which show an example of the configuration of a general AC type PDP in a plan view and a cross-sectional view taken along line xx ', respectively, show a PDP 1 shown in FIG.
0 denotes a first insulating substrate 11 made of glass, a second insulating substrate 12 also made of glass, a sustain electrode 13a, a scan electrode 13b, a sustain electrode 13a and a scan electrode 13b.
A metal electrode 13c for supplying a sufficient current to the column electrode 14, a column electrode 14, a discharge gas space 15 filled with a discharge gas such as He or Xe, a partition wall 16 for securing the discharge gas space 15 and separating pixels. A phosphor 17 for converting ultraviolet light generated by the discharge of the discharge gas into visible light, and a sustain electrode 1
An insulating layer 18a covering the 3a and the scanning electrodes 13b, an insulating layer 18b covering the column electrodes 14, and a protective layer 19 made of MgO or the like for protecting the insulating layer 18a from electric discharge.

Referring to FIG. 7, which is a plan view showing details of the configuration of the electrodes of the PDP 10, a first insulating substrate 11 and a second insulating substrate 12 are adhered to each other. provided, the sustain electrode 13a are electrodes C _1, C _2, ..., consist C _m, the scanning electrodes 13b are electrodes S _1, S _2, ..., consist S _m, the column electrodes 14 are electrodes D _1, D _2, ... , consisting of D _n.

In FIG. 6A, a pixel 20 which is a section surrounded by vertical and horizontal partitions is a scanning electrode S in FIG.
_i (i = 1, 2,..., m) and the column electrode D _j (j = 1, 2, 2)
.., N) are indicated by a _ij as pixels at intersections. Further FIG.
If the phosphor 17 of (B) is painted in three colors for each pixel, a PDP for color display can be obtained.

As a driving method when a gradation display including a halftone such as a television image is performed by a PDP of this type, a driving method described in Kenichi Owaki et al., Plasma Display Panel, Kyoritsu Shuppan, 1983, pp. 158-161. In-field time division method, that is, a subfield method. In this method, one screen display period (one field) is time-divided into a plurality of subfields weighted so that the light emission luminance becomes 1, 2, 4, 8,... What you get.

Referring to FIG. 8, which is an explanatory view of gradation display by the subfield method, a case where gradation display is performed using this PDP will be described. One field is divided into k subfields (hereinafter, SF). Dividing (here k = 8) and weighting the light emission luminance of each pixel in the n-th SFn (here SF1 to SF8) by 2 ^kn (SF1 is 2 ⁷ = 1)
28, SF2 has a weight of 2 ⁶ = 64,..., SF8 has a weight of 2 ⁰ = 1), and the luminance L can be expressed as follows.

[0009]

(Equation 1)

A _n is a variable having a value of 1 or 0.
If k = 1, two-gradation display of luminance L ₀ at the time of selection (a ₁ = 1) and luminance ₀ at the time of non-selection (a ₁ = 0) is possible. In this example, k = 8. A display of 2 ⁸ = 256 gradations is possible. For example, if a ₁ = 1 and a _{2 to} a ₈ = 0, then 12
This is the eighth gradation level.

Referring to Figure 9 showing an example of driving voltage waveforms and light emission waveform in one SF for this PDP, waveform (A) is maintained electrodes C _1, C _2, ..., preliminary discharge to be applied to each of the C _m The voltage waveforms and waveforms (B), (C), and (D) of pulse PP and sustain pulse H1 are erase pulse E and predischarge erase pulse PE applied to scan electrodes S ₁ , S ₂ , and _Sm , respectively. , Scan pulse PS and sustain pulse H2, waveforms (E) and (F) are the voltage waveforms of data pulse D applied to column electrodes D ₁ and D ₂ , respectively, and waveform (G) is pixel 20. A ₁₁
Are shown respectively.

The driving method in one SF will be described sequentially. First, the pixel 20 that has emitted light in the immediately preceding SF is erased by the erase pulse E. Next, all the pixels 20 are forcibly discharged once by the preliminary discharge pulse PP, and the preliminary discharge is erased by the preliminary discharge erase pulse PE. As a result, a write discharge easily occurs.

After erasing the preliminary discharge pulse PP, the scan electrode S
₁ is applied at to S _m when the scan pulse PS split, supplies data pulses D corresponding to the light emission data to the column electrodes D ₁ to D _n in accordance therewith, to rise to selectively write discharge. The shaded portions of the data pulses D in the waveforms (E) and (F) indicate that the presence or absence of a pulse is determined according to the presence or absence of data to be written. This example shows a case where data is written to pixels a ₁₁ and a ₂₂ as a data voltage waveform.

In the pixel 20 to which the writing discharge has been performed, a positive charge called a wall charge is accumulated on the scan electrode 13b, and the positive potential caused by the wall charge and the first potential applied to the sustain electrode 13a are generated.
The first sustain discharge is generated by superimposition of the first sustain pulse H1. When the first sustain discharge occurs, the sustain electrode 13
A positive wall charge is accumulated on the scan electrode 13a, and a negative wall charge is accumulated on the scan electrode 13b. The second time is obtained by superimposing the potential of the wall charge on both electrodes and the sustain pulse H2 applied to the scan electrode 13b. Sustain discharge occurs. In the pixel 20 to which the writing discharge has been performed in this manner, the sustain discharge is maintained between the adjacent sustain electrode 13a and scan electrode 13b. The light emission luminance of each SF is controlled by the number of times of the sustain discharge. The state in which the writing is performed and the sustain discharge is sustained in this manner is referred to as SF emitting light.

In the non-writing pixel 20 where writing is not performed, no wall charge is formed on the scanning electrode 13b.
The voltage of the sustain pulse H1 applied to the
Sustain discharge does not occur if it is adjusted in advance to such an extent that no discharge occurs when only 1 is used. This is referred to as non-emission of SF.

Next, a conventional PDP for driving this PDP
Referring also to FIG. 10 which shows an example of a driving device by a block, the PDP driving device shown in FIG. 10 receives a received signal from an antenna (not shown), performs video detection, and performs video detection.
And a receiving unit 8 for generating each of the analog video signals VA
A synchronization signal detection circuit 1 for detecting a synchronization signal SS from the video signal V, an A / D converter 2 for A / D converting the analog video signal VA to generate a digital video signal VD, and an inverse of the digital video signal VD. An inverse gamma correction circuit 3 that performs gamma (γ) correction and generates an SF selection signal DF; a timing signal generation circuit 4 that generates timing signals SH and SV in response to the supply of a synchronization signal SS;
And SF selection signal DF are temporarily stored and SF selection data M
A memory circuit 5 including a memory for outputting D and a field signal FF and a memory controller for controlling the memory;
A row driver 6 for driving the scan electrode 13b in response to the supply of the timing signal SV and the field signal FF;
A column driver 7 that drives the column electrode 14 in response to the supply of the F selection data MD and the timing signal SV is provided.

Next, the operation of the conventional PDP driving device will be described with reference to FIG. 10. A received signal received by an antenna is sent to a receiving unit 8, which performs video detection. Video signal V and analog video signal V
A is generated and supplied to the synchronization signal detection circuit 1 and the A / D converter 2, respectively. The synchronization signal detection circuit 1 detects the synchronization signal SS in response to the supply of the video signal V, and supplies the synchronization signal SS to the timing signal generation circuit 4. The timing signal generation circuit 4 generates horizontal and vertical scanning timing signals SH and SV in response to the supply of the synchronization signal SS, and supplies them to the memory circuit 5, row driver 6, and column driver 7, respectively. On the other hand, the A / D converter 2 A / D converts the supplied analog video signal VA, generates a digital video signal VD, and supplies the digital video signal VD to the inverse gamma correction circuit 3. The inverse gamma correction circuit 3 performs inverse gamma correction of the digital video signal VD, generates an SF selection signal DF proportional to a required luminance level, and supplies the SF selection signal DF to the memory circuit 5. The memory circuit 5 stores the SF selection signal DF in synchronization with the timing signal SH.

In response to the supply of timing signal SH, memory circuit 5 sets SF selection data MD corresponding to SF selection signal DF.
And the field signal DF are supplied to the column driver 7 and the row driver 6, respectively. The row driver 6 generates a scanning pulse PS in response to the supply of the timing signals SV and FF, and drives the scanning electrode 13b. The column driver 7 is SF
The column electrode 14 is driven in response to the selection data MD and the supply of the timing signal SV.

In general, the phosphor 17 emits light when electrons in a trace amount of impurities called an activator present in the phosphor are excited to a high energy level by energy absorption from ultraviolet light, and then the low energy energy before excitation is emitted. It is caused by surplus energy in returning to the level being emitted in the form of light. At this time, in order to return from the excited state to the original low energy level state, a time peculiar to each phosphor (called afterglow time) is required.

As compared with the amount of the activator before excitation, the amount of ultraviolet light incident on the phosphor is large, and therefore, when the number of photons of the incident ultraviolet light increases, the amount of visible light generated with respect to the incident ultraviolet light amount increases. The number of photons, and thus the proportion of the amount of visible light emitted from the phosphor, decreases with increasing incident ultraviolet light. This is called luminance saturation of the phosphor. This luminance saturation is generally remarkable for a phosphor having a long afterglow time.

Due to the luminance saturation of the phosphor, each S
When the number of sustain discharges at F is set to 2 ⁿ times the number of sustain discharges corresponding to the unit light emission luminance, the light emission luminance L does not reach 2 ⁿ times this unit light emission luminance but becomes lower than it. This is SF
Is referred to as luminance saturation within.

Similarly, due to the luminance saturation of the phosphor,
Even if the number of sustain discharges is substantially the same, the light emission luminance is different between the case where the same occurs in one SF and the case where it is the sum of a plurality of SFs, and the light emission luminance L is smaller in the former case. This is called luminance saturation between SFs.

Each of the eight SF1 to SF8 has 2
Referring to FIG. 11 showing the relationship between the level of the SF selection signal DF and the light emission luminance L when ⁿ (4, 8, 16,..., 512) sustain pulses are given, here, the SF selection signal DF 1 unit corresponds to the sustain pulse number of 4 pulses. The discontinuous portion of the change in light emission luminance in the figure is mainly caused by luminance saturation between SFs, and is a phenomenon peculiar to the case where the SF method is used. Further, the decrease in the luminance L from the ideal value indicated by the broken line is affected by both the intra-SF luminance saturation and the inter-SF luminance saturation. As a matter of course, it is impossible to properly display an image that requires a minute gradation difference with such a gradation luminance change.

[0024]

The above-mentioned conventional PDP
In the driving method and the driving device thereof, the gradation luminance change becomes discontinuous due to luminance saturation in a subfield (hereinafter referred to as SF) and between SFs due to luminance saturation of the phosphor, and required linearity is obtained. For this reason, there is a disadvantage that it is impossible to properly display an image that requires a minute gradation difference.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and a device for driving a PDP that accurately displays required gradation luminance in view of the above-mentioned drawbacks.

[0026]

According to a method of driving a plasma display of the present invention, a discharge gas for generating ultraviolet light for exciting a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent; First to n-th (n) light-emitting luminances are weighted for one field, including at least a plurality of scanning electrodes corresponding to the scanning lines of a display cell coated with a visible light-emitting phosphor and a plurality of column electrodes orthogonal to the scanning electrodes. Is an integer of 2 or more).
In the method for driving a plasma display panel that performs gradation display by selectively emitting light from the subfields, the (n-1) subfields other than the subfield having the smallest emission luminance among the n subfields , Each target value of the light emission luminance of the plasma display panel corresponding to the gradation level when each of them is selected and emitted independently is set to L1, and the target value is 1 from the gradation level L1.
(N-1) light emitting luminances other than the sub-field having the minimum light emitting luminance so that the target value L1 is smoothly connected to at least L2 and L3, assuming that the light emitting luminances corresponding to the gradation level smaller by two levels are L2 and L3, respectively. A first step of sequentially determining the target value L1 from the subfield having the smaller light emission luminance for the subfield of (n);
1) setting the number of sustain discharges such that the light emission luminance becomes the target value L1 when each of the subfields is selected.

In the driving apparatus for a plasma display according to the present invention, a discharge gas for generating ultraviolet light for exciting a visible light emitting phosphor is sealed between at least one of two transparent substrates. A plurality of scanning electrodes corresponding to the scanning lines of a display cell coated with a plurality of scanning electrodes, and a plurality of column electrodes orthogonal to the scanning electrodes, and the first to n-th (n is 2 or more) (Integer) time-division, and the first to n-th subfields are selectively illuminated to perform gradation display. Therefore, a predetermined inverse gamma correction is performed on the digital video signal, and the subfield selection signal is output. An inverse gamma correction circuit, a timing signal generation circuit for generating a predetermined timing signal in response to the supply of a synchronization signal, and a control circuit for controlling the timing signal. A memory circuit for temporarily storing a field selection signal and outputting subfield selection data; a row driver for driving scan electrodes in response to the supply of the timing signal; and a row driver for responding to the supply of the subfield selection data and the timing signal. A column driver for driving the column electrodes, wherein the light emission characteristics of the visible light-emitting phosphor and the light emission characteristics of the ultraviolet light of the gas depend on a luminance saturation characteristic and A second gamma correction circuit configured to correct the subfield selection signal and generate a corrected subfield selection signal so as to smoothly connect discontinuities in luminance change caused by a combination of the first to nth subfields. I have.

[0028]

Next, referring to FIG. 1 showing a first embodiment of the present invention by a processing flow (A) and a principle diagram (B), the driving method of the PDP of this embodiment shown in FIG. The weighting order of the light emission luminance L of each subfield (hereinafter, SF) (for example, the descending order shown in FIG. 8) and the number of sustain discharges in SF8 with the minimum light emission luminance in this case are set (step A).
1) Assuming that the luminance L is expressed by the equation (1), SF
SF selection signal DF level 12 when only 1 emits light
The luminance corresponding to 8 is L ₁ , and all SF 2 except SF ₁
SF selection signal DF level 12 when SF8 emits light
7 and the emission luminance L ₂ corresponding to the next lower level (SF2
The light emission luminance corresponding to SF selection signal DF level 126 of ～SF7) and L _3. At this time, the light emission luminance L ₁ at the SF selection signal DF level 128 is determined by the following equation so as to be smoothly connected to L ₂ and L ₃ (step A).
2).

L ₁ = L ₂ + (L ₂ −L ₃ ) (2) In this way, the target value of the luminance L ₁ when only one SF, that is, SF 1 is selected, is obtained. SF1 in case
Setting the number of sustain discharges of the inner so that L ₁ luminance is the target value (step A3).

[0030] As described above, SF selection signal level corresponding the luminance L ₁ of DF for selecting emitting only one SF is, the light emission luminance in the SF selection signal DF 1 level smaller SF selection signal DF level than the level of On the other hand, when only one SF is selectively illuminated, the SF
Adjust the brightness of.

This operation is repeated for all the S except for the SF whose SF selection signal DF level is the lowest level 1 (SF8 in this case).
F is sequentially performed from a low level to a high level, that is, from SF7 to SF1, and each SF, that is, SF1 to SF1
The number of sustain discharges for each of SF8 is determined (Step A)
4).

Here, the target value L ₁ of the light emission luminance of SF7 alone.
Is the SF selection signal DF level 1 which is one level smaller than this because the SF selection signal DF level in this case is 2.
A brightness L ₂ is the luminance at SF8 alone emission, 2
L, which is the luminance of the SF selection signal DF level 0 having a small level
_Assuming that ₃ is 0, L ₁ = 2L ₂ using equation (2).
This is simpler than the calculation of the luminance target value L ₁ and the number of sustain discharges in other SFs.

FIG. 2 shows the light emission luminance L with respect to the SF selection signal DF level when the setting is performed by the method of the present embodiment.
Referring to (A), the continuity of the gradation luminance change is improved and an appropriate image display can be performed by a relatively simple operation as compared with FIG. 11 in which a conventional simple 2 ⁿ number of sustain discharges is set. Become.

Further, in this embodiment, in step A2, S
Emission luminance L ₁ is S in F selection signal DF level 128
Light emission luminance L ₂ , S at F selection signal DF level 127
Was used as a state smoothly connected to the light emitting luminance L ₃ (2) equation in F selection signal DF level 126, the same effect can be obtained using other relational expression representing a smooth connection.

However, even if such correction is performed, a discontinuous point still remains in the light emission luminance. This is because, for example, a plurality of SFs (in this case, SF1 and SF2) selectively emit light as in the SF selection signal level 192, and the SF1, SF3 to SF8 corresponding to the SF selection signal level 191 lower by one level are selectively emitted. This is because the light emission luminance in this case remains discontinuous.

The second embodiment of the present invention which further corrects the SF selection signal DF level in order to solve such a discontinuity and the problem that the light emission luminance is not proportional to the SF selection signal DF level is common to FIG. 3 are denoted by common reference characters / numerals and similarly shown in blocks.
Referring to FIG. 1, the PDP driving apparatus according to the present embodiment includes a synchronization signal detection circuit 1, an A / D converter 2, an inverse gamma correction circuit 3, a timing signal generation circuit 4, Memory circuit 5, row driver 6, column driver 7
Gamma correction circuit for correcting the SF selection signal DF output from the inverse gamma correction circuit 3 using an inverse function of the function indicating the relationship between the SF selection signal level and the light emission luminance in addition to the reception unit 8 9 is further provided.

Next, the operation of the present embodiment will be described with reference to FIG. 3. First, as in the prior art, the analog video signal VA received and detected by the receiver 8 and output is converted to an A / D converter. A / D conversion is performed at 2 to generate a digital video signal VD, which is supplied to the inverse gamma correction circuit 3. Inverse gamma correction circuit 3
Generates an SF selection signal DF proportional to a required luminance level by performing inverse gamma correction of the digital video signal VD,
It is supplied to the gamma correction circuit 9.

Next, the second gamma correction circuit 9
The supplied SF selection signal DF is corrected by using an inverse luminance function which is an inverse function of a luminance function indicating the relationship between the SF selection signal DF level and the emission luminance L as shown in FIG.
A correction SF selection signal CDF as shown in FIG . S F Select i.e. PDP driving do in this interpolation SF selection signal CDF.

Referring to FIG. 4A showing an example of the second gamma correction circuit 9 according to the present embodiment, the second gamma correction circuit 9 calculates the above-mentioned correction SF selection signal CDF for the SF selection signal DF. ROM that stores conversion correction characteristics of
A table 91 is provided.

The reason for using the ROM table 91 is that the SF selection signal DF and the correction SF selection signal CDF are used as described above.
This is because there are some discontinuities in the function of. In this embodiment, since 256 gradations are displayed by emitting and not emitting eight SFs, the SF selection signal DF has eight bits. Therefore, the respective converted output signals corresponding to each of the 256 types of 8-bit SF selection signals DF, that is, the corrected SF selection signals CDF are stored in the ROM in advance, and
If SF selection is performed using the correction SF selection signal CDF, the gradation change becomes linear.

Referring to FIG. 4B showing the configuration of the inverse gamma correction circuit 3A which characterizes the third embodiment of the present invention.
The inverse gamma correction circuit 3A includes a ROM table 92 storing a correction function obtained by multiplying the inverse gamma correction function of the second embodiment by the inverse luminance function as the second gamma correction function. Correction and the second gamma correction to one R
The correction is performed according to the OM table, and the direct correction SF selection signal CDF is generated in response to the supply of the digital video signal VD. With such a configuration, the effects of the present invention can be sufficiently obtained while the circuit configuration is as simple as that of the related art.

In the second and third embodiments, for concreteness of the explanation, a circuit configuration in which the A / D converter 2 and the inverse gamma correction circuit 3 are provided before the second gamma correction circuit 9 is adopted. However, as the input method to the second gamma correction circuit 9, other different combinations are possible.

The first combination is a case where a digital signal proportional to the luminance, that is, an SF selection signal DF is supplied to the PDP driving circuit, and this signal DF is directly supplied to the second gamma correction circuit 9 and the corresponding correction is performed. An SF selection signal CDF is output.

The second combination is a case where an analog video signal proportional to luminance is supplied. This analog video signal is converted into a digital signal proportional to luminance, that is, a second signal DF, by the A / D converter 2. It is supplied to a gamma correction circuit 9.

In the third combination, an analog video signal VA is converted into an analog video signal proportional to luminance by an analog inverse gamma correction circuit, and this analog video signal is converted to an A / D signal.
The signal is converted into a digital signal DF by the converter 2 and supplied to the second gamma correction circuit 9.

FIG. 5 is a block diagram showing a fourth embodiment of the driving method of the plasma display according to the present invention, in which constituent elements common to those in FIG. This embodiment is different from the second embodiment in that the analog video signal VA is supplied in three systems of RGB in order to perform multi-color or full-color display. D converter 2
A to 2C, inverse gamma correction circuits 3A to 3C, and second gamma correction circuits 9A to 9C. When a plurality of phosphors are used to apply different phosphors to each pixel, the second gamma correction is performed for each phosphor. Is performed for each color of RGB in accordance with the light emission saturation characteristics of the above.

For example, in the case of two kinds of phosphors having emission saturation characteristics as shown in FIG. 11, if the signal conversion shown in FIG. 2B is performed for each of them, SF selection by the corrected SF selection signal CDF is performed. Accordingly, both of the phosphors can realize a smooth and linear luminance change with respect to the input signal. Therefore, although it takes more time than the first embodiment,
There is an advantage that more accurate correction can be made.

The second to fourth embodiments can of course be used in combination with the first embodiment. In this case, first, the point at which the light emission luminance changes discontinuously is reduced in advance by the first embodiment, and thereafter, the linearity between the SF selection signal and the light emission luminance is obtained by the second to fourth embodiments. To

In the above description, the case of using the scan sustain / separation drive waveform of FIG. 9 as the PDP drive waveform has been described. However, the present invention is not limited to this. It goes without saying that the present invention can be applied to a case where a drive waveform of a mixed system is used.

[0050] Further weighted order of emission brightness of divided SF, and with respect to the weighted side, be other than weighting of descending and 2 ⁿ ratio of 8 was used in description, SF selection signals discontinuous luminance change occurs Only the DF level is different, and there is no difference in the correction procedure.

The AC type PDP has been described above.
Needless to say, all of the first to fourth embodiments can be applied to a DC type PDP.

[0052]

As described above, the method of driving a PDP according to the present invention provides a light emission luminance corresponding to the second to n-th gradation levels when only each of the second to n-th subfields is selected. The respective target values are L1 and the light emission luminances corresponding to the gradation levels one and two levels smaller than the second to nth gradation levels are L2 and L3, respectively, and the target value L1 is L1 = L2 + (L2-L3). A first step of sequentially determining the second to n-th subfields so as to satisfy the following condition: and a sustain discharge so that the emission luminance becomes the target value L1 when each of the second to n-th subfields is selected. Since the second step of setting the number of times is included, the continuity of the gradation luminance change is enhanced, and an image requiring a minute gradation difference can be appropriately displayed, so that a high gradation image or a natural image can be displayed. Subtle color change There is an effect that can express high fidelity video display displays the image can be reproduced with fidelity luminance and color-tone of with.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a first embodiment of a method of driving a plasma display panel according to the present invention and a diagram illustrating a principle.

FIG. 2 is a characteristic diagram illustrating an example of a luminance characteristic and a second gamma correction characteristic according to the driving method of the plasma display panel of the present embodiment.

FIG. 3 is a block diagram showing a plasma display panel driving device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating an example of a second gamma correction circuit of the present embodiment and an example of an inverse gamma correction circuit of the third embodiment.

FIG. 5 is a block diagram showing a plasma display panel driving device according to a fourth embodiment of the present invention.

FIG. 6 is a plan view and a cross-sectional view illustrating an example of a configuration of a general plasma display panel.

FIG. 7 is a plan view showing details of a configuration of an electrode of the plasma display panel of FIG. 6;

FIG. 8 is an explanatory diagram of gradation display by a subfield method.

FIG. 9 is a diagram showing an example of a drive voltage waveform and a light emission waveform in one subfield of the plasma display panel.

FIG. 10 is a block diagram showing an example of a conventional plasma display panel driving device.

FIG. 11 is a characteristic diagram showing a relationship between a level of an SF selection signal and a light emission luminance in a conventional method of driving a plasma display panel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Synchronous signal detection circuit 2, 2A-2C A / D converter 3, 3A-3C Inverse gamma correction circuit 4 Timing signal generation circuit 5 Memory circuit 6 Row driver 7 Column driver 8 Receiver 9, 9, 9A-9C Second gamma correction circuit 10 the plasma display panel 11 first insulating substrate 12 and the second insulating substrate _{13a, C 1, C 2,} ..., C m sustain electrodes _{13b, S 1, S 2,} ..., S m scanning electrodes 13c metal electrodes 14, D ₁ , D ₂ ,..., D _n column electrode 15 Discharge gas space 16 Partition wall 17 Phosphor 18 a, 18 b Insulating layer 19 Protective layer 20 Pixel 21 Seal part

Claims (7)

(57) [Claims] A discharge gas generating ultraviolet light for exciting a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent, and a display cell corresponding to a scanning line of a display cell coated with the visible light emitting phosphor. A plurality of scanning electrodes and a plurality of column electrodes orthogonal to the scanning electrodes;
(N is an integer of 2 or more) in a driving method of a plasma display panel that performs time-division into subfields and selectively emits light in the first to nth subfields to perform gradation display. For each of the (n-1) subfields other than the subfield having the lowest light emission luminance among the subfields, each target value of the light emission luminance of the plasma display panel corresponding to the gradation level when each of them is selected and emitted independently. L1 and light emission luminances corresponding to gradation levels one level and two levels smaller than the gradation level L1 are L2 and L3, respectively, and the target value L1 is at least L1.
A first step of sequentially determining a target value L1 for the (n-1) sub-fields other than the sub-field having the lowest light emission luminance so as to be smoothly connected to L2 and L3, starting from the sub-field having the lowest light emission luminance. A second step of setting the number of sustain discharges such that the light emission luminance is equal to the target value L1 when each of the (n-1) subfields is selected. Drive method. 2. A display cell in which a discharge gas for generating ultraviolet light for exciting a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent, and the visible light emitting phosphor is applied to a display cell corresponding to a scanning line. A plurality of scanning electrodes and a plurality of column electrodes orthogonal to the scanning electrodes;
(N is an integer of 2 or more) in a driving method of a plasma display panel for performing gradation display by time-division into subfields and selectively emitting the first to nth subfields. The discontinuity of the luminance change caused by the luminance saturation characteristic depending on the luminous characteristic of the body and the luminous characteristic of the ultraviolet light of the gas and caused by the combination of the first to nth subfields is smoothly connected. A method of driving a plasma display panel, comprising performing a second gamma correction for correcting the subfield selection signal. 3. In the second gamma correction, a luminance saturation characteristic dependent on a light emission characteristic of the visible light emitting phosphor and a light emission characteristic of the ultraviolet light of the gas, and in the first to n-th subfields. 3. The method according to claim 2, wherein the luminance change caused by the combination is corrected so that the light emission luminance is proportional to the video signal. 4. A discharge cell for generating ultraviolet light which excites a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent. A plurality of scanning electrodes and a plurality of column electrodes orthogonal to the scanning electrodes;
(N is an integer of 2 or more) in a time-division manner, and the first to n-th subfields are selectively illuminated to perform gradation display, so that a predetermined inverse gamma correction is performed on the digital video signal. An inverse gamma correction circuit for generating a subfield selection signal, a timing signal generation circuit for generating a predetermined timing signal in response to the supply of a synchronization signal, and temporarily storing the subfield selection signal by controlling the timing signal. A memory circuit for outputting field selection data, a row driver for driving scan electrodes in response to the supply of the timing signal, and a column for driving the column electrodes in response to supply of the subfield selection data and the timing signal A plasma display panel driving device comprising a driver and a light emitting characteristic of the visible light emitting phosphor. The sub-field selection signal is so connected as to smoothly connect the discontinuity of the luminance change caused by the combination of the first to n-th sub-fields due to the luminance saturation characteristic dependent on the emission characteristic of the ultraviolet light of the gas. A plasma display panel driving apparatus, further comprising a second gamma correction circuit that corrects and generates a correction subfield selection signal. 5. The plasma according to claim 4, wherein said second gamma correction circuit includes a ROM including a table storing a level of said correction subfield selection signal corresponding to a level of said subfield selection signal. Display panel drive. 6. A display cell corresponding to a scanning line of a display cell in which a discharge gas for generating ultraviolet light for exciting a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent, and the visible light emitting phosphor is applied. A plurality of scanning electrodes and a plurality of column electrodes orthogonal to the scanning electrodes;
(N is an integer of 2 or more) in a time-division manner, and the first to n-th subfields are selectively illuminated to perform gradation display, so that a predetermined inverse gamma correction is performed on the digital video signal. An inverse gamma correction circuit for generating a subfield selection signal, a timing signal generation circuit for generating a predetermined timing signal in response to the supply of a synchronization signal, and temporarily storing the subfield selection signal by controlling the timing signal. A memory circuit for outputting field selection data, a row driver for driving scan electrodes in response to the supply of the timing signal, and a column for driving the column electrodes in response to supply of the subfield selection data and the timing signal A plasma display panel driving device comprising a driver and the driver. The discontinuity of the luminance change caused by the combination of the first to n-th subfields caused by the luminance saturation characteristic depending on the light emission characteristic of the photophosphor and the light emission characteristic of the ultraviolet light of the gas is smoothly connected. A plasma including a table storing a level of the corrected subfield selection signal corresponding to a level of the digital video signal to generate a corrected subfield selection signal obtained by correcting the subfield selection signal. Display panel drive. 7. A scanning gas corresponding to a scanning line of a display cell in which a discharge gas for generating ultraviolet light for exciting a visible light emitting phosphor is sealed between two substrates, at least one of which is transparent, and the visible light emitting phosphor is applied. A plurality of scanning electrodes and a plurality of column electrodes orthogonal to the scanning electrodes;
(N is an integer of 2 or more) in a time-division manner, and the first to n-th subfields are selectively illuminated to perform gradation display, so that a predetermined inverse gamma correction is performed on the digital video signal. First to third inverse gamma correction circuits for generating first to third subfield selection signals,
A timing signal generation circuit for generating a predetermined timing signal in response to the supply of a synchronization signal, and a memory circuit for temporarily storing the first to third subfield selection signals and outputting subfield selection data by controlling the timing signal And a row driver for driving a scan electrode in response to the supply of the timing signal, and a column driver for driving the column electrode in response to the supply of the subfield selection data and the timing signal. In the device, a discontinuity in luminance change caused by a luminance saturation characteristic dependent on a light emission characteristic of the visible light emitting phosphor and a light emission characteristic of the ultraviolet light of the gas and caused by a combination of the first to nth subfields. Are corrected so as to smoothly connect the first to third subfield selection signals. A plasma display panel driving device, further comprising first to third second gamma correction circuits for respectively generating third to third correction subfield selection signals.