JPS6119998B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a driving method for a scanning type plasma display device, and more particularly to a driving method for a plasma display device that takes into consideration the scanning order of each electrode.

(Prior art) In a scanning type plasma display device,
In order for the display screen to appear fixed, the same electrodes must be driven over and over again to give the appearance of a constant drawing.

Conventionally, a display device using this type of scanning method has a memory with a capacity for one screen inside the device, and display data information is read from the memory at regular intervals and displayed on the display screen. This display is achieved by sequentially applying driving pulses to the Y electrodes at a constant period.
Display was performed by scanning all the Y electrodes, selectively applying a driving voltage pulse to the X electrodes in synchronization with the Y electrode pulses, and igniting only the necessary cells.

In more detail, the operation of the conventional scanning method will be explained with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the drive timing, and FIG. 2 is a diagram explaining the operation. The Y electrodes are constantly scanned with applied voltages at the timings shown in FIG. 1a, b, and c. For example, if you want to discharge and ignite two cells (X ₁ , Y ₁ ) and (X ₃ , Y ₃ ), apply the driving voltage to the X ₁ and X ₃ electrodes at the timings shown in Figure 1 d and e. do. (X ₁ ,
The voltage applied to the Y ₁ ) cell and the (X ₃ , Y ₃ ) cell is f,
It becomes as shown in h. The (X ₁ , Y ₁ ) cell during the scanning period of Y ₁ (t ₀ to _{t 1} ) and the cell during the scanning period of Y ₃ (t ₂ to t ₃ ) have polarity from V to -V and from -V to V. A varying voltage is applied.

On the other hand, a half-selective voltage is applied to the (X _{1 ,} Y ₃ ) cell in the t ₀ - _{t 1} period and the (X ₃ , Y ₁ ) cell in the t 2 - t ₃ period, but the X electrode and Y electrode are Since this voltage is about half of the voltage applied to cells that are simultaneously selected, the voltage value can be set so that only cells that are selected at the same time are discharged, rather than being discharged when only one electrode is selected. When the discharge starts, the voltage is applied through the insulating film, so charged particles generated by the discharge adhere to the insulating film, creating a reverse voltage inside the cell, and the difference between that reverse voltage and the externally applied voltage. When the sum falls below the discharge stop voltage, the discharge stops. Therefore, when a voltage higher than the positive and negative discharge starting voltages as shown in f and h is applied, intermittent light shown in g and i is obtained. If the repetition time of this intermittent light is made faster than the visual response speed, it will appear as if the discharge is continuing continuously. If a plurality of cells with such characteristics are configured in the same display and a pulse voltage is selectively applied to each cell in a time-sharing manner, only the selected cells are discharged, and an arbitrary display can be obtained.

In this kind of plasma display device,
An on-voltage is applied to each parallel electrode of the first electrode group in a time-divisional manner, while a second
It has been proposed that crosstalk is prevented by forming at least every other parallel electrode of the electrode group and applying a display signal voltage alternately to each set of electrodes. (See Publication No. 90486). In addition, afterglow fluorescent discharge tubes are arranged in a matrix, and signals are sequentially applied to odd-numbered horizontal signal lines in the case of the first field of the input video signal, and signals are applied to the even-numbered lines in the case of the second field. A configuration is known in which signals are sequentially applied to horizontal signal lines for display (see Japanese Unexamined Patent Publication No. 48-6687).

(Problems to be Solved by the Invention) The conventional scan drive method that sequentially scans adjacent electrodes as described above has the problem that when the movement time of the scan and the eye movement are synchronized, an afterimage occurs on the human retina. Due to this effect, lightning-like bright lines are seen every time the eye moves, giving an unpleasant impression due to the image quality characteristics. These sharp lightning-like bright lines can be eliminated by increasing the scanning speed, but methods for doing so include increasing the driving frequency or decreasing the number of pulses continuously applied to one electrode. However, the former method causes technical difficulties, increases in price, and deterioration of electrical characteristics of the drive circuit itself, and the latter method causes deterioration of image quality characteristics, making it impractical.

Furthermore, even the method of scanning by skipping every other electrode was not sufficient to eliminate the lightning-like bright lines.

Furthermore, if an attempt is made to solve the problem by applying a fluorescent agent, it is undesirable because it increases the number of steps required for the panel and deteriorates the fluorescent agent, resulting in a shortened lifespan.

(Means for Solving the Problems) The driving method of the plasma display device of the present invention includes: a first electrode group arranged in parallel in a column direction across a sealed gas space; A plurality of second electrode groups are arranged in parallel in the row direction so as to be orthogonal to the second electrode group, and each intersection of these electrode groups is
It is applied to a discharge panel forming one dot of a plurality of characters to be displayed arranged in a column direction. Referring to the principle diagram of FIG. 5, scanning in the column direction of the characters starts from the electrode 1 at a preset position of the end character (for example, a), and then scans the adjacent character (for example, b). When scanning is completed to electrode 2 at the preset position of the last letter (for example, z) and the same goes to electrode 2 at the preset position of the last letter (for example, z), the scan returns to the preset position of the letter a at the end. Return to the electrode (m+1) at a position different from the electrode 1 in the character b, and then jump to the electrode (m+2) at a position different from the electrode 2 at the preset position of the adjacent character b. Performs interlaced scanning in the column direction from a to z. Furthermore, although not shown, the character is displayed on the discharge panel by applying a driving voltage corresponding to the character to be displayed to the second electrode group at a timing corresponding to the scanning in the column direction. do.

Here, nm (n, an integer of m≧3) in FIG. 5 indicates the total number of scanning electrodes, n indicates the number of rows constituting one character, and m indicates the number of characters per column.

(Example) Next, the present invention will be explained with reference to the drawings.

In order to simplify the explanation, a panel with a 7 x 9 dot configuration and a screen capacity of 4 characters is assumed to be 6.
An example in which electrodes are removed one by one will be described.

FIG. 3 is a block diagram showing one embodiment of the present invention, and FIG. 4 is a timing diagram thereof. First, in the case of writing data, characters to be displayed are coded and input from the keyboard KB, and are temporarily stored in the data register 1. The data is input to the temporary storage circuit 5 and stored sequentially. At this time, the writing position to the temporary storage circuit 5 is designated from the cursor address counter 3 via the address selector 4.

Next, the operation of displaying the data stored in the temporary storage circuit 5 on the plasma display 14 will be explained. The scan address counter 2 outputs the pulse series , , , shown in FIG.
and input terminals 11.2 and 11.3 of the X decoder 11. Also,,
The pulse sequence is input to the character generator 6 and is also input to the input terminal 9. of the Y decoder 9.
2, 9.3, and 9.4. X decoder 1
1, the pulse series is expanded 2-4 according to the X drive timing T input to the input terminal 11.1, and the pulses ~ are output terminals 11.10-1.
Occurs on 1.13. Further, the Y decoder 9 expands the pulse series 3-7 in accordance with the Y drive timing T input to the input terminal 9.1, and generates pulses . The outputs of the X decoder are input to input terminals 12.1 to 12.4 of the X scan drive circuit 12, respectively.

Further, the pulse outputs of the Y decoder are inputted to input terminals 10.1 to 10.7 of the Y scan drive circuit 10. The diode matrix 13 is divided and provided corresponding to each character. Y scan drive circuit 10
The output 10.10 of is the electrode S00, S10,...
_{. _} Similarly, outputs 10.11 to 10.16 are connected to electrodes S01, S11, ......, S31, ~S06, S
16, ......, S36 through diodes, respectively, and pulse output ~ (T ₁
~ T ₂ , ......, T ₆ ~ T ₇ period), V
Supply a pulsed voltage with potential.

On the other hand, the outputs 12.11 of the X-scan drive circuit 12 are connected to the electrodes _S00 to _S06 through diodes, respectively, and when receiving the pulse output of the supply. Output 12.12~12.14
Similarly, the electrodes S10 to S16, -, S30 to S3
6, and supplies pulse outputs each having a ground voltage when receiving pulse outputs (periods t ₁ to t ₂ , . . . t ₃ to _{t 4} ). At this time, the output pulses from both scanning drive circuits 10.12 are outputted in a complementary manner. The combination of the Y-scan drive circuit 10, the X-scan drive circuit 12, and the diode matrix 13 described above provides a configuration corresponding to the Y-scan drive circuit shown in FIG. 2.

Therefore, at a certain point during the t _{0 - t 1 period} , the ground potential is applied from the output terminal 12.11 to the electrodes S00 to S06, and then the ground potential is applied to the electrodes S00 to S06 from the output terminal 12.11.
0.10 is turned on and voltage V is applied to electrode S00. Since the output terminals 10.11 to 10.16 remain in the off state, no voltage is applied to the electrodes S01 to S06. By repeating the above process within the period _t0 to _t1 , a pulse train of V is applied from the ground to the electrode S00. _t1 to _t2
The period, t ₂ - t ₃ period and t ₃ - _{t 4} period are also processed in the same way, so that the output pulse train is connected to the electrodes S10 - S3.
0 is applied sequentially.

Next, during the T ₁ to T ₂ period, the electrode S
A voltage is sequentially applied to 01, S11, . . . S31. Thereafter, scanning is performed in the same manner up to the electrode S36.

On the other hand, the pulse sequence selected by the address selector 4 is input to the temporary storage circuit 5 as a read address. By this read address, cells S00 to S0 of the plasma display 14 are read.
6, S10 to S16, . . . , S30 to S36, an address in which a character to be displayed is stored is specified. Character code read from temporary memory circuit 5 and scan address counter 2
The character generator 6 generates a character pattern by the pulse series, , . This character pattern is once input to the shift register 7 and output to the data drive circuit 8. The data drive circuit 8 outputs outputs corresponding to the input character pattern to output terminals 8.1 to 8.9.

Now, for example, the output terminal 8. of the data drive circuit 8.
9, when the driving voltages shown in _{t0 to t1} and _t3 to _t4 of the T0 to _T1 period are applied, the half selection voltage applied to the S00 electrode during the _t0 to _t1 period. The intersection point 14.00 emits light due to the driving voltage. Also t ₁
Since there is no driving voltage during the ~ _t2 period and only the half-select voltage applied to the S10 electrode, the intersection point 1
4.10 does not emit light. Furthermore, in the period t ₃ to t ₄ , S
The intersection point 14.30 emits light due to the driving voltage with the half-select voltage of the 30 electrode.

In this way, S00, S10,... during the T ₀ to T ₁ period
..., S30 and six electrodes are skipped and driven. Similarly, during the T ₁ to T ₂ period, the output terminals 10 and 11
Electrodes S01, S11, ...... connected to
S31 is also connected to the electrodes S06, S16, ......, S3 connected to 10.16 during the T ₆ - T ₇ period.
6 are sequentially selected and all electrodes are scan-driven during the period T ₀ to T ₇ . In addition, in the above explanation, only the case of output terminal 8.9 was explained for simplicity, but in reality, the drive pulse voltage corresponding to the displayed character is output from output terminals 8.1 to 8.9 at the same timing. be done.

Above, we have explained the driving method of flying 6 electrodes at a time on a panel where one character is made up of 7 x 9 dots, but the specific factors that determine how many electrodes to jump are the number of scanning electrodes, dimensions, driving conditions, and control circuit. The optimum value must be considered, taking into account the ease of display, the viewing position of the display screen, etc.

In the embodiment shown in FIG. 3, the scanning order is moved from the left to the right of the screen with the electrodes S ₀₀ , S ₁₀ , S ₂₀ , S ₃₀ , but this is because the electrodes S ₃₀ , S ₂₀ , S ₁₀ , S ₀₀ and the screen are moved from the left to the right. There is no harm in changing the scanning order from right to left, or even in any combination of bidirectional orders. However, it is natural that data matching the scanning position must be controlled. If the number of electrodes to be inserted is optimally selected based on the usage conditions of the panel, the control circuit can usually be constructed simply by changing the wiring, which is practical.

(Effects of the Invention) As explained above, the present invention can accelerate the phase speed of the display by adopting the interlaced scanning method, so that sharp lightning-like bright lines that are seen when synchronized with eye movements are avoided. Therefore, a plasma display device with excellent display quality can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a drive timing diagram of a conventional plasma display device, Fig. 2 is an explanatory diagram of conventional operation, and Fig. 3 is a drive timing diagram of a conventional plasma display device.
FIG. 4 is a circuit diagram showing an embodiment of the present invention in a block diagram, FIG. 4 is a timing diagram explaining the operation of FIG. 3, and FIG. 5 is a diagram showing the principle of operation of the present invention. 1...Data register, 2...Scan address counter, 3...Cursor address register, 4...Address selector, 5...Temporary memory circuit, 6...Character generator, 7...
Shift register, 8...Data drive circuit, 9...
Scan address counter, 10...Y scan drive circuit, 11...X decoder, 12...X scan drive circuit, 13...Diode matrix, 14
...Plasma display panel.

Claims (1)

[Claims] 1. A first electrode group arranged in parallel in the column direction, sandwiching the enclosed gas space, and a second electrode group arranged in parallel in the row direction, perpendicular to the first electrode group. , and each intersection of these electrode groups is
In a discharge panel forming one dot of a plurality of characters to be displayed arranged in a column direction, scanning of the character in the column direction is performed by scanning an electrode at a preset position of an end character and then an adjacent character. Jumps to the electrode at the preset position of the character, and in the same way, when all characters are completed, returns to the electrode at a position different from the electrode at the preset position of the end character, and then jumps to the electrode at a position adjacent to it. All characters should be interlaced scanned in the column direction by jumping to electrodes at different positions from the electrodes at the preset positions of the characters, and should be displayed at timings corresponding to the scanning in the column direction. 1. A driving method for a plasma display device, characterized in that characters are displayed on the discharge panel by applying a driving voltage corresponding to characters to a second electrode group.