JPH0418594A - Plasma display device - Google Patents

Abstract

PURPOSE:To extend a display period wherein a panel illuminates and to improve the screen brightness of the display panel by dividing cathodes of the display panel into upper cathode and lower cathodes. CONSTITUTION:An upper cathode driving part 6 receives a display panel driving signal outputted by a driving pulse generation part 3 to drive the upper cathodes C1 - Cn/2 of the display panel 10 and drives a reset cathode URC and receives a display panel driving signal outputted by the driving pulse generation part 3 similarly to drive the lower cathodes Cn/2+1 - Cn and reset cathode LRC of the display panel 10. Thus, the upper cathode driving part 6 while scanning the cathodes of the display panel from the uppermost line toward the division part of a lower display panel scans the cathodes of the display panel from the lowermost line upward to the division part of the display panel. Thus, the scanning is so performed as to shorten the display stop period and the screen brightness is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma display device designed to improve the brightness of a DC type plasma display with a memory function.

[Conventional technology]

FIG. 3 is a block diagram showing the configuration of a conventional DC type plasma display device with a memory function. In FIG. 3, a synchronization signal input from a synchronization signal input terminal 1 is input to a drive pulse generation section 3 and a control signal generation section 4.

The drive pulse generator 3 receives the synchronization signal and generates a display panel drive signal, and the control signal generator 4 receives the synchronization signal and generates a control signal for use in converting a video signal.

On the other hand, the video signal input to the video signal input terminal 2 is input to the video signal converter 5. The video signal converter 5 receives the video signal and the control signal output from the control signal generator 4 and creates a display video signal.

The display video signal output from the video signal converter 5 and the display panel drive signal output from the drive pulse generator 3 are input to the upper anode driver 8.

The upper anode drive unit 8 receives these display panel drive signals and display video signals, and drives the display anode U of the display panel IO.
A, ~UA, and a scanning anode US are driven.

Similarly, the lower anode drive unit 8 receives the display panel drive signal and the display video signal, and drives the display anodes LA, ~LA, and the scanning anode LS of the display panel 10. .

Further, the cathode drive section 11 drives the cathodes C and -C of the display panel 10 in response to a display panel drive signal output from the drive pulse generation section. In addition, R.C.
is the reset cathode.

In such a DC-type plasma display device with a memory function, the charged particles generated by the discharge gradually decrease over time after the discharge stops, and if the charged particles are distributed in space, the restriking voltage increases. This phenomenon is utilized to continuously perform pulse discharge of a DC type display cell.

Generally, in order to display an image using such a display having a matrix-type electrode arrangement, for example, one row of horizontal electrodes is selected, all vertical electrodes are driven in parallel, and one row of horizontal electrodes is selected. All pixels in a row are written simultaneously, the discharge is started, and the discharge is maintained for a period of time.

On the other hand, scanning, that is, pixel writing is performed sequentially only in the vertical direction.

In addition, apart from these electrodes, an auxiliary electrode is provided in the vertical direction, and a pilot discharge for scanning is caused between the above-mentioned horizontal electrodes to smooth the start of the discharge between the above-mentioned 2TIFk. Take advantage of the briming effect.

Note that the above-mentioned horizontal electrode is called a cathode, the vertical electrode is called a display anode, and the auxiliary electrode is called a scan anode.

On the other hand, as display panels become larger, the display anode has a relatively high operating frequency from the viewpoint of discharge phenomena, and since the line capacitance of the electrode affects the drive waveform, it is necessary to vertically divide the display panel into upper and lower parts. is common.

At this time, the display anode and the scanning anode will be referred to as upper and lower parts.

Next, the operation shown in FIG. 3 will be explained. In FIG. 3, the drive pulse generator 3 generates a write pulse, a sustain pulse, and a scanning anode pulse as anode signals based on a synchronization signal, and as cathode signals, a scan pulse, an erase pulse,
Create reset pulse and shift clock.

The control signal generator 4 generates various signals for controlling the A/D (analog/digital) converter and field memory in the video signal converter 5 based on the synchronization signal.

In the video signal converter 5, the video signal is converted into a digital signal of sharp focus (k is a natural number) by an A/D converter, and after being stored in a field memory, it is read out bit by bit at a high speed.

Furthermore, as described above, since the display panel 10 is divided into an upper part and a lower part, it is necessary to read out the video signal for the upper part display and the video signal for the lower part display separately. The signal is read out as a video signal for display, and then the signal from the division point to the bottom line is read out as a video signal for lower display. This situation is shown in FIG. 6 (al).

Next, the timing shown in FIG. 5 will be explained regarding the drive section surrounded by the broken line in FIG. 3.

The upper anode drive section 8 receives write pulses and sustain pulses from the drive pulse generation section 3, receives a video signal for upper display from the video signal conversion section 5, and generates continuous sustain pulses as shown in FIG. 5(b). An anode drive signal is created in which a write pulse (FIG. 5(i)) selected by the video signal exists in the gap.

The lower anode drive unit 9 also receives the lower display video signal and performs the same operation.

The cathode drive section 11 receives a reset pulse (FIG. 5(a)), a scanning pulse and an erase pulse shown in FIG. 5(b), and a shift clock from the drive pulse generating section 3, and generates a reset cathode that triggers the start of scanning. The signal, scan pulse, and erase pulse are combined to create a cathode drive signal that shifts with a horizontal period H.

FIG. 5 shows a case where the display cell in the second row and second column of a display panel having display cells in n rows and m columns is lit, and the reset cathode signal by the reset pulse is connected to the reset cathode R.
In addition to C, a reset discharge is generated, followed by scanning anodes US,,LS.

Scanning pulses are applied from the upper anode drive section 8 and the lower anode drive section 9, respectively, to perform scanning sequentially at every horizontal period H.

In this example, as shown in FIG. 5(C), the discharge starts at the point where the scanning pulse applied to the cathode C2 and the writing pulse of the display anode UA shown in FIG. 5(i) overlap, and before the erasing pulse. The discharge is maintained until the edge. The maintenance period is determined by the load for each focus when the video signal is digitized.

FIG. 4(a) shows how a conventional display panel is driven, with time plotted on the horizontal axis. The vertical direction represents the top and bottom of the display panel.

Here, the number of quantization bits is k, the horizontal period is H, the number of lines is n, the LSB display (maintenance) period is X, and the vertical period V
Expressing this, when the number of display panel dividing lines is T, it becomes as follows.

Therefore, the total display period X of all bits is expressed as.

Generally, when displaying an image, the horizontal period H1, the vertical period ■, and the gradation are fixed, so the total display period X is the number of lines n
becomes smaller in proportion to

[Problem B to be Solved by the Invention] Since the conventional DC type plasma display device with a memory function is configured as described above, the display period increases in proportion to the number of cathode lines. There was a problem in that the larger the number, the lower the screen brightness.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a plasma display device that can improve screen brightness by performing scanning that reduces the display dwell period.

[Means for Solving the Problems] A plasma display device according to the present invention includes a lower cathode drive section that drives a cathode at the top of the display panel, and a lower cathode drive section that drives the cathode at the bottom of the display panel. It is something that

[For production]

In this invention, the upper cathode drive section scans from the top line of the cathode of the display panel toward the divided portion of the display panel below, and at the same time, the lower cathode drive section scans from the bottom line of the display panel upward from the divided portion of the display panel. Scan towards.

〔Example〕

Embodiments of the plasma display device of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment.

In FIG. 1, parts that are the same as those in FIG. 3 are given the same reference numerals to avoid redundant explanation, and only parts that are different from those in FIG. 3 will be explained.

As is clear from comparing Figure 1 with Figure 3,
In the figure, parts indicated by numerals 1 to 5, and 8 to 10 are the same as in FIG. 3, and in this FIG. 1, instead of the single cathode drive section 11 in FIG. That is, an upper cathode drive section 6 and a lower cathode drive section 7 are provided. The other configurations are the same as in FIG. 3.

The upper cathode drive unit 6 receives the display panel drive signal output from the drive pulse generation unit 3, drives the upper cathodes 01 to C, 7□ of the display panel IO, and drives the reset cathode U.
It drives the RC.

Similarly, the lower cathode drive section 7 receives the display panel drive signal output from the drive pulse generation section 3 and drives the lower cathodes Cn/□, . . . ~C,, and the reset cathode LRC of the display panel 10. It is something that is driven.

Therefore, the cathode of the display panel 10 is divided into upper and lower parts.

Next, the operation will be explained. The operation up to the control signal generation section 4 and the operation up to the video storage of the video signal conversion section 5 are performed in the third step.
The operation is similar to the conventional operation shown in the figure.

The field memory of the video signal converter 5 is read out bit by bit at a high speed, but the video signal for upper display is read from the top line of the screen to the dividing point of the display panel.

Similarly, the video signals for displaying the lower part are read out simultaneously for the upper and lower parts. This situation is shown in FIG. 6 (bl).

The upper anode drive unit 8 and the lower anode drive unit 9 receive a write pulse and a sustain pulse from the drive pulse generator 3, and receive an upper display video signal and a lower display video signal output from the video signal converter 5, respectively. Then, an anode drive signal is created in which write pulses selected according to the video signal are present in gaps between successive sustain pulses, similar to the conventional example shown in FIG.

Further, the cathode drive section 6 and the lower cathode drive section 7 receive a reset pulse, a scan pulse, an erase pulse, and a shift clock from the drive pulse generation section 3, and output them in a positional relationship as shown in FIG.

That is, the reset cathodes URC at both ends of the display panel 10
, LRC are applied with reset cathode signals URC (Fig. 2 (a)) and LRC (Fig. 2 (j)), respectively, which trigger the start of scanning. 2(e) and 2(f)), the output of the upper cathode drive unit 6 with the horizontal period H is shown in FIGS. ), a downwardly shifting cathode drive signal is output and applied to the cathode CI-C,/z.

Similarly, the output of the lower cathode drive unit 7 outputs a cathode drive signal that shifts upward from the bottom line of the display panel 10 toward the divided portions as shown in FIG.
...As shown in Fig. 2(f), the cathode C1C, , C force, □. , add to.

FIG. 4(b) shows how the display panel 10 is driven by the operations described above, with time plotted on the horizontal axis.

Here, if the vertical period V is expressed as the quantization focus number is 5, the horizontal period is H, the number of lines is n, and the LSB display (maintenance) period is y, and the number of display panel dividing lines is T, then, Become.

Therefore, the total display period Y of all bits is expressed as .

Comparing this equation (II) with the above equation (r), the total display period decreases in proportion to the number of lines n; Under the same key conditions, the total display period is longer than before.

[Effects of the Invention] As described above, according to the present invention, the cathode of the display panel is divided into an upper cathode and a lower cathode, and the upper cathode is scanned by the upper cathode drive unit from the top line downward toward the divided portion of the display panel. However, at the same time, the lower cathode drive section is configured to scan upward from the bottom line toward the divided parts of the display panel, so the display period during which the panel is lit can be extended, and the screen of the display panel can be extended. It has the effect of improving brightness.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a plasma display device according to an embodiment of the present invention, FIG. 2 is a drive timing diagram of a display panel for explaining the operation of the same embodiment, and FIG. 3 is a conventional DC with memory function. Figure 4 is a block diagram of a type plasma display device (the barrel is a conventional D with memory function).
(b) is a timing diagram showing how the display panel of the C-type plasma display device is driven; FIG. 4 is a timing diagram showing how the display panel is driven in the plasma display device of the present invention; FIG. Conventional DC with memory function
FIG. 6 is a timing diagram for explaining the operation of a DC-type plasma display device with a memory function, and FIG. It is a diagram. 3... Drive pulse generation section, 4... Control signal generation section,
5... Video signal conversion section, 6... Upper cathode drive section, 7
...Lower cathode drive section, 8...Upper anode drive section, 9.
...Lower anode drive section, 10...Display panel. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Is it a tether for individual children? Station To1° Theory'M To Station 0 Drops Heisei 1, Indication of Case Patent Application No. 1847 2, Name of Invention Plasma Display Display Device 3, Person Making Amendment Representative Target of Amendment 6, Contents of Amendment (1) rUs on page 3, line 13 of the specification, I is rus
~Corrected as USaztJ. (2) "LSI J" on page 3, line 18
~LS-ztJ. (3) On page 7, lines 10 to 15, "by reset pulse...go" was changed to "Add a reset cathode drive signal to the reset cathode RC, scan anodes US, -US,
, □, and then a scanning pulse is applied from the cathode drive unit 11 to cause the scanning anodes US, -
Scanning is performed sequentially every horizontal period H while generating auxiliary discharge between US, /□ and LS, to LS, /□. ”
and correct it. (4) Correct “X=” on page 8, line 12 of the same page to “X=”. that's all

Claims (1)

[Claims] The display electrodes are vertically divided into two at the center and arranged horizontally, and the display electrodes are vertically divided into two at the center and arranged at right angles to the upper and lower display electrodes. a display panel having a cathode; a drive pulse generation section that generates a display panel drive signal from a synchronization signal; a control signal generation section that generates a control signal for converting a video signal from the synchronization signal; a video signal converter that generates a display video signal from the signal, and selects one row of the display electrodes divided into upper and lower halves from the display panel drive signal and the display video signal to maintain discharge for a certain period of time. The upper anode drive section and the lower anode drive section receive the display panel drive signal and sequentially scan the upper cathode in the vertical direction from the top toward the center to generate a discharge at a position orthogonal to the display electrode. An upper cathode drive unit that displays an image, and a lower cathode that receives the display panel drive signal and simultaneously scans the lower cathode in a vertical direction from the bottom to the center in order at a position orthogonal to the display electrode. A plasma display device comprising a lower cathode drive section that displays an image by causing discharge.