JPS6028100B2 - Plasma display device with alarm display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma display device, and more particularly to a plasma display device with an alarm display that has a function of displaying a warning before the end of its life.

2. Description of the Related Art Plasma display devices are widely used as display devices that display characters, numbers, symbols, etc. by selecting a plurality of electrodes.

This display device has a finite lifespan, and if used for a long period of time, it will no longer be able to achieve normal display functions. However, it was impossible to know such a lifespan in advance. moreover,
There are two types of plasma display devices: an X-Y dot matrix type plasma display device in which display electrodes are arranged linearly, and a segment type plasma display device in which display electrodes are arranged in a ta-shape, that is, a segment shape. Characters, numbers, and symbols are displayed by decoding and then using a matrix diode gate to selectively emit light from segments corresponding to each input signal, but normal electrical signals corresponding to input signals are not displayed on the plasma display. Even if the segment is added to the panel, if some kind of malfunction has occurred within the panel, and even if a specific segment is electrically selected, it will not emit discharge light, an error message will be displayed.

For example, when the number display is displayed in 7 segments, even if the input signal is 8 and the electrical signal applied to the display panel is 8, the life of the center segment of the evening has expired and no light is emitted. becomes. There are many cases where display devices are used in important places such as displaying money transfers, and the inconvenience caused by the above-mentioned fraudulent display is extremely large. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a plasma display device that can indicate in advance that the display life has expired.

Another object of the present invention is to provide a plasma display device that can eliminate inconveniences caused by erroneous display in advance. According to the present invention, it is possible to obtain a plasma display device in which an alarm electrode for alarm display is provided independently of the display electrode, and the driving frequency is increased so that the life of the alarm electrode is shorter than the life of the display electrode. .

That is, according to the present invention, in a plasma display device equipped with a first display electrode that displays characters, numbers, symbols, etc. by selectively driving a plurality of electrodes in accordance with input signals, when the device is driven, second driven
A display electrode is provided independently of the first display electrode, and the drive frequency of the second display electrode is made higher than the drive frequency of the first display electrode, so that the life of the second display electrode is increased. A plasma display device with an alarm display is obtained, which is characterized in that the life span of the first display electrode is shorter than that of the first display electrode.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a block diagram of a conventional plasma display device. The input signal is input to a 7-segment decoder, and within this 7-segment decoder, the input 4-bit signal is decoded into a 7-segment signal corresponding to the display segment and sent to the drive circuit 2, which drives the plasma display. The signal stepped up to the required voltage is sent to the plasma display panel 3.
is supplied to the segment side. On the other hand, a signal synchronized with these signals is supplied to the digit driver 4. A plasma display panel performs display by utilizing the fact that only segments to which a signal on the segment side and a signal on the digit side are applied simultaneously emit light by discharge. In FIG. 1, each segment of the plasma display panel,
Strictly speaking, the discharge starting voltages of 5a, 5b, .

Furthermore, if the frequency is constant, the discharge start voltage of the segment increases with the usage time, and the discharge start voltage of the driver 2,
The segments whose voltage has become higher than the voltage supplied from 4 will no longer be discharged. The rate of increase in this discharge starting voltage is proportional to the number of pulses (actual frequency) applied to the segment.
This situation is shown in Figure 2. FIG. 3 is a block diagram of a plasma display device according to the present invention. The 7 segment decoder, segment driver 2, digit driver 4 and display segment 5 are exactly the same as the conventional one shown in FIG. 2, but in the plasma display panel 3,
An alarm segment 6 different from the display is provided, and drivers 7 and 8 are provided for driving this segment.
is newly added.

Next, we will discuss the role of the alarm segment 6 in the plasma display panel and the drivers 7 and 8 for driving it. The alarm segment 6 is manufactured using the same manufacturing method as the other display segments 5 in the plasma display panel, and has the same characteristics as the firing voltage and the fluctuation of the firing voltage. Discharge of the display segment and alarm segment starts when a high frequency wave having a frequency twice that of the voltage applied to the display cell and the same voltage as the display cell is applied to the alarm segment 6 via the drive circuits 7 and 8. Figure 4 shows the voltage change over time. According to FIG. 4, the voltage applied to the display segment and the alarm segment is 150V, and the frequency of the voltage applied to the alarm segment 6 is twice that of that applied to the display segment. Therefore, the alarm segment is A
It can be seen that the display cell reaches the end of its life at point B, that is, reaches a state where it does not emit light. Point A is always on the shorter-life side than point B, and an observer of a device in which a plasma display panel with such an alarm segment is used,
Depending on whether or not the alarm segment emits light, it is possible to determine whether or not the operating state of the display segment is normal. In other words, in this device, if the alarm segment operates normally, then the display segment is operating normally, and if the alarm segment does not discharge and emit light, it is possible that the display segment is operating abnormally. The observer can then check the display.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional plasma display device, FIG. 2 is a diagram showing changes over time in the firing voltage of the display segment of FIG. 1, and FIG. 3 is a diagram showing a first embodiment of the present invention. The block diagram, FIG. 4, is a diagram for explaining the characteristics of FIG. 3. Younger brother' figure Younger brother Z figure 3 figure 4

Claims (1)

[Claims] 1. In a plasma display device equipped with a first display electrode that displays characters, numbers, symbols, etc. by selectively driving a plurality of electrodes in accordance with an input signal, the plasma display device is constantly driven when the plasma display device is driven. The second
a display electrode is provided independently of the first display electrode, and the drive voltage of the first and second display electrodes is the same, and the drive frequency of the second display electrode is set to the drive frequency of the first display electrode. A plasma display device with an alarm display, characterized in that the frequency is set to be higher than that of the second display electrode so that the life of the second display electrode is shorter than the life of the first display electrode.