JPS6043693A - Display panel driving system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a display panel such as an ice plate driven by AC pulses.

Conventionally, the driving power for these display boards was AC commercial power.
Obtain the required drive pulses through a transformer and switching circuit. This has been achieved by a so-called AC-AC converter method, or a so-called DC-AC converter method in which the required drive is obtained through a transformer, a rectifier circuit, and a switching circuit.

In such a system, a transformer is required to obtain the entire driving current, which has the drawback of increasing the weight, size, and cost of the driving power source.

The present invention improves these drawbacks by increasing the voltage peak value and frequency of the AC commercial power source to the values necessary for driving the display panel, thereby obtaining a desired driving power source without using a transformer.

The details of the present invention will be explained below with reference to Examples.

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a waveform diagram of each part obtained from FIG. 1.

In FIG. 1, the frequency of the AC commercial power source 1 is 56 Hz or 60 Hz, and the voltage peak value (absolute value) is about 140 V, and as it is, it is impossible to practically light up the display board. In general, the voltage peak value and frequency (effective frequency) for lighting the display board in a bright manner that can be used for practical purposes.
are respectively 150~300V, 2~20KH2"t'
, sru.

A first diode 3 and a second diode 3' are connected to an AC commercial power source 1 via a first capacitor 2 and a second capacitor 2', respectively. AC commercial power supply 1
The voltages after the output of the first and second capacitors 2.2', that is, the voltages Bt and Em between the terminals of the first and second diodes 3.3' are as shown in Figures 2a and 2b, respectively. It will be like this. Now, the voltage peak value of AC commercial power supply 1 is A,
If the angular velocity is wt, Ex and Es are respectively,
・-F21=Asin wt-1-A Eg=Asin
It is expressed as wt −A. At this time, the capacitances of the first and second capacitors 2.degree. 2' are selected to a value that can sufficiently supply a high frequency pulse current due to switching, which will be described later, to the display panel 5 serving as a load. The voltage E8 between the output terminals of each of the first and second capacitors 2, 2' is expressed as the difference between El and Ez, and its value is Es ==E1-Em =(As in wt-1-A
) −(As i'n wt −A)=2A.

In other words, the voltage is essentially 2 of the voltage peak value of the AC commercial power supply.
You can get double the DC power.

The above-described substantial DC power source is switched at high frequency by the switching circuit 4, and its output is a high frequency pulsed power source as shown in FIG. 2C, thereby driving the display panel 5. The voltage peak value of high-frequency pulsed power supply is twice that of AC commercial power supply, or about 28
0V, for example, the frequency of the high frequency pulse is 21oKHz.
By setting each constant of the switching circuit 4 so as to achieve the desired brightness, the display panel 5 can be lit with sufficient brightness for practical use.

The switching circuit 4 may be a normal oscillation circuit, for example, as shown in FIG. It is sufficient to set the values of the circuit constants.

As described above, according to the present invention, the electric potential of each AC commercial power source is converted into positive and negative electric potential by the peak voltage of each AC commercial power source by two pairs of capacitors and diodes, that is, the difference potential between each power source. A substantial DC power source with a voltage twice the peak voltage of an AC commercial power source is obtained, and this is converted into high frequency pulses in a switching circuit using normal self-excitation, and external 1 is used as a release discharge display board, an AC type EI, and a display. The entire display panel, which is driven by AC pulses, is driven. Therefore, it is possible to provide a light, compact, and inexpensive display board drive power source without using any transformers.

In addition, in Embodiment 2, resistors, capacitors,
Of course, addition and modification of all electric elements such as inductors are included in the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 (
al~(C1 shows the waveform diagram of the driving power source obtained from FIG. 1. In the figure, 1... AC commercial power source, 2.2'...
...first and second capacitors, 3 and 3' are the first
and a second diode, 4 is a switching circuit, and 5 is a display board.

Claims (1)

[Claims] A first diode is connected to an AC commercial power source through a first capacitor, and a second diode is connected through a second capacitor, and the first and second diodes are connected so that they have opposite polarities. By this, each of the first and second capacitor output terminal potentials of the AC commercial power source is 2.
With respect to the potential at the other end of the hC commercial power supply, the potential is changed so that it is always positive or always negative, and the potential between the first and second capacitor output terminals is constantly adjusted to the AC power supply.
The potential value is converted into a frequency pulse by a means for maintaining the peak-to-peak potential value of the commercial power supply, and a switching circuit that performs a high-frequency switching operation on the power source, which is constantly maintained at the P-P potential value of the AC commercial power supply. is steady L/c
A display board driving method characterized in that an AC type display board is driven by an AC commercial power source that has been converted into a high-frequency AC power source with a peak-to-peak potential value of an AC commercial power source.