JPS61213894A - El element driver - 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 [Technical Field] The present invention relates to an EL (electroluminescence) element driving device, and in particular, to
The present invention relates to an element driving device that enables lcEL display.

[Prior art]

Conventionally known EL has been used for illumination. Recently, it has also been adopted for displaying other segments. Since currently known EL elements are mainly AC driven, a circuit configuration capable of switching an AC signal is used to control the blinking of the EL upper segment. An example of such a configuration was the one shown in FIG.

In the figure, AC switching circuits 8WA1-4 are interposed between the EL driving AC power source and each of the plurality of segment electrodes 5E01-4 of the EL element ELD. An on-off control signal 5CN-F is individually supplied to control the on/off state of each of these AC switching circuits 5WA1 to 5WA4. For example, in the case of 8CR, the on-off control signal 5CN-F is a firing signal applied to its gate electrode. In addition,
The AC switching circuit is composed of mechanical switches such as relays, semiconductor switches such as transistors, and the like.

However, these AC switching circuits
In order to switch the AC voltage for driving the L, the number of element parts was large, and the circuit configuration was complicated. Therefore, there were problems in that the reliability of the circuit decreased and the device became larger and more expensive.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems.
1 circuit configuration is simple, reliable and highly reliable.

It is an object of the present invention to provide a small and inexpensive EL element driving device.

〔Example〕

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the present invention. In addition, here, EL
It is assumed that elements EI and D have two segment electrodes.

In FIG. 1, individual control signals C0N1 and CON2 are used to control on and off of the EL segment display.
are supplied to phase switching circuits 8WC1 and swc2, respectively.

The output voltages BaN and Ecx of these phase switching circuits 5WC1 and swc2 are supplied to DC switching circuits DC8W1 and DC8W2, respectively, and their output voltages Esw and law are applied to the segment electrodes 5EG1 and 5EG2 of the EL element ELD. has been done.

The pulse signal CNP generated from the pulse generator PG for alternating current is transmitted through two phase switching circuits swc1.
, swc2 and the DCC switch footpath DC8W3. The output voltage Esw3 of this DCC switch footpath DC8W3 is applied to the EL element ELD.
is supplied to the common electrode COM.

The operating voltage DCV (for example, 140V) of the three DC switching circuits DC8W1 to DC8W3 is supplied from the high voltage DC power supply P8L.

FIG. 2 shows a more detailed circuit configuration of FIG. As shown in the figure, the DC switching circuit Dcswi~3 consists of a switching transistor and its associated resistor. The phase switching circuits 5WC1 and 5WC2 are composed of exclusive OR gates. Further, the high-voltage DC power supply PAL rectifies AC 10 (l) of the commercial power supply.

FIGS. 3(a) to 3(el) show the operation of each part in the apparatus according to the embodiment of the present invention.

Hereinafter, reference will be made to FIGS. 1 to 3.

Assume that the control signal C0N1 for controlling the on/off of the EL display is at a "high" level, and the other control signal CON2 is at a "low" level.

It is assumed that the pulse signal CNP with a duty ratio of approximately 50:50 is continuously generated from the pulse generator PG.

Therefore, the first phase switching circuit 8WC1 generates an output voltage EC)l which repeats high, low, and EL in the opposite phase to the pulse signal CNP.

On the other hand, the pulse signal C is output from the second phase switching circuit swc2.
An output voltage ECN, which is in phase with NP, is generated.

Next, look at the output voltages Esw, ~Bsw, of the three DC switching circuits DC8W1 to DC8W3.

Output voltage RaH of the first phase switching circuit swc1.

Since the output voltage ECN2 of the second phase switching circuit swc2 and the output voltage ECN2 of the second phase switching circuit swc2 are in opposite phase, both output voltages of the two DC switching circuits DC8W1 and DC8W2 are also in opposite phase. The waveform is as shown in (a), and the other output voltage Esw is as shown in [cJ] in the figure.

Further, the third DC switching circuit DC8W3 is also driven by the pulse signal CNP, and is in phase with the pulse signal GNP and is "high" at the amplitude @V.

Generates an output voltage E8W3 that takes a “low” level (third
(See figure (b)).

Therefore, both segment electrodes 5Ee1 of the EL element ELD
and 5EG2 has both output voltages Egw as the first signal.
, and Bsw are applied. Further, the output voltage E5W3 (third
(see figure (b)) is applied. First segment electrode 8E
The potential difference Eg-a between G1 and the common electrode COM is the third
As shown in Figure (d), the level is "high" and @low between "1+v" and "1-v". However, the potential difference E8 between the second segment electrode 8EG2 and the common electrode COM -G becomes O as shown in FIG. 3(e).

Therefore, the first segment electrode 5gG1 of the EL element ELD
, sufficient energy to energize the display (potential difference 2V)
is supplied and the display lights up. However, since sufficient energy for display activation is not supplied to the second segment electrode 8EG2 (potential difference O)
.

Remains off.

In this way, in one embodiment of the present invention, the EL element ELD
Since a DC switching circuit using high-voltage DC switching elements (transistors, FETs, etc.) is used to control the lighting and extinguishment of lights, it is highly reliable, noiseless, compact, and low cost compared to switching elements such as mechanical relays. SCB
It can be produced at a lower cost than other AC switching elements such as . Furthermore, compared to configuring an AC switching circuit using a plurality of DC switching elements, it has advantages such as simple configuration, low power consumption, and low cost.

Incidentally, the brightness can be easily adjusted by changing the repetition frequency of the pulse generator PGK and the chivalrous signal CNP.

Furthermore, in the above-mentioned embodiment, the EL element ELD has two segment electrodes, but more than two segment electrodes may be used.

Control signal 1 phase switching circuit and DC corresponding to each
Of course, it is sufficient to provide a switching circuit.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to realize an ELL child drive device with a simple configuration, high reliability, and low cost.

[Brief explanation of the drawing]

FIGS. 1 and 2 are block diagrams showing the circuit configuration of an ELL child drive device according to an embodiment of the present invention, and FIGS.
Te) is a signal waveform diagram showing the operation of the device according to the embodiment of the present invention, and FIG. 4 is a configuration block diagram showing the conventional example. ELD...EL element 5EG1.5BG2...Segment electrode COM
......Common electrode DC8W1-3...D, C switching circuit s
wc1. swc2... Phase switching circuit PSL...
...High voltage DC power supply C0N1, CON2... Control signal GNP...
...Pulse signal 8WA...AC switching circuit E s w,
, E sw, ・Voltage applied to the upper segment electrode of the old EL element E sws... Voltage applied to the common electrode of the EL element Fig. 7 Fig. 3

Claims (3)

[Claims] (1) EL having a plurality of segment electrodes and at least one common electrode, and capable of performing EL display individually between each of the plurality of segment electrodes and the common electrode
a first signal means for supplying a first signal to each of the plurality of segment electrodes; a second signal means for supplying a second signal to the common electrode; a first signal for generating a desired energy between the first signal and the second signal with respect to the first electrode;
The present invention is characterized by comprising a control means and a second control means for preventing energy required for energization from occurring between the first signal and the second signal for segment electrodes that do not perform display energization. EL element driving device. (2) The first control means is configured to control the first signal and the second signal to be pulse signals having the same predetermined amplitude and to have opposite phases to each other. EL element driving device according to scope 1. (3) A patent characterized in that the second control means is configured to control the first signal and the second signal to be pulse signals having the same predetermined amplitude so that both pulses are in phase. An EL element driving device according to claim 1.