JPH03214591A - Integrated circuit power supply device for electro-luminescence driving - Google Patents

Abstract

PURPOSE:To simplify circuit configuration and emit light with specified brightness by furnishing a semiconductor drive circuit and an externally excited oscillator circuit capable of freely varying the oscillation frequency, and providing a pulse generator and rectifier circuit. CONSTITUTION:A DC voltage V is obtained at the C, D ends of a rectifier circuit 1. When drive signals DV1-DV4 are applied form a pulse generator 8 to driver circuits 2-5 due to switching element such as power transistor in such a phase relationship as shown in the attached illustration, a voltage waveform as shown in the illustration is applied between the terminals E, F of an electroluminescence element 6. Thus light emission is made. The brightness of the EL 6 is adjustable through varying the oscillation frequency. Thereby brightness adjustment of EL 6 is made easier, and wiring is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lightweight and thin power supply device for emitting light from a large electroluminescent element (hereinafter referred to as EL), which is used for advertising panels that require brightness adjustment or for driving power supplies. Various interior products that require little installation space,
It is effective for use with other display devices. (Prior art) A power source for emitting light from an EL, especially a large EL, requires a transformer with winding specifications according to the area of the EL, which limits the overall shape of the power supply and reduces its weight. Furthermore, it was practically impossible to vary the frequency due to heat generation, even with a transformer using an expensive iron core with low core loss.

To solve this problem, a transformerless light emitting device has been proposed as in Japanese Patent Application Laid-Open No. 63-37591, which consists of a transistor drive circuit, a capacitor series charging circuit, and a distribution control circuit consisting of an oscillation circuit, a binary counter, and a divider. However, this circuit requires many circuit elements and the circuit itself is complex, so it has the disadvantage of requiring a large area for production.

(Purpose) The present invention provides a power supply device that does not use a transformer, can be freely designed, has a simple circuit configuration, and can emit large EL with desired brightness when connected to a commercial AC power source. That is. The present invention also provides a power supply device compatible with a DC low voltage source.

(Ellipsis) The device of the present invention includes a semiconductor drive circuit, a separately excited oscillation circuit whose oscillation frequency can be freely varied, a pulse generator, and a rectifier circuit. Further, a device compatible with a DC low voltage power supply includes an inverter, a Kotscroft type booster circuit, an oscillation circuit equipped with an oscillation frequency adjustment means, a pulse generator, and a drive circuit.

None of the above devices require an output winding transformer. In the device of the present invention, the EL drive circuit is a switching circuit using a power transistor or the like, and the oscillation circuit is a separately excited oscillation circuit that can freely vary the oscillation frequency.

(Effects) These facilitate the brightness adjustment of the EL, suppress the heat generation of the entire device to a low level, allow installation near the EL panel, and simplify wiring. Furthermore, since the device of the present invention can be configured in the form of a plate or a thin block,
It has a greater degree of freedom in design, making it easier to design small and lightweight power supplies. In addition, since there is no coil, the output voltage and frequency hardly change regardless of the size of the EL capacity, so various E
It can also be used as an experimental evaluation power source that drives L in parallel.

(Embodiment 1) Figure 1 shows a circuit using a 100V commercial AC power source as the primary power source, and a DC voltage of approximately 140V is obtained at terminals C and D of the rectifier circuit (1). (2>(3), (4), and (5) are power. Drive circuits using switching elements such as transistors, and (6) are EL.

(7) is an oscillation circuit equipped with oscillation wave number adjustment means (7a), and (8) is a pulse generator.

The equivalent circuit of EL is as shown in Figure 3 and is capacitive, so when a drive signal is added from the pulse generator (8) with the phase relationship as shown in Figure 2, the voltage between EL terminals E and F increases. A voltage waveform as shown in the figure is applied to the light, and light is emitted.

The luminance of the EL can be adjusted by varying the oscillation frequency of the oscillation circuit (7). The above power supply device can cause an EL panel with an area of 3000 crA to emit light with an output voltage of 106 V, and the frequency can be varied between 250 and 900 Hz. Note that by selecting a power transistor with a high output as the switching element, a larger panel can be made to emit light at a higher wave number.

(Embodiment 2) FIG. 4 shows an example in which the drive circuit of FIG.
1, V2 is a voltage obtained by rectifying a commercial power supply of 100 V, and has 172 switching elements.

That is, when the switching elements <4) (5) are driven by the respective drive signals, V 1 is applied to the terminal of E L (6).
, ■2 are applied alternately and V1=v2=■, a waveform between E and F in FIG. 2 is obtained.

(Embodiment 3) FIG. 5 is a circuit diagram when a low-voltage DC power supply is used as the primary power supply, and the inverter (10) is a CMO shown in FIG.
It is integrated into an IC using an S oscillation circuit.

(11) is an inverter buffer, and (12) is a buffer. A voltage waveform as shown in FIG. 7 is obtained between J and K, and the inverter buffer and buffer drive the Kotskofloft circuit (13). As a result, n times higher DC voltage is generated between CD and D of the drive circuit, and by driving each switching element as in the case of FIG. 1, a rectangular wave is generated between E and F. It is possible to cause EL to emit light.

Also, SW1, SW, P. NP transistor, SW2
, SW 4 are configured with NPN} transistors, and DV. Instead of driving SW1 from point Q through a resistor, SW
, is driven from point P through a resistor, then
Since it is only necessary to supply pulses with a phase difference of 180° in place of D2 and D V4, the circuit can be further simplified. In the above circuit, the oscillation circuit (7) is a circuit similar to that shown in FIG. 6, and the luminance of the EL can be varied by varying the resistance R.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of the device of the present invention using an AC power supply, Figure 2 is a diagram showing the drive waveform of the switching element and the voltage waveform between the EL terminals, Figure 3 is the equivalent circuit of the EL element, and Figure 4 is the drive A circuit diagram showing another example of the circuit, Fig. 5 is a circuit diagram when using a DC power supply, Fig. 6 is a circuit diagram of an inverter, and Fig. 7 is a circuit diagram showing another example of the circuit.
The figure is a voltage waveform diagram at the inverter output end. (2), (3), (4), and (5) are switching elements of the drive circuit. (6) is EL

Claims (2)

[Claims] (1) An EL drive IC power supply device comprising a semiconductor drive circuit, a passive oscillation circuit whose oscillation frequency can be freely varied, a pulse generator, and a rectifier circuit. (2) An IC power supply device for driving EL comprising an inverter, a Kotscroft type booster circuit, an oscillation circuit equipped with oscillation frequency adjustment means, a pulse generator, and a drive circuit.