JPH01177076A - Display device - Google Patents

Abstract

PURPOSE:To curtail unnecessary power at the holding time when no display signal is inputted, and also, to raise the safety of the device by stopping an output of a driving voltage generating means, when a synchronizing signal is not inputted to a control means. CONSTITUTION:An external synchronizing signal detecting circuit 70 checks whether a synchronizing signal H and V inputted to a timing generating circuit 50 from the outside exist or not, and when these synchronizing signals are not inputted, a control signal for stopping a high voltage output of a DC/DC converter 60 is outputted. Accordingly, at the holding time when the synchronizing signal is not inputted to the timing signal generating circuit 50, the DC/DC converter 60 does not generate a high voltage for driving a display panel. In such a way, an unnecessary power consumption is curtailed, and also, the safety of the device is raised.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a display device, and in particular, to an improvement of a peripheral drive circuit in a display device that operates optically by applying a relatively high drive voltage. .

<Prior art> EL (electroluminescence) is a display device that operates optically by applying a relatively high voltage.
Display devices, plasma display devices, etc. exist. In these display devices, the configurations of peripheral drive voltage application means and control means are similar to each other. Therefore, although a thin film EL display device is exemplified in the following description, the present invention is not limited to this.

Conventionally, in the peripheral drive circuit of a thin-film EL display device, 5 volts and 15 volts are input as an external power source, and an internal DC/DC converter generates the high driving voltage necessary for the EL display panel to emit light. ing. and,
The driving high voltage is selectively applied to a plurality of electrodes of the display panel based on input signals including display data, transfer lock, horizontal synchronization signal, vertical synchronization signal, etc.

<Problem to be solved by the invention> Conventionally, a DC/DC converter outputs the high voltage necessary to drive an EL display panel regardless of the input signal as long as the power is turned on. Power is wasted even when the device is in standby mode. Further, it is not preferable from a safety standpoint to output a high voltage when no display is being displayed.

Therefore, the present invention provides DC/DC when there is no signal input.
It is an object of the present invention to provide a highly safe display device that can reduce power consumption in a standby state by stopping high voltage output of a converter.

Means for Solving Problems> A display device according to the present invention includes a display panel that operates optically by applying a drive voltage, and a driver for selectively transmitting the drive voltage to a plurality of electrodes of the display panel. means, a driving voltage generating means for generating a driving voltage, a switching means for inputting an output from the driving voltage generating means to the driver means, and controlling the driver means and the switching means based on an input signal including display data and a synchronization signal. and a synchronization signal detection means for stopping the output of the drive voltage generation means when the synchronization signal is not input to the control means.

<Operation of the invention> The synchronizing signal generating means detects whether or not an input signal is input to the control means, and operates the drive voltage generating means when the synchronizing signal is input, but when the synchronizing signal is not input. In the standby state, the output of the drive voltage generating means is stopped. Thereby, the power consumption of the display device can be reduced and the safety of the device can be improved.

<Embodiment of the Invention> The drawing is a block diagram schematically showing a thin film EL display device according to an embodiment of the present invention. In the figure, a thin film EL display panel 10 includes a plurality of electrodes in the X direction and the X direction, and a voltage of 190 volts or more is applied to the pixels at the intersections of the electrodes in the X direction. This causes the light to emit light. The driver IC (integrated circuit) transmits a driving voltage to the electrodes in the X direction, and the driver IC 30 transmits the driving voltage to the electrodes in the X direction. Those driver IC20,30
consists of high-voltage switching elements and logic circuits such as shift registers and latch circuits. The high voltage switching circuit 40 applies a high voltage pulse for driving the display panel to the power supply lines of the driver ICs 20 and 30. 5
The timing signal generation circuit 50 that operates with volt input is
To generate timing signals for line sequential driving from four types of input signals: display data DIN, transfer lock CKD, horizontal synchronization signal H9, vertical synchronization signal V, and thereby control the high voltage switching circuit 40 and driver ICs 20 and 30. This is a logic circuit. The DC/DC converter 60 for high voltage generation generates a modulation voltage v1 of 60 volts for distinguishing between light emitting and non-emitting EL pixels from an input of 15 volts. l
is converted into a write voltage vw of 190 volts required for light emission. This DC/DC converter 60 has a function of stopping the voltage conversion operation using a logic level control signal.

The external synchronization signal detection circuit 70 checks the presence or absence of synchronization signals H and V externally input to the timing generation circuit 50, and when these synchronization signals are not input, the DC/
A control signal for stopping the high voltage output of the DC converter 60 is output. As a result, the EL according to this embodiment
In display devices, during standby when no synchronization signal is input to the timing signal generation circuit 50, the DC/DC converter 60 does not generate high voltage for driving the display panel, which reduces unnecessary power consumption and improves the safety of the device. Sexuality is enhanced.

<Effects of the Invention> As described above, according to the present invention, it is possible to provide a display device that can reduce unnecessary power during standby when no display signal is input and can improve the safety of the device.

[Brief explanation of the drawing]

The drawing shows a schematic block diagram of an EL display device according to an embodiment of the present invention. In the figure, 1o is a thin film EL display panel, 2° and 30 are driver ICs, 40 is a high voltage switching circuit, 5o is a timing signal generation circuit, and 6o is a DC/DC converter for high voltage generation.
a DC converter, and 70 an external synchronization signal detection circuit.

Claims (1)

[Scope of Claims] A display device comprising: a display panel that operates optically by applying a drive voltage; driver means for selectively transmitting the drive voltage to electrodes of the display panel; a driving voltage generating means for generating a voltage; a switching means for inputting an output from the driving voltage generating means to the driver means; and controlling the driver means and the switching means based on an input signal including display data and a synchronization signal. A display device comprising: a control means; and a synchronization signal detection means for stopping the output of the drive voltage generation means when the synchronization signal is not input to the control means.