Importance

Loading Importance Indicators...

Abstract

When a 'screen saver' operates to display a homogeneous black picture image after the same image is continuously displayed on a CRT for a predetermined period of time, a power supply for a CRT display unit is controlled to be turned off, thereby preventing the CRT display unit from being left for a long time in a power-on state. Namely, a waiting time of 3 minutes, for example, is provided when the 'screen saver' operates so that the CRT displays a homogeneous black picture image to turn off a power circuit for the CRT, and then a heater for the CRT is turned off after a lapse of a predetermined period of time of 5 to 60 minutes, for example. An extension graphics board, which is inserted in an open slot provided in a computer of an open architecture type may be provided to perform this function. The extension graphics board has an input detection part including a keyboard access detection part for detecting an address signal which is supplied to an address bus in response to manipulation of a keyboard, and an interruption request detection part for detecting an interruption signal which is output in response to manipulation of a mouse. A timer is reset when the input detection part detects the presence of an input signal received from the keyboard or the mouse. When no reset signal is supplied from the input detection part again before a lapse of a period of time which is previously set in the timer, a blank signal is supplied to the CRT display unit.

Loading the Abstract Image...

First Claim