Display screen blanking using interactive video and user-interface monitoring

An apparatus for controlling video display comprising:

• user-activity means connected to a user device for generating an output having a first logic state indicative of activity by said user device and having a second logic state indicative of inactivity by said user device;
• video-activity means connected to video circuitry for generating an output having a first logic state indicative of selected activity by said video circuitry and having a second logic state indicative of inactivity;
• a first timer having a reset connected to said user-activity means to reset said first timer in response to said first logic state being output by said user-activity means, said first timer having means for generating a first time-elapsed signal upon passage of a selected time interval between successive resets;
• a second timer having a reset connected to said video-activity means to reset said second timer in response to said first logic state being output by said video-activity means, said second timer having means for generating a set signal upon passage of a selected time interval between successive resets;
• latch means having a set input connected to said second timer for generating a second time-elapsed signal in response to receiving said set signal from said second timer, said latch means having a reset in electrical communication with said user-activity means to terminate said second time-elapsed signal in response to said first logic state being output by said user-activity means;
• and
• means connected to said first timer and said latch for reducing power consumption by a display device during time periods of simultaneous receipt of each of said first and second time-elapsed signals.

A method of reducing power consumption by a display device comprising:

• monitoring time intervals between successive uses of at least one user-interface device of a computing system;
• initiating a first time-elapsed signal when a time interval between successive uses exceeds a first predetermined time period;
• terminating said first time-elapsed signal only upon a subsequent use of a user-interface device;
• monitoring time intervals between successive updates by video update circuitry;
• initiating a second time-elapsed signal when a time interval between successive updates by said video update circuitry exceeds a second predetermined time period;
• terminating said second time-elapse signal only upon a subsequent use of a user-interface device;
• and
• generating an interrupt signal for reducing power consumption by a display device during time periods in which each of said first and second time-elapsed signals is being generated.