Multiple message selective telltale display

In an instrument panel having a display area sufficient to display only one telltale message at a time, apparatus for selectively showing any one of a plurality of telltale messages on the display area comprising:

• a plurality of optical projectors each for projecting a message onto the display area;
• each optical projector comprising a message image transparency, a lamp for illuminating the transparency, and optics for projecting a message onto the display area, wherein the lamps are assigned an order of priority;
• control means for prompting message display, wherein more than one message at a time may be prompted and the control means is coupled to a high voltage side of each lamp to selectively apply energizing voltage to each lamp;
• and
• a logic circuit coupled to the lamps and responsive to the control means for selectively energizing the lamps for displaying prompted messages one at a time, the logic circuit comprising means for coupling a low voltage side of a highest priority lamp to ground and a diode in series with a low voltage side of a lower priority lamp and coupled to the low voltage side of the highest priority lamp, whereby the diode is nonconductive to prevent energization of the lower priority lamp when the highest priority lamp is energized.

In an instrument panel having a display area sufficient to display only one telltale message at a time, apparatus for selectively showing any one of a plurality of telltale messages on the display area comprising:

• a plurality of optical projectors each for projecting a message onto the display area;
• each optical projector comprising a message image transparency, a lamp for illuminating the transparency, and optics for projecting a message onto the display area, wherein the lamps are assigned an order of priority;
• control means for prompting message display, wherein more than one message at a time may be prompted and the control means is coupled to a high voltage side of each lamp to selectively apply energizing voltage to each lamp;
• and
• a logic circuit coupled to the lamps and responsive to the control means for selectively energizing the lamps for displaying prompted messages one at a time, the logic circuit comprising diode means serially connected at a low voltage side of lamps other than the highest priority lamp for preventing conduction in lamps of lower priority than any energized lamp.

In an instrument panel having a display area sufficient to display only one telltale message at a time, apparatus for selectively showing any one of a plurality of telltale messages on the display area comprising:

• a plurality of optical projectors each for projecting a message onto the display area;
• each optical projector comprising a message image transparency, a lamp for illuminating the transparency, and optics for projecting a message onto the display area, wherein the lamps are assigned an order of priority;
• a constant current source to regulate lamp current;
• control means for prompting message display, wherein more than one message at a time may be prompted;
• and
• a logic circuit coupled to the lamps and responsive to the control means for selectively energizing the lamps for displaying prompted messages one at a time, wherein the lamps are connected in parallel paths between the control means and the current source, each path including a lamp and one or more diodes in series with the respective lamp other than the highest priority lamp with the number of diodes increasing for decreasing priority, so that the conduction of any lamp above lowest priority prevents conduction through the diodes of lower priority lamps.