Communications: electrical – Visual indication – Using light emitting diodes
Reexamination Certificate
2000-03-01
2001-07-24
Hofsass, Jeffrey (Department: 2632)
Communications: electrical
Visual indication
Using light emitting diodes
C340S691100, C340S691400
Reexamination Certificate
active
06265985
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to a display apparatus, and more particularly to an apparatus for controlling two visual indicators with a single output pin of an integrated circuit, an illumination condition of one the visual indicators being dependent on an illumination condition of the other visual indicator.
BACKGROUND OF THE INVENTION
In a conventional display apparatus including two independent visual indicators, each indicator is independently driven using separate integrated circuit pins and separate current limiting resistors. This type of conventional display apparatus is problematic in that it is “pin constrained”. In other words, an excessively large number of integrated circuit pins are required to drive a large scale display apparatus. Notably each additional pin in an application specific integrated circuit has a tangible cost associated with it. In other words, each additional pin required to drive the visual indicators eliminates other possible functions or forces the use of a larger and more expensive integrated circuit package.
Moreover, conventional display apparatus require that a separate current limiting resistor be provided for each independently driven visual indicator. This is problematic in that it increases the scale of the display apparatus.
Accordingly, a primary object of the present invention is to provide an improved display apparatus in which a only single integrated circuit output pin is needed to selectively drive two dependent visual indicators.
Another object of the present invention is to provide such an improved display apparatus in which a single current limiting resistor is used to drive two independent visual indicators, thereby reducing the size of the display apparatus relative to many conventional display apparatus.
REFERENCES:
patent: 4924177 (1990-05-01), Mulz
patent: 5359290 (1994-10-01), Cervas
patent: 6037874 (2000-03-01), Heironimus
Hewlett--Packard Company
Hofsass Jeffrey
Nguyen Phung T
LandOfFree
Method and apparatus for controlling two dependent visual... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for controlling two dependent visual..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for controlling two dependent visual... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2496391