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Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2002-Feb-07

Publishing Venue


Related People

Joseph Patina Henry Bogut Daniel Nigro


Presently, option class recognition schemes (selec- LED. The existing electrical option select scheme uses tion of external speaker, external microphone, external 2 lines that select between a digital 00, 01, 10, or 11. RE . .) use electrical connections. The problem with this This optical scheme offers the same capabiity of selecting scheme is that as accessories increase, so do the nom- digital 00, 01, 10, or 11, but does so through one exter- ber of lies necessary to select them. An alternative to nal path, a light pipe instead of multiple electrical con- this method would be to use an option select scheme nections. The scheme uses the fact that given LEDs have that utilizes an optical interconnect. The accessory would a spectral distribution that allows for distinguishing select the correct option class by selecting the correspond- between LEDs. The different frequency LEDs are fed ing frequency LEDs that need to be lit. For example: if into a light pipe that channels the light into the radio a 2 bit option class scheme is necessary, the accessory through the light pipe port. The light is then passed would select between 2 LEDs, using LED1 as a 950 nm through filters that pass only one given frequency LED LED and LED2 as a 850 nm LED for example. This and the photo detector determikes if that kquency LED allows for the two existing option select lines and their has been lit in the accessory. In this fashion, the photo associated static protection and filtering circuitry to be detectors set the digital 0 or 1 information into the deleted. The circuit shown below shows such a 2 bit microprocessor dependent upon the status of the LED implementation. However the circuit can be further in the accessory. expanded to include additional bits, such as a 660 nm BLOCK DIAGRAM (Example of 2 bit implementation) ACCESSORY I I RADIO I a OPT1ON q + MICRO- PROCESSOR CR1 set at freq 1 CR2 set at freq 2 filter 1 passes freq 1 filter 2 passes freq 2 l-, GROUND 0 Motorola. Inc. 1993 47