Digital tuning FM stereophonic receiver including phase locked loop synthesizer
AssigneePioneer Electronic Corporation
InventorsAkira Misawa, Tatsuo Numata
Life of this patent
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Abstract
A digital tuning FM stereophonic receiver of the type including a phase locked loop synthesizer. A digital code generating circuit is provided for generating a digital code which consists of several bits to be applied to a programmable frequency divider inserted in the phase locked loop. At least one auxiliary bit is provided together with the bits of the digital code. The information of the auxiliary bit is used to input and hold the digital code to be applied thereto. Muting operation of the FM stereophonic receiver is controlled in accordance with the information of the auxiliary bit.
Claims10
In a digital tuning FM stereophonic receiver of the type including a programmable frequency divider employed in a phase locked loop synthesizer wherein a digital code is provided in order to determine a frequency division number of said programmable frequency divider, the improvement comprising:
- (a) coded means carrying a plurality of arrays of code-indicating indicia;
- (b) first detecting means for detecting the digital code represented by each array of indicia when in alignment therewith;
- (c) latch means for storing the detected digital code in response to a latch control signal, the output of said latch means being connected to said programmable frequency divider, and the stored digital code remaining in said latch until a subsequent latch control signal is received;
- (d) alignment indicating means carried on said coded means;
- (e) second detecting means for providing an alignment output signal when aligned with said alignment indicating means, an alignment output signal from said second detecting means indicating that said first detecting means is aligned with one of said arrays of code-indicating indicia;
- and
- (f) means for generating said latch control signal in response to said alignment output signal.
Dependencies are inferred from the claim text.