Dual-Tuner Broadcast Receiver PLL Control for PIP Interference
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Solution Overview
Problem
Broadcasting receivers with picture-in-picture (PIP) functions experience interference between main and sub tuners, affecting performance, and existing solutions complicate system design and increase costs by requiring additional components to manage power supply.
Innovation Solution
A broadcasting receiver with multiple tuners and an interference controller that adjusts PLL data to separate frequency bandwidths between main and sub tuners, reducing interference by controlling oscillation frequencies and selecting non-interfering channels when the PIP function is off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple tuners are used to enable picture-in-picture function, then the broadcasting receiver can simultaneously display multiple channels, but frequency interference occurs between the main tuner and sub tuner
Solution Approach 1:
The patent changes the oscillation frequency parameter of the sub tuner by loading different PLL data when PIP function is inactive, separating its frequency from the main tuner's frequency to eliminate interference while maintaining the capability to display multiple channels when needed
2Object-affected harmful factors
If additional components are added to control power supply of tuners, then frequency interference can be managed, but system complexity and cost increase
Solution Approach 1:
The patent makes the sub tuner self-adjusting by automatically loading appropriate PLL data based on whether PIP function is active, eliminating the need for external power supply control components and reducing system complexity while effectively managing frequency interference
Solution Approach 2:
The patent pre-stores multiple sets of PLL data with different oscillation frequencies, allowing the sub tuner to quickly switch to a non-interfering frequency configuration when PIP function is inactive, preventing interference before it occurs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively reduces or prevents frequency interference between main and sub tuners, improving picture quality without adding complex components or increasing costs, allowing simultaneous display of multiple channels on a single screen.
Implementation Method 1
a tuner selects a radio frequency (RF) signal of a desired channel among RF signals received from an antenna and converts the selected RF signal into a intermediate frequency (IF) signal
Implementation Method 2
a demodulator demodulates the IF signal
Implementation Method 3
an interference controller configured to read data used to control oscillation frequencies for respective channels to select a specific channel with reference to a channel frequency of a currently selected and displayed broadcasting signal and operate at least one other tuner according to the read data
Data Source
AI summary
Embodiments of broadcasting receiver and methods for the same can operate two or more tuners or simultaneously display broadcasting signals of two or more channels. Embodiments of the invention can reduce system interference. A broadcasting receiver can include a plurality of tuners, and a controller for operating a tuner of a broadcasting signal not being displayed using an oscillation frequency that has reduced or avoids interference with another tuner of a currently selected and displayed broadcasting signal. For example, an interference controller can read stored PLL data with reference to a channel frequency of a currently selected and displayed broadcasting signal and write the read PLL data in other tuner(s) when only a broadcasting signal received by one of the tuners is currently selected and displayed.