LCD Controller Oscillator Prebias Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing LCD controller designs require a large number of I/O pins for capacitive switch sensing circuitries and LCD driver controllers, leading to increased chip size and complexity, and there is a need for power conservation in maintaining continuous displays without changing for long periods.
Innovation Solution
An LCD controller with a charge pump circuit for generating charge voltage, an oscillator with high and low power modes, and bias circuitry for applying bias voltages, along with an LCD driver voltage circuit to drive LCD segments efficiently, allowing for reduced power consumption and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dedicated LCD driver controllers and capacitive sensing circuitry with large numbers of I/O pins are used, then the LCD display can be controlled and capacitive switches can be detected, but the chip size and device complexity increase
Solution Approach 1:
The patent combines the LCD driver controller and capacitive sensing circuitry into a single integrated device. The controller includes both LCD driver circuitry for controlling display segments and capacitive sensing circuitry for detecting touch inputs, eliminating the need for separate dedicated circuits and reducing overall chip size.
Solution Approach 2:
The integrated controller performs multiple functions within a single device: it drives LCD segments, detects capacitive switch activations, and manages power consumption. This multi-functional approach allows one chip to replace what would traditionally require multiple separate components.
2Duration of action of stationary object
If the LCD controller maintains continuous display functionality, then the display remains visible, but power consumption increases
Solution Approach 1:
The patent implements periodic refreshing of the LCD display rather than continuous updates. The controller refreshes the display at intervals sufficient to maintain visual continuity while allowing power consumption to be reduced during non-refresh periods. This is achieved through the oscillating control signal that periodically updates segment voltages.
Solution Approach 2:
The controller dynamically adjusts operating parameters including refresh rate and power supply voltage based on display requirements. When continuous display is needed, higher refresh rates are used; when power conservation is prioritized, the refresh rate is reduced while maintaining acceptable visual quality through persistence of image effects.
Data Source
AI summary
An LCD controller includes a charge pump circuit for generating a charge voltage responsive to an external voltage and a clock signal. An oscillator generates the clock signal responsive to at least one bias voltage. The oscillator has a high power mode of operation and a low power mode of operation. Bias circuitry for applies the at least one bias voltage to the oscillator. The at least one bias voltage is applied to the oscillator from an external source in the high power mode of operation and the at least one bias voltage is applied to the oscillator from a source within the oscillator in the low power mode of operation. An LCD driver voltage circuit generates a plurality of LCD driver voltages for driving segments of an LCD display responsive to the charge voltage.