Display Driver Voltage Boosting Clock Control

Solution Overview

Problem

Existing drivers for display panels face inaccuracies in sampling and holding driving voltages due to noise from voltage boosting circuits, leading to errors in pixel write voltages and decreased display quality.

Innovation Solution

A driver with a voltage boosting circuit that includes a voltage boosting unit and a control circuit to stop the voltage boosting clock during switching from sampling to holding periods, preventing noise-induced errors by maintaining a stable boosted voltage and resuming the voltage boosting operation asynchronously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the voltage boosting operation is continuously performed to maintain a constant boosted voltage, then the boosted voltage stability is improved, but noise is generated during resumption which propagates to other circuits and causes voltage sampling errors

Engineering Contradiction:

Improveboosted voltage stabilityVSAvoidnoise propagation to driving circuit

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The voltage boosting clock is stopped in advance during the sampling period to prevent noise from affecting the voltage sampling process. By proactively disabling the voltage boosting operation before sampling occurs, the patent eliminates the harmful noise interference that would otherwise propagate to the driving circuit during critical sampling moments.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The voltage boosting operation is performed periodically by alternating between active and inactive states. The voltage boosting clock is enabled during non-sampling periods to maintain boosted voltage stability, and disabled during sampling periods to prevent noise propagation. This periodic switching resolves the contradiction by timing the boosting operation to avoid interfering with voltage sampling.

Inventive Principle:

Principle #19Periodic action

2Measurement precision

If the voltage boosting clock is stopped during the sampling period to prevent noise, then voltage sampling accuracy is improved, but the boosted voltage may become unstable

Engineering Contradiction:

Improvevoltage sampling accuracyVSAvoidboosted voltage stability

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The voltage boosting clock operates periodically, being enabled during non-sampling periods to maintain boosted voltage stability and disabled during sampling periods to ensure voltage sampling accuracy. This periodic switching strategy allows the system to achieve both goals by timing the boosting operation appropriately.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The voltage boosting control circuit automatically adjusts its operation based on the sampling period timing. By detecting when the driving circuit is in sampling mode, the control circuit self-regulates the voltage boosting clock to be inactive during sampling and active during non-sampling periods, maintaining both accuracy and stability without external intervention.

Inventive Principle:

Principle #25Self-service

3Stability of the object's composition

If the voltage boosting operation is resumed frequently to maintain constant boosted voltage, then the boosted voltage stability is improved, but noise is generated more frequently which affects driving voltage sampling

Engineering Contradiction:

Improveboosted voltage stabilityVSAvoiddriving voltage sampling precision

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The voltage boosting clock is stopped in advance during the sampling period to prevent noise from affecting the voltage sampling process. By proactively disabling the voltage boosting operation before sampling occurs, the patent eliminates the harmful noise interference that would otherwise propagate to the driving circuit during critical sampling moments.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The voltage boosting operation is performed periodically by alternating between active and inactive states. The voltage boosting clock is enabled during non-sampling periods to maintain boosted voltage stability, and disabled during sampling periods to prevent noise propagation. This periodic switching resolves the contradiction by timing the boosting operation to avoid interfering with voltage sampling.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS10037731B2Driver, electro-optical apparatus, and electronic device

Publication Date: 2018.07.31 SEIKO EPSON CORP

AI summary

A driver includes a power supply circuit including a voltage boosting circuit that generates a boosted voltage by performing a voltage boosting operation, and a driving circuit that receives a power supply from the power supply circuit, and samples a driving voltage to drive a display panel. The voltage boosting circuit has a voltage boosting unit having a voltage boosting transistor, and a voltage boosting control circuit that outputs a voltage boosting clock signal to the voltage boosting unit. The voltage boosting control circuit stops the voltage boosting clock signal in a first period that includes a timing of an end of a sampling period of the driving circuit.