Display Light Measurement Calibration with Delayed Dark Sampling
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Solution Overview
Problem
Existing display light measuring apparatuses face accuracy issues due to residual electric charges in integration capacitors during zero calibration, particularly in low luminance regions, as they fail to adequately address errors caused by incomplete reset operations.
Innovation Solution
Incorporating a light shielding member to block incident light during zero calibration, a controller to set a delay time for acquiring dark output values, and an integration circuit with adjustable integration capacitors to minimize residual charges, ensuring accurate calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If zero calibration is performed immediately after light measurement without delay, then measurement speed is improved, but residual electric charges in the integration capacitor cause calibration errors and reduced accuracy
Solution Approach 1:
The patent applies preliminary action by introducing a delay period before acquiring the dark output value for zero calibration. This delay allows residual electric charges in the integration capacitor to dissipate naturally before measurement, ensuring that the calibration is performed on a fully reset baseline. The controller is configured to automatically implement this delay, preventing calibration errors without requiring manual intervention or complex reset circuitry.
2Measurement precision
If the integration capacitor is used to accumulate electric charge for wide dynamic range measurement, then low luminance detection capability is improved, but residual charges from previous measurements cause errors in subsequent zero calibration
Solution Approach 1:
The patent uses time as an intermediary element to resolve the conflict between charge accumulation and error prevention. By introducing a controlled delay period between measurement and calibration operations, the system allows residual charges to naturally dissipate through leakage paths without requiring additional reset circuitry or active discharge mechanisms. This temporal separation ensures that the integration capacitor is fully reset before zero calibration begins.
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
The solution effectively suppresses errors in zero calibration by eliminating residual charges, enhancing accuracy across various luminance ranges, including low luminance regions.
Implementation Method 1
an optical sensor; an integration circuit that has an integration capacitor and accumulates electric charge output from the optical sensor
Data Source
AI summary
A display light measuring apparatus includes: an optical sensor, an integration circuit that has an integration capacitor and accumulates electric charge output from the optical sensor; a light shielding member that shields incident light on the optical sensor; a calibrator that acquires a dark output value which is an output value of a quantity of incident light on the optical sensor in a state where the incident light on the optical sensor is shielded by the light shielding member, the calibrator performing zero calibration on the basis of the acquired dark output value; and a controller that sets a delay time for delaying the acquisition of the dark output value.