Luminance Correction for Display Camera Region Flickering
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Solution Overview
Problem
Light emitting display apparatuses driven at low frequencies often experience luminance differences between refresh and anode reset periods, leading to image flickering and reduced image quality, especially around camera areas where transistor degradation occurs.
Innovation Solution
A luminance difference correction method that analyzes images input to a camera at the lower end of the display panel, varying gamma voltage and driving voltages to the pixels to minimize luminance discrepancies and compensate for reduced luminance in camera regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a light emitting display apparatus is driven at low frequency with refresh period and anode reset period, then power consumption is reduced, but luminance difference occurs between refresh period and anode reset period causing image flickering
Solution Approach 1:
The patent applies preliminary action by measuring the luminance of the camera area during the refresh period before the anode reset period begins, and using this measurement to adjust the gamma voltage and driving voltages in advance for the upcoming anode reset period. This proactive adjustment prevents luminance instability rather than reacting to it after occurrence.
Solution Approach 2:
The patent implements feedback by using the camera to continuously measure the luminance of the camera area during both refresh and anode reset periods, comparing the measured luminance with reference values, and adjusting gamma voltages and driving voltages based on the comparison results. This closed-loop control maintains luminance stability while operating at low frequencies.
2Reliability
If the display is continuously used, then the camera area transistors degrade leading to reduced luminance in camera region, but increasing driving voltage to compensate increases power consumption
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gamma voltage and driving voltages based on the measured luminance of the camera area. When transistor degradation is detected through luminance measurement, the system modifies voltage parameters to compensate for the degradation, thereby maintaining display quality without excessive power consumption increases.
Solution Approach 2:
The patent implements local quality by applying different voltage adjustments specifically to the camera area based on its measured luminance characteristics, rather than uniformly adjusting the entire display. The gamma voltage and driving voltages are modified locally for the camera region to compensate for transistor degradation while minimizing overall power consumption impact.
3Stability of the object's composition
If gamma voltage and driving voltages are adjusted to compensate for luminance difference, then image flickering is reduced, but device complexity increases
Solution Approach 1:
The patent applies universality by using the camera, which is already present in the display apparatus for other purposes, to perform luminance measurement functions. This multi-functional use of the camera avoids adding dedicated measurement hardware, thereby limiting the increase in device complexity while achieving luminance stability.
Solution Approach 2:
The patent implements self-service by enabling the display apparatus to automatically measure its own luminance using the integrated camera and automatically adjust its own gamma voltages and driving voltages based on the measurements. This self-diagnosis and self-correction mechanism reduces the need for external calibration equipment and complex control systems.
Data Source
AI summary
A luminance difference correction method and a light emitting display apparatus using the same is discussed. The luminance difference correction method can include receiving by an camera an image, which is output from a camera region of a light emitting display panel and is reflected by at least one of a reflector or a cover glass associated with the apparatus. The method can further include analyzing by a controller the image received by the camera, and varying a level of at least one of (i) a gamma voltage used to generate a data voltage to be output to data lines included in the light emitting display panel, and (ii) one or more of driving voltages supplied to pixels included in the light emitting display panel.