Compensation of image noise induced by difference in optical characteristics of array-LED chips of LED print head  

作　　者：KIM Wan-Chin PARK Yong-Shik KIM Sung-Dae LIM Jiseok 

机构地区：[1]Department of Automotive Engineering, Honam University, Gwansan-gu, Gwangju 62399, Korea [2]Mangoslab Co., Ltd., Startupeampus, 20, Pangyo-ro 289beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 13488, Korea [3]S-Printing Solution Co., Ltd. (Samsung Electronics Ltd,), Suwon, Gyeonggi-do 443-742, Korea [4]School of Mechanical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea

出　　处：《Science China(Technological Sciences)》2017年第12期1819-1830,共12页中国科学（技术科学英文版）

基　　金：supported by the National Research Foundation of Korea Grant funded by the Korean Government(Grant No.2015R1C1A1A01053888);the Yeungnam University Research Grant(Grant No.216A580022)

摘　　要：There are various applied electro-optical devices, which utilize light emitting didoe(LED) chip array for applications to displays and opto-electronic sensors. In those devices, it is the one of the critical technical issues to minimize uncertain fluctuations including optical power and optical density. Due to variation in operating environment of a device, those are not corrected precisely by controlling parameters based on simple relation between parameters and resultant abovementioned outputs.Therefore, there is essential need to correct outputs in real-time based on correction function generated from the consideration on various operation condition. In this article, we introduce an output correction method through reporting real-time image noise reduction in the application to electro-photography with LED print head. In the technology of LED print head, as differences in optical characteristics between each LED cause vertical image noise, it should be corrected in order to obtain images that are comparable or better in quality compared to those produced by the conventional laser scanning method. Even though it seems that the method used to obtain uniform light power from each LED can solve this problem, it does not work well for high-resolution printing. Therefore, a scan method involving correction by a printed and scanned pattern is introduced through this work. The scan method is composed of correction patterns to minimize printing noise by its shape, the correction algorithm to calculate the optimized value and the printing algorithm to control gray levels in real-time precisely. We believe that the developed correction method upgrades the printing quality of the LPH printer better than commercial printers. The developed correction method can also be applied to various application areas that use an array-type light source such as display systems and lighting systems.There are various applied electro-optical devices, which utilize light emitting didoe（LED） chip array for applications to displays and opto-electronic sensors. In those devices, it is the one of the critical technical issues to minimize uncertain fluctuations including optical power and optical density. Due to variation in operating environment of a device, those are not corrected precisely by controlling parameters based on simple relation between parameters and resultant abovementioned outputs.Therefore, there is essential need to correct outputs in real-time based on correction function generated from the consideration on various operation condition. In this article, we introduce an output correction method through reporting real-time image noise reduction in the application to electro-photography with LED print head. In the technology of LED print head, as differences in optical characteristics between each LED cause vertical image noise, it should be corrected in order to obtain images that are comparable or better in quality compared to those produced by the conventional laser scanning method. Even though it seems that the method used to obtain uniform light power from each LED can solve this problem, it does not work well for high-resolution printing. Therefore, a scan method involving correction by a printed and scanned pattern is introduced through this work. The scan method is composed of correction patterns to minimize printing noise by its shape, the correction algorithm to calculate the optimized value and the printing algorithm to control gray levels in real-time precisely. We believe that the developed correction method upgrades the printing quality of the LPH printer better than commercial printers. The developed correction method can also be applied to various application areas that use an array-type light source such as display systems and lighting systems.

关 键 词：real-time image correction LED print head(LPH) vertical image noise electro-photography temporal correction spatial correction 

分 类 号：TN312.8[电子电信—物理电子学]