A study of extended optimization of U-type rod for LED projectors

Hung, Chuan-Cheng; Sun, Jung-Hung; Tzeng, Yiharn; Macdonald, John; Lai, Wei–Chih; Li, Si-Xiang; Fang, Yi-Chin; Sun, Hung-Chi; Chen, Yiliang

doi:10.1016/j.ijleo.2010.03.002

Cited by 6 publications

(6 citation statements)

References 5 publications

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“…The relationships between the focal length, voltage, and pore size are as shown in Table 2. The liquid crystal lens data referenced the research results obtained by Yingling Chenrom, Chungshan University on modulating liquid crystal lens using voltage [2]. The initial application of dimming backlight technology was used in liquid crystal displays.…”

Section: The Design Of the Dimming System With Liquid Crystal Lens Arraymentioning

confidence: 85%

“…Recently, there has been a trend to integrate them into many systems, and it is likely that in the future, everyone can have a portable projector to use for presentations, education, recreation, and other purposes. Sometimes the demands made of a projector require some of its characteristics to be significantly enhanced [1][2][3][4]. For example, if the light is switched on while the projector is in use, it should substantially increase the brightness of the projector.…”

Section: Introductionmentioning

confidence: 99%

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Application of Dimming Compensation Technology Via Liquid Crystal Lens for Non-Imaging Projection Laser Systems

2019

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The main purpose of this paper is to explore a newly developed optical design, then to further improve the overhead lighting contrast in the laser projector module. In terms of the structural design of the projector, a liquid crystal lens array was used as the local dimming system for the light source, in order to achieve the objective, which was to significantly improve the contrast facility of the projection system. Second, in terms of the design of the light source, the output method for the light source was a laser light source employing arrays of micro-scanning. The main purpose was to compensate for the dim spots in the hole between the lenses in each unit of the liquid crystal when the liquid crystal lens array was locally dimmed, and thus significantly improving the contrast facility of the projection system. In terms of the software simulation, a liquid crystal lens array was used to simulate a pore size of 2.0 mm and focal lengths of 9 cm and 23 cm. The end effect gave good control and adjustment of the bright and dark areas during local dimming of the projector’s imaging chip components. For a single laser source, the maximum contrast for local dimming was about 128:1, 438:1, and 244:1, for the Red (R), Green (G), and Blue (B) optical paths, respectively. The light efficiency scores were approximately 20.91%, 20.05%, and 24.45%, for the R, G, and B optical paths, respectively. After compensation using a micro-scanning light source, the defect of having dim spots between the pores was remedied, and the light adjustment area became more uniform while the contrasts became smaller. The maximum contrasts were approximately 52:1, 122:1, and 110:1, for the R, G, and B optical paths, respectively. For the projector, when the liquid crystal lenses were not transmissive, the maximum uniformity scores were 82.25%, 87.15%, and 88.43%, for the R, G, and B optical paths, respectively.

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Section: The Design Of the Dimming System With Liquid Crystal Lens Arraymentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Application of Dimming Compensation Technology Via Liquid Crystal Lens for Non-Imaging Projection Laser Systems

2019

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“…As for the relay illumination system, it notably influences the width and thickness of the engine [11,[13][14][15][16][17][19][20][21][22][23][24][25]. Also, it mainly determines the efficiency and the uniformity of the screen.…”

Section: Introductionmentioning

confidence: 99%

Optical Engine Design for a Compact, High-Luminance DLP Projector Using Four-Channel LEDs and a Total Internal Reflection Prism

2023

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How to obtain higher brightness with a small volume projection engine for 4K resolution digital light processing (DLP) is of great significance. In this paper, we first use the fourth channel serving as a blue pump leading to a 52% gain of green brightness. Secondly, a new inline total internal reflection prism glued with a spherical mirror is constructed to notably reduce the length of the relay illumination system by more than 10 mm, resulting in a more compact optical engine with a volume of 210 × 140 × 36 mm3. Thirdly, a projection lens is optimized with a modulation transfer function higher than 0.6 at 93 lines for a distance of 2125 mm with distortion lower than 1%. As a result, the efficiencies of RGB lights are higher than 60%, and the luminance and uniformity on the screen reach 1412 lm and 94.5% measured by the prototype. Our proposed projection system is significantly helpful for designing a compact and high-luminance 4K DLP projection.

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“…Using the true digital pixels, the screen shows a rapid response, and the relevant technology is also used in projectors. Therefore, the existing projection display technology has included the use of LED on DMD projectors [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Compact LED projector design with high uniformity and efficiency

et al. 2014

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The aim of this study is to design a compact LED projector that is divided into two systems: an illumination system and an imaging optical system. The illumination system consists of an RGB LED light source with a collimator lens group and a mirror with a color filter and a lens array integrator instead of an integrated rod so as to improve the uniformity of the light intensity. By using a new total internal reflection prism and projection lens, the whole optical engine is smaller in size and has a higher contrast ratio for image quality. The imaging optical system consists of a total of eight lenses (six spherical lenses and two aspherical lenses), for a total length of 52 mm; a tolerance analysis is conducted. Optical simulation software is used for the system analysis in order to determine the efficiency and uniformity of the light intensity. In this design, the uniformity of the screen reaches more than 82%, and the efficiency increases by more than 44%.

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A study of extended optimization of U-type rod for LED projectors

Cited by 6 publications

References 5 publications

Application of Dimming Compensation Technology Via Liquid Crystal Lens for Non-Imaging Projection Laser Systems

Application of Dimming Compensation Technology Via Liquid Crystal Lens for Non-Imaging Projection Laser Systems

Optical Engine Design for a Compact, High-Luminance DLP Projector Using Four-Channel LEDs and a Total Internal Reflection Prism

Compact LED projector design with high uniformity and efficiency

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