Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Yang, Can; Su, Lijuan; Huang, Chien-Hung; Huang, Han‐Xiong; Castro, José M.; Yi, Allen Y.

doi:10.1002/adv.20211

Cited by 40 publications

(26 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is an effective packing with high packing pressure and long packing time. Thus, compared with previous studies [5,7], the distribution variation is relatively small with a maximum deviation of 6 × 10 −4 . In addition to the small deviation, because higher packing pressure occurs closer to the injection gate, the general trend of the distribution decreases along the flow direction.…”

Section: Resultscontrasting

confidence: 66%

“…The geometric deformation primarily has an impact on optical refraction, so the nodes' positions on the top and bottom surface meshes were extracted for numerical analysis of its optical aberrations in the next section. Furthermore, uneven cooling as well as the polymer's rheological properties could result in an unevenly distributed density that consequently causes variation in refractive index [7]. Therefore, refractive index information at each node was also collected for optical aberration analysis.…”

Section: B Injection Molding Simulationmentioning

confidence: 99%

“…Park and Joo applied FEM analysis results of an injection molded lens to a ray-tracing simulation [5] and concluded that inhomogeneous distribution of the refractive index could occur if molding conditions were not carefully controlled. Besides the simulations for refractive index distribution, Huang [6] and Yang et al [7] discussed the refractive index variation of injection molded precision optical lenses using two different experimental setups.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simulation and measurement of optical aberrations of injection molded progressive addition lenses

Raasch

2013

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

Injection molding is an important mass-production tool in the optical industry. In this research our aim is to develop a process of combining ultraprecision diamond turning and injection molding to create a unique low-cost manufacturing process for progressive addition lenses (PALs). In industry, it is a well-known fact that refractive index variation and geometric deformation of injection molded lenses due to the rheological properties of polymers will distort their optical performance. To address this problem, we developed a method for determining the optical aberrations of the injection molded PALs. This method involves reconstructing the wavefront pattern in the presence of uneven refractive index distribution and surface warpage using a finite element method. In addition to numerical modeling, a measurement system based on a Shack-Hartmann wavefront sensor was used to verify the modeling results. The measured spherocylindrical powers and aberrations of the PALs were in good agreement with the model. Consequently, the optical aberrations of injection molded PALs were successfully predicted by finite element modeling. In summary, it was demonstrated in this study that numerically based optimization for PAL manufacturing is feasible.

show abstract

Section: Resultscontrasting

confidence: 66%

Section: B Injection Molding Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simulation and measurement of optical aberrations of injection molded progressive addition lenses

Raasch

2013

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This measurement was performed in a field of 126 μ m × 96 μ m, with a best-fit spherical surface removed from the measurement. To form an optical surface, the roughness should be 10 to 20 times smaller than the light wavelengths [ 26 ]. For this measurement, the arithmetical mean roughness ( R a ) is 4.77 nm, the root mean square roughness ( R q ) is 6.31 nm, and the total height of the roughness ( R t ) is 234.89 nm.…”

Section: Micro Surface Roughnessmentioning

confidence: 99%

Manufacturing of a precision 3D microlens array on a steep curved substrate by injection molding process

Zhang

Scheiding²,

et al. 2013

Advanced Optical Technologies

Self Cite

View full text Add to dashboard Cite

In this study, a high volume low cost manufacturing method for microoptical microlens arrays on steep curved substrates using a microinjection molding technique was investigated. The design of the individual lenslets was performed using ZEMAX. This 3D microlens array in this study contains 1219 microlenses that are evenly distributed on its concave surface with a high fill factor. The overall field of view of this microlens array on curved substrates is more than 104°. To complete the manufacturing process, first the mold inserts were machined using a voice coil based fast tool servo technique, then the 3D microlens arrays were injection molded. The injection molding process parameters were evaluated using both experiments and numerical simulation for best molding results. In addition, both geometrical errors and optical performance tests showed that the molded polymer microlens arrays can be used in wide angle imaging applications. This study demonstrated that this combined process is capable of fabricating high precision microlens arrays at steep curved substrates at low cost. The microlens arrays created in this study have broad applications in optical, medical and biomedical domains. The success of this study provided a feasible solution for mass production of 3D microlens arrays on arbitrary substrates

show abstract

“…Shibuya used COC and COP as materials and demonstrated that optical retardation of the sensor lens became high if the birefringence of materials was high, and reported that environmental stress degraded the resolution [6]. Yang et al used PMMA as a material and reported that the filling pressure at the molding process of the optic plastic lens influences the refractive index profile of the molded parts [7].…”

Section: Introductionmentioning

confidence: 99%

Optical characteristics of injection-molded fluorene polymers

Kato¹,

Ito²

2013

Journal of Polymer Engineering

View full text Add to dashboard Cite

Digital cameras are small, but they must be able to take images with numerous pixels. To use few lenses in devices, aspheric lenses have been used. Fluorenebased polymers (FBPs) have a high refractive index and low birefringence. Because optical lenses must be manufactured as designed with low optical retardation, FBP optical lenses are widely used. This study assessed optical and flow characteristics of polycarbonate (PC) and two kinds of FBP. Molded specimen characteristics of PC and two FBPs revealed these properties of the FBPs. The results show that the unique structure of FBPs eliminated birefringence, because of the cardo structure part, including the fluorene ring. Differences in optical properties are attributable to structural differences of the part which is polymerized with the fluorene structure (the X part). The temperature dependence of FBPs in the flow characteristics and optical properties was smaller than that of PC; the slight temperature dependence is particularly obvious above the glass transition temperature (T g ). The benzene ring content of FBP affects the resin optical and physical properties. The influence of the difference between the fluorene polyester structure and the PC structure was greater than that of the benzene ring content in the X part, in the molecular structure of FBP.

show abstract

Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens

Cited by 40 publications

References 21 publications

Simulation and measurement of optical aberrations of injection molded progressive addition lenses

Simulation and measurement of optical aberrations of injection molded progressive addition lenses

Manufacturing of a precision 3D microlens array on a steep curved substrate by injection molding process

Optical characteristics of injection-molded fluorene polymers

Contact Info

Product

Resources

About