21 February 2007 Diffraction grating lens array
Author Affiliations +
We have proposed a new type of camera module with a thin structure and distance-detection capability. This camera module has a four-lens-array with diffraction gratings (one for blue, one for red, and two for green). The diffraction gratings on the mold are formed mechanically, and the plastic lens array is fabricated by injection molding. The two green images are compared to detect parallax, and parallax-corrected blue, red and green images are then composed to generate a color image. We have developed new design software and molding technologies for the grating lenses. The depth and period of blazed gratings and the shapes of aspheric lenses are optimized; and blue, red and two green aspheric lenses with gratings are molded as a single four-lens-array. The diffraction gratings on both surfaces of each lens act to improve field curvature and realize wide-angle imaging. However, blazed gratings sometimes cause unnecessary diffraction lights that impede the formation ofhigh-resolution images. We have developed a new method to measure necessary first-order diffraction lights and unnecessary diffraction lights separately. Use of this method allows the relationship between molding conditions and necessary/unnecessary diffraction lights to be shown. Unnecessary diffraction lights can be diminished by employing the optimal molding processes, allowing our grating lenses to be used for image capture.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Tsuguhiro Korenaga, Tsuguhiro Korenaga, Takamasa Ando, Takamasa Ando, Seiji Moriguchi, Seiji Moriguchi, Fuminori Takami, Fuminori Takami, Yoshifumi Takasu, Yoshifumi Takasu, Seiji Nishiwaki, Seiji Nishiwaki, Masa-aki Suzuki, Masa-aki Suzuki, Michiyoshi Nagashima, Michiyoshi Nagashima, } "Diffraction grating lens array", Proc. SPIE 6501, Sensors, Cameras, and Systems for Scientific/Industrial Applications VIII, 65010T (21 February 2007); doi: 10.1117/12.702738; https://doi.org/10.1117/12.702738


A Simple Approach To Common Lens Design
Proceedings of SPIE (June 10 1987)
The Principles Of Aberration-Corrected Optical Systems
Proceedings of SPIE (February 14 1986)
Design challenges for the 1990s
Proceedings of SPIE (January 01 1991)
How to design and tolerance with GRADIUM glass
Proceedings of SPIE (September 21 1998)
Application of diffractive optics to laser scan lenses
Proceedings of SPIE (May 12 1995)
Optical design of reflective wide-field cameras
Proceedings of SPIE (August 29 2008)
MTF optimization in intraocular lens (IOL) design
Proceedings of SPIE (May 26 1994)

Back to Top