Rod Lens Array Research Articles

World's First Success of Developing the Plastic Rod-lens Array

World's First Success of Developing the Plastic Rod-lens Array

Holographic shift multiplexing by using rod lens array referencing

We demonstrate both theoretically and experimentally a shift multiplexing method for holographic data storage by using a rod lens and rod lens array (RLA). RLA referencing provides a simple and effective way to increasing the holographic storage density. The sidelobe intensity is reduced to 0.3% and multiple holograms are proven to be stored with a spatial separation of 1.2 μm without crosstalk.

Elimination of the Circumferential Part of a Plastic Rod Lens for Improving its Optical Resolution

A commercially available plastic rod-lens array has an optical resolution applicable to 200 dots per inch (dpi) devices. Recently, we developed a technique for dyeing the circumferential part of the rod lens, which achieved a sufficient resolution for 300 dpi devices but not for 400 dpi devices. In this study, we have developed a technique of eliminating the circumferential part of the rod lens for improving its optical resolution. Both higher resolution applicable to 400 dpi devices and high durability have been realized by this surface eliminating technique.

Improvement of chromatic aberration of a plastic rod lens array. 1. Combination-color lens arrays consisting of several kinds of rod lenses with different gradient constants and different color filter functions.

We propose a new type of rod lens array with improved chromatic aberration. The new rod lens array consists of several kinds of rod lenses with different gradient constants and different color filter functions. The gradient constant of each lens was prepared such that the total conjugate length was identical to the specific wavelength of the lens with a constant lens length. We call our new type of rod lens array a combination-color lens array. The characteristics of this color-type lens array are as follows: high angular aperture, short focal length, and ease of production with established procedures. The optical resolution of the rod lens array is 300 dpi in a wide wavelength range that is high enough to be applied to color scanners.

Dyeing of the Circumferential Part of a Plastic Rod Lens for Improving its Optical Resolution

A plastic rod-lens array that we developed industrially with a continuous spinning technique has an optical resolution of 200 dpi (4 lp/mm), and it has been used for facsimile machines and other applications. However, this resolution is still insufficient for its application in image scanners, copy machines, and light emitting diode (LED) printers. During the study for improving the optical resolution of the plastic rod-lens array, we have confirmed that this resolution is determined by the deviation of refractive index distribution from the ideal one at the outer circumferential part. Therefore, we have developed a technique for dyeing the outer circumferential part of the rod lens in order to achieve the higher optical resolution power of 300 dpi (6 lp/mm).

Mutual diffusion process for continuous fabrication of graded-index plastic rod lenses.

We propose a new process for fabrication of plastic rod lenses based on the traditional method of fiber extrusion. The process consists of the following steps: multilayer conjugate extrusion, monomer diffusion between adjacent layers, and photopolymerization of an uncured strand fiber. We call this process a mutual diffusion process for continuous plastic rod lens fabrication. Characteristics of this process are as follows: fast production speed (approximately 100 cm/min), precision control of refractive-index distribution, high angular aperture, and long-term reliability. The optical resolution of the rod-lens array is 300 dpi, which is high enough for application to G3 facsimiles with transmission time of less than 1 min and monochromatic scanners.

Ion beam assisted deposition of a thin film coating on a gradient-index lens array

A new coating method which employs ion bombardment has been developed for a gradient-index (GRIN) rod lens array using silicone rubber and fiber reinforced plastic plates in its construction. The thin film coatings deposited using this method passed the durability tests on the basis of MIL-M-13508C. The adhesion of the thin film coating was strong and durable enough to allow for use on GRIN rod lens arrays in photocopiers. The effect of ion bombardment has been investigated with thin film analysis data by Fourier transform infrared microspectroscopy and secondary ion mass spectrometry.