Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

THERMOPLASTIC HOLOGRAPIC RECORDING IN THE NEAR-INFRARED

IP.com Disclosure Number: IPCOM000026473D
Original Publication Date: 1992-Apr-30
Included in the Prior Art Database: 2004-Apr-05
Document File: 4 page(s) / 154K

Publishing Venue

Xerox Disclosure Journal

Abstract

A thermoplastic coated recording device that is sensitive to near-infrared wave lengths may be used as a high sensitivity recording medium for holograms when an AlGaAs diode laser or a visible laser is used as a light source.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

THERMOPLASTIC HOLOGRAPIC Proposed Classification RECORDING IN THE NEAR-
INFRARED
Int. C1. G03g 15/00 John R. Andrews
Clifford H. Griffiths

U.S. C1.355/200

otoconductor

ransparent Ground

XEROX DISCLOSURE JOURNAL - Vol. 17, No. 2 MarcNAprill992 85

[This page contains 1 picture or other non-text object]

Page 2 of 4

THERMOPLASTIC HOLOGRAPIC RECORDING IN THE NEAR- INFRARE D( Cont 'd)

A thermoplastic coated recording device that is sensitive to near-infrared wave lengths may be used as a high sensitivity recording medium for holograms when an AlGaAs diode laser or a visible laser is used as a light source.

A holographic recording process using the thermoplastic coated recording device begins with corona charging of an outer thermoplastic surface layer in the dark followed by optical exposure with a high spatial frequency (10-4000 lp/mm) intensity variation while attached to ground. In areas were light intensity is high within the photoconductive layer, charge flows from a transparent ground plane to an interior surface of the thermoplastic layer to partially neutralize the electrostatic charge on the exterior surface of the thermoplastic layer. Subsequent corona charging in the dark allows a greater charge to be deposited in the areas that were illuminated in the exposure step. Heating of the thermoplastic layer to its melting point allows the exterior surface to deform, the exterior surface thinning where the most charge is deposited, that is the illuminated areas, and thickening where charge densities are the lowest. A resultant exterior surface relief pattern forms a phase hologram when used as the recording medium in a holographic exposure setup.

The holographic recording device is comprised of: a supporting substrate that has a conducting ground plane; a transparent ground plane; a photoconductive layer, that is about 10 microns thick; and a thin thermoplastic exterior layer that is about 0.2 microns thick as shown in the figure. The photoconductive base uses a near-infrared photoconductor composition as used in xerographic photoreceptors.

Photoreceptors containing the photoconductive pigment vanadyl phthalocyanine (VOPc) are a particularly favored embodiment of the photoconductive layer in holographic recording devices. It has been found in xerographic applications that these photoreceptor provide the following properties: good cyclic stability; long life; a nearly flat response and high sensitivity in the 750 - 850 nm range where AlGaAs diode lasers operate; and high s...