Browse Prior Art Database

Multiple Band Uniformity And Exposure Control Detector for a Projection Printer

IP.com Disclosure Number: IPCOM000061985D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Lagoe, DC: AUTHOR [+2]

Abstract

Three broad band intensity detectors, each having associated narrow bandpass filters, are assembled in a housing previously containing a single detector. This approach eliminates the need to insert a filter in the exposure beam, thus increasing available actinic intensity during photoresist exposure.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 87% of the total text.

Page 1 of 1

Multiple Band Uniformity And Exposure Control Detector for a Projection Printer

Three broad band intensity detectors, each having associated narrow bandpass filters, are assembled in a housing previously containing a single detector. This approach eliminates the need to insert a filter in the exposure beam, thus increasing available actinic intensity during photoresist exposure.

The practice of placing filters in the exposure beam of a projection printer to match spectral sensitivity of a detector to the actinic spectrum of a photoresist currently in use, leads to actinic intensity attenuation. By associating appropriate narrow bandpass filters with each of several detectors, the actinic spectral region of a photoresist currently in use may be assessed in the exposure beam by electrically selecting output from an appropriate detector. Thus, intensity used to expose the photoresist is no longer attenuated by a filter.

The figure shows a housing 2 of size and shape which previously contained only a single detecting diode. In this design, housing 2 has three apertures 4 exposing three detecting diodes contained in housing 2 with individual filters mounted in front of each diode. Electrical connections to the diodes are brought out of housing 2 via cable 6 which is run to a selecting switch on the control panel of the projection printer. Thus, an operator may select a detector with sensitivity in an appropriate spectral region to match the actinic spectrum of photore...