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Automated Light Source Monitor

IP.com Disclosure Number: IPCOM000051579D
Original Publication Date: 1981-Feb-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Balder, W: AUTHOR [+3]

Abstract

A light source monitor for a projection printing tool, having an adjus scanning slit consists of a sense head 1, a trimmer box 2, and a controller 3. The sense head 1 has thirteen photovoltaic sensors 4 (for a 57 mm array) which are mounted in a wafer chuck 5 so that sense head 1 can be loaded into the tool using the existing chuck-handling mechanisms. Sensors 4 are arranged to correspond with the arc of the slit. Eleven of the sensors 4 are used to determine the intensity and energy at each slit correction point, while the remaining two sensors are used to measure the slit speed. Trimmer box 2 is used to calibrate the output of each sensor 4 to a known absolute standard. Controller 3 consists of an operator keyboard and display, a 16-channel A/D converter and a microprocessor with associated memory and I/O.

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Automated Light Source Monitor

A light source monitor for a projection printing tool, having an adjus scanning slit consists of a sense head 1, a trimmer box 2, and a controller 3. The sense head 1 has thirteen photovoltaic sensors 4 (for a 57 mm array) which are mounted in a wafer chuck 5 so that sense head 1 can be loaded into the tool using the existing chuck-handling mechanisms. Sensors 4 are arranged to correspond with the arc of the slit. Eleven of the sensors 4 are used to determine the intensity and energy at each slit correction point, while the remaining two sensors are used to measure the slit speed. Trimmer box 2 is used to calibrate the output of each sensor 4 to a known absolute standard. Controller 3 consists of an operator keyboard and display, a 16-channel A/D converter and a microprocessor with associated memory and I/O. The processor calculates the light energy by summing the measured intensity at each sensor at a high rate of speed. The energy is used to calculate the effective lamp/slit uniformity using the formula: (Max energy - min energy) X 100% over Average Energy.

If the uniformity does not meet the specification, it can be corrected by adjusting the slit width. The amount of correction at each point on the adjustable slit is calculated and displayed by the apparatus. The peak intensity, average energy and energy uniformity are also displayed. In addition, the correction to the scan speed is calculated by using the average energy measure...