Browse Prior Art Database

Photographic Image Definition Tolerance Control Chart

IP.com Disclosure Number: IPCOM000091236D
Original Publication Date: 1967-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Ladd, RS: AUTHOR

Abstract

Tolerance control chart 10, useful in photographic processing, comprises a plurality of individual halftone checkerboard patterns 1...9 each of the same over-all area. Each pattern consists of a like number of opaque and transparent squares. The size of opaque squares 11 varies in a series of uniform graded steps. These increase from the smallest at the bottom to the largest at the top. The opaque and transparent squares in center block 5 are equal in area. Master transparent comparison squares 12 are located at either of the ends of the row of steps. Squares 12 have the same base density reading as the clear areas of the intermediate steps and are equal in area to all the other steps.

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 52% of the total text.

Page 1 of 2

Photographic Image Definition Tolerance Control Chart

Tolerance control chart 10, useful in photographic processing, comprises a plurality of individual halftone checkerboard patterns 1...9 each of the same over- all area. Each pattern consists of a like number of opaque and transparent squares. The size of opaque squares 11 varies in a series of uniform graded steps. These increase from the smallest at the bottom to the largest at the top. The opaque and transparent squares in center block 5 are equal in area. Master transparent comparison squares 12 are located at either of the ends of the row of steps. Squares 12 have the same base density reading as the clear areas of the intermediate steps and are equal in area to all the other steps.

Chart 10 is used as a monitoring device for each operation in a multiple step photographic process. In such a process high-contrast photographic materials such as the silver halides and high-contrast developers are used. As a preliminary to the use of chart 10 in the monitoring of a photographic process, each step of chart 10 is first measured for light transmissibility at different stages of exposure. The results are then calibrated into a chart as an aid in setting the developer stage at which the process is to be interrupted based on the development of a particular step in the chart. In one such photographic operation, chart 10, along with a circuit pattern to be developed, is projected and exposed onto a glass master. The circuit pattern and cha...