PROJECTING SYSTEM FOR DETECTING FOCAL POINT

摘要

PURPOSE:To permit focusing with high accuracy by providing fine lines to a specific one part of a stripe pattern and making focusing by visually checking the fine lines. CONSTITUTION:The patterns 6 are constituted of stripe shapes in the direction orthogonal with a photoelectric transducer array 12 and short transmission parts 1-3 (fine lines or spacings) orthogonal or parallel with the array 12. The focusing of the pattern 6 is then executed by visually observing the pattern 6 projected onto a screen placed in a reference position and checking whether the fine lines 1-3 formed with slight spacings placed between each in one part of the pattern 6 are resolved or not and whether the spacing provided perpendicularly to the narrow spacing (transmission part) or filament between the two fine lines is distinct or not. The pattern image projected onto a subject surface 4 is sharp and is in a high contrast state if the narrow spacing of the two fine lines in the pattern 6 can be visually and distinctly checked. The focusing with the high accuracy is thereby permitted.