| 摘要 |
PURPOSE:To make it possible to measure the dimension of a tooth form to be measured on the basis of a projected light from or pitch formed by recessed and protruded parts, by providing proper recessed and protruded parts to the tooth form opposed surface of a light blocking rule. CONSTITUTION:When light is emitted from a light source 3, the light advancing to the tooth trace direction of a tooth form 2 passes between a light blooking rule 1 and the tooth form 2 while forms light and parts shown by a projected light imaginary cross-section A. As shown in a drawing displaying a wedge shaped Z-part of the projected light imaginary cross-section A in a magnified state, projected light form parts 31a, 32a, 33a corresponding to the recessed parts of the light blocking rule are formed to the projected light imaginary cross-section A. One or both of the pitch dimension and shape of the projected light form part 31a (32a, 33a) and a tooth form shape part 2a are taken in a light receiving apparatus 5 through a light receiving part 6 to be converted to electric signals which are, in turn, transmitted to an image processing substrate not shown in a drawing to measure the dimension of the tooth form to be measured. |
