Japan E.m. Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Hiroki Hoshiyama

Yoshio Kanata

Nobumichi Munesada

Michitaro Horiuchi

A scale has marks of a point-symmetrical shape which are arranged in matrix. The scale and an article to be measured in dimension are positioned without any relative movement. An image sensor unit detects a predetermined portion of the article and the marks of the scale corresponding to the predetermined portion of the article selectively and successively, and the image sensor unit generates output signals in accordance with the detected results of the article and the scale. The output signals are processed to calculate the dimension of the article.

Scale for measuring dimension of article and scale to be used in the same

Apparatus for measuring dimension of article and scale to be used in the

A method for accurately obtaining, in a short period of time, the position and slope of a specific edge line, even when there are many extraneous points caused by dust and other such garbage or electrical noise around the edge line to be obtained. A window covering the area containing the desired edge line is set, and the area inside the window is scanned at a specific interval in a direction crossing the edge line so as to obtain specific image data. The coordinates of points indicating a change in brightness in the scanning direction are obtained as edge points. The area inside the window is divided into a group of rectangular subareas parallel to the edge line to be detected and at a predetermined pitch and size capable of containing the edge line. The subarea containing the greatest number of edge points is obtained, and the edge line is then estimated from the coordinates of the edge points in this subarea containing the greatest number of edge points.

Edge line measuring method

A scale has marks of a point-symmetrical shape which are arranged in matrix. The scale and an article to be measured in dimension are positioned without any relative movement. An image sensor unit detects a predetermined portion of the article and the marks of the scale corresponding to the predetermined portion of the article selectively and successively, and the image sensor unit generates output signals in accordance with the detected results of the article and the scale. The output signals are processed to calculate the dimension of the article. An apparatus for measuring the dimension of an article is provided which can eliminate the occurrence of parallax, resulting in satisfactorily improved precision of the measurement. In the apparatus, an article and a marker are disposed so that the optical distance between the article and a reading unit is equal to the optical distance between the marker and the reading unit.

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Hamamatsu, Japan

Hiroki Hoshiyama