Abstract: In a printed substrate inspection apparatus for dividing an inspection objective image into divided areas and comparing divided areas with a plurality of reference images which are included in a standard pattern image, an affect of a positional deviation of the inspection objective image is obviated. A size K of each inspection objective divided area is determined in such a manner that a difference between a positional deviation within each inspection objective divided area and a positional deviation of the inspection objective image does not exceed a quantity corresponding to 1 pixel. Further, a maximum shifting quantity M of the reference images with respect to each inspection objective divided area is set equal to or larger than a positional deviation maximum value of the inspection objective image. A positional deviation of the inspection objective image as a whole does not manifests itself as an inclination or a distortion within each inspection objective divided area.

Abstract: A printed pattern is provided with a wiring pattern having a land and a through hole surrounded by the land. The wiring pattern and the through hole are read by a photoelectric image sensor to obtain a pattern image and a hole image, respectively. A pattern gauge image is defined by the pattern image, and a hole gauge image having a ring-like shape is obtained from the hole image. A logical product between the inversion image of the pattern gauge image and the hole gauge signal provides a protrusion region image. Since the hole gauge image has an isotropic contour, the minimum annular width of the land is detected, independent of the direction in which the through hole is deviated from the land.

Abstract: A printed board, on which a wiring pattern and a through hole to be inspected are provided, is scanned pixel by pixel and is read optically. The data obtained by scanning is converted into an electric signal to obtain image data. On the basis of the image data thus obtained, a pattern image representing the wiring pattern an a hole image representing the through hole are obtained. A center and a radius of the hole image are obtained from the image data. Then, a plurality of ring-shaped masks are obtained by magnifying the hole image at a plurality of magnifications. The size of the pattern image is normalized by the size of the hole image, and the, respective areas of overlapped regions between a plurality of the ringshaped masks and the pattern image are detected. Since these areas are obtained with an isotropic method, they do not depend on the directions of a line entering a land.

Abstract: The image of a wiring pattern provided on a printed board is obtained and binarized. A square pixel operator comprised of a matrix of pixels is applied to the pattern image. Pixel trains extending in different directions are extracted from the result of applying the square operator. The numbers of pixels having the binary value "1" on the pixel trains are counted to obtain the respective sizes of the pattern image on the pixel trains. Signals representing the respective sizes are subjected to timing adjustment operation and to obtain the width of the wiring pattern on an area larger than the square operator.

Abstract: A set of red light sources (111-113) are provided above a printed board (20). One (111) of the light sources located in the angular aperture of an imaging lens system (140). The red light is applied to the printed board and reflected on a wiring pattern (22) provided thereon. Another light source (120) is provided under the printed board, and emits infrared light to the back surface of the printed board. The infrared light passes through a through hole (25) formed in the printed board and then enters the imaging lens system together with the red light reflected. Compound light consisting of the red light and the infrared light passes through the imaging lens system and is then splitted into the red light and the infrared light at a cold mirror (150). The respective lights are detected by image sensors (161, 162), to thereby obtain respective images of the wiring pattern and the through hole.

Abstract: Respective images of a conductive pattern and through holes of a printed circuit board are obtained. The through holes are classified into normal through holes having a relatively large diameter and mini via holes having a comparatively small diameter. The mini via hole image is enlarged to become an enlarged mini via hole image (SHSm). The image of the conductive pattern has hole parts therein, which are filled with images generated from the normal through hole image and the mini via hole image to obtain a corrected pattern image (CPS). The edge of the corrected pattern image is detected and enlarged to obtain an enlarged edge image (SES). The enlarged edge image is classified into two areas, one of which overlaps with the enlarged mini via hole image (SHSm). These two areas are subjected to inspection in different inspection modes.

Abstract: A printed circuit board (11) is provided with a conductive pattern (P, R) and a through hole (H) thereon. Respective images of the conductive pattern and a through hole are photoelectrically read with an image reader (20). The conductive pattern image is magnified in size to obtain a magnified pattern image (PI.sub.m), while the hole image is magnified at different magnification factors to obtain magnified hole images (HI.sub.n, HI.sub.n-i). A ring image (RP) is defined by the difference of the magnified hole images. The overlapped region (WR) on which the ring image and the magnified pattern image overlap each other is then calculated, and a defect or an opening of the conductive pattern is detected by calculating the aperture angle (.theta.) of the overlapped image.

Abstract: An objective printed circuit board to be inspected has a printed conductive pattern (550) thereon. The image of the objective printed board is read with an image reader to obtain an image signal. Prior to the image reading of the objective printed board, a reference printed board of the same type as the objective printed board is prepared, and the image thereof is read with the image reader. An edge image of a conductive pattern on the reference printed board is extracted and enlarged to generate an enlarged edge image (SEI). In inspection of the objective printed board, only areas belonging to the enlarged edge image are actually inspected and other areas are not subjected to the inspection.

Abstract: A printed circuit board (11) is provided with a conductive pattern (P, R) and a through hole (H) thereon. Respective images of the conductive pattern and a through hole are photoelectrically read with an image reader (20). The conductive pattern image is magnified in size to obtain a magnified pattern image (PI.sub.m), while the hole image is magnified at different magnification factors to obtain magnified hole images (HI.sub.n, HI.sub.n-i). A ring image (RP) is defined by the difference of the magnified hole images. The overlapped region (WR) on which the ring image and the magnified pattern image overlap each other is then calculated, and a defect or an opening of the conductive pattern is detected by calculating the aperture angle (.theta.) of the overlapped image.

Abstract: An apparatus for inspecting pattern defects in circuit board conductors or other images has inspecting units which perform inspection operations based on various pattern matching approaches, which include design rule checking and expansion/contraction processing. Each of the inspecting units inspects a part of the pattern of an object. The part of a pattern is defined by a respective inspection and inhibition domain defining signals. The domain signals are formed with the aid of a scanning device and a binarizing circuit, a CAD system and a converter, a digitizer and a converter and the like. The apparatus then displays inspection decisions derived from each inspecting unit on a display unit, with respect to the different domains.

Abstract: A printed circuit board (11) is provided with a conductive pattern (P, R) and a through hole (H) thereon. Respective images of the conductive pattern and a through hole are photoelectrically read with an image reader (20). The conductive pattern image is magnified in size to obtain a magnified pattern image (PI.sub.m), while the hole image is magnified at different magnification factors to obtain magnified hole images (HI.sub.n, HI.sub.n-i). A ring image (RP) is defined by the difference of the magnified hole images. The overlapped region (WR) on which the ring image and the magnified pattern image overlap each other is then calculated, and a defect or an opening of the conductive pattern is detected by calculating the aperture angle (.theta.) of the overlapped image.

Abstract: The periphery of an area of a master pattern is expanded by a required number of pixels to define a plurality of master pattern areas two-dimensionally misregistered pixel by pixel, for performing pattern comparison of the respective master pattern areas with an area of an object pattern. The object pattern is deemed defective when all of the comparisons indicate pattern mismatches. The pattern is deemed not defective when at least one comparison indicates a pattern match. Thus, even if an inspected object includes misregistration errors, pattern defects can be detected with high accuracy.

Abstract: A binarized image data group of an inspected object for a plurality of pixels arrayed in the sub-scanning direction is sequentially created in order along the main scanning direction to determine whether or not the pattern of an inputted image corresponds to a standard through-hole pattern on the basis of the binarized image data group. When the determination is of yes, through-hole diameter masking data are sequentially created in order along the main scanning direction to sequentially perform masking processing on the binarized image data group of the inspected object arrayed in the sub-scanning direction. Thus, the through-hole pattern is automatically detected to be subjected to masking processing, whereby an inspected object having through-holes can be inspected by a pattern matching method.