Dainippon Screen Mfg. Co., Ltd.

Dainippon Screen Seizo Kabushiki-kaisha

Tetsuo Sano

Takashi Sakamoto

Eiji Kodama

Hisayuki Tsujinaka

Ryuji Kitakado

Tetsuo Hoki

Yoshio Ono

Tetsuo Hohki

Hiroyuki Onishi

Takumi Yoshida

Takao Omae

Yoshinori Sezaki

Tomiji Hotta

Hironobu Yano

Masafumi Kawatani

Isao Teramae

Masamichi Choh

A defect inspection apparatus inspects a defect by a compare check method even if there is only one object substrate to be inspected. Further, if there are a plurality of object substrates to be inspected, the defect inspection apparatus corrects a reference pattern image in accordance with defect inspection using the compare check method. In application to a printed to wire board on which identical unit patterns are printed, unit patterns which are included in one row are defined as a mater area and the other unit patterns on the same printed wire board are defined as object areas. The master area is compared with each one of the object areas to thereby perform defect inspection. When there are a plurality of object substrates to be inspected, a pattern image is corrected utilizing results of comparison. By using a corrected pattern image as a master substrate image, defect inspection is performed on the other object substrates.

Method of and apparatus for inspecting pattern defects

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.

Method of and apparatus for detecting pattern defects

Printed wiring boards (PWBs) applied to this inspection system are previously formed with marks in prescribed positional relation to wiring patterns. Deviation of PWBs with respect to absolute coordinates of the inspection system is detected by reading the marks. The PWBs are sequentially set one by one on a movable table, to be subjected to image acquisition of the marks and inspected areas. A first PWB is image-acquisited whereby obtained binary image data of the inspected area are stored in a memory unit. Thereafter a second PWB is image-acquisited, and in advance to the image acquisition of its inspected area, relative misregistration of the both PWBs is found by deviation data on respective marks of the first and second PWBs. The binary image data of the first PWB is read from the memory unit on the basis of the binary image data of the second PWB. When the binary image data of the first PWB are read, positional correction, i.e., time base correction is performed on the read data to correspond to pixels of the second PWB under image acquisition on the basis of data on the previously found amount of relative misregistration. The data on corresponding pixels of the both PWBs are compared with each other thereby to inspect difference between the patterns of the PWBs on the basis of the result of the comparison.

System for inspecting pattern defects of printed wiring boards

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.

Pattern masking method and an apparatus therefor

Disclosed herein is an image pickup apparatus for a printed wiring board comprising a solid state image sensor whose light receiving surface is set to be opposed to the surface of the printed wiring board, a main illumination source arranged to satisfy the law of regular reflection on the surface of the printed wiring board with respect to the light receiving surface of the solid state image sensor and a subsidiary illumination source arranged not to satisfy the law of regular reflection with respect to the light receiving surface of the solid state image sensor thereby to supply the light receiving surface with scattering light by strias formed on copper patterns. The amount of regularly reflected light, which is changed depending on the strias formed on the copper patterns, is substantially compensated by the scattering light, so that the amounts of light received by the solid state image sensor relating to the copper patterns are made substantially constant regardless of the radiation pattern of the strias. In addition, the main and subsidiary illumination sources are formed by light emitting diodes thereby to attain technical and economical advantages.

Image pickup apparatus for a printed wiring board

A method for scanning and recording a plurality of original pictures by a picture reproducing machine in which desired parts of said plurality of original pictures of different reproduction magnification are simultaneously input and scanned, and at least parts of the desired portions are stored into memory so that they may be output, scanned and recorded simultaneously with different magnifications.

Method for scanning and recording a plurality of original pictures

An apparatus for tracing and recording image lines includes a coordinate reader which detects coordinate values of an image to be traced; an image sensor which is movable in a plane relative to a table; a memory in which image signals detected by means of the sensor are written; and a central processing unit which controls the above elements of the apparatus. Trace data are obtained by means of the coordinate reader which detects coordinate values of the image lines. Then, the image is positioned on the table, where record data are obtained based on the trace data by means of the image sensor which generates image signals corresponding exactly to the image.

Method of tracing/recording image lines and apparatus therefor

A picture scanning and recording system in which a scanning for 'sharp' signals and a scanning for 'unsharp' signals are alternately conducted, each in half periods of scanning, by means of a common photoelectric converter. One of these two series of signals is temporarily stored in a memory for synchronous processing with the other series of signals that is just being produced in such a manner that no inconformity is brought about into recording signals of detail contrast.

Method and apparatus for picture signal enhancement

A method for producing a halftone plate from an original picture having a continuous tone. A record film is exposed at least one exposure light beam of a smaller size than a halftone dot area by independently controlling it to turn on or off according to a picture signal. The luminous energy of the exposure light beam is controlled depending on a reference value corresponding to the picture signal and a position signal value varied depending on an exposing position in the halftone dot area to be exposed by the exposure light beam. The control of the luminous energy is performed by the sum, the difference, the product or the quotient of the two signal values. A plurality of reference values or position signal values may be used.

Method for producing a halftone plate

A method for tracing an object such as an outline of a picture or a line image, wherein the object is sensed by a set of sensing elements arranged in an optical head moving along the object, to detect a position and a direction of the object, wherein the optical head is controlled to trace the object depending on the detected position and the direction of the object, and wherein the object is reproduced by reproduction means which is moved in synchronization with the optical head. Present invention improves this method by moving the optical head along portions of the object, which the sensing elements can discriminate hardly or not at all nor follow the object, according to line segment data which is predetermined and represent a plurality of points of coordinates.

Method for tracing an object

A method and machine for positioning films on base sheets is disclosed. A first film on a base sheet is laid out into a desired position on a base plate, and positions of register marks attached on the first film are detected by photoelectric detectors including photoelectric elements which detect the register marks and output signals whose strengths are varied depending on the positions of the elements with respect to the register marks. Then, a second film on a base sheet is put on the first film so that the register marks on the second film, which are marked in the same positions as those of the first film, may approximately overlap those register marks of the first film, and the register marks of the second film become coincident with those of the first film by moving the second film by means of a drive means according to the output signals from the photoelectric elements, thereby positioning the second film into the desired position.

Method and machine for positioning films on base sheets

A method and machine for positioning films on base sheets are disclosed. A first film on a base sheet is laid out into a desired position on a base plate, and positions of edges of a picture pattern on the first film are detected by photoelectric detectors including photoelectric elements which detect the edges and output signals whose strengths are varied depending on the positions of the elements with respect to the edges. Then, a second film on a base sheet is put on the first film so that edges of a picture pattern of the same shape as in the first film, on the second film may approximately overlap to those of the first film, and the edges in the second film are completely coincided with those in the first film by moving the second film by means of a drive means according to the output signals from the elements, thereby positioning the second film into the desired position.

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Kyoto, Japan

Tetsuo Sano