JPS592068B2 - Zukeihikakukensa Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus and a method for comparing and inspecting figures manufactured as identical figures based on a reference figure for manufacturing defects.

Conventionally, optical systems and electrical systems have been widely used as graphic comparison inspection devices and methods.

As an optical method, a slit or a polarizing element is interposed in each optical path that is set by combining optical components such as lenses, reflectors, and half mirrors so that the axes of the optical paths emitted from the reference figure and the figure to be inspected coincide. When the figures are visually observed at a location where the optical path axes coincide, the slit or polarizing element is operated so that the reference figure and the figure to be inspected are observed alternately, and the differences between the two figures are taken into close-up. . The electrical method uses a photoelectric detection element, and a scanning station is constructed by combining a light emitting part and a light receiving photoelectric detection element, and a reference figure and a figure to be inspected are set in the middle of each optical path, and each photoelectric detection element The output signals of the two are compared to perform a graphical comparison. However, with these conventional devices,
The optical method (1) detects the reference figure and the figure to be inspected alternately, so it is impossible to prevent flickering of the image that occurs when switching, and (2) it is impossible to detect minute differences in the entire projected figure. Also, since the electrical method is a mechanical scanning method, there is a limit to the scanning speed, (there is a difference in detection accuracy depending on the direction of the two scans, and (3) the difference is that the line segment in the scanning direction However, with the advancement of television technology, the resolution, characteristics, and sensitivity of image pickup tubes have improved, and their value as industrial image pickup tubes has been reconsidered. As a method using industrial television technology in the figure comparison inspection method, an electron beam scans the same corresponding parts of the reference figure and the figure to be inspected, which are set opposite to the image pickup camera, on the image pickup surface of the image pickup camera. Devices and methods are being considered that compare the output signals from each camera at different stages and detect parts with different signal characteristics.

However, in this method, the image pickup tube built into each camera device itself contains its own distortion, and depending on the required detection accuracy, the figure itself may be deformed due to the two-dimensional internal distortion. Therefore, the area of the difference between the detected figure and the reference figure is required to be larger by an amount of light than the amount of strain between the imaged bones, and as a result, the figure must be enlarged for observation. Therefore, there was a limit to the area of figures that could be compared at one time. The present invention takes into consideration the above drawbacks, and
An object of the present invention is to provide a figure comparison inspection device using a color imaging method.

That is, in the present invention, images of both a reference figure and a figure to be inspected, which are fixed in a certain positional relationship, are overlapped on the same imaging plane by two optical systems with filters of different primary colors interposed in their respective optical paths. Out of the output signals of one color imager placed at the position where the image is projected, the reference figure is detected by electrically comparing two signals corresponding to two primary color lights corresponding to the reference figure and the figure to be inspected. The object of the present invention is to provide a figure comparison inspection device that uses a color imaging method to detect differences between the figure and the figure to be inspected. Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. 1st
In the figure, a reference figure 11 and a figure to be inspected 21 are fixed using a pin adapter method or the like to maintain a fixed positional relationship, and lenses 12, 22, 1 are placed facing each figure.
6. Using mirrors 13, 23, 15, half mirror 25, etc., the optical path axis 10 of the reference figure 11 and the figure to be inspected 21,
The respective optical components are combined and set so that the optical components 20 pass through the lens 16 and are aligned at the optical path axis 26.

On the optical path axis 26 after passing through the lens 16, images of the reference figure 11 and the figure to be inspected 21 are captured by the color imager 17.
In this case, the images will be observed in duplicate as shown in FIG. 231. Therefore, if an image pickup device for detecting a figure is set on this optical path axis 26, the output signal of the image pickup device becomes a signal of the figure 2, 31, which overlaps the reference figure 11 and the figure 21 to be inspected.
On the other hand, filters 14 and 24 for different primary colors are provided in the optical paths 10 and 20 of the reference figure and the figure to be inspected (for example, the filter 14 is for blue light and the filter 24 is for green light).
When interposed, the reference figure is observed as a blue bright/dark figure on the optical path axis 26, and the inspected figure is observed as a green bright/dark figure. Here, the reference figure and the figure to be inspected should have originally been manufactured as the same figure, and the optical path axis 2
When observing in step 6, finely adjust the fixed positions of the two figures and the fixed positions of lenses, mirrors, etc. placed in the middle of each optical path axis so that the two figures are observed completely overlapping. There is a need. When the color imager 17 is set at the end of the optical system assembled as described above, that is, at the overlapping optical path axis, the color imager displays the reference figure as a blue pattern and the inspected figure as a green pattern. , and the two figures are projected in an overlapping form as shown in FIG. 231.

Therefore, by comparing the blue signal 32 and green signal 33 of the figure photographed by the color imaging device, it is possible to compare the reference figure and the figure to be inspected. The imaging device employed here is preferably a single-tube or two-tube type, rather than the conventional three-tube or four-tube color imager. 2
In the case of a tube type, attention is focused only on a vidicon that extracts two primary colors, and generally red light and blue light are used.

Further, as a single tube type, a frequency multiplexing method using individual frequencies for each color optical signal or a single frequency multiplexing method using shifted phase angles may be used. In this way, the reference figure and the figure to be inspected are photographed in an overlapping form as images through different color light filters.Among the three primary color light signals that have passed through the matrix circuit of the color imager, the primary colors adopted as the filters are Light signals For example, in FIG. 1, if a blue light filter is used as the filter 14 and a green light filter is used as the filter 24, the blue signal and green signal from the color imager are focused on the imaging surface of the imaging tube. The electrical signals correspond to the blue and green illuminance of the optical image when the electron beam is repeatedly moved in the vertical direction while scanning the optical image in the horizontal direction. Therefore, the blue signal represents the illuminance of the reference figure, and the green signal represents the illuminance of the figure to be inspected, and these two signals have the same shape when the reference figure and the figure to be inspected match. However, if there is a difference between the two figures, it will appear as a time lag in the signals as the electron beam scans. This time shift is detected and synthesized as a surface on a monitor, and detected as a difference between the reference figure and the figure to be inspected. In this case, the color image pickup tube has stripe filters arranged at a constant pitch to separate the primary colors, so the color shift caused by this is corrected. Dirt is also picked up as noise, so after shaping the waveform by adding a shaping circuit to clearly separate the graphic and non-graphic parts, it is applied to a comparison circuit such as a differential amplifier or an exclusive OR circuit. Must be entered. Here, since the signal that has passed through the comparison circuit is a mere pulse waveform, it is input to the monitor through a converter while being synchronized with the scanning cycle of the color image pickup device, and the areas are synthesized to form a comparison figure 35.

This comparison figure 35 is an exclusive OR combination of the reference figure 11 and the figure to be inspected 21, and the different parts between the figures are displayed as bright parts 35a, and the figure parts of both figures are Or it is contrasted with a part that is a non-graphic part.
However, if only the comparison figure is used, even if the difference is displayed, it is difficult to correlate it with the figure to be inspected. Therefore, in order to superimpose the comparison figure on the figure to be inspected, the ratio and contrast between the comparison figure signal from the differential circuit input to the monitor and the figure to be inspected signal from the shaping circuit are controlled by a switch or the like. Also, the difference 35a between the shapes detected on the monitor soil
As a method of directly feeding back the data to the figure to be inspected, an X-Y plotter can be used as a terminal of the system in the figure to be inspected setting section. In this way, the present invention completely automates the comparative inspection process of figures, which in the conventional apparatus and method always relied on Iruma's naked eye. Detection can be exaggerated, so there are fewer detection errors, detection accuracy can be freely set by inserting an optical filter, shaping the imager output signal, etc. Because it is performed by scanning an electron beam, the inspection speed is faster than mechanical scanning methods, and it has many advantages, such as eliminating distortion of the image pickup tubes, which is a problem when using multiple image pickup tubes. This is a comparative testing method.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram showing an embodiment of the present invention, and FIG. 2 shows a signal model and comparative figures during figure scanning according to the present invention. Codes in the figure: 11: Reference figure, 21: Inspection figure, 12
, 22, 16: Lens, 13, 23, 15: Reflector, 2
5: Half mirror 1, 17: Kara 1 imager, 32, 33:
Output signal of color camera, 34: Comparison circuit output signal, 3
5: comparison figure, 14, 24: primary color filter one.

Claims (1)

[Claims] 1 Images of both the reference figure and the figure to be inspected, which are fixed in a certain positional relationship, are projected onto the same imaging surface in duplicate by two optical systems with filters of different primary colors interposed in their respective optical paths. The reference figure and the figure to be inspected can be detected by electrically comparing the signals corresponding to the two primary color lights corresponding to the reference figure and the figure to be inspected among the output signals of one color imager placed at the position where the figure is to be inspected. A graphic comparison inspection device that displays differences between the two as bright areas on the monitor.