JPH026363Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a test pattern used in a device that detects flaws by photographing flaw patterns caused by magnetic particles observed in magnetic particle flaw detection using an industrial television camera or the like.

In such magnetic particle flaw detection, flaws and magnetic particle patterns detected by magnetic particle flaw detection are photographed with a television camera, image processing is performed, and flaws are determined. At this time, it is required to check the performance of the television camera. In other words, the method of checking is to create an artificial pseudo-pattern that resembles the actual scratch pattern, and to photograph this using a television camera for diagnosis. In this case, there are differences in performance of the fluorescent magnetic powder used for the actual scratch pattern due to differences in manufacturers, etc., and this difference is due to color tone, fluorescence brightness, particle size,
There are other factors, but among these, the brightness, which is the signal level, is the most important in terms of the performance of the television camera. Therefore, unless the test pattern is made to have the same brightness as the magnetic powder used, it will not serve as a pseudo flaw pattern.

The object of the present invention is to provide a test pattern for checking the performance of a television camera or the like used to photograph a luminescent scratch pattern.

The feature of the present invention is that an artificial pseudo-scar pattern is created using a material that emits light when irradiated with ultraviolet light, and the amount of ultraviolet light applied to the pattern can be adjusted. Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a perspective view showing a situation in which a scratch pattern is photographed with a television camera. In the figure, 1 indicates an object to be inspected, 2 indicates a television camera, 3 indicates ultraviolet light, and 4 indicates a flaw pattern emitted by light. In addition, in the figure, the means for supplying the magnetic powder liquid is omitted from illustration.

FIG. 2 is a perspective view showing an example of a test pattern according to the present invention. In the figure, 1' is a substrate made of a suitable material, 4' is a pseudo scratch pattern formed on the substrate 1' with a material that emits light when irradiated with ultraviolet light, and 5 is a light shielding piece for adjusting the amount of ultraviolet light. It is. The length and thickness of the pseudo scratch pattern 4' are set to various values to resemble the actual scratch pattern. These test patterns are irradiated with ultraviolet light and photographed with a television camera, but since the amount of light emitted varies depending on the type of magnetic powder, it is necessary to always obtain the optimal test pattern image even if the type of magnetic powder changes. It is necessary to Therefore, in this example, light shielding pieces 5 are provided which can adjust the amount of light by blocking the optical path of the ultraviolet light irradiated on both sides of the pseudo scratch pattern 4'. In the figure, only one pair of light-shielding pieces 5 is shown for simplicity, but the light-shielding pieces 5 are provided corresponding to each pseudo-flaw pattern 4'.

FIG. 3 is a sectional view showing the operation of the embodiment of FIG. 2. In the figure, the same reference numerals are given to the parts already described. The light shielding piece 5 can change the amount of light irradiated onto the pseudo scratch pattern 4' depending on its position. Therefore, the position of the light shielding piece 5 is adjusted as shown by the arrow in the figure, and the light shielding piece 5 is fixed at a position where an optimum test pattern image can be obtained. Various methods can be used to adjust and fix the position of the light shielding piece 5, and any method may be used.

Note that the relative value of fluorescence brightness is usually displayed on fluorescent magnetic particles by the manufacturer. Therefore, by attaching a scale corresponding to the relative fluorescence brightness value to the light-shielding piece 5 that adjusts the amount of light incident on the test pattern described above, and adjusting this, it is possible to calibrate the light to emit light equivalent to the fluorescence brightness of the magnetic powder.

Further, in this example, the pseudo scratch pattern 4' is fixed and the light shielding piece 5 is moved, but the light shielding object may be fixed and the scratch pattern 4' is moved.
An example is shown in FIG.

In FIG. 4, 5' indicates a light-shielding layer such as black Bakelite formed on the substrate 1', and 6 indicates a screw for moving the position of the pseudo scratch pattern body 4'' up and down.By turning the screw 6, The amount of light irradiated can be adjusted by raising and lowering the pseudo-scar pattern body 4''.
One or more screws 6 are provided for one pseudo-flaw pattern body 4''.

As explained above, according to the present invention, the amount of ultraviolet light irradiated onto the pseudo-flaw pattern can be arbitrarily adjusted according to the type of magnetic particles, and even if the type of magnetic particles changes, the optimum brightness is always maintained. Since a test pattern image can be obtained, the present invention is suitable as a flaw pattern test pattern for checking the performance of a television camera or the like actually used for photographing flaw patterns.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing how a scratch pattern is photographed by a television camera, Fig. 2 is a perspective view showing an embodiment of the present invention, Fig. 3 is a sectional view showing the operation of the device shown in Fig. 2, and Fig. 4. FIG. 2 is an enlarged sectional view of a main part showing another embodiment of the present invention. 3...Ultraviolet light, 4', 4''...pseudo scratch pattern,
5, 5'... Light blocking object.

Claims (1)

[Scope of utility model registration request] It consists of a pseudo scratch pattern formed by an object that emits light when irradiated with ultraviolet light, and a light shielding object that is placed near the pseudo scratch pattern and can reduce the amount of ultraviolet light irradiated to the pseudo scratch pattern. A test pattern used for magnetic particle flaw detection in which the amount of light emitted from the pseudo flaw pattern can be adjusted by adjusting the amount of ultraviolet light irradiated onto the pseudo flaw pattern using a light shielding object.