JPH058534A - Hidden mark and its manufacturing method - Google Patents

Abstract

(57) [Summary] [Purpose] In everyday environments, a mark that cannot be visually identified is added to a product with a transparent or opaque mirror surface, and the output distribution is in the boundary region between ultraviolet light and visible light. Irradiate a light source to enable visual identification. [Structure] Marked parts are provided on the surface of the product with a mirror surface.
A slight indentation or bulge of 0.0 to 0.001 μm is formed, a partial difference in curvature is created, and reflected light is converged or dispersed to create a bright part and a dark part,
Identify the mark.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field which is identifiable under a specific condition and is usually called a hidden mark.

[0002]

2. Description of the Related Art Conventionally, when marking a trademark, a symbol, a number, or the like on a product or a part, it is a condition that they can be clearly identified, and it is necessary to give them a color contrast or to stamp them. It is marked by means such as. Marking points are set at prominent positions when a trademark or other advertising effect is required, but when facilitating product management from the manufacturing side, such as after-sales service or parts replacement, the prescribed contents are marked at inconspicuous positions. is doing.

[0003]

However, when the surface of a product or a component is required to have an extremely high mirror surface, the above-mentioned means cannot be used. There are some methods that can be identified only from a specific direction by using polarized light, and some are called watermarks that are used on paper, but when used for specular bodies, they cannot be used because they are harsh. .

The problem to be solved is
It is intended to provide a hidden mark that can be identified only under a specific light source and cannot be visually confirmed under a normal light source, and to provide an efficient method for producing the hidden mark.

[0005]

Hidden marks according to the present invention are various marks such as characters, images, trademarks, symbols or numbers that are difficult to read (image) under ordinary light sources such as natural light and electric light. The mark and the periphery thereof are mirror-finished, and the difference in dent or bulge of the mark itself with respect to the peripheral surface is 50.0 to 0.001.
It is in the range of μm, and the radius of curvature of the surface that causes the difference is set in the range of 0.1 to 10 ⁴ mm.

The hidden mark according to the second aspect of the invention is obtained by processing the hidden mark of the first aspect of the invention into a molding material and transferring it to a molded product.

Furthermore, the hidden mark as described above is rubbed against
It can be formed by printing, laser irradiation, electric discharge machining, or the like.

[0008]

In the first aspect of the invention, the mark itself is made into a mirror surface, and in order to converge or disperse the light beam, the mark surface becomes a minute concave mirror or convex mirror,
Due to the partial difference in the created curvature, it is almost impossible to identify the mark in everyday environment, but by irradiating with a light source with a short wavelength and a narrow range, for example, a black light, a metal halide lamp, etc. Can be identified.

In the second aspect of the present invention, for example, the mark formed on the frame of the spectacle lens is transferred at the time of molding of the molded lens, so that the mark can be provided without any obstacle even at a conspicuous position which is normally an obstacle. In this way, the molded product obtained by the molding die can be reliably distinguished from other companies' products.

According to the third aspect of the invention, it is possible to efficiently form a hidden mark suitable for each material to be marked on various mark-applied objects.

[0011]

[Embodiment 1] FIG. 1 is a perspective view showing an embodiment of the present invention. Reference numeral 1 is a concave metal mold for a lens, and 2 is a mark, which is usually invisible. FIG. 2 shows A of FIG.
The -A cross section is shown, and the surface of the mold 1 is covered with the metal film 3. The manufacturing method will be described. First, the surface of the metal mold 1 is ground into a predetermined curved surface. Then, polishing with a buff is performed until a fine uneven surface having a roughness of about 0.3 μm is obtained. Next, an iron brush with a Vickers hardness of about 600 having a spherical tip with a mirror surface with a radius of 0.5 mm is used, and the core pressure is 200 to 3
The mark 2 is marked by rubbing with 00 g. After that, light buffing is performed again, and after thoroughly washing, sputtering is performed. At the time of sputtering, first, etching at an output of about 400 W is performed for 20 minutes to make the edge portion of the mark gentle, and then a metal film 3 having a thickness of 1 μm is formed of a chromium-based metal by sputtering at an output of 2 KW. The mark 2 thus obtained has fine recesses and is given a mirror surface similar to that of the peripheral portion. This metal mold 1
The mark 2 above could not be visually confirmed under normal light, but the mark could be confirmed by irradiating with black light.

[0012]

Example 2 When a lens for eyeglasses was formed using the metal mold obtained in Example 1, the mark was not visible, but when the black light was irradiated, the mark could be confirmed. .

[0013]

Third Embodiment In FIG. 3, a glass mold 4 is sputtered with a thin metal film 5 of tin, nickel or the like to a thickness of 0.1 μm. The concave portion 6 is provided. After buffing this surface once, a Ta-based amorphous metal layer 7 was further coated thereon to a thickness of 0.5 μm. This state is shown in FIG. The fine recesses 6 of the mold 8 thus obtained show the same results as in Example 1,
The molded article produced by this also obtained the same results as in Example 2.

[0014]

[Embodiment 4] The surface of a metal mold similar to the metal mold 1 shown in Embodiment 1 is ground to a predetermined surface, and then the output wavelength is 10.6 μm.
After making a predetermined marking at a depth of 0.5 to 1.0 μm by using a CO ₂ laser of No. ₂ , a polishing with a buff was performed until fine irregularities with a surface roughness of about 0.3 μm were obtained. Next, the surface was thoroughly washed and then plated with nickel to a thickness of 1 μm to form a mirror surface. When a metal halide lamp was used as a light source on this surface, the marking portion was illuminated and the reflected light was projected on a screen at a distance of 50 cm, whereby the mark could be confirmed.

In the case of products other than the transparent body shown in the above-mentioned embodiment, the present invention can be applied to the mold used in the case of being manufactured by molding, so that it is not necessary to mark the position which is not particularly conspicuous. For other products having a mirror surface, such as glass, watch cases, spectacle frames, or other large products, it is also possible to locally form a polished surface and apply the mark of the present invention.

[0016]

According to the first aspect of the present invention, since the hidden mark is formed by utilizing a slight difference in curvature, even if the mark is normally provided in a conspicuous position, it is in a visible light region, that is, in a daily life. Since it is not visible under the light environment, it is possible to easily distinguish from other companies' products by entering the product name, manufacturing site, production lot, etc.

According to the second aspect of the present invention, it is useful to provide the lens or the plate-shaped transparent body, for example, and particularly in the case of a spectacle lens, when it is mounted on the frame, the portion used is the central portion of the lens. However, even if this hidden mark is provided in the center, it does not interfere with the use, and the provided mark can clearly prove the source even if trouble with other companies occurs, and in the case of orthodontic lenses for correction, It can also be used as a reference line for grinding positioning. Further, if the design of the mark takes into consideration the advertising effect and fashionability, the commercial value can be further enhanced.

According to the third aspect, it is possible to efficiently form a hidden mark corresponding to each material and property on the marking object.

[Brief description of drawings]

FIG. 1 is a perspective view of a lens mold having a hidden mark according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a cross-sectional view in an intermediate step when applying a hidden mark of the present invention to a glass mold.

FIG. 4 is a sectional view of a finished product in which a hidden mark of the present invention is applied to a glass mold.

[Explanation of symbols]

1 mold 2 mark 3 metal film 4 glass mold 5 Metal thin film 6 Fine recess 7 Amorphous metal layer 8 mold

Claims (3)

[Claims] 1. A place where various marks such as characters, images, trademarks, symbols, or numbers that are difficult to read (images) under ordinary light sources such as natural light and electric light are entered and their surroundings. The difference in the dent or bulge of the mark itself from the peripheral surface is 50.0
A hidden mark having a range of ˜0.001 μm and a radius of curvature of the surface that causes the difference is set to a range of 0.1˜10 ⁴ mm. 2. A hidden mark obtained by processing the hidden mark according to claim 1 into a molding material and transferring it to a molded product. 3. A method for producing a hidden mark, which is formed by a forming means such as rubbing, printing, laser irradiation, electric discharge machining or the like.