JPH06148411A - Production of mirror - Google Patents

Abstract

PURPOSE:To provide the specular surface which is suitable for computer control without requiring skill and can project intricate patterns as well in the process for production of the mirror with which reflected light is projected as bright and dark patterns on a screen when such collimated beams of light as solar rays are cast to the mirror even if the mirror has an ordinary smooth mirror finished surface with which a distortion is not admitted by naked eyes. CONSTITUTION:The distortion 5 for generating focusing or reflecting of the reflected light projected as a magic mirror phenomenon by the traveling irradiation with a high-energy density heat source, such as laser beam 2 or electron beam, in a manner as to make drawing is imparted to the surface of a mirror plate 1 consisting of thermally meltable materials, such as metals, plastics, glass and ceramics. The surface is subjected to finish polishing in the final at need. The distortion 5 is generated mainly according to the thermal expansion and thermal stress of the irradiated part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an ordinary smooth mirror surface that is not distorted by the naked eye, but when parallel light such as sunlight is applied, the reflected light is projected as a bright and dark pattern on the screen. The present invention relates to a method for manufacturing a magic mirror.

[0002]

2. Description of the Related Art The magic mirror has been introduced to the present day as a cast bronze mirror since the pre-Han Dynasty of ancient China (called a transparent mirror in China).
In Japan, similar mirrors depicting Amida Nyorai, characters, and statues of Mary began to be produced from the Edo period. Many speculations have been made about the method of manufacturing a magic mirror in this narrow sense. In addition, recently, a method of manufacturing a magic mirror in a broad sense, that is, a mirror for a magic mirror has been proposed (JP-A-1-31).
3009 publication).

Regarding the mechanism in which a bright and dark image is projected on a screen by a magic mirror, it is only 0.3 to 1.0 μm on the mirror surface.
Since the image pattern is formed by the lines of the depressions, it is known that the light is reflected by the depressions. That is,
Since the light is reflected and focused at the recessed portion, the projected image is made "bright" by the light focusing effect.

The most powerful view on the manufacturing method of the magic mirror is that the mirror is polished to be thin and the elastic deformation is utilized. According to this, when a pattern is formed on the back surface of the mirror by projection at the time of casting and the surface is polished while being elastically deformed by surface pressing, a dent (distortion) is generated on the surface in a thick portion that is difficult to deform, and a protrusion on the back surface is formed. A magic mirror reflection surface similar to the pattern is formed by the depression.

Contrary to this, the recent method for manufacturing a mirror for a magic mirror does not utilize elastic deformation at all, and after polishing the surface of the metal mirror plate, the surface is subjected to chemical treatment such as etching or press, By forming irregularities of a predetermined shape by mechanical processing such as casting, forging, die casting, etc. and then further polishing to make the irregularities extremely small, a smooth end plate with irregularities (distortion) that can not be seen with the naked eye is formed. To do.

[0006]

According to the ancient manufacturing method of the magic mirror, especially, the polishing of the surface takes a long time to perform the manual work, and the work requires a very skilled technique. Therefore, it is not suitable for mass production and the cost is high. Further, there are many mysteries in the manufacturing method, and even if the manufacturing is actually carried out on the basis of the inference, the dent becomes about 2-3 times deeper and cannot completely resemble a narrowly defined magic mirror. For more information on this, refer to “The origin of the magic mirror and its elucidation” in Magazine / Applied Physics, Vol. 61, No. 6 (1992).

Regarding the magic mirror phenomenon, that is, the reflection projection image is formed by a mirror surface that looks smooth to the naked eye, the condition of the depression necessary for that is that the depth is approximately 1.0 to 10 μm.
It is known that the range is m, so that it can be said that there is not much inconvenience even if there is a dent error of about 2 to 3 times as compared with the ancient magic mirror.

However, according to the ancient manufacturing method based on the inference, since there is a restriction that the degree of the depression cannot be freely adjusted, the projection distance of the image formation, the degree of darkness of the image formation, etc. can be freely set. It is difficult, it is difficult to meet various demands of consumers, and there is a similar problem in recent manufacturing methods.

A method using a chemical treatment or a machining method, such as a recent manufacturing method, has been proposed to solve the above-mentioned drawbacks of the manufacturing method of the magic mirror in a narrow sense, but in etching, Generally, it is inevitable to use a substance harmful to the human body (eg, etching solution such as FeCl ₃ ). Also, due to the corrosion resistance of the materials used, many processing conditions such as the type of etching solution, the temperature of the etching solution, and the etching time are different, making it difficult to analyze the data. It cannot be formed by numerically controlling the depth.

On the other hand, even if a mechanical processing means such as pressing or forging is used to form the unevenness, a complicated casting mold or an expensive mold is required. Moreover, since the allowable range of the unevenness of the unevenness is limited to 1.0 to 10 μm, it is technically difficult to form a mirror surface by machining, and the cost is inevitably high. In addition, since the distortion that forms the magic mirror reflection surface cannot be evenly distributed over the entire line, the image formation tends to be unclear at a predetermined projection distance.
The result is against the proposer's will.

The present invention has been made in view of the above circumstances.
Distortion of the magic mirror reflecting surface for converging or diffusing parallel light and reflecting it can be done by computer control requiring little skill, so it is suitable for inexpensive mass production, and the depth and degree of distortion or depression can be freely set. Therefore, it is an object of the present invention to provide a method of manufacturing a mirror that can clearly form a magic mirror image at a predetermined distance.

[0012]

In order to achieve the above object, the first invention is to irradiate a surface of a mirror plate made of a heat-meltable material with a high energy density heat source such as a laser beam or an electron beam. As a result, a method of manufacturing a mirror which imparts a distortion for converging or diffusing reflected light projected as a magic mirror phenomenon is configured.

According to the second aspect of the present invention, the pre-polished surface of the metal end plate is partially subjected to a heat treatment in which the laser beam is visibly irradiated and irradiated so as to be in a softened state at the initial stage of melting, and then final polishing is performed. Thus, a method for manufacturing a mirror is formed in which a distortion of a recess for forming a projected image in the heat-treated portion is formed by light.

[0014]

Since the mirror manufacturing method is configured as described above, when the surface of the mirror plate is irradiated with a high energy density heat source such as a laser beam or an electron beam, thermal expansion and
Since distortion due to thermal stress occurs, by finishing polishing as necessary, an uneven mirror surface that causes a magic mirror phenomenon can be obtained. The degree of strain is a condition that is easy to understand numerically, such as the ability of a laser processing device or an electron beam processing device that generates a high energy density heat source, irradiation traveling speed, etc., so data analysis and input of the results to a computer It is easy to operate and easy to control by computer.

Regarding the formation of strain, in the case of the second invention,
When the end plate is irradiated with a laser beam and drawn and run while controlling so that the irradiated part is not completely melted, the irradiated part is momentarily softened and the volume increases due to thermal expansion. At this time, the part that is not irradiated with the laser beam is cold and has not softened.
As a result of the expansion being constrained by the surrounding cold part, the irradiated part of the expanded laser beam rises so as to rise up due to plastic deformation. The compressive stress due to the cold portion at this time is almost absorbed by this plastic deformation. Then, when the irradiation of the laser beam is finished, the irradiated portion contracts in the opposite direction to form a minute recess.

As described above, after the irregularities are formed on the surface of the mirror plate, the discolored portion due to oxidation or the like at the time of processing the laser beam is removed by polishing to obtain a mirror surface which is recognized to be substantially smooth by the naked eye.

The unevenness on the mirror surface that produces the magic mirror phenomenon is
As described above, since the level difference is 1.0 to 10 μm, in the method by laser processing of the present invention, if the laser output that causes the unevenness in this range is calculated by the analysis by the finite element method, the magic mirror can be easily set due to the numerical limitation. A specular surface is obtained from which the phenomenon can be obtained.

Incidentally, with the development of computers, especially laser processing technology has made remarkable progress. For example, C
AD allows design development and conversion of figure data into numerical values in a very short period of time. On the other hand, by the finite element method,
If the physical properties of the material such as thermal conductivity and specific heat are given, the output of the laser beam that gives a certain strain can be calculated. By inputting the analysis results of these data to the laser processing device, it is possible to process the product much more easily than before.

[0019]

FIG. 1 is an explanatory view of a manufacturing method in an embodiment of the present invention, and the manufacturing procedure is shown in the order of (A), (B), (C) and (D).

Example 1 An end plate 1 as a material has a plate thickness of 2 mm and an area of 10 mm.
Using 0 mm x 100 mm S45C carbon steel plate (Fig. 1
(A)), and its surface is subjected to polishing in advance. A carbon dioxide gas laser processing device with an output of 900 W was used for irradiation with the high energy density heat source (FIG. 1 (B)).

The surface of the mirror plate 1 is irradiated with the laser beam 2 from a constant distance, and the speed is 0.4 m / min. In, the heat treatment was performed in a linear shape having a length of 50 mm. Then, the irradiated portion was melted and became a bulge 3 which was slightly higher on the upper surface (FIG. 1C), and the swelling 4 wider than the bulge 3 was generated on the lower surface because the melting spread to the lower surface. But,
The ridge 3 on the upper surface is instantaneous, and at the same time as the irradiation is finished, the ridge 3 is contracted by cooling and becomes a distortion 5 of the concave curved surface (Fig. 1).
(D)).

Since the processed portion is discolored by oxidation and can be seen with the naked eye, when it was polished almost uniformly over the entire surface, a smooth mirror surface where the processing was not visible to the naked eye was obtained.

When the sunlight is applied to the mirror surface of the magic mirror manufactured in this manner and the light is reflected on the white wall about 1 m away, a straight line is projected by "brightness" and the magic mirror phenomenon may be exhibited. It could be confirmed.

Example 2 A class 2 brass plate having a plate thickness of 2 mm and an area of 100 mm × 100 mm was subjected to an antireflection treatment in order to enhance the heat treatment effect, and the surface of the end plate 1 thereof had a carbon dioxide laser beam 2 of an output of 200 W. At a speed of 0.5 m / min. In 50, a straight line having a length of 50 mm was processed, the antireflection treatment material was removed, and then the discolored portion was polished to form a mirror surface which was recognized to be smooth to the naked eye.

Regarding the mirror for the magic mirror manufactured as described above,
It was confirmed that a magic mirror phenomenon occurred similarly when sunlight was applied to the white wall about 1 m away and the light was reflected in the same manner as in the above example.

When an electron beam processing apparatus is used to irradiate a high energy density heat source, the work procedure is almost the same as in the above embodiment, and in any case, it is operated by computer control. Further, the material of the end plate is not limited to metal as long as it can be melted by heat, and may be glass, plastic, ceramic or the like, and irregularities can be obtained in substantially the same manner. In the case of a mirror made of plastic or ceramic, a reflective layer can be formed on the surface by printing or vapor deposition of a reflective material.

[0027]

As described above, according to the present invention, there are the following excellent effects.

1) Since it is easy to obtain numerical data on the formation of the distortion of the magic mirror reflecting surface for converging or diffusing parallel light and reflecting the parallel light, it is suitable for computer control based on data analysis processing. A mirror surface can be formed by an operation that does not require skill, and its control makes it suitable for very inexpensive mass production of mirrors for magic mirrors.

2) In order to easily obtain the depth and degree of the distortion or the depression for forming the magic mirror image with high accuracy,
The magic mirror image can be clearly connected at a predetermined distance. Also,
Since the computer control is easy, the projection distance of the image formation, the pattern, etc. are free, and it is possible to obtain an extremely fine and complicated magic mirror image of a highly designed design.
It is also possible to meet the demand of consumers who desire higher quality and luxury.

3) Since a magic mirror surface is formed, it is not necessary to use a substance harmful to the human body such as an etching solution, and a safe working environment can be secured.

4) In order to form the distortion as the reflection surface of the magic mirror, it is not necessary to previously cast a convex portion on the back surface of the mirror plate, and neither chemical treatment nor machining is required. It is possible to perform precise machining of magic mirror surfaces apart from conditions that are difficult to capture numerically.

[Brief description of drawings]

FIG. 1 shows a procedure for manufacturing a mirror in the method of the present invention (A).
It is sectional explanatory drawing illustrated in order of each figure of (B) (C) (D).

[Explanation of symbols]

 1 End plate 2 Laser beam as a high energy density heat source 5 Strain

Front page continuation (72) Inventor Taiichi Sato 150 Nikamicho, Takaoka City, Toyama Prefecture, Toyama Industrial Technology Center (72) Inventor Toshihiro Koizumi 1-14 Otemachi, Takaoka City, Toyama Prefecture Koizumi Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A surface of a mirror plate (1) made of a heat-meltable material is irradiated with a high energy density heat source such as a laser beam (2) or an electron beam, and the reflected light projected as a magic mirror phenomenon by illuminating traveling irradiation. A method of manufacturing a mirror, which comprises applying a strain (5) for causing focusing or diffusion. 2. The pre-polished surface of the metal end plate (1) is partially subjected to a heat treatment for drawing and irradiating a laser beam (2) so as to bring it into a softened state in the initial stage of melting,
A method for manufacturing a mirror, characterized in that by performing finish polishing, distortion (5) of a dent for connecting a projected image with light is formed in a heat-treated portion.