JP2005247603A - Method for processing glass article or crystallized glass article and method for producing the article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a glass or crystallized glass member (e.g., reflecting mirror) to drill or cut it, which method can be carried out without using water and can therefore make it possible to eliminate the formation of water spots, to provide an improved yield and improved quality, and to dispense with washing and drying steps otherwise performed after the processing. <P>SOLUTION: The method for processing the glass article or the crystallized glass article comprises the step of molding the article so that that part of the article which is processed later may have a wall thinner than the remaining part of the article and drilling or cutting the part by irradiation with laser beams. It is desirable that the part to be processed has a wall thickness of at most 3 mm, and that the coefficient of thermal expansion of the raw material is at highest 55×10<SP>-7</SP>/°C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a processing method and a manufacturing method for glass products or crystallized glass products. In particular, the present invention relates to a reflecting mirror incorporated in a projector, a projector, a lighting device, and the like, and a method for manufacturing a fly-eye lens.

  The reflecting mirror selectively and efficiently reflects only the visible light of the light source lamp forward by a multilayer reflecting film formed on the inner surface of the reflecting mirror. Since excellent heat resistance and thermal shock resistance are required, heat resistant glass and super heat resistant crystallized glass are used as the substrate material.

  The fly-eye lens is a lens body (lens array) in which single lenses are arranged vertically and horizontally, and is called a fly-eye lens because its appearance resembles an eyelid. It is used to disperse the luminance unevenness of the light source and obtain a uniform illuminance distribution on the irradiated surface. As a substrate material, heat-resistant glass is often used.

  A reflector made of glass or crystallized glass requires a center hole (about 5 to 8 mmφ) for loading a light source lamp and a side hole (about 2 to 3 mmφ) for passing an electrode wire. Drilling must be done. In the past, drilling was performed with a carbide drill or diamond tool.

  By the way, in the case of a small reflecting mirror, rather than press-molding each of the reflecting mirrors, a plurality of reflecting mirrors are pressed at once from a glass or crystallized glass plate-like integral molding. In some cases, a method of cutting and cutting individual reflecting mirrors may be employed. In that case, a diamond wheel or a diamond core drill was conventionally used.

  Even in the case of fly-eye lenses, especially in the case of small-sized products, instead of press-molding each fly-eye lens one by one, a glass plate-like integral molded product in which multiple fly-eye lenses are press-molded at once Therefore, a method of cutting and cutting individual fly-eye lenses may be employed. In that case, it was conventionally cut with a diamond wheel.

Japanese Patent Application Laid-Open No. 2003-225818 describes a technique for making a hole in glass with a core drill for drilling.
JP 2003-225818 A

Conventional machining using a carbide tool or diamond tool has the following two problems.
The first is that a cleaning / drying process is required. In processing using conventional cemented carbide tools and diamond tools, processing must be performed while water is constantly applied to the processing site. However, if the product is left in a state where water remains attached after the processing, water spots are generated on the product surface as the water evaporates. Water spots are a phenomenon in which mineral components dissolved in water precipitate as the water evaporates and adhere to the surface of the product as white foreign matter, which occurs on the surface of a reflector or fly-eye lens. Can be a serious quality defect. Therefore, at present, the processed product is washed with clean water containing almost no mineral components such as ion-exchanged water or pure before the adhering water evaporates, and is further dried and subjected to an inspection process. In stock. That is, since water is always used in processing using a carbide tool or a diamond tool, there has been a problem that a cleaning / drying process for preventing the occurrence of water spots is required.

  The second point is that fine scratches and cracks on the processed surface may be the starting point of breakage. The reflecting mirror is used in a high temperature environment exceeding 600 ° C. due to heat from the light source lamp, and is also exposed to severe thermal shock by turning on / off the lamp. Since the fly-eye lens is also set inside a projector, a projector, etc., it is used in a high-temperature environment of about 100 to 300 ° C. and receives a large thermal shock when turned on and off. Machining using a carbide tool or diamond tool is performed by mechanically destroying the surface of glass or crystallized glass from the microscopic viewpoint, and there are minute scratches and cracks on the processed surface. There are many. When reflectors and fly-eye lenses are used at high temperatures, or when they are subjected to a large thermal shock when they are turned on and off, these fine scratches and cracks may extend, leading to product damage and cracks. is there.

  Therefore, the inventors have tried to burn and burn glass or crystallized glass with a flame such as a burner, and perform processing such as drilling and cutting. I was faced with the inconvenience that the width of the cutting margin would become large. In addition, there is a problem that strain (stress) remains in the processed part and a slow cooling process is required.

  An object of the present invention relates to drilling and cutting of a glass or crystallized glass member such as a reflecting mirror, and is performed without using water so as to eliminate the occurrence of water spots and to improve yield and quality. At the same time, an object of the present invention is to provide a production method that can omit the washing and drying steps after processing.

  Another object of the present invention is to perforate a glass or crystallized glass member such as a reflecting mirror, or to cut a plurality of reflecting mirrors from a glass or crystallized glass plate-like integrated molding. In addition, the cutting process for cutting out multiple fly-eye lenses from a glass plate-like integrated molding suppresses the generation of minute scratches and cracks that can lead to product damage and cracks, thereby improving product reliability and safety. An object of the present invention is to provide a manufacturing method capable of improving.

In order to solve the above-mentioned problems, in the present invention, in the processing method of glass products or crystallized glass products, a step of forming a processed portion thinner than other portions in advance; and irradiating the processed portion with laser And performing a drilling or cutting process. Preferably, the thickness of the processed part is 3 mm or less, and the thermal expansion coefficient of the product material is 55 × 10 ⁻⁷ / ° C. or less.

  According to the present invention, drilling into a reflecting mirror made of glass or crystallized glass, cutting process for cutting out a plurality of reflecting mirrors from a plate-like integrated product made of glass or crystallized glass, or a glass plate A cutting process for cutting out a plurality of fly-eye lenses from a single-piece molded product can be performed without using any water. This eliminates the occurrence of water spots and contributes to the improvement of yield and quality, and at the same time, the cleaning / drying step after processing can be omitted. It does not cause fine scratches or cracks on the processed surface, and imparts reliability and safety to the product.

  Embodiments of the present invention will be described below. In the present invention, perforation processing to a reflecting mirror made of glass or crystallized glass, cutting processing for cutting out a plurality of reflecting mirrors from a glass or crystallized glass plate-like integrated molding, or glass plate-like integration A description will be given of an example of a cutting process for cutting out a plurality of fly-eye lenses from a molded product. In addition, about the drilling process to a reflective mirror, the center hole of about 5-8 mmphi and the process of a side hole of about 2-3 mmphi are demonstrated as an example.

  First, the mechanism for cutting glass or crystallized glass with a laser will be described. First, the processing part is heated locally and instantaneously by laser irradiation to bring the glass or crystallized glass into a molten state, and at the same time, molten glass (crystallized glass is also melted) with an assist gas ejected vigorously from the thin tip of the laser nozzle This is an image of removing the material to be processed while blowing away the glass melt. Thus, no water is required. Conventional processing using carbide tools and diamond tools was performed by mechanically breaking and scraping the surface of glass or crystallized glass, but laser cutting instantaneously melts the material with heat. And remove it. Therefore, the cut surface becomes a smooth surface, and basically there are no fine scratches or cracks leading to breakage or cracking of the product.

  When the thickness of the glass or crystallized glass processed part exceeds a predetermined thickness, the laser cannot penetrate the material and cannot be cut. The thinner the thickness of the processed part, the more advantageous. However, as a result of various processing tests, it has been found that it is desirable not to exceed the thickness of 3 mm. Furthermore, when designing a mold for press-molding a product, it is preferable to mold only the processed portion to a thickness of about 2 mm or less. In addition, as a method of thin-working the processing site, it is possible to employ post-molding cutting or the like in addition to press molding.

  When trying to forcibly cut a material with a thickness of more than 3 mm by increasing the laser output or increasing the irradiation time, the peripheral part of the processed part will also be heated, causing strain (stress). Residues, cracks due to thermal shock, and icicle-like unmelted residue called dross may be adversely affected.

As described above, the laser cutting is performed by instantaneous melting of the material and blow-off of the melt by the assist gas, so that the material is subjected to intense rapid heating / cooling locally. In this case, if the glass or crystallized glass as the material has a large thermal expansion coefficient, cracks are generated due to rapid expansion / contraction. Even if the coefficient of thermal expansion is large, cracks are less likely to occur if the material is extremely thin. However, when a realistically press-molded glass or crystallized glass reflecting mirror or fly-eye lens is considered as the object to be processed, the thickness of the processed part is about 1 to 3 mm. When cutting this thickness, the thermal expansion coefficient of glass or crystallized glass is desirably 55 × 10 ⁻⁷ / ° C. or less. It was practically difficult to cut a glass or crystallized glass reflecting mirror or fly-eye lens having a thermal expansion coefficient exceeding 55 × 10 ⁻⁷ / ° C. without causing cracks by a laser.

More specifically, the processing is preferably performed under the following conditions.
When processing a material having a thermal expansion coefficient of 45 to 55 × 10 ⁻⁷ / ° C., the thickness is 1 mm or less.
When processing a material having a thermal expansion coefficient of 35 to 45 × 10 ⁻⁷ / ° C., the thickness is 2 mm or less.
When processing a material having a thermal expansion coefficient of 35 × 10 ⁻⁷ / ° C. or less, the thickness is 3 mm or less.
When processing a material having a thickness of 1 mm or less, the thermal expansion coefficient is 55 × 10 ⁻⁷ / ° C. or less.
In the case of processing a material having a thickness of 1 to 2 mm, the thermal expansion coefficient is 45 × 10 ⁻⁷ / ° C. or less.
In the case of processing a material having a thickness of 2 to 3 mm, the thermal expansion coefficient is 35 × 10 ⁻⁷ / ° C. or less.

  The type of laser used for processing is preferably a carbon dioxide gas laser that can produce a relatively large output. However, if the thickness of the processed part of glass or crystallized glass is thin, a YAG laser or excimer laser can be used. It is. As equipment, a commercially available carbon dioxide laser device combined with an XY stage can be adopted. Conversely, it is also possible to employ a method in which the workpiece is fixed and the laser nozzle is scanned.

  The timing of the laser processing may be hot, that is, immediately after the reflector or fly-eye lens is press-molded (the glass is hot at around 400 ° C.). Further, it may be in a state of around 100 ° C. immediately after the product exits the slow cooling furnace following the press. Furthermore, it is possible even at room temperature when the product is completely cooled. In the case of crystallized glass, it may be in the state of glass before heat treatment for crystallization or in the state of crystallized glass after heat treatment and crystallization. In other words, laser cutting can be performed at any timing during the manufacturing process.

  Laser irradiation may be performed from either side of the product. Of course, the distance between the tip of the laser nozzle and the surface of the work material is set to about 1 mm. That is, it is important that the laser nozzle can be physically close to the material surface so that the focal point of the laser can be close to the material surface.

  It is also possible to lightly chamfer the edge (corner) of the processed part with a dry grinding / polishing tool that does not use water after cutting with a laser.

  Next, this invention is demonstrated based on an Example. In any of the examples, a commercially available carbon dioxide laser with a maximum output of 500 W was used as the laser. In any of the examples, the processing was performed by fixing the laser nozzle, placing the workpiece on the XY stage, and scanning according to the program. When processing the same part of the same product continuously, it is desirable to use a jig that can easily fix the workpiece to the same position on the XY stage in the same direction. Furthermore, it goes without saying that cost reduction can be achieved by automating the product conveyance process including laser irradiation.

(Example 1)
The target is a crystallized glass reflecting mirror 2 having a thermal expansion coefficient of 15 × 10 ⁻⁷ / ° C. in a room temperature state. In this reflecting mirror 2, a center hole of 8 mmφ and a side hole of 3 mmφ were drilled with a laser. The average thickness of the reflector is 4.5 mm, but the center hole portion and the side hole portion (processed portion) are preliminarily pressed to a thickness of about 2 mm.

  1 and 2 show a state in which a center hole is formed in the reflecting mirror 2. Laser irradiation is possible both in the direction from the inner surface to the outer side and in the direction from the outer side to the inner surface. In the figure, reference numeral 1 denotes a laser nozzle; reference numeral 3 denotes a jig for supporting the reflecting mirror 2; and reference numeral 4 denotes a center hole forming portion (processing portion). The center hole could be drilled in about 6 seconds.

  3 and 4 show a state in which side holes are formed in the reflecting mirror 2. In particular, when the side hole is drilled, it is preferable to use the jig 3. 3 and 4 are views in which side holes are formed by irradiating laser from the opposite surface. As shown in FIG. 4, when irradiating a laser toward the inner side of the reflecting mirror 2, the shielding plate 6 is used so as not to damage the inner surface facing the penetrated laser. Side holes could be drilled in about 3 seconds. In the figure, reference numeral 5 denotes a side hole forming portion (processed portion).

  There was no abnormality in the appearance of the reflector that had been drilled. It also passed the quality standard thermal shock test. Furthermore, no abnormality was observed in the mounting test. In addition, we tried to drill 8mmφ and 3mmφ in the normal thick part (4.5mm thick part) other than the center hole processing part 4 and side hole processing part 5, but the laser did not penetrate and the drilling Processing was not possible.

(Example 2)
A description will be given of an example in which each reflecting mirror 12 is cut by a laser from a glass plate-like integrally molded product 8 in which two (plural) small reflecting mirrors 12 are press-molded at a time. The plate-like integral molded product 8 was collected at about 100 ° C. on the conveyor at the outlet of the continuous slow cooling furnace. FIG. 5 is a schematic diagram showing the state of processing. The coefficient of thermal expansion of glass is 40 × 10 ⁻⁷ / ° C. A V-shaped groove 7 is formed around each reflecting mirror, and the processed part is pressed so that the thickness thereof is about 1 mm. One reflector could be cut out in about 30 seconds. The peripheral length, that is, the cutting length was about 150 mm.

No abnormalities in appearance were observed in the cut-out reflecting mirror 12. It also passed the quality standard thermal shock test. Furthermore, no abnormality was observed in the mounting test. In addition, when laser processing was similarly performed using a glass plate-like integral molded product having a thermal expansion coefficient of 65 × 10 ⁻⁷ / ° C., although cutting and cutting were successful, Many fine cracks were observed with the naked eye.

(Example 3)
Next, an example will be described in which each fly eye lens 9 is cut by laser cutting from a glass plate-like integrally molded product 18 in which six (plural) fly eye lenses 9 are press-molded at a time. . The plate-like integral molded product 18 was collected immediately after press molding, and the glass was hot at around 400 ° C. FIG. 6 shows a schematic view of the processing. The coefficient of thermal expansion of glass is 40 × 10 ⁻⁷ / ° C. A V-shaped groove 7 is formed around each fly-eye lens 9 and is pressed so that the thickness of the processed portion 7 is about 2 mm. One fly-eye lens could be cut out in about 40 seconds. The peripheral length, that is, the cutting length was about 160 mm. Thereafter, the individual fly-eye lenses 9 cut out were passed through a continuous slow cooling furnace to remove the strain.

No abnormal appearance was observed in the fly-eye lens 9 after slow cooling. Furthermore, no abnormality was observed in the mounting test. In addition, when laser processing was carried out in the same manner using a glass plate-like integral molded product having a thermal expansion coefficient of 65 × 10 ⁻⁷ / ° C., cutting and cutting were successful, but at the continuous slow cooling furnace entrance. Many fine cracks were observed with the naked eye on the cut surface of the fly-eye lens. Most of them were damaged by extension of cracks in a continuous annealing furnace, and no good products were obtained.

  As described above, drilling process in the reflecting mirror 2 made of crystallized glass, cutting process for cutting out the plurality of reflecting mirrors 12 from the glass plate-like integrated molded article 8, or a plurality of pieces from the glass plate-like integrated molded article 18 are performed. The cutting process for cutting out the fly-eye lens 9 has been described based on the examples. However, the present invention is not limited to the above-described embodiments, and a hole for air cooling is formed in the flange portion of the reflecting mirror, a fixing hole is formed in the edge portion of the reflecting mirror, or a fly-eye lens. The present invention can be applied to various processes such as making a fixing hole in the edge portion of the metal plate. Further, in addition to a reflecting mirror and a fly-eye lens, the present invention can be applied to a process of individually cutting a normal optical lens, a minute aspheric lens, and other optical components from a glass plate material integrated molding.

It is a cross-sectional schematic diagram which shows a mode that the center hole is drilled by the reflecting mirror using the method by 1st Example of this invention. It is a cross-sectional schematic diagram which shows a mode that the center hole is drilled by the reflecting mirror with the laser from the surface opposite to FIG. It is a cross-sectional schematic diagram which shows a mode that the side hole is drilled in a reflecting mirror with a laser using the method by 1st Example of this invention. It is a cross-sectional schematic diagram which shows a mode that the side hole is drilled by the laser from the surface opposite to FIG. Section showing a state in which individual reflectors are cut and cut out with a laser from a plate-like integrated molded product in which a plurality of small reflectors are press-molded at once using the method according to the second embodiment of the present invention. It is a schematic diagram. FIG. 4 shows a state where individual fly-eye lenses are cut by laser cutting using a method according to a third embodiment of the present invention, from a plate-like integrated product in which a plurality of fly-eye lenses are press-molded at once. It is a cross-sectional schematic diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser nozzle 2,12 Reflector 3 Fixing jig | tool 4 Center hole processing site | part 5 Side hole processing site | part 6 Shielding board 7 V-shaped groove | channel 8, 18 Plate-shaped integral molding 9 Fly eye lens

Claims (22)

In the processing method of glass products or crystallized glass products,
A step of forming a processed portion thinner than other portions in advance;
And a step of performing drilling or cutting by irradiating a laser to the processing site.   The method according to claim 1, wherein a thickness of the processed portion is 3 mm or less. The method according to claim 1, wherein the product material has a thermal expansion coefficient of 55 × 10 ⁻⁷ / ° C. or less. 2. The method according to claim 1, wherein the thickness of the processed part is 3 mm or less, and the coefficient of thermal expansion of the product material is 55 × 10 ⁻⁷ / ° C. or less.   The method according to claim 1, 2, 3, or 4, wherein the laser is a carbon dioxide laser.   A glass product or a crystallized glass product manufactured using the processing method according to claim 1, 2, 3, 4 or 5. In the processing method of the reflector made of glass or crystallized glass,
A step of forming a processed portion thinner than other portions in advance;
And a step of drilling by irradiating the processing site with a laser.   The processing method according to claim 7, wherein a thickness of the processing portion is 3 mm or less. The processing method according to claim 7, wherein the member has a thermal expansion coefficient of 55 × 10 ⁻⁷ / ° C. or less. The processing method according to claim 7, wherein a thickness of the processing part is 3 mm or less, and a thermal expansion coefficient of the member is 55 × 10 ⁻⁷ / ° C. or less.   The processing method according to claim 7, wherein the laser is a carbon dioxide laser.   A reflecting mirror manufactured using the processing method according to claim 7, 8, 9, 10, or 11. In a manufacturing method of a reflecting mirror including a step of cutting individual reflecting mirrors from a glass or crystallized glass plate integrally formed with a plurality of reflecting mirrors,
A step of forming the cut portion of the plate material thinly in advance at the stage of integral molding compared to other portions;
A method of manufacturing a glass or crystallized glass reflecting mirror, comprising a step of performing a cutting process by irradiating the cutting part with a laser.   The manufacturing method according to claim 13, wherein a thickness of the cut portion is 3 mm or less. The manufacturing method according to claim 13, wherein a thermal expansion coefficient of the member is 55 × 10 ⁻⁷ / ° C. or less. The manufacturing method according to claim 13, wherein a thickness of the cut portion is 3 mm or less, and a thermal expansion coefficient of the member is 55 × 10 ⁻⁷ / ° C. or less.   The manufacturing method according to claim 13, 14, 15 or 16, wherein the laser is a carbon dioxide gas laser. In a fly eye lens manufacturing method including a step of cutting individual fly eye lenses from a glass or crystallized glass plate in which a plurality of fly eye lenses are integrally formed,
A step of forming the cut portion of the plate material thinly in advance at the stage of integral molding compared to other portions;
A method for producing a fly-eye lens made of glass or crystallized glass, comprising a step of performing a cutting process by irradiating a laser to the cut portion.   The manufacturing method according to claim 18, wherein a thickness of the cut portion is 3 mm or less. The manufacturing method according to claim 18, wherein the member has a thermal expansion coefficient of 55 × 10 ⁻⁷ / ° C. or less. The manufacturing method according to claim 18, wherein a thickness of the cut portion is 3 mm or less and a thermal expansion coefficient of the member is 55 × 10 ⁻⁷ / ° C. or less.   The manufacturing method according to claim 18, wherein the laser is a carbon dioxide laser.

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