JP2009000704A - Marking on surface and inside of transparent board using laser beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for carrying out the marking on the surface and the inside of a transparent board by the same apparatus, and further to provide an exposure device to be used for carrying out the marking, and a novel marked transparent board which has the marking on the front surface and the inside thereof and has not been seen in the market until now. <P>SOLUTION: There are provided a laser beam source for radiating a laser beam, and a laser beam scanner which scans the laser beam radiated from the laser beam source via an fθ lens 1 to a required position by deflecting the laser beam using a galvano-meter composed of a galvano-device 14 having a galvano-mirror 15 and a galvano-device 16 having a galvano-mirror 17. Further a transparent parallel flat plate 3 is arranged between the fθ lens 1 and a workpiece 2 so as to be inserted-in/receded-from there. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transparent plate, and more particularly to a method for marking the surface and the inside of a transparent glass plate or transparent plastic plate, an exposure apparatus using a laser beam used in the method, and a marked transparent plate. .

  Conventionally, an exposure apparatus using a laser beam that exposes a 2D code or the like to a resist on the surface of a glass substrate (workpiece) and an exposure apparatus that performs marking in the form of so-called inner marking inside a glass substrate have existed.

  However, there has been no exposure apparatus for marking the glass surface and inside with the same apparatus. This is because it was considered impossible to carry out with the same device because the focal position was different between the surface and the inside.

Therefore, there was no glass substrate with markings on the surface and inside.
JP-A-9-103893 Japanese Patent No. 3029045

  Accordingly, the first object of the present invention is to provide a method for marking the surface and the inside of a transparent plate such as a transparent glass plate or a transparent plastic plate with the same apparatus, and an exposure apparatus used for the method. The aim is to use the exposure apparatus to provide a new type of marking transparency that has been marked on the surface and inside that was not previously seen in the market.

  The second object is to narrow the margin by marking data such as numbers, letters, alphabets, symbols, figures, marks, and 2D codes on the surface and inside of the glass substrate (work) with the same exposure apparatus, for example. Double the amount of data can be marked easily and economically, and workpieces marked on the surface and inside can be made safe even if one data disappears due to an accident, data safety It is to provide a work having a function of preventing forgery by ensuring that the data marked inside is not detected by the device that detects the data marked on the surface.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is directed to a laser light source that emits a laser beam and a laser beam emitted from the laser light source. Is marked with an exposure apparatus having a laser beam scanner that scans to a desired position via an fθ lens. The marking inside the transparent plate is transparent between the fθ lens of the exposure device and the transparent plate. It is a marking method on the surface and inside of a transparent plate, wherein marking is performed by inserting a plane parallel plate.

  The invention according to claim 2 is the marking method for the surface and inside of the transparent plate according to claim 1, wherein the laser power is variable.

According to a third aspect of the present invention, in the first or second aspect of the invention, the marking on the inside of the transparent plate uses a laser whose pulse width is shorter than 10 ⁻⁸ seconds. It is a marking method for the inside.

  The invention according to claim 4 includes a laser light source that emits laser light, and a laser beam scanner that deflects the laser light emitted from the laser light source using a galvanometer and scans the laser light to a desired position via an fθ lens. In addition, the marking apparatus is characterized in that a transparent parallel plane plate that can be inserted and retracted is disposed between the fθ lens and the workpiece.

  A fifth aspect of the present invention is the marking device according to the fourth aspect, wherein the laser power is variable.

A sixth aspect of the present invention is the marking apparatus according to the fourth or fifth aspect, wherein a laser having a pulse width shorter than 10 ⁻⁸ seconds is used.

  The invention according to claim 7 is the marking transparent plate made of transparent glass or transparent plastic, wherein the same or different numbers, letters, alphabets, symbols, figures, marks, marks, 2D codes, etc. are marked on the surface and inside. It is.

The invention according to claim 8 uses a laser that marks the same or different numbers, letters, alphabets, symbols, figures, marks, marks, 2D codes, etc. on the surface and inside and has a pulse width shorter than 10 ⁻⁸ seconds. A marking transparent plate made of transparent glass or transparent plastic, characterized in that part or all of the internally marked data cannot be seen with the naked eye.

  FIGS. 1 and 2 are schematic views showing the configuration and the function and effect of the main part of the invention described in claim 1. FIG. 1 shows, for example, when marking on the surface of the glass substrate 2, and FIG. A state in which the plane parallel plate 3 is arranged between the fθ lens 1 ′ and the glass substrate 2 to mark the inside of the glass substrate 2 is shown.

  1 and 2 show only the main part different from the conventional apparatus of the laser marking exposure apparatus according to the present invention. The laser light source for emitting laser light and the laser light emitted from the laser light source are shown. The laser beam scanner that deflects the light beam with a galvanometer and scans it to the desired position via the fθ lens 1 ′ is the same as that of a known device, and is therefore omitted.

  Therefore, in the state shown in FIG. 1, the surface of the glass substrate 2 can be marked as in the conventional apparatus.

  FIG. 2 shows a case where a transparent plane plate 3 made of glass or plastic is inserted between the fθ lens 1 ′ and the glass substrate 2. When the plane parallel plate 3 is thus inserted, the focal position of the laser beam L is parallel. Since it moves downward by the amount of the flat plate 3, it is possible to mark the inside of the glass substrate 2 by selecting the thickness and refractive index of the parallel flat plate 3. Of course, when marking on a resist-coated glass substrate, the laser power is lowered.

  The case shown in FIG. 2 is a case where there is one parallel plane plate 3, but a plurality of sheets having different refractive indexes or thicknesses are provided, and a plurality of parallel plane plates are appropriately selected to obtain a glass substrate. The marking position (distance) from the surface of 2 can be selected.

  Here, the position where the plane-parallel plate is arranged is not limited. However, the position closer to the fθ lens where the moving range of the laser light is narrower requires a smaller size of the plane-parallel plate, so the position is closer to the fθ lens. It is preferable to provide in.

  The laser used for the marking is an Nd-YAG laser having a wavelength of 1064 nm, a second harmonic of 532 nm, a third harmonic of 355 nm, or a fourth harmonic of 266 nm, a 193 nm excimer laser (ArF), or 249 nm. An excimer laser (KrF) wavelength laser is used. The absorptance of laser light into glass greatly depends on the wavelength λ, and particularly ultraviolet light is absorbed more strongly. That is, the shorter the wavelength, the sharper marking becomes possible.

  Therefore, when sharp marking is performed, the Nd-YAG laser fourth harmonic (266 nm), 193 nm excimer laser (ArF), and 249 nm excimer laser (KrF) are effective.

The sharpness of the processed surface varies depending on the width of the pulse, and it is said to be 10 ⁻¹⁰ seconds to 10 ⁻¹² seconds, which is called ps (picoseconds) shorter than 10 ⁻⁷ seconds to 10 ⁻⁹ seconds called ns (nanoseconds). The machined interface is more beautiful when using the laser.

When processing a plastic workpiece, a CO ₂ laser with a wavelength of 10.6 μm is best absorbed. Therefore, when marking a plastic workpiece, a good result can be obtained by using a CO ₂ laser.

  In the case of the present invention, since the plastic needs to be transparent, an amorphous plastic such as acrylic or polycarbonate is used as the workpiece.

Therefore, by marking a small code that is not visible using a short-wavelength laser of the third harmonic or the fourth harmonic with a pulse of 10 ⁻⁸ seconds or less, it has only a dedicated reader, Since a counterfeiter who does not know the means for writing invisible markings cannot imitate a genuine marking transparent plate, it can also be used as a countermeasure against counterfeits.

  In order to use a small code, the spot diameter W using a laser is known as W = 1.27λf / D as is well known. Therefore, in order to obtain a small spot diameter, a short wavelength, a short focal length, and a large diameter are used. It can be seen that the incident beam is necessary. Here, λ is a wavelength, f is a focal length, and D is an incident beam diameter.

  Since f and D can be selected by design, the wavelength of 355 nm, which is the third harmonic of the Nd-YAG laser, or 266 nm, which is the fourth harmonic, is used to reduce λ.

  Of course, it is possible to create a large code with a large spot diameter by stacking spots horizontally without being bound by a small code, and to select f and D by design from the beginning so that the spot diameter is large. Of course.

Also, long and short laser pulses with high peak power and short pulse duration cause the material to quickly ionize and evaporate before thermal effects such as thermal diffusion occur, so the laser pulse can store energy in the material for a short period of time. In addition, since the energy in the irradiated region of the target is not propagated to the surroundings and lost, heating and ionization are localized only in the irradiated region, so that cracks occur in the target portion inside the glass substrate. Is suppressed. Therefore, it is possible to obtain a small spot of 30 μm or less without generating cracks using a laser having a pulse width of 10 ⁻⁸ seconds or less.

  According to the first aspect of the present invention, it is possible to provide an exposure apparatus capable of marking the surface and the inside of a transparent plate (work) with a single exposure apparatus, and also for marking the inside of the work. When changing the focal length, it is possible not only to perform an accurate and high-quality marking, but also to provide a focal length changing mechanism easily and inexpensively compared to a zoom lens or the like. it can.

  Further, according to the invention described in claim 2, it is possible to cope with the case of marking a resist-coated glass substrate that requires a small laser power.

  Further, according to the invention described in claim 3, it is possible to perform marking with a watermark effect to be put on a bill or the like for preventing forgery.

  Moreover, according to the invention of Claim 4, the exposure apparatus which can perform marking on the surface and inside of a workpiece | work can be provided.

  According to the fifth aspect of the present invention, it is possible to provide an exposure apparatus that can cope with marking of a resist-coated glass substrate that requires a small laser power.

  According to the sixth aspect of the present invention, it is possible to provide an exposure apparatus capable of performing marking with a watermark effect to be put on a bill or the like for preventing forgery.

  Further, according to the invention of claim 7, it is possible to provide a transparent plate having twice the amount of marked information as in the past, and when the same data is marked on the surface and inside, one of the data is caused by an accident. It is possible to provide a transparent plate that does not interfere even if it disappears.

  Further, according to the invention described in claim 8, it is possible to provide a transparent plate on which hidden information required for forgery prevention or required by an issuer is marked.

  FIG. 3 is a perspective view showing a schematic configuration of the embodiment, in which laser light emitted from a laser light source that emits laser light (not shown) is incident on a galvano mirror 15 attached to the galvano 14, and the reflected laser light is reflected. The glass substrate 2 (workpiece) is irradiated through the fθ lens 1 reflected downward by the galvano mirror 17 attached to the galvano 16 and the transparent parallel flat plate 3 to mark the inner surface.

  When marking the surface of the workpiece 2, the transparent parallel flat plate 3 is moved and retracted to the side.

  FIGS. 4 and 5 show an embodiment in which one parallel plane plate 3 is inserted and retracted between the fθ lens 1 and the glass substrate 2, and the transparent plane plane plate 3 is attached by the plane parallel plate holder 9. The holder 4 is rotatably provided on the base 5 and the shaft 10 of the holder 4 is rotated by a stepping motor 8 via gears 6 and 7. Reference numeral 11 denotes a shaft of a stepping motor 8 to which the gear 7 is attached.

  The plane parallel plate 3 is made of glass or plastic having a thickness or a refractive index such that the laser beam focuses on the inner surface of the workpiece 2 when the plane parallel plate 3 is inserted into the field of view of the fθ lens.

  In the inner marking method and apparatus disclosed in the above-mentioned Japanese Patent No. 3029045, since marking on the inner surface of a vertically standing bottle is assumed, as the focus moving means in the height direction of the marking beam A stepping motor is used, and the focal length is adjusted with a zoom lens.

  However, the method of changing the focal length with the zoom lens has a problem that the light condensing performance is lowered and the control device is expensive.

  However, according to the present invention, the inner surface of the glass substrate can be marked by simple positioning of the plane parallel plate, and the surface of the glass substrate can also be marked. It provides a very effective method for countermeasures.

  Although the said Example is a case where the one plane parallel plate 3 is used, when using the plane parallel plate from which thickness and refractive index differ, a several plane parallel plate is provided and one of them is provided. A structure that is selected and rotated, a structure that slides parallel plane plates arranged in a line, such as a film feeding device of a film projector, or a structure that is a turret filter.

  If these parallel plane plate changing apparatuses are used, the surface and the inner surface of the glass substrate 2 can be marked with a relatively simple mechanism and control, which is very useful.

Schematic diagram showing the main configuration of the present invention when marking on the workpiece surface Schematic diagram showing the main configuration of the present invention when marking inside the workpiece The perspective view which shows the principal part structure of this invention Example Partially cutaway side view of moving device of parallel plane plate in embodiment of the present invention Plan view of FIG.

Explanation of symbols

1,1 'fθ lens
2 Glass substrate
3 Parallel plane plate 4 Holder 5 Base 6, 7 Gear
8 Stepping motor 9 Parallel plane plate presser 10, 11 Shaft 12 Stand-by position 13 Insertion position 14, 16 Galvano 15, 17 Galvano mirror

Claims (8)

The marking on the surface of the transparent plate is an exposure provided with a laser light source that emits laser light and a laser beam scanner that deflects the laser light emitted from the laser light source using a galvanometer and scans it to a desired position via an fθ lens. Marking by means of an apparatus, and marking inside the transparent plate is performed by inserting a transparent plane parallel plate between the fθ lens and the transparent plate of the exposure apparatus, and marking the surface and inside of the transparent plate . 2. The marking method for the surface and inside of a transparent plate according to claim 1, wherein the laser power is variable. The marking method for the surface and the inside of a transparent plate according to claim 1 or 2, wherein a laser having a pulse width shorter than ^10-8 seconds is used for marking the inside of the transparent plate. A laser light source that emits laser light; a laser beam scanner that deflects the laser light emitted from the laser light source using a galvanometer and scans the laser light to a desired position via an fθ lens; and between the fθ lens and the workpiece A marking device characterized in that a transparent parallel plane plate which can be inserted and retracted is arranged on the surface. The marking device according to claim 4, wherein the laser power is variable. ^6. A marking apparatus according to claim 4, wherein a laser having a pulse width shorter than 10 ⁻⁸ seconds is used. A marking transparent plate made of transparent glass or transparent plastic, characterized in that the same or different numbers, letters, alphabets, symbols, figures, marks, 2D codes, etc. are marked on the surface and inside. Part of the data marked internally with the same or different numbers, letters, alphabets, symbols, figures, marks, marks, 2D codes, etc., marked on the surface and inside using a laser with a pulse width shorter than ^10-8 seconds Alternatively, a marking transparent plate made of transparent glass or transparent plastic, characterized in that the whole cannot be seen with the naked eye.

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