JP2004043981A - Apparatus for bleaching treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for a bleaching treatment designed to carry out the bleaching treatment at a high energy density and perform the bleaching treatment with high energy efficiency at a high speed and low cost by irradiation with a short-period pulsated laser beam. <P>SOLUTION: The apparatus for the bleaching treatment is designed to perform pulse irradiation of a cloth 200 impregnated with a chemical fluid containing an oxidizing agent or a reducing agent with a laser beam at 350-450 nm wavelength by using an irradiation head 500 loaded with a fiber array light source in which a high-output and high-brightness multiplexing laser beam light source is arrayed. Thereby, the high energy density can be obtained on the surface of the cloth 200. The bleaching reaction can be promoted to afford high bleaching effects by activating at least either one of the chemical fluid and a coloring component. Furthermore, the irradiation with the short-period pulsated laser beam can be carried out by composing the multiplexing laser beam light source of a semiconductor laser. The bleaching treatment can be performed with the high energy efficiency at a high speed and low cost. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bleaching apparatus, and more particularly to a bleaching apparatus that performs bleaching by irradiating a cloth impregnated with a chemical solution containing an oxidizing agent or a reducing agent with laser light.
[0002]
[Prior art]
In the dyeing process of a textile product, before performing the dyeing process, a bleaching process is performed in which a coloring substance contained in the fiber is decomposed and removed by oxidation or reduction process. The colored substance contains conjugated double bonds involved in color development in its structure, but the conjugated system of the colored substance is broken by the oxidation or reduction treatment, and as a result, the fiber is bleached. As the oxidizing bleaching agent, chlorine-based bleaching agents such as sodium hypochlorite and hydrogen peroxide are used, and as the reducing bleaching agent, hydrosulfite and the like are used.
[0003]
Conventionally, the above bleaching treatment is generally performed by boiling a fiber product in an aqueous solution containing a high concentration bleaching agent for a long time, but water having a large heat capacity must be heated to near the boiling point, There was a problem that the energy efficiency was poor and the fiber was brittle or hardened due to the interaction between heat and chemicals.
[0004]
In recent years, research on bleaching technology that does not use a chlorine bleach that has a large environmental impact has been actively conducted. For example, Japanese Patent Laid-Open No. 11-43861 discloses a technique for performing bleaching by irradiating a cotton cloth impregnated with an aqueous sodium borohydride solution with an ultraviolet laser at room temperature. Sodium borohydride used as a bleaching agent has a weak reducing power, but a colored substance is activated by laser irradiation and easily reacts with the bleaching agent. According to this technique, not only the chlorine bleaching agent is not used, but also bleaching can be performed at a low temperature, and the processing time is shortened. Further, since the bleaching process can be performed at a low temperature, fiber damage is also reduced.
[0005]
This bleaching method requires a laser device with a high energy density and uses an excimer laser that can obtain a high output in the ultraviolet region. In addition, since a semiconductor laser that oscillates at a wavelength in the ultraviolet region generally has a small output, when a semiconductor laser is used, a plurality of semiconductor lasers are integrated and used.
[0006]
[Problems to be solved by the invention]
However, the excimer laser has a low energy efficiency of only 3%, and a bleaching method using the excimer laser consumes a large amount of energy and cannot be said to be an environmentally friendly bleaching method. In addition, the excimer laser has a low pulse drive repetition frequency of 300 Hz, and has low productivity. Furthermore, the life of the laser tube and laser gas is 1 × 10 ⁷ There are also problems such as short shots, high maintenance costs, large equipment, high-intensity laser light, and difficulty in pulsing.
[0007]
Conventionally, a semiconductor laser that oscillates at a wavelength in the ultraviolet region has not been put into practical use, and Japanese Patent Laid-Open No. 11-43861 does not describe a specific configuration of the semiconductor laser. In addition, short-wavelength semiconductor lasers are difficult to manufacture with a high yield. However, Japanese Patent Application Laid-Open No. 11-43861 integrates a plurality of semiconductor lasers that oscillate at wavelengths in the ultraviolet region, and is 10,000 mJ / cm. ² No specific configuration for realizing the light density is described, and it has been difficult to obtain a high-output light source using a semiconductor laser that actually oscillates at a wavelength in the ultraviolet region.
[0008]
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a bleaching apparatus capable of performing a bleaching process at a high energy density by irradiation with a laser beam having a short pulse. There is. Another object of the present invention is to provide a bleaching apparatus that is high in energy efficiency and capable of performing bleaching at high speed and low cost.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a bleaching apparatus of the present invention comprises a chemical solution impregnation means for impregnating a fiber before dyeing with a chemical solution containing an oxidizing agent or a reducing agent, a plurality of semiconductor lasers, a single optical fiber, and the above-mentioned A laser beam emitted from each of a plurality of semiconductor lasers is condensed, and a combined laser light source having a condensing optical system for coupling the condensed beam to the incident end of the optical fiber is provided, and the chemical solution is impregnated. And a laser irradiation means for irradiating the cloth with a laser beam having a wavelength of 200 nm to 450 nm.
[0010]
In the bleaching apparatus of the present invention, the chemical solution containing the oxidizing agent or the reducing agent is impregnated into the fibers before dyeing by the chemical solution impregnation means. The cloth impregnated with the chemical solution is pulse-irradiated with laser light having a wavelength of 200 nm to 450 nm from the laser irradiation means.
[0011]
The combined laser light source condenses laser beams emitted from each of a plurality of semiconductor lasers, a single optical fiber, and the plurality of semiconductor lasers, and couples the condensed beam to an incident end of the optical fiber. An optical optical system is provided. Since this combined laser light source combines a plurality of laser beams using an optical fiber, it has high output and high brightness. Since the laser irradiation means is provided with this high-power and high-intensity combined laser light source, the bleaching apparatus of the present invention can easily obtain a high energy density necessary for the bleaching process. In addition, since the combined laser light source is configured using a semiconductor laser that can be continuously driven and has excellent output stability, it can irradiate a laser beam with a short pulse, has high energy efficiency, and high speed. The bleaching process can be performed, and the maintenance is easy and the cost is low as compared with an apparatus using an excimer laser.
[0012]
In the above bleach processing apparatus, the wavelength of the laser light irradiated by the laser irradiation means is 350 nm from which a high-power gallium nitride (GaN) semiconductor laser can be obtained from the viewpoint of increasing the speed by accelerating the bleaching process. A range of ˜450 nm is preferred. In particular, a wavelength range of 400 nm to 415 nm, which is the easiest to increase the output with a GaN-based semiconductor laser, is preferable. Further, from the viewpoint of reducing fiber damage and improving bleaching performance, the wavelength is preferably 200 nm to 350 nm. Furthermore, from the viewpoint of reducing the cost of the apparatus without using a special material optical system and performing high-speed processing, a wavelength longer than 400 nm is preferable.
[0013]
Further, since the GaN-based semiconductor laser is a covalent bond, the dislocation mobility is much smaller than that of the GaAs-based and AlGaInP-based materials, and the thermal conductivity coefficient is also much larger than that of the GaAs-based or AlGaInP-based materials. (Catatropic Optical Damage) level. For this reason, high output can be achieved even in the case of pulse driving. As a result, it is possible to obtain a high output of several hundred mW to several tens of W in peak power by shortening the pulse. As a result, the duty can be reduced to about 0.1% to 10%, a high energy density can be obtained, and fiber damage due to heat can be reduced.
[0014]
The combined laser light source collects a laser beam emitted from each of a plurality of light emitting points of a semiconductor laser having a plurality of light emitting points, a single optical fiber, and the semiconductor laser having the plurality of light emitting points. A condensing optical system that emits light and couples the condensed beam to the incident end of the optical fiber may be provided. For example, a multicavity laser can be used as a semiconductor laser having a plurality of light emitting points.
[0015]
Further, as the optical fiber of the combined laser light source, it is preferable to use an optical fiber having a uniform core diameter and a smaller cladding diameter at the emitting end than the cladding diameter at the incident end. By reducing the cladding diameter at the emission end, the brightness of the light source can be increased. The cladding diameter at the exit end of the optical fiber is preferably smaller than 125 μm, more preferably 80 μm or less, and particularly preferably 60 μm or less from the viewpoint of reducing the diameter of the light emitting point. An optical fiber having a uniform core diameter and a cladding diameter at the output end smaller than the cladding diameter at the input end can be configured by, for example, combining a plurality of optical fibers having the same core diameter but different cladding diameters. Further, by configuring the plurality of optical fibers so as to be detachable with connectors, the replacement becomes easy when the light source module is partially damaged.
[0016]
The laser irradiation unit may include a plurality of combined laser light sources. For example, it may be configured as a fiber array light source in which a plurality of light emission points (output ends of optical fibers) of a combined laser light source are arranged in an array or a fiber bundle light source in which light emission points of a combined laser light source are bundled. In the fiber array light source and the fiber bundle light source, the light source is configured by bundling a plurality of optical fibers, so that it is possible to further increase the output. As a result, a high-intensity light source can be obtained at a low cost, and laser bleaching can be performed at high speed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the bleaching apparatus of the present invention will be described in detail with reference to the drawings.
[Configuration of bleaching equipment]
As shown in FIG. 1, the bleaching apparatus according to the embodiment of the present invention includes a plurality of transport rollers 202 that transport a long cloth 200 along a predetermined transport path.
The bleaching apparatus includes a chemical tank 206 in which a chemical liquid 204 containing an oxidizing agent or a reducing agent is stored. A laser irradiation unit 208 is provided on the downstream side of the chemical tank 206 in the transport direction. In the laser irradiation unit 208, as shown in FIG. 2, an irradiation head 500 for irradiating the cloth 200 with a pulse of laser light is disposed above the cloth 200 placed in the conveyance path.
[0018]
As shown in FIGS. 3A and 3B, the irradiation head 500 is a fiber array light source in which a large number (for example, 1000) of optical fibers 30 are arranged in a line along a direction orthogonal to the sub-scanning direction. 506 and a cylindrical lens 510 that focuses laser light emitted from the fiber array light source 506 only in a direction orthogonal to the arrangement direction of the emission ends of the optical fiber 30 and forms an image on the surface (scanning surface) 56 of the cloth 200. It consists of and. In FIG. 3, the module portion of the fiber array light source 506 to which the incident end of the optical fiber 30 is coupled is not shown.
[0019]
The cylindrical lens 510 has a curvature in a predetermined direction and is long in a direction orthogonal to the predetermined direction, and a longitudinal direction (a direction orthogonal to the predetermined direction) is parallel to the arrangement direction of the emission ends of the optical fiber 30. It is arranged to be. In addition to the cylindrical lens 510, the uniform illumination optical system using the fly-eye lens system, and the arrangement direction of the laser emitting end, the portion near the optical axis of the lens spreads the light beam and the portion away from the optical axis is the light beam. And a light amount distribution correcting optical system having a function of allowing light to pass through in a direction orthogonal to the arrangement direction may be used.
[0020]
As shown in FIG. 4, the fiber array light source 506 includes a large number of laser modules 64, and one end of the multimode optical fiber 30 is coupled to each laser module 64. The other end of the multimode optical fiber 30 is drawn out of the package 40, and the emission end (light emitting point) of the multimode optical fiber 30 is arranged along the main scanning direction orthogonal to the sub-scanning direction. 68 is configured.
[0021]
The laser module 64 is configured by a combined laser light source (fiber light source) shown in FIG. This combined laser light source includes a plurality of (for example, seven) chip-like lateral multimode or single mode GaN-based semiconductor lasers LD1, LD2, LD3, LD4, LD5, LD6, arrayed and fixed on the heat block 10. And LD7, collimator lenses 11, 12, 13, 14, 15, 16, and 17 provided corresponding to each of the GaN-based semiconductor lasers LD1 to LD7, one condenser lens 20, and one multi-lens. Mode optical fiber 30. The number of semiconductor lasers is not limited to seven. For example, as many as 20 semiconductor laser beams can be incident on a multimode optical fiber having a cladding diameter = 60 μm, a core diameter = 50 μm, and NA = 0.2. In addition, the number of optical fibers can be further reduced.
[0022]
The GaN-based semiconductor lasers LD1 to LD7 all have the same oscillation wavelength (for example, 405 nm), and the maximum output in continuous operation is all the same (for example, 100 mW for the multimode laser and 30 mW for the single mode laser). . As the GaN-based semiconductor lasers LD1 to LD7, lasers having an oscillation wavelength other than the above 405 nm in a wavelength range of 350 nm to 450 nm may be used. A suitable wavelength range will be described later.
[0023]
As shown in FIGS. 6 and 7, the above combined laser light source is housed in a box-shaped package 40 having an upper opening together with other optical elements. The package 40 includes a package lid 41 created so as to close the opening thereof. After the deaeration process, a sealing gas is introduced, and the package 40 and the package lid 41 are closed by closing the opening of the package 40 with the package lid 41. The combined laser light source is hermetically sealed in a closed space (sealed space) formed by 41.
[0024]
A base plate 42 is fixed to the bottom surface of the package 40, and the heat block 10, a condensing lens holder 45 that holds the condensing lens 20, and the multimode optical fiber 30 are disposed on the top surface of the base plate 42. A fiber holder 46 that holds the incident end is attached. The exit end of the multimode optical fiber 30 is drawn out of the package from an opening formed in the wall surface of the package 40.
[0025]
Further, a collimator lens holder 44 is attached to the side surface of the heat block 10, and the collimator lenses 11 to 17 are held. An opening is formed in the lateral wall surface of the package 40, and wiring 47 for supplying a driving current to the GaN-based semiconductor lasers LD1 to LD7 is drawn out of the package through the opening.
[0026]
In FIG. 7, in order to avoid complication of the figure, only the GaN semiconductor laser LD7 is numbered among the plurality of GaN semiconductor lasers, and only the collimator lens 17 is numbered among the plurality of collimator lenses. doing.
[0027]
FIG. 8 shows the front shape of the attachment part of the collimator lenses 11-17. Each of the collimator lenses 11 to 17 is formed in a shape obtained by cutting a region including the optical axis of a circular lens having an aspherical surface into a long and narrow plane. This elongated collimator lens can be formed, for example, by molding resin or optical glass. The collimator lenses 11 to 17 are closely arranged in the arrangement direction of the light emitting points so that the length direction is orthogonal to the arrangement direction of the light emitting points of the GaN-based semiconductor lasers LD1 to LD7 (left and right direction in FIG. 8).
[0028]
On the other hand, each of the GaN-based semiconductor lasers LD1 to LD7 includes an active layer having a light emission width of 2 μm, and each of the laser beams B1 in a state parallel to the active layer and a divergence angle in a direction perpendicular to the active layer, respectively, for example A laser emitting ~ B7 is used. These GaN-based semiconductor lasers LD1 to LD7 are arranged so that the light emitting points are arranged in a line in a direction parallel to the active layer.
[0029]
Accordingly, in the laser beams B1 to B7 emitted from the respective light emitting points, the direction in which the divergence angle is large coincides with the length direction and the divergence angle is small with respect to the elongated collimator lenses 11 to 17 as described above. Incident light is incident in a state where the direction coincides with the width direction (direction perpendicular to the length direction). That is, the collimator lenses 11 to 17 have a width of 1.1 mm and a length of 4.6 mm, and the horizontal and vertical beam diameters of the laser beams B1 to B7 incident thereon are 0.9 mm and 2. 6 mm. Each of the collimator lenses 11 to 17 has a focal length f. ₁ = 3 mm, NA = 0.6, and lens arrangement pitch = 1.25 mm.
[0030]
The condensing lens 20 is formed by cutting a region including the optical axis of a circular lens having an aspheric surface into a long and narrow shape in parallel planes, and is long in the arrangement direction of the collimator lenses 11 to 17, that is, in a horizontal direction and short in a direction perpendicular thereto. Is formed. The condenser lens 20 has a focal length f. ₂ = 23 mm, NA = 0.2. This condensing lens 20 is also formed by molding resin or optical glass, for example.
[0031]
Each of the laser beams B1, B2, B3, B4, B5, B6, and B7 emitted in a divergent light state from each of the GaN-based semiconductor lasers LD1 to LD7 constituting the combined laser light source has a corresponding collimator lens 11-17. Is collimated. The collimated laser beams B <b> 1 to B <b> 7 are collected by the condenser lens 20 and converge on the incident end face of the core 30 a of the multimode optical fiber 30.
[0032]
In this example, the collimator lenses 11 to 17 and the condenser lens 20 constitute a condensing optical system, and the condensing optical system and the multimode optical fiber 30 constitute a multiplexing optical system. That is, the laser beams B1 to B7 condensed as described above by the condenser lens 20 enter the core 30a of the multimode optical fiber 30 and propagate through the optical fiber to be combined with one laser beam B. The wave is emitted from the multimode optical fiber 30.
[0033]
In each laser module, when the coupling efficiency of the laser beams B1 to B7 to the multimode optical fiber 30 is 0.85 and each output of the GaN-based semiconductor lasers LD1 to LD7 is 30 mW, the light arranged in an array For each of the fibers 31, a combined laser beam B with an output of 180 mW (= 30 mW × 0.85 × 7) can be obtained in continuous operation.
[0034]
In the above combined laser light source, each of the GaN-based semiconductor lasers LD1 to LD7 can be pulse-driven to obtain laser light having a predetermined pulse width. Heat generation is suppressed by irradiating the laser beam in pulses, and fiber damage (damage to the cloth) due to heat is prevented.
[0035]
The peak power of each pulse is preferably 300 mW to 3 W. When the peak power is 300 mW, the pulse width is 10 nsec (nanosecond) to 10 μsec (microsecond), and the number of pulses per second is 10 ⁴ -10 ⁷ Is preferred. In this case, the duty is about 10%. When the peak power is 3 W, the pulse width is 1 nsec to 1 μsec and the number of pulses per second is 10 ⁴ -10 ⁷ Is preferred. In this case, the duty is about 1.0%.
[0036]
Note that, as described above, the GaN-based semiconductor laser is less likely to cause damage to the light emitting end face called COD (catalytic optical damage), has high reliability, and can realize high peak power.
[0037]
[Operation of bleaching equipment]
Next, the operation of the above-described bleaching apparatus will be described.
[0038]
When the cloth 200 before dyeing that has undergone a scouring process for removing contaminants such as oil adhering to the fiber and a desizing process for removing glue is supplied to the bleaching apparatus, the cloth 200 is rotated along with the rotation of the conveying roller 202. It is conveyed in the direction of arrow A and immersed in the chemical solution 204 in the chemical solution tank 206. The immersion time is preferably 0.1 to 1 hour.
[0039]
The chemical liquid 204 contains an oxidizing agent or a reducing agent at a predetermined concentration. As an oxidizing agent, hydrogen peroxide (H ₂ O ₂ ), Sodium perborate (NaBO) ₃ ・ 4H ₂ O), potassium permanganate (KMnO) ₄ ), Bleaching powder (CaCl · ClO), sodium hypochlorite (NaClO), sodium chlorite (NaClO) ₂ Chlorine compounds such as) can be used. As a reducing agent, hydrosulfite (Na ₂ S ₂ O ₄ ), Sodium tetrahydroborate (NaBH) ₄ ) Etc. can be used. Among these, sodium tetrahydroborate having a weak redox action is particularly preferable from the viewpoint of suppressing fiber damage.
[0040]
As the solvent, water, lower alcohols such as methanol and ethanol can be used. The concentration of the oxidizing agent or reducing agent is preferably 1% to 10%. In addition, an activation aid for activating the oxidizing agent and the reducing agent may be appropriately added to the chemical solution 204.
[0041]
Next, the cloth 200 taken out from the chemical solution tank 206 is supplied to the laser irradiation unit 208 in a state of being impregnated with the chemical solution 204. In the laser irradiation unit 208, the laser light emitted from the fiber array light source 506 of the irradiation head 500 is condensed only in the direction orthogonal to the arrangement direction of the emission ends of the optical fiber 30 by the cylindrical lens 510, and the surface of the cloth 200 An image is formed in a line shape on 56. The cylindrical lens 510 functions as, for example, an enlarging optical system that expands the beam diameter at a magnification of 3 times in the short axis direction and 1 time in the long axis direction. Further, the cloth 200 is conveyed at a constant speed, and is sub-scanned in the direction opposite to the conveying direction by the line beam 502 from the irradiation head 500.
[0042]
In this way, by irradiating the cloth impregnated with the chemical liquid 204 with the laser beam, the coloring component adhering to the fiber and the oxidizing agent or reducing agent in the chemical liquid 204 are activated, and the reactivity of both is increased and good. Can achieve a good bleaching effect. In order to prevent the fiber from being damaged by heat and obtain an activation effect, the wavelength of the irradiated laser light is 350 nm to 450 nm, and more preferably 400 nm to 415 nm. On the other hand, when the reactivity of the oxidizing agent or the reducing agent is high, a wavelength of 400 nm or longer is preferable because the load on the optical system is small and high output of the semiconductor laser is easy.
[0043]
Here, the light density on the surface of the cloth 200 is calculated. In the combined laser light source of the irradiation head, when each output of the GaN-based semiconductor lasers LD1 to LD7 is 30 mW, the output 180 mW (= 30 mW × 0.85 × 7) for each of the optical fibers 30 arranged in an array. ) Combined laser beam B can be obtained. Therefore, in the case of a fiber array light source in which 1000 multimode optical fibers 30 are arranged in a row, the output in continuous operation at the laser emitting unit 68 is about 180 W.
[0044]
In the laser emitting section 68 of the fiber array light source 506, high-luminance light emitting points are arranged in a line along the main scanning direction as described above. A conventional fiber light source that couples laser light from a single semiconductor laser to a single optical fiber has a low output, so a desired output could not be obtained unless multiple rows are arranged. Since the combined laser light source used in the form has a high output, a desired output can be obtained even with a small number of columns, for example, one column.
[0045]
When a multi-mode optical fiber 30 is a step index type optical fiber having a cladding diameter = 125 μm, a core diameter = 50 μm, and NA = 0.2, the beam diameter at the laser emitting portion 68 is 50 μm × 125 mm. is there. When the beam diameter is expanded at a magnification of 3 times in the short axis direction and 1 time in the long axis direction, the area of the irradiation area 506 is 150 μm × 125 mm.
[0046]
In general, 2000mJ / cm for laser-assisted bleaching ² ~ 20000mJ / cm ² In this embodiment, the light density in this range can be easily realized by appropriately changing the number of fibers to be arrayed and the number of laser beams to be combined. it can. The light density on the exposed surface required for bleaching is 10,000 mJ / cm. ² Then, the peak power of the GaN-based semiconductor lasers LD1 to LD7 is 3 W, the pulse width is 100 nsec, and the number of pulses per second is 10 ⁵ When the surface of the cloth 200 is irradiated with a pulse under the condition of a duty of 1%, the light density on the exposed surface is 10 mJ / cm per pulse. ² And high-speed exposure can be performed at 1.4 cm / s.
[0047]
On the other hand, when an excimer laser is used in place of the combined laser light source of the GaN-based semiconductor laser, the repetition frequency becomes low, so that it takes about 10 times or more speed to expose the same region.
[0048]
As described above, in the bleaching processing apparatus of the present embodiment, using a fiber array light source in which high-power and high-intensity combined laser light sources are arrayed, a cloth impregnated with a chemical solution is pulsed with laser light, A high energy density can be obtained on the fabric surface. Thereby, at least one of a chemical | medical solution and a coloring component can be activated, a bleaching reaction can be accelerated | stimulated, and the high bleaching effect can be acquired. Further, since the duty of the laser pulse is 1%, heat generation is suppressed and fiber damage can be prevented.
[0049]
Further, in the bleaching processing apparatus of the present embodiment, since a combined laser light source composed of a semiconductor laser capable of continuous driving and excellent in output stability is used for the laser irradiation unit, bleaching processing using an excimer laser is used. Compared with an apparatus, pulse driving can be performed at an arbitrary repetition frequency and pulse width, and by setting the repetition frequency high, bleaching can be performed several times faster. In addition, compared with a bleaching apparatus using an excimer laser, energy efficiency is as high as 10% to 20%, maintenance is easy, and cost is low.
[0050]
In particular, since GaN-based semiconductor lasers are covalently bonded, the light emission end face called COD (catalytic optical damage) is not easily damaged, is highly reliable, and can achieve high peak power. For example, a high peak power of 3 W can be realized under the conditions of a pulse width of 100 nsec and a duty of 1%. In this case, the average output is 30 mW.
[0051]
Moreover, in the bleaching processing apparatus of this Embodiment, a line beam can be easily obtained with the array arrangement of the optical fiber of a fiber array light source. Usually, since a textile product is formed in a long shape, it is reasonable to irradiate a laser beam with a line beam that is narrowed in the short axis direction and expanded in the long axis direction perpendicular thereto. Further, by increasing the number of optical fibers to be arrayed, the line beam length can be extended while maintaining the energy intensity and its uniformity. Further, since laser light having a wavelength of 350 to 450 nm is used, it is not necessary to generate a line beam using an optical system of a special material corresponding to ultraviolet rays, and the cost is low.
[0052]
Next, a modification of the bleaching apparatus described above will be described.
[Multihead]
In the above embodiment, an example in which a laser irradiation unit including a single irradiation head is provided has been described. However, when the length of the line beam in the long axis direction is insufficient, a plurality of irradiation heads are arranged in the long axis direction. You may arrange in.
[0053]
[Semiconductor laser]
In the above description, an example in which a GaN-based semiconductor laser with an oscillation wavelength of 350 nm to 450 nm that can be expected to be further increased in the future has been described. However, the semiconductor laser is not limited to a GaN-based semiconductor laser. For example, a nitride semiconductor laser composed of a group III element (Al, Ga, In) and nitrogen can be used. Nitride semiconductor is Al _x Ga _y In _1-xy It may be composed of any composition represented by N (x + y ≦ 1). A semiconductor laser having an oscillation wavelength of 200 nm to 450 nm can be obtained by appropriately changing the composition.
[0054]
[Other examples of magnifying optical systems]
As shown in FIGS. 9A and 9B, the irradiation head 500 is arranged along the direction in which the emission ends (light emitting points) of a large number (for example, 1000) of optical fibers 30 are orthogonal to the sub-scanning direction. A fiber array light source 506 provided with laser emission units arranged in a row, and a first light that condenses laser light emitted from the fiber array light source 506 only in a direction orthogonal to the arrangement direction of the emission ends of the optical fibers 30 A laser beam condensed in a direction orthogonal to the arrangement direction of the cylindrical lens 512 and the emission end of the optical fiber 30 is condensed only in the arrangement direction to form an image on the surface (scanning surface) 56 of the cloth 200. The cylindrical lens 514 can be configured.
[0055]
The first cylindrical lens 512 has a curvature in a predetermined direction and has a long shape in a direction orthogonal to the predetermined direction, and the longitudinal direction (direction orthogonal to the predetermined direction) is the arrangement direction of the emission ends of the optical fibers 30. Are arranged in parallel with each other. The second cylindrical lens 514 has a curvature in a predetermined direction and has a long shape in the predetermined direction so that the curvature direction (predetermined direction) is parallel to the arrangement direction of the emission ends of the optical fibers 30. Is arranged.
[0056]
In this irradiation head, the laser light emitted from the fiber array light source 506 is condensed in a direction orthogonal to the arrangement direction of the emission ends of the optical fiber 30 by the first cylindrical lens 512, and light is emitted by the second cylindrical lens 514. The light is condensed in the arrangement direction of the emission ends of the fibers 30 and imaged in a line on the scanning plane 56.
[0057]
These cylindrical lenses 512 and 514 function as, for example, an expansion optical system that expands the beam diameter at a magnification of 3 times in the short axis direction and 10 times in the long axis direction. In FIG. 35, the cloth 200 is transported at a constant speed, and is sub-scanned in the direction opposite to the transport direction by the line beam from the irradiation head 500. Thus, a wide exposure surface can be exposed by expanding the beam of the fiber array light source by the optical system. Further, by expanding the beam, a deeper depth of focus can be obtained, and the cloth conveyed at high speed can be illuminated uniformly.
[0058]
Here, the light density on the exposure surface is calculated. When a multimode laser having a peak power of 6 W is used as the combined laser light source of the irradiation head, a combined laser beam B having a peak power of 36 W can be obtained from seven LDs. Therefore, in the case of a fiber array light source in which 1000 multimode optical fibers 30 are arranged in a row, the peak power at the laser emitting section 68 is about 36 kW.
[0059]
When a multi-mode optical fiber 30 is a step index type optical fiber having a cladding diameter = 125 μm, a core diameter = 50 μm, and NA = 0.2, the beam diameter at the laser emitting portion 68 is 50 μm × 125 mm. is there. When the beam diameter is expanded at a magnification of 3 times in the short axis direction and 10 times in the long axis direction, the area of the irradiation area 506 is 150 μm × 1250 mm. Therefore, peak power 6W, pulse width 100nsec, duty 1%, number of pulses per second 10 ⁵ When the surface of the cloth 200 is irradiated with a pulse under the above conditions, the light density on the exposed surface is 2 mJ / cm2 per pulse. ² It is. Even if the loss due to the optical system is estimated to be about 80%, the light density on the exposure surface is 1.5 mJ / cm per pulse. ² It is. Therefore, 10,000 mJ / cm ² Can be exposed at a high speed at 0.2 cm / s.
[0060]
[Modification of optical fiber]
In the above embodiment, an example in which a uniform optical fiber with a cladding diameter of 125 μm is used for the combined laser light source has been described. However, the cladding diameter of the output end of the optical fiber can be made smaller than the cladding diameter of the incident end. . By reducing the cladding diameter of the output end of the optical fiber, the diameter of the light emitting section is further reduced, and the brightness of the fiber array light source can be increased.
[0061]
For example, as shown in FIG. 10A, an optical fiber having the same core diameter as that of the multimode optical fiber 30 and a cladding diameter smaller than that of the multimode optical fiber 30 is provided at the other end of the multimode optical fiber 30 of the laser module 64. 31 can be combined. As shown in FIG. 10B, the emission end of the optical fiber 31 is sandwiched and fixed between two support plates 65 having a flat surface. Further, a transparent protective plate 63 such as glass is disposed on the light emitting side of the optical fiber 31 in order to protect the end face of the optical fiber 31. The protection plate 63 may be disposed in close contact with the end surface of the optical fiber 31 or may be disposed so that the end surface of the optical fiber 31 is sealed. The exit end portion of the optical fiber 31 has a high light density and is likely to collect dust and easily deteriorate. However, the protective plate 63 can prevent the dust from adhering to the end face and can also delay the deterioration.
[0062]
In this example, in order to arrange the emission ends of the optical fibers 31 with a small cladding diameter in a line without any gaps, the multimode optical fiber 30 is placed between two adjacent multimode optical fibers 30 at a portion with a large cladding diameter. Two exit ends of the optical fiber 31 coupled to two adjacent multi-mode optical fibers 30 where the exit ends of the optical fibers 31 coupled to the stacked multi-mode optical fibers 30 are adjacent to each other at a portion where the cladding diameter is large. Are arranged so as to be sandwiched between them.
[0063]
For example, as shown in FIG. 11, an optical fiber 31 having a length of 1 to 30 cm and having a small cladding diameter is coaxially connected to the tip of the multimode optical fiber 30 having a large cladding diameter on the laser light emission side. Can be obtained by linking them together. In the two optical fibers, the incident end face of the optical fiber 31 is fused and joined to the outgoing end face of the multimode optical fiber 30 so that the central axes of both optical fibers coincide. As described above, the diameter of the core 31 a of the optical fiber 31 is the same as the diameter of the core 30 a of the multimode optical fiber 30.
[0064]
In addition, a short optical fiber in which an optical fiber having a short cladding diameter and a large cladding diameter is fused to an optical fiber having a short cladding diameter and a large cladding diameter may be coupled to the output end of the multimode optical fiber 30 via a ferrule or an optical connector. Good. By detachably coupling using a connector or the like, the tip portion can be easily replaced when an optical fiber having a small cladding diameter is broken, and the cost required for the irradiation head maintenance can be reduced. Hereinafter, the optical fiber 31 may be referred to as an emission end portion of the multimode optical fiber 30.
[0065]
The multimode optical fiber 30 and the optical fiber 31 may be any of a step index type optical fiber, a graded index type optical fiber, and a composite type optical fiber. For example, a step index type optical fiber manufactured by Mitsubishi Cable Industries, Ltd. can be used. In the present embodiment, the multimode optical fiber 30 and the optical fiber 31 are step index type optical fibers, and the multimode optical fiber 30 has a cladding diameter = 125 μm, a core diameter = 25 μm, NA = 0.2, an incident end face. The transmittance of the coat is 99.5% or more, and the optical fiber 31 has a cladding diameter = 60 μm, a core diameter = 25 μm, and NA = 0.2.
[0066]
In general, in laser light in the infrared region, propagation loss increases as the cladding diameter of the optical fiber is reduced. For this reason, a suitable cladding diameter is determined according to the wavelength band of the laser beam. However, the shorter the wavelength, the smaller the propagation loss. In the case of laser light having a wavelength of 405 nm emitted from a GaN-based semiconductor laser, the cladding thickness {(cladding diameter−core diameter) / 2} is set to infrared light in the wavelength band of 800 nm. The propagation loss hardly increases even if it is about ½ of the case of propagating infrared light and about ¼ of the case of propagating infrared light in the 1.5 μm wavelength band for communication. Therefore, the cladding diameter can be reduced to 60 μm.
[0067]
However, the cladding diameter of the optical fiber 31 is not limited to 60 μm. The clad diameter of an optical fiber used in a conventional fiber light source is 125 μm, but the depth of focus becomes deeper as the clad diameter becomes smaller. Therefore, the clad diameter of a multimode optical fiber is preferably 80 μm or less, more preferably 60 μm or less. Preferably, it is 40 μm or less. On the other hand, since the core diameter needs to be at least 3 to 4 μm, the cladding diameter of the optical fiber 31 is preferably 10 μm or more.
[0068]
In the above, a fiber array light source is formed by coupling another optical fiber having the same core diameter as the multimode optical fiber and a cladding diameter smaller than the multimode optical fiber to the output end of the multimode optical fiber of the combined laser light source. However, for example, a multimode optical fiber having a cladding diameter smaller than 125 μm (for example, 80 μm, 60 μm, etc.) may be used without coupling another optical fiber to the output end. Good. By reducing the exit beam diameter of the fiber array light source in this way, the magnifying optical system can be used as described above, and a deep focal depth can be obtained. Thereby, the cloth conveyed at high speed can be illuminated uniformly.
[0069]
[Other combined laser light sources]
The combined laser light source is not limited to one that combines laser beams emitted from a plurality of chip-shaped semiconductor lasers.
[0070]
(Multiple cavity laser combined laser source)
For example, as shown in FIG. 12, a combined laser light source including a chip-shaped multicavity laser 110 in which a plurality of (for example, three) light emitting points 110a are arranged in a predetermined direction can be used. This combined laser light source is configured to include a multi-cavity laser 110, one multi-mode optical fiber 130, and a condensing lens 120. The multi-cavity laser 110 can be composed of, for example, a GaN-based laser diode having an oscillation wavelength of 405 nm.
[0071]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110 a of the multicavity laser 110 is collected by the condenser lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted.
[0072]
A plurality of light emitting points 110 a of the multi-cavity laser 110 are juxtaposed within a width substantially equal to the core diameter of the multi-mode optical fiber 130, and a focal point substantially equal to the core diameter of the multi-mode optical fiber 130 is used as the condenser lens 120. By using a convex lens of a distance or a rod lens that collimates the outgoing beam from the multicavity laser 110 only in a plane perpendicular to the active layer, the coupling efficiency of the laser beam B to the multimode optical fiber 130 can be increased. it can.
[0073]
Further, as shown in FIG. 13, a multi-cavity laser 110 having a plurality of (for example, three) emission points is used, and a plurality of (for example, nine) multi-cavity lasers 110 are equidistant from each other on the heat block 111. A combined laser light source including the laser array 140 arranged in (1) can be used. The plurality of multi-cavity lasers 110 are arranged and fixed in the same direction as the arrangement direction of the light emitting points 110a of each chip.
[0074]
This combined laser light source includes a laser array 140, a plurality of lens arrays 114 arranged corresponding to each multi-cavity laser 110, and a single lens arranged between the laser array 140 and the plurality of lens arrays 114. A rod lens 113, one multimode optical fiber 130, and a condenser lens 120 are provided. The lens array 114 includes a plurality of microlenses corresponding to the emission points of the multi-cavity laser 110.
[0075]
In the above configuration, each of the laser beams B emitted from each of the plurality of light emitting points 110a of the plurality of multi-cavity lasers 110 is condensed in a predetermined direction by the rod lens 113 and then each microlens of the lens array 114. Is collimated. The collimated laser beam L is condensed by the condenser lens 120 and enters the core 130a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted. Thus, by using a multi-cavity laser, the output per optical fiber can be improved, and the cost per optical fiber can be reduced.
[0076]
(Multiple laser light source using multi-stage laser array)
Furthermore, examples of other combined laser light sources are shown. In this combined laser light source, as shown in FIGS. 14A and 14B, a heat block 182 having an L-shaped cross section in the optical axis direction is mounted on a substantially rectangular heat block 180, and two heats are provided. A storage space is formed between the blocks. On the upper surface of the L-shaped heat block 182, a plurality of (for example, two) multi-cavity lasers 110 in which a plurality of light emitting points (for example, five) are arranged in an array form the light emitting points 110a of each chip. It is arranged and fixed at equal intervals in the same direction as the arrangement direction. In this case, the single transverse mode may be used as the light emitting point, but the stripe width is slightly widened to obtain the multi transverse mode, and the use of the multi transverse mode can increase the output. Therefore, high-speed exposure is possible by using this light source for the exposure apparatus.
[0077]
A concave portion is formed in the substantially rectangular heat block 180, and a plurality of (for example, two) light emitting points (for example, five) are arranged in an array on the upper surface of the space side of the heat block 180. The multi-cavity laser 110 is arranged such that its emission point is located on the same vertical plane as the emission point of the laser chip arranged on the upper surface of the heat block 182.
[0078]
On the laser beam emission side of the multi-cavity laser 110, a collimator lens array 184 in which collimator lenses are arranged corresponding to the light emission points 110a of the respective chips is arranged. In the collimating lens array 184, the length direction of each collimating lens coincides with the direction in which the divergence angle of the laser beam is large (the fast axis direction), and the width direction of each collimating lens is in the direction in which the divergence angle is small (slow axis direction). They are arranged to match. Thus, collimating lenses are arrayed and integrated, thereby improving the space utilization efficiency of the laser light and increasing the output of the combined laser light source, and reducing the number of parts and reducing the cost. it can.
[0079]
Further, on the laser beam emitting side of the collimating lens array 184, there is one multimode optical fiber 130, and a condensing lens 120 that condenses and combines the laser beam at the incident end of the multimode optical fiber 130. Has been placed.
[0080]
In the above configuration, each of the laser beams emitted from each of the plurality of light emitting points 110a of the plurality of multi-cavity lasers 110 arranged on the laser blocks 180 and 182 is collimated by the collimating lens array 184 and collected. The light is condensed by the optical lens 120 and enters the core 130 a of the multimode optical fiber 130. The laser light incident on the core 130a propagates in the optical fiber, is combined into one, and is emitted. Also in this case, as in the case of using the multi-cavity laser, the output per optical fiber can be improved, and the cost per optical fiber can be reduced. Therefore, high-speed exposure is possible by using this light source for the exposure apparatus.
[0081]
As described above, this combined laser light source can achieve particularly high output by the multi-stage arrangement of multi-cavity lasers and the array of collimating lenses. By using this combined laser light source, a higher-intensity fiber array light source or bundle fiber light source can be configured, so that it is particularly suitable as a fiber light source constituting the laser light source of the irradiation head of the present embodiment.
[0082]
In this case, the light density on the exposure surface is calculated. By using a multi-lateral mode chip as a combined laser light source of the irradiation head, a combined laser beam having a peak power of 103 W can be obtained by 20 LDs when the peak power per light emitting point is 6 W. . Therefore, in the case of a fiber array light source in which 1750 multimode optical fibers are arranged in a line, the peak power at the laser emitting portion is 180 kW.
[0083]
In addition, when the same multimode optical fiber is used, the beam diameter at the laser emitting portion is 50 μm × 220 mm. When the beam diameter is expanded at a magnification of 3 times in the short axis direction and 10 times in the long axis direction, the area of the irradiation area is 150 μm × 2200 mm. Therefore, peak power 6W, pulse width 100nsec, duty 1%, number of pulses per second 10 ⁵ When the cloth surface is irradiated with a pulse under the above conditions, the light density on the exposed surface is 10 mJ / cm per pulse. ² It is. Even if the loss due to the optical system is estimated to be about 80%, the light density on the exposure surface is 8 mJ / cm per pulse. ² It is. Therefore, 10,000 mJ / cm ² In the case of exposing at a light density of 2, a cloth having a width of 2.2 m can be exposed at a high speed of 1.2 cm / s.
[0084]
It should be noted that a laser module in which each of the above combined laser light sources is housed in a casing and the emission end portion of the multimode optical fiber 130 is pulled out from the casing can be configured.
[0085]
【The invention's effect】
According to the bleaching processing apparatus of the present invention, it is possible to perform a bleaching process at a high energy density by irradiating a laser beam with a short pulse using a high-power and high-intensity combined laser light source. Can get. Moreover, according to the bleaching apparatus of this invention, the effect that a bleaching process can be performed at high speed and low cost with high energy efficiency can be acquired.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a bleaching apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration of a laser irradiation unit of a bleaching apparatus.
3A is a cross-sectional view in the fiber array direction along the optical axis showing the configuration of the irradiation head, and FIG. 3B is a cross-sectional view in the sub-scanning direction.
FIG. 4 is a perspective view showing a configuration of a fiber array light source.
FIG. 5 is a plan view showing a configuration of a combined laser light source.
FIG. 6 is a plan view showing a configuration of a laser module.
7 is a side view showing the configuration of the laser module shown in FIG. 6. FIG.
8 is a partial side view showing the configuration of the laser module shown in FIG. 6;
9A is a cross-sectional view in the fiber array direction along the optical axis showing another configuration of the irradiation head, and FIG. 9B is a cross-sectional view in the sub-scanning direction.
10A is a perspective view showing another configuration of the fiber array light source, and FIG. 10B is a partially enlarged view of FIG.
FIG. 11 is a diagram showing a configuration of a multimode optical fiber.
FIG. 12 is a plan view showing another configuration of the combined laser light source.
FIG. 13 is a plan view showing another configuration of the combined laser light source.
14A is a plan view showing another configuration of the combined laser light source, and FIG. 14B is a cross-sectional view taken along the optical axis of FIG.
[Explanation of symbols]
LD1-LD7 GaN semiconductor laser
10 Heat block
11-17 Collimator lens
20 Condensing lens
30 Multimode optical fiber
64 laser module
200 cloth
202 Conveying roller
204 Chemical
206 Chemical tank
208 Laser irradiation unit
500 Irradiation head
506 Fiber array light source
510 Cylindrical lens

Claims (3)

A chemical solution impregnation means for impregnating the fiber before dyeing with a chemical solution containing an oxidizing agent or a reducing agent;
A plurality of semiconductor lasers, a single optical fiber, and a condensing optical system that condenses laser beams emitted from each of the plurality of semiconductor lasers and couples the condensed beam to an incident end of the optical fiber. A laser irradiation means comprising a combined laser light source and irradiating the cloth impregnated with the chemical solution with a laser beam having a wavelength of 200 nm to 450 nm;
Bleaching equipment equipped with. A chemical solution impregnation means for impregnating the fiber before dyeing with a chemical solution containing an oxidizing agent or a reducing agent;
A laser beam emitted from each of a plurality of light emitting points of a semiconductor laser having a plurality of light emitting points, a single optical fiber, and a semiconductor laser having the plurality of light emitting points is condensed, A laser irradiation unit including a combined laser light source including a condensing optical system coupled to an incident end of an optical fiber, and irradiating the cloth impregnated with the chemical solution with a laser beam having a wavelength of 200 nm to 450 nm;
Bleaching equipment equipped with. The bleaching apparatus according to claim 1, wherein the laser irradiation unit irradiates a laser beam having a wavelength of 350 nm to 450 nm.

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