Method for generating a flying object, method for transferring a flying object, and image forming apparatus

Abstract

To provide a flying object generation method using an optical vortex laser capable of forming a high-resolution image.SOLUTION: There is provided a flying object generation method for generating from a light absorption material a liquid column or droplet with a smaller diameter than an irradiation diameter of an optical vortex laser beam in the irradiation direction of the optical vortex laser beam by irradiating a surface of a base material on the side opposite to the side where the light absorption material is arranged in the base material in which the light absorption material is arranged on the surface with the optical vortex laser beam. The flying object generation method adjusts an amount of the liquid column or the droplet by changing the orbital angular momentum quantum number of the optical vortex laser beam.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a flying object generation method, a flying object transfer method, and an image forming apparatus.

Background Art

[0002] In an image forming apparatus, since ink droplets can be made to fly to desired positions, in recent years, applications have been studied in fields such as 3D printers for three-dimensional modeling and printed electronics for forming electronic components by printing technology.

[0003] Specifically, there is a laser-induced forward transfer (LIFT) method in which a laser is irradiated from the transparent substrate side of a transfer target material (donor) layer formed on a transparent substrate, and the flying object is made to fly and transfer to a desired position on a receiver substrate disposed facing the flying object, and it has been studied for various applications. As a laser light source for LIFT, a method of transferring high-viscosity ink without scattering by using an optical vortex laser having a profile on a ring has been proposed (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a method capable of stably controlling the amount of a light-absorbing material that flies without scattering of the light-absorbing material.

Means for Solving the Problems

[0005] The flying object generation method of the present invention as means for solving the above problems is a flying object generation method in which an optical vortex laser beam is irradiated onto the surface of a base material on the side opposite to the side on which a light-absorbing material is disposed in a base material having the light-absorbing material disposed on its surface, thereby generating a liquid column or droplet having a diameter smaller than the irradiation diameter of the optical vortex laser beam in the irradiation direction of the optical vortex laser beam from the light-absorbing material. This method is characterized by adjusting the amount of liquid column or droplet by changing the orbital angular momentum quantum number of the optical vortex laser beam. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a method for generating flying objects that prevents the scattering of light-absorbing material and allows for stable control of the amount of light-absorbing material that flies. [Brief explanation of the drawing]

[0007] [Figure 1A] Figure 1A is a schematic diagram showing an example of a wavefront (equal phase surface) in a typical laser beam. [Figure 1B] Figure 1B shows an example of the light intensity distribution in a typical laser beam. [Figure 1C] Figure 1C shows an example of a phase distribution in a typical laser beam. [Figure 2A] Figure 2A is a schematic diagram showing an example of a wavefront (equal phase surface) in an optical vortex laser beam. [Figure 2B] Figure 2B shows an example of the light intensity distribution in an optical vortex laser beam. [Figure 2C] Figure 2C shows an example of a phase distribution in an optical vortex laser beam. [Figure 3A] Figure 3A is a photograph showing an example of what happens when a typical laser beam is irradiated onto a light-absorbing material. [Figure 3B] Figure 3B is a photograph showing an example of what happens when an optical vortex laser beam is irradiated onto a light-absorbing material. [Figure 4A] Figure 4A is an explanatory diagram showing an example of the results of spatial intensity distribution measurement in an optical vortex laser beam. [Figure 4B] Figure 4B is an explanatory diagram showing an example of the results of spatial intensity distribution measurement in a laser beam with a point of light intensity of 0 at its center. [Figure 5A] Figure 5A is an explanatory diagram showing an example of the image forming apparatus of the present invention. [Figure 5B] Figure 5B is an explanatory diagram showing another example of the image forming apparatus of the present invention. [Figure 5C] Figure 5C is an explanatory diagram showing another example of the image forming apparatus of the present invention. [Figure 6A] Figure 6A is a schematic cross-sectional view showing an example of the image forming apparatus shown in Figure 5B, with the addition of a light-absorbing material supply means and a means for transporting the object to be attached. [Figure 6B] Figure 6B is a schematic cross-sectional view showing another example of the image forming apparatus shown in Figure 5B, with the addition of a light-absorbing material supply means and a means for transporting the object to be attached. [Figure 7A] Figure 7A is a schematic cross-sectional view showing an example of the image forming apparatus shown in Figure 6A with a fixing means added. [Figure 7B] Figure 7B is a schematic cross-sectional view showing another example of the image forming apparatus shown in Figure 6A, with a fixing means added. [Figure 7C] Figure 7C is a schematic cross-sectional view showing another example of the image forming apparatus shown in Figure 6A, with a fixing means added. [Figure 8A] Figure 8A is a schematic cross-sectional view showing an example of the image forming apparatus of the present invention. [Figure 8B] Figure 8B is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. [Figure 9] Figure 9 is a schematic cross-sectional view showing an example of a manufacturing apparatus for three-dimensional objects according to the present invention. [Figure 10A] Figure 10A is a photograph showing an example of the flight state of the light-absorbing material in Example 1 when the orbital angular momentum quantum number is set to 1. [Figure 10B] Figure 10B is a photograph showing an example of the flight state of the light-absorbing material in Example 1 when the orbital angular momentum quantum number is set to 2. [Figure 10C] Figure 10C is a photograph showing an example of the flight state of the light-absorbing material in Example 1 when the orbital angular momentum quantum number is set to 3. [Figure 11] Figure 11 shows the relationship between the quantum number of orbital angular momentum (L) and the quantum number in the radial direction (P), and the wavefront shape of the optical vortex laser beam. [Figure 12A] Figure 12A is a photograph showing an example of a dot in Example 1 when the orbital angular momentum quantum number is set to 1. [Figure 12B] FIG. 12B is a photograph showing an example of dots when the orbital angular momentum quantum number is 2 in Example 1. [Figure 12C] FIG. 12C is a photograph showing an example of dots when the orbital angular momentum quantum number is 3 in Example 1. [Figure 13] FIG. 13 is a photograph showing an example of dots when the orbital angular momentum quantum number is 1 in Example 3. [Figure 14A] FIG. 14A is a photograph showing an example of a wire when the orbital angular momentum quantum number is 1 in Example 3. [Figure 14B] FIG. 14B is a photograph showing an example of a wire when the orbital angular momentum quantum number is 2 in Example 3. [Figure 15] FIG. 15 is a photograph showing an example of a wire with a Gaussian beam in Comparative Example 2.

BEST MODE FOR CARRYING OUT THE INVENTION

[0008] (Flying Object Generation Method, Flying Object Transfer Method, and Image Forming Apparatus) The flying object generation method of the present invention irradiates the surface of a substrate on the side opposite to the side where the light absorbing material is disposed with an optical vortex laser beam on the surface of the substrate having the light absorbing material disposed thereon, thereby generating a liquid column or liquid droplets having a diameter smaller than the irradiation diameter of the optical vortex laser beam in the irradiation direction of the optical vortex laser beam from the light absorbing material. The method is a flying object generation method, and the amount of the liquid column or liquid droplets is adjusted by changing the orbital angular momentum quantum number of the optical vortex laser beam. [ The flying object transfer method of the present invention irradiates the surface of a substrate on the side opposite to the side where the light absorbing material is disposed with an optical vortex laser beam on the surface of the substrate having the light absorbing material disposed thereon, thereby generating a liquid column or liquid droplets having a diameter smaller than the irradiation diameter of the optical vortex laser beam in the irradiation direction of the optical vortex laser beam from the light absorbing material, and adjusting the amount of the liquid column or liquid droplets by changing the orbital angular momentum quantum number of the optical vortex laser beam. The liquid column or liquid droplets are brought into contact with a transfer medium and transferred. In other words, the projectile transfer method of the present invention involves bringing a small-diameter liquid column or droplet, generated from a light-absorbing material by the projectile generation method of the present invention, into contact with a transfer medium and transferring it. Therefore, since the explanation of the projectile transfer method of the present invention is sufficient to describe the projectile generation method using the optical vortex laser of the present invention, the details of the projectile generation method using the optical vortex laser of the present invention will also be revealed through the explanation of the image formation method of the present invention.

[0009] The present invention relates to a method for generating projectiles that, in conventional laser-based projectile formation methods, can achieve projectile flight with reduced scattering due to the effect of optical vortices by launching a high-viscosity ink, which is the material to be transferred, onto an acceptor substrate. However, it does not address a method for controlling the amount of the material to be transferred (donor), which is necessary for applications in image forming apparatuses, etc., and is based on the finding that it is difficult to stably transfer minute amounts necessary for high-resolution image formation.

[0010] Therefore, we have found that the image forming method of the present invention can adjust (control) the amount of liquid columns or droplets of an optical vortex laser beam by changing the orbital angular momentum quantum number of the optical vortex laser beam.

[0011] First, let me explain optical vortex laser beams. Typical laser beams have aligned phases and therefore possess a planar equiphase surface (wavefront), as shown in Figure 1A. Because the direction of the laser beam's Poynting vector is perpendicular to the planar equiphase surface, it aligns with the direction of the laser beam's irradiation. Therefore, when a laser beam irradiates a light-absorbing material, a force acts on the material in the direction of irradiation. However, the light intensity distribution in the cross-section of the laser beam is a normal distribution (Gaussian distribution) with the strongest intensity at the center of the beam, as shown in Figure 1B, making the light-absorbing material prone to scattering. Furthermore, observation of the phase distribution reveals the absence of a phase difference, as shown in Figure 1C. Figure 2A is a schematic diagram showing an example of a wavefront (equiphase surface) in an optical vortex laser beam. A Laguerre-Gauss beam, one type of optical vortex laser beam, has a helical equiphase surface as shown in Figure 2A. Also, as shown in Figure 2B, the light intensity distribution has a concave, annular distribution where the center of the beam is zero. Because the direction of the Poynting vector of the optical vortex laser beam is perpendicular to the helical equiphase surface, the Poynting vector is slightly tilted with respect to the direction of propagation of the optical vortex laser beam. As a result, light pressure, i.e., orbital angular momentum, appears in the cross-section of the laser beam along the direction of rotation of the annulus. When an optical vortex laser beam is irradiated onto a light-absorbing material, a force acts along the direction of rotation of the annulus. Therefore, the light-absorbing material irradiated with an optical vortex laser beam flies along the direction of irradiation of the optical vortex laser beam and adheres to the object it is attached to in a state where it is less likely to scatter. Furthermore, observation of the phase distribution confirms that a phase difference occurs, as shown in Figure 2C.

[0012] Figure 3A is a photograph showing an example of what happens when a typical laser beam is irradiated onto a light-absorbing material. Figure 3B is a photograph showing an example of what happens when an optical vortex laser beam is irradiated onto a light-absorbing material. Comparing Figure 3A and Figure 3B, it can be seen that the light-absorbing material is more scattered in Figure 3A than in Figure 3B. From this, it can be seen that when the light-absorbing material is irradiated with an optical vortex laser beam, annular energy is applied as radiation pressure, causing it to fly along the direction of irradiation of the optical vortex laser beam, and due to the influence of orbital angular momentum, it adheres to the object to which it is attached in a state that makes it less likely to scatter.

[0013] There are no particular restrictions on the method for determining whether or not a laser beam is an optical vortex laser beam; it can be appropriately selected depending on the purpose. Examples include observing the phase distribution and measuring the spatial intensity distribution, with spatial intensity distribution measurement being the most common. Spatial intensity distribution can be observed using a laser beam profiler (such as a laser beam profiler from Spiricon Corporation or Hamamatsu Photonics K.K.), and an example of the spatial intensity distribution measurement results is shown in Figures 4A and 4B. Figure 4A is an explanatory diagram showing an example of the results of spatial intensity distribution measurement in an optical vortex laser beam, and Figure 4B is an explanatory diagram showing an example of the results of spatial intensity distribution measurement in a laser beam with a point of light intensity of 0 at its center. When the spatial intensity distribution of an optical vortex laser beam is measured, as shown in Figure 4A, it can be confirmed that the spatial intensity distribution is annular, and that the laser beam has a point of zero light intensity at its center, similar to Figure 1C. On the other hand, when the spatial intensity distribution of a typical laser beam with a point of zero light intensity at its center is measured, as shown in Figure 4B, it is similar to the spatial intensity distribution measurement of the optical vortex laser beam shown in Figure 4A. However, since the energy distribution of the annular region is not uniform, a difference from the optical vortex laser beam can be confirmed.

[0014] The image forming method of the present invention can be suitably carried out using the image forming apparatus of the present invention.

[0015] The image forming apparatus of the present invention irradiates a vortex laser beam onto the surface of a substrate on which a light-absorbing material is placed, on the side opposite to the side where the light-absorbing material is placed. As a result, the image forming apparatus of the present invention generates a liquid column or droplet from the light-absorbing material in the direction of irradiation of the vortex laser beam and with a diameter smaller than the irradiation diameter of the vortex laser beam, and brings the liquid column or droplet into contact with the transfer medium to transfer the image. The image forming apparatus preferably includes a light-absorbing material flight means and a transfer means, and further includes other means as needed.

[0016] <Means of launching light-absorbing materials> The light-absorbing material flight means involves irradiating the surface of a substrate on which a light-absorbing material is placed with an optical vortex laser beam onto the surface of the substrate opposite to the side on which the light-absorbing material is placed, thereby generating liquid columns or droplets from the light-absorbing material in the direction of the optical vortex laser beam irradiation and with a diameter smaller than the irradiation diameter of the optical vortex laser beam, and adjusting the amount of the liquid columns or droplets by changing the orbital angular momentum quantum number of the optical vortex laser beam.

[0017] The light-absorbing material flight means in the present invention can adjust the amount of liquid column or droplet by changing the orbital angular momentum quantum number of the optical vortex laser beam. The orbital angular momentum mentioned above is the momentum excluding the spin angular momentum from the total angular momentum. Figure 11 is a schematic diagram showing the relationship between the quantum number of orbital angular momentum (L) and the quantum number in the radial direction (P), and the wavefront shape of the optical vortex laser beam. As shown in Figure 11, as the orbital angular momentum quantum number (L) increases, the intensity distribution of the optical vortex laser beam broadens, and the region of the singularity (center) in the annular shape of the optical vortex laser beam widens. This allows for adjustment of the amount of liquid column or droplet. There are no particular restrictions on the orbital angular momentum quantum number, and it can be appropriately selected depending on the purpose, but it is preferably between 1 and 3. When the orbital angular momentum quantum number is 3 or less, separation of the central singularity is prevented, and a relatively stable beam shape can be obtained.

[0018] Furthermore, the light-absorbing material flight means can include, for example, a laser light source, an optical vortex conversion unit, and a polarization conversion unit, and it is preferable that the light-absorbing material flight means further includes other components as needed.

[0019] <This is a laser light source>> There are no particular restrictions on the laser light source, and it can be appropriately selected according to the purpose. Examples include solid-state lasers, gas lasers, and semiconductor lasers that generate a laser beam, and those capable of pulsed oscillation are preferred. Examples of solid-state lasers include YAG lasers and titanium-sapphire lasers. Examples of gas lasers include argon lasers, helium-neon lasers, and carbon dioxide lasers. Among these, semiconductor lasers with an output of about 30 mW are preferred in terms of miniaturization and cost reduction of the device. There are no particular restrictions on the wavelength of the laser beam, and it can be appropriately selected according to the purpose, but it is preferably 300 nm to 11 μm, and more preferably 350 nm to 1100 nm. There are no particular restrictions on the beam diameter of the laser beam, and it can be appropriately selected according to the purpose, but it is preferably 1 μm to 1 mm, and more preferably 1 μm to 100 μm. There are no particular restrictions on the pulse width of the laser beam, and it can be appropriately selected according to the purpose, but it is preferably 0.01 nanoseconds or more and 100 nanoseconds or less, and more preferably 0.01 nanoseconds or more and 10 nanoseconds or less. There are no particular restrictions on the pulse frequency of the laser beam, and it can be appropriately selected depending on the purpose, but 500 Hz or higher is preferred. Furthermore, any laser light source capable of outputting an optical vortex laser beam may be used as the laser light source.

[0020] <<Optical Vortex Conversion Unit>> The optical vortex conversion unit is not particularly limited as long as it can convert a laser beam into an optical vortex laser beam, and can be appropriately selected depending on the purpose. Examples include a spatial light modulator, a helical phase plate, and a multimode fiber. Among these, a spatial light modulator is preferred because it can modulate the amplitude and phase of the laser.

[0021] Furthermore, methods for generating an optical vortex laser beam are not limited to methods using an optical vortex conversion unit. Other methods include, for example, oscillating an optical vortex as an inherent mode from a laser resonator, or inserting a holographic element into the resonator. Other methods for generating an optical vortex laser beam include, for example, using excitation light converted into a donut beam, using a resonator mirror with a dark spot, or using the thermal lens effect generated by a side-excited solid-state laser as a spatial filter to generate an optical vortex mode.

[0022] <<Polarization conversion section>> The polarization conversion unit imparts circular polarization to the optical vortex laser beam. Examples of polarization conversion units include quarter-wave plates. The optical axis is set at +45° or -45° to impart circular polarization to the optical vortex laser beam. Equation (1) below is the equation for the total angular momentum density, which is the sum of the orbital angular momentum and the spin angular momentum of the polarization. It shows the distribution of the total angular momentum density, which is the sum of the orbital angular momentum and the spin angular momentum derived from the polarization, and is thought to contribute to the rotational speed of the liquid column generated during laser irradiation. The rotation of the liquid column allows the image forming apparatus to stably propagate the light-absorbing material and greatly enhance the effect of adhering it to the object in a shape that suppresses scattering.

[0023] [ka] However, in equation (1), ε0 is the permittivity of vacuum, ω is the angular frequency of light, L is the orbital angular momentum quantum number, I is the intensity of the optical vortex laser beam represented by equation (2) below, S is the spin angular momentum quantum number with respect to polarization, and r is the radial vector of the cylindrical coordinate system. [ka] However, in equation (2), ω0 is the beam waist size of the light. Beam waist size refers to the minimum beam diameter in an optical vortex laser beam.

[0024] The spin angular momentum quantum number S has values ​​of 0 and ±1, where the sign represents the direction of circular polarization (clockwise and counterclockwise), and is 0 for linear polarization.

[0025] The image forming apparatus includes, for example, an optical vortex conversion unit that converts a laser beam into an optical vortex laser beam, and a polarization conversion unit that imparts circular polarization to the optical vortex laser beam, thereby enabling the linear directivity of flying objects of high viscosity or solid light-absorbing material and suppressing the scattering of the light-absorbing material.

[0026] <<Other components>> Other components are not particularly limited and can be selected as appropriate depending on the purpose. Examples include beam diameter changing members, beam wavelength changing elements, and output adjustment units.

[0027] —Beam diameter changing component— There are no particular restrictions on the beam diameter changing member as long as it can change the beam diameter of the laser beam or optical vortex laser beam, and it can be appropriately selected according to the purpose, for example, a focusing lens. There are no particular restrictions on the beam diameter (irradiation diameter) of the optical vortex laser beam, and it can be appropriately selected according to the purpose, but 100 μm or less is preferred. An irradiation diameter of 100 μm or less of the optical vortex laser beam is preferable because it makes it easier to form high-resolution images. The beam diameter can be changed, for example, by adjusting the laser spot diameter and focusing lens. Furthermore, when the light-absorbing material is a dispersion, the beam diameter is preferably greater than or equal to the maximum value of the volume-average particle size of the light-absorbing material, and more preferably three times the maximum value of the dispersion. A beam diameter within a more preferable range is advantageous because it allows the light-absorbing material to fly stably.

[0028] —Beam wavelength changing element— As for the beam wavelength changing element, there are no particular restrictions as long as it can change the wavelength of the laser beam or optical vortex laser beam to a wavelength that can be absorbed by the light-absorbing material and can be transmitted through the substrate described later, and it can be appropriately selected according to the purpose. Examples of beam wavelength changing elements include KTP crystals, BBO crystals, LBO crystals, and CLBO crystals.

[0029] —Output Adjustment Section— The output adjustment unit is not particularly limited as long as it can adjust the laser beam or optical vortex laser beam to an appropriate output value, and can be appropriately selected depending on the purpose. Examples include glass.

[0030] The output value of the optical vortex laser beam irradiated onto the light-absorbing material is not particularly limited, as long as it can produce a liquid column that rotates around the central axis of the irradiation diameter with respect to the irradiation direction and converges to a diameter smaller than the irradiation diameter, or a state in which a portion is separated and liquid droplets are formed. It can be appropriately selected according to the purpose. In the following, "output value" may also be referred to as "irradiation energy". The irradiation energy of the optical vortex laser beam varies depending on the viscosity and film thickness of the light-absorbing material, so it is preferable to adjust it as appropriate. Specifically, it is more preferable to have an irradiation energy of 100 μJ / dot or less, and even more preferable to have an irradiation energy of 60 μJ / dot or less. An irradiation energy of 60 μJ / dot or less of the optical vortex laser beam is advantageous because it makes it easier to create a state in which a liquid column can be formed that rotates around the central axis of the irradiation diameter with respect to the irradiation direction and converges to a diameter smaller than the irradiation diameter, or a state in which a part of it can be separated to form droplets.

[0031] <Transfer method> The transfer method involves bringing a liquid column or droplet, with a diameter smaller than the irradiation diameter of the optical vortex laser beam, generated from a light-absorbing material into contact with the transfer medium and transferring the image. There are no particular restrictions on the transfer means, and they can be appropriately selected depending on the purpose. For example, a means that includes a mechanism for bringing a liquid column or droplet generated from a light-absorbing material into contact with the transfer medium can be used. Specifically, the transfer means may include, for example, a mechanism for adjusting the gap between the object to be attached and the light-absorbing material, or a mechanism for transporting the object to be attached.

[0032] <<Transfer medium>> The transfer medium (object to which the material is attached) is not particularly limited as long as it can come into contact with the liquid column or droplet generated from the light-absorbing material, and can be appropriately selected according to the purpose. Examples include recording media and intermediate transfer belts used in image forming apparatuses.

[0033] <Other means> Other means include, for example, a light-absorbing material supply means, a beam scanning means, a means for transporting the object to be attached, a fixing means, and a control means. Alternatively, the light-absorbing material flight means, substrate, light-absorbing material supply means, and beam scanning means may be treated as an integrated light-absorbing material flight unit. Other processes include, for example, a light-absorbing material supply process, a beam scanning process, a material transport process, a fixing process, and a control process.

[0034] The means for supplying the light-absorbing material is not particularly limited as long as it can supply the light-absorbing material along the optical path of the optical vortex laser beam between the light-absorbing material flight means and the object to be attached, and can be appropriately selected according to the purpose. As an example of the means for supplying the light-absorbing material, the light-absorbing material may be supplied via a cylindrical substrate placed on the optical path. Specifically, when the light-absorbing material is a liquid and is supplied to a substrate, it is preferable to provide a supply roller and a regulating blade as the light-absorbing material supply means, because this allows the light-absorbing material to be supplied to the surface of the substrate with a constant average thickness in a very simple configuration. In this case, the supply roller has its surface partially immersed in a storage tank that stores the light-absorbing material, and supplies the light-absorbing material by rotating while supporting it on its surface and contacting the substrate. The regulating blade is positioned downstream of the storage tank in the direction of rotation of the supply roller, and regulates the light-absorbing material supported by the supply roller to make the average thickness uniform and stabilize the amount of light-absorbing material that is released. By making the average thickness very thin, the amount of light-absorbing material released can be reduced, so that the light-absorbing material can adhere to the substrate as tiny dots with suppressed scattering, and dot gain, which causes the halftone dots to thicken, can be suppressed. The regulating blade may also be positioned downstream of the supply roller in the direction of rotation of the substrate.

[0035] Furthermore, when the light-absorbing material has high viscosity, the material of the supply roller is preferably one that has at least an elastic surface to ensure reliable contact with the substrate. When the light-absorbing material has relatively low viscosity, examples of supply rollers include gravure rolls, microgravure rolls, and forward rolls, which are used in precision wet coating.

[0036] Furthermore, as a light-absorbing material supply means without a supply roller, a layer of light-absorbing material may be formed on the surface of the substrate by directly contacting the substrate with the light-absorbing material in the storage tank and then scraping off excess light-absorbing material with a wire bar or the like. The storage tank may be provided separately from the light-absorbing material supply means, and the light-absorbing material may be supplied to the light-absorbing material supply means by a hose or the like. The light-absorbing material supply process is not particularly limited as long as it is a process of supplying the light-absorbing material on the optical path of the optical vortex laser beam between the light-absorbing material flight means and the object to be attached, and can be appropriately selected according to the purpose. For example, it can be suitably carried out using a light-absorbing material supply means.

[0037] The beam scanning means is not particularly limited as long as it can scan the optical vortex laser beam against the light-absorbing material, and can be appropriately selected according to the purpose. For example, the beam scanning means may include a reflector that reflects the optical vortex laser beam irradiated from the light-absorbing material flight means towards the light-absorbing material, and a reflector drive unit that changes the angle and position of the reflector to scan the optical vortex laser beam against the light-absorbing material. The beam scanning process is not particularly limited as long as it involves scanning an optical vortex laser beam across an optical absorbing material, and can be appropriately selected according to the purpose. For example, it can be suitably carried out using a beam scanning means.

[0038] As for the means of conveying the object to be attached, there are no particular restrictions as long as it can convey the object to be attached, and it can be appropriately selected according to the purpose. For example, a pair of conveying rollers can be used. The process for conveying the object to be attached is not particularly limited as long as it involves conveying the object to be attached, and can be appropriately selected according to the purpose. For example, it can be suitably carried out using a means for conveying the object to be attached.

[0039] As for the fixing method, there are no particular restrictions as long as it can fix the light-absorbing material attached to the object to be attached, and it can be appropriately selected according to the purpose. For example, a thermocompression method using a heating and pressing member can be used. There are no particular restrictions on the heating and pressing components, and they can be appropriately selected according to the purpose. Examples include heating rollers, pressure rollers, and combinations of heating rollers and pressure rollers. Other heating and pressing components include combinations of these with fixing belts, and those in which the heating rollers are replaced with heating blocks.

[0040] As a pressure roller, one in which the pressure surface moves at the same speed as the object being transported by the object transport means is preferable in that it suppresses image degradation due to friction. Among these, one in which an elastic layer is formed near the surface is more preferable in that it is easier to apply contact pressure to the object being transported. Furthermore, a pressure roller in which a water-repellent surface layer is formed on the outermost surface using a low surface energy material such as a silicone-based water-repellent material or a fluorine compound is particularly preferable in that it suppresses image distortion caused by the adhesion of light-absorbing material to the surface. Examples of water-repellent surface layers made of silicone-based water-repellent materials include films of silicone-based mold release agents, baked films of silicone oil or various modified silicone oils, films of silicone varnish, films of silicone rubber, and films made of composites of silicone rubber and various metals, rubbers, plastics, ceramics, etc. Examples of water-repellent surface layers made of fluorine compounds include fluororesin coatings, organic fluorine compound coatings, baked or adsorbed fluorine oil coatings, fluororubber coatings, or coatings made of composite materials of fluororubber and various metals, rubbers, plastics, ceramics, etc.

[0041] There are no particular restrictions on the heating temperature of the heating roller, and it can be appropriately selected depending on the purpose, but a temperature of 80°C to 200°C is preferred.

[0042] The fixing belt is not particularly limited as long as it has heat resistance and high mechanical strength, and can be appropriately selected according to the purpose. Examples include films such as polyimide, PET, and PEN. Furthermore, it is preferable to use the same material as the outermost surface of the pressure roller for the fixing belt, in order to suppress image distortion caused by the adhesion of light-absorbing material to the surface. Since the fixing belt can be made thin, the energy required to heat the belt itself can be reduced, so it can be used immediately after the power is turned on. The temperature and pressure at this time vary depending on the composition of the light-absorbing material to be fixed, but a temperature of 200°C or less is preferable from the viewpoint of energy saving, and a pressure of 1 kg / cm or less is preferable from the viewpoint of the rigidity of the device.

[0043] When using two or more types of light-absorbing materials, each color of light-absorbing material may be fixed after it adheres to the substrate, or all types of light-absorbing materials may be attached to the substrate and fixed in a laminated state. Furthermore, if the light-absorbing material is very viscous and drying is slow, making it difficult to improve the adhesion rate to the substrate, the substrate may be further heated to accelerate drying. Furthermore, if the light-absorbing material penetrates and wets the substrate slowly, and the attached light-absorbing material is dried before it has sufficiently smoothed, the surface of the substrate to which the light-absorbing material is attached may become rough, resulting in a lack of surface gloss. To obtain surface gloss, a fixing method that uses pressure to fix the material may be used to fix the light-absorbing material attached to the substrate by crushing and pressing it into the substrate, thereby reducing the surface roughness of the substrate. Fixing means are necessary to fix the light-absorbing material to the object to be attached, especially when using a solid light-absorbing material formed by compressing powder. If necessary, a known light-fixing device may be used in conjunction with the fixing means. The fixing process is not particularly limited as long as it is a process of fixing the light-absorbing material attached to the object to be attached to the object, and can be appropriately selected according to the purpose. For example, it can be suitably carried out using a fixing means.

[0044] As long as the control means can control the movement of each means, there are no particular restrictions, and they can be appropriately selected according to the purpose. Examples include devices such as sequencers and computers. The control process is a process that controls each process, and can be suitably carried out by control means.

[0045] <Light-absorbing material> The light-absorbing material contains a light-absorbing substance and, as necessary, other substances as appropriately selected. The light-absorbing material preferably has an absorbance greater than 1 for the wavelength of the optical vortex laser beam, and more preferably greater than 2. A light-absorbing material with an absorbance greater than 2 for the wavelength of the optical vortex laser beam is advantageous because it can improve energy efficiency.

[0046] <<Light-absorbing material>> There are no particular restrictions on the light-absorbing material as long as it absorbs light of a specific wavelength, and it can be appropriately selected according to the purpose. Examples include pigments, dyes, and other colorants.

[0047] There are no particular limitations on the light absorption performance of a light-absorbing material at a given wavelength, and it can be appropriately selected according to the purpose. However, the transmittance (absorbance) in a coated film state with a film thickness of 3 μm is preferably 80% or less (0.1 or more), more preferably 50% or less (0.3 or more), and particularly preferably 30% or less (0.5 or more). Furthermore, in a coating film formed with a light-absorbing material having light-absorbing properties, the transmittance (absorbance) in the film thickness of the light-absorbing material is preferably 10% or less (1 or more), more preferably 1% or less (2 or more), even more preferably 0.1% or less (3 or more), and particularly preferably 0.01% or less (4 or more). When the transmittance is within the preferred range, the energy of the optical vortex laser beam absorbed by the substrate is less likely to be converted into heat, which is advantageous because it reduces the likelihood of changes such as drying or melting occurring in the light-absorbing material. Moreover, when the transmittance is within the preferred range, the energy supplied to the light-absorbing material does not decrease easily, which is advantageous because it reduces the likelihood of variations in the adhesion position. The transmittance (absorbance) can be measured using, for example, a spectrophotometer (Shimadzu Corporation, UV3600).

[0048] There are no particular restrictions on the form, size, or material of light-absorbing materials, and they can be appropriately selected according to the purpose. Examples of light-absorbing materials include liquids, solids, and powders. In particular, the ability to launch highly viscous materials or solids is an advantage that cannot be achieved with conventional inkjet recording methods. Furthermore, if the light-absorbing material is a solid or powder, it is preferable that the light-absorbing material is viscous when irradiated with an optical vortex laser beam. Specifically, if it is desired that the solid or powder material be ejected, it is preferable, for example, to heat it to a melted state before irradiating it with an optical vortex laser beam to create a viscous form.

[0049] There are no particular restrictions on the liquid light absorber, and it can be appropriately selected according to the purpose. Examples include inks containing pigments and solvents, and conductive pastes containing conductors and solvents. When an optical vortex laser beam is irradiated onto an ink containing a solvent, if the solvent does not absorb light, the energy of the optical vortex laser beam is transferred to a light-absorbing component other than the solvent, and the solvent is ejected along with that component. There are no particular restrictions on the viscosity of the liquid light absorber, and it can be appropriately selected depending on the purpose, but a viscosity of 1 Pa·s or higher is preferred, and a viscosity of 1 Pa·s or higher and 20 Pa·s or lower is more preferred. Viscosity can be measured at 25°C using, for example, a rotational viscometer (VISCOMATE VM-150III, manufactured by Toki Sangyo Co., Ltd.).

[0050] The conductive paste is not particularly limited as long as it contains a conductive material, and can be appropriately selected depending on the purpose. Examples include conductive pastes that are known or conventionally used in the manufacturing of circuit boards. There are no particular restrictions on the conductor, and it can be appropriately selected depending on the purpose. Examples include conductive inorganic particles such as silver, gold, copper, nickel, ITO, carbon, and carbon nanotubes; and conductive organic polymer particles such as polyaniline, polythiophene (e.g., poly(ethylenedioxythiophene)), polyacetylene, and polypyrrole. These may be used individually or in combination of two or more. There are no particular restrictions on the volume resistivity of the conductive paste, and it can be appropriately selected depending on the purpose, but 10 is suitable for use as a normal electrode. 3 A value of Ω·cm or less is preferable.

[0051] Examples of powder light-absorbing materials include toner containing pigment and binder resin, and metal nanoparticles such as solder balls. In this case, when an optical vortex laser beam is irradiated, the pigment is imbued with the energy of the optical vortex laser beam, and the binder resin, along with the pigment, flies as toner. Note that the powder light-absorbing material may consist of pigment alone.

[0052] There are no particular restrictions on the solid light-absorbing material, and it can be appropriately selected according to the purpose. Examples include thin metal films formed by sputtering or vapor deposition, and compressed powders such as dispersions.

[0053] There are no particular restrictions on the metal thin film, and it can be appropriately selected according to the purpose. Examples of metals include common metals that can be vapor-deposited or sputtered, such as silver, gold, aluminum, platinum, and copper. These may be used individually or in combination of two or more. One method for forming an image pattern by launching a thin metal film is to first create a thin metal film on a substrate such as glass or film, and then irradiate the thin metal film with an optical vortex laser beam to launch it and form an image pattern. Another method is to form an image pattern by launching non-image areas.

[0054] The compressed powder is preferably in the form of layers with a predetermined average thickness, and the layered solid may be supported on the surface of the substrate.

[0055] There are no particular restrictions on the size of the light-absorbing material; it can be selected appropriately depending on the purpose. There are no particular restrictions on the average thickness of the light-absorbing material, and it can be appropriately selected depending on the purpose, but it is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 10 μm to 50 μm. By setting the average thickness of the light-absorbing material to the above preferred range, scattering of the light-absorbing material when irradiated with an optical vortex laser beam can be suppressed. When the average thickness of the light-absorbing material is within a desirable range, supplying the material in layers ensures the strength of the layers even during continuous flight, which is advantageous in that it enables a stable supply. Furthermore, because the energy of the optical vortex laser beam does not become excessively high, degradation and decomposition are less likely to occur, especially when the light-absorbing material is organic. Furthermore, depending on the application method, it may be possible to supply the material as a layer that maintains a certain pattern.

[0056] There are no particular restrictions on the method for measuring the average thickness, and it can be appropriately selected depending on the purpose. For example, one method involves selecting several arbitrary points on the light-absorbing material and calculating the average thickness of those points. Preferably, the average thickness of 5 points is preferred, the average thickness of 10 points is more preferred, and the average thickness of 20 points is particularly preferred. There are no particular restrictions on the instruments used to measure average thickness; they can be appropriately selected according to the purpose. Examples include non-contact or contact methods such as laser displacement meters and micrometers.

[0057] There are no particular restrictions on the material of the light-absorbing material, and it can be appropriately selected according to the purpose. For example, when forming images, it may be a coloring agent such as toner, and when manufacturing three-dimensional objects, it may be a three-dimensional molding agent as described later.

[0058] -Colorants- Similar to light-absorbing materials, there are no particular restrictions on the shape, material, etc., of colorants, and they can be appropriately selected according to the purpose. The differences when using light-absorbing materials as colorants are explained below.

[0059] There are no particular restrictions on the liquid colorant, and it can be appropriately selected depending on the purpose. For example, water-based inks, in which colorants such as dyes, pigments, coloring particles, or coloring oil droplets are dispersed in water as a solvent, can be used. In addition to water-based inks, colorants containing relatively low-boiling-point liquids as solvents, such as hydrocarbon-based organic solvents or various alcohols, can also be used. Among these, water-based inks are preferred in terms of the safety of volatile components and the risk of explosion.

[0060] Furthermore, since the image forming apparatus can form images using process inks for offset printing that use plates, JAPAN COLOR compatible inks, and spot color inks, it is possible to easily reproduce digital images that match the colors used in offset printing without the need for plates. Furthermore, since image formation is possible even with UV-curing ink, curing by irradiating with ultraviolet light during the fixing process prevents blocking, where overlapping recording media stick together, and simplifies the drying process.

[0061] Examples of colorants include organic pigments, inorganic pigments, and dyes. These may be used individually or in combination of two or more.

[0062] Examples of organic pigments include dioxazine violet, quinacridone violet, copper phthalocyanine blue, phthalocyanine green, sap green, monoazo yellow, disazo yellow, polyazo yellow, benzimidazolon yellow, isoindolinone yellow, first yellow, chromophthal yellow, nickelazo yellow, azomethine yellow, benzimidazolon orange, alizarin red, quinacridone red, naphthol red, monoazo red, polyazo red, perylene red, anthraquinonyl red, diketopyrrolopyrrole red, diketopyrrolopyrrole orange, benzimidazolon brown, sepia, and aniline black. Examples of metal lake pigments among organic pigments include rhodamine lake, quinoline yellow lake, and brilliant blue lake.

[0063] Examples of inorganic pigments include cobalt blue, cerulean blue, cobalt violet, cobalt green, zinc white, titanium white, titanium yellow, chromium titanium yellow, light red, chromium oxide green, Mars black, viridian, yellow ochre, alumina white, cadmium yellow, cadmium red, vermilion, lithopone, ultramarine, talc, white carbon, clay, mineral violet, rose cobalt violet, silver white, calcium carbonate, and magnesium carbonate. Examples include zinc oxide, zinc sulfide, strontium sulfide, strontium aluminate, brass, gold powder, bronze powder, aluminum powder, brass pigment, ivory black, peach black, lamp black, carbon black, Prussian blue, aureolin, titanium mica, yellow ochre, terre verte, raw sienna, raw umber, Cassel earth, chalk, gypsum, burnt sienna, burnt umber, lapis lazuli, azurite, malachite, orpiment, cinnabar, coral powder, white pigment, red iron oxide, ultramarine, dark blue, fish scale foil, and iron oxide treated pearl.

[0064] Among these, carbon black is preferred as a black pigment in terms of hue and image preservation properties. As a cyan pigment, CI Pigment Blue 15:3, which is copper phthalocyanine blue, is preferred from the viewpoint of hue and image preservation.

[0065] Preferred magenta pigments include CI Pigment Red 122 (quinacridone red), CI Pigment Red 269 (naphthol red), and CI Pigment Red 81:4 (rhodamine lake). These may be used individually or in combination of two or more. Among these, a mixture of CI Pigment Red 122 and CI Pigment Red 269 is more preferred in terms of hue and image preservation. A mixture of CI Pigment Red 122 (PR122) and CI Pigment Red 269 (PR269) with a PR122:PR269 ratio of 5:95 to 80:20 is particularly preferred. When PR122:PR269 is within this particularly preferred range, the hue does not deviate from the magenta color.

[0066] Preferred yellow pigments include CI Pigment Yellow 74 (monoazo yellow), CI Pigment Yellow 155 (disazo yellow), CI Pigment Yellow 180 (benzimidazolone yellow), and CI Pigment Yellow 185 (isoindoline yellow). Among these, CI Pigment Yellow 185 is more preferred in terms of hue and image preservation. These may be used individually or in combination of two or more.

[0067] When using a light-absorbing material as a process color ink, it is preferable to use a set of four inks.

[0068] Inorganic pigments often consist of particles with a volume-average particle size exceeding 10 μm. When using inorganic pigments with a volume-average particle size of 10 μm or more as a colorant, it is preferable that the colorant be liquid. A liquid colorant has the advantage of being able to maintain a stable state without using forces other than non-electrostatic adhesion forces such as electrostatic force. Furthermore, compared to inkjet recording methods, where nozzle clogging and ink sedimentation are likely to occur and a stable continuous printing process is difficult to achieve, the image forming method of the present invention is extremely effective. Moreover, compared to electrophotography methods, where a sufficient amount of charge cannot be obtained when the surface area of ​​the colorant particles is small, making it impossible to establish a stable continuous printing process, the image forming method of the present invention is also extremely effective.

[0069] Examples of dyes include monoazo dyes, polyazo dyes, metal complex azo dyes, pyrazolone azo dyes, stilbene azo dyes, thiazole azo dyes, anthraquinone derivatives, anthrone derivatives, indigo derivatives, thioindigo derivatives, phthalocyanine dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, acridine dyes, azine dyes, oxazine dyes, thiazine dyes, polymethine dyes, azomethine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, and perinone dyes.

[0070] There are no particular restrictions on the viscosity of the coloring agent; it can be appropriately selected depending on the purpose. When using a liquid colorant that penetrates the recording medium, the colorant adhering to the recording medium may cause feathering or bleeding. However, when using a high-viscosity colorant that can be handled by the image forming apparatus of the present invention, the drying rate is faster than the penetration rate into the recording medium. Therefore, the reduction in bleeding, in particular, improves color development and sharpens the edges, enabling the formation of high-quality images. Furthermore, even when performing gradation expression by layering colorants, bleeding due to an increase in the amount of colorant can be reduced. Furthermore, since this image formation method involves spraying and attaching a liquid colorant, it can record well even if minute irregularities exist on the recording medium, compared to, for example, the so-called thermal transfer method which melts and transfers the colorant from a film-like colorant carrier using heat.

[0071] There are no particular restrictions on the average thickness of the colorant, and it can be appropriately selected depending on the purpose, but 100 μm or less is preferred. An average thickness of 100 μm or less is advantageous because it reduces the energy required to propel the colorant, thus reducing the durability of the colorant carrier and preventing decomposition of the composition if the colorant is organic. The preferred range for the average thickness varies depending on the recording medium, purpose, etc.

[0072] For example, when using coated paper or smooth film, which are commonly used in offset printing, as the recording medium, the average thickness of the colorant is preferably between 0.5 μm and 5 μm. When the average thickness is within this preferred range, color differences due to minute differences in the average thickness of the recording medium become difficult for the human eye to distinguish, making it easier to produce images with high saturation even on coated paper. Furthermore, it is advantageous in that dot gain of halftones does not become significant, making it easier to express sharp images.

[0073] Furthermore, when using recording media with a surface roughness greater than that of coated paper or film, such as high-quality paper used in offices, the average thickness of the colorant is preferably 3 μm to 10 μm. When the average thickness is within this preferred range, it is less affected by the surface roughness of the recording media, making it easier to obtain good image quality. In particular, when expressing full-color images with process colorant, the step-like appearance is less likely to be noticeable even when multiple layers of colorant are stacked.

[0074] Furthermore, for example, when used in textile printing to dye fabrics and fibers, an average thickness of 5 μm or more of the colorant is often required to adhere the colorant to the recording medium, such as cotton, silk, or synthetic fibers. This is because the fibers are thicker than those of paper, often requiring a larger amount of colorant.

[0075] <Base material> There are no particular restrictions on the shape, structure, size, or material of the substrate, and it can be appropriately selected according to the purpose. The shape of the substrate is not particularly limited as long as it can support a light-absorbing material on its surface and allow irradiation of a vortex laser beam from the back surface; it can be appropriately selected according to the purpose. Examples of substrate shapes include flat plates, cylindrical shapes such as circles or ellipses, surfaces cut from a part of a cylinder, and endless belt shapes. Among these, it is preferable that the substrate be cylindrical and have a light-absorbing material supply means that supplies the light-absorbing material to the surface of the substrate as it rotates in the circumferential direction. When the light-absorbing material is supported on the surface of a cylindrical substrate, it can be supplied regardless of the dimensions of the object to be attached in the circumferential direction. In this case, a light-absorbing material launching means is arranged inside the cylinder, allowing irradiation of a vortex laser beam from the inside toward the outer circumference, and continuous irradiation is possible as the substrate rotates in the circumferential direction. Examples of flat substrate shapes include glass slides.

[0076] There are no particular restrictions on the structure of the base material, and it can be appropriately selected according to the purpose.

[0077] There are no particular restrictions on the size of the base material, and it can be appropriately selected according to the purpose, but it is preferable to use dimensions that match the width of the object to be attached.

[0078] There are no particular restrictions on the material of the substrate as long as it transmits light, and it can be appropriately selected according to the purpose. Among light-transmitting materials, inorganic materials such as various types of glass mainly composed of silicon dioxide, transparent heat-resistant plastics, and organic materials such as elastomers are preferred in terms of transmittance and heat resistance.

[0079] There are no particular restrictions on the surface roughness Ra of the substrate, and it can be appropriately selected according to the purpose. However, it is preferable that both the front and back surfaces have a surface roughness of 1 μm or less, in order to suppress the refraction and scattering of the optical vortex laser beam and not reduce the energy imparted to the light-absorbing material. Furthermore, having a surface roughness Ra within a preferred range is advantageous because it can suppress variations in the average thickness of the light-absorbing material attached to the object, allowing for the attachment of the desired amount of light-absorbing material. Surface roughness Ra can be measured according to JIS B0601, for example, using a confocal laser microscope (manufactured by Keyence Corporation) or a stylus-type surface profile analyzer (Dektak150, manufactured by Bruker AXS Corporation).

[0080] <Subjects> There are no particular restrictions on the object to be attached (transfer medium), and it can be appropriately selected according to the purpose. Examples include a recording medium for forming an image, and a support substrate for forming a three-dimensional object.

[0081] -Recording medium- There are no particular restrictions on the recording medium, and it can be appropriately selected according to the purpose. Examples include coated paper, fine paper, film, cloth, and textiles.

[0082] The gap between the object to be attached and the light-absorbing material is not particularly limited as long as the object and the light-absorbing material do not come into contact, and can be appropriately selected according to the purpose. However, a gap of 0.05 mm to 5 mm is preferred, 0.10 mm to 1 mm is more preferred, and 0.10 mm to 0.50 mm is particularly preferred. Having a gap between the object and the light-absorbing material within a preferred range is advantageous because it reduces the likelihood of a decrease in the accuracy of the attachment position of the light-absorbing material to the object. Furthermore, by preventing contact between the object and the light-absorbing material, it becomes possible to attach the light-absorbing material to the object regardless of the composition of the light-absorbing material and the object to be attached. Furthermore, it is preferable that the gap be kept constant by means of a position control mechanism that maintains a constant position of the object to be attached. In this case, it is important to arrange each part considering the positional fluctuations of the light-absorbing material and the object to be attached, as well as variations in average thickness.

[0083] Furthermore, there are no particular restrictions on the average diameter (average dot diameter) of the light-absorbing material after transfer (adhesion) on the transfer medium (object to which it is attached), and it can be appropriately selected according to the purpose. However, it is preferable to set it to 100 μm or less in order to further improve the resolution of the formed image or three-dimensional object. In the present invention, the diameter of the flying droplet is smaller than the diameter of the irradiated optical vortex laser beam, but the diameter of the dot formed on the transfer medium changes due to the impact at the time of droplet placement and the relationship with the surface tension of the transfer medium surface. Furthermore, the average dot diameter can be determined, for example, by acquiring a dot image of a light-absorbing material using a microscope, detecting the dot area from the image brightness information, calculating the area of ​​each dot from the number of pixels in the detected dot area, converting it to a circle, taking the diameter as the dot diameter, and averaging these.

[0084] Furthermore, the variation in the diameter (dot diameter) of the light-absorbing material after transfer (adhesion) on the transfer medium (object to which the material is attached) is preferably 10% or less, and more preferably 6% or less. By setting the variation in the diameter of the light-absorbing material after transfer on the transfer medium to the above preferred range, the accuracy of forming images and three-dimensional objects can be further improved. Furthermore, the variation in the diameter of the light-absorbing material after transfer in the transfer medium can be determined, for example, by acquiring a dot image of the light-absorbing material with a microscope, detecting the dot area from the image brightness information, calculating the area of ​​each dot from the number of pixels in the detected dot area, taking the diameter when converted to a circle as the dot diameter, and calculating it from the average particle size and standard deviation of the particle size distribution of each dot.

[0085] In addition, the variation in the position (dot position) of the light-absorbing material after transfer (adhesion) on the transfer medium (object to which the material is attached) is preferably 10 μm or less, and more preferably 5 μm or less. By setting the variation in the position of the light-absorbing material after transfer on the transfer medium to the above preferred range, the accuracy when forming images or three-dimensional objects can be further improved. For example, when attaching dots of light-absorbing material in a row, the variation in the position of the light-absorbing material in a direction perpendicular to the row of dots can be used as the value of the variation in the position of the light-absorbing material. For example, this can be determined by acquiring a dot image of a light-absorbing material using a microscope, detecting the dot regions from the image brightness information, calculating the centroid coordinates of each detected dot region, and then calculating the deviation of each centroid from an approximate straight line using the least squares method.

[0086] Furthermore, the light-absorbing material flight means, the light-absorbing material supply means, and the beam scanning means may be treated as a single colorant flight unit. For example, four colorant launching units may be installed in the image forming apparatus to launch process colorants of yellow, magenta, cyan, and black. There are no particular restrictions on the number of colorants; they can be appropriately selected according to the purpose, and the number of colorant launching units may be increased or decreased as needed. Furthermore, by placing a colorant launching unit with a white colorant upstream of the colorant launching unit with process colorants in the transport direction of the recording medium, it is possible to create a white opacity layer, thereby forming an image with excellent color reproduction on a transparent recording medium. However, especially for yellow, white, and transparent colorants, it may be necessary to appropriately select the laser light source, such as a blue laser beam or an ultraviolet laser beam, so that the transmittance (absorbance) of light at the wavelength of the optical vortex laser beam is appropriate.

[0087] Furthermore, since high-viscosity colorants can be used in the image forming apparatus, even when different colored colorants are sequentially layered on the recording medium to form an image, bleeding, where the colorants bleed and mix together, can be suppressed, thus enabling the acquisition of high-quality color images.

[0088] For the purpose of miniaturizing the image forming apparatus, a single colorant flight unit may be provided, and the colorant itself supplied to the supply roller and colorant carrier may be switched to form images with multiple colors.

[0089] Furthermore, the image forming apparatus of the present invention can also be applied to a manufacturing apparatus for three-dimensional objects as follows.

[0090] (Manufacturing equipment for three-dimensional objects) The apparatus for manufacturing three-dimensional objects preferably includes at least a three-dimensional molding agent launching device and a three-dimensional molding agent curing means, and may further include other means as needed. The three-dimensional molding agent launching device is an image forming apparatus in which the light-absorbing material is the three-dimensional molding agent, and the three-dimensional molding agent is launched by the three-dimensional molding agent launching means.

[0091] <Method for launching three-dimensional molding material> The three-dimensional molding agent launching means is the same as the light-absorbing material launching means described above, except that the light-absorbing material is the three-dimensional molding agent and the object to be attached is the object support substrate, so its explanation will be omitted. The three-dimensional molding agent launching means stacks the three-dimensional molding agent in layers on the object support substrate and attaches it three-dimensionally.

[0092] <Method for curing three-dimensional molding agent> There are no particular restrictions on the curing method for the 3D modeling agent, and it can be appropriately selected depending on the purpose. For example, if the 3D modeling agent is an ultraviolet-curable material, an ultraviolet irradiator can be used. There are no particular restrictions on the curing process for the three-dimensional molding agent, and it can be appropriately selected depending on the purpose. For example, if the three-dimensional molding agent is an ultraviolet-curable material, an ultraviolet irradiation process can be used, and this can be suitably carried out using a three-dimensional molding agent curing means.

[0093] <Other means> Other means include, for example, a means for supplying a three-dimensional molding agent, a means for scanning the three-dimensional molding head unit, a means for adjusting the substrate position, and a control means.

[0094] <<Means for supplying three-dimensional molding agent>> The means for supplying the three-dimensional molding agent is the same as the aforementioned means for supplying the light-absorbing material, except that the light-absorbing material is the three-dimensional molding agent and the object to which it is attached is the substrate supporting the molded object; therefore, its explanation will be omitted.

[0095] <<3D Modeling Head Unit Scanning Means>> There are no particular restrictions on the scanning means for the 3D printing head unit, and it can be appropriately selected according to the purpose. For example, a 3D printing head unit that integrates a light absorber flight unit and an ultraviolet light absorber flight means may be scanned on the object support substrate in the width direction (X-axis) of the device. The 3D printing head unit may, for example, cure an ultraviolet-curable 3D printing agent attached by the light absorber flight unit using the ultraviolet light absorber flight means. Furthermore, multiple 3D printing head units may be provided.

[0096] <<Board position adjustment means>> There are no particular restrictions on the substrate position adjustment means, and they can be appropriately selected according to the purpose. For example, a base (stage) that can adjust the position of the object support substrate in the depth direction (Y-axis) and height direction (Z-axis) of the device may be used.

[0097] <<Control means>> The control means are the same as those for the image forming apparatus described above, so their explanation will be omitted.

[0098] <3D modeling agent> Similar to light-absorbing materials, there are no particular restrictions on the shape, material, etc., of a three-dimensional molding agent, and it can be appropriately selected according to the purpose. The differences when using a light-absorbing material as a three-dimensional molding agent are explained below.

[0099] There are no particular restrictions on the average thickness of the 3D printing agent; it can be appropriately selected depending on the purpose and varies depending on the required precision, but a range of 5 μm to 500 μm is preferable. Having an average thickness within this preferable range is advantageous in terms of the accuracy, texture, smoothness, and manufacturing time of the 3D printed object. Furthermore, an average thickness of 5 μm to 100 μm is more preferable. Having an average thickness within this more preferable range is advantageous because it allows for lower energy levels of the optical vortex laser beam, thereby suppressing degradation of the 3D printing agent.

[0100] The three-dimensional molding agent contains at least a curable material, and may further contain other components as needed.

[0101] <<Curable material>> As curable materials, there are no particular limitations as long as they are compounds that undergo polymerization reactions and harden upon irradiation with active energy rays (ultraviolet rays, electron beams, etc.) or heating, and can be appropriately selected according to the purpose. Examples include active energy ray curable compounds and thermosetting compounds. Among these, materials that are liquid at room temperature are preferred. Active energy ray curable compounds are relatively low-viscosity monomers that have radically polymerizable unsaturated double bonds in their molecular structure, and include monofunctional monomers and polyfunctional monomers.

[0102] <<Other ingredients>> Other components are not particularly limited and can be selected as appropriate depending on the purpose. Examples include water, organic solvents, photopolymerization initiators, surfactants, colorants, stabilizers, water-soluble resins, low-boiling alcohols, surface treatment agents, viscosity modifiers, adhesion promoters, antioxidants, anti-aging agents, crosslinking accelerators, UV absorbers, plasticizers, preservatives, and dispersants.

[0103] <3D modeling agent carrier> The material carrier is the same as the substrate described above, except that the light-absorbing material is used as the material carrier, so its explanation will be omitted.

[0104] <Object support substrate> There are no particular restrictions on the substrate used to support the fabricated object; it can be appropriately selected according to the purpose. For example, the position of the Y-axis and Z-axis may be adjusted by substrate position adjustment means.

[0105] The gap between the support substrate for the molded object and the mold material carrier is the same as the gap between the object to be attached and the base material, so its explanation is omitted.

[0106] Next, an example of an image forming apparatus according to the present invention will be described with reference to the drawings. The number, position, shape, etc. of the following components are not limited to this embodiment, and can be set to a number, position, shape, etc. that is preferable for carrying out the present invention.

[0107] Figure 5A is an explanatory diagram showing an example of the image forming apparatus of the present invention. In Figure 5A, the image forming apparatus 300 comprises a light-absorbing material launching means 1, a light-absorbing material 20 that absorbs light, an object to be attached to 30, and a substrate 40. The image forming apparatus 300 is a device that irradiates the light-absorbing material 20, which is supported on the substrate 40, with an optical vortex laser beam 12 of light using the light-absorbing material launching means 1, causing the light-absorbing material 20 to fly in the irradiation direction due to the energy of the optical vortex laser beam 12, and to attach to the object to be attached to 30.

[0108] The light-absorbing material flight means 1 includes a laser light source 2, beam diameter changing members 3 and 7, beam wavelength changing member 4, optical vortex conversion unit 5, and polarization conversion unit 6.

[0109] The laser light source 2 is, for example, a titanium-sapphire laser, which generates a pulsed laser beam 11 and irradiates the beam diameter changing member 3 with it. The beam diameter changing member 3 is, for example, a focusing lens, and is positioned downstream of the laser light source 2 in the optical path of the laser beam 11 generated by the laser light source 2, thereby changing the diameter of the laser beam 11. The beam wavelength changing member 4 is, for example, a KTP crystal and is positioned downstream of the beam diameter changing member 3 in the optical path of the laser beam 11, changing the wavelength of the laser beam 11 to a wavelength that can be absorbed by the light absorbing material 20. The optical vortex conversion unit 5 is, for example, a helical phase plate, and is positioned downstream of the beam wavelength changing member 4 in the optical path of the laser beam 11, converting the laser beam 11 into an optical vortex laser beam 12. The polarization conversion unit 6 is, for example, a quarter-wave plate, which imparts circular polarization to the optical vortex laser beam.

[0110] The light-absorbing material 20 is irradiated with an optical vortex laser beam 12 from the light-absorbing material flight means 1, receives energy within the diameter range of the optical vortex laser beam 12, flies, and adheres to the object to be attached 30. Furthermore, the flying light-absorbing material 20 is twisted and cut while converging near the central axis of the beam diameter due to the forward propulsion provided by the appropriate energy of the optical vortex laser beam 12 and the gyroscopic effect, thereby suppressing scattering to the surroundings and adhering to the object to be attached 30. At this time, the amount of light-absorbing material 20 flying is a portion of the area of ​​the light-absorbing material 20 irradiated by the optical vortex laser beam 12, and can be adjusted by the optical vortex conversion unit 5.

[0111] Figure 5B is an explanatory diagram showing another example of the image forming apparatus of the present invention. In Figure 5B, the image forming apparatus 301 includes a substrate 40 and a beam scanning means 60, in addition to the means of the image forming apparatus 300 shown in Figure 5A. The image forming apparatus 301 scans the optical vortex laser beam 12 generated by the optical absorbing material flight means 1 in a direction perpendicular to the irradiation direction of the optical vortex laser beam 12 using the beam scanning means 60. As a result, the image forming apparatus 301 can irradiate any position on the optical absorbing material 20 supported by the flat substrate 40, and attach the flown optical absorbing material 20 to the object to be attached 30.

[0112] The beam scanning means 60 is positioned downstream of the light-absorbing material flight means 1 in the optical path of the optical vortex laser beam 12 and has a reflector 61. The reflector 61 is moved by the reflector driving means in the scanning direction indicated by arrow S in Figure 5B, and reflects the optical vortex laser beam 12 to any position on the light absorbing material 20. The beam scanning means 60 may, for example, move the light-absorbing material flight means 1 itself or rotate the light-absorbing material flight means 1 to change the irradiation direction of the optical vortex laser beam 12. Alternatively, the beam scanning means 60 may scan the optical vortex laser beam 12 to any position by using a polygon mirror as the reflector 61.

[0113] The substrate 40 is positioned downstream of the beam scanning means 60 in the optical path of the optical vortex laser beam 12 and is used, for example, to coat and fix the light-absorbing material 20 when the light-absorbing material 20 is a high-viscosity liquid. The substrate 40 is light-transmitting and supports the light-absorbing material 20 on its surface, and the light-absorbing material 20 is irradiated from the back surface by the optical vortex laser beam 12. Furthermore, by controlling the average thickness of the light-absorbing material 20 layers to be constant when the light-absorbing material 20 is supported on the substrate 40, the amount of light-absorbing material 20 that flies can be stabilized. The combination of the light-absorbing material flight means 1 and the beam scanning means 60 is referred to as the optical vortex laser beam irradiation unit 100.

[0114] Figure 5C is an explanatory diagram showing another example of the image forming apparatus of the present invention. In Figure 5C, the image forming apparatus 301a has galvanometer scanners (galvanometer mirrors) 62a and 62b as beam scanning means 60 in the image forming apparatus 301 shown in Figure 5B. The galvanometer scanners 62a and 62b are each movable in an independent scanning direction (two dimensions) and can reflect the optical vortex laser beam 12 to any position on the light absorbing material 20. By using galvanometer scanners 62a and 62b as beam scanning means 60, the scanning speed and scanning accuracy of the optical vortex laser beam 12 can be further improved. Furthermore, in the image forming apparatus 301a, it is also preferable to place an fθ lens between the galvanoscanner 62b and the substrate 40, for example.

[0115] Figure 6A is an explanatory diagram showing an example of the image forming apparatus shown in Figure 5B, with the addition of a light-absorbing material supply means and a means for transporting the object to be attached. In Figure 6A, the image forming apparatus 302 has, in addition to the means of the image forming apparatus 301 shown in Figure 5B, a light-absorbing material supply means 50 and a material transport means 70, and the flat base plate 40 is replaced with a cylindrical light-absorbing material carrying roller 41. Furthermore, an optical vortex laser beam irradiation unit 100 is positioned inside the light-absorbing material carrying roller 41, and irradiates the material 30 carried on the outer circumference of the light-absorbing material carrying roller 41 with an optical vortex laser beam 12.

[0116] The light-absorbing material supply means 50 includes a storage tank 51, a supply roller 52, and a regulating blade 53. The storage tank 51 is located near the bottom of the supply roller 52 and stores the light-absorbing material 10. The supply roller 52 is positioned to contact the light-absorbing material-carrying roller 41, and a portion of it is immersed in the light-absorbing material 10 in the storage tank 51. The supply roller 52 rotates in the direction indicated by arrow R2 in Figure 6A, either by a rotational drive means or in accordance with the rotation of the light-absorbing material-carrying roller 41, while adhering the light-absorbing material 10 to its surface. The adhering light-absorbing material 10 is made to a uniform average thickness by the regulating blade 53 and is supplied as a layer by being transferred to the light-absorbing material-carrying roller 41. The light-absorbing material 10 supplied to the surface of the light-absorbing material-carrying roller 41 is continuously supplied to the position where the optical vortex laser beam 12 is irradiated as the light-absorbing material-carrying roller 41 rotates. The regulating blade 53 is positioned upstream of the light-absorbing material-carrying roller 41 in the rotational direction indicated by arrow R2 in the figure, and regulates the light-absorbing material 10 that the supply roller 52 has attached to its surface, thereby making the average thickness of the light-absorbing material 10 supplied to the light-absorbing material-carrying roller 41 uniform.

[0117] The material transport means 70 is positioned near the light-absorbing material carrying roller 41 so that the material to be transported 30 does not come into contact with the light-absorbing material carrying roller 41, and includes a material transport roller 71 and a material transport belt 72 stretched over the material transport roller 71. The material transport means 70 rotates the material transport roller 71 using a rotary drive means, and the material transport belt 72 transports the material to be transported 30 in the transport direction indicated by arrow C in Figure 6A. At this time, the optical vortex laser beam irradiation unit 100 irradiates the optical vortex laser beam 12 from the inside of the light-absorbing material carrying roller 41 according to the image information, and adheres the light-absorbing material 20 to the object to be attached 30. By performing this adhesion operation, which involves adhering the light-absorbing material 20 to the object to be attached 30 while moving the object to be attached 30 with the object to be attached conveyor belt 72, a two-dimensional image can be formed on the object to be attached 30.

[0118] Furthermore, the light-absorbing material 20 that is supported on the surface of the light-absorbing material-carrying roller 41 but not flown away accumulates as the light-absorbing material-carrying roller 41 rotates and comes into contact with the supply roller 52, and eventually falls into the storage tank 51 for collection. In addition, the method of collecting the light-absorbing material 20 is not limited to this, and a scraper or the like may be provided to scrape off the light-absorbing material 20 from the surface of the light-absorbing material-carrying roller 41.

[0119] Figure 6B is an explanatory diagram showing another example of the image forming apparatus shown in Figure 5B, with the addition of a light-absorbing material supply means and a means for transporting the object to be attached. In Figure 6B, the image forming apparatus 303 is a modified version of the image forming apparatus 302 shown in Figure 6A, in which the cylindrical light-absorbing material carrying roller 41 in the image forming apparatus 302 is divided into two parts along the axial direction to form a light-absorbing material carrying section 42, and the arrangement of the image forming apparatus 302 is changed.

[0120] The light-absorbing material carrying section 42 is a cylindrical part with no surface on the side opposite the cylindrical centerline. By using a carrying body without opposing surfaces in this way, the optical path of the optical vortex laser beam 12 can be easily secured without having to install the optical vortex laser beam irradiation unit 100 on the cylindrical light-absorbing material carrying roller 41, thus simplifying the device.

[0121] Figure 7A is an explanatory diagram showing an example of the image forming apparatus shown in Figure 6A with a fixing means added. In Figure 7A, the image forming apparatus 305 has fixing means 80 in addition to the means of the image forming apparatus 302 shown in Figure 6A, to fix the light-absorbing material 20 attached to the object to be attached 30 and make it smooth. Note that the position of the object to be attached transport means 70 was on the side of the light-absorbing material carrying roller 41 in Figure 6A, but in Figure 7A, for the sake of explanation, it is positioned above the light-absorbing material carrying roller 41.

[0122] The fixing means 80 is a pressurized fixing means, positioned downstream of the light-absorbing material carrying roller 41 in the transport direction indicated by arrow C in Figure 7A of the object to be attached 30, and has a pressurized roller 83 and an opposing roller 84. This fixing means 80 pressurizes and fixes the object to be attached 30 to which the light-absorbing material 20 is attached by transporting it while gripping it.

[0123] The pressure roller 83 is biased toward the opposing roller 84, and its surface is in contact with the object to be attached 30, applying pressure while clamping the object to be attached 30 between the two rollers. The opposing roller 84 is positioned to contact the pressure roller 83, and the object to be attached 30 is clamped between the pressure roller 83 and the object to be attached via the object conveying belt 72.

[0124] For example, if the image forming apparatus 305 is used as the image forming apparatus and a very high viscosity light-absorbing material 20 with a viscosity of 1,000 mPa·s or more is used, the penetration or wetting of the light-absorbing material 20 into the object to be attached 30 tends to be slow. If the light-absorbing material 20 dries in that state, the surface roughness of the image may become rough, and the gloss of the image may decrease. In such cases, the fixing means 80 can press the object to which the light-absorbing material 20 is attached 30 with the pressure roller 83, pushing the light-absorbing material 20 into the object to be attached 30 or crushing the light-absorbing material 20, thereby reducing the surface roughness of the object to which the light-absorbing material 20 is attached 30.

[0125] Figure 7B is an explanatory diagram showing another example of the image forming apparatus shown in Figure 6A, with a fixing means added. In Figure 7B, the image forming apparatus 306 is modified in which the pressure-type fixing means 80 in the image forming apparatus 305 shown in Figure 7A is replaced with a heat-pressure-type fixing means 81. The fixing means 81 is positioned downstream of the light-absorbing material carrying roller 41 in the transport direction indicated by arrow C in Figure 7B of the object to be attached 30, and includes a heating and pressing roller 85, a fixing belt 86, a driven roller 87, a halogen lamp 88, and an opposing roller 84. This fixing means 81 is used when a dispersion liquid containing a material that needs to be melted is used as the light-absorbing material 20, and when the desired image cannot be obtained by pressurization alone.

[0126] The heating and pressurizing roller 85 is biased toward the opposing roller 84, and heats and pressurizes the object to be attached 30 while clamping it with the opposing roller 84 via the fixing belt 86. The fixing belt 86 is an endless belt shape, stretched over the heated and pressurized roller 85 and the driven roller 87, and its surface is in contact with the object to be attached 30. The driven roller 87 is positioned below the heating and pressing roller 85 and moves in accordance with the rotation of the heating and pressing roller 85. The halogen lamp 88 is placed inside the heating and pressing roller 85 and generates heat to fix the light-absorbing material 20 to the object to be attached 30. The opposing roller 84 is positioned to contact the fixing belt 86 and grips the object to be attached 30 with the pressure roller 83 via the object conveying belt 72.

[0127] Figure 7C is an explanatory diagram showing another example of the image forming apparatus shown in Figure 6A, with a fixing means added. In Figure 7C, the image forming apparatus 307 is modified in which the pressure-type fixing means 80 in the image forming apparatus 305 shown in Figure 7A is replaced with a UV irradiation-type fixing means 82. The fixing means 82 is positioned downstream of the light-absorbing material carrying roller 41 in the transport direction indicated by arrow C in Figure 7C of the object to be attached 30, and has a UV lamp 89. This fixing means 81 is used when an ultraviolet-curable material is used as the light-absorbing material 20, and fixes it to the object to be attached 30 by irradiating it with UV light from the UV lamp 89.

[0128] Figure 8A is an explanatory diagram showing an example of the image forming apparatus of the present invention. In Figure 8A, the image forming apparatus 200 has three light-absorbing flight units 120 in addition to the means of the image forming apparatus 306 shown in Figure 7B, and the light-absorbing material 20 is replaced with a coloring agent 21. Furthermore, the light absorber flight unit 120 is composed of a light absorber supply means 50, a light absorber flight means 1, a beam scanning means 60, a light absorber carrying roller 41, and a light absorber 20.

[0129] The light-absorbing flight units 120Y, M, C, and K each store four toners as colorants 21, which are process colors: yellow (Y), magenta (M), cyan (C), and black (K). This allows for the sequential formation of images of each color on the recording medium 31 and can be applied to a color process to obtain a color image.

[0130] Figure 8B is an explanatory diagram showing another example of the image forming apparatus of the present invention. In Figure 8B, the image forming apparatus 201 has an intermediate transfer means 90 as a transfer means, in addition to the means of the image forming apparatus 200 shown in Figure 8A.

[0131] The intermediate transfer means 90 includes an intermediate transfer body 91, an intermediate transfer body driving roller 92, and an intermediate transfer body driven roller 93. The intermediate transfer body 91 is, for example, an endless belt, positioned above the four light-absorbing flight units 120, and stretched by an intermediate transfer body drive roller 92 and an intermediate transfer body driven roller 93. The intermediate transfer body drive roller 92 rotates in the direction indicated by arrow R2 in Figure 8B by the rotational drive means, causing the intermediate transfer body 91 to rotate. The intermediate transfer body driven roller 93 moves in accordance with the rotation of the intermediate transfer body driven roller 92. Thus, an image may first be formed on the intermediate transfer body 91 and then transferred to the desired recording medium 31. In this image forming apparatus 201 as well, high-quality color images can be obtained, similar to the image forming apparatus 200. Furthermore, since the image formed on the intermediate transfer body 91 is pressed by the intermediate transfer body drive roller 92 when transferring it to the recording medium 31, the surface roughness of the recording medium 31 to which the coloring agent 21 is attached can be reduced, similar to the image forming apparatus 200.

[0132] Furthermore, while Figure 5B shows the direction of irradiation of the optical vortex laser beam as being in the direction of gravity, Figures 5A and 6A to 8B show the direction of irradiation being in the opposite direction to gravity or in the horizontal direction. Thus, in the image forming method of the present invention, the direction of irradiation of the optical vortex laser beam onto the surface of the substrate 40 may be in a non-gravity direction, and liquid columns or droplets may be formed in a non-gravity direction. This increases the degree of freedom in the design of the apparatus.

[0133] Figure 9 is an explanatory diagram showing an example of a manufacturing apparatus for three-dimensional objects according to the present invention. In Figure 9, the three-dimensional object manufacturing apparatus 500 includes a molded object support substrate 122, a stage 123, and a three-dimensional object manufacturing head unit 130. This three-dimensional object manufacturing apparatus 500 manufactures a three-dimensional object 124 by layering and curing the attached three-dimensional object manufacturing agent 22. The 3D modeling head unit 130 is positioned on top of the manufacturing apparatus 500 for 3D models and can be scanned in the direction indicated by arrow L in the figure by a driving means. This 3D modeling head unit 130 includes a light absorber flight unit 120 and an ultraviolet irradiator 121.

[0134] The light absorber flight unit 120 is positioned in the center of the 3D modeling head unit 130 and launches the light absorber 20 downwards, causing it to adhere to the modeling support substrate 122 or the already cured light absorber 20. The ultraviolet irradiators 121 are positioned on both sides of the light absorber flight unit 120, and the ultraviolet light is irradiated onto the light absorber 20 that has been launched by the light absorber flight unit 120 to cure it. The molded object support substrate 122 is located at the bottom of the three-dimensional object manufacturing apparatus 500 and serves as the substrate when the three-dimensional molding head unit 130 forms layers of the molding agent 22. The stage 123 is positioned below the object support substrate 122, and the object support substrate 122 can be moved vertically in the figure by a driving mechanism. Furthermore, the stage 123 can be moved in the direction indicated by arrow H in the figure, allowing adjustment of the gap between the 3D printing head unit 130 and the 3D printed object 124.

[0135] In the image forming apparatus and the manufacturing apparatus for three-dimensional objects, examples were shown in which the object to be attached, the recording medium to be attached, and the substrate supporting the object to be attached are transported or moved. However, the apparatus is not limited to these examples, and the object to be attached may be kept stationary while the light absorber flight unit is moved. Alternatively, both the object to be attached and the light absorber flight unit may be moved. Furthermore, in cases where an image of the entire surface of the recording medium is to be formed simultaneously, both devices may remain stationary at least during recording, with only the laser operating. [Examples]

[0136] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments. In the following, we will describe examples and comparative examples in which a pulsed optical vortex laser beam, generated by the light-absorbing material flight mechanism shown in Figure 5B, is irradiated onto UV ink, which acts as a light-absorbing material, to form dots on the object to be coated.

[0137] (Example 1) <Substrate, light-absorbing material, and attached material> A UV ink with the following formulation was applied to the surface of a microscope slide (Matsunami Glass Industry Co., Ltd., Micro Slide Glass S7213; transmittance of 532nm wavelength light is 99%) as a light-absorbing material, forming a film with an average thickness of 20 μm. At this time, the transmittance of 532nm wavelength light in the film-like light-absorbing material was 0.01% or less (absorbance of 4 or more). The viscosity of the UV ink was measured at 25°C using a rotational viscometer (VISCOMATE VM-150III, Toki Sangyo Co., Ltd.) and was found to be 4 Pa·s. ·UV Core TYPE-A Red (manufactured by T&K TOKA Co., Ltd.) 100 parts by mass ·UV Flexo 500 Beni (manufactured by T&K TOKA Co., Ltd.) 50 parts by mass

[0138] Next, the substrate coated with the light-absorbing material was positioned so that the surface of the substrate faced the object to be attached, and a vortex laser beam was irradiated perpendicularly from the back surface of the light-absorbing material. POD gloss coated paper (manufactured by Mitsubishi Paper Mills Ltd.) was used as the substrate, and the gap between the substrate and the light-absorbing material was set to 1.5 mm.

[0139] <Means of launching light-absorbing materials> The light-absorbing material flight mechanism comprises a laser light source, a beam diameter changing member, a beam wavelength changing element, a spatial light modulator (LCOS-SLM X13267 manufactured by Hamamatsu Photonics) as an optical vortex conversion unit, and a quarter-wave plate as a polarization conversion unit.

[0140] As the laser light source, a laser light source (YAG) fabricated in-house at the Omatsu Laboratory, Graduate School of Integrated Science and Technology, Chiba University was used. Using this laser light source, a single-pulse laser beam was generated with a wavelength of 532 nm, a beam diameter of 1.25 mm × 1.23 mm, a pulse width of 2 nanoseconds, and a pulse frequency of 50 Hz. The generated single-pulse laser beam was converted into an optical vortex laser beam using a spatial light modulator (LCOS-SLM X13267, Hamamatsu Photonics). Next, the optical vortex laser beam converted by the spatial light modulator was passed through a quarter-wave plate (QWP; manufactured by Optical Technology Co., Ltd.) located downstream of the spatial light modulator. At this time, the optical axes of the helical phase plate and the quarter-wave plate were set to +45° so that the total rotational moment J, expressed by equation (1) above, was 2. The converted optical vortex laser beam was passed through an energy adjustment filter (ND filter, manufactured by Sigma Koki Co., Ltd.) to adjust the laser output when irradiating the light-absorbing material to 50 μJ / dot. The optical vortex laser beam was then irradiated through a focusing lens (YAG laser focusing lens, manufactured by Thorlabs) to adjust the beam diameter to Φ80 μm when irradiating the light-absorbing material. In Example 1, the orbital angular momentum quantum number was varied to 1, 2, and 3 to form the flying object. The flight states of the flying object when the orbital angular momentum quantum number was varied to 1, 2, and 3 are shown in Figures 10A to 10C.

[0141] (Example 2) In Example 1, the film was formed in the same manner as in Example 1, except that the optical vortex conversion unit was changed from a spatial light modulator to a helical phase plate.

[0142] (Comparative Example 1) In Example 1, a film was formed in the same manner as in Example 1, except that an energy adjustment filter was set to change the diameter of the liquid column or droplet.

[0143] In Examples 1 and 2 and Comparative Example 1, the "flight state," "adhesion state," and "controllability of adhesion amount" were evaluated. The results are shown in Tables 1 and 2.

[0144] <Evaluation of flight status> In Examples 1 and 2 and Comparative Example 1, the flight state of a UV ink used as a light-absorbing material when an optical vortex laser beam was irradiated onto it was captured using a high-speed video camera (HyperVision HPV-X, manufactured by Shimadzu Corporation) from a direction perpendicular to the flight direction of the light-absorbing material, with each frame lasting 100 ns, and evaluated according to the following criteria. [Evaluation Criteria] ○: The laser beam converges along the optical path axis and travels in a straight line. △: The laser beam converges along its optical path axis, but its directivity is slightly disrupted. ×: The laser beam spreads out beyond its diameter and flies.

[0145] <Evaluation of adhesion status> In Examples 1 and 2 and Comparative Example 1, the adhesion state of the light-absorbing material to the object to which it was deposited was evaluated according to the following criteria. The results of the adhesion state are shown in Table 1. If the evaluation is ○ or △, it is at a level that does not pose a problem in practical use. [Evaluation Criteria] ○: No scattering △: Slight scattering present ×: Spray present

[0146] <Evaluation of the controllability of adhesion amount> The laser profiles and dot diameters (μm) of the dots transferred to paper in Examples 1 and 2 and Comparative Example 1 were measured using a digital microscope (VHX-5000, manufactured by Keyence Corporation), and the average dot diameter D (μm) of the three dots was calculated. Furthermore, the roundness of the dots transferred to paper was calculated using a self-developed analysis program. The roundness of the dots is given by the following formula. Roundness = 4π × (dot area) / (dot perimeter) 2 Furthermore, when the starting angular motion quantum number L is changed in the spatial light modulator, the beam spot diameter of the optical vortex is proportional to √(L+1). Figures 12A to 12C show photographs of the dots when the starting angular motion quantum number L is changed to 1, 2, and 3. [Evaluation Criteria] ○: The dot changes according to the diameter of the optical vortex laser, and the roundness of the dot diameter is 0.7 or higher. △: The dot changes according to the diameter of the optical vortex laser, but the roundness of the dot diameter is less than 0.7. ×: The dots scatter, making it impossible to measure the dot diameter and roundness.

[0147] [Table 1]

[0148] [Table 2]

[0149] (Example 3) <Substrate, light-absorbing material, and attached material> A film with an average thickness of 10 μm was formed on a microscope slide (manufactured by Matsunami Glass Industry Co., Ltd., Micro Slide Glass S7213; transmittance of 532 nm wavelength light is 99%) as a substrate, by coating the surface with silver nano-ink (manufactured by Daicel Corporation, Picosil® DNS351S) as a light-absorbing material. At this time, the transmittance of 532 nm wavelength light in the film-like light-absorbing material was 0.01% or less (absorbance of 4 or more). The viscosity of the silver nano-ink was 12 Pa·s according to the spec sheet. The silver nano-ink becomes conductive when heated to approximately 200°C.

[0150] Next, similarly, the substrate coated with the light-absorbing material was positioned so that the surface of the substrate faced the object to be attached, and a vortex laser beam was irradiated perpendicularly from the back surface of the light-absorbing material. As the material to be attached, the same type of microscope slide (Matsunami Glass Industry Co., Ltd., Micro Slide Glass S7213) was used, and the gap between the material to be attached and the light-absorbing material was set to 1.0 mm.

[0151] <Means of launching light-absorbing materials> The configuration of the light-absorbing material flight means is the same as in Example 1. The converted optical vortex laser beam is passed through an energy adjustment filter (ND filter, manufactured by Sigma Koki Co., Ltd.) to adjust the laser output when irradiating the light-absorbing material. The optical vortex laser beam is then irradiated through a focusing lens (YAG laser focusing lens, manufactured by Thorlabs) to adjust the beam diameter to Φ40 μm when irradiating the light-absorbing material. Figure 13 shows a photograph of the silver nanoink dot array when the orbital angular momentum quantum number is set to 1. The dot array was obtained after heating the dot array at 200°C for about 10 minutes using a hot plate.

[0152] In Example 3, the silver nanoink wires necessary for the circuit were formed by creating a denser dot row, as shown in Figure 13. Furthermore, silver nanoink wires formed by changing the orbital angular momentum quantum number to 1 or 2 are shown in Figures 14A to 14B. The wires, like the dot row, were heated on a hot plate at 200°C for about 10 minutes. The volume resistivity of these wires was measured using the four-terminal method and was 5 to 10 μΩcm, indicating that they are sufficiently usable as wiring.

[0153] (Comparative Example 2) In Example 2, the formation of silver nano-ink wires was carried out in the same manner as in Example 2, except that the laser light source was not converted to an optical vortex but was instead a Gaussian beam. The results are shown in Figure 15.

[0154] In Example 3 and Comparative Example 2, the "adhesion state" was evaluated. The results are shown in Table 3.

[0155] <Evaluation of adhesion status> In Example 3 and Comparative Example 2, the condition of the silver nano-ink wire (conductivity or breakage) was visually observed, and the surface roughness Ra was measured five times at different locations within a 750 μm field of view using a laser microscope (VK-X1000, manufactured by Keyence Corporation). The adhesion state was then evaluated based on the following evaluation criteria. The measurement direction was the longitudinal direction through which the current flows. Silver nano-ink wires were fabricated to a length of 5 mm or more, and conductivity was measured at a length of 5 mm. The reference value for the surface roughness Ra was determined by the skin thickness. Skin thickness is the phenomenon that occurs when alternating current flows through wiring; at high frequencies, the current flows only on the surface of the conductor, increasing electrical resistance and making it difficult for current to flow. It is known that when the surface roughness Ra is smaller than the skin thickness δ, the current loss (conductor loss) is reduced. The formula for calculating the skin thickness δ is shown in equation (3) below. [ka] In equation (3) above, ω represents the angular frequency of the current, μ represents the permeability, and σ represents the electrical conductivity. Using the physical properties of silver at 25°C and 28GHz assumed for 5G communication, δ = 0.39 μm, and this value was used as the reference for surface roughness Ra. [Evaluation Criteria] ○: Surface roughness Ra is 0.39 μm or less, and it is electrically conductive. △: Surface roughness Ra greater than 0.39 μm and electrically conductive. ×: Broken wire

[0156] [Table 3]

[0157] Examples of the present invention are as follows: <1> By irradiating the surface of a substrate on which a light-absorbing material is disposed with an optical vortex laser beam on the side of the substrate opposite to the side on which the light-absorbing material is disposed, a liquid column or droplet having a diameter smaller than the irradiation diameter of the optical vortex laser beam is generated from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam. This is a method for generating a flying object using an optical vortex laser, characterized by adjusting the amount of liquid column or droplet by changing the orbital angular momentum quantum number of the optical vortex laser beam. <2> The orbital angular momentum quantum number of the optical vortex laser beam is changed by a spatial light modulator and a helical phase plate. <1> This is the method for generating flying objects as described in [the document]. <3> The orbital angular momentum quantum number of the optical vortex laser beam is changed by a spatial light modulator. <2> This is the method for generating flying objects as described in [the document]. <4> By irradiating the surface of a substrate on which a light-absorbing material is disposed with an optical vortex laser beam onto the surface of the substrate opposite to the side on which the light-absorbing material is disposed, a liquid column or droplet with a diameter smaller than the irradiation diameter of the optical vortex laser beam is generated from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam, and the amount of the liquid column or droplet is adjusted by changing the orbital angular momentum quantum number of the optical vortex laser beam. This is a method for transferring a flying object using an optical vortex laser, characterized by bringing the aforementioned liquid column or droplet into contact with a transfer medium and transferring the object. <5> By changing the energy of the optical vortex, the transfer speed of a liquid column or droplet with a diameter smaller than the irradiation diameter of the optical vortex laser beam is changed, and the liquid column or droplet is transferred to a receiver substrate. <4> This is the method for transferring projectiles as described in [reference]. <6> A light-absorbing material flight means for a substrate on which a light-absorbing material is disposed, wherein an optical vortex laser beam is irradiated onto the surface of the substrate opposite to the side on which the light-absorbing material is disposed, thereby generating liquid columns or droplets from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam and with a diameter smaller than the irradiation diameter of the optical vortex laser beam, and adjusting the amount of liquid columns or droplets by changing the orbital angular momentum quantum number of the optical vortex laser beam, A transfer means for bringing the liquid column or droplet into contact with the transfer medium and transferring it, This is an image forming apparatus characterized by having [a certain feature].

[0158] The aforementioned <1> from <3> A method for generating a flying object as described in any of the above, <4> from <5> A method for transferring a flying object as described in any of the above, and the <6> The image forming apparatus described above can solve the aforementioned problems of the conventional method and achieve the objectives of the present invention. [Explanation of Symbols]

[0159] 1. Light-absorbing material flight means 2. Laser light source 3.7 Beam diameter changing member 4. Beam wavelength changing member 5. Helical phase plate (optical vortex conversion section) 6 1 / 4 wave plate (polarization conversion section) 11 Laser beam 12. Optical vortex laser beam 20 Light-absorbing material 21 Colorants 22. 3D modeling agent 30 Adhering object 31 Recording medium 40 Base material 100 Light-absorbing flight units 110 Colorant Flight Unit 120 Three-dimensional modeling material flying unit 124 Three-dimensional sculpture 130 3D Modeling Head Unit 300-307 Image forming apparatus 400, 401 Image forming apparatus 500 Manufacturing equipment for three-dimensional objects [Prior art documents] [Patent Documents]

[0160] [Patent Document 1] WO2016 / 136722 publication

Claims

1. By irradiating the surface of a substrate on which a light-absorbing material is disposed with an optical vortex laser beam on the side of the substrate opposite to the side on which the light-absorbing material is disposed, a liquid column or droplet having a diameter smaller than the irradiation diameter of the optical vortex laser beam is generated from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam. A method for generating a flying object using an optical vortex laser, characterized by adjusting the amount of liquid column or droplet by changing the orbital angular momentum quantum number of the optical vortex laser beam.

2. The method for generating a flying object according to claim 1, wherein the orbital angular momentum quantum number of the optical vortex laser beam is changed by either a spatial light modulator or a helical phase plate.

3. The method for generating a flying object according to claim 2, wherein the orbital angular momentum quantum number of the optical vortex laser beam is changed by a spatial light modulator.

4. By irradiating the surface of a substrate on which a light-absorbing material is disposed with an optical vortex laser beam onto the surface of the substrate opposite to the side on which the light-absorbing material is disposed, a liquid column or droplet with a diameter smaller than the irradiation diameter of the optical vortex laser beam is generated from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam, and the amount of the liquid column or droplet is adjusted by changing the orbital angular momentum quantum number of the optical vortex laser beam. A method for transferring a flying object using an optical vortex laser, characterized by bringing the aforementioned liquid column or droplet into contact with a transfer medium and transferring the object.

5. The method for transferring a flying object according to claim 4, wherein the transfer speed of a liquid column or droplet with a diameter smaller than the irradiation diameter of the optical vortex laser beam is changed by changing the energy of the optical vortex, and the liquid column or droplet is transferred to a receiver substrate.

6. A light-absorbing material flight means for a substrate on which a light-absorbing material is disposed, wherein an optical vortex laser beam is irradiated onto the surface of the substrate opposite to the side on which the light-absorbing material is disposed, thereby generating liquid columns or droplets from the light-absorbing material in the direction of the irradiation of the optical vortex laser beam and with a diameter smaller than the irradiation diameter of the optical vortex laser beam, and adjusting the amount of liquid columns or droplets by changing the orbital angular momentum quantum number of the optical vortex laser beam, A transfer means for bringing the liquid column or droplet into contact with the transfer medium and transferring the liquid, An image forming apparatus characterized by having

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