JP7275966B2 - Light source for ink drying - Google Patents

Description

The present invention relates to an ink drying light source device that dries water-based ink using an infrared radiation lamp.

Conventionally, heat sources that radiate light from visible light to far infrared rays, such as halogen lamps, carbon heaters, and sheath heaters, have been used as heat sources for drying ink ejected onto media (recording media such as printed matter) from water-based inkjet printers. , a heat source using a semiconductor device that outputs light of a specific wavelength is used.
Halogen lamps, which can achieve high output and high speed rise/fall, are often used as heat sources. Generally, most of the spectral wavelength characteristics of light emitted from a halogen lamp have a peak wavelength at near-infrared wavelengths around 1 μm.

For example, Patent Literature 1 discloses a drying apparatus that dries a transported sheet of paper by radiantly heating it with a plurality of infrared radiation lamps. This technology uses a near-infrared radiation lamp with a wavelength that is easily absorbed by ink and a far-infrared radiation lamp with a wavelength that is easily absorbed by water-based varnish to simultaneously dry sheet paper-like ink and varnish. be.
Thus, light in the near-infrared region (0.7 μm to 2.5 μm) has been regarded as a wavelength region suitable for drying ink.

JP 2017-106843 A

However, depending on the color of ink (yellow, magenta, cyan, black), the absorption wavelength characteristics in the visible to near-infrared region differ. Therefore, when strong light in the visible to near-infrared region is irradiated, there is a noticeable difference in the temperature rise depending on the color of the ink, and some colors are dried and some colors are not dried, resulting in uneven drying. . This drying unevenness leads to deterioration in the quality of printed matter.
Accordingly, an object of the present invention is to provide an ink drying light source device capable of suppressing uneven drying of water-based ink.

In order to solve the above problems, one aspect of the ink drying light source device according to the present invention irradiates a medium conveyed in a predetermined conveying direction with light, and dries water-based ink that has landed on the medium. A light source device for drying ink provided with a halogen lamp, wherein the halogen lamp comprises an arc tube having a filament inside and filled with a halogen gas, and a portion of the outer wall of the arc tube. a coating layer that shifts the peak wavelength range of light emitted from the arc tube to the longer wavelength side with respect to the peak wavelength range of light emitted from the filament; and an opening in which the coating layer is not provided, wherein the opening is formed with an opening angle of 180 degrees or less with respect to the tube axis center of the arc tube, and the medium is conveyed. A first area on the transport path irradiated only with a first ray emitted from the arc tube through the coating layer, and a wavelength shorter than that of the first ray emitted from the opening of the arc tube. a second area irradiated with at least a second ray that is light having a peak on the side, and at least one of the position and size of the second area is set according to the opening angle and formation of the opening It is configurable based on at least one of the locations.

This allows the medium to be irradiated with light emitted from the aperture of a single halogen lamp and light emitted through the coating layer and shifted to the longer wavelength side. In other words, light having a spectral distribution close to the absorption band of the pigment contained in the water-based ink and light having a spectral distribution close to the absorption band of the water (solvent) contained in the water-based ink can be emitted in a balanced manner. . Therefore, it is possible to uniformly dry the ink by acting not only on the ink pigment but also on the ink solvent, thereby suppressing unevenness in drying due to the color of the ink.
Further, it is possible to separately set a first area that acts on the ink solvent to uniformly dry the ink and a second area that acts on the ink pigment to increase the drying speed of the ink. Therefore, it is possible to appropriately balance the amount of irradiation energy of the first light beam and the second light beam.
In addition, since at least one of the position and size of the second area can be set, it is possible to adjust the irradiation timing and irradiation energy amount of the second light beam to the medium. For example, the smaller the opening angle of the aperture, the smaller the amount of irradiation energy of the second light beam (increasing the ratio of the irradiation energy amount of the first light beam), and the longer the peak wavelength of the light irradiated onto the medium. It can be shifted to the wavelength side. That is, it is possible to appropriately adjust the balance between the output in the absorption wavelength band of the ink solvent and the output in the absorption wavelength band of the ink pigment.

In addition, the ink drying light source device may further include a reflecting member arranged to face the opening and reflecting the light emitted from the opening toward the medium.
In this case, the medium can be indirectly irradiated with the light emitted from the opening. In addition, the optical path length from the aperture to the irradiation onto the medium can be lengthened. Therefore, the light that acts on the ink pigment can be reduced for irradiation, and uneven drying can be appropriately suppressed.
Furthermore, in the ink drying light source device described above, the reflecting member may be a condensing reflecting mirror that condenses the light emitted from the opening onto a predetermined area on the medium. In this case, the irradiation area of the light acting on the ink pigment can be appropriately set.

Furthermore, in the ink drying light source device described above, the first area may be set downstream of the second area in the transport direction. In this case, in the first area set on the downstream side, it is possible to appropriately evaporate the water content of the undried ink remaining on the medium.
In the ink drying light source device described above, the first area, the second area, and the first area may be set in order from the upstream side in the transport direction. In this case, the moisture in the ink is first evaporated, then the ink pigment absorbs heat to accelerate the drying of the ink, and finally the remaining moisture can be evaporated. Therefore, unevenness in drying can be suppressed more appropriately.

In the ink drying light source device described above, the first light ray may be mid-infrared to far infrared light, and the second light ray may be visible light and near-infrared light. In this case, since the spectral wavelength distribution from visible light to far infrared rays can be controlled with a single lamp, the ink solvent and the ink pigment can be appropriately acted on to dry the ink.
Furthermore, in the ink drying light source device described above, the second area may be an area irradiated with the first light beam and the second light beam. In this case, the second area can be irradiated with the combined light of the first ray and the second ray, so that both the ink pigment and the ink solvent can be acted upon to promote the drying of the ink.

According to one aspect of the present invention, it is possible to radiate light exhibiting the same light absorption characteristics from a single lamp regardless of the color of the ink, and to suppress uneven drying of the ink.

1 is a schematic configuration diagram of an ink drying light source device according to the present embodiment; FIG. FIG. 4 is a diagram showing spectral distributions of light emitted from a clear tube and light emitted from a black tube; FIG. 4 is a diagram showing absorption wavelength characteristics of ink; It is a figure for demonstrating the absorption wavelength characteristic of water. FIG. 3 is a diagram showing spectral distributions of light emitted from a clear tube and a black tube; FIG. 4 is a diagram showing the spectral distribution of light emitted from the ink drying light source device of the present embodiment; FIG. 5 is a schematic configuration diagram showing another example of the ink drying light source device;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an ink drying light source device 100 according to the present embodiment.
This ink drying light source device 100 is a light source device for drying water-based ink (hereinafter also simply referred to as “ink”) that has landed on a medium (printed matter) 200 by a water-based inkjet printer. The ink drying light source device 100 irradiates light onto the medium 200 on which ink has landed, which is transported in a predetermined transport direction by a transport mechanism including rollers 300 and the like, and dries the ink that has landed on the medium 200 .

As shown in FIG. 1 , the ink drying light source device 100 includes a halogen lamp 10 and a reflector (reflecting member) 20 .
A halogen lamp is a lamp in which a tungsten filament is placed as a light-emitting body in an arc tube made of quartz glass or the like, and the arc tube is filled with an inert gas and a halogen gas containing a trace amount of a halogen element or a halogen compound. be. By applying a voltage to the filament and passing a current through it, heat can be generated and used as a heat source.
Halogen lamps typically emit light in the visible to near-mid-infrared range. The filament of a halogen lamp emits light according to the spectral wavelength characteristics of tungsten, with a near-infrared wavelength around 1 μm as a peak. absorbed and not emitted outside the arc tube. Therefore, the spectral distribution of a normal halogen lamp has a peak wavelength near 1 μm, as indicated by dotted line C in FIG.
Visible light is light of 0.4 μm or more and less than 0.7 μm, near infrared light is light of 0.7 μm or more and less than 2.5 μm, mid-infrared light is light of 2.5 μm or more and less than 4.0 μm, far infrared light is light of 4 μm or more. say light.

Halogen lamps, on the other hand, are also capable of emitting light up to far infrared rays. In that case, a colored heat-resistant coating (especially a black coating) is applied to the outer wall of the arc tube (glass) of the halogen lamp. As a result, the radiant energy emitted from the inside of the arc tube is absorbed by the coating layer formed on the outer wall, and far-infrared light is emitted by re-radiation from the coating layer. As described above, the spectral distribution of the halogen lamp with the coating layer is such that the emission peak wavelength region is shifted to the longer wavelength side than that of the ordinary halogen lamp indicated by the dotted line C, as shown by the solid line B in FIG. Become.
However, the radiant intensity in this case is lower than that of the ordinary halogen lamp indicated by the dotted line C. This is because the light emitted through the coating layer is the radiant energy emitted from inside the arc tube that is absorbed by the coating layer and part of the energy is re-radiated. As shown by the solid line B in FIG. 2, the peak of the radiation intensity is reduced to about 1/10 of the peak of the radiation intensity shown by the dotted line C. FIG.
In the following description, the ordinary halogen lamp is referred to as "clear tube", and the halogen lamp provided with the coating layer is referred to as "black tube".

As shown in FIG. 1, the halogen lamp 10 in this embodiment includes an arc tube 11, a coating layer 12 provided on a portion of the outer wall of the arc tube 11, and a coating layer 12 formed on a portion of the outer wall of the arc tube 11. , and an opening 13 in which the coating layer 12 is not provided. Here, the opening 13 is formed so that the opening angle θ with respect to the center of the tube axis of the arc tube 11 is 180 degrees or less (not including 0 degrees). That is, the halogen lamp 10 has a structure in which the coating layer 12 is applied to part of the outer wall of the arc tube of the clear tube. In other words, the halogen lamp 10 has a structure in which the opening 13 is formed in a part of the outer wall of the arc tube of the black tube.
Here, the coating layer 12 can be, for example, a ceramic coating film containing a black pigment in a ceramic material. Such a black ceramic coating film efficiently absorbs light, rises to a sufficiently high temperature, converts the visible light and near-infrared light emitted from the filament into far-infrared light, and radiates (re-radiates). can do.

The halogen lamp 10 is arranged at a position facing the medium 200 being transported. Specifically, the halogen lamp 10 is arranged so that the surface on which the coating layer 12 is applied faces the medium 200 and the opening 13 is located on the opposite side of the medium 200 .
The reflector 20 is arranged at a position facing the opening 13 of the halogen lamp 10 and reflects the light emitted from the opening 13 toward the media 200 . The reflector 20 is a condensing reflecting mirror that reflects the light emitted from the opening 13 of the halogen lamp 10 and converges the light on a predetermined area on the medium 200 .

In this embodiment, the reflector 20 is designed so that the light emitted from the opening 13 of the halogen lamp 10 is not reflected back into the arc tube 11 of the halogen lamp 10 again. The shape and posture are determined so that the light emitted from the opening 13 of the lamp 10 is reflected by the reflector 20 and guided to the medium 200 . However, the shape and posture of the reflector 20 are not limited to the shape and posture shown in FIG.

In this manner, the ink drying light source device 100 emits the first light beam La through the coating layer 12 of the halogen lamp 10 and the second light beam Lb that passes through the opening 13 of the halogen lamp 10. is irradiated onto the medium 200 . Here, the emission peak wavelength range of the first ray La is in the far-infrared range, and the emission peak wavelength range of the second ray Lb is in the visible to near-infrared range. That is, unlike the emission peak wavelength range of the first ray La and the emission peak wavelength range of the second ray Lb, the emission peak wavelength range of the first ray La is on the longer wavelength side than the emission peak wavelength range of the second ray Lb. is formed in
The first light beam La includes far-infrared light emitted from the halogen lamp 10 directly through the coating layer 12, and light emitted from the opening 13 of the halogen lamp 10 and reflected by the reflector 20. , and light in the far-infrared region emitted through the coating layer 12 may be included.

On the transport path along which the medium 200 is transported, the light irradiation range of the first light beam La is set wider than the light irradiation range of the second light beam Lb. Also, the light irradiation range of the second light beam Lb is set to be part of the light irradiation range of the first light beam La. That is, the shape and posture of the reflector 20 are determined so as to converge the second light beam Lb within the light irradiation range of the first light beam La.
In this way, an area irradiated only with the first light beam La and an area irradiated with the first light beam La and the second light beam Lb are set on the transport path along which the medium 200 is transported. . Specifically, as shown in FIG. 1, the first area A ₁ irradiated with only the first light beam La, the first light beam La and the second light beam Lb are irradiated in order from the upstream side in the transport direction of the medium 200. A second area A ₂ where only the first light beam La is irradiated _is set.

With such a configuration, the ink drying light source device 100 in this embodiment can irradiate the medium 200 on which the ink has landed with light in a wavelength range from visible light to far infrared rays. The ink drying light source device 100 in this embodiment dries a plurality of inks of different colors that have landed on the medium 200 using light in the wavelength range from visible light to far infrared rays.

By the way, the drying state of the ink in the printed matter is determined by the wavelength of the light emitted from the heat source, the amount of irradiation energy of the light, and the amount of energy absorbed by the media, and the quality of the printed matter is determined by the drying state of the ink. .
Traditionally, light in the visible to near-infrared region has been considered suitable for drying ink, and halogen lamps (clear tubes) have been widely used as heat sources because they can achieve high output and fast rise/fall times. . However, in the visible light to near-infrared region, the absorption wavelength characteristics of light differ for each color of ink. The intensity of light in the visible to near-infrared region emitted from a halogen lamp (clear tube) is strong, and when the halogen lamp is used as a light source for drying ink, it is particularly difficult to distinguish between light-colored yellow ink and dark-colored black ink. Due to the difference in absorption wavelength characteristics, a phenomenon occurs in which the black ink is dried but the yellow ink is not dried, leading to uneven drying.

FIG. 3 is a diagram showing absorption wavelength characteristics of ink. In FIG. 3, among cyan (C), magenta (M), yellow (Y), and black (K), which are pigments of water-based ink, yellow (Y) and black (K) are used. It shows the absorption wavelength characteristics of a certain water (W).
As shown by the dashed line Y in FIG. 3, yellow ink absorbs light up to around 550 nm, but easily transmits light up to around 1400 nm, bordering on around 550 nm. On the other hand, as shown by the solid line K in FIG. 3, black ink has a light absorption band up to around 800 nm, and light is transmitted in the near-infrared region. Further, as indicated by the dotted line W in FIG. 3, water transmits light up to around 1400 nm.

As described above, in the visible light to near-infrared region, the degree of light absorption varies greatly depending on the color of the ink. Therefore, when strong light from visible light to near-infrared light is irradiated, there is a noticeable difference in the temperature rise of the pigment contained in the ink due to the difference in the light absorption band depending on the color of the ink, resulting in uneven drying. phenomenon occurs.
Therefore, in this embodiment, when drying the water-based ink, light irradiation in the visible to near-infrared region, which is the absorption wavelength band of the ink pigment, is reduced, and the absorption wavelength band of the ink solvent (water), which accounts for the majority of the components of the water-based ink, is reduced. A region is provided to irradiate only the light of Then, the temperature of the water contained in the ink is raised in a region where only the light in the absorption wavelength band of the ink solvent (water) is irradiated, and the ink is uniformly dried regardless of the color of the ink.

In this way, by placing the target in water, which is a solvent, it is possible to reduce the temperature difference due to the color of the ink. , drying unevenness can be reduced.
FIG. 4 is a graph showing the absorption wavelength characteristics (transmission wavelength characteristics) of water ("Knowledge of electromagnetic waves in the food industry (1)", Kagaku Gijutsu MOL, pp. 120-128, February 1988 ). As shown in FIG. 4, it is known that the absorption wavelength characteristics of water, which is the ink solvent, are broad absorption wavelength characteristics having peaks mainly around 3 μm and around 6 μm. Therefore, in the present embodiment, light in the mid-infrared to far-infrared range is used as the light in the absorption wavelength band of the ink solvent (water).
Note that FIG. 4 shows the absorption wavelength characteristics (transmission wavelength characteristics) when the size of the water serving as the solvent (water layer thickness) varies between 1 μm and 1 mm. When the ink solvent is the target, the graph for the size of water of 5 μm or less is helpful.

In this embodiment, as shown in FIG. 1 described above, the first area A ₁ irradiated with only the first light beam La, the first light beam La and the second light beam Lb are arranged in order from the upstream side in the conveying direction of the medium 200 . A second area A ₂ is irradiated with , and a first area A ₁ is irradiated with only the first ray La.
Therefore, when the medium 200 is conveyed, first, only the first light beam La is irradiated in the first area _A1 . The first light beam La, which is mid-infrared light and far-infrared light, is absorbed by the water contained in the ink and raises the temperature of the water. That is, in the first area _A1 , the heat absorption of the media 200 (mainly paper) and the heat absorption of the water contained in the ink are performed, and the water contained in the ink is dried.

Next, the first light beam La and the second light beam Lb are irradiated in the second area _A2 . The second ray Lb, which is visible light plus near-infrared light, is absorbed by the ink pigment and raises the temperature of the ink pigment. In other words, in the second area _A2 , heat is absorbed not only by the moisture contained in the ink but also by the ink pigment. In this way, the drying of the ink is accelerated by acting on both the ink solvent and the ink pigment.
Finally, only the first ray La is irradiated again in the first area _A1 . In this last first area _A1 , even if there is ink that has not dried up to the second area _A2 , the moisture contained in the ink that has not dried absorbs heat and is dried.
Through the steps described above, it is possible to evenly dry a plurality of inks of different colors that have landed on the medium 200 .

As described above, the ink drying light source device 100 in this embodiment irradiates the medium (medium) 200 conveyed in a predetermined conveying direction with light, and dries the water-based ink that has landed on the medium 200. A halogen lamp 10 is provided. Here, the halogen lamp 10 includes an arc tube 11 , a coating layer 12 provided on a portion of the outer wall of the arc tube 11 , and an opening 13 formed in a portion of the outer wall of the arc tube 11 . Further, the opening 13 is formed so that the opening angle with respect to the center of the tube axis of the arc tube 11 is 180 degrees or less.

With such a configuration, the halogen lamp 10 can emit mid-infrared to far-infrared light through the coating layer 12 , and visible light and near-infrared light from the opening 13 . In this manner, a single halogen lamp 10 can emit light having a spectral distribution close to the absorption band of the ink pigment and light having a spectral distribution close to the absorption band of the ink solvent (water). Therefore, by irradiating the media 200 with light from the halogen lamp 10, both the ink pigment and the ink solvent can be acted upon to promote drying of the ink. As a result, it is possible to suppress drying unevenness due to ink color.
In addition, there is no need to separately prepare a lamp for emitting mid-infrared light and far-infrared light and a lamp for emitting visible light and near-infrared light, so that the size and space of the apparatus can be reduced. , energy saving can be achieved by eliminating the need for a plurality of lamps.

Furthermore, the ink drying light source device 100 can include a reflector (reflecting member) 20 arranged at a position facing the opening 13 of the halogen lamp 10 . The reflector 20 reflects the light emitted from the opening 13 toward the media 200 . In this case, the coating layer 12 is opposed to the medium 200 to directly irradiate the medium 200 with mid-infrared to far-infrared light radiated through the coating layer 12, while visible light radiated from the opening 13 The medium 200 can be indirectly irradiated with near-infrared light through the reflector 20 .
Since the medium 200 is indirectly irradiated with the light emitted from the opening 13 in this way, the optical path length from the opening 13 to the medium 200 can be increased, and the energy of the light acting on the ink pigment can be increased. The medium 200 can be irradiated with a reduced amount. Therefore, it is possible to appropriately suppress drying unevenness due to ink color.

FIG. 5 is a diagram showing the spectral distribution of light irradiated onto the media from the clear tube and the black tube, respectively, and FIG. 6 is a diagram showing the spectral distribution of light irradiated onto the medium from the ink drying light source device 100 of the present embodiment. be. In FIG. 5, the dotted line C is the spectral distribution of the light emitted from the clear tube, the solid line B is the spectral distribution of the light emitted from the black tube, and the broken line X is the total amount of light of the dotted line C and the solid line B. Similarly, in FIG. 6, the dotted line C' is the spectral distribution of the light emitted from the opening 13 (aperture angle of 60 degrees) of the halogen lamp 10 and irradiated through the reflector 20, and the solid line B' is the distribution through the coating layer 12. The spectral distribution of the irradiated light, the broken line X', is the total amount of light of the dotted line C' and the solid line B'.

As in the present embodiment, mid-infrared to far-infrared light (first ray La) emitted through the coating layer 12 and visible to near-infrared light emitted from the opening 13 and reflected by the reflector 20 ( When the medium is irradiated with the combined light with the second light beam Lb), the peak wavelength of the light irradiated onto the medium can be shifted to the long wavelength side compared to the case where a clear tube and a black tube are used respectively. . For example, when the opening angle of the aperture 13 is 60 degrees, the peak wavelength can be shifted from around 1 μm to around 3 μm as indicated by the dashed line X in FIG. 5 and the dashed line X' in FIG.

That is, the amount of irradiation energy of light in the visible to near-infrared region (second ray Lb), which is the absorption wavelength band of the ink pigment, is changed to light in the mid-infrared region to far-infrared region, which is the absorption wavelength band of the ink solvent (water) ( It can be lowered relative to the amount of irradiation energy of the first light beam La). The ratio of the amount of irradiation energy between the first light beam La and the second light beam Lb can be adjusted by the opening angle of the opening 13, the optical path length of the second light beam Lb emitted from the opening 13 to the medium 200, and the like. is. In this way, a single halogen lamp can control the spectral wavelength distribution from visible light to far infrared rays to some extent, and the ink on the medium 200 can be dried in a well-balanced manner.

By the way, far-infrared light can be absorbed by water, which is the solvent of the ink, to promote drying of the ink. expected to be expected. Therefore, if only the elimination of uneven drying is considered, it is conceivable to use only the black tube as a heat source. However, in this case, depending on the type of media, the transport speed of the media, etc., the ink may not be dried sufficiently.
This is because, in the black tube, light is absorbed by the coating material applied to the outer wall of the arc tube, and part of the light energy is re-radiated and emitted as far-infrared light. This is because the light energy of infrared light is relatively small. When only the black tube is used as a heat source, a relatively long drying time is required, and it is difficult to dry within the desired time.

On the other hand, the halogen lamp 10 in the present embodiment has a function of emitting visible to near-infrared light (second ray Lb) as well as mid- to far-infrared light (first ray La). , it is possible to accelerate the drying by acting on the ink pigment while proceeding with uniform drying by acting on the ink solvent. Also, at this time, the ratio of the mid-infrared and far-infrared light and the visible and near-infrared light in the total amount of heat received by the media 200 can be balanced so as to achieve a desired ratio. It is possible to appropriately dry the ink within a desired drying time while suppressing the drying time.
The balance between the spectral distributions of the first light beam La and the second light beam Lb is appropriately set according to the type of ink, the type of medium 200, the transport speed of the medium 200, and the like.

Furthermore, the ink drying light source device 100 according to the present embodiment includes a first area _A1 irradiated with only the first light beam La, a first light beam La and a second light beam Lb on the transport path along which the medium 200 is transported. A second area A ₂ to be irradiated with and can be set. In this way, an area that acts on the ink solvent to uniformly dry the ink and an area that acts on the ink pigment to increase the drying speed of the ink are set separately, and each area has different characteristics. Light can be applied.

For example, when the first area A ₁ , the second area A ₂ , and the first area A ₁ are set in order from the upstream side in the transport direction of the medium 200, the moisture in the ink is first evaporated, and then the ink pigment absorbs heat. Allows the ink to dry faster and completely evaporates any remaining moisture. In this way, if the first area A1 is set downstream of the second area _A2 in the transport direction _of the medium 200, dry residue remaining on the medium ₂₀₀ can be removed in the first area A1 set downstream. It is possible to appropriately evaporate the moisture of the ink that is not present, and to reliably suppress drying unevenness.

In this way, depending on the positional relationship and size of the first area _A1 and the second area _A2 on the transport path of the medium 200, the ink pigment and the ink solvent It is possible to set the order of light absorption and the amount of absorbed energy. Thereby, the medium 200 can be irradiated with the first light beam La and the second light beam Lb in a desired balance. In this embodiment, at least one of the position and size of the second area _A2 is set based on at least one of the opening angle of the opening 13, the formation position of the opening 13, and the shape and orientation of the reflector 20. It is possible.
As described above, the ink drying light source device of the present embodiment controls the heat distribution spectral distribution characteristics emitted from the single halogen lamp 10, thereby appropriately suppressing the drying unevenness for each ink color. In addition, space saving and energy saving can be realized.

(Modification)
In the above embodiment, as shown in FIG. 1, the case where the medium 200 transport path is linear has been described, but the medium 200 transport path is not limited to the above. For example, as shown in FIG. 7, the transportation path of the media 200 may be curved. By conveying the medium 200 along the outer shape of the halogen lamp 10 as shown in FIG. 7, the distance over which the medium 200 passes through the light irradiation range of the halogen lamp 10 can be kept long. In the case of the transport path shown in FIG. 7, it is possible to set a wide first area _A1 irradiated only with light (first ray) La from mid-infrared to far-infrared rays emitted through the coating layer 12, and the media The amount of far-infrared light energy irradiated to 200 can be increased.

Further, as shown in FIG. 7, a second area A ₂ irradiated with the first light beam La and the second light beam Lb and a first area A irradiated with only the first light beam La are arranged in order from the upstream side in the transport direction. ₁ can also be set. That is, the first area _A1 shown in FIG. 1 can be omitted. Also in this case, in the second area _A2 , both the ink solvent and the ink pigment can be acted on to promote the drying of the ink, and then the remaining moisture can be dried in the first area _A1 .
Furthermore, in the above embodiment, as shown in FIG. 1, the case of using a partially V-shaped reflector 20 has been described, but as shown in FIG. good too. However, the reflector 20 shown in FIG. 1 is preferable because it can efficiently guide the light emitted from the opening 13 to the medium 200 .

Further, in the above-described embodiment, the visible to near-infrared light emitted from the opening 13 is reflected by the reflector 20 and condensed within the light irradiation range of the first light ray La, so that the second light in the second area A ₂ The case of irradiating with the combined light of the one ray La and the second ray Lb has been described. However, the second area _A2 may be irradiated only with the second light beam Lb. In other words, at least the second light beam Lb should be applied to the second area _A2 .
In this case, the visible to near-infrared light emitted from the opening 13 may be reflected by the reflector 20 and condensed outside the light irradiation range of the first light beam La. Further, by omitting the reflector 20 and arranging the medium 200 at a position facing the opening 13, the medium 200 may be directly irradiated with visible to near-infrared light emitted from the opening 13. In the latter case, by adjusting the size (aperture angle) of the opening 13 and the distance from the opening 13 to the medium 200, the energy amount of visible to near-infrared light irradiated to the medium 200 is adjusted. It is possible to balance with the amount of irradiation energy of far-infrared light.

DESCRIPTION OF SYMBOLS 100... Light source device for ink drying, 10... Halogen lamp, 11... Luminous tube, 12... Coating layer, 13... Opening, 20... Reflective member (reflector), 200... Media (printed matter), La... First ray, Lb … second ray

Claims (7)

An ink drying light source device comprising a halogen lamp for irradiating a medium conveyed in a predetermined conveying direction with light to dry water-based ink landed on the medium,
The halogen lamp is
An arc tube having a filament inside and filled with a halogen gas; a coating layer that shifts the peak wavelength range of light emitted from the arc tube to the longer wavelength side;
The opening is formed with an opening angle of 180 degrees or less with respect to the tube axis center of the arc tube ,
A first area irradiated with only a first light ray emitted from the arc tube through the coating layer, and the second area emitted from the opening of the arc tube are placed on the conveyance path along which the medium is conveyed. A second area irradiated with at least a second ray that is light having a peak on the shorter wavelength side than the first ray is set, and at least one of the position and size of the second area is set by the opening can be set based on at least one of the aperture angle and formation position of the ink drying light source device. 2. The light source device for drying ink according to claim 1, further comprising a reflecting member arranged to face the opening and reflecting the light emitted from the opening toward the medium. 3. A light source device for drying ink according to claim 2, wherein said reflecting member comprises a condensing reflecting mirror for condensing the light emitted from said opening onto a predetermined area on said medium. 4. The light source device for drying ink according to claim 3 , wherein the first area is set downstream of the second area in the transport direction. 5. The light source device for drying ink according to claim 1 , wherein the first area, the second area, and the first area are set in order from the upstream side in the transport direction. the first ray is light from mid-infrared rays to far-infrared rays,
5. The ink drying light source device according to claim 1 , wherein the second light beam is visible light and near-infrared light. 5. The light source device for drying ink according to claim 1 , wherein the second area is an area irradiated with the first light beam and the second light beam.

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