Image forming apparatuses may form images on media. The images may be formed on the media by ultraviolet (UV) curable ink applied by an ink applicator unit. A radiation source may emit radiation to the UV curable ink on the media. The UV curable ink may be cured by the radiation applied thereto.
Non-limiting examples of the present disclosure are described in the following description, read with reference to the figures attached hereto and do not limit the scope of the claims. In the figures, identical and similar structures, elements or parts thereof that appear in more than one figure are generally labeled with the same or similar references in the figures in which they appear. Dimensions of components, layers, substrates and features illustrated in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. Referring to the attached figures:
Image forming apparatuses may form images on media. The images may be formed on the media with ultraviolet (UV) curable ink applied by an ink applicator unit. A radiation source may emit radiation to the UV curable ink on the media. The UV curable ink may be cured by the radiation applied thereto. However, during the curing process, oxygen from the atmosphere surrounding the ink may penetrate the UV curable ink and may increase a level of radiation to sufficiently cure the UV curable ink. Further, the radiation applied to the UV curable ink on the media may include infrared radiation that may adversely impact the media.
In examples, an image forming apparatus includes, among other things, a UV radiation source module and a dispersion member. The UV radiation source module may emit an electromagnetic spectrum. The dispersion member may separate ultraviolet electromagnetic radiation subtype C (U VC radiation) from at least one of ultraviolet electromagnetic radiation subtype A (UVA radiation) and ultraviolet electromagnetic radiation subtype B (UVB radiation) in the electromagnetic spectrum. The dispersion member may also apply the UVC radiation to the UV curable ink on the media, and subsequently apply the at least one of the UVA radiation and the UVB radiation after the UVC radiation is applied to the UV curable ink on the media. The application of the UVC radiation to the UV curable ink may provide curing to the exposed surface of the UV curable ink. The subsequent application of UVA radiation may provide deep ink curing that cures the UV curable ink beyond its exposed surface while reducing the penetration of oxygen from the surrounding area outside of the UV curable ink into the UV curable ink due to the previously cured expose surface. Consequently, the reduction in the amount of oxygen penetrating into the UV curable ink from the surrounding area outside of the UV curable ink may enable lower levels of radiation to sufficiently cure the UV curable ink.
The dispersion member 15 may separate ultraviolet electromagnetic radiation subtype C (UVC radiation) 21c from at least one of ultraviolet electromagnetic radiation subtype A (UVA radiation) 21a and ultraviolet electromagnetic radiation subtype B (UVB radiation) in the electromagnetic spectrum. The dispersion member 15 may also apply the UVC radiation to the UV curable ink on the media m. The dispersion member 15 may subsequently apply the at least one of the UVA radiation and the UVB radiation after the UVC radiation is applied to the UV curable ink on the media m. In some examples, the UVA radiation may be applied to the UV curable ink on the media after the UVC radiation is applied thereto. Alternatively, the UVB radiation may be applied to the UV curable ink on the media after the UVC radiation is applied thereto. Still yet, both the UVB radiation and the UVA radiation may be applied to the UV curable ink on the media after the UVC radiation is applied thereto such that the UVA radiation is applied to the UV curable ink on the media after the UVB radiation is applied thereto.
The application of the UVC radiation to the UV curable ink may provide curing of the exposed surface of the UV curable ink. Such exposed surface curing may result in as a barrier to prevent oxygen from the atmosphere surrounding the ink surface from penetrating into the ink when the at least one of UVA radiation and UVB radiation is subsequently applied thereto. That is, when the at least one of the UVA radiation and the UVB radiation is applied to the UV curable ink, the exposed surface of the UV curable ink will have already been cured by the UVC radiation. Thus, the subsequent application of UVA radiation may provide deep ink curing that cures the ink beyond its exposed surface while reducing the penetration of oxygen from the surrounding area outside of the UV curable ink into the UV curable ink. Reducing the amount of oxygen penetrating from the atmosphere into the UV curable ink may enable lower levels of radiation to sufficiently cure the UV curable ink. In some examples, the dispersion member 15 may include a prism, a diffraction grating member, and the like.
In some examples, the surface 24a of the shielding member 24 may be configured to at least one of absorb and transmit there through another portion of the electromagnetic spectrum. The shielding member 24, for example, may include a reflector. In some examples, the reflector may be transparent and include a coating to transmit IR radiation and reflect UV radiation. Alternatively, the reflector may be non-transparent such a metal reflector and include a coating to enhance absorption of IR radiation. In some examples, the reflector may be a parabolic reflector to collect the radiation emitted by the source member 23 and form a collimated beam. Alternatively, water can also be used to transmit UV radiation and reflect the IR radiation.
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In some examples, the UVA radiation 21a separated from the UVC radiation 21c by the dispersing member 15 may form a first acute angle θ1 with an optical axis ao of the dispersing member 15. The UVC radiation 21c separated from the UVA radiation 21a by the dispersing member 15 may form a second acute angle θ2 with the optical axis ao of the dispersing member 15 that is greater than the first acute angle θ1. The UVB radiation 21b separated from the UVA radiation 21a and the UVC radiation 21c by the dispersing member 15 may form a third acute angle θ with the optical axis ao of the dispersing member 15 that is less than the second angle θ2 and is greater than the first acute angle θ1. The IR radiation 21i separated from the UVA radiation 21a, UVB radiation 21b, and UVC radiation 21c by the dispersing member 15 may form a fourth acute angle θ4 with an optical axis ao of the dispersing member 15. In some examples, the fourth acute angle θ4 with the optical axis ao of the dispersing member 15 may be less than the first acute angle θ1.
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Alternatively, the diffraction grating member 35 may be a transmission diffraction grating member including a radiation accepting surface. The radiation accepting surface may include a coating to enhance IR reflection. In some examples, a blocking member 14 may block the IR radiation 21i dispersed by the diffraction grating member 35 from reaching the media m. Thus, a media m may move with respect to ink applicator unit 10 and the diffractive grating member 35 in a media advancement direction dm to receive the UVC radiation 21c before the UVA radiation 21a. In some examples, the media may also receive UVB radiation 21b after the UVC radiation 21c and prior to the UVA radiation 21a.
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For example, the dispersing member may form a first acute angle between the UVA radiation and an optical axis of the dispersing member. The dispersing member may also form a second acute angle greater than the first acute angle between the UVC radiation and the optical axis of the dispersing member. In some examples, the electromagnetic spectrum being dispersed into a plurality of spectral components including UVC radiation and at least one of UVA radiation and UVB radiation by a dispersing member may also include forming a fourth acute angle between IR radiation and the optical axis of the dispersing member by the dispersing member and blocking the IR radiation from reaching the media by a blocking member. It may also include forming a third acute angle between the UVB radiation and the optical axis of the dispersing member by the dispersing member that is less than the second acute angle and is greater than the first acute angle. In some examples, the fourth acute angle may be less than the first acute angle.
In block S540, the UVC radiation is applied to the UV curable ink applied on the media. In block S550, at least one of the UVA radiation and the UVB radiation is subsequently applied to the UV curable ink on the media after the UVC radiation. In some examples, the method may also include subsequently applying UVB radiation after the UVC radiation to the UV curable ink applied on the media and prior to the UVA radiation. For example, the method may also include forming a third acute angle between the UVB radiation and the optical axis of the dispersing member by the dispersing member that is less than the second acute angle and is greater than the first acute angle. In some examples, the method may also include at least one of absorbing and transmitting there through by the shielding member an other portion of the electromagnetic spectrum corresponding to IR radiation.
The method may also include selectively moving the media supported by a media support unit and a mounting member having the ink applicator unit, the UV radiation source module, and the dispersing member mounted thereon with respect to each other. In some examples, the selectively applying UV curable ink on the media by the ink applicator unit, the applying the UVC radiation to the UV curable ink applied on the media, and the subsequently applying the UVA radiation after the UVC radiation is applied to the UV curable ink applied on the media are performed in a single pass of curing UV curable ink by the UV radiation source module.
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The present disclosure has been described using non-limiting detailed descriptions of examples thereof and is not intended to limit the scope of the present disclosure. It should be understood that features and/or operations described with respect to one example may be used with other examples and that not all examples of the present disclosure have all of the features and/or operations illustrated in a particular figure or described with respect to one of the examples. Variations of examples described will occur to persons of the art. Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the present disclosure and/or claims, “including but not necessarily limited to.”
It is noted that some of the above described examples may include structure, acts or details of structures and acts that may not be essential to the present disclosure and are intended to be exemplary. Structure and acts described herein are replaceable by equivalents, which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the present disclosure is limited only by the elements and limitations as used in the claims.