Incremental printing of symbolic information – Ink jet – Medium and processing means
Reexamination Certificate
2003-02-12
2004-11-30
Shah, Manish (Department: 2853)
Incremental printing of symbolic information
Ink jet
Medium and processing means
C347S101000
Reexamination Certificate
active
06824264
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus for fixing, by heating, an image formed on a sheet-like recording medium thereto with sublimating ink.
2. Description of the Related Art
An exemplary conventional technique relating to the above field of art is disclosed in Japanese patent application “Kokai” No: Hei. 10-297197. According to this, a metal substrate includes a coloring ground layer acting also as a rust-preventive layer, a transparent resin layer as an optical transparent resin layer formed over the coloring ground layer, the resin layer (made of e.g. porous alumina) being made of acrylic resin, polyester resin, urethane resin etc., and an inkjet receiving layer formed over the resin layer and made of e.g. porous alumina. After application of a sublimating ink or pigment on the inkjet receiving layer by an inkjet printing, the sublimating pigment is heated in a heating furnace or by a hot press, whereby the sublimating pigment in the inkjet receiving layer is sublimed into the transparent resin layer. Then, the inkjet receiving layer is removed to obtain an ornamental metal body having a colored pattern fixedly formed within the transparent resin layer (see, for example, paragraphs Nos. 0010-0013 and FIG.
4
). This image forming art can be applied to a recording medium using, as a substrate thereof, metal material which is hardly deformed by heat. However, if this art is applied to a recording medium using, as a substrate thereof, e.g. resin material which is deformed significantly by heat, occurrence of thermal deformation in the substrate during the heating process, especially, “wrinkles” cannot be avoided.
Further, Japanese patent application “Kokai” No: Hei. 10-16188 discloses an image forming apparatus. According to this, first, a primary image is formed on a thermal transfer sheet by e.g. an inkjet printer. Then, this thermal transfer sheet having the image formed thereon is laid over a recording sheet and these sheets are pressed and heated together by means of heat press rollers whose temperature is controlled, whereby the image (ink) formed on the thermal transfer sheet will be sublimed by the heat and transferred onto an ink fixing layer of the recording sheet (see, for example, paragraphs Nos. 0008-0012 and FIG.
1
). In the case of this image forming technique, the surface temperature control of the heat fixing roller is strictly effected. However, since the contact between the heat press rollers and the recording sheet is substantially line contact, the surface of the recording sheet at the normal temperature (room temperature) is heated and pressed momentarily and then left to cool at the normal temperature again. Therefore, if material such as resin sensitive to heat is employed as the substrate of the recording sheet, wrinkles developed during the heating process will remain after the cooling.
According to further art disclosed by Japanese patent application “Kokai” No: 2001-105638, sublimating ink is transferred from an ink ribbon onto a surface of a recording sheet. In order to heat and fix the ink on the sheet, the sheet is charged into a heater box, in which the sheet is advanced and heated between a press roller and a heat roller opposed to each other with a small gap therebetween or between a heat roll and a conveyer belt disposed along a portion of the peripheral face of the heat roll, and then the sheet is discharged by a transport roller from the heater box immediately (see, for example, paragraph Nos. 0039-0058 and FIG.
1
). With this image forming technique, the recording sheet heated by the heating roller is immediately discharged from the heater box into the normal temperature. Therefore, if material such as resin sensitive to heat is employed as the substrate of the recording sheet, wrinkles developed during the heating process will remain after the cooling.
Further, though differing in the properties in the recording medium from the present invention, in the field of textile printing, according to an exemplary technique disclosed by Japanese patent application “Kokai” No: Hei. 08-311782, in order to obtain a print of a graphic image of as clear definition as possible, printing is effected by means of the inkjet printing method on a textile whose wrinkles were smoothed out by smoothing out rolls. After printing, in order to reinforce the fixing of the dye and also to improve its color development, the textile is charged into a heater device to be heated therein. Then, the textile is discharged from the device immediately to be cooled at the normal temperature (see paragraphs Nos. 0041-0043, 0061-0070 and FIG.
2
). This art, however, does not provide any means for removing “wrinkles” after completion of the heating process. Therefore, if this art is employed for a recording material of not textile but some heat-sensitive material such as resin, the wrinkles developed during the heating process will remain.
SUMMARY OF THE INVENTION
In view of the above, a primary object of the present invention is to provide an image forming apparatus usable for a recording material using a heat-sensitive material such as resin as the substrate thereof as the apparatus has a function for eliminating deformation developed in a recording medium during heating thereof by a heating fixing unit before cooling of the medium.
For accomplishing the above-noted object, according to the present invention, an image forming apparatus for fixing, by heating, an image formed on a sheet-like recording medium thereto with sublimating ink, the apparatus comprising:
a heating fixing unit for receiving and heating the recording medium and then discharging the heat-fixed recording medium, the heating fixing unit including a heating space for heating the recording medium and a transporting mechanism for transporting the medium in the heating space; and
a smoothing-out mechanism for discharging the recording medium from the heating space while smoothing out or flattening the recording medium.
With the above construction, according to the image forming apparatus of the invention, the recording medium printed with image with the sublimating ink is introduced into the heating space by the transporting mechanism, where the medium is exposed to a required heating process for stably fixing the image thereon. And, the resultant recording medium is automatically discharged from the heating space. In the course of this, when the recording medium is being discharged from the heating space, this medium retaining the heat received in the heating space, thus having sufficient plasticity is subjected to the function of the smoothing-out mechanism. Therefore, even if deformation has occurred during the heating for ink fixation or due to application of an external force during its transport, this deformed recording medium may be effectively smoothed out into the appropriate flat shape.
Preferably, the smoothing-out mechanism includes a curved transporting section for forcibly bending the recording medium discharged or being discharged from the heating space into a direction for bending the medium as viewed from its lateral side.
Namely, in this type of recording medium, there tend to develop wrinkles in the form of wave-like undulations in the cross section of the medium. Therefore, with the above-proposed construction, the recording medium is forcibly bent in the direction traversing such wave-like undulations, such that such type of wrinkles may be effectively eliminated or occurrence of such type of wrinkles may be avoided in advance.
Preferably, the curved transporting section is arranged in such a manner as to orient the image-formed face of the recording medium to the outer side. With this, when the recording medium is caused to pass the curved transporting section, a tension will occur on the outer face of the recording medium on which the image is formed and this tension serves to smooth out fine wrinkles on the surface of the medium.
Still preferably, the curved transporting section includes an angular member ext
Funase Masasuke
Inoshita Masanori
Ishikawa Masazumi
Nagaosa Kazuo
Nakamoto Masaki
Fulbright & Jaworski L.L.P.
Noritsu Koki Co., Ltd.
Shah Manish
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