JPH065426B2 - Toner image fixing method for sheet for transmission projection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a transmission projection sheet (hereinafter referred to as a toner image before being formed with a toner image, which is used as a projection original of an overhead projector (OHP) by an electrophotographic recording apparatus. OH for obtaining OHP sheets, including sheets)
The present invention relates to a method for fixing a toner image on a P sheet.

[Background of the Invention]

For example, as shown in FIG.
Getting a seat is done.

In the copying machine shown in FIG. 3, a recording sheet P such as a plain paper sheet or an OHP sheet has a toner image transferred from a photosensitive drum 1 rotating in an arrow direction by a transfer device 2 and separated by a separator 3 to convey means. 4, the toner image is transferred to the fixing device 5, and the toner image is fused by passing between the heat roller 6 contacting the toner image forming surface of the fixing device 5 and the pinching roller 7 contacting the opposite surface of the fixing device 5. It is discharged to the outside of the aircraft. When the recording sheet P is thin, for example, 50K paper, the temperature of the heat roller 6 of the fixing device 5 is set to 180 ° C., and when the recording sheet P is thick 110K paper or OHP sheet, it is set to 200 ° C.
The temperature is set to 0 ° C. so that the toner image is completely fixed. However, in the case of an OHP sheet, even if the toner image is completely fixed, if it is used for an OHP projection original, the color of the projected color image such as red becomes blackish. In order to investigate the cause of this, when the fixed OHP sheet was observed with an electron microscope, the toner was fused to the OHP sheet in a state where the toner did not fall off, but there were some toner particles in a shape close to the original shape. It was also confirmed that the peripheral portion of the fixed toner layer was in a state where it was easy to reflect or scatter light. These obstruct the transparency and make the color of the projected image dark. That is, when the transmittance of the OHP sheet where the red toner layer was fixed by the above-mentioned fixing method was measured with light having a wavelength of 700 nm, it was about 40% under the condition that the temperature of the heat roller 6 was set to 200 ° C. Yes, OH
The result projected on P was also blackish red. In this case, the original OHP sheet had a surface made of polyethylene terephthalate (PET) and had a transmittance of 83.
%.

As a method of solving the above-mentioned problem in the OHP sheet, the temperature of the heat roller 6 is further increased, the nip width of both rollers 6, 7 or the contact width to the OHP sheet is widened, or both rollers 6, 7 are used. If the pressure contact force is increased, the toner layer will be fixed to the OHP sheet as a smooth surface layer, the light transmittance will be improved, and the color of the projected image will be clear and the reproducibility will be excellent. It was confirmed. However, since the OHP sheet thus obtained has a heat resistance of about 180 ° C., which does not cause thermal deformation of the ordinary OHP sheet used, it is heat-shrinked and deforms into a wavy shape.

[Object of the Invention]

The present invention has been made to solve the above-mentioned problems in fixing a toner image on an OHP sheet, and even if the toner image is fixed under conditions that do not cause thermal deformation of the OHP sheet, the color of the projected image is clear. It is an object of the present invention to provide a toner image fixing treatment method for an OHP sheet, which provides good reproducibility and reproducibility.

〔The invention's effect〕

According to the present invention, a toner image is fixed on an OHP sheet as described above under conditions that do not cause thermal deformation, and a transparent film is adhered to the toner image fixing surface of an OHP sheet having a transmittance of 40% or less. Furthermore, it was made by finding that the transmittance is improved to 50% or more by sufficiently adhering through a heat roller, and after the toner image is formed on the transmission projection sheet, the sheet is heated and fixed. A toner image fixing treatment method for a transmission projection sheet is characterized in that a toner image is fused to the sheet through a means, and then a transparent film is superposed and adhered on the toner image fusion surface side of the sheet. .

〔Example〕

The present invention will be described below with reference to the embodiments shown in FIGS.

FIG. 1 is a schematic side view showing an example of an apparatus for continuously carrying out the method of the present invention, and FIG. 2 shows that the transmittance is improved by adhering a transparent film to the toner image fixing surface of an OHP sheet. It is a graph.

The apparatus shown in FIG. 1 is used for an electrophotographic recording apparatus as shown in FIG. 3, and includes a heating roller 6 having a built-in heater.
The fixing device 5 provided with the pressure roller 7 having the elastic layer on the surface is the same as that in FIG. That is, the fixing device 5 fixes the toner image on the OHP sheet P ′ having the toner image T formed on the surface. The OHP sheet P ′ having the toner image T fixed thereon advances on the belt conveyor 8 and the transparent film F is superposed on the toner image fixing surface at the position of the transparent film superposing roller 9. When the leading edge of the transparent film F comes into contact with the belt conveyor 8, the transparent film F advances toward the superimposing roller 9, and waits until the OHP sheet P'is sent in that state, and then the leading edge of the OHP sheet P '. When the sheet reaches the vicinity of the superposing roller 9, it is fed onto the belt conveyor 8 at the same speed as the traveling speed of the OHP sheet P ', and superposed on the OHP sheet P'by the superposing roller 9. When the transparent film F is a continuous sheet as in the illustrated example, a cutting means similar to that in a copying machine using roll paper as recording paper is provided in front of the superposing roller 9 although not shown. This cutting means is OHP
Cut according to the length of the sheet P '. At the time of this cutting, the rear end of the OHP sheet P'is disengaged from the rollers 6 and 7 of the fixing device 5, so that the conveyance of the OHP sheet P'and the transparent film F can be temporarily stopped for cutting.

In the illustrated example, a transparent film F having a transparent pressure-sensitive adhesive layer F1 such as a cellophane tape is used, and the release paper F2 attached on the pressure-sensitive adhesive layer F1 is a separating roller 10 (or a bar). It is peeled from the transparent film F at the position of (good). In this case, the cut transparent film F is prevented from being taken in the take-up direction of the release paper F2 by cutting the transparent film F between the superposing roller 9 and the separating roller 10 as much as possible. The release paper F2 is not taken up until the cutting end of the transparent film F comes into contact with the belt conveyor 8 and moves toward the superposition roller 9 or at a position slightly closer to the position. Is carried out, and when the transparent film F is superposed by the superposing roller 9 and sent, the release paper F2 is taken out by a constant tension take-up device or the like.

The OHP sheet P ′ and the transparent film F, which are superposed by the superposing roller 9 and the belt conveyor 8, are sent to the adhering device 11 having the same configuration as the fixing device 5, and the adhering heat roller 12 and the pinching roller 13 are provided. Good adhesion is achieved by passing between them. When cellophane tape is used as the transparent film F, the temperature of the adhesive heat roller 12 may be about 40 to 60 ° C., and the pressure with the pressure roller 13 is also about the pressure of the heat roller 6 and the pressure roller 7 of the fixing device 5. Is enough.

The solid line in Fig. 2 shows a transmittance of 83% when the surface is matt processed.
Fixing device 5 using the OHP sheet P ′ made of PET of
Passing speed 58m / min, and the OHP sheet holding pressure 2 kg / cm ² of the roller 6 to be constant, OHP obtained by fixing the red toner image is changed variously conditions the surface temperature of the heat roller 6
The transmittance of light having a wavelength of 700 nm of the sheet P ′ is shown, and the dotted line indicates that the cellophane tape is laminated on the OHP sheet P ′ as a transparent film F without heating the bonding heat roller 12 (surface temperature 25 ° C.). , Shows the transmittance when passing through the bonding device 11 under the same conditions as the passing speed and the gripping pressure of the fixing device 5, and the alternate long and short dash line shows the transmittance when the bonding heat roller 12 is heated to a surface temperature of 60 ° C. ing. As can be seen from FIG. 2, in the OHP sheet P ′ whose toner has just been fixed by the fixing device 5, the temperature of the fixing heat roller 6 is
Unless the temperature exceeds 220 ° C, the color of the projected image becomes clear. If the transmittance is 55% or more, the transparent film F having the transparent pressure-sensitive adhesive layer F1 adhered only by pressure is When the roller temperature is 190 ° C, the transmittance exceeds 55%, and the temperature of the bonding heat roller 12 is 60 ° C.
When the fixing heat roller temperature is 170 ° C, the transmittance is 55%.
% Will be exceeded.

The present invention is not limited to fixing by heat and pressure using a heat roller, but may be performed only by heating, and the transparent film F is not limited to having a pressure-sensitive adhesive layer, and is not more than the fixing temperature. Alternatively, the transparent film F may be directly heat-bonded or pressure-bonded at that temperature, or the transparent film F may be bonded independently of fixing the toner image. Further, the method of the present invention can be applied to a recording device for recording a single color image and a recording device for recording a multicolor image,
Formation of the toner image on the OHP sheet is not limited to transfer, but may be directly developed.

〔The invention's effect〕

According to the present invention, a toner image can be fixed on an OHP sheet under a fixing condition that does not cause thermal deformation, and a projected image can be made to have excellent color reproducibility.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of an apparatus for continuously carrying out the method of the present invention, and FIG. 2 shows that the transparency is improved by adhering a transparent film to the toner image fixing surface of an OHP sheet. The graph shown in FIG. 3 is a schematic side view of the structure of the electrophotographic copying machine. 5 ... Fixing device, 6 ... Heat roller, 7 ... Nip roller, P '... OHP sheet, T ... Toner image, 8 ... Belt conveyor, 9 ... Laminating roller, F ... Transparent film, F1 ... Pressure sensitive adhesive layer , F2 ... Release paper, 10 ... Separation roller, 11 ... Bonding device, 12 ... Bonding heat roller, 13 ... Bonding pressure roller.

Claims (3)

[Claims] 1. A toner image is formed on a transmission projection sheet, the sheet is passed through a heating and fixing means to fuse the toner image to the sheet, and then a transparent film is formed on the toner image fusion surface side of the sheet. A method for fixing a toner image on a transmission projection sheet, characterized in that: 2. The method of fixing a toner image on a transmission projection sheet according to claim 1, wherein the transparent film is adhered by passing the sheet and the transparent film together through a pair of rollers. 3. The heating and fixing means is a means for nipping and sending the transmission projection sheet by a heat roller and a nipping roller, and the transparent film is also adhered by using the heating and fixing means. 2. A method for fixing a toner image on a transmission projection sheet according to item 1.