JPH06143813A - Ohp sheet and picture image forming apparatus employing the ohp sheet - Google Patents

Abstract

PURPOSE:To form a picture image on an OHP sheet in use of a general copying machine, and provide an OHP sheet simply inexpensively by forming an OHP sheet with a light transmission sheet, a heat sensitive layer capable of being color-changed at a predetermined temperature or higher, and a mold releasable layer. CONSTITUTION:An OHP sheet 1 includes a light transmission sheet, a heat sensitive layer capable of being color-changed at a predetermined temperature or higher, and a mold releasable layer. The picture image forming apparatus utilizing the OHP sheet includes a picture image forming part for forming a toner image 7 on the OHP sheet, and an infrared rays irradiating part 2 for discoloring the heat sensitive layer 5 of the OHP sheet 1 in the toner image 7 formed part by irradiating Infrared rays on the toner image 7 formed OHP sheet 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an OHP sheet used for presentations and the like and an apparatus for forming an image on the OHP sheet.

[0002]

2. Description of the Related Art In the case of forming an image on an OHP sheet for presentation, for example, a method of forming an image using the OHP sheet having the following structure has been proposed.

This OHP sheet causes a chemical reaction when mixed with a first sheet having a reaction layer laminated on the surface of a translucent sheet and the reaction layer of the first sheet, and discolors the reaction layer. And a milky white second sheet to be obtained.

First, a document is superposed on the first sheet via the second sheet, and this stack is put into an image forming machine. Next, by irradiating the laminate with infrared rays, the image portion of the document absorbs the infrared rays and reaches a high temperature, so that the second sheet in contact with this portion melts and chemically reacts with the reaction layer of the first sheet. Cause As a result, the reaction layer of the first sheet is decolored or colored. On the other hand, the second sheet, which is in contact with the original in the portion where the image is not formed, does not melt because the temperature rise is small and does not chemically react with the reaction layer of the first sheet.

After that, by peeling the second sheet and the original from the first sheet of the laminate discharged from the making machine,
The first sheet on which the image corresponding to the original is formed is obtained.

However, such an OHP sheet image forming method has the following problems.

A dedicated machine for forming an image on an OHP sheet is required.

Since the OHP sheet is composed of the first sheet and the second sheet, the cost of the OHP sheet is relatively high.

After passing the OHP sheet through the making machine, the second
It is troublesome because the sheet needs to be peeled from the first sheet.

Since the original is superimposed on the OHP sheet to form the image, only one OHP sheet can form the image from one original at a time, and the original may be damaged.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and its object is to eliminate the need for using a dedicated OHP sheet making machine and to make a general copying machine. An object of the present invention is to provide an OHP sheet capable of forming an image on an OHP sheet by using, and an image forming apparatus using the OHP sheet.

Another object of the present invention is to provide an OHP sheet which eliminates the need for the second sheet in the conventional OHP sheet and therefore eliminates the need for peeling the second sheet from the first sheet and can reduce the cost relatively. Especially.

Still another object of the present invention is to provide an OHP sheet capable of simultaneously copying a large number of sheets from one original and its OH sheet.
An object is to provide an image forming apparatus using a P sheet.

[0014]

The OHP sheet of the present invention is provided with a light-transmissive sheet, a heat-sensitive layer provided on the light-transmissive sheet and capable of discoloring at a predetermined temperature or higher, and provided on the heat-sensitive layer. The release layer is provided, and the above object is achieved thereby.

In the image forming apparatus using the OHP sheet of the present invention, a toner image is formed by irradiating infrared rays on the OHP sheet on which the toner image is formed and the OHP sheet on which the toner image is formed. O of the part
And an infrared ray irradiating part for changing the color of the heat-sensitive layer of the HP sheet, whereby the above object is achieved.

[0016]

When a toner image is formed on an OHP sheet and infrared rays that can be absorbed by the toner image are radiated over the entire surface of the OHP sheet, the portion where the toner image is formed absorbs the infrared rays and heats up. When the heat-sensitive layer reaches a predetermined temperature or higher due to the conduction of heat, the reaction starts and the color changes. The toner image on the OHP sheet is then removed to obtain an OHP sheet having an image formed on the heat sensitive layer. Here, since the uppermost layer of the OHP sheet is a release layer, and the toner image is in a state of being adhered to this release layer, after the image is formed on the heat sensitive layer, the toner image is formed by mechanical means. Can be easily removed.

Therefore, if the OHP sheet of the present invention is set in the paper feeding section of an electrophotographic image forming apparatus such as a copying machine and a toner image is formed on the OHP sheet, as described above, An image can be easily formed on the OHP sheet.

According to the image forming apparatus of the present invention, an image forming apparatus such as a copying machine having a conventional image forming unit can be used as an OHP.
It can be used in an image forming apparatus for a sheet.

For example, an OHP sheet image forming apparatus can be manufactured by replacing the fixing unit provided in the conventional image forming apparatus with an infrared irradiating section or incorporating an infrared irradiating section.

(Preferred Embodiment) As shown in FIG. 1, the translucent sheet 4 used in the OHP sheet 1 of the present invention is formed of a resin sheet or film capable of transmitting infrared rays having a specific wavelength. The translucent sheet 4 may be colorless and transparent or may be colored. Translucent sheet 4
Can be formed of, for example, a polyethylene terephthalate film, and the thickness thereof is preferably 50 to 200 μm, particularly preferably about 100 μm.

Heat-sensitive layer 5 provided on the translucent sheet 4.
Is a color that changes color by causing a chemical reaction at a certain temperature or higher. Here, discoloration includes decoloring and coloring. When the OHP sheet 1 is colorless and transparent, the heat-sensitive layer 5 is colored at a certain temperature or higher, and when the OHP sheet 1 is colored, the heat-sensitive layer 5 is decolored or has a different color at a certain temperature or higher. The color changes to. When the heat-sensitive layer 5 is colored, the transparent sheet 4 is preferably colorless and transparent or has a color different from that of the heat-sensitive layer 5. Usually, the heat-sensitive layer 5 contains two or more kinds of heat-sensitive materials capable of causing a chemical reaction and discoloration only at a predetermined temperature or higher, and a chemical reaction is caused by melting and mixing of these heat-sensitive materials, and when not reacting. Have different colors or disappear.

When the heat-sensitive layer 5 is colored by heating, for example, a heat-sensitive material composed of a waxy metal compound such as iron stearate and silver behenate, and a phenol compound which reacts with the heat-sensitive material to form a coloring substance are used. A heat-sensitive material, for example, a reducing heat-sensitive material such as pyrogallic acid, gallic acid or tannic acid can be used in combination.

When the heat-sensitive layer 5 is to be decolored by heating, for example, a heat-sensitive material such as crystal violet lactone, quinoline blue, or a cyanine dye, and bisphenol capable of decoloring the heat-sensitive material by reaction with the heat-sensitive material. A, a heat-sensitive material such as sodium borate, and an organic ammonium borate can be used in combination.

The heat-sensitive layer 5 is formed by dispersing these heat-sensitive materials in a binder of a synthetic resin such as polyvinyl alcohol, applying the resulting mixed liquid onto the translucent sheet 4 and drying. The thickness of the heat sensitive layer 5 is not particularly limited, but is preferably 5 to 10 μm.

A release layer 6 provided on the heat sensitive layer 5.
May be any as long as it can easily remove the toner image 7 supplied to the upper surface thereof, and can be formed of, for example, a fluorine resin coating or a silicone oil coating. These materials that form the release layer 6 have poor compatibility with the resin (for example, styrene-acrylic resin) that forms the toner.

When the release layer 6 is formed of a fluorine resin coating, a fluorine resin (for example, tetrafluoroethylene resin) is uniformly applied on the heat-sensitive layer 5 in a thickness of 0.5 to 5 μm. Can be formed. When the release layer 6 is formed of a silicone oil film, the heat-sensitive layer 5 has 3,000 to 30,000 cps.
Silicone oil (for example, KF manufactured by Shin-Etsu Chemical Co., Ltd.)
96 type release agent or SH20 manufactured by Toray Silicone Co., Ltd.
It can be formed by uniformly applying a 0-type release agent or the like) to a thickness of 0.5 to 5 μm. The silicone oil coating can also be formed using a silicone-based hard coating agent (alkoxysilane hydrolyzate).

Further, the release layer 6 can also be formed by using melamine resin, polyurethane resin or the like.
The thickness of the release layer 6 is usually 0.5 to 5 μm, preferably 2 to 3 μm. When the thickness of the release layer 6 is less than 0.5 μm, the releasability of the toner tends to deteriorate, and the toner image is difficult to remove from the OHP sheet. Even if the thickness of the release layer 6 exceeds 5 μm, the effect of enhancing the releasability of the toner is not particularly improved.

The image forming apparatus for the OHP sheet of the present invention is
Photoconductor drum, charging unit, developing unit, transfer unit and separating unit,
An image forming unit including a cleaning unit is provided.
An electrophotographic image forming apparatus such as a conventional copying machine or printer can be used. For example, the fixing unit incorporated in the image forming apparatus may be an infrared irradiation unit,
Alternatively, an infrared irradiation unit may be provided between the fixing unit and the image forming unit. When using the fixing unit as an infrared irradiation unit, replace the conventional heat roller with a lamp that irradiates infrared rays of a specific wavelength and an infrared transparent roller arranged around this lamp. You can In this case, it is preferable that the pressure acting between the rollers is reduced or released. When the fixing unit is used as an infrared irradiation unit, it does not require a space and is suitable for a small apparatus.

When the infrared irradiation section is arranged between the developing section and the fixing section of the copying machine, the mode for forming the toner image on the recording paper and the mode for forming the image on the OHP sheet are switched. In the mode in which the toner image is formed on the recording paper, the infrared irradiation unit is released and the fixing unit functions, and in the mode in which the image is formed on the OHP sheet, the reverse operation is performed. Good.

FIG. 2 shows an example of an image forming apparatus using an OHP sheet in which an infrared irradiation unit is incorporated in a conventional electrophotographic copying machine.

In this image forming apparatus, the photosensitive drum 10 is used.
And a charging unit 11 disposed around the photoconductor drum 10 for uniformly charging the periphery of the photoconductor drum 10.
By exposing the image on the document to the surface of the photoconductor drum 10, the image becomes an electrostatic latent image on the photoconductor drum 10.
An optical system 12 for forming the above, and the photoconductor drum 10
A developing unit 13 for developing the toner image 7 by depositing toner on it, a transfer unit 14 and a separating unit 15 for transferring the toner image 7 on the photosensitive drum 10 onto the OHP sheet 1, A cleaning unit 16 arranged around the photoconductor drum 10 for removing the residual toner on the photoconductor drum 10 and infrared irradiation for irradiating the OHP sheet 1 on which the toner image 7 is formed with infrared rays. A section 2 and a toner removing section 3 for removing the toner image 7 on the OHP sheet 1 are provided.

The infrared irradiating section 2 uses a fixing section for fixing the toner image 7 on the recording paper in a conventional copying machine. For example, a fluorine resin coating film is provided in the conventional fixing section. The heat roller described later is used instead of the aluminum tube whose surface is coated with. The pressure between the rollers in the infrared irradiation unit 2 is
The fixing rate of the toner image 7 formed on the OHP sheet 1 is lowered to about 20 to 60% at the time of normal copying to facilitate the toner removal from the OHP sheet 1 after coloring and erasing.

Next, the infrared irradiation unit 2 will be described in detail.

The infrared irradiating section 2 is a halogen lamp 21 which emits infrared rays of a specific wavelength which can be absorbed by the toner and generate heat.
A transparent heat roller 22 arranged around the halogen lamp 21, a reflecting mirror 23 arranged around the heat roller 22, and a rubber roller arranged so as to face the heat roller 22. 24 and.

The halogen lamp 21 is arranged along the center of the rotation axis of the heat roller 22, and the halogen lamp 2
The preferred wavelength of infrared rays emitted from 1 is 3 to 20 μm
Is. The heat roller 22 is formed of a transparent glass cylinder that can transmit infrared rays having such a specific wavelength, and can be formed of, for example, fused quartz or Pyrex. Further, the reflecting mirror 23 is formed so as to be curved so as to focus the infrared rays emitted from the halogen lamp 21 on the contact portion between the heat roller 22 and the rubber roller 24. The toner removing section 3 can be arbitrarily incorporated in the apparatus, and can be formed by, for example, a cleaning roller or a rubber blade. When performing normal copying, the toner removing unit 3 is released from the paper transport path.

When the toner removing section 3 is composed of a cleaning roller, as shown in FIG.
And a rubber roller 32 that rotates faster than the heating roller 31, and a cleaning blade 33 that comes into sliding contact with the rubber roller 31 is provided so that the toner scraped by the cleaning blade 33 is accommodated. Good.

Further, the toner may be attached to the rubber roller 24 of the infrared irradiating section 2 and scraped off.

Next, using the image forming apparatus having the above structure,
A method of forming an image on the OHP sheet 1 will be described.

As shown in FIG. 2, OHP is used instead of recording paper.
When the sheet 1 is set in the paper feeding section (not shown) of the apparatus and the apparatus is driven while the original is placed on the original supporting glass, the image on the original is transferred to the photosensitive drum 10 by the optical system 12.
An electrostatic latent image is formed on the upper surface, and the latent image is developed by the developing unit 13 to form a toner image on the photosensitive drum 10. Then, the toner image 7 is transferred onto the OHP sheet 1 sent from the paper feeding section.

Then, when the OHP sheet 1 on which the toner image 7 is formed passes through the infrared irradiating section 2, infrared rays are irradiated over the entire surface from the upper surface thereof. Here, the toner image 7 on the OHP sheet 1 is heated by the heat transfer from the toner image 7 that has become high temperature by absorbing infrared rays, and the portion of the OHP sheet 1 where the toner image 7 is formed is heated, so that the toner image 7 is formed. Since the infrared rays are transmitted through the OHP sheet 1 which is not formed, it is not heated. Therefore, as shown in FIG. 1B, the heat-sensitive layer 5 in the portion where the toner image 7 is formed.
The heat of a causes the reaction to start and the color changes. The amount of infrared radiation from the infrared radiation unit 2 is set to such an extent that the heat-sensitive material contained in the heat-sensitive layer 5 melts and reacts, and the high-temperature toner is not fused on the OHP sheet 1. . For example, when the heat-sensitive material starts the reaction at 120 ° C., the glass transition point of a commercially available toner is about 150 ° C., so the heat-sensitive layer 5 may be heated to 120 to 150 ° C.

After that, as shown in FIG.
The toner on the sheet 1 is removed by the toner removing section 3 to obtain the OHP sheet 1 on which an image is formed. Here, since the release layer 6 is formed on the surface of the OHP sheet 1, the toner on the OHP sheet 1 is easily removed.

According to the above method, when the OHP sheet 1 having the heat sensitive layer 5 which becomes colored by heating is used,
An OHP sheet on which a colored image is formed is obtained, and in the case of the OHP sheet 1 having the heat-sensitive layer 5 that is decolored by heating, the OHP sheet 1 with a blank image is obtained.

To remove the toner on the release layer,
It may be performed manually after the OHP sheet is discharged from the copying machine. When the release layer is formed of a silicone oil film, a coating means such as a roll for coating silicone oil may be provided in the apparatus upstream of the image forming unit in the transport direction.

[0044]

EXAMPLES The present invention will be specifically described below based on examples.

(Preparation of OHP Sheet) Liquid A: Crystal Violet Lactone 5 parts by weight 5% Polyvinyl alcohol 30 parts by weight Water 5 parts by weight Liquid B: Bisphenol A 5 parts by weight 5% Polyvinyl alcohol 25 parts by weight Water 10 parts by weight Above A Liquid 2 and Liquid B separately by ball mill 2
After pulverized and dispersed for 4 hours, the liquid A and the liquid B were mixed at a weight ratio of 1: 5 to prepare a coating liquid.

This coating solution was applied onto a polyethylene terephthalate film having a thickness of 100 μm using a wire bar so that the film thickness after drying would be 5 μm, and the temperature was 50 to 60 ° C.
And dried with warm air to form a blue thermosensitive layer. Silicon oil (KF9, manufactured by Shin-Etsu Chemical Co., Ltd.) is formed on the heat-sensitive layer.
6 type release agent) was evenly applied to a thickness of about 2 μm to form a release layer.

(Image Forming Method of OHP Sheet) Using the electrophotographic copying machine shown in FIG. 2, the OHP sheet obtained above is set in the paper feeding section of the copying machine in place of the recording paper, and the original is set. When the copying machine is driven while it is placed on the original supporting glass, the blank image is formed on the blue background.
An HP sheet was obtained. No toner adhesion was observed on this OHP sheet.

When an image of the obtained OHP sheet was projected using OHP, it was a good image, and no decrease in brightness due to carbon toner was observed.

[0049]

According to the present invention, it is not necessary to use a dedicated OHP sheet forming machine, and it can be implemented by improving a general copying machine. In addition, the image formation of the OHP sheet
It can be carried out easily and at low cost, moreover, a large number of OHP sheets copied from one original can be obtained, and the original is not damaged.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a process of forming an image on an OHP sheet of the present invention.

FIG. 2 is a schematic view of a main part of an image forming apparatus for an OHP sheet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 OHP sheet 2 Infrared irradiation part 3 Toner removal part 4 Light-transmitting sheet 5 Thermosensitive layer 6 Release layer

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location 8305-2H B41M 5/26 A (72) Inventor Kaname Nakatani 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi Mitako (72) Inventor Yusuke Ishitani 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Engineering Co., Ltd.

Claims (6)

[Claims] 1. An OHP having a translucent sheet, a heat-sensitive layer provided on the translucent sheet and capable of discoloring at a predetermined temperature or higher, and a release layer provided on the heat-sensitive layer. Sheet. 2. The OHP sheet according to claim 1, wherein the release layer is a fluorine resin coating. 3. The OHP sheet according to claim 1, wherein the release layer is a silicone oil coating. 4. An image forming unit for forming a toner image on the OHP sheet according to claim 1, and an OH on which the toner image is formed.
An image forming apparatus using an OHP sheet, comprising: an infrared ray irradiating unit that changes the color of the thermosensitive layer of the OHP sheet where the toner image is formed by irradiating the P sheet with infrared rays. 5. The heat roller, wherein the infrared ray irradiating unit can transmit infrared rays, an infrared ray irradiating lamp arranged in the heat roller, and a pressure roller arranged so as to face the heat roller. The image forming apparatus according to claim 4, further comprising: 6. The image forming apparatus according to claim 4, wherein a cleaning device for removing the toner image on the OHP sheet is arranged on the side of the infrared irradiation unit in the conveying direction of the OHP sheet.