JPH0318861A - Transparent film and detection of transparent film - Google Patents

Abstract

PURPOSE:To allow the decision of the front and rear of the transparent film by providing opaque parts asymmetrically with the mid-point of at least one side of the rectangular film along the outer periphery of this side of the film. CONSTITUTION:The opaque parts 2 consist of printing, or sticking of paper, cloth, etc., which absorb or reflect the wavelength of a light source used for an optical sensor by a prescribed quantity or above and are provided in the shape to be asymmetrical laterally with the mid-point of one side of the film 1 continuously or discontinuously along this side. The opaque parts 2, therefore, disappear in the sensor part 31 when the film 1 is reversed laterally, turned back and fed with an electrophotographic device which has the transporting path to be a one side basis for a transfer material 34 with respect to a center line 32 and is installed with the optical sensor 31 for detecting the transfer material on one side. The front and rear of the film 1 are surely detected in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transparent film on which a toner image is formed by electrophotography or electrostatic recording, and a method for detecting this transparent film.

[Prior Art] Conventionally, it has been common practice to form a monochromatic toner image on a film made of transparent polyester or the like using an electrophotographic device, and then subject the resulting image to an OHP (over-hard projector) or the like to use it as a projected image. It is.

In recent years, in electrophotographic apparatuses, a transmission type light sensor using a light source such as an LED or a reflection type optical sensor has been used as means for detecting the running of a recording material due to cost and detection accuracy.

The emission wavelength of light sources such as LEDs is from visible light to infrared light, so when a transparent film such as polyester as mentioned above is used as a recording material, it is difficult to absorb or reflect the light from the LED, making it difficult to detect. becomes impossible,
For this reason, proposals have been made to provide a part of the transparent film with an opaque member that absorbs or reflects light from LEDs, etc.
This method is disclosed in Japanese Unexamined Patent Publication No. 59-7367.

This material can be printed with paint that cuts the amount of light from the LED light by 60% or more, or it can be made by pasting paper, cloth, etc. in the form of a strip on top of the film, or it can also be used to block infrared light-emitting type LEDs used in boat fishing. Detection is possible by forming a vapor-deposited metal film that can
As shown in the figure, the aforementioned opaque portion is uniformly formed as a band having a constant width along the outer periphery of one or more sides of the rectangular film. Furthermore, as proposed in Japanese Patent Application Laid-Open No. 58-106550, a plurality of opaque parts are formed by forming a plurality of opaque parts in FIGS.
As shown in h), there is a proposal to provide the film on a transparent film so that the location where the film is clogged can be easily confirmed in the event of a running accident inside a copying machine.

In addition, transparent films used in recording devices such as electrophotographic devices are coated with transparent resin to improve the adhesion of fixed toner and to improve translucency and color reproducibility. The present inventor has previously proposed the use of transparent films with different functionalities on the front and back surfaces, such as coating a transparent film with a color toner image and forming a color toner image on the surface.

When using recording materials with different surface properties on the front and back sides,
Since the operator may mistake the front and back sides of the recording material, it is preferable to detect the front and back sides and issue a warning or stop the apparatus if it is the back side.

[Problems to be solved by the invention] However, in the shape of the light shielding part provided on the outer periphery as shown in FIG. It will be difficult to do so. Also, in the case of Fig. 2 (b), when paper is fed in the direction of the arrow, front and back detection is performed at the edge of the transparent film, which may result in failure to detect or false detection due to misalignment of the paper feeding position or misalignment of the optical sensor. There is a big possibility.

Furthermore, if an attempt is made to provide the same function on both sides of the transparent film in order to prevent this, the cost will be higher than that on one side.

[Means for Solving the Problems] The present invention for solving the above problems has the following features: along at least one side,
A method for detecting a rectangular transparent film in a recording device having a rectangular transparent film characterized by having an opaque portion asymmetrical with respect to the midpoint of this side, a light source for detecting a recording material, and a light receiving portion, at least This method of detecting a transparent film is characterized in that the front and back sides of the transparent film are determined based on the output from the light receiving section while the transparent film having an opaque part asymmetrical with respect to the midpoint of the side is being conveyed along one side.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIGS. 1(a) to 1(c) are plan views showing a transparent film according to an embodiment of the present invention, and FIG. 1(d) is a sectional view.

In the figure, 1 is a transparent film, 2 is an opaque portion, and 3 is a functional surface portion made of transparent resin for improving image quality.

The transparent film 1 is a heat-resistant resin film having a maximum operating temperature of too much or more, and is made of, for example, polyester, polyamide, polyimide, or the like. Particularly, polyethylene terephthalate (PET) is preferable from the viewpoint of heat resistance and transparency. Regarding the thickness, it is necessary to have a thickness of 50 μm or more so that wrinkles etc. do not occur due to heating during fixing, and a thickness of 200 μm or less is preferable to ensure transparency.

As shown in FIGS. 1(a) to (C), the opaque part 2 is made of a material that absorbs or reflects 60% or more of the wavelength of the light source used for the optical sensor, and is printed or pasted with paper or cloth, and has a shape that As shown in the figure, it is sufficient that they are provided continuously or discontinuously along one side of the film and in a shape that is left-right asymmetrical with respect to the midpoint of the provided side.Furthermore, the position where the opaque portion is provided. It suffices if they are provided to match the position of the optical sensor in the machine (combination of light source and phototransistor), and if there is an even number of optical sensors in the electrophotographic device, their positions should match the position of the transfer material. 3 is a coating film for imparting functionality to the transparent film, and although it is provided on the same surface as the opaque part 2 in the figure, it should not be symmetrical with respect to the center of the transport path. There is no problem in that aspect. Further, different functional surfaces may be provided on both sides.

The above-mentioned functionality imparted to the transparent film includes l) control of the surface resistance value of the transparent film, 2) control of the surface frictional force of the transparent film, 3) provision of fixing properties for toner on the transparent film, and 4) provision of toner fixability on the transparent film. The color reproducibility of the formed color toner image when transmitted through light can be improved. Further, other physical and chemical functions are also within the scope of the present invention, provided that the front and back sides of the film are different from each other.

Next, embodiments of the present invention will be described in detail.

A solution prepared by dissolving polyester resin A (solubility parameter approximately 11.0) in acetone and having a melt viscosity of 20 x 10' voids at 130 °C was coated on one side of a PET film with a thickness of 100 μm and a continuous use temperature of 150 °C using a bar coater method. An overcoat layer was formed to have a thickness of 16 μm after drying to obtain a transparent laminate film. This lamination improves the color reproducibility of the color toner image when it is transmitted through light.

Furthermore, on the two sides of the opposite side of this top coat layer, as shown in Fig. 1(a)
As shown in the shaded area, the desired film was formed using an ultraviolet curing black acrylic paint that can block 80% or more of infrared light with a wavelength of 800 to 11,000 nm. The size of the film was A4 size.

The center line 32 of the film as shown in FIG. 3(a)
The transfer material 34 has a transport path with one side as a reference, and the optical sensor 31 for detecting the transfer material is installed on one side with respect to the center line 35 of the smallest size transfer material. Paper was fed into the electrophotographic apparatus in the direction of both arrows so that arrow A in FIG. 1 and arrow 33 in FIG. 3 coincided.

Note that toner image formation was performed on the top coat layer.

The toner used is a yellow toner that exhibits sufficient compatibility with the above-mentioned overcoat layer in a molten state during fixing.

When the paper was fed according to the example, image formation was performed without any problems, and the resultant transparent film was viewed as a translucent image using an OHP (overhead projector).
A bright yellow image was obtained.

When the above-mentioned film was reversed from left to right with respect to arrow A, and the paper was fed inside out, in this case, there was no opaque part 2 in the sensor 31 section, and one of the sensors determined whether it was front or back, and the machine was automatically activated before image formation. This can prevent image formation from occurring without using the functions provided to the transparent film.

Note that the opaque portion preferably cuts or reflects 60% or more of the light from the light source.

On the other hand, when a conventional transparent film having an opaque portion of the type shown in FIGS. 2(a) to 2(d) is used, it is difficult to prevent the above-mentioned accidents from occurring.

FIGS. 1(b) and 1(C) are views showing other embodiments of the transparent film of the present invention, and the shapes of the opaque portions are different from those in FIG. 1(a).

In the case of FIG. 1(b), there are two opaque areas indicated by diagonal lines, and sensor positions within the electrophotographic apparatus are provided correspondingly. In the type (C), printing is continuous, but asymmetrical portions with respect to the center line 5 exist on the sides perpendicular to the center line 5. In this case, the sensor will be placed at a position that matches the middle position.

Further, in the above-mentioned embodiments, the transfer paper is conveyed using a conveyance system based on one side, but there is no problem in using a conveyance system based on the center as shown in FIG. 3(b).

In addition, in FIGS. 1A to 1C, opaque portions are provided along two orthogonal sides.

Therefore, the transport direction of the transparent film is the horizontal direction.

It is possible to distinguish between front and back sides regardless of whether it is in the B direction.

Further, the opaque portion according to the present invention is applicable not only to the transparent film having the above-mentioned structure, but also to all light-transmitting films, such as those having a structure such as label paper, which is a combination of release paper and adhesive paper.

[Effects of the Invention] As described above, according to the present invention, it is possible to reliably detect the front and back sides of a transparent film.

[Brief explanation of the drawing]

FIGS. 1(a) to (C) are plan views of transparent films according to embodiments of the present invention, FIG. 1(d) are cross-sectional views of transparent films according to embodiments of the present invention, and FIGS. 2(a) to 2(c) are respectively (+) is a plan view of a conventional transparent film, and FIGS. 3(a) and 3(b) are diagrams showing the relative positions of the transparent film and the optical sensor according to the present invention. In the figure, 1 is a transparent film base 2 is an opaque part 3 is a coating layer 5 is a film center line 31 is a photosensor position 30 (θ)

Claims (4)

[Claims] (1) A rectangular transparent film characterized by having an opaque portion along at least one side that is asymmetrical with respect to the midpoint of this side. (2) The transparent film according to claim 1, wherein the front and back surfaces have different surface properties. (3) In a method for detecting a rectangular transparent film in a recording device having a light source and a light receiving section for detecting a recording material, the transparent film has an opaque portion asymmetrical with respect to the midpoint of the side along at least one side. A method for detecting a transparent film, characterized in that the front and back sides of the transparent film are determined based on the output from the light receiving section during transportation. (4) The opaque part absorbs 60% of the light from the detection light source.
4. The method for detecting a transparent film according to claim 3, wherein the transparent film is cut or reflected.