JPH06308421A - Image reader using optical member with dustproofing coat - Google Patents

Abstract

PURPOSE:To prevent dust, dirt or the like from being attached on the surface of an optical member and to effectively prevent light quantity from being lowered caused by the effect of the dust or the like by coating the surface of at least one optical member out of the optical members with fluoric oil preventing the dust from being attached on the surface. CONSTITUTION:An illumination means 10 is constituted of a light source 1 and a reflector 2. By reflecting mirrors 5a-5c, a luminous flux reflected from an original 3 is made incident on an image forming optical system 6. Then, image information is formed on the surface of a photosensitive drum 8 through a reflecting mirror 5d and a transparent glass for dustproofing 7. The respective reflecting surfaces of the mirrors 5a-5d are coated with the fluoric oil and a film for lowering the frictional force of the surface is formed. As a method that the reflecting surface is coated with the fluoric oil, the small quantity of fluoric oil is dropped on the reflecting surface and the excess oil left on the reflecting surface is wiped while it is made thin by a soft cloth such a chamois thereafter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus using an optical member provided with a dustproof coat, and more particularly, to a surface of at least a part of an optical member constituting an optical system for reading an image, a dustproof coat made of fluorine-based oil or the like. The present invention relates to an image reading apparatus using an optical member with a dustproof coating, which is suitable for, for example, a copying machine or the like, by applying dust to prevent dust and the like from adhering to the surface and enabling highly accurate image reading.

[0002]

2. Description of the Related Art Conventionally, the structure of an image reading apparatus such as a copying machine has a structure as shown in FIG. Figure 2
In the above, the surface of the manuscript 23 is illuminated by the illuminating means 30, and the luminous flux reflected from the surface of the manuscript 23 is sequentially reflected by the reflecting mirror 25.
The optical path is bent through a, 25b, and 25c, and the light is focused by the imaging optical system 26. Then, the light flux from the imaging optical system 26 is imaged on the surface of the image carrier such as the photoconductor 28 via the reflection mirror 25d and the transparent glass 27. Along with this, the image reading line (document surface) is moved in the sub-scanning direction to record or read image information on the surface of the document 23.

In the image reading apparatus of this type, one of the causes for decreasing the amount of light incident on the image carrier surface 28, that is, the amount of exposure.
Finally, there is dirt on the surface of each optical member constituting the optical system.

This is because dust or the like in the air naturally falls inside the apparatus and adheres to the surface of each optical member.

For example, a plurality of reflection mirrors (optical path bending mirrors) having glass substrates arranged in the optical path of an optical system
Taking 25a to 25d as an example, dust or the like in the air inside the apparatus spontaneously falls and adheres to the reflecting surfaces (surfaces) of the reflecting mirrors 25a to 25d while the copying machine is stopped. was there.

During the copying operation of the copying machine, the cooling fan disturbs the cold air containing dust, and in particular, a large amount of dust adheres to a part of the reflecting surface facing upward with respect to the apparatus. There was something that happened.

This is because dust or the like having an electric charge is adsorbed to the reflecting surface (surface) due to static electricity, or the fine frictional surface of the reflecting surface causes surface frictional force to catch the dust or the like in contact. ing. This was almost the same for the other optical members constituting the optical system.

[0008]

If dust or the like adheres to the reflection surfaces (surfaces) of the reflection mirrors 25a to 25d as the optical path bending means 25 shown in FIG. 2, the reflection is caused by the influence of the dust and the like. A part of the light flux is shielded by the surface, the reflectance is reduced, and the amount of reflected light is reduced. As a result, there is a problem in that a copy (copy) is output as a defective image such as a fog.

On the surface of an optical member such as a transparent lens which constitutes the image forming optical system 26 and a transparent glass 27 for dust prevention, especially electrostatic dust tends to adhere to the surface of the optical member. Due to such influences, a part of the light flux is shielded, the transmittance is lowered, and the amount of transmitted light is reduced.

In the market, in order to compensate for the decrease in light quantity due to the influence of dust etc., for example, a light source (lamp) as an illumination means.
The lighting voltage is increased to increase the amount of illumination light.

However, as this adverse effect, a new problem occurs such that the lighting life of the lamp is significantly reduced.

Therefore, in a conventional image reading apparatus such as a copying machine, it is necessary to open the inside of the apparatus and periodically clean the surface of the optical member on which dust or the like is attached. The cleaning at this time is generally troublesome.

Of the optical members constituting the optical system for image reading according to the present invention, the reflective optical member is coated with a dust-proof coating such as fluorine oil to reduce the frictional force on the surface and is transparent. Regarding the optical member, a conductive film is applied to the surface of the optical member, and a film that reduces the frictional force is formed on the surface of the optical member to prevent dust and dust from adhering to the surface of the optical member. An object of the present invention is to provide an image reading apparatus that effectively prevents a decrease in the amount of light due to the influence of the light source and prevents a reduction in the life of the light source, and uses an optical member with a dust-proof coating suitable for an image reading apparatus such as a copying machine.

[0014]

An image reading apparatus using an optical member with a dustproof coating according to the present invention includes an optical member that illuminates a document with a light beam emitted from a light source and reflects or transmits the light beam from the document. A fluorine-based oil that prevents dust from adhering to the surface of at least a part of the optical members when the image information is read on the original surface by the projection system via the projection system. It is characterized by being applied.

[0015]

FIG. 1 is a schematic view of an essential part of an optical system of Embodiment 1 when the present invention is applied to an image reading apparatus of a copying machine.

In the figure, 1 is a light source, which is composed of, for example, a halogen lamp. Reference numeral 2 denotes a reflecting mirror (reflecting shade) for illuminating the original, which is made of aluminum as a substrate, and collects a light beam emitted from the light source 1 in the direction opposite to the original 3 surface and returns it to the side of the light source 1 to return to the original 2 surface. Lighting efficiency. It should be noted that the light source 1 and the reflection shade 2 constitute the illuminating means 10.

A document 3 is placed on the document table 4. Reference numerals 5a to 5d are reflection mirrors (optical path bending mirrors) that form the optical path bending means 5, and are made of a glass substrate. The reflection mirrors 5 a to 5 c bend the optical path by reflecting the reflected light beam from the original 3 and make it enter the imaging optical system 6. Then, the imaging optical system 6 guides the light onto the surface of the photosensitive drum 8 as an image carrier through the reflection mirror 5d and the transparent glass 7 for dust prevention, and forms image information on the surface.

Each of the reflecting mirrors 5a to 5d in this embodiment.
Forms a film that reduces the frictional force of the surface by coating the reflective surface (surface) with a fluorine-based oil such as demnum (registered trademark: Daikin Industries, Ltd.).

The image forming optical system 6 has a plurality of transparent lenses, and forms a light beam based on image information from the original 3 on the surface of the photosensitive drum 8 at a predetermined magnification. The transparent glass 7 is made of a flat surface.

In the present embodiment, the image on the surface of the original 3 illuminated by the luminous flux from the illumination means 10 is reflected by the reflecting mirrors 5a, 5a.
The reflecting mirror 5d is formed by the imaging optical system 6 via b and 5c.
An image is formed on the surface of the photosensitive drum 8 through the transparent glass 7. Next, the surface of the original 3 is moved in the sub-scanning direction to sequentially record the image information on the surface of the original 3.

Generally, a reflection mirror (optical path bending mirror) used in an image reading apparatus such as a copying machine is often formed by using glass as a substrate and coating the reflection surface with aluminum.

In the present embodiment, the aluminum-coated reflecting surface (surface) is treated with a fluorine-based oil, demnum (registered trademark: Daikin Industries, Ltd.), which reduces the frictional force of the surface. A film is formed to reduce the frictional force. This prevents dust and the like from adhering to the reflecting surface when the reflecting mirror is arranged so that the reflecting surface is in an obliquely upward posture.

As a method of applying this fluorine-based oil to the reflecting surface, for example, a small amount of fluorine-based oil is dropped on the reflecting surface, and then it is left on the reflecting surface while being thinly spread with a soft cloth such as seine (cleaning means). Wipe off excess oil. Alternatively, apply a small amount of fluorine-based oil to the cloth beforehand and apply a reflective surface while spreading it thinly,
After that, you may wipe it off with a dry cloth.

At this time, if a little fluorine-based oil remains on the reflecting surface, the reflecting surface becomes new dirt. Therefore, the fluorine-based oil is completely removed by the cleaning means. Further, this wiping operation (cleaning means) may be automatically performed by using another technique.

Next, a second embodiment of the present invention will be described.

In the present embodiment, the fluorine-based oil is applied to the reflecting surface (surface) of the reflecting mirror (reflecting shade) 2 for illuminating the original, which is made of a metal such as aluminum as a substrate, as in the first embodiment. , Forming a film that reduces the frictional force on the surface.
This prevents a decrease in the amount of light emitted from the illumination means 10 and achieves the same effects as those of the first embodiment.

As described above, in the first and second embodiments, the reflection surface (surface) of the reflection shade 2 and the reflection mirrors 5a to 5d for bending the optical path is coated with fluorine-based oil to reduce the frictional force on the surface. It forms a film that lowers. When dust and the like come into contact with the reflection shade 2 and the reflection mirrors 5a to 5d during the natural fall, most of them slide off from the surface so that dust and the like do not adhere to the reflection surface. The reduction of the reflected light quantity and the irradiation light quantity is prevented.

Further, since electrostatically charged dust or the like also uses an aluminum material for the reflecting surface, the charge escapes at the moment when the dust or the like comes into contact with the reflecting surface, and the attracting force is lost. To prevent adhesion.

As described above, in Examples 1 and 2, it is possible to prevent a decrease in the reflectance of each reflecting surface over a long period of time, which effectively prevents the occurrence of defective images and periodically. The frequency of cleaning is also reduced.

Next, a third embodiment of the present invention will be described.

In this embodiment, first, a conductive coat such as EC coat or cor coat is applied on the surface of the transparent glass 7 which is a flat surface as an optical member and dried, and then the above-mentioned film is formed on the film. As in Examples 1 and 2, fluorine-based oil is applied to form a film for reducing the frictional force on the surface. As a result, for example, dust having electrostatic force is prevented from adhering to the surface thereof, and the dust is prevented from adhering due to frictional force to prevent the amount of passing (transmitted) light from decreasing.

Next, a fourth embodiment of the present invention will be described.

In this embodiment, a conductive coat is first applied to at least one lens surface (front surface) of a plurality of transparent lenses constituting the image forming optical system 6 in the same manner as in the third embodiment. After drying, a fluorine-based oil is applied onto the film in the same manner as in Examples 1 and 2 described above, and the same effect as in Example 3 is obtained.

As described above, in Examples 3 and 4, the adhesion of static electricity and the like is prevented by the conductive coat applied to the surface of the glass or the lens, and the adhesion of dust and the like due to the frictional force. In the same manner as in the first and second embodiments described above, this is prevented by applying the fluorine-based oil from above the conductive film.

In the above-mentioned Examples 1 to 4, the surface of some of the optical members constituting the optical system was coated with fluorine oil or a combination of fluorine oil and a conductive coat. Of course, the surface of all of these optical members may be applied with a fluorine-based oil or a combination of a fluorine-based oil and a conductive coat.

According to this, the exposure can be performed without lowering the amount of light incident on the surface of the photosensitive drum, that is, the amount of exposure, and a more excellent copied image can be obtained.

Further, in the first to fourth embodiments, the example in which the present invention is applied to the image reading device of the copying machine is shown, but of course the present invention is applied to other image reading devices such as a facsimile and an image scanner. Can be applied.

[0038]

As described above, according to the present invention, a film for reducing the frictional force is formed on the surface of the reflective optical member of the optical member constituting the optical system by using fluorine oil and is transparent. A conductive film is applied to the surface of a transparent optical member, and a film that reduces the frictional force is formed on the film by using fluorine-based oil to prevent the occurrence of defective images and the shortening of the life of the light source. It is possible to achieve an image reading apparatus using an optical member with a dustproof coating, which is suitable for an image reading apparatus such as a copying machine, which can reduce the frequency of regular cleaning.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of an optical system according to a first embodiment when the present invention is applied to an image reading device of a copying machine.

FIG. 2 is a schematic view of a main part of an optical system of a conventional image reading device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Reflector 3 Original 4 Original table 5 Optical path bending means 5a, 5b, 5c, 5d Reflecting mirror 6 Imaging optical system 7 Transparent glass 8 Image carrier 10 Illuminating means

Claims (7)

[Claims] 1. A document is illuminated with a light beam emitted from a light source, and is guided to an image carrier by a projection system through an optical member that reflects or transmits the light beam from the document to read image information on the surface of the document. At this time, an image reading apparatus using an optical member with a dust-proof coating, characterized in that at least a part of the optical member is coated with a fluorine-based oil for preventing dust from adhering to the surface thereof. . 2. An optical element with a dust-proof coating according to claim 1, further comprising a cleaning means for removing the oil remaining on the surface of the optical member after the fluorine-based oil is applied on the surface of the optical member. Image reading device using a member. 3. An optical element with a dustproof coat according to claim 1, wherein a conductive coat is applied to the surface of the optical member, and the fluorine-based oil is applied to the surface of the conductive coat. Image reading device using a member. 4. The image reading apparatus using the optical member with a dustproof coat according to claim 1, wherein the optical member is a reflecting mirror that uses aluminum as a substrate and reflects a light beam from the light source. 5. The image reading apparatus using the optical member with a dustproof coat according to claim 1, wherein one of the optical members is a reflection mirror having a glass substrate that reflects a light beam from the light source. 6. The image reading apparatus using the optical member with a dustproof coat according to claim 3, wherein one of the optical members is a transparent glass having a flat surface. 7. The image reading apparatus using the optical member with a dustproof coat according to claim 3, wherein one of the optical members is a transparent lens.