JPH10109774A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent adhesion of paper powder to a photosensitive drum surface so as to prevent generation of a stretch of an image by arranging a scraping member touching the transfer material surface just in front of transfer material feeding means and removing dust generated from the transfer material. SOLUTION: A brush type paper powder scraping member 17 is brought into contact with the surface on the uppermost side of a transfer material 5 set inside a paper feeding cassette 4 and is extended in the longitudinal direction over the width and more. The paper powder scraping member 17, which is always brought into contact with the longitudinal face of the transfer material 5 surface just before a paper feeding roller, is brought into contact with the surface of the transfer material 5 from the upstream side to the downstream side in the conveying direction when the transfer material 5 is fed. In this way, a filler with low adhesion or paper powder constructed of fine fiber, which penetrates the surface or the inside of the transfer material 5, is scraped off. By the time when the transfer material 5 is fed to a photosensitive drum 2, paper powder causing a stretch of an image is removed, so that generation of a stretch of an image can be prevented even at a high temperature and high humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system, and more particularly to a technique for cleaning a transfer material such as paper used in the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system, for example, a full-color printer is configured as shown in FIG.

More specifically, reference numeral 41 denotes a laser scanner unit which forms a laser beam on a sightseeing drum 42 and scans it to form a latent image on the photosensitive drum 42 by an ON / OFF signal from a laser driver 41a.

Reference numeral 43 denotes a developing rotary unit which accommodates developing cartridges of four colors of magenta, cyan, yellow and black.

Each developing cartridge is arranged with a certain gap (for example, 300 μm) on the photosensitive drum 42 during development. FIG. 4 shows this state.

The order of development is, for example, magenta, cyan, yellow, and black.

The developing rotary unit 43 rotates counterclockwise as shown by an arrow in FIG.

Before the latent image and developing steps described above are performed, a paper feeding and suctioning step is performed.

That is, the transfer material 45 such as paper stored in the paper feed cassette 44 temporarily stops while being sandwiched by the registration rollers 46.

Attraction roller 48 provided on transfer drum 47
As a result, static electricity is applied to the transfer drum 47, and the transfer material 45 passes between the transfer drum 47 and the attraction roller 48, then is electrostatically attracted and winds around the transfer drum.

At this point, the suction roller 48 separates from the transfer drum.

A tip sensor 55 is provided downstream of the registration roller 46 in the transfer material transport direction, and detects the length of the transfer material 45 passing therethrough in the transport direction.

Thereafter, the transfer material 4 wound around the transfer drum
5, a transfer is performed for each color in the order of magenta, cyan, yellow, and black, and a full-color image is formed by superimposing the colors.

In a conventional full-color printer, a combination of a photosensitive drum 42 having an outer diameter of 41 mm and a transfer drum having an outer diameter of 164 mm, which is four times the outer diameter which is an integral multiple of the photosensitive drum 42, has a full-color image throughput of 3 ppm. Is realized at a speed of 103 mm / sec.

When a full-color image is formed, the separation claw 4
As shown in FIG. 4, the transfer material 9 is brought into contact with the transfer drum 47 and the transfer process is completed. The transfer material is mainly subjected to a fixing process in a fixing unit 56 composed of a fixing roller 50 and a pressure roller 51. Done.

The fixing roller 50 of the fixing unit 56 is
The outer diameter is 40 mm, and an LTV silicon rubber layer having a thickness of 1.25 mm is formed on an aluminum core having a thickness of 2.7 mm. The pressure roller 51 has an outer diameter of 39.4 mm.
1.7mm thick on 2.2mm thick aluminum cored bar
5 and a halogen heater is built in both the fixing roller 50 and the pressure roller 51.

After the fixing step, the transfer cleaner unit 53 collects the toner remaining on the transfer drum 57 and cleans the transfer drum 57.

Further, the residual charge is removed by the charge removing roller 54. Through all the steps described above, a full-color image is formed on one sheet.

[0019]

The prior art described above has the following drawbacks.

In particular, when printing is performed in a high-temperature and high-humidity environment using a transfer material using talc as a filler, characters are partially blurred, and in severe cases, almost no image is printed. "Occurs.

This phenomenon is caused by the fact that the content of Mg contained in the transfer material /
Magnesium nitrate of low electric resistance activated by the reaction is ionized by AC charging of water as a medium,
What occurs on the photosensitive drum is a major factor.

The ease of occurrence of image deletion differs depending on the paper pulp material.

That is, domestic paper uses coniferous or hardwood wood as a pulp material, while Indian and Chinese papers use non-wood such as “kenaf” or “reed pulp” as a pulp material.

[0024] Non-wood includes "parenchyma" as compared to wood.
There are many round-shaped fibers called.

The "parenchyma" has a weaker bonding force between fibers than softwood or hardwood fibers used in domestic paper.
In addition, Indian and Chinese papers all contain talc as a filler.

For this reason, image deletion occurs more easily in Indian and Chinese papers than in domestic papers.

In order to prevent this inconvenience, a scraper made of a mylar sheet is brought into contact with a registration roller as a conventional technique to scrape off the paper dust adhering to the registration roller, and the scraped paper dust is applied to the back of the scraper. A method of collecting has been implemented.

However, the above-described method has the following problems. 1) Unless the contact of the scraper is uniform, the paper powder cannot be collected properly. 2) Since the scraper does not directly contact the transfer material, only the amount of paper powder attached to the registration roller can be collected. 3) Paper powder is composed of fine fibers of filler and transfer material, but those with a particle size of about 5 μm pass through the scraper and cannot be sufficiently removed.

[0029]

An image forming apparatus according to the present invention has been made in view of the above circumstances, and includes an image forming means for forming an image on a transfer material, and a transfer material fed to the image forming means. And a scraping member which is provided immediately before the feeding means and comes into contact with the surface of the transfer material to eliminate dust generated from the transfer material.

Further, another image forming apparatus according to the present invention comprises:
An image forming means for forming an image on a transfer material, a feeding means for feeding the transfer material to the image forming means, and a transfer material provided immediately after the feeding means A scraping member that comes into contact with the surface of the transfer material to eliminate dust generated from the transfer material.

Further, another image forming apparatus according to the present invention comprises:
In view of the above circumstances, an image forming means for forming an image on a transfer material, a feeding means for feeding the transfer material to the image forming means, and the transfer means provided immediately before the feeding means, A charging unit for charging dust generated from the material, a charging unit provided immediately after the feeding unit, a charge of a reverse load to the charging unit is applied, and a scraping member for removing dust on the surface of the transfer material is provided. It is characterized in that dust generated from the transfer material is eliminated.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION

<< Embodiment 1 >> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an image forming apparatus according to the present invention, and shows the configuration of a full-color printer as in FIG.

That is, reference numeral 1 denotes a laser scanner unit which forms a laser beam on the sightseeing drum 2 and scans it to form a latent image on the photosensitive drum 2 by ON / OFF signals from the laser driver 1a.

Reference numeral 3 denotes a developing rotary unit, which accommodates developing cartridges of four colors of magenta, cyan, yellow, and black.

Each developing cartridge is arranged with a certain gap (for example, 300 μm) on the photosensitive drum 2 during development.

The order of development is, for example, magenta, cyan, yellow, and black.

The developing rotary unit 3 rotates counterclockwise as indicated by the arrow in FIG.

Before the latent image and developing steps described above are performed, a sheet feeding and suctioning step is performed.

That is, the transfer material 5 such as paper stored in the paper cassette 4 temporarily stops while being sandwiched between the registration rollers 6.

A static electricity is applied to the transfer drum 7 by an attraction roller 8 provided on the transfer drum 7, and the transfer material 5 passes between the transfer drum 7 and the attraction roller 8, and then is electrostatically attracted to the transfer drum 5. Wrap around.

At this point, the suction roller 8 separates from the transfer drum.

A tip sensor 15 is provided downstream of the registration roller 6 in the transfer material transport direction, and detects the length of the transfer material 5 passing therethrough in the transport direction.

Thereafter, the transfer material 5 wound around the transfer drum
On the upper side, transfer is performed for each color in the order of magenta, cyan, yellow, and black, and a full-color image is formed by overlapping the colors.

When a full-color image is formed, the separation claw 9
The transfer material that has completed the transfer process by contacting with the transfer drum 7 is subjected to a fixing process mainly in a fixing device unit 16 including a fixing roller 10 and a pressure roller 11.

After the fixing process is completed, the transfer cleaner unit 13 collects the toner remaining on the transfer drum 17 and cleans the transfer drum 17.

Further, the residual charge is removed by the charge removing roller 14. Through all the steps described above, a full-color image is formed on one sheet.

The configuration so far is not different from the above-mentioned conventional full-color printer.

In FIG. 1, reference numeral 17 denotes a brush-shaped paper dust scraping member on which countless straight 10 μm bristles are planted, and the uppermost member of the transfer material 5 set in the paper feed cassette 4. Contacting the transfer material surface.

The brush-shaped paper dust scraping member 17 extends in the longitudinal direction (perpendicular to the drawing) over the width of the transfer material, and comes into contact with the surface of the transfer material surface in the longitudinal direction. ing.

The brush-shaped paper dust scraping member 17 is always in contact with the surface of the transfer material in the longitudinal direction in front of the paper feed roller. From the upstream side to the downstream side in the transport direction, which moves when the paper is fed from the printer, the paper comes into contact with the surface of the transfer material 5.

As a result, paper powder composed of fillers and fine fibers having low adhesion to the transfer material 5 sunk into the surface or inside of the transfer material is scraped off. It is also possible to scrape off the filler having a particle size of about 5 μm attached to one transfer material 5 or one transfer material.

Therefore, when the transfer material 5 is conveyed to the photosensitive drum, the paper dust causing the image deletion is removed, and it is possible to prevent the occurrence of the problem of image deletion even under high temperature and high humidity.

Second Embodiment FIG. 2 shows a second embodiment of the present invention, in which a fur brush is provided immediately after a paper feed roller.

Reference numeral 18 denotes a fur brush that contacts the imprinted ground side of the transfer material 5, and 19 denotes a fur brush that contacts the non-imprinted ground side of the transfer material 5.

Since these are positioned so as to sandwich the transfer material 5, they also have a role of transporting the transfer material 5.

Reference numeral 20 denotes a scraping blade provided on the fur brush 18, and reference numeral 21 denotes a filter for collecting paper dust scraped off by the fur brush 18 and the scraping blade 20.

The fur brushes 18 and 19 rotate in the direction of the arrow while in contact with the transfer material. By cleaning the surface of the transfer material, the fillers and fine fibers having a weak adhesive force adhere to the transfer material 5. The paper powder composed of is recovered.

Therefore, when the transfer material 5 is conveyed to the photosensitive drum 2, the paper dust causing the image deletion is removed, and the problem of image deletion can be prevented even under high temperature and high humidity.

Embodiment 3 FIG. 3 shows Embodiment 3 of the present invention, in which a charging roller is provided immediately before a paper feeding roller, and a fur brush is provided immediately after the paper feeding roller. Is arranged.

In FIG. 3, reference numeral 22 denotes a charging roller.
A positive bias is applied to the metal core from the power supply 23 while being in contact with the surface of the transfer material 5.

The opposing pole of the charging roller 22 is grounded to the frame ground of the main body via the metal part of the sheet cassette 4.

The charging roller 22 can be moved in the height direction of the paper feed cassette 4 in accordance with the state of the transfer material 5 in the thickness direction. Contacting the transfer material.

Reference numeral 24 denotes a fur brush which comes into contact with the printing surface of the transfer material 5, and is made of a conductive material. A negative bias is applied to the core of the fur brush 24 from a power supply 25. This counter electrode is also grounded to the frame ground of the main body.

Reference numeral 26 denotes a fur brush which comes into contact with the non-printing surface of the transfer material. Reference numerals 24 and 26 are disposed opposite to each other with the transfer material interposed therebetween, and the fur brushes 24 and 26 come into contact with the transfer material. During this period, the transfer material 5 rotates in the direction of the arrow, and thus plays a role of transporting the transfer material 5.

Reference numeral 27 denotes a scraping blade provided on the fur brush 24, and reference numeral 28 denotes a filter for collecting paper dust scraped off by the fur brush 24 and the scraping blade 27.

In the third embodiment constructed as described above, the charging roller 19 first increases the surface of the transfer material 5 when the transfer material 5 starts to move from the paper feed cassette 4 and starts moving. Charge.

By this operation, the paper dust is positively charged.

Fur brush 24 to which minus is applied
Collects paper dust on the surface of the transfer material that is positively charged.

Therefore, when the transfer material 5 is conveyed to the photosensitive drum 2, the paper dust causing the image deletion is removed, and the occurrence of the problem of image deletion even under high temperature and high humidity can be prevented.

[0071]

As described above, according to the present invention, 1) by providing a paper dust scraping member on a brush, which is disposed near the paper feed roller of the apparatus main body and is in contact with the surface of the transfer material, Paper dust adhering to the transfer material surface can be scraped off,
Since paper dust is not attached to the surface of the photosensitive drum, it is possible to prevent the occurrence of image deletion. 2) By providing a scraping member provided immediately after the transfer material feeding means and in contact with the surface of the transfer material, paper dust adhered to the surface of the transfer material can be scraped, and paper dust adhered to the surface of the photosensitive drum. Is not attached, so that it is possible to prevent the occurrence of image deletion. 3) a charging means provided immediately before the transfer material feeding means and charged to dust generated from the transfer material; and a charging means provided immediately after the feeding means and having a load opposite to that of the charging means, By providing a scraping member for removing dust on the surface of the transfer material, paper dust attached to the surface of the transfer material can be scraped, and paper dust does not adhere to the surface of the photosensitive drum. Has the effect that it becomes possible to prevent

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a full-color printer according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a full-color printer according to a second embodiment of the invention.

FIG. 3 is a diagram showing a configuration of a full-color printer according to Embodiment 3 of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional full-color printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter scanner unit 1a Laser driver 1a 2 Sightseeing drum 3 Developing rotary unit 4 Paper feed cassette 5 Transfer material 6 Registration roller 7 Transfer drum 8 Suction roller 9 Separation claw 10 Fixing roller 11 Pressure roller 12 Discharge roller 13 Transfer cleaner unit Reference Signs List 14 suction roller 15 tip sensor 16 fixing device unit 17 paper powder scraping member 18 fur brush 19 fur brush 20 scraping blade 21 filter 22 charging roller 23 power supply 24 fur brush 25 power supply 26 fur brush 27 scraping blade 28 filter

Claims (10)

[Claims] An image forming unit that forms an image on a transfer material; a feeding unit that feeds the transfer material to the image forming unit; a feeding unit that is provided immediately before the feeding unit and contacts a surface of the transfer material. An image forming apparatus, comprising: a scraping member for removing dust generated from the transfer material. 2. The image forming apparatus according to claim 1, further comprising a stacking unit for stacking the transfer material, wherein the scraping member is disposed so as to come into contact with an uppermost transfer material stacked on the stacking unit. The image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein the scraping member has a brush shape. 4. The image forming apparatus according to claim 1, wherein said image forming means forms an image by an electrophotographic method. 5. An image forming means for forming an image on a transfer material, a feeding means for feeding the transfer material to the image forming means, and provided immediately after the feeding means and in contact with the surface of the transfer material. An image forming apparatus, comprising: a scraping member for removing dust generated from the transfer material. 6. The image forming apparatus according to claim 5, wherein two of the scraping members are disposed to face each other with the transfer material interposed therebetween, and each of the scraping members has a fur brush shape. 7. An image forming apparatus according to claim 5, wherein said image forming means forms an image by an electrophotographic method. 8. An image forming means for forming an image on a transfer material, a feeding means for feeding the transfer material to the image forming means, and a dust provided immediately before the feeding means and generated from the transfer material. A charging means provided immediately after the feeding means, and a charge opposite to the charging means is applied, and a scraping member for removing dust on the surface of the transfer material is provided. An image forming apparatus characterized by removing dust generated. 9. The image forming apparatus according to claim 5, wherein two of the scraping members are disposed to face each other with the transfer material interposed therebetween, and each of the scraping members is in the form of a fur brush. 10. An image forming apparatus according to claim 5, wherein said image forming means forms an image by an electrophotographic method.