JPH0656301A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device equipped with a static eliminator whose constitution is simple and which can be easily mounted. CONSTITUTION:A paper sheet guiding section 19 comprises a paper sheet carrying guide table 41 and a plurality of ribs 49 for guiding paper sheets with a specified gap formed between the paper sheet attached to the guide table 41 and the guide table 41, and a static eliminator 31 is a static eliminator sheet secured and fixed to the guide 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a laser system and an LED.
The present invention relates to an optical printer such as a (light emitting diode) type or a liquid crystal type, or an image forming apparatus such as a copying machine, and in particular, an electrostatic charge eliminator for removing an electrostatic charge of a sheet on which a toner image is transferred from a photoconductor. It relates to an improved configuration.

[0002]

2. Description of the Related Art An image forming apparatus has a structure as shown in FIG. First, there is a cassette 101,
A plurality of sheets 103 are stored in the cassette 101 in a stacked state. The paper 103 is conveyed to the conveyance path 107 by the paper feed roller 105. The conveyed sheet 103 has a pair of registration rollers 109, 1
It is sent toward the photoconductor (photosensitive drum) 111 through the gap 09 '. A toner image is formed on the photoconductor 111, and the sheet 103 is conveyed so as to contact the photoconductor 111. At this time, the transfer charger 113 applies a charge having a polarity different from that of the toner from the back side of the sheet 103. As a result, the toner is attracted to the paper 103, and the toner image is transferred to the front side of the paper 103.

The sheet 103 on which the toner image has been transferred passes over the static eliminator brush 115 as a static eliminator and a conveyance guide section 117, and a pair of fixing rollers 119,
Sent during 119 '. At that time, the toner image is printed on the paper 1.
It will be fixed on the front side of 03. The sheet 103 on which the image is fixed passes through between the pair of sheet discharge rollers 121 and 121 ′ and is accommodated in the sheet discharge tray 123.

The structure of the transport guide section 117 is as follows.
For example, there is one as shown in FIG. FIG. 9 is a perspective view showing a configuration of the transport guide unit 117. First, there is a transport guide base 125 made of a metal plate. The transport guide base 125 has a plurality of ribs 127 at predetermined intervals. Installed. The plurality of ribs 127 are plastic parts that are integrated via a connecting portion 128. Such a plastic part is used for the transport guide base 12
5 is fitted from the lower side in the drawing, and the rib 127 is fixed in a state of protruding from the slit 126 formed in the transport guide base 125. That is the state shown in FIG. A groove 129 is bent at the left end portion of the conveyance guide base 125 in the figure.
The discharge wire 130 is formed in the groove 129.
Is stretched. The transport guide base 125 is electrically grounded, and the discharge wire 130 and the groove 29 constitute a transfer charger 113.

[0005]

The above-described structure has the following problems. First, the sheet 103 is charged by the transfer charger 113 when the toner image is transferred, and when the sheet 103 recorded in that state is discharged, when the sheet 103 is stacked on the discharge tray, the sheets 103 repel each other. If it does not fit well, it may not be aligned, or recording paper (paper 103)
There is a problem that the charged electric charges of (1) are discharged to the human body to give a shock, or the hair is sucked to give an unpleasant feeling.
Further, the conveyance guide base 125 electrically sucks the charged recording paper (paper 103) and conveys the recording paper (paper 103) along the surface of the rib 127. When the amount is excessive, an arc discharge phenomenon occurs between the recording paper (paper 103) and the facing surface of the conveyance guide base 125, and the discharge causes an unfixed toner image on the surface of the recording paper (paper 103). There was a problem of being disturbed. In particular, the transport guide base 125 and the recording paper (paper 10
This phenomenon frequently occurs in the vicinity of the rear end of the conveyance guide where the facing distance of 3) sharply separates. Further, simply recording paper (paper 10
In order to eliminate the electrostatic charge of 3), it is generally practiced to dispose an antistatic brush in the rear stage of the fixing device or the like.
In the case of the structure in which the transfer charger and the conveyance guide in the subsequent stage are connected as described above, the space for installing the static elimination brush is insufficient or has a complicated structure.
There is also a problem that the cost is inevitably high.

The present invention has been made on the basis of such a point, and its object is to have a simple structure and a simple mounting operation, and to be arranged in a sheet conveying path after transfer. Equipped with static electricity erasing means capable of exhibiting the static elimination function necessary to prevent the occurrence of arc discharge generated between the electrically conductive guide member and the paper and prevent the occurrence of problems due to the electrification of the discharged paper. Another object is to provide an image forming apparatus.

[0007]

In order to achieve the above object, an image forming apparatus according to the present invention supplies a sheet of paper to a photoconductor having a toner image formed on the surface thereof so as to contact the photoconductor from the side opposite to the photoconductor. The toner image is transferred to the surface of the paper on the photoreceptor side by applying an electric charge with a polarity different from
In an image forming apparatus configured to guide a sheet on which a toner image is transferred by a sheet guide section and reduce an electric charge of the sheet by an electrostatic eliminator provided in the sheet guide section, the sheet guide section includes a conveyance guide. And a plurality of ribs which are attached to the conveyance guide table and guide the sheet with a predetermined gap formed between the sheet and the conveyance guide table. The static eliminator is provided on the conveyance guide table. It is characterized by being a static electricity elimination sheet that is adhered and fixed.

[0008]

The static eliminator of the image forming apparatus according to the present invention is composed of a static eliminator sheet, and this static eliminator sheet is adhered and fixed to the conveyance guide base of the paper guide section. At this time, the distance between the static eliminator sheet and the sheet can be reliably and accurately maintained by the plurality of ribs without requiring particularly difficult work. Then, the sheet on which the toner image has been transferred is conveyed along the plurality of ribs, and passes over the static elimination sheet in a non-contact state on the way. This will reduce the charge on the paper.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS.
An example will be described. The present embodiment applies the present invention to an optical printer which is one of image forming apparatuses. First, a schematic configuration of the optical printer will be described with reference to the sectional view of FIG. 1 and the functional configuration diagram of FIG. First, there is a frame 1, and a paper feed cassette 3 is installed in this frame 1. Plural sheets of paper (shown by phantom lines in the figure) in the paper feed cassette 3.
5 are housed in a stacked state. These plural sheets of paper 5 are placed on a guide plate 6, and are constantly urged upward by a coil spring 7 stretched between the guide plate 6 and the bottom plate of the paper feed cassette 3. It is in.
Then, the paper feed roller 9 sequentially takes out the uppermost paper 5 and conveys it.

Paper 5 conveyed by paper feed roller 9
Passes through between the pair of rollers 11 and 11 ′ and between the pair of rollers 13 and 13 ′ and passes through the process cartridge 15
It is supplied between the photosensitive drum 17 and the paper guide portion 19. The process cartridge 15 includes a charging unit 21, a developing unit 25, a toner removing unit 27, and the like in addition to the photosensitive drum 17. Further, the paper guide portion 19 is provided with a transfer device 29. Then, first, the toner removing section 27 removes the toner remaining on the photosensitive drum 17, and the charging section 21 applies an electric charge. Next, the exposure unit 23 installed in the apparatus main body irradiates light,
Predetermined image information is formed on the photosensitive drum 17. That is, by irradiating light on the basis of predetermined image information, the charge uniformly applied on the photosensitive drum 17 is partially removed, and thereby predetermined image information is formed on the photosensitive drum 17.

Next, the photosensitive drum 17 is developed by the developing unit 25.
Toner is supplied to the photosensitive drum 17 to form a toner image. Then, the transfer device 29 applies an electric charge having a polarity different from that of the toner from the back side of the sheet 5 to attract the toner to the front side of the sheet 5. As a result, the toner image is transferred from the photosensitive drum 17 to the front side of the sheet 5. The electric charge of the paper 5 to which the toner image has been transferred is reduced by an electrostatic discharge sheet 31 provided in the paper guide portion 19 as an electrostatic discharge unit. Then, the toner image is fixed by the pair of fixing rollers 33 and 33 ′,
Via the pair of rollers 35, 35 ′ and the guide member 37,
The paper will be discharged onto the paper discharge unit 39.

Next, the constructions of the paper guide portion 19 and the static eliminator sheet 31 will be described in detail. Paper guide section 1
9 has a structure as shown in FIG. First, the transport guide base 41 is provided, and the transport guide base 41 is provided.
Is made of, for example, galvanized steel and is grounded to the frame 1. As shown in FIG. 4, the transport guide base 41 is provided with a groove portion 43 on the side where the paper 5 is transported, and has a shape having an inclined portion 45 continuous with the groove portion 43. The discharge wire 30 is stretched in the groove 43. Further, a plurality of slits are formed in the inclined portion 45 at a predetermined interval in a state of being extended in the sheet conveying direction.

As shown in FIG. 5, a plastics component 52 having a plurality of ribs 49 at predetermined intervals is fitted on the conveyance guide base 41 and is conveyed by a plurality of fixing screws (not shown). It is fixed to the guide base 41. The plastics component 51 is formed by integrating the plurality of ribs 49 via the connecting portion 54, and the plurality of ribs 49 are provided in the plurality of slits 47 of the transport guide base 41 in the figure. It is attached and fixed by inserting it from the side. Therefore, as shown in FIG. 3, the ribs 49 project from the plurality of slits 47.

A notch 51 is formed on the upper surface side of the rib 49 in the figure.
Are formed in a tapered shape. The left side portion of the cutout portion 51 in the figure has a plastics component 52 on which the conveyance guide base 41 is attached.
It does not protrude from the upper surface of the transport guide base 41 in the state of being fitted in. Then, the taper gradually protrudes in the sheet conveying direction.
The above-described static electricity elimination sheet 31 is installed above the cutout portion 51 on the left side of the drawing. The static eliminator sheet 31 is adhered and fixed to the upper surface of the end portion of the inclined portion 45 of the conveyance guide base 41 on the groove portion 43 side with an adhesive. Various types of static electricity removing sheets 31 are conceivable, but in the present embodiment, among them, an antistatic tolden seal (model name TPS manufactured by Trex Co., Ltd.
-5) is used. "Truden" is a registered trademark. The above-mentioned anti-static tolden seal is composed of 95% paper and 5% anti-static material, and carbon fiber is used as the anti-static material. Dion (registered trademark) "
Is used. The electrostatic charge eliminating sheet 53 as described above reduces the electric charge of the conveyed paper 5.

The operation will be described based on the above configuration. In FIG. 3, the sheet 5 is conveyed from the left side in the figure. At this time, the transfer device 29 applies a charge having a polarity different from that of the toner to the back side of the sheet 5. As a result, the toner is attracted to the front side of the sheet 5 and the toner image is transferred. afterwards,
The sheet 5 is guided by the upper surfaces of the plurality of ribs 49 and conveyed to the right side in the drawing. At that time, static electricity elimination sheet 3
It will pass over 1 in a contactless manner, which will reduce the charge. Further, since the notch 51 of the rib 49 is formed in a taper shape with an upward slope in the sheet conveying direction, the leading edge of the sheet 5 is not caught in the notch 51 and is smoothly conveyed. The subsequent action is as described above.

By the way, the manner in which the charged electric charges on the surface of the charged paper 5 are removed is as follows. That is, the antistatic material included in the static eliminator sheet 31 is a conductor, and the electrostatic charge of the paper 5 causes the electric charge of the opposite polarity to the electrostatic charge of the paper 5 to be collected on the antistatic material, and the corona between the two. Electric discharge occurs. The charge state of the paper 5 is appropriately eliminated by the neutralizing effect of the electric charge by the corona discharge.

As described in detail above, according to this embodiment, the following effects can be obtained. First, the work of mounting the static eliminator has become extremely easy. That is, it is only necessary to use the static eliminator sheet 31 as the static eliminator and to adhere and fix the static eliminator sheet 31 to a predetermined position of the transport guide portion 41 with an adhesive. Further, since the rib 49 is formed with the cutout portion 51 and there is no projecting member at the position where the static electricity elimination sheet 31 is adhered / fixed, no obstacle is present even when the static electricity elimination sheet 31 is adhered / fixed. Also, the workability of adhesion and fixing work is good. Further, since the static eliminator sheet 31 is not in contact with the sheet 5, the static eliminator sheet 31 is not worn out and the conveyance of the sheet 5 is not disturbed, and the conveyance guide The arc discharge generated near the rear end of the base 41 is prevented, and the transferred toner image is not carelessly disturbed.

Further, in the case of the static eliminator sheet 31, it is extremely easy to keep the gap with the paper 5 constant, and the gap is kept constant as in the case of using the conventional static eliminator brush. It does not require complicated work. That is, the thickness of the static eliminator sheet 31 is constant because it is a standard product, and it is a thin paper-like member having a size that can be substantially ignored. This is because the distance is kept constant. Therefore, it is possible to reliably maintain a constant distance from the paper 5 and obtain a high static elimination effect. By the way, when confirmed by experiment, the distance between the paper 5 and the static eliminator sheet 31 is 0.5.
The optimum value is about to 1.5 mm, which is a numerical value that can be easily realized in the case of the static eliminator sheet 31. or,
This value varies depending on the material used as the static eliminator sheet. Further, the manufacturing cost can be significantly reduced (specifically, about 1/10) as compared with the case of using the static elimination brush. This is because the configuration itself of the static eliminator sheet 31 is extremely simple,
Also, the mounting work is simply performed by adhering and fixing. Further, in the case of the present embodiment, since the transport guide base 41 is formed of a conductive material and is grounded, and the adhesive is also conductive, the static elimination sheet 31 has a static elimination effect. It is effective in increasing the height, but it does not necessarily have to be installed on a metal body.

Next, a second embodiment will be described with reference to FIG. In the case of this embodiment, first, the static eliminator sheet 31 is adhered and fixed on the conveyance guide base 41, and then the plastic component 52 in which the plurality of ribs 49 are integrated via the connecting portion 54 is formed. The transport guide 41 is mounted and fixed so as to be fitted from the lower side. In this case, the notch 55 is formed at a predetermined position on the lower surface side of each rib 49, and the static eliminator sheet 31 is installed at that portion. In the case of this embodiment, it is possible to expect a charge removal effect that is substantially the same as that of the first embodiment, and it is possible to prevent the static charge removal sheet 31 from being separated from the transport guide base 41 by the plurality of ribs 49.

Next, a third embodiment will be described with reference to FIG. In the case of this embodiment, the static eliminator sheet 31 is adhered and fixed to the side wall of the groove portion 43. Further, the static eliminator sheet 31 is provided with a plurality of curved convex portions 31a, and a plurality of curved convex portions 31a are provided. The convex portion 31a is bonded and fixed to the corner of the groove 43. That is, the static eliminator sheet 31 is arranged and opposed to the conveyance path of the paper 5 at a predetermined angle. Also in this case, the same effect as that of each of the above-described embodiments can be obtained.

The present invention is not limited to the above embodiments. First, the size, shape, surface structure, number and the like of the static eliminator sheet 31 are not limited to those illustrated. Further, there are various materials for the static electricity elimination sheet 31 itself other than those shown in the embodiments. For example, although the material is paper in the above-described embodiment, the material is woven fabric, rubber,
It may be a non-woven fabric or the like. Further, in the above-described embodiment, an optical printer has been described as an example of the image forming apparatus, but it is needless to say that it can be similarly applied to a copying machine or the like.

[0022]

As described in detail above, according to the image forming apparatus of the present invention, the static electricity elimination sheet adhered and fixed to the conveyance guide stand of the paper guide unit is used as the static electricity elimination means, and the static electricity elimination sheet is used. The space between the sheet and the paper is configured to be reliably and accurately held by a plurality of ribs. Therefore, first, the structure of the static eliminator is greatly simplified, and the mounting work thereof is extremely simple, whereby the cost can be reduced.
Further, since the static eliminator sheet is not in contact with the paper, there are no problems such as wear of the static eliminator and disturbance of the toner image, which have been a concern in the case of the contact method. In addition, the distance between the static electricity elimination sheet and the paper is
In particular, since it is held reliably and accurately without requiring difficult work, a high static elimination effect can be expected.
It should be noted that the static eliminator sheet according to the present invention is generally processed into a sheet containing an electrically conductive fibrous substance as appropriate, and is self-discharged by approaching the charged body to neutralize the charged charge. It is a general term for those that have an action.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a page printer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a first embodiment of the present invention and is a functional configuration diagram showing a schematic configuration of a page printer.

FIG. 3 is a perspective view showing a configuration of a paper guide unit according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a configuration of a conveyance guide base of a paper guide unit according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a plastics component including a rib of a paper guide portion according to the first embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a paper guide portion according to the second embodiment of the present invention.

FIG. 7 is a diagram showing a second embodiment of the present invention and is a perspective view showing a configuration of a paper guide portion.

FIG. 8 is a functional configuration diagram showing a schematic configuration of a page printer in a conventional example.

FIG. 9 is a perspective view showing a configuration of a paper guide portion in a conventional example.

[Explanation of symbols]

 5 Paper 17 Photosensitive Drum (Photoreceptor) 19 Paper Guide Section 30 Discharge Wire 31 Static Elimination Sheet (Static Elimination Means) 41 Transport Guide Stand 49 Rib

Claims (1)

[Claims] 1. A sheet of paper is supplied to and brought into contact with a photoconductor having a toner image formed on the surface thereof, and a charge having a polarity different from that of the toner is applied from a side of the paper opposite to the photoconductor, thereby forming a toner on the surface of the paper on the photoconductor side. In an image forming apparatus configured to transfer an image, guide a sheet on which a toner image has been transferred by a sheet guide section, and reduce an electric charge of the sheet by an electrostatic eliminator provided in the sheet guide section,
The paper guide unit includes a conveyance guide base and a plurality of ribs attached to the conveyance guide base for guiding the paper with a predetermined distance between the paper and the conveyance guide base. The static eliminator is attached to the above-mentioned transport guide base.
An image forming apparatus, which is a fixed static eliminator sheet.