JP3407584B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus for transferring a toner image carried on a toner image carrier to printing paper. 2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with high resolution, such as laser printers, have become widespread. Among such toner-type image forming apparatuses, as proposed in Japanese Patent Application No. 7-328600, the toner image carrier is moved while moving the toner image carrier in a direction orthogonal to the printing paper conveyance direction. An orthogonal transfer type image forming apparatus that rubs on a printing paper and transfers a toner image in small steps one by one is very suitable for promoting miniaturization of a product due to its configuration. Hereinafter, a conventional image forming apparatus using such an orthogonal transfer system will be described. FIG. 4 is a configuration diagram showing a conventional image forming apparatus of the orthogonal transfer type, and FIG. 5 is a perspective view of a main part showing a main part of the conventional image forming apparatus of the orthogonal transfer type. 4 and 5, reference numeral 1 denotes a toner image carrier formed of a photosensitive belt, 2 denotes a charger, 3 denotes a developing device, 3a denotes a toner, 3b denotes a developing roller, 3c denotes a toner image, 4 denotes a cleaning device, and 5 denotes a cleaning device. Static eliminator, 6 is an exposure unit, 7 is printing paper, 8
Denotes a transfer opposing roller, 9 denotes a support roller, 10 denotes a displacement roller, 11 denotes a transfer plate, 12 denotes a heat source, 13 denotes a reflection plate, 14 denotes a reflection conveyance plate, 15 denotes a fixing device, and 16 denotes a contact roller. The arrangement, operation, and the like of the image forming apparatus configured as described above will be described. As shown in FIG. 4, the toner image carrier 1 whose surface is coated with a layer of an organic photoconductive material is transported by at least three rollers of a support roller 9, a displacement roller 10, and a transfer opposing roller 8 in the transport direction of the printing paper 7. It is stretched in a direction orthogonal to X (see FIG. 5), and rotates in the direction of arrow A during image formation, whereby a toner image is formed on the surface of the toner image carrier 1.
Around the toner image carrier 1, a cleaning device 4, a static eliminator 5, a charging device 2, and a developing device 3 are sequentially arranged in the rotation direction of the toner image carrier 1 (the direction of arrow A). An exposing device 6 for irradiating a laser beam 6a is disposed on the upper part of the device 1. Here, a case where a laser is used as a typical example of the exposure unit 6 will be described.
May use not only lasers but also LEDs and LCDs. When the toner image carrier 1 rotates in the direction orthogonal to the transport direction X of the printing paper 7 as shown by the arrow A, the portion passing through the charger 2 is uniformly charged to about -600 V, and becomes an image signal. Then, the potential of the portion irradiated with the laser beam 6a by the exposure device 6 rises to about -100 V, thereby forming an electrostatic latent image. When the toner 3a is pressed against the portion where the electrostatic latent image is formed by the developing roller 3b, visible toner images 3c appear on the toner image carrier 1 one after another. Here, the contact roller 16 is disposed so as to face the developing roller 3b with the toner image carrier 1 interposed therebetween. The contact roller 16 is formed of a sponge roller or the like, and the developing roller 3b is connected via the toner image carrier 1 so that the developing roller 3b contacts the toner image carrier 1 with an appropriate pressure.
Is in contact with As a developing method in the developing device 3, a non-magnetic one-component developing method has been widely used in recent years because of its simple structure and low cost. The non-magnetic one-component developing method is a method in which a thin layer is formed on a conductive rubber roller with a developing blade, and the rubber roller is brought into contact with the toner image carrier 1 to perform development. At this time, the developing roller 3b
As a material, a Si rubber roller made of Si rubber is often used. A feature of such an orthogonal transfer type image forming apparatus is that, at the time of transfer, the rotation of the toner image carrier 1 and the conveyance of the printing paper 7 are temporarily stopped, and the toner image carrier 1 The movement of the roller 8 in the transfer direction Y (see FIG. 5) causes the roller 8 to rub against the printing paper 7 and be displaced. At this time, the displacement roller 10 is displaced following the movement of the transfer opposing roller 8 in order to eliminate the slack of the toner image carrier 1. Every time the transfer in one process is completed, the transfer opposing roller 8 moves over the printing paper 7 and out of the area of the printing paper 7, so that the toner image carrier 1
Keep away from Then, the conveyance of the printing paper 7 is started, and the conveyance distance of the printing paper 7 is equal to the effective transfer width of the toner image carrier 1. The printing paper 7 is sent intermittently by the amount corresponding to the effective transfer width to the fixing device 15 side where the toner is fixed without contacting the printing paper 7. As shown in FIG. 5, the fixing device 15 that fixes the toner in a non-contact manner irradiates a heat source 12 for irradiating a heat ray to melt the toner particles of the image transferred onto the printing paper 7, and irradiates the heat source 12. A reflection plate 13 for reflecting heat rays to the printing paper 7 is provided. A reflection conveyance plate 14 is disposed below the fixing device 15 to improve thermal efficiency and fix the toner without contacting the toner. However, in the conventional image forming apparatus, when the non-magnetic one-component developing method is used, the developing roller 3b and the toner image carrier 1 are always kept in contact. Since the developing roller 3b uses Si rubber or the like, the toner image carrier 1 is contaminated by permanent deformation of the developing roller 3b or extraction of components from the Si rubber or the like, and the toner image such as uneven charging and uneven sensitivity is formed. There is a problem that the characteristics of the carrier 1 may be deteriorated and the print quality may be degraded. In this image forming apparatus, it is required that the printing quality can be stably maintained by reducing the contamination of the toner image carrier and the deterioration of characteristics due to the deformation of the developing roller and the extraction of the rubber component of the developing roller. An object of the present invention is to provide an image forming apparatus capable of stably maintaining print quality by reducing contamination and characteristic deterioration of a toner image carrier due to deformation of a developing roller and extraction of a rubber component of the developing roller. Aim. [0012] In order to solve this problem, an image forming apparatus according to the present invention is arranged such that the transfer opposing roller is a belt.
The toner image is carried on the toner image carrier by being in contact with the developing roller of the developing device via the toner image carrier comprising the toner image carrier, and the toner image carried on the toner image carrier is transferred to print paper by the transfer opposing roller. An image forming apparatus for fixing a toner image transferred to a printing paper, wherein a developing device is arranged at a position where a developing roller can be separated from and separated from a transfer opposing roller via a toner image carrier; The roller contacts the developing roller via the toner image carrier during development.
The toner image carrier during transfer.
Rubbing on the printing paper as the transfer opposing roller moves
Is provided. Thus, an image forming apparatus capable of stably maintaining print quality by reducing contamination of the toner image carrier and deterioration of characteristics due to deformation of the developing roller and extraction of the rubber component of the developing roller can be obtained. The invention according to the first aspect of the present invention is directed to a toner image carrier in which a transfer opposing roller contacts a developing roller of a developing device via a toner image carrier composed of a belt. An image forming apparatus for carrying a toner image on a toner image carrier, transferring the toner image carried on the toner image carrier to printing paper by a transfer opposing roller, and fixing the toner image transferred to the printing paper, wherein the developing device is a developing device. The roller is disposed at a position where the roller can be separated from and attached to the transfer opposing roller via the toner image carrier , and the transfer opposing roller holds the toner image during development.
Placed at a position where it contacts the developing roller
In this case, the toner image carrier is
It is to be displaced so as to rub against the printing paper , and the transfer facing roller contacts the developing roller,
It has the effect of coming and going. Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a configuration diagram showing an image forming apparatus according to Embodiment 1 of the present invention. 1, a toner image carrier 1, a charger 2, a developing device 3, a toner 3a, a developing roller 3b, a cleaning device 4, a static eliminator 5, an exposure device 6,
The laser beam 6a, the printing paper 7, the transfer opposing roller 8, the support roller 9, the displacement roller 10, and the transfer plate 11 are the same as those in FIG. The arrangement, operation, and the like of the image forming apparatus configured as described above will be described. As shown in FIG. 1, the toner image carrier 1 whose surface is coated with a layer of an organic photoconductive material is transported by at least three rollers of a support roller 9, a displacement roller 10, and a transfer opposing roller 8 in a conveying direction of the printing paper 7. It is stretched in a direction orthogonal to X (see FIG. 5), and rotates in the direction of arrow B during image formation, whereby a toner image is formed on the surface of the toner image carrier 1.
Around the toner image carrier 1, a cleaning device 4, a static eliminator 5, a charger 2, and a developing device 3 are sequentially arranged in the rotation direction of the toner image carrier 1 (in the direction of arrow B). That is, the rotation direction of the toner image carrier 1 is different between the image forming apparatus of FIG. 1 and the image forming apparatus of FIG. 4, and therefore, the arrangement of the cleaning device 4, the neutralizing device 5, the charging device 2, and the developing device 3 is different. In particular, the arrangement of the developing device 3 is largely different from that of FIG. Toner image carrier 1
An exposing device 6 for irradiating a laser beam 6a is disposed above the. Here, a case where a laser is used as a typical example of the exposure device 6 will be described. However, the exposure device 6 may use not only a laser but also an LED or an LCD. When the toner image carrier 1 rotates in the direction perpendicular to the transport direction X of the printing paper 7 as shown by the arrow B, the portion passing through the charger 2 is uniformly charged to about -600 V, and becomes an image signal. Then, the potential of the portion irradiated with the laser beam 6a by the exposure device 6 rises to about -100 V, thereby forming an electrostatic latent image. When the toner 3a is pressed against the portion where the electrostatic latent image is formed by the developing roller 3b, visible toner images appear one after another on the toner image carrier 1. A feature of such an orthogonal transfer type image forming apparatus is that, at the time of transfer, the rotation of the toner image carrier 1 and the conveyance of the printing paper 7 are temporarily stopped, and the toner image carrier 1 The movement of the roller 8 in the transfer direction Y (see FIG. 5) causes the roller 8 to rub against the printing paper 7 and be displaced. At this time, the displacement roller 10 is displaced following the movement of the transfer opposing roller 8 in order to eliminate the slack of the toner image carrier 1. The transfer opposing roller 8 is disposed at a position in contact with the developing roller 3b at the time of development, and the transfer plate 11 is at the time of transfer.
Move up. In addition, at the time of non-printing, it is arranged at a position not contacting the developing roller 3b (non-contact position, separation position).
Specifically, the non-printing position is preferably on the right side of the developing roller 3b from the viewpoint of miniaturization of the apparatus. By making the configuration such that the developing roller 3b does not contact the toner image carrier 1 during non-printing, the toner image carrier 1 is stained due to permanent deformation of the developing roller 3b and the rubber component of the developing roller 3b is extracted. Since the unevenness can be reduced, the characteristic deterioration of the toner image carrier 1 can be reduced, and the printing quality can be stably maintained. Each time the transfer in one process is completed, the transfer image opposing roller 8 moves over the printing paper 7 and out of the area of the printing paper 7 so that the toner image carrier 1
Keep away from Then, the conveyance of the printing paper 7 is started, and the conveyance distance of the printing paper 7 is equal to the effective transfer width of the toner image carrier 1. The printing paper 7 is intermittently sent to the fixing device 15 (see FIG. 5) for fixing the toner in a non-contact manner with the printing paper 7 by the effective transfer width. In the present embodiment, an image forming apparatus of the orthogonal transfer type has been described. However, the present invention is not limited to this, and can be similarly applied to an image forming apparatus of a parallel transfer type. That is, the printing paper 7 on the transfer plate 11 in FIG. 1 can be conveyed from right to left, for example, by the length of one printing paper, and the printing paper 7 can be stopped to perform the transfer. As described above, according to the present embodiment, the developing device 3 is arranged such that the developing roller 3b can be brought into contact with the transfer opposing roller 8, and the transfer opposing roller 8 is set at the time of development (at the time of printing). Is arranged at a position in contact with the developing roller 3b, and is arranged at a position away from the developing roller 3b when printing is not performed.
Since contamination of the toner image carrier 1 and uneven charging and uneven sensitivity due to the extraction of the rubber component b can be reduced, the characteristic deterioration of the toner image carrier 1 can be reduced and the print quality can be stably maintained. can do. (Embodiment 2) FIGS. 2 and 3 are configuration diagrams showing an image forming apparatus according to Embodiment 2 of the present invention. 2 and 3, the toner image carrier 1,
Charging device 2, developing device (first developing device) 3, toner 3a, developing roller 3b, cleaning device 4, static eliminator 5, exposure device 6, laser beam 6a, printing paper 7, transfer facing roller 8, support roller 9 , The displacement roller 10 and the transfer plate 11 are the same as those in FIG. 17
Is a second developing device having the same configuration as the first developing device 3, 17a
Denotes a toner of the developing device 17, and 17b denotes a developing roller of the developing device 17. The arrangement, operation, and the like of the image forming apparatus configured as described above will be described. As shown in FIGS. 2 and 3, the toner image carrier 1 whose surface is coated with a layer of an organic photoconductive material comprises a support roller 9 and a displacement roller 1.
0, which is stretched in a direction orthogonal to the transport direction X (see FIG. 5) of the printing paper 7 by at least three rollers of the transfer opposing roller 8, and is rotated in the direction of arrow B at the time of image formation so that the toner image A toner image is formed on the surface of the carrier 1. Around the toner image carrier 1, the toner image carrier 1
Cleaning device 4, static eliminator 5, charger 2, second developing device 17, first developing device 3
Are arranged in order. Thus, unlike the image forming apparatus of FIG. 1, the image forming apparatuses of FIGS. 2 and 3 have the two developing units 17 and 3, and the developing rollers 17b and 3b are connected via the toner image carrier 1. It is arranged at a position where it can come into contact with the transfer opposing roller 8. A laser beam 6 is provided on the toner image carrier 1.
Exposure device 6 for irradiating a is provided. Here, a case where a laser is used as a typical example of the exposure unit 6 will be described.
D or LCD may be used. When the toner image carrier 1 rotates in the direction orthogonal to the transport direction X of the printing paper 7 as shown by the arrow B, the portion that has passed through the charger 2 is uniformly charged to about -600 V, and is converted into an image signal. Then, the potential of the portion irradiated with the laser beam 6a by the exposure device 6 rises to about -100 V, thereby forming an electrostatic latent image. When the toner 17a or the toner 3a is pressed against the portion where the electrostatic latent image is formed by the developing roller 17b or the developing roller 3b, visible toner images appear on the toner image carrier 1 one after another. Switching between the developing units 17 and 3 is performed when the transfer opposing roller 8 is stopped. The characteristic of such an orthogonal transfer type image forming apparatus is that, at the time of transfer, the rotation of the toner image carrier 1 and the conveyance of the printing paper 7 temporarily stop, and the toner image carrier 1 The movement of the roller 8 in the transfer direction Y (see FIG. 5) causes the roller 8 to rub against the printing paper 7 and be displaced. At this time, the displacement roller 10 is displaced following the movement of the transfer opposing roller 8 in order to eliminate the slack of the toner image carrier 1. At the time of the first development (for example, at the time of yellow development and cyan development), the transfer opposing roller 8 is at a position in contact with the developing roller 3b of the first developing device 3, as shown in FIG. Arranged to form a toner image on the toner image carrier 1,
At the time of transfer, it moves on the transfer plate 11. Further, at the time of the second development (for example, at the time of magenta development, at the time of black development), as shown in FIG.
It is arranged at the position where it comes into contact with. At the time of non-printing, the transfer opposing roller 8 is arranged at a position where the toner image carrier 1 and the developing rollers 3b and 17b do not abut. The position at the time of non-printing is specifically, from the viewpoint of miniaturization of the apparatus, the developing roller 3b
The right side of is preferred. Developing rollers 3b, 17b during non-printing
And the toner image carrier 1 are not in contact with each other, so that the permanent deformation of the developing rollers 3b and 17b and the developing roller 3
Since contamination of the toner image carrier 1 and uneven charging and uneven sensitivity due to the extraction of the rubber components b and 17b can be reduced, the characteristic deterioration of the toner image carrier 1 can be reduced and the print quality can be stably maintained. Can be maintained. Each time the transfer in one process is completed, the transfer image opposing roller 8 moves over the print paper 7 and moves out of the area of the print paper 7 so that the toner image carrier 1
Keep away from Then, the conveyance of the printing paper 7 is started, and the conveyance distance of the printing paper 7 is equal to the effective transfer width of the toner image carrier 1. The printing paper 7 is intermittently sent to the fixing device 15 (see FIG. 5) for fixing the toner in a non-contact manner with the printing paper 7 by the effective transfer width. In the conventional apparatus shown in FIG. 4, the developing roller 3b requires the contact roller 16, and when two or more developing units are arranged, the developing roller of each color is changed to a toner image in order to change the developing color. An electromagnetic clutch that separates from and separates from the carrier 1 is required, causing an increase in cost. In the present embodiment, the developing device capable of developing can be switched depending on the stop position of the transfer opposing roller 8. That is, the developing devices 3 and 17 are used such that the developing device 3 is used when the transfer opposing roller 8 contacts the developing roller 3 b of the developing device 3, and the developing device 17 is used when the transfer opposing roller 8 contacts the developing roller 17 b of the developing device 17. Is switched. In this embodiment, the image forming apparatus of the orthogonal transfer type has been described. However, the present invention is not limited to this, and can be similarly applied to an image forming apparatus of the parallel transfer type. That is, the transfer plate 11 shown in FIGS.
For example, the upper printing paper 7 may be conveyed from right to left by the length of one printing paper, and the printing paper 7 may be stopped to perform the transfer. As described above, according to the present embodiment, the first and second developing units 3 and 17 are arranged so that the developing rollers 3b and 17b can come into contact with the transfer opposing roller 8, and The roller 8 is disposed at a position in contact with the developing roller 3b during the first development, and the developing roller 17b during the second development.
Is arranged at a position where the developing roller 3b, 17b is permanently deformed, and the developing device removes contamination, uneven charging, and uneven sensitivity of the toner image carrier 1 due to extraction of the rubber component of the developing rollers 3b, 17b. Since it is possible to further reduce the deterioration as compared with the case where the number of prints is small, it is possible to more reliably reduce the deterioration of the characteristics of the toner image carrier 1 and to stably maintain the print quality. Further, the cost can be reduced by eliminating the need for an electromagnetic clutch that separates and separates the developing rollers of each color from the toner image carrier. As described above, according to the image forming apparatus of the present invention, the transfer opposing roller as the contact roller can contact or separate from the developing roller. It is possible to reduce contamination, uneven charging and uneven sensitivity of the toner image carrier due to permanent deformation and extraction of the rubber component of the developing roller. Has an advantageous effect of being able to be maintained. [0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a configuration diagram showing an image forming device according to a second embodiment of the present invention. FIG. 4 is a configuration diagram illustrating an image forming apparatus according to a second embodiment of the invention. FIG. 4 is a configuration diagram illustrating a conventional image forming apparatus using an orthogonal transfer system. FIG. DESCRIPTION OF REFERENCE NUMERALS 1 Toner image carrier 2 Charger 3, 17 Developing device 3a, 17a Toner 3b, 17b Developing roller 4 Cleaning device 5 Static eliminator 6 Exposure device 7 Printing paper 8 Transfer facing roller 9 Supporting roller 10 Displacement roller 11 Transfer plate 12 Heat source 13 Reflector 14 Reflective transport plate 15 Fixer

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masashi Ogawa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. In-house (72) Inventor Yusuke Shiihara 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Field (Int.Cl. ⁷ , DB name) G03G 15/08 507 G03G 15/01 113 G03G 15/01 114

Claims (1)

(57) Claims 1. A transfer opposing roller is brought into contact with a developing roller of a developing device via a toner image carrier formed of a belt, thereby carrying a toner image on the toner image carrier. transferred by the transfer opposing roller toner image carried on the toner image bearing member to the printing paper, an image forming apparatus for fixing a toner image transferred to the print sheet, wherein the developing device is the developing roller wherein The toner image is carried on the transfer opposing roller.
The transfer opposing roller is disposed at a position such that the transfer opposing roller can be separated from and connected to the toner image carrier during development.
And placed at a position in contact with the developing roller,
When the toner image carrier is moved by the transfer opposing roller,
The image forming apparatus is also displaced so as to rub against printing paper .