JPH0543168U - Image forming device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an image forming apparatus that suppresses unwanted adhesion of toner to such a transfer material and forms a beautiful image. A surface of the guide means that is in sliding contact with the non-transfer surface of the transfer material is made of a conductive member, and the photosensitive member is moved between the image development point of the developing device and the transfer surface of the transfer material. The wind direction changing means for changing the direction of the wind generated in the moving direction to a direction away from the moving direction is arranged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image forming apparatus that visualizes an electrostatic latent image formed on a photoconductor with toner, such as an electrophotographic copying machine, an electrostatic recording device, a plain paper facsimile, a laser printer, an LED printer, etc. Used for.

[0002]

[Prior Art]

 As is well known, the above-mentioned image forming apparatus generally comprises a drum-shaped or endless belt-shaped photosensitive member, around which charging, exposing, developing, transferring, cleaning and neutralizing means are sequentially provided. It is provided.

That is, the photosensitive member is uniformly charged by the charging unit, then moved to the next exposure unit, and an electrostatic latent image is formed by selective exposure according to the image to be formed. Then, the electrostatic latent image on the photoconductor is visualized by the toner by the next developing means, and the toner is transferred to the transfer material conveyed by the transfer means. The transferred toner is fixed by the fixing means and then discharged from the main body of the apparatus, and the photoconductor further moves to remove the residual toner and remove the charge by the cleaning means and the charge removing means.

[0004]

[Problems to be solved by the device]

 In such an image forming apparatus, when the image forming process with one cycle of charging and discharging is repeatedly executed, the transfer is carried in order to transfer the toner on the downstream side of the developing unit in the moving direction of the photosensitive member. Undesired toner adheres to the material, causing a trouble that stains the transfer material.

Therefore, it is an object of the present invention to provide an image forming apparatus that suppresses unwanted adhesion of toner to such a transfer material and forms a beautiful image.

[0006]

Means for Solving the Problem In order to solve the above problems, the present invention visualizes a movable photosensitive member and an electrostatic latent image formed on the photosensitive member with toner. A developing device, a transfer device that transfers the image visualized by the developing device to a transfer material, and a guide unit that guides the transfer material between the transfer device and the photoconductor. A surface of the guide means that is in sliding contact with the non-transfer surface of the transfer material is formed of a conductive member, and the surface of the guide member is moved by the movement of the photoconductor between the image development point of the developing device and the transfer surface of the transfer material. It is characterized in that wind direction changing means for changing the direction of the wind generated in the moving direction to a direction away from the moving direction is arranged.

[0007]

[Action]

 As described above, by forming the surface of the guide means in sliding contact with the non-transfer surface of the transfer material with a conductive member, the transfer material is prevented from being triboelectrically charged during conveyance of the guide means, and at the same time, the developing device is exposed. By arranging between the image point and the transfer surface of the transfer material, wind direction changing means for changing the direction of the wind generated by the movement of the photoconductor in a direction away from the movement direction. Therefore, it is possible to prevent the toner scattered from the developing device by being scattered by the wind to be transferred to the transfer material.

[0008]

【Example】

 An embodiment of the image forming apparatus of the present invention will be described with reference to the schematic side view of the essential portion shown in FIG.

In FIG. 1, reference numeral 1 denotes an organic photosensitive member such as polyvinylcarbazole, a photosensitive drum made of a photoconductive semiconductor such as amorphous Se or amorphous Si, and 2 supplies toner to the peripheral surface of the photosensitive drum 1. A developing device in which a magnet roller 3 is disposed in close proximity to the developing device 2. The developing device 2 visualizes an electrostatic latent image formed on the peripheral surface of the photosensitive drum 1 with toner by a charging and exposing process (not shown). Image. Reference numeral 4 denotes a transfer material 5 which is provided substantially opposite to the bottom surface of the photoconductor drum 1 so as to charge the transfer material 5 such as plain paper with a polarity opposite to the charge polarity of the toner attached to the photoconductor drum 1. The transfer device 6 transfers the toner to the transfer material 5, and the separator 6 electrostatically separates the transfer material 5 to which the toner is transferred from the transfer device 4 from the photosensitive drum 1.

Reference numeral 7 denotes a guide unit that contacts the photoconductor drum between the transfer unit 4 and the photoconductor drum 1 and supplies and guides the transfer material 5 from the tangential direction. The rollers 71, 72, the upper regulation plate 73, the lower regulation plate 74 that regulates the guide direction by using the facing gap as a conveyance path, and the conveyance path surface of the lower regulation plate 74, that is, the non-transfer surface of the transfer material 5 slides. The conductive film 75 is provided on the contact surface and is connected to the chassis of the main body of the apparatus.

Reference numeral 8 denotes a device which is provided in the vicinity of a downstream side of the developing device 2 in the rotation direction of the photosensitive drum 1 and separates the direction of wind generated along the peripheral surface of the photosensitive drum 1 from the peripheral surface as the photosensitive drum 1 rotates. A first wind direction changing plate made of a urethane film that changes its direction supports the lower edge of the developing device 2 on the drum side, and also acts as a guide when the developing device 2 is extracted or inserted in the axial direction of the photoconductor drum 1. It is attached to the support 9. Reference numeral 10 denotes a second wind direction changing plate, which is screwed onto the upper surface of the upper regulating plate 73 of the guide means 7 shown in FIG. 2 as shown in FIG.

Thus, the electrostatic latent image formed on the peripheral surface of the photosensitive drum 1 is developed with the charged toner supplied by the magnet roller 3 of the developing device 2 as the rotational movement is performed, and further transferred to the transfer device 4. Move towards. As the photosensitive drum 1 moves, wind is generated on the peripheral surface of the drum 1 along the peripheral surface thereof. However, on the downstream side in the rotation direction of the opening 21 of the developing device 1, the opening is formed. Since the first wind direction changing plate 8 that acts as a resistance plate against the wind is provided so as to block 21 together with the photoconductor drum 1, the wind is prevented from flowing along the peripheral surface. 1 is deflected in the direction indicated by the arrow a. At this time, the toner carried by the wind, especially the uncharged toner that does not electrostatically adhere to the photosensitive drum 1, is prevented from being scattered to the transfer unit 4 side by the deflected wind. To be done. The scattered toner is mainly flown in the gap between the first wind direction changing plate 8 and the support 9 that supports the changing plate 8 in a direction away from the wind direction of the moving direction of the photosensitive drum 1.

Further, as the rotation of the photosensitive drum 1 progresses, the developed portion passes near the second wind direction changing plate 10. Also at this time, the wind flowing along the peripheral surface of the photoconductor drum 1 is deflected in the direction indicated by the arrow b in FIG. 1, and the toner transfer unit 4 side that could not be suppressed by the first wind direction changing plate 8 To prevent further dispersion. That is, the toner scattered toward the transfer device 4 side as the photosensitive drum 1 rotates changes the scattering direction due to the presence of the first and second wind direction changing plates 8 and 10, and thus the transfer material 5 is polluted. Absent.

On the other hand, the transfer material 5 that has been conveyed while sliding in contact with the conductive film 75 in the facing gap between the upper and lower regulating plates 73 and 74 of the guide means 7 is transferred to the transfer device 4 without being frictionally charged during the conveyance. The toner supplied and held here on the surface of the photosensitive drum 1 is transferred to the transfer material 5 side. At this time, undesired scattered toner due to frictional charging of the transfer material 5 itself is not adsorbed. Therefore, only a predetermined toner image is transferred onto the transfer material 5, and it is possible to form a beautiful image on the transfer material through predetermined processes thereafter.

In such a structure, a chart in which the ratio of characters, figures, etc. to the paper surface is 12% is used as the original, the charge amount of the toner and the carrier is 8 to 12 microcoulombs / g, and the mixing ratio of the carrier and the toner. The toner density is 5%, the photoconductor drum 1 is -630 V, and the magnet roller 3 of the developing device 2 is -170 V, and a continuous copying test is performed using plain paper as the transfer material 5. However, even after 2000 sheets were copied, the smear on the plain paper due to the scattered toner was not recognized, but the adhesion of the scattered toner could not be completely prevented.

At the same time, the first comparative test was conducted under the same conditions except that the first and second wind direction changing plates 8 and 10 were removed and an insulating film made of a polyester film was used in place of the conductive film 75 of the guide means 7. As a result, the scattered toner and the adherence of the carrier were visually observed on the surface of the copy paper after several hundreds of sheets, and then remarkable stains were observed.

Under the same conditions, the first and second wind direction changing plates 8 and 10 are returned to the attached state, and an insulating film made of a polyester film is used instead of the conductive film 75 of the guide means 7. When the second comparison test was carried out, the copy paper surface was less contaminated than the first comparison experiment.

[0018]

[Effect of the device]

 In the present invention, as is apparent from the above description, the surface of the guide means that is in sliding contact with the non-transfer surface of the transfer material is made of a conductive member, so that the transfer material is prevented from being charged with friction during the conveyance of the guide means. Between the image development point of the developing device and the transfer surface of the transfer material, wind direction changing means for changing the direction of the wind generated in the moving direction of the photoconductor in a direction away from the moving direction is arranged. By doing so, it is possible to prevent the toner scattered from the developing device by riding on the wind to be transferred to the transfer material, so that the transfer material can be protected from such toner scattering, and a beautiful image can be obtained for a long time. Can be formed.

[Brief description of drawings]

FIG. 1 is a schematic side view of a main part in an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a perspective view of an essential part of an embodiment of the image forming apparatus of the present invention.

FIG. 3 is a perspective view of a main part of an embodiment of the image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Developing device 4 Transfer device 5 Transfer material 7 Guide means 73 Upper regulating plate 74 Lower regulating plate 75 Conductive film 8 First wind direction changing plate 10 Second wind direction changing plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Masami Makino 2-18, Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A photosensitive member movably provided, a developing device for developing an electrostatic latent image formed on the photosensitive member with toner, and an image visualized by the developing device as a transfer material. A transfer device for transferring, a guide means for guiding the transfer material between the transfer device and the photoconductor, and a surface of the guide means that is in sliding contact with the non-transfer surface of the transfer material is made of a conductive member, Wind direction changing means for changing the direction of the wind generated in the moving direction of the photosensitive member in the moving direction away from the moving direction is disposed between the image development point of the developing device and the transfer surface of the transfer material. An image forming apparatus characterized by the above.