Mita Industrial Co., Ltd.

Mita Industrial

Ryuji Wataki

Shigeo Fujita

Yuzuru Nanjo

Noritaka Okazaki

Michio Uchida

Yuki Ito

Eiji Nimura

Masahiko Maeda

Yukihiro Aikawa

Toru Nakazawa

Shinji Koga

Yasuharu Utsunomiya

Hiroyuki Nonaka

Yuki Itoh

A device for cleaning a transfer belt of an image-forming machine in which the transfer belt is wound around a drive roller and a driven roller that are disposed at a predetermined distance, in parallel with each other and is positioned opposite a photosensitive material drum in a transfer zone. A fur brush which has an electrically conducting property is rotated in contact with the surface of the transfer belt. A bias voltage is applied to the fur brush, the bias voltage having a polarity the same as the polarity for electrically charging the toner of a toner image formed on the photosensitive material drum. An opposed electrode is disposed opposite the fur brush and in contact with the back surface of the transfer belt.

Device for cleaning a transfer belt of an image-forming machine

This invention relates to an image forming apparatus with a transfer unit for transferring toner electrically to an electrostatic latent image formed on a photoreceptor onto a copy sheet. The image forming apparatus has a transfer electrode charge supply means for supplying electric charges to a transfer electrode provided in the transfer unit to electrically attract the toner onto the copy sheet and control means for controlling the quantity of electric charges to be supplied to the photoreceptor via the transfer electrode from the transfer electrode charge supply means based on a photoreceptor inflow current flowing to the photoreceptor through the charge send/receive means and on a photoreceptor outflow current flowing out from the photoreceptor through a ground wire connecting the photoreceptor and the ground. The charge send/receive means, other than the transfer unit, sends and receives electric charges to and from the photoreceptor. With this arrangement, variation of photoreceptor inflow current due to image density variation of an original document can be controlled to perform a stable image transfer.

Image forming apparatus with transfer current controller and method of

An image-transfer and sheet-separating apparatus transfers an image toner-developed from a positive latent image and retained on a photoconductor drum onto a copy sheet, and subsequently separates the sheet from the photoconductor drum. A bias voltage including a sheet peel-separating AC voltage superimposed on an image-transferring DC bias voltage is applied to a transfer roller which presses on the photoconductor drum. A post image-transfer charge-stripping element removes charge from the copy sheet and is disposed in a portion of the sheet-transport stream forward of a nipping position at which the transfer roller presses against the photoconductor drum. Thus, charge remaining on the copy sheet is discharged, ensuring high efficiency in image transfer and accordingly reducing the incidence of failure in the separation of the copy sheet from the photoconductor drum. The bias voltage is within the range of 500 V and 2000 V and specifically, the AC and DC biases are within the range of 1000 V and 1500 V. In addition, the transfer roller is moved toward or away from the photoconductor depending on the thickness of the copy sheet.

Image-transfer and sheet-separation apparatus

A multi-directional driving mechanism includes a moving plate supported rotatably on a supporting shaft and having an input portion and a plurality of output portions, a solenoid coupled to the input portion of the moving plate for causing the moving plate to pivot through a predetermined angle, and a plurality of coupling members each having one end coupled to the plurality of output portions provided on the moving plate. A transfer device for an image forming machine has contacting/separating mechanisms for moving a transfer belt unit, a moving mechanism for moving a cleaning blade, and the multi-directional driving mechanism, the other end each of the plurality of coupling members of the multi-directional driving mechanism being coupled to the contacting/separating mechanisms or the moving mechanism.

Multi-directional driving mechanism and transfer device for an image

A transfer device for an image forming machine has a belt unit including a driving roller, a driven roller disposed at a distance from the driving roller, a transfer belt looped between the driving roller and the driven roller, and a transfer roller disposed opposite an image bearing member with the transfer belt interposed therebetween; a contacting/separating device for moving the belt unit between a transfer position and a non-transfer position; and a voltage source for applying a predetermined voltage onto the transfer roller. The transfer roller is disposed apart from the transfer belt, and when the belt unit is brought to the transfer position by the contacting/separating device, the transfer roller presses the transfer belt against the image bearing member. Another embodiment includes a cleaning blade disposed apart from the transfer belt, and which in the transfer position contacts the transfer belt.

Transfer device for an image forming machine

An image forming machine equipped with a transfer belt unit includes a safety detecting means for detecting the completion of setting of an opening/closing member constituting the image forming machine, and a controlling means for controlling the operation of a driving means for a driving roller on the basis of a signal from the safety detecting means. When the safety detecting means signals the completion of the setting after signaling the incompletion of the setting, the controlling means controls the driving means so as to perform a reverse driving, thereby driving the driving roller reversely by a predetermined amount.

Image forming machine

A transfer device of an image forming machine has a belt unit comprising a pair of supporting plates disposed with a predetermined spacing, a driving roller journaled rotatably at one end portion of the pair of supporting plates, a driven roller journaled rotatably at the other end portion of the pair of supporting plates with a predetermined spacing from the driving roller, a transfer roller disposed between the driving roller and the driven roller, journaled rotatably on the pair of supporting plates, and given a predetermined voltage, and a transfer belt looped among the driving roller, the driven roller and the transfer roller, and disposed opposite an image bearing member. The transfer belt of the belt unit is formed so as to have a width larger than the spacing between the pair of supporting plates, and is disposed such that its side end portions surround at least part of the pair of supporting plates.

Transfer device of image forming machine

A transfer device for an image forming machine has a driving roller, a driven roller disposed at a distance from the driving roller, a transfer belt extending between the driving roller and the driven roller, a transfer roller disposed opposite an image bearing member, with the transfer belt interposed therebetween and pressing the transfer belt against the image bearing member, and a voltage source for applying a predetermined voltage onto the transfer roller. The transfer roller consists of a rotating shaft and a roller portion mounted on the rotating shaft, and the hardness of the roller portion is set to result in a compression of 0.45 to 2.00 mm at a linear pressure of 3 g/cm. The volume resistivity of the roller portion of the transfer roller is set at 10.sup.2 to 10.sup.9 ohm-centimeters.

Transfer device for image forming machine

A cleaning device for cleaning an endless transfer belt which is made of elastic material and stretched between a first roller and a second roller, one of the two rollers being adapted for driving the belt, the transfer belt being able to come into contact with a copy sheet on one stretch side of the transfer belt to convey the copy sheet in a direction from the first roller to the second roller. The cleaning device is provided with a cleaning blade member for removing toner from the belt. The cleaning blade member is disposed on the other stretch side of the transfer belt and near the second roller, being pressed perpendicularly against an outside surface of the belt, and having a leading end portion which is flexed and capable of coming into a line contact with the belt over an entire width of the belt when the belt is driven. The amount of pressing force of the blade against the belt will be adjusted depending on the sensed temperature of the belt.

Cleaning device for a transfer belt of an image forming apparatus

A transfer plate which also serves as a sheet guide plate is pushed by a torsion spring. A minimum gap less than 0.2 mm between a guide surface of the transfer plate and the surface of a photoreceptor drum is maintained to be smaller than the thickness of a transfer sheet by a spacer member provided on the guide surface. When the sheet passes through the gap between the drum surface and the guide surface, the transfer plate is pushed down by the sheet and the sheet is pressed onto a toner image formed on the drum surface with an appropriate pressure by the pushing force of the torsion spring. At this time, a transfer voltage is applied to the transfer plate, so that the toner image on the drum surface is transferred to the sheet.

Image transfer unit for image forming apparatus

An image-transfer and sheet-separating apparatus transfers an image toner-developed from a positive latent image and retained on a photoconductor drum onto a copy sheet, and subsequently separates the sheet from the photoconductor drum. A sheet peel-separating AC voltage and an image-transferring DC bias voltage is applied to a transfer roller which presses on the photoconductor drum. The AC voltage is applied to the transfer roller when a transport-forward end of the sheet is located between the transfer roller and the photoconductor drum, and subsequently the DC voltage is applied to the transfer roller. A post image-transfer charge-stripping element removes charge from the copy sheet and is disposed in a portion of the sheet-transport stream forward of a nipping position at which the transfer roller presses against the photoconductor drum. Thus, charge remaining on the copy sheet is discharged, ensuring high efficiency in image transfer and accordingly reducing the incidence of failure in the separation of the copy sheet from the photoconductor drum.

An image forming apparatus includes an electric charge removing device for elastically coming in contact with a photoreceptor when there is no paper and for removing electric charges from the paper which is delivered, and a control device for starting to apply voltage to a transferring roller at a timing which is earlier by a predetermined time than a timing when the leading edge of the paper arrives at a transferring position and for releasing the application of the voltage to the transferring roller at a timing which is later by a predetermined time than a timing at which the trailing edge of the paper passes through the transferring position.

Image forming apparatus

A sheet member conveying device is equipped with an endless sheet member conveyor belt composed of a semiconductor material and an electrical charging device which electrically charges the sheet member conveyor belt in order to transfer a toner image formed on the surface of a rotary drum onto a sheet member at a toner image transfer position. The sheet member conveyor belt is put around a plurality of rollers and moves from the toner image transfer position toward a sheet member peeling position. A grounding device is provided between the toner image transfer position and the sheet member peeling position along the sheet member conveyor belt in order to decrease the surface potential which is due to the charge of the sheet member conveyor belt.

Sheet member carrier device with grounding means

A transfer device for use in an image forming apparatus provided with a photosensitive drum on which a toner image is formed, the transfer device including a transfer member which is charged to transfer the toner image formed on the photosensitive drum to a copy sheet, a cleaner for cleaning toner depositing on the transfer member, and a power supply unit for applying a voltage to the cleaner to charge the transfer member, the cleaner being constructed so as to produce a potential difference between the cleaner and transfer member to attract the toner depositing on the transfer member. Accordingly, the transfer device of the invention is allowed to have a more simplified construction compared to existing transfer devices.

Transfer device for use in an image forming apparatus

A toner cleaning apparatus for removing a toner left on the surface of an electrophotographic photosensitive material by a doctor blade in the electrophotographic process includes an elastic doctor blade having a toner-scraping top end, a holder for supporting the base of the doctor blade, a fulcrum for swingably supporting the holder and a pressing mechanism for pressing the top end of the doctor blade to the surface of the photosensitive material, wherein the fulcrum and doctor blade are arranged so that on the feed-out side of the photosensitive material, the contact angle .alpha. between the top end of the doctor blade and the photosensitive material is smaller than the angle .beta. between the photosensitive material and the line connecting the top end of the doctor blade to the fulcrum, and the pressing mechanism and doctor blade are arranged in such an elastic engagement relation that as the applied stress is increases, the top end of the doctor blade is retreated to the feed-out side and the degree of flexion of the doctor blade is increased.

Growing community of inventors

Osaka, Japan

Ryuji Wataki