Abstract: A sheet conveyance device includes a pair of separable contact rollers configured to convey a sheet, a contact/separation mechanism configured to support the pair of separable contact rollers in such a manner that the pair of separable contact rollers are able to come into separable contact with each other, and a solenoid configured to operate the contact/separation mechanism. The solenoid is driven so that the contact/separation mechanism causes the pair of separable contact rollers to come into pressure contact with each other, and driving of the solenoid is cancelled so that the contact/separation mechanism causes the pair of separable contact rollers to be separated from each other. Pulse width modulation duty control is performed on the solenoid while the pair of separable contact rollers are in pressure contact with each other when a plurality of the sheets are conveyed one by one at an interval.

Abstract: A sheet transporting device in which a curved transport path is provided downstream in a sheet transport direction from a merging section where a plurality of transport paths, which are formed by transport guides for transporting sheets, merge, is provided. The sheet transporting device includes a sheet guide member that extends towards the curved transport path from the merging section, with an extending end portion of the sheet guide member being disposed so as not to contact the transport guides. The sheet guide member reduces jumping up of a trailing end portion of a sheet caused by flexing of the sheet passing through the merging section towards the curved transport path.

Abstract: A sheet feed apparatus includes a sheet separation unit, and the sheet separation unit includes a separation roller that is provided so as to be brought into contact to an outer peripheral surface of a sheet feed roller, and separates a sheet fed by the sheet feed roller into one. The sheet separation unit comprises a hook for rotatably supporting the sheet separation unit in a main body casing of the sheet feed apparatus and an engaging claw that makes the sheet separation unit engage with the main body casing. Therefore, the sheet separation unit is held in the main body casing detachably.

Abstract: A sheet conveyance device includes a pair of separable contact rollers configured to convey a sheet, a contact/separation mechanism configured to support the pair of separable contact rollers in such a manner that the pair of separable contact rollers are able to come into separable contact with each other, and a solenoid configured to operate the contact/separation mechanism. The solenoid is driven so that the contact/separation mechanism causes the pair of separable contact rollers to come into pressure contact with each other, and driving of the solenoid is cancelled so that the contact/separation mechanism causes the pair of separable contact rollers to be separated from each other. Pulse width modulation duty control is performed on the solenoid while the pair of separable contact rollers are in pressure contact with each other when a plurality of the sheets are conveyed one by one at an interval.

Abstract: A sheet transporting device in which a curved transport path is provided downstream in a sheet transport direction from a merging section where a plurality of transport paths, which are formed by transport guides for transporting sheets, merge, is provided. The sheet transporting device includes a sheet guide member that extends towards the curved transport path from the merging section, with an extending end portion of the sheet guide member being disposed so as not to contact the transport guides. The sheet guide member reduces jumping up of a trailing end portion of a sheet caused by flexing of the sheet passing through the merging section towards the curved transport path.

Abstract: A document feeding device of the present invention includes: a discharge roller pair that includes a first drive roller and a first idler roller; and a transport roller pair that includes a second drive roller and a second idler roller. Either one of the second drive roller and the second idler roller moves between a contact position where said roller is in contact with the other roller and a separation position where said roller is separated from the other roller. The transport roller pair is disposed on the other side of the discharge roller pair from a discharge tray. The transport roller pair transports a document that has passed through the reading position to the discharge roller pair by positioning said roller at the contact position in a case where the first drive roller rotates forward.

Abstract: An image reading apparatus includes a reading glass, a second guide member, and a control section. The reading glass and the second guide member together form a document feed path. The second guide member includes a white reference plate. The control section performs, when it is determined that shading correction image data is affected by a stain, a stain location determination of whether the stain is attached to the reading glass or the second guide member according to a tone value variation in the portion of the shading correction image data that corresponds to the stain edge, the variation being along a predetermined distance in the main scanning direction.

Abstract: A sheet carrying apparatus, being applicable in (i) an automatic document feeding apparatus and/or (ii) paper feeding and conveying mechanism of an image forming apparatus, has an opening in that part of a curved guiding surface of a lower conveyance guide of a sheet conveyance guiding section constituting a curved conveyance path, which receives a front end of a document fed to the curved conveyance path. The opening has such a size in a guide width direction orthogonal to a document conveying direction, which is passable for a small size sheet not larger than a predetermined size. With this, the small size sheet passed through the opening is sorted out.

Abstract: A document feeding device of the present invention includes: a discharge roller pair that includes a first drive roller and a first idler roller; and a transport roller pair that includes a second drive roller and a second idler roller. Either one of the second drive roller and the second idler roller moves between a contact position where said roller is in contact with the other roller and a separation position where said roller is separated from the other roller. The transport roller pair is disposed on the other side of the discharge roller pair from a discharge tray. The transport roller pair transports a document that has passed through the reading position to the discharge roller pair by positioning said roller at the contact position in a case where the first drive roller rotates forward.

Abstract: An image reading apparatus includes a reading glass, a second guide member, and a control section. The reading glass and the second guide member together form a document feed path. The second guide member includes a white reference plate. The control section performs, when it is determined that shading correction image data is affected by a stain, a stain location determination of whether the stain is attached to the reading glass or the second guide member according to a tone value variation in the portion of the shading correction image data that corresponds to the stain edge, the variation being along a predetermined distance in the main scanning direction.

Abstract: An image reading apparatus of the present invention includes a photoelectric transducer that performs reading scanning along a main scanning line and reads an original, the image reading apparatus obtaining a white shading level of pixels based on an output level of the photoelectric transducer obtained when a reference white is read, obtaining a black shading level of the pixels based on an output level of the photoelectric transducer obtained when a black reference is read or obtained in a dark condition, and correcting the output level of the photoelectric transducer obtained when an original image is read with the use of the white shading level and the black shading level, and the image reading apparatus further comprising a correction unit that obtains a variation amount of the white shading level between a pixel and other pixels in the vicinity of that pixel for each of pixels on the main scanning line, determines whether the variation amount exceeds a pre-set threshold value, and when the correction un

Abstract: A sheet carrying apparatus, being applicable in (i) an automatic document feeding apparatus and/or (ii) paper feeding and conveying mechanism of an image forming apparatus, has an opening in that part of a curved guiding surface of a lower conveyance guide of a sheet conveyance guiding section constituting a curved conveyance path, which receives a front end of a document fed to the curved conveyance path. The opening has such a size in a guide width direction orthogonal to a document conveying direction, which is passable for a small size sheet not larger than a predetermined size. With this, the small size sheet passed through the opening is sorted out.

Abstract: A sheet carrying device has a mechanism that prevents a sheet from being fed backward into a carriage path after once discharged from the device, and the sheet carrying device includes a carriage surface that guides a sheet, a reverse roller attached to a rotation shaft of a sheet discharging portion, whose rotation direction is switchable between forward and backward, and a backward-feed prevention valve that prevents an edge of a discharged sheet from entering into a nip portion of the reverse roller, and the backward-feed prevention valve includes a resin sheet and an elastic member disposed at one end on the sheet discharging side of the resin sheet, and the elastic member has one surface supported by the rotation shaft of the reverse roller and the other surface pressing the resin sheet against the carriage surface.

Abstract: A document reader includes an exterior panel covering a region of a document feed path including a second image read position from outside. The document reader also includes a first open/close member forming a region of the exterior panel including a portion opposed to the image read position. The document reader further includes a second open/close member positioned inwardly of the first open/close member to define a region of the document feed path including the image read position. The first and second open/close members are supported at respective different fulcrums for opening/closing movement about respective shafts extending perpendicularly to the document feed direction, thereby shielding the second image read position from extraneous light.

Abstract: A sheet carrying device has a mechanism that prevents a sheet from being fed backward into a carriage path after once discharged from the device, and the sheet carrying device includes a carriage surface that guides a sheet, a reverse roller attached to a rotation shaft of a sheet discharging portion, whose rotation direction is switchable between forward and backward, and a backward-feed prevention valve that prevents an edge of a discharged sheet from entering into a nip portion of the reverse roller, and the backward-feed prevention valve includes a resin sheet and an elastic member disposed at one end on the sheet discharging side of the resin sheet, and the elastic member has one surface supported by the rotation shaft of the reverse roller and the other surface pressing the resin sheet against the carriage surface.

Abstract: An image reading apparatus is provided with a first image reading unit and a second image reading unit. The first image reading unit reads an image on a first side of a document that is transported in a predetermined direction on a document transport path, at a first image reading position. The second image reading unit reads an image on a second side of the document that is transported in the predetermined direction on the document transport path, at a second image reading position. A transport roller and a bent portion of the document transport path are arranged in this order along the document transport direction upstream of each of the first image reading position and the second image reading position in the document transport direction.

Abstract: A document reader includes an exterior panel covering a region of a document feed path including a second image read position from outside. The document reader also includes a first open/close member forming a region of the exterior panel including a portion opposed to the image read position. The document reader further includes a second open/close member positioned inwardly of the first open/close member to define a region of the document feed path including the image read position. The first and second open/close members are supported at respective different fulcrums for opening/closing movement about respective shafts extending perpendicularly to the document feed direction, thereby shielding the second image read position from extraneous light.

Abstract: An image reading apparatus is provided with a first image reading unit and a second image reading unit. The first image reading unit reads an image on a first side of a document that is transported in a predetermined direction on a document transport path, at a first image reading position. The second image reading unit reads an image on a second side of the document that is transported in the predetermined direction on the document transport path, at a second image reading position. A transport roller and a bent portion of the document transport path are arranged in this order along the document transport direction upstream of each of the first image reading position and the second image reading position in the document transport direction.

Abstract: An image forming unit includes: a toner support for supporting the toner; an opposing electrode opposed to the toner support; a high-voltage power source for supplying a high voltage to produce a potential difference between the toner support and the opposing electrode; a control electrode having an insulative substrate disposed between the developer support and the opposing electrode, a plurality of gates formed in the insulative substrate for forming the passage of the developer, and electrode groups provided around a multiple number of the gates; and a control device for selectively applying multiple potential states to each electrode in the control electrode, wherein the control device controls the passage of the developer through the gates by applying the predetermined voltage to electrode groups so as to form an image on the surface of the paper which is being conveyed over the opposing electrode.

Abstract: An image forming apparatus includes an opening and closing member mounted to an apparatus main body so that it can be open and closed, and a head cover for protecting the surface of a control electrode when opening the opening and closing member without disturbing an operation of controlling the flying of a toner by the control electrode in a closed state of the opening and closing member as being moved interlocking with opening and closing operations of the opening and closing member. According to the described arrangement, when the opening and closing member is open to remove a jammed sheet, exchange a toner cartridge, carry out various checking for printing inferior or install and remove a unit including the control electrode with respect to the apparatus main body, the control electrode which would be exposed otherwise can be prevented from being touched with an operator's finger or other member of the apparatus, etc.