Canon Kabushiki Kaisha

Akinori Tanaka

Fumitake Hirobe

Akihiro Noguchi

Tadayoshi Nishihama

Ryoichi Kawasumi

Teppei Nagata

Yuichiro Toyohara

Takuya Terae

An image forming apparatus includes an image bearing member to form a toner image on a recording material with a liquid developer containing a toner and a carrier liquid, wherein the carrier liquid contains a first substance, charged to an opposite polarity to a charge polarity of the toner, for imparting an electrical polarity to the toner, and a second substance, higher in volume resistivity than the first substance, a cleaning portion to collect the liquid developer remaining on the image bearing member after the toner image is transferred onto the recording material, a toner separating device to separate the collected liquid developer into the toner and the carrier liquid, and a carrier separating device to separate the carrier liquid into the carrier liquid containing the first substance and the carrier liquid containing the second substance by applying an electric field to the carrier liquid.

Image forming apparatus and carrier separating device

The present invention includes an image forming unit, a reversing unit configured to reverse the sheet on which the image has been formed by the image forming unit, a reconveyance path which conveys the sheet reversed by the reversing unit to a feeding path for forming an image on the sheet by the image forming unit again, a position detection unit which is provided on the reconveyance path and configured to detect a position of the sheet in a width direction, a skew-feeding correction unit which is provided on the reconveyance path and configured to correct skew-feeding of the sheet, wherein the position detection unit is disposed on the downstream of the skew-feeding correction unit in reconveyance path, wherein the image forming unit corrects the position of the image to be formed on the sheet, which is conveyed through the reconveyance path, based on a signal from the positioning detection unit.

Image forming apparatus

In an image forming apparatus having a developing rotary, when a positive direction refers to a circumferential direction of the developing rotary in which the portion of the developing rotary facing a photosensitive drum moves in the same direction as the movement of the circumference of the photosensitive drum, a clear developing unit is farther from the developing unit positioned in the negative direction relative to the clear developing unit than from the developing unit positioned in the positive direction relative to the clear developing unit.

Image forming apparatus having mechanism for preventing mixing of scattered toner between adjacent developing units

An image forming apparatus includes color developing units for development with color developing agents, a transparence developing unit for development with a transparent developing agent, a rotary member which holds and rotationally moves the color and transparence developing units toward a development position, a driving device which rotationally drives the rotary member, a toner accumulation portion arranged below the rotary member in a gravity direction, falling toner accumulating therein, and a controller capable of starting image formation after the rotary member is moved to a reference position for rotation start. When the rotary member is located at the reference position, stop control thereof is performed such that at least one color developing unit is located in a region arranged downstream of the transparence developing unit and upstream of a lowermost portion of the rotary member in the gravity direction, with reference to the rotation direction of the rotary member.

Image forming apparatus wherein, when a rotary member is located at a reference position, a color developing device is located in a region extending from a position of a transparent developing device toward a downstream side of a rotation direction of the rotary member to a lowermost point in the gravity direction of the rotary member

An image forming apparatus includes: an image bearing member, on which an electrostatic image is formed; a development unit which is provided with a developer bearing member for bearing and conveying a developer, so as to develop the electrostatic image; a storage place which can store therein the developer spattering from the development unit; a shielding member which is disposed in a region outside of a development region in the storage place; and a foreign material collecting member which is disposed in a region farther outside of the shielding member in the storage place.

An image forming apparatus includes an image bearing member on which an electrostatic image is formed by imagewise exposure; a rotatable member; a developing device carried on said rotatable member and movable, by rotation of said rotatable member, to a developing position where said developing device is opposed to said image bearing member; a driven gear which is provided in said developing device and which receives a driving force for operating said developing device; and a driving gear, provided in a main assembly of the apparatus, for driving engagement with said driven gear of said developing device which is located at the developing position, wherein said driving gear, when said developing device is moving toward the developing position, is driven such that moving direction thereof is the same as a moving direction of said driven gear at an engagement portion with said driven gear, wherein upon driving engagement between said driven gear and said driving gear, a peripheral speed VA of said driven gear which is being moved by said rotatable member on an addendum circle thereof at said engagement portion and a peripheral speed VB of said driving gear on an addendum circle thereof satisfy 0.9&#x2266;VA/VB&#x2266;1.0.

Image forming apparatus with driving and driven gears

A developing apparatus includes a developer container for containing a developer; a first screw, provided in a first screw, provided in a first chamber in the developer container, for feeding the developer; a second screw, provided in a second chamber in the developer container, for feeding the developer in a direction opposite from that of the first screw; an opening through which the developer is moved between the first chamber and the second chamber; and a developer carrying member, provided in the first chamber, for carrying the developer to effect development of an electrostatic image. At least one of said first screw and said second screw has a multiple thread screw portion having a number n of threads and a thread pitch P. The opening is located downstream from the multiple thread screw portion in a developer feeding direction and extends from a downstream-side end of the multiple thread screw portion in the developer feeding direction toward an upstream side of the multiple thread screw portion in a length equal to or more than nP.

Developing apparatus

In a developing apparatus provided with a developer container containing a developer, a rotary member holding the developer container and rotatively moving it relative to a developing position, an opening portion provided in the developer container and through which the developer is supplied or discharged, a valve swingable to open and close the opening portion, and a restricting wall restricting the movement of the valve in an opening direction by contacting with the valve when the valve is in an opened position, an irregularity portion is provided on at least one of the contact surface of the valve with the restricting wall and the contact surface of the restricting wall with the valve.

Developing apparatus and image forming apparatus

Image forming apparatus featuring reduced shock attributable to a speed difference between a driving gear and a driven gear of a developing device

The image forming apparatus includes a developing device, a movable member, a replenishment device, a developer replenishment path, and a conveyance screw so arranged within the developer replenishment path as not to come into contact with the internal wall of the developer replenishment path, wherein X (g) representing the quantity of the developer for replenishment present in the clearance section between the developer replenishment path and the conveyance screw, Y (g) representing the quantity of the developer in the developing device, Q(&#x3bc;C/mg) representing the absolute value of the electric charge per unit weight of the toner in the developing device, and A(&#x3bc;C/mg) representing the absolute value of the electric charge per unit weight of the toner relative to a 1% variation in the toner density satisfy the condition of a relationship of X&#x2266;(Y&#xd7;Q)/(500&#xd7;A).

Image forming apparatus having movable developing devices and developer replenishment device

The developing apparatus includes developer containing parts and a replenishment portion. The developer containing parts contains a developer circularly conveyed in the developer containing parts. The replenishment portion includes a replenish aperture and a regulation surface. The replenishment portion merges a replenishment agent passing through the regulation surface with the developer in the developer containing part. In the developing apparatus, a wall surface of the replenishment portion, located on a downstream side in a developer conveyance direction in the developer containing part facing to the replenishment portion, is formed by being inclined with respect to the developer conveyance direction.

Developing apparatus for image forming apparatus

A developing apparatus for developing an electrostatic image on an image bearing member includes a rotary member including a plurality of mounting portions, to which a plurality of developing devices and a plurality of balance weights are detachably mountable. The rotary member selectively shifts a mounted developing device to a developing position opposite to the image bearing member. A developing process is performed in a first mode in which developing devices are attached to all the mounting portions, and in a second mode in which a developing device is mounted to at least one of the mounting portions, and no developing devices are mounted to the remaining mounting portions, and wherein, in the second mode, balance weights are mounted to the remaining mounting portions. An image forming apparatus includes an image bearing member and the developing apparatus.

Developing apparatus including rotary member for accommodating variable combinations of developing sleeves and balance weights

In case a fixing speed is lower than a transferring speed, the individual conveyor units are controlled such that, while a downstream conveyor unit () is conveying a sheet (S) being fixed at the same speed (V) as the fixing speed, an upstream conveyor unit () may convey the succeeding sheet (S) at the same speed (V) as the transferring speed. As a result, the spacing of the two sheets in a fixing unit () can be sufficiently narrowed to improve the image forming efficiency. Moreover, the transferring speed need not be decelerated according to the fixing speed. It is, therefore, possible to prevent the deterioration in the image quality and to shorten the image forming time period of the first sheet.

Image forming apparatus including plural conveyor units with conveyance path length/conveyance speed relationships

The image forming apparatus is equipped with a first photosensitive member, a plurality of first developing devices, a second photosensitive member, and a second developing device. In the image forming apparatus, toner images on the first photosensitive member and the second photosensitive member are transferred onto a transfer medium while one is superimposed on the other, whereby it is possible to form a high quality image using deep-color and light-color toners of the same hue and to prevent a deterioration in gradation property.

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Abiko, Japan

Akinori Tanaka