摘要:
An developer for developing a latent image with a developing agent such as toner. The developer includes a developing sleeve for holding the developing agent on its surface, in which magnetic poles are provided in the developing sleeve; a equalizer bar for equalizing the amount of the developing agent on the surface of the developing sleeve; a pressing member to press the equalizer bar onto the developing sleeve. In the developer, a radius of curvature of the equalizer bar is between 0.5 mm and 15 mm, and the developing sleeve is processed to have a jagged surface which is defined by a glossiness between 2% Gs and 1400% Gs (20.degree.).
摘要:
An optical system assembling method in an image forming apparatus in which there are provided an image forming body around which a plurality of exposure device each having a linear exposure optical system to imagewise expose on the image forming body, and a plurality of developing device containing respective color toners different from each other which are superimposed on the image forming body to form a color toner image, the method further having the steps of: lighting the exposure optical system; forming an image emitted from the exposure optical system on a sensor which is disposed at a position corresponding to a photosensitive surface of the image forming body with respect to the exposure optical system; adjusting a position of the exposure optical system on the basis of a result of the image forming so that a focal point of the exposure optical system is coincident with a surface of the sensor; and fixing at the adjusted position the exposure optical system to an optical system supporting body provided on a main body of the apparatus.
摘要:
An image forming apparatus includes: a photoreceptor drum; a charger for charging an outer surface of the photoreceptor drum; image exposure devices each for exposing the photoreceptor drum to form a latent image thereon, wherein the image exposure devices are provided inside the photoreceptor drum, and are detachably mountable with the photoreceptor drum to the image forming apparatus; a developing device for developing the latent image to form a toner image on the outer surface of the photoreceptor drum; and a supporting member on which the image exposure devices are mounted, wherein the supporting member and the photoreceptor drum are connected through bearing members on both ends of the photoreceptor drum, and the supporting member has an engaging portion for engaging with a part of the image forming apparatus to fix the image exposure devices through the supporting member, while the photoreceptor drum is rotated around the image exposure devices through the bearing members.
摘要:
A color image forming apparatus provided with plural charging devices, plural image exposure devices, and plural developing devices which are arranged around the outer circumference of a photoreceptor so that a color image is formed during a single rotation of the photoreceptor. The apparatus comprises a supporting cylinder for enclosing the photoreceptor and for supporting the plural image exposure devices thereon.
摘要:
A color image forming apparatus includes a photoreceptor drum having an outer diameter of 50 mm to 100 mm and a rotational axis, four charging devices for charging the photoreceptor drum, and four exposure devices, provided inside the photoreceptor drum, for imagewise exposing an inner surface of the photoreceptor drum to form respective four latent images. Four developing devices are provided outside the photoreceptor drum at an upper section thereof for developing respective ones of the four latent images using respective different one-component type color developers to form four different color toner images in a superimposed manner on an outer surface of the photoreceptor drum during one rotation thereof the photoreceptor drum. Each developing device has a developing roller for conveying the respective one-component type developers to the outer surface of the photoreceptor drum, and the four developing devices are arranged along an outer circumference of the photoreceptor drum in a manner such that a rotational axis of each of the developing rollers is located within a central angle of 180.degree.. In addition, a transfer device is provided at a lower section of the photoreceptor drum for transferring the superimposed four different color toner images from the outer surface of the photoreceptor drum to a sheet. The transfer device includes an inlet sheet passage and an outlet sheet passage, and the outlet sheet passage is arranged either coplanar with the inlet sheet passage or inclined with respect to the inlet sheet passage at an angle between 10.degree. above the inlet sheet passage and 30.degree. beneath the inlet sheet passage.
摘要:
A color image forming apparatus includes a plurality of chargers, imagewise exposure devices and developing devices. During a single rotation of an image forming body, a sequence of charging, exposing and developing is repeated to superimpose toner images, and then the toner images are transferred onto a recording medium. Each exposing position on a circumferential surface of the image forming body is arranged downstream of a developer casing and upstream of a line connecting the centers of the image forming body and developing sleeve. The following expression is satisfied: L.sub.1 >L.sub.2 >vT+w where L.sub.1 represents a circumferential distance along the periphery of the image forming body between the line connecting the rotational center of the image forming body and the tip end of the developing casing and a line connecting the rotational center of the image forming body and the rotational center of the developing sleeve; L.sub.2 represents a circumferential distance along the periphery of the image forming body between the exposing position and the line connecting the rotational center of the image forming body and the rotational center of the developing sleeve; w represents a width of a developing area upstream of a position, where a gap between a peripheral surface of the image forming body and a peripheral surface of the developing sleeve is minimum; T represents a decay time of a potential on the image forming body after imagewise exposing is conducted; and v represents a circumferential speed of the image forming body.
摘要:
This invention relates to an image forming apparatus which employs a recycling scheme of recovering and reusing transfer residue toner, and a convey control method for recycle toner. In order to prevent a phenomenon such as fogging or character thickening, a toner recycle mechanism shares one driving source with a photosensitive body or fixing unit, and includes an electromagnetic clutch for switching driving force transmission to the recycling means when driving the photosensitive body or fixing unit, and a controller which controls power supply to the electromagnetic clutch. The convey control method for recycle toner includes the steps of starting copying, measuring a printing ratio of an image pattern per image, and suppressing a return amount of the recycle toner when the printing ratio of the image pattern is low.
摘要:
In a fixing apparatus for fixing toner images on a transfer material upon which toner images have been placed by applying heat to the transfer material, the fixing apparatus includes: a roll-shaped rotary member for applying heat to the transfer material upon which toner images have been placed, the roll-shaped rotary member including a cylindrical ray-transmitting base member, and a ray absorbing layer for generating heat onto the transfer material upon which toner images have been placed so as to fix the toner on the transfer material, the ray absorbing layer, provided on an outer side of the ray-transmitting base member; a ray irradiating device for irradiating ray to the ray absorbing layer, the ray irradiating device provided inside the cylindrical ray-transmitting base member; bearing member for rotatably supporting the roll-shaped rotary member; flange members provided on both ends of the ray-transmitting base member; and an elastic covering member provided between the flange member and the roll-shaped rotary member for joining each member.
摘要:
An image forming apparatus having an exposure optical system provided with an exposure light source in which light-emitting elements are arranged on a base plate to be line-shaped and with a lens array of a distributed refractive index type that converges a beam emitted from the exposure light source on the surface of a photoreceptor and conducts imagewise exposure. The apparatus is configured to satisfy the expression: ##EQU1## In the expression, .DELTA.T1 represents a variation width (K) of the temperature in the vicinity of light-emitting elements, R represents a radius of the photoreceptor mentioned above, Ri represents a length (.mu.m) of each member constituting the exposure optical system in the radial direction of the photoreceptor, .alpha. represents a coefficient of linear thermal expansion (.degree.C..sup.-1) of a transparent base that forms the photoreceptor, .alpha.i represents a coefficient of linear thermal expansion (.degree.C..sup.-1) of each member that constitute the exposure optical system, and F represents the depth of focus (.mu.m) of the lens array.
摘要:
A color image forming apparatus includes a drum type image forming body; four charging devices for charging the image forming body; four exposure devices fixed on the main body for imagewise exposing the charged image and forming body to form a latent image; four developing devices each for developing the latent image to form a different colored toner image. After operations by the charging devices, the exposure devices and the developing devices are repeated to superimpose the different colored toner images on the image forming body, the superimposed colored toner images are transferred by a transfer device including an intermediate transferring member and a transfer member in contact with the intermediate transferring member onto a recording material at one time. Two developing devices are disposed at left and right positions, respectively, with respect to a vertical line passing through a center of the image forming body, and another two developing devices are disposed at upper and lower positions, respectively, with respect to a horizontal line passing through the center of the image forming body.