Kabushiki Kaisha Toshiba

Naruhito Yoshida

Takashi Shiraishi

Ken Omura

Kazuhiko Kikuchi

Masao Yamaguchi

Toshihiro Kasai

Jiro Egawa

Naoaki Ide

Mitsuaki Kohyama

Hironobu Machida

Moriya Nagasawa

Rintaro Nakane

Osamu Takagi

Minoru Yoshida

Koji Tanimoto

Tadayoshi Ohno

Kunihiko Miura

Kouji Hirano

Shinya Tomura

Capacitors 32 connected to their corresponding matrix-shaped picture elements 33 are connected to an image forming unit 20 on which an electrostatic latent image is formed. Switching elements 31 are also connected to the image forming unit 20. When the switching elements 31 are made conductive, their corresponding capacitors 32 are charged from a power source arranged outside, and a potential appears in each of their corresponding picture elements 33. Therefore, the electrostatic latent image can be more stably formed on these matrix-shaped picture elements over a time period which is determined by time constant. AS the result, electrostatic latent image formation can be achieved without using any ozone-generating pre-charger. In addition, the electrostatic latent image forming unit can keep its toner holding force even after the developing process to enable an image to be more reliably and clearly reproduced.

Image forming apparatus using an electrode matrix to form a latent image

A transfer roller is provided near a developing roller which is set, at a relative speed of substantially zero, in contact with a photosensitive drum to develop an electrostatic latent image on the photosensitive drum into a visual image. A toner transfer roller supplies a toner, that is, a one-component developing agent which is stored in a toner storage section to the developing roller and receives that toner which is unspent upon development from the developing roller. The unspent toner transferred to the toner transfer roller is brought into abutting contact with a mesh network of a toner separating member to separate the toner from the toner transfer roller over a predetermined effective length. By so doing it is possible to erase a developing hysteresis from the developing roller and, at the same time, collect the toner back into the toner storage section so that the collected toner is mixed with a fresh toner for use at the next developing cycle.

Developing apparatus including means for collecting used developing agent

A device for developing a latent image on an image carrier is used in an image forming apparatus. The developing device includes a developing roller, located to contact with the image carrier, for supplying a developing agent to the image carrier, and a blade, located to face the developing roller, for forming a developing agent layer of the developing agent supplied to the image carrier on the developing roller. The developing roller comprises an urethane rubber layer and a conductive urethane resin layer located around the rubber layer, in which the thickness T [.mu.m] of the conductive resin layer satisfies the formula, 3.times.Rz=T=1OO when the maximum surface roughness of the rubber layer is taken in Rz [.mu.m]. in addition, the respective elongations (%) of the rubber and resin layers L.sub.e and L.sub.1, satisfy the formula L.sub.e -L.sub.1 .ltoreq.200.

Developing device using developing roller having specific structure

An optical deflector is employed in an optical unit incorporated in a laser beam printer. The optical deflector reflects a laser beam, which is generated by a laser diode toward a photosensitive body and is made to have a cross section of desirable size by a group of conversion lenses. The optical deflector is provided with reflecting surfaces whose cross sections are convex in a main scanning direction. The number of reflecting surfaces is defined by 4.times.m (m: a natural number), and therefore the optical deflector has four or eight reflecting surfaces, for instance. Since the number of reflecting surfaces is defined by 4.times.m, reflecting surfaces can be positioned easily and reliably with reference to the center of the shaft.

Optical deflector device for deflecting laser beam

An image forming apparatus has a disordering device for disordering the developing agent remaining on the image bearing member after transfer of the developed image by the transfer device. The disordering device includes a conductive member positioned to rub against the image bearing member, for attracting the developing agent remaining on the image bearing member and distributing the attracted developing agent on the image bearing member so as to disorder any pattern therein. The disordering device of the present invention also has a contact member which is positioned between the disordering device and the charger, for leveling any deposits of the developing agent remaining on the image bearing member. The contact member is in sliding contact with the surface of the image bearing member in the same direction as the rotation of the image bearing member.

Image forming apparatus having a disordering device for disordering a

In an optical unit used for a laser beam printer, a laser beam generated by a laser diode is converted by a group of conversion lenses into a laser beam having a predetermined-size cross section. The laser beam is directed toward a photosensitive body by a scanner. A focusing lens allows the rotating angle of the reflecting faces of the scanner to correspond to a desirable point on the surface of the photosensitive body. In other words, the rotating angle is made to correspond to the distance between the optical axis center determined with respect to a main scanning direction and a point to which the laser beam is irradiated for scanning. The conversion lenses includes at least one aspheric glass lens arranged close to the laser diode. The glass lens and the laser diode are integrally held by a lens barrel which linearly expands in a predetermined manner in response to a temperature change. Since the distance between the glass lens and the laser diode is constantly equal in accordance with the temperature change, the laser beam is constantly allowed to have a cross section of desirable size, without reference to the temperature change.

Optical unit for use in laser beam printer or the like with temperature

An image forming apparatus having a humidity detector which is detachably attached to the main apparatus body that accommodates an image forming member. The humidity detector detects a humidity in the vicinity of the image forming member, converts the detected humidity into a relative humidity and outputs it. Based on the value of the output relative humidity, image forming conditions, such as the amount of exposure, are set. The humidity detecting unit contains a time detecting unit for detecting the time for replacement.

Image forming apparatus with a humidity detector

An image forming apparatus for forming a toner image on a recording medium. The apparatus includes a photosensitive drum on which a latent image is formed, a developing/cleaning device for developing the latent image with a developing agent and for removing the developing agent remaining on the photosensitive drum therefrom while the latent image is developed, and a transfer device for transferring the developed image on the photosensitive drum to the sheet. The apparatus further includes a disordering device for disordering the developing agent remaining on the photosensitive drum, after transfer of the developed image by the transferring means, to render the developed image nonpatterned. The disordering device includes a contact member having projections and depressions formed with a prescribed inclined angle relative to the direction intersecting at right angles the rotating direction of the photosensitive drum at the contact portion with the photosensitive drum.

Image forming apparatus

In an optical unit used for a laser beam printer, a laser beam generated by a laser diode is converted by a group of conversion lenses into a laser beam having a predetermined-size cross section. The laser beam is directed toward a photosensitive body by a scanner, so as to scan the photosensitive body at a constant speed. A focusing lens allows the rotating angle of the reflecting faces of the scAnner to correspond to a desirable point on the surface of the photosensitive body. In other words, the rotating angle is made to correspond to the distance between the optical axis center determined with respect to a main scanning direction and a point to which the laser beam is irradiated for scanning. The focusing lens is arranged between the scanner and the photosensitive body and shapes the laser beam reflected by the scanner such that the laser beam has a desirable diameter. The focusing lens has a toric surface which is formed on the side closer to the scanner than the other and which is rotation-symmetric with reference to an axis extending in the main scanning direction. The cross sectional shape of the focusing lens is concave in a plane expanding in the main scanning direction and is convex in a plane expanding in a sub-scanning direction.

Optical unit for use in laser beam printer or the like

In an optical unit incorporated in a laser beam printer, a laser beam generated by a laser diode is converted by a group of conversion lenses into a laser beam having a predetermined-size cross section. The laser beam is directed toward a photosensitive body by a scanner unit, so as to scan the photosensitive body. A focusing lens allows the rotataing angle of the reflecting faces of the scanner unit to correspond to a desirable point on the surface of the photosensitive body. In other words, the rotating angle is made to correspond to the distance between the optical axis center determined with respect to a main scanning direction and a point to which the laser beam is irradiated for scanning. The conversion lenses include at least one aspheric glass lens. The conversion lenses further includes a pair of plastic lenses which have substantially the same power and opposite polarities with respect to either the main scanning direction or a subscanning direction. Among the lenses mentioned above, that lens which is located closest to the glass lens is integral with the laser diode. The focusing lens is formed of a material having substantially equivalent characteristics to those of the paired plastic lenses.

An optical deflector is employed in an optical unit incorporated in a laser beam printer. The optical deflector reflects a laser beam, which is emitted by a laser diode and is made to have a cross section of desirable size by a group of conversion lenses, toward a photosensitive body. The optical deflector contains a polygonal mirror having four or eight reflecting surfaces. Each of these reflecting surfaces has a cross section which is convex in a main scanning direction. The polygonal mirror is adhered to the shaft of a motor used for rotating the polygonal mirror. Alternatively, it is adhered to the base member fixed to the shaft.

A recording apparatus according to the present invention in which a data is recorded by charging a recording medium, scanning laser beams on the recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode. And, the driver for driving the recording medium is controlled so as to continuously drive the recording medium when the first print mode is switched to the second print mode by the switching device. The image forming device comprises device for forming an electrostatic latent image on the recording medium by scanning laser beams in accordance with the recording data and device for developing the electrostatic latent image.

Recording apparatus

A recording apparatus according to the present invention in which a data is recorded by charging a driven recording medium, scanning laser beams on the driven recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the driven recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode. And, the driver for driving the recording medium is controlled so as to continuously drive the recording medium when the first print mode is switched to the second print mode by the switching device. The image forming device comprises device for forming an electrostatic latent image on the recording medium by scanning laser beams in accordance with the recording data and device for developing the electrostatic latent image.

In a developing apparatus, a toner stored in a vessel is supplied to a developing roller by a toner supply roller. The toner supply roller is disposed between the vessel and roller and is partitioned from vessel by a partition plate. A elastic member of the toner supply roller is brought into contact with the inner surface of the partition plate, thereby charging the toner transferred by the elastic member by friction.

Developing apparatus having one-component developing agent

A recording apparatus according to the present invention in which a data is recorded by charging a drived recording medium, scanning laser beams on the drived recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the drived recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode. And, the driver for driving the recording medium is controlled so as to continuously drive the recording medium when the first print mode is switched to the second print mode by the switching device. The image forming device comprises device for forming an electrostatic latent image on the recording medium by scanning laser beams in accordance with the recording data and device for developing the electrostatic latent image.

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Yokohama, Japan

Naruhito Yoshida