Ricoh Company, Ltd.

Teruyuki Ohnuma

Hajime Oyama

Yohta Sakon

Seiichi Miyakawa

Fumio Kawamura

Masafumi Ohta

Manabu Mochizuki

Kohji Suzuki

Toshihiko Takahashi

Mitsuru Hashimoto

Nobuo Mochizuki

Tomoyuki Shimada

Tetsuo Tsutsui

Yoshiyuki Kageyama

Yukio Ide

Chihaya Adachi

Yukio Tabata

Hiromi Demizu

Shogo Saito

Hazime Oyama

Kaoru Shimizu

Disclosed herein is an electroluminescent device comprising an anode and a cathode and one or plurality of organic compound layer sandwiched therebetween, at least one of the organic compound layers being composed of an organic compound represented by the general formula (I): ##STR1## (wherein A.sup.1 and A.sup.2 each represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group which may be identical or different with each other, Ar represents a substituted or unsubstituted pyrenyl group and n represents 1 or 2).

Electroluminescent device

Disclosed herein is an electroluminescent device having a luminescent layer comprising a luminescent material, which is capable of directly converting the energy of electric field applied thereto into a light energy and capable of providing a large surface-area luminescence.

Disclosed herein an electroluminescent device for converting an energy of an electric field applied directly to a light energy and capable of producing surface luminescent for a large area different from conventional incandescent lamps, fluorescent lamps or light emitting diodes.

Electroluminescent devices

A manual information input device allows the user to manually enter desired information using a readily available writing instrument such as a pencil rather than a specially designated input stylus such as a light pen or an electromagnetic pen. The manual information input device comprises a substrate supporting electrodes on one surface thereof, an input panel disposed in facing relation to the substrate and supporting electrodes in confronting relation to the electrodes on the substrate, a spacer disposed between the substrate and the flexible input panel and defining a closed space therebetween, and an electrically insulating material sealed in the space. The input panel is resilient. The electrodes on the substrate and the input panel jointly constitute a pixel matrix. The electrically insulating material comprises a liquid and/or a group of particles.

Manual information input device

An apparatus for developing a latent electrostatic image formed on a photoconductive recording material in a dry type electrophotographic copying machine typically employing a one-component type developer comprises a conductive electrode held in contact with the developer. The electrode is connected to a power source through a switching device and serves to charge the developer to a predetermined polarity with a predetermined potential before the latent image is developed. In this way, the latent image can be developed selectively as either a normal image or a reverse image quite easily.

Development apparatus

A reverse development is performed with application of development bias voltage to a development sleeve at the time of development, and the polarity of the bias voltage is reversed or the bias voltage is reduced to zero at the time of non-development. Furthermore, positive images and negative images can be selectively formed by changing the voltage to be applied to a charge injection electrode, without changing the bias voltage to be applied to the development sleeve.

Reverse development method

A method of and apparatus for developing a latent electrostatic image in which a one-component type developer is deposited on the surface of a developer applicator having a conductive and elastic endless surface and the developer applicator is brought into pressure contact with a latent electrostatic image bearing member having a latent electrostatic image thereon. The peripheral speed of the developer applicator is slightly greater than that of the latent electrostatic image bearing member. In the case where the developer on the surface of the developer applicator is charged by charge injection from a blade electrode which is in contact with the developer, the present development apparatus is provided with a means for insulating the opposite top end portions of the blade electrode from the surface of said developer applicator.

Apparatus for developing electrostatic image

Charging, imaging, developing, transfer and cleaning units are operatively arranged about the circumference of a rotary photoconductive drum, the developing unit comprising a magnetic brush. A discharge unit is disposed between the transfer unit and the cleaning unit and comprises a light source and a corona discharge element to simultaneously illuminate the drum causing photoconduction and expose the drum to an electric field thereby neutralizing any residual charge on the drum and residual toner particles remaining on the drum after the transfer operation. The residual toner is subsequently removed by the magnetic brush of the developing unit.

Drum cleaning process and apparatus for electrophotography

A development apparatus for developing a latent electrostatic image formed on a photoconductor with a one-component type developer has a charging device comprising at least two charging members for charging the developer held in a developer container. The first charging member serves both as a doctor blade and for regulating the amount of the developer on the development roller, and the second charging member charges the developer before it is charged by the first charging member. In the second charging member, there is formed a hole for allowing the developer to pass therethrough. The developer scraped by the first charging member is returned to the developer container through the hole and part of the scraped developer is carried back to the first charging member, so that a developer circulation path is formed in the charging device. While passing through the developer circulation path, the developer is charged further, whereby the developer is sufficiently charged before it is actually used for development.

One or more rows of focussing optical fibers are disposed between an original document carrier and a photoconductive member. An illumination lamp illuminates an original document on the carrier and the fibers focus an image of a linear portion of the document onto the photoconductive member. Relative movement between the document carrier, fibers and photoconductive member perpendicular to the row or rows of fibers is produced to scan the document. An aperture assembly is provided between the fibers and the photoconductive member difining an aperture wide enough that unevenness of the intensity of the image on the photoconductive member due to the individual fibers is eliminated. The intensity of the light image is controlled by utilization of a variable transformer or triac provided to the illumination lamp.

Electrophotographic apparatus comprising improved imaging system

A magnetic developing process for use in electrophotographic or electrostatic recording techniques employs a magnetic brush formed by a developer which comprises a powder mixture of a low resistance toner and a high resistance toner, at least one of which comprises a magnetic toner. Both toners are triboelectrically charged, and the magnetic toner serves as a carrier, so that both toners are attracted to an electrostatic image to provide a developing thereof.

Magnetic brush developing process for electrostatic images

A development apparatus for use with dry type copying apparatus having: a development roller, which is rotated in close proximity to a latent electrostatic image bearing recording material; a hopper for supplying an insulating toner onto the development roller; and a single developer regulating member in the form of a blade having an acute angle tip disposed at the edge of or right behind the outlet of the hopper in such manner that the top surface of the member forms an acute angle with the downstream side in the direction of development roller rotation of a tangent to the development roller at a point right under the tip of the development regulating member. Alternatively a single or a plurality of triboelectric charging members may be disposed at the edge of or right behind the outlet of the hopper of the respective angles with the top surfaces of the blades with respect to the respective tangents to the points on the surface of the development roller right under the respective tips varying from an acute angle to an obtuse angle in the direction of development roller rotation.

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Yokohama, Japan

Teruyuki Ohnuma