Sharp Kabushiki Kaisha Corporation

Kenji Tani

Kazuya Masuda

Koji Tsukamoto

Shirou Wakahara

Takashi Hayakawa

Takasumi Wada

Hirohito Morioka

Yoshikazu Kondoh

Sohichi Yoshimura

Kouichi Eto

Yoshinori Nakahira

Takahiro Kawakami

Mariko Arai

Kimiko Watanabe

Masaaki Kawakami

Yasuichi Onose

Toshinori Tsujii

Takashi Ide

Hiroki Eto

Takashi Sugitoh

Katsumi Adachi

Yukihito Nishio

Nobuhiko Nakano

Kouichi Irihara

Suehiro Ueda

Hajime Yoshinaga

Yuusuke Nagano

An object of the invention is to provide a display device of an image forming apparatus capable of displaying information that the user wants to obtain in a visually easy-to-recognize manner. In a compound image forming apparatus provided with: one of original reading means for reading image information from an original, image receiving means for receiving image information from a terminal connected to a network and a line image receiving means for receiving image information from a telephone line; image forming means for forming an image based on the image information obtained by the means; and a display portion for displaying the condition of the apparatus, a display condition control portion is provided that changes the display condition of the display portion to a visually easy-to-recognize condition when the condition of the compound image forming apparatus is changed.

Image forming apparatus

An object of the invention is to provide a display device of an image forming apparatus capable of displaying information that the user wants to obtain in a visually easy-to-recognize manner. In a complex image forming apparatus provided with: one of original reading means for reading image information from an original, image receiving means for receiving image information from a terminal connected to a network and a line image receiving means for receiving image information from a telephone line; image forming means for forming an image based on the image information obtained by the means; and a display portion for displaying the condition of the apparatus, a display condition control portion is provided that changes the display condition of the display portion to a visually easy-to-recognize condition when the condition of the complex image forming apparatus is changed.

An object of the present invention is to provide an image forming apparatus for forming images which are always and stably high quality regardless of changes of ambient conditions. In the image forming apparatus, a counter electrode is disposed facing a toner holder for holding at least one color toner, to generate a potential difference between the toner holder and the counter electrode by use of various types of power supplies. Between the toner holder and the counter electrode, a counter electrode is interposed, which is provided with a plurality of gates disposed on an insulating substrate and electrode groups respectively disposed around the plurality of gates. According to the potential difference between the toner holder and the counter electrode, it is controlled whether or not the toner is caused to pass through the gates. In the image forming apparatus, a resistance value of a cleaning member is detected for removing the toner stuck on the control electrode. On the basis of the detected resistance value, ambient conditions are determined. On the basis of the conditions, a state of at least one of elements in the image forming apparatus is controlled.

An object of the present invention is to provide an image forming apparatus for enabling toner to easily pass through gates of control electrode and increasing the scattering efficiency of the toner to improve the printing quality. Since a sticking force between the toner and toner holder or among particles thereof is weakened and the toner is held on the toner holder with a slight binding force between the toner holder and the control electrode, a voltage applied for enabling the toner to pass through the gates of the control electrode and scatter toward the counter electrode can be minimized as long as the toner can pass through the gates of the control electrode. In other words, a pulse is applied to a shielded electrode just before the toner held on the toner holder passes through the gates of the control electrode, so that the sticking force between the toner and the toner holder or among particles thereof can be weakened, or the toner can be transformed into cloud-like particles. Accordingly, the toner can easily pass through the gates of the control electrode and the scattering efficiency of the toner is increased to improve the printing quality.

In a digital printer as an image forming device, a high voltage is applied to a counter electrode exclusively when the counter electrode is covered with a sheet of paper having a good insulating property, so that a strong electric field necessary for image formation is generated between the counter electrode and a toner carrier. When the counter electrode is not covered with a sheet of paper, a high voltage relay provided between the counter electrode and a high voltage power source is turned OFF so that the application of the high voltage to the counter electrode is suspended, so that the strong electric field is not generated. By doing so, it is possible to surely avoid discharge which tends to occur between the counter electrode and the toner carrier or between the counter electrode and the control electrode.

Image forming device forming an image on a recording medium using flying

A reference voltage generating circuit generates +5 V and +24 V as the reference voltages, based on the voltage from the commercial power supply, i.e., AC 100 V. This reference voltage generating circuit supplies +5 V and +24 V to various operating circuits. The reference voltage of the +5 V system is supplied to a logic circuit portion and a voltage applying device. The reference voltage of the +24 V system is supplied to a control electrode voltage source for generating the voltage to be applied to the control electrode, a fixing lamp operating portion for generating the voltage to activate heater as a part of the fixing unit, and a motor operating portion for driving motors for driving various driving devices.

Apparatus for electrostatically forming images using time stable

An image forming apparatus has a toner carrier roller, a back electrode which is located so as to face the toner carrier roller, a voltage source for applying a voltage which generates an electric field for making toner fly from the toner carrier roller to the back electrode, a control electrode which has many openings through which the toner is allowed to pass and first and second conductive layers formed around the openings and is formed so that at least portions of the first and second conductive layers which surround the openings do not overlap each other in a direction where the toner flies from the toner carrier roller to the back electrode, and a voltage source for applying a voltage which controls the toner passing through the opening according to an image signal. As a result, an electrostatic capacity is hardly formed between the first conductive layer and the second conductive layer, thereby suppressing a fall in response characteristic to the toner flying control due to the electrostatic capacity.

A charging member comprised of a conductive shaft and conductive fibers planted thereon is brought into contact with a charged member with a photoconductor provided on the surface thereof. The conductive shaft is applied with a combined voltage of d.c. voltage and a.c. voltage having a peak-peak value lower than two times the discharge starting threshold voltage that is determined by the surrounding atmosphere around the charged member. While the charging member and the charged member rotate at different surface velocity, the charged member is charged through the contact area in which impedance is low due to the influence of a.c. voltage, so that a stable surface potential close to the d.c. voltage may be charged onto the charged member. Further, it is effective that the frequency f of the a.c. voltage will be so set up as to suffice a relation: f&gt;Vp/2R, where f is a frequency of the applied a.c. voltage, Vp(mm/s) is a moving velocity of the charged member, and R(mm) is a particle size of a developer used. Moreover, it is effective that another charging member is provided on the downstream side of the aforementioned charging member.

Method of charging a built-in electrophotographic charge member

The invention is directed to an apparatus for an electrophotographic process, equipped with a charging device of a contact type using a conductive roller or brush, and the charging device used therefor. The apparatus is characterized in the following constructions: roll-shaped fiber aggregation that is rotated in contact with the photoconductive surface through a spacing member; use as applied voltage to the fiber aggregation of periodically oscillating voltage having a lower limit exceeding the surface potential of the photoconductor in the aforementioned device; a brush-type charger that is vibrated while contacted with the photoconductor surface and regulated as required; a fiber roll-type charger wherein ventilation holes are disposed on the roller substrate surface; the fiber roll-type charger with holes further including a closed container with exhausting means enclosing the charger; set-up of a product of planting fiber intervals on a fiber roller and a peripheral velocity ratio of the photoconductor to the roller such that the product is smaller the average particle size of the developer used; changing application voltage to a charger roller depending transfer-treated portion or portions otherwise on the photoconductor surface; and provision of dirt preventer, aligned with the longitudinal direction to the charging roller with conductive fiber, and shiftable between contact and spaced position.

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Yamatokoriyama, Japan

Kenji Tani