Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kasiha

Kazuya Masuda

Shirou Wakahara

Kenji Tani

Hirohito Morioka

Mariko Arai

Yoshinori Nakahira

Takashi Ide

Yoshikazu Kondoh

Sohichi Yoshimura

Kouichi Eto

Takahiro Kawakami

Yasuichi Onose

Kimiko Watanabe

Koji Tsukamoto

Masaaki Kawakami

Hajime Yoshinaga

Toshinori Tsujii

Hiroki Eto

Takashi Sugitoh

Kenji Tanaka

Kenji Nakanishi

Michiaki Nishimura

Nobuhiko Nakano

Yoshifumi Maitani

Kouji Yamaji

Noritomo Nakashima

Suehiro Ueda

Kazunori Miyamoto

Kunihiro Kobayashi

Takehiro Kato

Kohichi Sumida

Yuusuke Nagano

In the correction of the quantity of light of a light source used in an image reader which irradiates an original document with the light source, receives the reflected light by a CCD and reads the original document image, at the time of a document moving mode in which the document moves, correction of the quantity of irradiation light of the light source is performed by reading a first standard white board which extends over the whole area in the main scanning direction, prior to the initiation of readout of the moving document, and upon initiation of readout of the moving document, a second standard white board arranged outside the document passing area is read by using the same light source, with the read operation of the moving document, and correction of the quantity of irradiation light of the light source is performed based on the reflected light from the second white board.

Image reader and method for correcting the quantity of light source

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 image forming apparatus having a plurality of discharge trays is provided, from which a user can readily obtain printed sheets he has requested. The user inputs a secret code at an operating and displaying section, which secret code the user specified at the terminal device at the time of print request (S ). When a coincidence between the inputted secret code and a secret code stored in secret code storage section is judged (S ), the target discharge tray information corresponding to the secret code is read out from a secret code storage section (memory) and displayed on the operating and displaying section (S ). Accordingly, the user can visually recognize information about a discharge tray on which the user's requested printed sheets are discharged.

An image forming apparatus of the present invention includes ring electrodes for controlling flying of toner from a carrier to a sheet, and a control power source section for applying a potential that is in accordance with an image signal to each ring electrode. The control power source section carries out, in the case where the image signal is applied to each ring electrode so that the potential is applied at the same timing, a control of shifting the timing of applying ON potential so that the sum of transient current flowing through each ring electrode at a predetermined time is smaller than the sum of maximum value of the transient current flowing through each ring electrode. This ensures that the amount of transient current supplied at a predetermined time to each ring electrode by the control power source section is reduced.

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 driving circuit includes: a first semiconductor switch with its source connected to a high-voltage power source; amultiple number of diodes with their anodes commonly connected to the drain of the first semiconductor switch; a multiple number of second semiconductor switches, each being connected at the drain to the cathode of the corresponding diode and the sources being commonly connected to a low-voltage power source. In this configuration, the first semiconductor switch is turned on so that all the outputs once have the high voltage supplied and then the plural second semiconductor switches are selectively turned on so as to output the low voltage from their output terminals.

Driving circuit for a control electrode provided in an image forming

In an image forming apparatus having a control electrode including gates for allowing toner to pass through them, an image is formed by allowing or disallowing the toner to jump from the toner support to the opposing electrode whilst controlling the electric field near the control electrode elements by applying either 300 V or 0 V to the control electrode from the control electrode voltage source in accordance with image data. Virtual capacitance arising between interconnections associated with the control electrode is limited to or below a predetermined level much lower than the capacitance of the control electrode while the consumed current is maximized under the predetermined conditions.

Image forming apparatus forming an image on a recording medium using

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

A data coding system is arranged such that character font data is compressed in a unit of 4-bit in a form of a bit string with a compression width of 4-bit in the Huffman coding system. The data coding system employs a code structure in the Huffman coding system for respectively converting three bit strings selected in order from that of the highest appearance frequency in a unit of 4-bit in the character font data into the compressed codes expressed using not more than 3 bits. The described system permits a significantly improved compression rate of the character font data into respective compressed codes.

Data coding system and decoding circuit of compressed code

An apparatus according to the present invention includes a stepping motor (5) and a motor drive circuit (4) for first moving a lamp unit to hit the unit against a reference object opposite to an origin and then moving the unit toward the origin, a CPU (3) for measuring the distance through which the lamp unit is moved from the reference object toward the origin, and the CPU (3) for controlling the lamp unit so that the lamp unit stops at the origin according to the distance measured from the reference object.

Origin detector in image scanner

An image forming apparatus includes: an opposing electrode disposed facing a supporting device; a control electrode disposed between the supporting device and the opposing electrode and having a plurality of gates which form passages for the developer particles; a controlling device which generates a predetermined potential difference between the supporting device and the opposing electrode, supplies a voltage to the control electrode, and, by varying the potential applied to the control electrode, controls passage of the gates for the developer particles; and a plurality of voltage supplying device to supply voltages to the control electrode.

The control device is characterized by including a linear encoder for storing two pieces of information on two phases about a printing position in one storing part located on a longitudinal axis of the linear encoder, reading means for reading the pieces of information on two phases stored in the storing part of the linear encoder, and control circuits for controlling a printing position based on the informations on two phases read by the reading means.

Device for controlling printing position

An image signal processing apparatus is provided with an image signal generation device for sequentially generating image signals representing light and shade of an original image per every picture element. The image signal processing apparatus is also provided with an extreme portion detection device for comparing the generated image signal of an observation picture element and each of the generated image signals of a plurality of peripheral picture elements which are positioned in the vicinity of the observation picture element, and judging whether the compared observation picture element is an extreme portion or not. The image signal processing apparatus is further provided with a correction device for correcting a level of the image signal of the observation picture element, which is judged to be the extreme portion by the extreme portion detection device, by use of a calculation predetermined with respect to the level of the image signal.

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Nara, Japan

Kazuya Masuda