Sharp Kabushiki Kaisha Corporation

Nippon Telegraph and Telephone Public Corporation

Hisashi Yoshimura

Norihiro Ochi

Kohji Tsurui

Hirokazu Nakamura

Hajime Horinaka

Masaki Matsushita

Naozumi Ueno

Kazuya Koyama

Hiroshi Ishii

Hiroshi Onda

Masaharu Kimura

Takashi Goto

Hiroshi Kubota

Yoshio Kanayama

Takashi Gotoh

Tomomi Tanaka

Yuhi Akagawa

Hirokazu Fujita

Kouzou Yamaguchi

Kouichi Irihara

Fusao Iwagami

Yoshinobu Umetani

Shigenori Morimoto

Yoshinobu Okumura

Michihiro Yamashita

Kiyoshi Sugiyama

Akio Matsumoto

Masaharu Matsuba

Kouichi Fukushima

Takayuki Higashio

Hiromitsu Nakagawa

An ink cartridge includes an ink containing section including an ink absorbing body made of a porous material for retaining ink. The ink cartridge satisfies 200&#x2266;N&#xb7;R&#x2266;320, where N is the cell density, expressed in the number of pores per inch, of the ink absorbing body before the ink absorbing body is contained in the ink containing section; and R is a compressibility, which is a volume ratio of the ink absorbing body when the ink absorbing body is contained in a compressed state in the ink containing section to the ink absorbing body before the ink absorbing body is contained in the ink containing section. With this configuration, it is possible to (1) preventing ink leakage that is caused when the ink cartridge is inserted or detached, (2) realize stable supply of the ink when continuous ejection is performed, and (3) achieve effective utilization of the ink cartridge volume, thereby realizing an ink cartridge and an image forming apparatus which provide design indices for the ink absorbing body in accordance with properties of the ink.

Ink cartridge and image forming apparatus

An image forming apparatus in which ink depletion detection accuracy will not be deteriorated even if an air bubble is created in an ink supplying path. The image forming apparatus is provided with (a) an ink storage section for storing ink therein, (b) an ink supplying path for supplying, to a print head, the ink stored in the ink storage section, and (c) an electrode for detecting whether the ink is present or absent in the ink supplying path, an amount of the ink supplied into the ink supplying path being 1.0 cc or less per minute.

Image forming apparatus

A fixing device of the present invention includes a pressure roller and a peeling roller both of which press a heat roller. The pressure roller is disposed upstream to the peeling roller in a transport direction of a recording paper. An outer diameter of the heat roller, an outer diameter of the pressure roller, and an outer diameter of the peeling roller decrease in this order. With this arrangement, it is possible to realize a fixing device which achieves a reduced size and reduced power requirements, while ensuring a fixing property and a peeling property with respect to a recording medium. Further, with an arrangement in which the pressure roller and the peeling roller which press the heat roller are disposed so that, in a cross section orthogonal to central axes of the heat roller, the pressure roller, and the peeling roller, a first orthogonal line being orthogonal to a first line that connects a center of the heat roller and a center of the pressure roller and passing through a nip portion between both of the rollers, comes into contact with a contact area in a predetermined area on a peripheral surface of the peeling roller, a fixing device of the present invention can transport the recording paper without causing a paper jam when plural pieces of recording paper stacked are transported.

Fixing device for fixing an unfixed developing agent on a recording medium and image forming apparatus including the same

An image forming apparatus includes an ink tank; and an ink supplying path for supplying the ink from the ink tank to a print head, wherein the ink supplying path therein includes a filter, which generates negative pressure when the ink is supplied, the negative pressure being smaller than ink absorbing pressure of a nozzle of the print head. Further, the ink tank therein includes, for example, a porous ink absorbing body for retaining ink. The image forming apparatus satisfies:'&#x3c;1/() where F(m) expresses a filtration accuracy of the filter; N (cells/m) expresses a cell density of the ink absorbing body before the ink absorbing body is contained in the ink tank; and R expresses a compressibility, which is a volume ratio of the ink absorbing body when the ink absorbing body is contained in a compressed state in the ink tank to the ink absorbing body before the ink absorbing body is contained in the ink tank, on condition that: F&#x2032;=F when an opening of the filter is circle; F&#x2032;=&#x221a;{square root over ( )}2&#xb7;F in other cases.

The present invention can reduce the amount of ink in an outlet-side space which is sucked together with gas, without making the thickness of an isolating member for separating the inside of the sub-tank into an inlet-side space and the outlet-side space in the horizontal direction extremely thin nor making an inflow channel for allowing the ink in the inlet-side space to flow into the outlet-side space extremely small. The present invention has an isolating member in the form of a plate for separating the inside of a sub-tank coupled to a recording head into an inlet-side space connected to a main-tank and an outlet-side space connected to the recording head, and an inflow channel in the form of a slit for increasing the ink level in the inlet-side space while allowing the ink in the inlet-side space to flow into the outlet-side space from the isolating member.

Recording apparatus

The invention offers an inkjet printer which does not produce defective prints when bubbles enter ink supply tube. There is provided an air trap in an ink supply tube near an ink delivery port of an ink tank. The air trap is a hollow rectangular parallelepiped with a flow passage length of Lx, a height of Lh as measured from the bottom of an ink flow to a highest part, and a width of W. On its downstream end, the air trap has an outlet having a height of Ly as measured from the bottom of an ink flow. The air trap has a bubble catching space above the outlet. The dimensions are determined so that bubbles float at least up to height Ly while passing through the flow passage of length Lx. When bubbles flow into the air trap, they float and are caught in the space of the air trap before reaching the outlet.

Inkjet printer

Ink absorption pads are associated with waste ink storage apparatus in ink jet printers. Waste ink is emitted from the tubes. The waste ink is absorbed by the pads.

Inkjet printer waste ink storage apparatus

A method of fabricating a recording head is disclosed in which a needle-type control electrode is formed integrally with the substrate. The method includes steps of forming on a substrate a first member layer having a pattern such that the substrate is partially exposed. Forming a second member layer spanning a portion of the exposed substrate and a portion of the first member layer. Then, a needle-type member is formed from the second member layer. Finally, the basic portion of the recording head is completed just by joining the substrate and an overhead plate. Thus, there is no need to join the needle-like control electrode with the substrate. There is no need to position members having critical dimensions with each other.

Method of fabricating a recording head of electrostatic attraction type image recording apparatus

An ink jet print head by which ink droplet ejected from all orifices are adapted to have uniform size has the following structure. Each of a plurality of ink chambers divided by partitions is communicated with a common pressure chamber with a first filter interposed. Common pressure chamber is communicated with a common ink feed path with a second filter interposed. Common pressure chamber and each of the ink chambers are covered by a pressure chamber ceiling. On pressure chamber ceiling, a piezo vibrator is provided at a position corresponding to common pressure chamber. A movable wall which is bent and deformed to the side increasing the volume is provided corresponding to each partition. By driving a piezo vibrator, a pressure wave is generated in common pressure chamber, which wave is transmitted to each ink chamber through the first filter. When movable wall is bent and deformed, the pressure wave is absorbed, so that an ink droplet is not ejected. When movable wall is not deformed, ink droplet is ejected because of the pressure wave.

Ink jet printerhead with a plurality of nozzles and two distinct groups of filters

An ink jet head includes an ink supply path, a pressure chamber, an orifice and an oscillator. By bending a portion of the wall surface of the pressure chamber by oscillation of oscillator, ink is emitted. A portion of the wall surface of pressure chamber is formed by an oscillating plate of resin, and a unimorph including an elastic plate and oscillator provided on oscillating plate. Sidewalls separating the inside of pressure chamber are provided, and the dimension between the sidewalls is made shorter than the dimension of the unimorph.

Ink jet head allowing highly dense arrangement of nozzles

In a method of adjusting record displacement of a serial printer including a recording head which records a plurality of lines at a time in the main scanning direction, a first test pattern which is formed of a plurality of line patterns spaced apart by a prescribed distance is recorded in the main scanning direction, the record sheet is fed by a prescribed amount, and a second test pattern which is formed of prescribed recording patterns is recorded. Based on the positional relations between the first and second test patterns, the feeding amount of the record sheet is adjusted. Since the feeding amount of the record sheet is adjusted based on the positional relations between the first and second test patterns, record displacement in the feeding direction of the record sheet can be adjusted easily, and the cost increase of the serial printer can be suppressed.

Serial printer adjusting record displacement caused by transport of record sheet, and adjustment method thereof

Various ink heads with holes different in diameter can be attached to a carriage of an inkjet printing apparatus. A CPU detects the type of an ink head attached, by states of signals on signal lines. The CPU executes a printing operation in a resolution corresponding to an amount of ink discharge based on a result of detection. When one of various ink heads having a plurality of holes and having the same pitch between the holes as that of one another ink head is attached, the printing operation is carried out such that the amount of ink discharge is substantially the same for the respective ink heads, in particular, that a relation of recording paper feed amount X&equals;(C/(P,/P&minus;1)&times;P,&plus;P,is satisfied, further in particularly, C/(P,/P,)&equals;a positive number. Ink heads provided with a plurality of holes arranged with the same interval may also be attached. Thus, various ink heads can be attached to the carriage to provide a plurality of resolutions and high quality prints.

Inkjet printing apparatus

A recording apparatus capable of printing with high resolution and high precision at high speed while preventing drying of the ink jet head includes an ink jet head for emitting a plurality of types of inks one by one while performing reciprocating operation, an ink receiving equipment provided outside a recording area for receiving the inks emitted from the ink jet head, an ink emission amount setting unit for each ink, for setting the amount of emission of the ink emitted to the ink receiving equipment, and a control unit for controlling the ink jet head such that the ink of the emission amount is periodically emitted to the ink receiving equipment.

Recording apparatus for periodically emitting recording materials by material specific emission amount

In a container, an ink exhausting detecting liquid permeable sponge and an ink permeable sponge are disposed with an isolation film therebetween. The ink exhaustion detecting liquid is oil based, and has a resistance value higher than that of ink, and a specific gravity smaller than that of ink. In usage, the isolation film is drawn out of the container, whereby the ink exhaustion detecting liquid permeable sponge is brought into contact with the ink permeable sponge.

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Nara, Japan

Hisashi Yoshimura