Sharp Kabushiki Kaisha Corporation

Masaki Matsushita

Hirokazu Nakamura

Hisashi Yoshimura

Naozumi Ueno

Hiroshi Ishii

Takashi Goto

Takashi Gotoh

Tomomi Tanaka

Hirotsugu Matoba

Hirokazu Fujita

Shigeaki Kakiwaki

Haruhiko Deguchi

Akio Matsumoto

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

An organic insulating coating formed on a substrate is composed of two layers of a first parylene coating and a second parylene coating. Heat treatment is performed to at least the first parylene coating after being formed, at a temperature below 125&#xb0; C. for two hours. Then the second parylene coating is formed on the first parylene coating. Occurrence of pinholes is thus prevented at least in one of the two layers of the organic coatings, with the result that insulating properties of the coatings are improved.

Method for producing organic insulating coating and ink-jet printhead produced according to the method

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.

Growing community of inventors

Ikoma-gun, Japan

Masaki Matsushita