Riso Kagaku Corporation

Hirohide Hashimoto

Masakatsu Arai

Sadanao Okuda

Kenji Oshima

Taku Naitou

Kaoru Kimura

Yukihiro Maeda

Satoru Komata

Mitsuru Takeno

Mitsuru Ujiie

Kenichi Oshio

Gen Totsuka

Yosuke Ike

A stencil printing machine has a rotatable printing drum including an outer peripheral wall of ink impermeable material. A stencil paper is mounted on the surface of the outer peripheral wall. An ink supplying mechanism includes an ink supplying unit in the outer peripheral wall of the printing drum. The ink supplying mechanism supplies ink from the ink supplying unit to the surface of the outer peripheral wall. A pressure roller presses a fed print sheet against the outer peripheral wall. An ink recovering mechanism recovers ink which has flown out of a maximum printing area of the outer peripheral wall of the printing drum. A pressing mechanism presses the stencil paper against the outer peripheral wall of the printing drum.

Stencil printing machine, ink recovering method, image unevenness preventing method, and ink adapting method

A piston-type ink container is inserted into an ink container holder of a stencil printer so that an ink suction nozzle of the stencil printer is fitted in a small diameter portion of the ink container to suck the ink in the ink container through an ink discharge port on the tip of the small diameter portion. A vacuum release mechanism at least partly releases vacuum in the space evacuated by the ink suction nozzle before the tip of the nozzle and the tip of the small diameter portion are aligned with each other when the ink container is drawn from the ink container holder.

Ink supply system and ink supply method for stencil printer and ink container

A stencil printing machine is provided as including a downstream rotary printing drum with an outer circumferential periphery mounted with a stencil sheet , and a rotary press roller which is moveable between a pressurized position to press an outer circumferential periphery of the printing drum and a separated position displaced from the outer circumferential periphery of the printing drum , wherein a print sheet , which is fed, is pressed and transferred between the printing drum and the press roller which rotate together, and, during such a pressurized transfer stage, ink is transferred to the print sheet to perform printing operation. The outer circumferential periphery of the press roller is formed with micro-convexities and concavities.

Stencil printing machine

A stencil printing ink container comprises a cylinder, an area of one end of the cylinder, which area is other than an ink discharge opening section, being closed with an end wall, the other end of the cylinder being open, and a piston, which undergoes a sliding movement in an axial direction of the cylinder and along its inner circumferential surface. The ink container is filled with ink having a viscosity of at most 7.5 Pa&middot;s with respect to a shear rate of 100 sec and at 23&deg; C. and satisfies a specific relationship among an inside radius of the cylinder, an inside radius of the ink discharge opening section, a length of the ink discharge opening section, a weight of the ink filled in the ink container, a sliding movement starting load of the piston, and the viscosity of the ink.

Stencil printing ink container

A stencil printer includes a printing drum which is rotated bearing a stencil wound around the printing drum, a pair of paper feed rollers which are rotated in contact with each other to supply a printing paper to the printing drum, and a press roller which is rotated in contact with the printing drum to convey the printing paper supplied to the printing drum with the printing paper pressed against the stencil on the printing drum. A paper feed roller driver drives the paper feed rollers, and a paper feed roller controller controls the paper feed roller driver to rotate the paper feed rollers at a peripheral speed higher than that of the printing drum at least from the time the leading end of the printing paper reaches the printing drum to the time the trailing end of the printing paper passes the paper feed rollers.

Stencil printer

Provided is a heat-sensitive stencil sheet comprising an ink-impermeable thermoplastic film and a porous substrate laminated to the film, characterized in that the porous substrate is a screen gauze which is made of synthetic fibers having a fiber diameter of 25-60 .mu.m and has a mesh number of 160-190 or 210-290. The screen gauze may be subjected to calendering.

Heat sensitive stencil sheet

A stencil printing sheet is disclosed comprising a resin film and optionally a support for the resin film which is fixed to the resin film with an adhesive, wherein the resin film has a layer for preventing thermal fusion including a polyethylene wax and arranged on one surface thereof. The stencil printing sheet does not cause breakage of the resinous film during a perforating process even at a high printing speed using a thermal head, provides excellent perforation images, and exhibits a long-lasting, excellent resistance to thermal fusion.

Growing community of inventors

Ibaraki-ken, Japan

Hirohide Hashimoto