Riso Kagaku Corporation

Nippon Seimitsu Kogyo Kabushiki Kaisha

Asahi-Dow Limited

Takanori Hasegawa

Takanobu Shimada

Akira Yasuda

Hideo Negishi

Noboru Inamine

Susumu Oshio

Shoichi Ikejima

Eiji Nakazawa

Junji Takahashi

Takashi Kanda

Junnosuke Katsuyama

Hiroshi Saito

Toshihiko Hirose

Nobuyuki Abe

Masakazu Kera

Masaki Oshima

Shuntaro Yoshida

Takao Sato

Yoshikazu Hara

Ryuji Higa

Noboru Hayama

Kazuo Nakano

Koichi Okusawa

Kouichi Uchiyama

Hideo Shoji

Toru Hibara

Yoshio Tsuji

Takahiro Furuyama

Shoji Nonoyama

Kiyoshi Takehara

Shinichi Shimoyama

A device for obliterating printed information on a sheet utilizes an information concealing printing unit for printing an information concealing pattern over a surface of a sheet carrying printed information. On printing the information concealing pattern over the surface of the sheet carrying the printed information, the printed information becomes unreadable. Various types of printing devices may be used and the printed information which is obliterated may be first recorded in electronic format for later retrieval.

Sheet printd information obliterating device

Provided is a method and device for stencil printing which can readily achieve a stencil printing of a prescribed even density even when the surface area of the printing surface is great, and which can ensure a multi color printing to be made without mixing of colors even when a large number of copies are to be printed. Printing ink having a sufficient consistency to retain its shape is deposited on a stencil master plate S as ink lumps B, and a stencil master plate S is placed in a pressure chamber 17 with its surface carrying the ink lumps B facing the diaphragm 15, the pressure chamber 17 having a wall portion formed by a diaphragm 15 which is at least either flexible or elastic. The pressure chamber 17 is then depressurized so that the diaphragm 15 conforms to the ink lumps B and wraps itself onto the ink lumps B, and the stencil master plate S in turn comes into close contact with the printing paper P by being pressed by the diaphragm 15 to thereby achieve a stencil printing on a sheet of printing paper through pressurization of the ink lumps B on the stencil master plate S.

Method and device for pressure type stencil printing

Provided is a flash bulb type thermal copying device which allows divided exposure to be carried out in a simple but highly efficient manner. The thermal copying device comprises an exposure unit 10 having a light radiating window 22, and a flash light source 24 for radiating flash light upon the light radiating window 22, a planar holder 50, detachably mounted on the exposure unit 10, carrying an assembly of an original and a heat sensitive recording medium placed one over the other in an intimate thermal contact, and moveable across the light radiating window 22 with a light transmitting region provided on one side thereof aligned with the light radiating window 22, and a feed drive device 30 and 86 for moving the holder 50 and the exposure unit 10 relative to each other across the light radiating window 22. The holder can also be used as a stencil printing device to increases its acceptability for home use.

Flash bulb type thermal copying device

Provided is a device which can form favorable perforated images corresponding to the resolution of the thermal head, reproduce faithful printed images for all kinds of original picture images, avoid ink transfer, and adapt itself to different environmental conditions, and is suitable for use with different thermal recording materials such as thermal recording paper, OHP TP sheets, and thermal stencil master plates. In the device of the present invention, a thermal head 4 consisting of a plurality of heat emitting elements 5 arranged in a single row in the primary scanning direction is directly contacted to the recording surface of a thermal recording material such as thermal recording paper, and the thermal recording material 1 is moved relative to the thermal head 4 in the secondary scanning direction which is perpendicular to the direction of the row of the heat emitting elements so that picture images may be formed with a dot matrix by selectively heating the thermal heat emitting elements at an appropriate timing in relation to the movement of the thermal recording material in the secondary scanning direction, the ratios of the length of each heat emitting element 5 in the primary and secondary scanning directions to the pitches of the primary and secondary scanning are set 30 to 70% and 60 to 95%, respectively.

Device and method for dot-matrix thermal recording

A master plate making printing device for stencil printing on a print object is disclosed. The master plate making printing device comprises a stencil master plate holding member. The device also includes a plate making device for making a plurality of stencil master plates in different locations of a stencil master plate sheet supported by the stencil master plate holding member in a pre-defined mutual positional relationship. A motor is provided for causing a relative displacement between the stencil master plate sheet and the print object so as to place the print object to positions corresponding to the different stencil master plates formed in the stencil master plate sheet. Stencil printing means are provided for carrying out at a process of stencil printing on the print object by using each of the different stencil master plates formed in the stencil master plate sheet.

Master plate making printing device

To allow data to be exchanged between a printing drum and a stencil printing device main body in a highly adaptable manner with regard to the increase in the kinds of data to be transmitted without requiring any change in mechanical structures, light emitting devices 43, 65 and light receiving devices 45, 63 are arranged in mutually opposing parts of the printing drum 7 and the main body frame 1 to allow optical communication between them. Other modes of wireless communication may be used in place of the optical communication. This invention is particularly useful when the printing drum 7 is detachably mounted on a main body frame 1 of the stencil printing device, and the main control unit is required to adapt itself to different printing drums.

Rotary stencil printing drum equipped with a wireless data communication

A motor-type ink sensor for detecting ink in a printing device of a printing apparatus is formed of an agitating part disposed in a position of an ink fountain formed in the printing device, a motor for driving to rotate the agitating part, and a control section for detecting ink from the driving condition of the motor.

Motor-type ink sensor

To positively compress ejected master plates at a high compression ratio without requiting any complex structure, a piston member for compressing ejected master plates is placed in an ejected master plate box for receiving ejected master plates from an ejected master plate receiving inlet so as to be moveable between a first position and a second position, and the movement of the piston member toward the second position causes the stencil master plates to be compressed against an end wall of the ejected master plate box. The piston member is provided with a motor-driven suction fan which draws air out of the ejected master plate box to move the piston member toward the second position, and is biased toward the first position by a spring member.

Ejected master plate processing device for a stencil printing device

In a stencil printing device, a plurality of printing drums are mounted on a turret-like printing drum supporting member, and the indexing rotary movement of the printing drum supporting member and the rotary actuation of each of the printing drums thereon are effected by a common motor without regard to the number of the printing drums so that the overall structure can be simplified, and the control of the indexing rotary movement of the planetary plate disk and the rotary actuation of each of the printing drums can be accomplished in a centralized manner. The present invention is particularly useful in a stencil printing for full color printing.

Stencil printing device, and assembly for supporting a plurality of

In a master plate sheet clamping device for a rotary printer in which a moveable clamping plate is provided in the printing drum so as to be moveable between a clamping position for clamping a master plate sheet against the outer circumferential surface of the printing drum and an unclamping position for releasing the master plate sheet from the printing drum, to allow a reliable clamping and unclamping action to be carried out with a highly simple structure without requiring a large solenoid device or a mechanism for preventing the rotation of the printing drum, the printing drum carries a motor for moving the moveable clamping plate between the clamping position and the release position, and electric power is supplied to the motor via power collector members provided on the printing drum and selectively moveable power supply members provided on a fixed member of the printer.

Master plate sheet clamping device for a rotary printer

To allow a highly accurate superimposition printing to be accomplished in a simple manner without requiring any complicated positioning work, a plurality of stencil master plates A, B and C are formed in different parts of a single stencil master plate sheet S with a pre-defined positional relationship, and the printed images by the different stencil master plates A, B and C formed on the common stencil master plate sheet S are superimposed on a same region of printing paper P by causing a relative displacement between the stencil master plate sheet S and the printing paper P. The present invention is particularly suitable for achieving a color printing by superimposing stencil prints made by ink of different colors.

Stencil printing method

The present invention provides a printing drum for a rotary stencil printing device, comprising: a clamp for clamping a leading edge of a stencil master plate sheet along a line extending axially on an outer circumferential surface of the printing drum; and cutting device mounted on the printing drum for cutting the stencil master plate sheet to define a trailing edge of the stencil master plate sheet mounted on the printing drum. By thus providing the cutting device on the printing drum, the stencil master plate can be accurately cut because the cut length of the stencil master plate can be determined in relation with the circumferential length on the printing drum, and the cut edge of the stencil master plate can be made always exactly parallel to the axial line of the printing drum because there is no relative movement in the feeding direction between the stencil master plate sheet and the cutting device.

Method and apparatus for mounting a master plate on a printing drum

A printing drum is rotatable supported by a fixed hollow cylindrical member at two axially spaced positions thereof so that the printing drum may be supported in a highly stable fashion and any mis-alignment of the printing drum can be avoided. Also, the interior of the fixed hollow cylindrical member provides an easily accessible space for accommodating a printing ink container and a pump for supplying printing ink. In particular, by using a squeegee blade instead of a squeegee roller, a particularly advantage can be obtained because the diameter of the fixed hollow cylindrical member can be such that an annular chamber defined between the fixed hollow cylindrical member and the inner circumferential surface of the printing drum is barely sufficient to accommodate the squeegee blade in the annular chamber, and the fixed hollow cylindrical member can provide a highly rigid support structure.

Printing drum assembly for a stencil printing device

The stencil printing device of the present invention comprises a mixing unit for receiving the first liquid from the first liquid storage container and the second liquid from the second liquid storage container, and producing printing ink by mixing the two liquids, a printing ink supply passage for conducting the printing ink produced by the mixing unit to an ink squeegee unit of a printing drum, ink amount sensor for detecting the amount of the printing ink in the ink squeegee unit, and ink supply control unit for controlling the amount of the printing ink that is supplied from the mixing unit to the ink squeegee unit according to the amount of printing ink detected by the ink amount sensor. Thus, a relatively large number of prints can be made with each bottle of printing ink so that the frequency of replacing the ink bottle may be reduced. Additionally, stable stencil printing can be carried out by receiving printing ink having prescribed consistency and other desirable properties irrespective of the age of the printing ink or the surrounding temperature without requiring any human intervention.

Stencil printing device having an ink mixing unit

To the end of allowing an image makeup process to be easily and efficiently carried out even when different image makeup functions are to be applied to different regions of a single original image without requiring a plurality of region designating sheets, a region designating sheet Sw carrying region designating images is photoelectrically read, the region designating images of the region designating sheet Sw are displayed on a display unit, region designating data for specifying the regions to which image makeup functions are to be applied is obtained through a specifying process conducted on the region designating images displayed on the display unit by using a touch panel, available image makeup functions for each of the regions specified by this specifying process are displayed on the display unit, and the image makeup functions are applied to the designated regions by obtaining image makeup function designating data through a specifying process conducted on the list of image makeup functions displayed on the display unit by using the touch panel.

Growing community of inventors

Tokyo, Japan

Takanori Hasegawa