Method of and apparatus for making heat-sensitive stencil and heat-sensitive stencil material

• US 20020018874A1
• Filed: 05/17/2001
• Published: 02/14/2002
• Est. Priority Date: 05/17/2000
• Status: Active Grant

• Current Assignee: RISO Kagaku Corporation
• Original Assignee: RISO Kagaku Corporation
• Inventors: Nakamura, Jun, Ohshima, Kenji
• Granted Patent: US 6,629,495 B2
• Time in Patent Office: Days
• US Class Current: 428/138
• CPC Class Codes: B32B 2038/047 Perforating
• CPC Class Codes: B32B 2305/026 Porous
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 27/00 Layered products comprising a layer of synthetic resin fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18
• CPC Class Codes: B32B 27/10 of paper or cardboard
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 3/266 characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• CPC Class Codes: B41C 1/144 by perforation using a thermal head
• CPC Class Codes: B41N 1/241 characterised by the adhesive means
• CPC Class Codes: B41N 1/243 characterised by the ink pervious sheet, e.g. yoshino paper
• CPC Class Codes: B41N 1/245 characterised by the thermo-perforable polymeric film heat absorbing means or release coating therefor
• CPC Class Codes: Y10T 428/24273 including aperture
• CPC Class Codes: Y10T 428/24331 including nonapertured component

Abstract

When thermally perforating a thermoplastic resin film of heat-sensitive stencil material by the use of a thermal head, supply of energy to the thermal head is cut at a time the diameter of the perforations becomes not smaller than 65% and not larger than 95% of a target diameter of the perforations.

Claims

1. A method of making a stencil by thermally forming perforations arranged in both a main scanning direction and a sub-scanning direction in a thermoplastic resin film of heat-sensitive stencil material by the use of a heat source which is heated through supply of energy, wherein the improvement comprises that

supply of energy to the heat source is cut at a time the diameter of the perforations becomes not smaller than 65% and not larger than 95% of a target diameter of the perforations.

2. A method as defined in claim 1 in which the target diameters of the perforations in the main scanning direction and the sub-scanning direction are set not smaller than 45% and not larger than 80% of the scanning pitches in the respective directions.

3. A method as defined in claim 1 in which the target area of the perforations is set not smaller than 20% and not larger than 50% of the product of the scanning pitches in the main scanning direction and in the sub-scanning direction.

4. A method of making a stencil by thermally forming perforations arranged in both a main scanning direction and a sub-scanning direction in a thermoplastic resin film of heat-sensitive stencil material by the use of a heat source which is heated through supply of energy, wherein the improvement comprises that

supply of energy to the heat source is cut at a time the area of the perforations becomes not smaller than 42% and not larger than 90% of a target area of the perforations.

5. A method as defined in claim 4 in which the target area of the perforations is set not smaller than 20% and not larger than 50% of the product of the scanning pitches in the main scanning direction and in the sub-scanning direction.

6. A method as defined in claim 4 in which the target diameters of the perforations in the main scanning direction and the sub-scanning direction are set not smaller than 45% and not larger than 80% of the scanning pitches in the respective directions.

7. An apparatus for making a stencil comprising a heat source which is heated through supply of energy, a heat source control means which supplies energy to the heat source and a scanning means which scans a thermoplastic resin film of heat-sensitive stencil material with the heat source to thermally form perforations arranged in both a main scanning direction and a sub-scanning direction in the thermoplastic resin film, wherein the improvement comprises that

the heat source control means cuts supply of energy to the heat source at a time the diameter of the perforations becomes not smaller than 65% and not larger than 95% of a target diameter of the perforations.

8. An apparatus as defined in claim 7 in which the heat source control means sets the target diameters of the perforations in the main scanning direction and the sub-scanning direction to be not smaller than 45% and not larger than 80% of the scanning pitches in the respective directions.

9. An apparatus as defined in claim 7 in which the heat source control means sets the target area of the perforations to be not smaller than 20% and not larger than 50% of the product of the scanning pitches in the main scanning and sub-scanning directions.

10. An apparatus for making a stencil comprising a heat source which is heated through supply of energy, a heat source control means which supplies energy to the heat source and a scanning means which scans a thermoplastic resin film of heat-sensitive stencil material with the heat source to thermally form perforations arranged in both a main scanning direction and a sub-scanning direction in the thermoplastic resin film, wherein the improvement comprises that

the heat source control means cuts supply of energy to the heat source at a time the area of the perforations becomes not smaller than 42% and not larger than 90% of a target area of the perforations.

11. An apparatus as defined in claim 10 in which the heat source control means sets the target area of the perforations to be not smaller than 20% and not larger than 50% of the product of the scanning pitches in the main scanning and sub-scanning directions.

12. An apparatus as defined in claim 10 in which the heat source control means sets the target diameters of the perforations in the main scanning direction and the sub-scanning direction to be not smaller than 45% and not larger than 80% of the scanning pitches in the respective directions.

16. A heat-sensitive stencil material as defined in claim 15 in which the porous support sheet is of paper made of synthetic fiber blended with natural fiber.

17. A heat-sensitive stencil material as defined in claim 15 in which the porous support sheet and the thermoplastic resin film are laminated by adhesive.

19. A heat-sensitive stencil material as defined in claim 18 in which the porous support sheet is of paper made of synthetic fiber blended with natural fiber.

20. A heat-sensitive stencil material as defined in claim 18 in which the porous support sheet and the thermoplastic resin film are laminated by adhesive.

13. A thermoplastic resin film for stencil material which is scanned by a heat source, which is heated through supply of energy, in both a main scanning direction and a sub-scanning direction and is thermally formed with perforations arranged in the main scanning and sub-scanning directions in the thermoplastic resin film, wherein the improvement comprises that

the heat shrinkable properties of the thermoplastic resin film are such that the diameter of the perforations is enlarged after cutting supply of energy to the heat source to from 105% to 154% of that at the time the supply of energy to the heat source is cut.

14. A thermoplastic resin film for stencil material which is scanned by a heat source, which is heated through supply of energy, in both a main scanning direction and a sub-scanning direction and is thermally formed with perforations arranged in the main scanning and sub-scanning directions in the thermoplastic resin film, wherein the improvement comprises that

the heat shrinkable properties of the thermoplastic resin film are such that the area of the perforations is enlarged after cutting supply of energy to the heat source to from 110% to 237% of that at the time the supply of energy to the heat source is cut.

15. A heat-sensitive stencil material which comprises a thermoplastic resin film and a porous support sheet laminated together and is scanned by a heat source, which is heated through supply of energy, in both a main scanning direction and a sub-scanning direction to be thermally formed with perforations arranged in the main scanning and sub-scanning directions, wherein the improvement comprises that

the heat shrinkable properties of the stencil material are such that the diameter of the perforations is enlarged after cutting supply of energy to the heat source to from 105% to 154% of that at the time the supply of energy to the heat source is cut.

18. A heat-sensitive stencil material which comprises a thermoplastic resin film and a porous support sheet laminated together and is scanned by a heat source, which is heated through supply of energy, in both a main scanning direction and a sub-scanning direction to be thermally formed with perforations arranged in the main scanning and sub-scanning directions, wherein the improvement comprises that

the heat shrinkable properties of the stencil material are such that the area of the perforations is enlarged after cutting supply of energy to the heat source to from 110% to 237% of that at the time the supply of energy to the heat source is cut.