EP0284046B1 - Sheet feeder - Google Patents
Sheet feeder Download PDFInfo
- Publication number
- EP0284046B1 EP0284046B1 EP19880104657 EP88104657A EP0284046B1 EP 0284046 B1 EP0284046 B1 EP 0284046B1 EP 19880104657 EP19880104657 EP 19880104657 EP 88104657 A EP88104657 A EP 88104657A EP 0284046 B1 EP0284046 B1 EP 0284046B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheet
- feeding
- feeding roller
- topmost
- case
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J13/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, specially adapted for supporting or handling copy material in short lengths, e.g. sheets
- B41J13/10—Sheet holders, retainers, movable guides, or stationary guides
- B41J13/103—Sheet holders, retainers, movable guides, or stationary guides for the sheet feeding section
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H3/00—Separating articles from piles
- B65H3/02—Separating articles from piles using friction forces between articles and separator
- B65H3/06—Rollers or like rotary separators
- B65H3/0623—Rollers or like rotary separators acting at least during a part of each separation cycle on the articles in a direction opposite to the final separating direction
Definitions
- the invention relates to a sheet feeder for a printer, according to the pre-characterizing part of claim 1.
- the present invention relates to a sheet feeder for preventing undesirable plural sheet feeding.
- DE-A-2 407 098 - from which the present invention starts out - shows a sheet feeder for feeding a topmost sheet of stacked sheets being contained in a sheet case by means of a feeding roller from said sheet case into a portion of a printer, where characters or the like are printed onto said sheet.
- the feeding roller In order to have a separation of the topmost sheet from the remaining stacked sheets prior to feeding the topmost sheet from the sheet case, the feeding roller first carries out a reverse rotation, so that the topmost sheet is fed into the sheet case causing creation of a bow or curve in said topmost sheet, as the rear end of the sheet abuts against the inner rear surface of the sheet case. Said bow or curve then should separate the topmost sheet from the remaining stacked sheets, so that upon rotation of the feeding roller into feeding direction the topmost sheet is fed out of the sheet case.
- Subclaim 2 contains an advantageous modification of the invention.
- FIG.1 shows a sectional view of sheet feeder of an embodiment of the present invention.
- An ink sheet 8 is conveyed to a take-up reel 10 from a feeding reel 9.
- a feeding roller 6 is moved so as to touch a top paper 7 (or other kind of sheet) of stacked papers in a paper cartridge 5. Then, the feeding roller 6 is rotated in reverse direction for a small angle as shown in FIG.1, so that the rear end of the paper touches a sheet stopper 14 provided at the rear end of the cartridge 5. Because the end part of the paper 7 is pushed to the sheet stopper, the top sheet is bent as shown in FIG.1. Therefore, the sheets are separated, even in case of close sticking of two or more sheet papers 7.
- the feeding roller 6 rotates in the forward direction for taking out the separated top paper 7 from the paper cartridge 5.
- the paper 7, thus taken from the paper cartridge 5, is transferred to a platen roller 2. Further, the paper 7 is transferred to a position which is between the platen roller 2 and a thermal head 1 by means of pinch rollers 3, 4, and is printed with e.g. yellow ribbon. When the yellow print operation is completed, the paper 7 is transferred to a first paper passage 12.
- the paper 7 is transferred to a second paper passage 13 by reversely rotating the platen roller 2. Then, the paper 7 is printed with e.g. magenta ribbon with rotation of the platen roller 2. Than, e.g. cyan print operation is carried out in the same manner as yellow or magenta print operation.
- FIG.2 shows a sectional view of the cartridge 5.
- the paper stopper 14 is provided at the rear end of the cartridge 5.
- a member 14a having elasticity and large friction in a direct ion of its surface such as any one member of known hook and loop fastener, is provided.
- FIG.3 is a block diagram of control circuit 15.
- the control circuit 15 has a driver 22, a controller 20, an output port 38, ROM 32, CPU 34, RAM 36 and an input port 30.
- the driver 22 is provided for driving a motor 24 for rotating the feeding roller 6.
- CPU 34 detects the status of the printer by inputting status signals from the input port 30 and controls the controller 20 and the positioning circuit 3 for feeding roller 6 by outputting control signals from the output port 38.
- CPU 34 controls the printer in accordance with a computer program stored in ROM 32.
- FIG.5 shows a flow chart of this program.
- CPU 34 controls the positioning circuit 40 through the output port 38 to issue a command signal to contact the feeding roller 6 to the top sheet (step S1). Then, in step S2, CPU 34 outputs control pulses to the input terminal CU of the controller 20.
- the controller 20 outputs pulse signals as shown in FIG.4A from output terminals ⁇ 1 , ⁇ 2 , ⁇ 3 and ⁇ 4.
- the driver 22 outputs signals corresponding to the pulse signals as shown in FIG.4A for driving the stepping motor 24. Therefore, the stepping motor 24 rotates in reverse direction.
- step S3 CPU 34 outputs control pulses to the input terminal CD of the controller 20.
- the controller 20 outputs pulse signals as shown in FIG.4B from output terminals ⁇ 1 , ⁇ 2 , ⁇ 3 and ⁇ 4. Therefore, the stepping motor 24 rotates in forward direction.
- the sheet feeder is applied for a color thermal printer
- the sheet feeder is applied for mono-color thermal printers or dot-matrix printers (mechanical impact printer).
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Handling Of Cut Paper (AREA)
- Sheets, Magazines, And Separation Thereof (AREA)
- Handling Of Sheets (AREA)
Description
- The invention relates to a sheet feeder for a printer, according to the pre-characterizing part of
claim 1. In particular, the present invention relates to a sheet feeder for preventing undesirable plural sheet feeding. - DE-A-2 407 098 - from which the present invention starts out - shows a sheet feeder for feeding a topmost sheet of stacked sheets being contained in a sheet case by means of a feeding roller from said sheet case into a portion of a printer, where characters or the like are printed onto said sheet.
- In order to have a separation of the topmost sheet from the remaining stacked sheets prior to feeding the topmost sheet from the sheet case, the feeding roller first carries out a reverse rotation, so that the topmost sheet is fed into the sheet case causing creation of a bow or curve in said topmost sheet, as the rear end of the sheet abuts against the inner rear surface of the sheet case. Said bow or curve then should separate the topmost sheet from the remaining stacked sheets, so that upon rotation of the feeding roller into feeding direction the topmost sheet is fed out of the sheet case.
- However, due to the fact that the rear edge of the topmost sheet is pressed against the inner rear surface of the sheet case upon separating the topmost sheet from the sheet stack for forming the bow or curve, there is the danger that the rear edge of the topmost sheet slips over the upper rear rim of the sheet case, this leading to misalignments of the topmost sheet with respect to the feeding roller and/or no sufficient separation of the topmost sheet from the sheet stack.
- It is therefore an object of the present invention to provide a sheet feeder ensuring a reliable separation of a topmost sheet to be feeded from the sheet case from the remaining sheet stack.
- Solution of the object is achieved by the characterizing features of
claim 1. - Subclaim 2 contains an advantageous modification of the invention.
- The following is an explanation of the invention, taken in conjunction with the accompanying drawings, in which:
- FIG.1 is a sectional view of a color printer having a sheet feeder embodying the present invention;
- FIG.2 is a sectional view of the paper cartridge in FIG.1;
- FIG.3 is a circuit diagram of a control circuit of the paper cartridge of FIG.1;
- FIGs. 4A and 4B are time charts for showing an operation of the control circuit of FIG.3; and
- FIG.5 is a flow chart for showing a feeding operation of the control circuit.
- FIG.1 shows a sectional view of sheet feeder of an embodiment of the present invention. An ink sheet 8 is conveyed to a take-
up reel 10 from a feeding reel 9. Afeeding roller 6 is moved so as to touch a top paper 7 (or other kind of sheet) of stacked papers in apaper cartridge 5. Then, thefeeding roller 6 is rotated in reverse direction for a small angle as shown in FIG.1, so that the rear end of the paper touches asheet stopper 14 provided at the rear end of thecartridge 5. Because the end part of thepaper 7 is pushed to the sheet stopper, the top sheet is bent as shown in FIG.1. Therefore, the sheets are separated, even in case of close sticking of two ormore sheet papers 7. Then, thefeeding roller 6 rotates in the forward direction for taking out the separatedtop paper 7 from thepaper cartridge 5. Thepaper 7, thus taken from thepaper cartridge 5, is transferred to aplaten roller 2. Further, thepaper 7 is transferred to a position which is between theplaten roller 2 and athermal head 1 by means ofpinch rollers paper 7 is transferred to afirst paper passage 12. - Next, the
paper 7 is transferred to asecond paper passage 13 by reversely rotating theplaten roller 2. Then, thepaper 7 is printed with e.g. magenta ribbon with rotation of theplaten roller 2. Than, e.g. cyan print operation is carried out in the same manner as yellow or magenta print operation. - FIG.2 shows a sectional view of the
cartridge 5. At the rear end of thecartridge 5, thepaper stopper 14 is provided. On a face of the stopper to be touched by the paper, amember 14a having elasticity and large friction in a direct ion of its surface, such as any one member of known hook and loop fastener, is provided. - FIG.3 is a block diagram of
control circuit 15. Thecontrol circuit 15 has adriver 22, acontroller 20, anoutput port 38,ROM 32,CPU 34, RAM 36 and aninput port 30. Thedriver 22 is provided for driving amotor 24 for rotating thefeeding roller 6.CPU 34 detects the status of the printer by inputting status signals from theinput port 30 and controls thecontroller 20 and thepositioning circuit 3 forfeeding roller 6 by outputting control signals from theoutput port 38.CPU 34 controls the printer in accordance with a computer program stored inROM 32. - FIG.5 shows a flow chart of this program.
CPU 34 controls thepositioning circuit 40 through theoutput port 38 to issue a command signal to contact thefeeding roller 6 to the top sheet (step S1). Then, in step S2,CPU 34 outputs control pulses to the input terminal CU of thecontroller 20. When the control pulses are inputted to the input terminal CU of thecontroller 20, thecontroller 20 outputs pulse signals as shown in FIG.4A from output terminals ϑ₁ , ϑ₂ , ϑ₃ and ϑ₄. Thedriver 22 outputs signals corresponding to the pulse signals as shown in FIG.4A for driving thestepping motor 24. Therefore, the steppingmotor 24 rotates in reverse direction. - Next, in step S3,
CPU 34 outputs control pulses to the input terminal CD of thecontroller 20. When the control pulses are inputted to the input terminal CD of thecontroller 20, thecontroller 20 outputs pulse signals as shown in FIG.4B from output terminals ϑ₁ , ϑ₂ , ϑ₃ and ϑ₄. Therefore, the steppingmotor 24 rotates in forward direction. - Although in the embodiment of the invention the sheet feeder is applied for a color thermal printer , in other modified embodiments of the invention the sheet feeder is applied for mono-color thermal printers or dot-matrix printers (mechanical impact printer).
- Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been changed in the details of construction and the combination and arrangement of parts may be resorted to without departing from the invention as claimed.
Claims (2)
- A sheet feeder comprising:
a sheet case (5);
a sheet stopper (14);
a feeding roller (6) which, in feeding operation, touches a topmost sheet (7) of stacked sheets in said sheet case (5);
a feeding roller motor (24) for driving said feeding roller (6) and
motor driving means (22) for feeding forward rotation current to said feeding roller motor (24) for issuing said topmost sheet (7) from said sheet case (5) and a reverse rotation current to said feeding roller motor (24) for a short time prior to feeding of said forward rotation current,
characterized in that
said sheet stopper (14) is provided at the rear end of said sheet case (5) wherein a touching surface (14a) of said sheet stopper (14) is of a material having friction against the topmost sheet (7) and elasticity, wherein upon feeding of said reverse rotation current to said feeding roller motor (24) the rear end of said topmost sheet (7) touches and pushes said sheet stopper (14), thereby causing separation of said topmost sheet (7). - A sheet feeder according to claim 1, characterized in that said sheet stopper (14) is a loop-shaped member of a hook and loop fastener.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP46348/87 | 1987-03-27 | ||
JP4634887U JPS63154546U (en) | 1987-03-27 | 1987-03-27 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0284046A1 EP0284046A1 (en) | 1988-09-28 |
EP0284046B1 true EP0284046B1 (en) | 1991-10-09 |
Family
ID=12744638
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19880104657 Expired EP0284046B1 (en) | 1987-03-27 | 1988-03-23 | Sheet feeder |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0284046B1 (en) |
JP (1) | JPS63154546U (en) |
CA (1) | CA1309428C (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TW555651B (en) * | 1998-04-14 | 2003-10-01 | Fuji Photo Film Co Ltd | Paper feeding cassette printer for use with paper feeding cassette and paper feeding method |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1005090A (en) * | 1973-04-18 | 1977-02-08 | Xerox Corporation | Reverse buckle sheet feeding apparatus |
SE425378B (en) * | 1980-04-25 | 1982-09-27 | Datasaab Ab | SET AND DEVICE FOR CREATING A STACK OF SHEET FORMS, EXAMPLE PAYMENTS, AND ANY SELECTED THESE FORMS |
-
1987
- 1987-03-27 JP JP4634887U patent/JPS63154546U/ja active Pending
-
1988
- 1988-03-23 EP EP19880104657 patent/EP0284046B1/en not_active Expired
- 1988-03-25 CA CA000562529A patent/CA1309428C/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPS63154546U (en) | 1988-10-11 |
EP0284046A1 (en) | 1988-09-28 |
CA1309428C (en) | 1992-10-27 |
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