Document feeders for printers and printers comprising the document feeders

Abstract

A document feeder for a printer may include an upper part and/or a lower part. The upper part may include a feeding roller arrangement configured to engage with an upper face of a document. The lower part may include a retaining surface. The lower part may further include a sliding element which, in at least an operation mode of the document feeder, may have a portion that projects with respect to the retaining surface for supporting a lower face of the document in such a way that at least a portion of the document is raised with respect to the retaining surface.

Claims

1. A document feeder for a printer, the document feeder comprising: an upper part; and a lower part; wherein the upper part comprises a feeding roller arrangement configured to engage with an upper face of a document, wherein the lower part comprises a retaining surface, wherein the lower part further comprises a sliding element which, in at least an operation mode of the document feeder, has a portion that projects with respect to the retaining surface for supporting a lower face of the document in such a way that at least a portion of the document is raised with respect to the retaining surface, and wherein the lower part is configured to move in such a way as to become recessed below a floor of a feeding opening of the printer.

2. The document feeder of claim 1, wherein the sliding element comprises a tooth configured to rotate around a rotation axis.

3. The document feeder of claim 1, wherein the lower part further comprises a spring configured to spring-load the sliding element in a projecting position.

4. The document feeder of claim 3, wherein the spring is preloaded with a load greater than or equal to 10 grams (g) and less than or equal to 30 g.

5. The document feeder of claim 1, wherein the sliding element comprises thermoplastic material.

6. The document feeder of claim 5, wherein the thermoplastic material comprises a blend of polyphenylene oxide and polystyrene.

7. The document feeder of claim 1, wherein the at least the portion of the sliding element that projects with respect to the retaining surface has a static coefficient of friction greater than or equal to about 1.0 and less than or equal to about 1.1.

8. The document feeder of claim 1, wherein the lower part is further configured to rotate.

9. The document feeder of claim 1, wherein the feeding roller arrangement comprises two motorized feeding rollers.

10. The document feeder of claim 9, wherein an outer surface of the two motorized feeding rollers is covered or lined with a rubber layer.

11. The document feeder of claim 9, wherein the feeding roller arrangement further comprises a trough between the two motorized feeding rollers.

12. A printer, comprising: the document feeder of claim 1; and a feeding opening comprising the floor.

13. The printer of claim 12, wherein the printer further comprises a sensor configured to detect presence of the document.

14. The printer of claim 13, wherein one document output is selected among a plurality of outputs according to a detected size of the document, and wherein the size of the document is detected based on the sensor.

15. The document feeder of claim 1, wherein the at least the portion of the sliding element that projects with respect to the retaining surface has a kinetic coefficient of friction greater than or equal to about 1.0 and less than or equal to about 1.1.

16. The document feeder of claim 1, wherein the feeding roller arrangement comprises two feeding rollers.

17. The document feeder of claim 16, wherein an outer surface of the feeding rollers is covered or lined with a rubber layer.

18. A document feeder, comprising: an upper part; and a lower part; wherein the upper part comprises a feeding roller arrangement configured to engage with an upper face of a document, wherein the lower part comprises a retaining surface and a sliding element, wherein the sliding element is configured such that, in an operation mode of the document feeder, a portion of the sliding element projects with respect to the retaining surface to support a lower face of the document so that at least a portion of the document is raised with respect to the retaining surface, wherein the lower part further comprises a spring configured to spring-load the sliding element in a projecting position, and wherein the spring is preloaded with a load greater than or equal to 10 grams (g) and less than or equal to 30 g.

19. The document feeder of claim 18, wherein the sliding element is further configured such that, at least in the operation mode of the document feeder, the portion of the sliding element projects with respect to the retaining surface to support the lower face of the document so that the at least the portion of the document is raised with respect to the retaining surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the present invention will be better understood by reading the following detailed description, to be read by referring to the accompanying drawings, wherein:

(2) FIG. 1 is a axonometric view of a printer according to an embodiment of the present invention;

(3) FIG. 2a is a simplified cross section of the printer of FIG. 1, with a document which is at about the beginning of the paper path;

(4) FIG. 2b is an enlarged view of a portion of FIG. 2a;

(5) FIG. 3a is a partial view of the printer, without the printer body, showing the improved document feeder according to an embodiment of the present invention in a first operation mode;

(6) FIGS. 3b and 3c are simplified cross sections of the improved document feeder according to an embodiment of the present invention in the first operation mode;

(7) FIG. 4 is a view as the one of FIG. 3b for the second operation mode;

(8) FIG. 5a is a view corresponding to FIG. 3a for the third operation mode;

(9) FIG. 5b is a simplified cross section of the improved document feeder according to an embodiment of the present invention in the third operation mode;

(10) FIG. 6 is a simplified front cross section of the improved document feeder according to an embodiment of the present invention in the first operation mode with a document;

(11) FIGS. 7a, 7b and 7c are simplified axonometric views of the lower component of the improved document feeder according to an embodiment of the present invention; and

(12) FIG. 8 is a view of an exemplary document which is glued along a lateral side.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

(13) FIG. 1 schematically shows a printer 1 according to an embodiment of the present invention. The printer 1 comprises a main body 11. The printer comprises a feeding opening 12 for feeding one or more documents D to the printer and an upper output paper tray 14. Additional output paper trays or output paper trays arranged in different positions could be provided without changing the scope of protection of the present invention. A document D, after being printed, could be also returned to the feeding opening.

(14) For the present description and claims, the term document will indicate a layer of material to be threated. Such a layer of material may comprise one or more sheets. The sheets may be connected (typically glued) together along a front edge or a lateral edge. The sheet(s) may be at least partially pre-printed or may be white sheets (without any characters and digits thereon). The sheet(s) can be essentially made of, or can comprise, paper or the like. FIG. 8 shows an exemplary document D formed by two sheets S1, S2 which are glued along only a lateral side (left side in FIG. 8). At the opposite lateral side, the sheets S1, S2 are not connected together as it is shown in FIG. 8. The two sheets are also not connected along leading edge LE and trailing edge TE.

(15) FIGS. 2a and 2b are cross sections of a printer provided with an improved document feeder ADF according to an embodiment of the present invention. While the various parts will become more clear with reference to other Figures (showing enlarged parts), it should be first remarked that the printer comprises a feeding opening 12 with a corresponding feeding opening edge 12 and a feeding opening floor 12 on which a document D is laid.

(16) The document D is shown with enlarged thickness for improving clarity. Also shown in FIG. 2b is an axis 13 of document position detectors 13 which are configured for detecting that a document D is present when it is between an infrared emitter and a corresponding receiver. Downwardly, there are provided alignment devices, printing arrangements and transportation means.

(17) In one embodiment of printer, the document output is selected among a plurality of documents outputs according to the detected size of the document. In turn, the size of the document may be detected based on sensor means (typically said infrared document detectors 13).

(18) FIG. 3a, is a partial enlarged view showing the feeding opening 12 of printer 1 with the printer body removed for a better view and understanding of the improved document feeder ADF according to an embodiment of the present invention.

(19) The document feeder ADF of the present invention can operate substantially according to three operation modes or also according to less than three operation modes. The first operation mode is adapted to feed a single document, possibly made of two or more sheets connected along an edge, which could be a lateral edge (FIG. 8). The second operation mode is adapted to feed a plurality of documents, arranged in a stack. The third operation mode is a manual mode for feeding documents manually. The three operation modes will be disclosed below.

(20) The improved document feeder ADF comprises an upper part 100 and a lower part 200 which will be described separately in the following description.

(21) The upper part 100 comprises a support plate 101 which is hinged around an axis 102 so that it can be rotated upwardly as shown at least in FIGS. 2b, 3a and 3b. The support plate 102 in turn supports a pressing roller 103 and a first gear wheel 104 which is coaxial with the pressing roller 103. An electric motor (not shown) transmits rotation movement to pressing roller 103 through the first gear wheel 104 and further gears 105, belts and/or chains.

(22) When the pressing roller is rotated downwardly (second operation mode) and it is caused to rotate, it transports the document which is in contact with towards the printing stages.

(23) In the first and third operation modes, the support plate is rotated upwardly and the pressing roller is in a non working configuration. In such a configuration, the pressing roller is either not caused to rotate or it is rotating but is anyway not engaging any documents. This because it is raised with respect to the floor 12 of the feeding opening 12.

(24) Preferably, the above mentioned motor is also connected to a feeding roller arrangement 110. A feeding roller arrangement 110 according to an embodiment of the present invention is also shown in FIG. 6. Feeding roller arrangement 110 may comprise a shaft 111 with two feeding rollers 112 mounted thereon. The feeding rollers 112 can be axially separated by a central throat or trough 115.

(25) In embodiments of the invention, the outer surface of feeding rollers 112 is covered or lined with a material 113 providing a rather high friction with a document. Such covering material 113 could comprise a rubber material. Such rubber material could be, profitably, similar to a track with a recursive pattern of blocks. Friction coefficient of the covering material could be about 1.0-1.1 in compliance with ASTM 0618 Standard Test Mode.

(26) The outer surface of feeding rollers 112 can be covered by a rubber such as EPDM 705 Shore A.

(27) The outer surface 113 of the feeding rollers 112 is at a distance from the floor 12 of the feeding opening 12.

(28) In embodiments of the invention, the throat 115 which is arranged axially between the feeding rollers 112 has an outer diameter lower than the diameter of the feeding rollers 112, possibly covered or lined as said above.

(29) The outer diameter of the feeding rollers 113 (including the friction lining) can be from about 16 mm to about 20 mm. In one embodiment, the feeding roller diameter is about 19 mm0.2 mm.

(30) The outer diameter of the trough 115 can be from about 14 mm to about 18 mm. In one embodiment, the trough diameter is about 16 mm0.1 mm.

(31) Profitably, the shaft 111 can be made in two sections.

(32) The feeding rollers 112 can be made of a plastic material such as a thermoplastic material. In one embodiment the feeding rollers can be made of a blend of polyphenylene oxide (PPO) and polystyrene (PS). A preferred material is Noryl SE 1, GFN2, FN 215 or any other polyphenylene ether. Alternative materials could be: ABS (Acrylonitrile butadiene styrene) polymer, PET, LDPE, MDPE or HDPE or a resin material or a combination thereof.

(33) As said above, the improved document feeder ADF comprises also a lower part 200 cooperating with the upper part 100 for properly feeding certain documents D (as the document D of FIG. 8). The lower part 200 comprises a slide shoe 201 which, in operation, can (at least partially) project upwardly from a floor 12 of the feeding opening 12. The slide shoe 201 is also shown in FIGS. 7a, 7b and 7c. It can have a substantially concave shape with an upper retaining surface 202, two lateral sides 203 and an open lower surface 204. The upper surface 202 and the two lateral sides 203 delimit a volume 205 which is open at the bottom 204.

(34) In use, the upper retaining surface 202 of the slide shoe 201 faces the feeding rollers 112 of the upper part 100 of the improved document feeder ADF of the present invention.

(35) Two pins 207 project outwardly, in opposite directions, from the lateral sides 203 of the slide shoe 201. The pins 207 lay on a common axis.

(36) A C shaped arm 208 is connected to the slide shoe 201 and projects downwardly.

(37) The lower part 200 of the improved document feeder ADF comprises also a sliding element 210, such as sliding teeth 210. The sliding teeth 210 is arranged so that in at least one operation condition, it projects partially from the upper retaining surface 202 of the slide shoe 201 through a window 211. Preferably, the sliding teeth 210 and its window 211 are arranged centrally with respect to the lateral sides 203 of the slide shoe 201.

(38) As shown in FIG. 7b, the sliding teeth 210 is mounted rotatable around an axis 213 extending in the open volume 205 of the slide shoe 201 from one lateral side 203 to the opposed one. The rotation axis 213 of the teeth 210 can be parallel to the rotation axis of the projecting pins 207. Preferably, a spring 214 is provided for maintaining the teeth 210 projecting upwardly with respect to the surface 202 of the slide shoe 201. When the teeth 210 becomes subject to a load higher than a threshold load, the sliding teeth 210 rotates downwardly within the volume 205 of the slide shoe and it does not project upwardly from the retaining surface 202 of the slide shoe 201. If the load is removed, the sliding teeth 210 returns back in the projecting position. The spring is preloaded. The preload can be from about 10 g to 30 g. In embodiments of the invention, the preload can be of about 20 g. In general terms, the preload corresponds substantially to the weight of a document to be singularly feed in the printer.

(39) Preferably, the projecting end of the sliding teeth 210 has a width substantially corresponding to the width of the trough 115. More precisely, the width of the sliding teeth 210 is such that it can engage with the friction surface 116 provided on the surface of the trough 115.

(40) Preferably, the upper retaining surface 202 of the slide shoe 201 is covered with, lined with or made of (at least partially) a material providing a rather high friction with a document, which is typically made of paper of the like. In embodiments of the invention, the material of the upper surface 202 of the slide shoe 201 may be of rubber or the like. Friction coefficient of the covering material could be about 1.0-1.1 in compliance with ASTM 0618 Standard Test Mode. The upper retaining surface 202 can be covered by a rubber such as EPDM 705 Shore A.

(41) Preferably, at least the projecting part of the sliding teeth 210 is made of a material providing a rather low friction with a document, typically made of paper or the like. In one embodiment, at least the projecting part of the sliding teeth 210 can be made of a blend of polyphenylene oxide (PPO) and polystyrene (PS). A preferred material is Noryl SE 1, GFN2, FN 215 or any other polyphenylene ether. Alternative materials could be: ABS (Acrylonitrile butadiene styrene) polymer, PET, LDPE, MDPE or HDPE or a resin material or a combination thereof.

(42) In other embodiments, the sliding teeth 210 can be replaced by a small wheel, a roller or the like.

(43) According to the first operation mode (FIGS. 3b, 3c and 6), the outer surface 113 of the feeding rollers 112 is at a distance from the retaining surface 202 of the slide shoe 201. In other words, the feeding rollers 112 are not in contact with the retaining surface 202 of the slide shoe 201. The distance between the surface 202 and the rubberized outer surface 113 of the feeding rollers 112 can be of about 1 to 2 mm. However, the sliding teeth 210 is projecting upwardly in the trough 115.

(44) When a document D to be processed by the printer 1 is fed to the document feeder ADF in the first operation mode, the document D is slidingly supported by the projecting sliding teeth 210 and gently pushed upwardly towards the feeding rollers 112. However, the lower face of the document is not retained by the rubberized retaining surface 202 of the slide shoe 201, due to the projecting sliding teeth 210.

(45) This operation mode is particularly profitable and convenient for feeding multi-copy documents because the lower sheet of the document is not retained with respect to the upper sheet. Therefore, it can be used for multi-copy documents connected along a lateral edge and not along a leading edge. Advantageously, peeling of the sheets does not occur.

(46) The first operating mode can be selected manually, for instance by pressing a proper button. As an alternative, it can be automatically selected through use of proper sensor(s).

(47) According to the second mode (FIG. 4), the rubberized outer surface 113 of the feeding rollers 112 is substantially in contact with the retaining surface 202 of the slide shoe 201. In principle, the sliding teeth 210 is projecting upwardly in the trough 115 but this has no influence with the transport of the document. In fact, the document maintained between the feeding rollers 112 presses the sliding teeth 210 downwardly. This operation mode is particularly profitable and convenient for feeding single-sheet documents which become sandwiched between the rubberized surfaces 113 of the feeding rollers 112 and of the retaining surface 202 of the slide shoe 201. The single-sheet documents can come from a stack of documents (not shown). The top document of the stack is provided by the pressing roller 103 of the upper part 100 of the document feeder ADF.

(48) The third operation mode is shown in FIGS. 5a and 5b (as well as in FIGS. 2a and 2b). According to this third mode, the lower part 200 of the document feeder ADF is rotated so that it becomes recessed below the floor 12 of the feeding opening 12. In this configuration, it does not obstacles any document fed into the printer 1. Such documents can be fed manually.

(49) The third operation mode is adapted to feed into the printer documents having a larger size than the size of the documents fed in the first operation mode. Such documents can be, for instance, documents having an A4 size or a similar size. The documents can be fed manually by a user who can properly arrange them at the alignment device(s) without being obstructed by the shape of the feeding opening 12.