DE19621071A1 - Sheet dispenser for a printer - Google Patents

Abstract

Opposite lateral edge portions of a sheet P, discharging from a printer to a tray 18, are supported from beneath by respective support portions, at least one of which includes a roller 91a. The roller(s) may be driven to propel the sheet or rotate in response to sheet movement. The central region of the sheet is depressed by roller 19. The widthwise position of support portion 81 may be adjusted and, if it is moved to within a predetermined adjustment range, the portion 81 flips into a non-operative position and exposes a lower support portion (not shown) which takes over the support function.

Description

The present invention relates to a Sheet dispenser for a printer.

Inkjet printers are generally designed so that they sign by ejecting a steel from drops of ink generate on sheets. If characters are continuous on one Multiple sheets to be printed will be a subsequent one Sheet fed into the printer before the ink on the printer previous sheet dries completely. Therefore, if after Output the following sheet against the printed side of the previous sheet rubs, smear the ink.

An inkjet printer design that has tried Solving this problem is unexamined in Japanese Patent publication 91861/1994.

A perspective view of the sheet discharge section 690 of this ink jet printer is shown in Figs. 27-30. The output section 601 comprises a frame 614 , which comprises a pair of integrally formed support sections 612 a and 612 b thereon. The support sections 612 a and 612 b guide and support from below each side area of a sheet P which has previously been printed on an upper side by means of a print head (not shown) and is currently being output. The support sections 612 a and 612 b can be thin, integrally formed, immovable rib-like elements whose respective upper sides 612 a ', 612 b' are inclined upwards in the sheet discharge direction. A transport section, generally designated 606 , includes a plurality of output rollers 682 for outputting sheet P, which is ultimately output onto output plate 605 , which may be rotatably mounted with respect to output frame 614 . Also located below the output rollers 682 are drive rollers 607 which advance the sheet by touching the underside of the sheet.

An arm, generally designated 613 a, is rotatably attached to a frame (not shown). The arm 613 a comprises a depressing section 613 which is rotatably held thereon and which can have the shape of a thin, plate-like star wheel. The depressing section 613 exerts a downward force on the central part of the sheet P which is being discharged from the discharging section 601 .

The sheet discharge operation in this conventional type of printer will now be described. The sheet P is printed in the printing section (not shown) and comes into the output section 601 . At this time, each side of the sheet P is led up through the tops 612 a 'and 612 b' of the respective support portions 612 a and 612 b. At the same time, the middle part of the sheet gradually comes under the depressing section 613 and, although the middle part of the sheet P exerts an upward force on the depressing section 613 and the rotating arm 613 a, due to the load on the middle part of the sheet P. Weight of the depressing section 613 and the arm 613 a driven down. As a result, the sheet P is inevitably driven into a concave shape when viewed in the discharge direction. This type of concave shape can also be achieved without a depressing section since the weight of the sheet can cause its concavity. Nonetheless, when the sheet P is forced into this concave shape, it will stiffen and advance in the dispensing direction as if it were floating. For this reason, as particularly shown in Fig. 28, the time until the discharged sheet P slidably contacts a printed surface P1f from sheet P1 (the sheet previously printed, discharged, and stacked on a sheet discharge tray 605 ) will be delayed. This method of delaying the contact of the subsequent sheet with the previously ejected sheet allows the ink enough time to dry on the printed sheet P1 before contacting sheet P.

Fig. 29 shows the sheet P after it has been further discharged from the discharge section 601 and its rear edge Pb has passed through the transport section 606 . At this point, the sheet P loses its transport force in the discharge direction because the discharge rollers 682 cease to act on the sheet P. The rear portion Pc of sheet P is, however, by the downward force of the depression portion 613 on the central part of the rear portion Pc of sheet P and the upward force of the support portions 612 a, 612 b on the sides of sheet P in its kept concave state.

As shown in FIG. 30, a subsequent sheet P2 is driven forward by the discharge rollers 682 upon entering the transport section 606 , and thus its leading edge P2a passes the transport section 601 . When the leading edge P2a contacts the trailing edge Pb of the previous sheet P, the previous sheet P is stacked on the previously printed sheet P1 ( Fig. 28). The time until sheet P2 contacts printed sheet P1 is delayed in the same manner as described for sheet P above.

When a relatively stiff sheet such as an envelope or a postcard is used in a conventional ink jet printer, the stiff sheet may be outputted due to the friction it experiences while being over the tops 612 a 'and 612 b' of the support portions 612 a and 612 b moved, emerge unevenly. Because the stiff sheet resists bending and the tops are relatively high, the stiff sheet will become unreliable and may jam.

The present invention is therefore based on the object a sheet dispenser for a printer is available which has the disadvantages mentioned above and Overcomes limitations and leaves of different sizes and Art issues, supports and guides without any problems.

This object is achieved by the invention Sheet output device according to the independent Claim 1. Further advantageous embodiments of the Sheet dispenser according to the invention result from the dependent claims, the description and the Drawing.

The present invention relates generally Inkjet printer and especially an improved one Inkjet printer that is designed to be more accurate and reliable sheets, including one Output the sheets without smearing the ink the sheets already output.

The sheet dispenser according to the invention is in the hereinafter also referred to as the sheet discharge section.

A printer includes a pair of support sections to support to support both side areas of a sheet below, the after printing characters on the surface of the sheet by means of a printing section which is an ink jet head has to be output. At least one of the  Sections of the pair of support sections is a roller, the one Drive roller for feeding the emerging sheet or can be a driven roller which by contact is rotated with the emerging sheet. Also one of the Support sections a drive roller for driving the out stepping sheet while the other support section is a driven roller, which by contact with the emerging sheet is rotated. After all, both can Support sections drive rollers or driven rollers.

One aspect of the present invention is to provide a improved printer that prints sheets more reliably can.

Another aspect of the present invention is Creation of an improved printer that prints sheets can without ver ink on previous sheets ver is lubricated.

Yet another aspect of the present, to solve the The invention made above problems is the Creation of a printer that is able to stiff itself Output sheets quickly and evenly without the Accuracy of the sheet feed is reduced and without the surface of the output sheet with striking Traces of ink is stained.

Yet another aspect of the present invention is that Creation of an inkjet printer that reliably leaves can output different sizes and types.

Further aspects and advantages of the invention result from the description.

The invention thus includes the design features Combination of elements and arrangement of parts in  the construction set forth below by examples are explained.

For a better understanding of the invention, reference is made to the following Description in conjunction with the accompanying drawings Referred to, whereby:

Fig. 1 is a sectional view of an inkjet printer that is constructed according to a first embodiment of the present invention;

Figure 2 is a partial top view of the ink jet printer constructed in accordance with the invention;

Figure 3 is an enlarged sectional view of part of the ink jet printer constructed in accordance with the present invention;

Figure 4 is an enlarged sectional view of part of the ink jet printer constructed in accordance with the present invention;

Figure 5 is an enlarged fragmentary sectional view of the printer constructed in accordance with the present invention;

Figure 6 is an enlarged top view of part of the printer constructed in accordance with the invention;

Fig. 7 is an enlarged front view of a switch according to the invention, showing a support constructed according to the invention in the upright position and in a non-supporting position (dashed);

Fig. 8 (a), 8 (b) and 8 (c) are enlarged schematic elevational views of a support portion and the switch according to the invention acting are;

Figure 9 is a sectional view taken along line 9-9 of Figure 5;

Figure 10 is a rear view of a connection plate constructed in accordance with the invention;

Fig. 11 (a) is a top view of part of the printer constructed in accordance with the invention;

Fig. 11 (b) is an elevation of part of the printer constructed in accordance with the invention;

Figure 12 is an enlarged, partial top view of part of the printer of Figure 11 (a) constructed in accordance with the present invention;

Fig. 13 is a sectional view taken along line 13-13 of Fig. 12;

Fig. 14 is a sectional view taken along line 14-14 of Fig. 12;

Fig. 15 (a) and 15 (b) are schematic views of a wavy sheet are that passes under the printing section according to the prior art;

Figure 15 (c) is a schematic view of a sheet passing between the pressure section and a regulating element constructed in accordance with the invention;

Fig. 16 (a) and 16 (b) are schematic views showing the action of various sheet discharge rollers;

. 17 (a) is shows a schematic view of a constructed in accordance with the prior art ribs Bishe ring member;

. 17 (b) is a schematic view of Fig illustrating a constructed according to the present invention rib member;

Fig. 18 (a) and 18 (b) are perspective views of of the present invention constructed toothed roller;

FIG. 19 is a perspective view of the sheet discharging section according to the present invention;

FIG. 20 is a perspective view of the sheet discharge portion during a sheet discharging operation;

Fig. 21 is a perspective view of the sheet discharge section during the sheet discharge operation;

Fig. 22 is a perspective view of the sheet discharge section during the sheet discharge operation;

Figure 23 (a) 1, 23 (b) 1, 23 (c) 1 and 23 (d) 1 are a series of schematic plan views illustrating the operation of the sheet dispenser assembly.

Fig. 23 (a) 2, 23 (b) 2, 23 (c) 2 and 23 (d) 2 are schematic elevational views of the respective plan views showing the operation of the sheet dispenser assembly;

Fig. 24 is a perspective view of the sheet discharge section during the sheet discharge operation;

Fig. 25 is a perspective view of the sheet discharge section during the sheet discharge operation;

Fig. 26 (a) is a sectional view of the sheet dispenser assembly according to a second embodiment;

Fig. 26 (b) is a sectional view of a printer constructed according to the second embodiment; and

Figures 27-31 illustrate printers constructed in accordance with the prior art.

Reference is first made to FIGS. 1 and 2, which illustrate a printer body, generally designated 10 , of a printer, which may be an inkjet printer, for example, and is constructed in accordance with a first embodiment of the present invention. The printer body 10 comprises a printer housing 11 , in which an automatic sheet feeder 20 is arranged. In particular, the automatic sheet feeder 20 is arranged in the upper rear area of the printer body 10 .

Generally speaking, a sheet P is fed to the printer body 10 from the automatic sheet feeder 20 . The printer body 10 includes two sheet feed rollers 30 rotatably mounted in the body 10 and driven pinch rollers 40 rotatably mounted in the printer body 10 and in pressure contact with the sheet feed rollers 30 . A regulating element 50 for guiding the underside of a sheet is mounted in the printer body 10 . A printhead 60 for dispensing ink on a sheet is mounted on a reciprocating carriage 61 which faces the regulating member 50 separated by a gap. A guide roller 75 for driving the sheet through the discharge section is rotatably mounted in the printer body 10 . At least one output roller pair 71 and 72 is rotatably mounted in the printer body 10 . An output section, generally designated 120 , is mounted in the printer body 10 along the sheet feed path PP for the sheet P (see Fig. 3). The output section 120 is arranged in the front lower region of the printer body 10 . An output tray 18 for stacking the sheets discharged from the output section 120 is arranged separately from and below the output section 120 .

The printer body 10 also includes an underside frame 12 within the printer housing 11 , which preferably consists of a metal plate and serves as a protective plate, a left-hand frame 13 and a right-hand frame 14 , which are preferably made of plastic and are arranged in the lower frame 12 . An intermediate frame 15 made of a metal plate is arranged inside the side frames 13 and 14 . A subframe, generally designated 16 , is mounted within the printer housing 11 and is preferably made of plastic. The subframe 16 fixes each of the frames described above in its correct position.

Furthermore, the subframe 16 includes a lower plate 16 a, which forms a lower part of the sheet feed path PP ( Fig. 3), a rear plate 16 b, which is integrally formed with the lower plate 16 a, and Be tenplatten 16 c and 16th c ', which are formed in one piece with the lower plate 16 a and the rear plate 16 b and, as shown in Fig. 2, are on opposite sides of the printer body 10 . A plurality of rib-shaped sheet guides 16 e protrude from the top of the lower plate 16 a.

The automatic sheet feeder 20 includes a grooved sheet feed roller shaft 21 which is rotatably held in the side plates 16 c and 16 c 'of the sub frame 16 , and is rotatably driven at the time of sheet feeding by a gear mechanism (not shown) connected to a drive mechanism 100 is. Two sheet feed rollers 21 a and 21 b are rotatably mounted on the sheet feed roller shaft 21 . The sheet feed rollers 21 a and 21 b are both preferably constructed as D-shaped rollers with an outer rubber surface layer. The automatic sheet feeder 20 also includes a feeder 22 , an edge guide 23 and a sheet feeder 24 .

The feed means 22 comprises a lower plate 22 a for supporting a lower surface of a sheet, with the lower plate 22 a integrally formed side plates 22 b (of which only one side is shown as an example in Fig. 1), also with the lower plate 22nd a integrally formed triangular side plates 22 c (of which only one side is shown as an example in Fig. 1) and pins 22 d integrally away from the side plates 22 b and 22 c gene. The pins 22 d engage in elongated slots 16th d a, which are formed in the side plate 16 c of the subframe 16 , and thereby enable the feed means 22 to move diagonally up and down with respect to the subframe 16 . Feed means springs 25 are provided between the feed means 22 and the lower plate 16 a of the subframe 16 and drive the feed means 22 with respect to the subframe 16 in a diagonally upward direction. Furthermore, the feed means springs 25 can be arranged substantially below (see FIG. 1) the sheet feed rollers 21 a and 21 b. A cam mechanism (not shown) is functionally connected to the drive mechanism 100 and is arranged in the side plates 16 c and 16 c 'of the subframe 16 in order to press the feed means 22 against the spring force of the feed means springs 25 . When sheets are fed, the feed means 22 is pushed up by the feed means springs 25 , whereby the sheet is pushed toward the sheet feed rollers 21 a and 21 b. After the sheet has been fed to the sheet feed rollers 21 a and 21 b, the feed means 22 is driven downward by the downward force provided by the cam mechanism and thus moves in relation to the sheet feed rollers 21 a and 21 b below, which prevents sheets from being fed to the sheet feed rollers 21 a and 21 b.

The edge guide 23 comprises a lower plate 23 a, a bent part 23 b, which is arranged in the front edge region of the lower plate 23 a, a clamping portion 23 c, which is provided in the rear part of the edge guide 23 , a side plate 23 d, the is connected to the lower plate 23 a, and a connecting plate 26 . The edge guide 23 is slidably mounted on the feed means 22 by engagement of the bent part 23 b with a groove 22 e in the lower plate 22 a. The clamping portion 23 c wraps around the rear portion (the upper end portion) of the feed means 22 and holds the edge guide 23 in place. The side plate 23 d of the edge guide 23 aligns the left edge of a sheet (not shown) placed on top of the feed means 22 . The right side of the sheet is guided by the inner surface in the upper region of the side plate 16 c on the right side of the sub-frame 16 .

As shown in Fig. 1, the sheet supply tray 24 is attached through a hole formed in the lower portion of the sheet feeding tray 24 insert 24 a detachably attached to the printer body 10. The insert 24 a is inserted into an insert slot 11 which is provided in the housing 11 of the printer body 10 . When the sheet feed tray 24 is inserted into the housing 11 , the sheet feed tray 24 cooperates with the feed means 22 to support the underside of a sheet. When the automatic sheet feeder is not operating, that is, when the feeder 22 is depressed due to the cam mechanism described above, the sheet loading operation in the automatic sheet feeder 20 requires the insertion of one or more sheets an upward direction into the sheet feed tray 24 .

When the automatic sheet feeder 20 operates with the sheet loaded in the sheet feed tray 24 , the cam mechanism releases pressure on the feeder 22 and causes the feeder 22 to be urged upward by the feeder springs 25 . This upward movement of the supply means 23 brings only the uppermost sheet in the feeding means 22 with the sheet feed rollers 21 and 21 b in contact. In this way, a single sheet is transported to the sheet feed path PP.

As shown in FIGS. 2 and 11 (a), a sheet feed roller shaft 31 is rotatably supported by the side frames 13 and 14 and driven by the drive mechanism 100 to rotate. The sheet feed rollers 30 are preferably two comparatively long, round, rod-shaped rubber rollers which are rotatably mounted on the sheet feed roller shaft 31 . When the shaft 31 is driven by the drive mechanism 100 , the shaft 31 and the sheet feed rollers 30 rotate, causing the sheet to advance one line each time. Before each sheet feed, printhead 60 and drive mechanism 100 cooperate so that printhead 60 moves across the sheet and is arranged for printing the next print line.

As shown in more detail in FIG. 3, holders 41 , which comprise integrally formed projecting areas 42 , act as sheet guides and form the upper part of the sheet feed path PP. As shown in Figs. 1 and 2, a pair of hooks 44 are formed in the upper part of the holders 41 . These hooks hold the holders 41 in place on the intermediate frame 15 in such a way that the holders 41 are able to swing. Rectangular windows 42 a are formed in the areas 42 of the holders 41 . A shaft 40 a is rotatably held and is able to move in the directions shown by arrow X within the rectangular window 42 a. The pinch rollers 40 are preferably round, rod-shaped metal rollers, are held on the shaft 40 a and are opposite the sheet feed rollers 30 . In a preferred embodiment, four pinch rollers are provided for each sheet feed roller 30 . Springs 45 are provided between the holders 41 and the intermediate frame 15 . As shown in Fig. 3, the pinch rollers 40 touch the sheet feed rollers 30 at a position g which is slightly downstream in the sheet transport direction from a position which is referred to as the highest point 30 a of the sheet feed rollers 30 . This slightly forward-facing arrangement of the pinch rollers 40 , which is caused by the driving force of the springs 45 , enables ge together with the way in which the shaft 40 a is held (see above) that the pinch rollers 40 with an auto matic Centering function abuts the sheet feed rollers 30 when the pinch rollers 40 are driven to rotate by the sheet feed rollers 30 .

A regulating element 50 is fastened in the lower frame 12 and is arranged on the underside of a sheet P transported by the sheet feed rollers 30 . The regulating element 50 comprises a horizontal flat part 51 f, which is arranged opposite the print head 60 , and a plurality of ribs 51 , which project integrally upwards from the horizontal part 51 f. The ribs 51 extend perpendicular to the sheet transport direction and have an upwardly inclined surface 51 b, a b adjacent to the upwardly inclined surface 51 of upper surface 51 a and a subsequent sloping surface 51 d of the upper surface 51. Viewed from the side, as shown in Fig. 3, these surfaces form a substantially trapezoidal profile and expand in the sheet transport direction.

The sloping surface 51 b leads the leading edge of a sheet fed by the sheet feed rollers 30 . The upper surface 51 a touches the underside Pb of the sheet and regulates the gap between the sheet P and the print head 60th The guide portion 51 e is provided on the upstream side of the discharge rollers 71 and 72 and is arranged downstream of the ribs 51 . The guide portion 51 e guides the leading edge Pf of the sheet P toward the discharge rollers 71 and 72 and is preferably seen only on the upstream side of the discharge rollers 71 and 72 .

As shown in Fig. 1, hold and guide the guide rail 62 and the upper edge 15 a of the intermediate frame 15, the carriage 61st The print head 60 is mounted on the carriage 61 . The carriage 61 reciprocates by a driving force from a carriage motor (not shown) in a direction perpendicular to the sheet transport direction. A monochrome ink tank 63 and a color ink tank 64 can both be attached to the carriage 61 side by side in a direction perpendicular to the sheet transporting direction so that the print head 60 can perform color printing.

As shown in Fig. 2, a shaft 71 a is rotatably held in a side plate 52 of the regulating element 50 . Along the width of the sheet feed path, several pairs of output rollers 71 and 72 (7 pairs are shown in Fig. 2) are arranged. The rollers 71 are rotatably mounted on the shaft 71 a. The roller 71 of one end of the output roller pairs 71 and 72 is preferably made of a rubber roller and is driven by the drive mechanism 100 to rotate by a gear mechanism (not shown). The rollers 71 touch the rollers 72 , which can be thin, plate-like star wheels, but are preferably toothed rollers driven to rotate. As shown in Fig. 18 (a), each toothed roller 72 is supported on a round rod-shaped coil spring 73 (which functions as a shaft) and is supported by a support plate 53 which is mounted in the printer body (see Figs. 3 and 12 ). The toothed roller 72 contacts the roller 71 by the spring force of the coil spring 73 . In the case of thick sheets such as envelopes, the toothed roller 72 does not press firmly against the sheet so that the sheet transporting operation is hindered, but rather moves upward as shown in Fig. 18 (b). The rotational speed of the output roller pairs 71 and 72 , which corresponds directly to the transport speed of the sheet, is set so that the linear speed of the sheet through the output rollers 71 and 72 is faster than the linear speed of the sheet through the sheet feed rollers 30 . As a result, when the leading edge of the sheet P reaches the discharge rollers 71 and 72 , the sheet is taut between the discharge rollers and the sheet feed rollers.

The upper surface 51 a of the ribs 51 of the regulating element 50 is viewed slightly downstream from the print head 60 in the sheet transport direction. This causes the sheet P to be driven toward the head 60 . When the front and rear portions of the sheet P via the regulating element run 50, they are in their further transport by the sheet supply rollers 30, pinch rollers 40 and discharge rollers 71 and 72 pressed against the regulating member 50 downwardly. The underside Pb of the sheet reliably contacts the upper surface 51 a of the ribs 51 .

The support plate 53 comprises an integrally formed arm 54 which slopes downwards from it. A guide roller 75 is rotatably attached to the end of the arm 54 . The guide roller 75 is arranged between a printing section A and the output roller pairs 71 and 72 . The Druckab section A prints a printing sheet of a suitable recording medium such as paper. In the undesirable situation of curling of sheet P, the sheet contacts the guide roller 75 and is guided to the pairs of output rollers 71 and 72 . The guide roller 75 is preferably small in diameter and may be located near the print head 60 so that it is able to more accurately guide a wavy sheet. The guide roller 75 is preferably made of a water-repellent plastic and, as shown in Fig. 2, can be positioned so that it contacts a thick sheet like an envelope in the middle of its width.

It is therefore apparent from Fig. 1 that when a sheet P is fed from the automatic sheet feeder 20 , passes through the concave curved sheet feed path PP and reaches the sheet feed rollers 30 , the feed angle is regulated by the pinch roller 40 as it is fed over the sheet feed roller 30 becomes. The leading edge of the sheet P is guided by the regulating element 50 , which also acts as a guide element. The sheet P is guided so that its bottom Pb touches the upper surfaces of the ribs 51 a, which are formed on the tops of the regulating element 50 , and so that the gap between the surface of sheet P and the print head 60 is regulated, while ink is being discharged from the printhead 60 onto the top surface Pa of sheet P and printing is taking place. The printed sheet P passes through the discharge roller pairs 71 and 72 and the discharge section 120 and is discharged onto the discharge tray 18 .

As shown in Fig. 2, the discharge section 120 includes a roller 19 which presses down the center of a sheet, a slider 84 , which will be discussed below, and first and second support assemblies 80 and 90 , the respective side portions from below support from the discharge roller pairs 71 and 72 of the discharged sheet. As shown in FIGS . 11-14, the support assembly 90 , which will be discussed in more detail below, includes a drive roller 91 and a guide plate 92 .

Reference is now made to FIGS. 5-7, which illustrate a displaceable support arrangement 80 of the output section 120 in more detail. The support assembly 80 is mounted on the slider 84 and can be moved in a direction perpendicular to (along the width of the) sheet feed path PP. The support assembly 80 also includes first and second support members 81 and 82, respectively. The first support member 81 is used to guide and support a first end (as viewed from a leading edge of the emerging sheet) of a relatively flexible sheet such as an ordinary A4 or B5 sheet, and is supported from below while the second support member 82 is used to guide and support the first end of a relatively solid copy sheet such as envelopes and postcards.

As shown in FIGS. 5 and 6, a shaft 81 is mounted a rotatably to the slider 84 and is element to the first support 81 formed in one piece. The shaft 81 a can be both rotated and moved in each of the arrow directions X1 and X2. A disk-like arm 81 e is integrally formed on the rear edge of the shaft 81 a of the support member 81 ge. An upper pin 81 f and a lower pin 81 g each protrude integrally from the upper and lower rear portions of the arm 81 e. The shaft 81 a is provided with a tension spring 83 , one end 83 a of which is held by the first support element 81 , the other end 83 b of which is held by the slider 84 . The tension spring 83 exerts a force on the first support element 81 in the direction of the arrow X1 and also drives the first support element 81 into an upright position, as will be discussed below.

As shown in Fig. 6 and 7, in the upstream side of the slider 84, a locking or a holding part 84 a is formed, and by a snap action, a lower portion 81 b of the first support member 81 engages with the locking part 84 a and is released from this. The locking part 84 a comprises two projecting areas 84 a1 and 84 a2 and a recess 84 a3, so that when the lower region 81 b engages with the recess 84 a3 of the locking part 84 a, the support element 81 in the same way as the support element 82 stands upright. If a threshold force is exerted on the upper region 81 c of the support element 81 by a changeover switch 59 , which will be described below, the lower region 81 b is pushed out of the recess 84 a3 of the locking part 84 a, and the shaft 81 a rotates at the same time in a counterclockwise direction and moves in the direction of arrow X2 (see Fig. 5), causing the support member 81 to fall into a lying, non-support position. . 6 and 7, the support member is shown in its upright and lying position 81 in Fig. The lying position of the support element 81 is indicated by dashed lines.

When the first support member 81 rotates more than a predetermined angle, the lower portion 81 b abuts the underside of the left projecting portion 84 a1 of the locking member 84 a to anchor the support member 81 in a lying position. That is, the locking part 84 a also forms the retaining part of the support element 81 . If a rotational force is exerted clockwise on the shaft 81 a by the changeover switch 59 described below, the first support element 81 stands upright in response to the force exerted by the tension spring 83 . The lower region 81 b comes into engagement with the recess 84 a3 of the locking part 84 a and holds the support element 81 in an upright position.

In the present embodiment, the upright position of the support member 81 is a support position in which the side portions of a sheet are supported from below. The lying position is a non-supporting position in which the side areas of a sheet are not supported.

As shown in Fig. 5, the upper edge surface 81 d of the support member 81 in the upright position forms a support surface which is gently inclined upward in the sheet feeding direction. The support surface d formed by the top edge 81 is located slightly higher than the output from the sheet discharge roller pairs 71 and 72 sheets, so that the copy sheet is conveyed in a slightly upward angle.

The switch 59 is integrally formed on the front of the defining member 50 . As shown in Fig. 7, the changeover switch 59 is provided in the displacement region of the displaceable support arrangement 80 and comprises a first and a second inclined plate 59 a and 59 b which form a controlling surface which acts as a guide body. The changeover switch 59 is provided at a limit position c between the areas B2 and B1. Area B2 corresponds to an area of sheet widths in which the side areas of a sheet require support by the support element 81 , while area B1 corresponds to an area of sheet widths in which the side areas of a sheet do not require support. As shown in Figs. 6 and 7, a rail 59 c extends from the lower end of the first plate 59 a and is integrally formed thereon to form an acute angle with it. A projection 59 d, which is formed at the junction of the first inclined plate 59 a and the rail 59 c, projects slightly below the rail 59 c. The first and second plates 59 a and 59 b are arranged so that they are slightly offset from each other in the vertical direction.

According to Fig. 7 and 8 moves the upper pin 81 f when the movable support assembly 80 is disposed within the region B2 and is moved from the position shown by line B5 position in the direction of arrow S to the area B1 out on the second plate 59 b and abuts the first plate 59 a (see Fig. 8 (a)), whereby the first support member 81 is rotated counterclockwise against the force of the spring 83 in the direction of arrow R2. At the time when the upper pin 81 f moves over the projection 59 b, the first support element 81 is rotated into its maximum lying position and the lower region 81 b of the first support element 81 abuts the underside of the left projecting region 84 , as indicated above a1 of the locking part 84 a, so that the support element 81 is easily anchored in the lying position. When a force is applied in the clockwise direction R1 on the first support element 81 , this is held in the lying position by the upper pin 81 f, which abuts the underside of the rail 59 c.

On the other hand, when the slider 84 moves as shown in Fig. 8 (b) in the direction of the arrow T toward B5, the upper pin 81 f reaches under the plate 59 a and abuts the second plate 59 b, and support assembly 80 moves from area B1, where support is not required, to area B2, where support is required. At this point, the upper pin 81 f no longer abuts the bottom surface of the rail 59 c, and the support member 81 rotates clockwise in the direction of the arrow R1 to the upright position. As a result, the support member 81 automatically comes to the lying or upright position when the left support assembly 80 is moved back and forth. As will be described below and shown in FIG. 8 (c), the first support member 81 can be manually placed in the upset position when, as seen in FIG. 7, it is to the left of the plate 59b .

As shown in Fig. 5, the second support member 82 comprises an upright piece which is integrally formed with the slider 84 and has a support surface 82 a which is inclined downward in the downstream direction of the sheet feed path and sheets discharged from the output roller pairs 71 and 72 supports. As shown in Fig. 7, the first support member 81 is crank-shaped so that its upper portion 81 c, when in the upright position, is disposed over the second support member 82 . Therefore, output sheets are supported by the first support member 81 when the first support member 81 is in the upright position as shown in FIG. 8 (a), and are supported by the second support member 82 when the first support member 81 is as shown in Fig. 8 (b), is in the upset position.

As shown in Fig. 5 and 9, the slider 84 is slidably mounted to the lower side frame 12. The slider 84 includes a base portion 84 d in its rear portion, a fitting portion 84 e which is slidably mounted on a bent portion 12 a in the front portion of the lower frame 12 , and a foot portion 84 f which is formed on the base portion 84 d and is guided from the top 12 b of the underside frame 12 . The slider 84 is slidably supported with respect to the underside frame 12 by the fitting parts 84 e and the foot part 84 f. An upper side 84 g of the base section 84 d is slidably supported by the lower side of a front plate 55 of the regulating element 50 .

The slidable support assembly 80 is operatively connected to the edge guide 23 of the automatic sheet feeder 20 by a link mechanism. The link mechanism includes a link rod 110 . A first pinion 111 is integrally formed at one end of the connecting rod 110 . A second pinion 112 ( FIG. 1) is integrally formed on a second end (edge guide side) of the connecting rod 110 . A first rack 56 is formed on an underside of the depending piece 57 of the regulating element 50 and is in engagement with the first pinion 111 . A second rack 16 f ( FIG. 1) is formed in the rear region of the lower surface 16 a of the subframe 16 and engages with the second pinion 112 .

As shown in FIGS. 5 and 9, a leading edge 113 of the connecting rod, which is located in the front portion of the first pinion 111, mounted in a portion in the base 84 of the slider d 84 shaft-receiving opening 84 formed held h. That is, a rear portion 114 of the first pinion 111 is rotatably supported by an upper surface 84 i of the rear portion of the base portion 84 d and a lower surface 58 a of the depending piece 58 of the regulating member 50 . The rear part 114 of the first pinion 111 is displaceable in a direction perpendicular to the sheet feed direction with respect to the lower surface 58 a of the depending piece 58 of the regulating element 50 .

As also shown in Fig. 1, a rear edge 115 of the connecting rod 110 is rollably supported by a lower portion of a bent portion 16 g of the rear plate 16 b. The rear edge 115 of the connec tion rod 110 can be moved by the engagement force of the second pinion 112 and the second rack 16 f. Next, 10 is as shown in Fig. Accurately formed a recess 26 a in the lower portion of the connecting plate 26. A rear part 116 of the second Rit cell 112 is rotatably held in this recess 26 a.

In this way, the rear part of the connecting rod 110 is rotatably connected to the edge guide 23 . In particular, the upper region 26 b of the connecting plate 26 is coupled to the edge guide 23 and moves together with this. Therefore, when a sheet is inserted into the automatic sheet feeder 20 and the edge guide 23 is moved in a direction perpendicular to the sheet feeding direction, the movement of the edge guide 23 is transmitted to the second rack 16 f through the above-described connection. The second rack 16 f is their turn with the second pinion 112 of the connecting rod 110 into engagement and causes thereby a rotation of the dung Verbin rod 110 and the first pinion 111th Finally, the first pinion 111 with the first rack 58 in one handle. In this way, the leading edge 113 of the connecting rod 110 is not affected by a bend of the connecting rod 110 . That is, the leading edge 113 moves substantially the same distance as the rear edge 115 , and the slider 84 and the left support assembly 80 move the same distance as the edge guide 23 (shown in phantom in Fig. 2). Accordingly, when the edge guide 23 is shifted, the left support assembly 80 is shifted; that is, the edge guide 23 and the support assembly 80 are properly aligned by one operation - the movement of the edge guide 23 .

If the left support assembly 80 runs along its movement on the changeover switch 59 , the first support element 81 is automatically brought into the lying or upright state. As set forth above, output sheets are supported by the first support member 81 while the first support member 81 is in the upright position, as shown by the solid line of FIG. 7, and are supported by the second support member 82 while the first Support member 81 is in the lying position, as shown by the dashed line thereof. Whether the support edge of the output sheet is supported by the first support element 81 or the second support element 82 is selectively determined in accordance with the width of the sheet by manually adjusting the edge guide 23 to a suitable guide position.

According to this embodiment of the invention, the position of switch 59 (the above-mentioned limit position C) is between a position in which a B5 sheet is arranged vertically and a position in which a postcard is arranged horizontally. In Fig. 7 is a labeled "B5" dashed line indicates the position of the upper surface 81d of the first support member 81 when a B5 sheet was vertically placed on the sheet feeding tray 24, while a marked "Postcard" dashed line the position the support surface 81 d of the first support member 81 indicates when a postcard has been placed horizontally on the sheet feed tray 24 . In other words, if the sheet feed tray 24 contains B5 size sheets and the user wants to exchange them for a postcard, the first support member 81 according to this embodiment automatically drops when the edge guide 23 is pushed to a position corresponding to the size of the postcard the lying position to allow the second support member 82 to support the issued postcard. As will be described later, moreover, the first support element 81 can be manually arranged in the lying position when, for example, envelopes are printed which exceed the size B5. When a sheet of size B5 is printed, the edge guide 23 is pushed into the area B1, and the support arrangement 80 coupled with this simultaneously slides into the B1 area and causes the lower pin 81 g of the first support element 81 to the second plate 59 b comes across. In this way, the first support element 81 automatically assumes an upright position. According to this embodiment, a third plate (not shown) similar to the second plate 59b is arranged in a position which corresponds to the size of an A4 sheet. When the edge guide 23 is shifted to print A4 size sheets after printing an A4 size envelope with the first support member 81 manually placed in the lying position, the left support assembly 80 and the edge guide 23 slide simultaneously to the right, and the lower pin 81 g of the first support member 81 abuts the third plate and causes the first support member 81 to automatically assume an upright position.

As shown in Figs. 11-14, a second support assembly 90 for supporting a second edge of a sheet opposite to the edge supported by the first support assembly 80 includes a drive roller 91 and a guide plate 92 for guiding the leading edge of a sheet drive roller 91 to guide. As shown in Fig. 12, the drive roller 91 includes a roller portion 91 a for supporting output sheets from below, a thin shaft portion 91 b, a thick shaft portion 91 c and a roller gear 91 d, which is coupled to the thick shaft portion 91 c. The drive roller 91 may be integrally molded from a synthetic resin. The roller portion 91 a is preferably made of a material with a high coefficient of friction such as rubber to effectively give the exiting leaves a driving force. The thin shaft portion 91 b is supported by a support portion 52 c, which is integrally formed on a base portion 52 b, which in turn is integrally formed with the regulating element 50 . The thick shaft portion 91 c is rotatably supported by a side plate 52 of the regulating element 50 . The drive roller 91 is thereby by the thin shaft portion 91b and the thick shaft portion 91c is rotatably supported and driven generally illustrated in Fig. 14 by a gear train 110 to rotate.

According to Fig. 14, the gear train 110 comprises a Blattzuführwalzengetriebe 32 which is mounted on the shaft 31 of a sheet supply roller 30, a sheet output gear 71b, which is a sheet discharge roller 71 mounted on the shaft 71, a first intermediate gear 93, which with the Blattzuführwalzengetriebe 32 and the sheet output gear 71 b is engaged, and a second intermediate gear 94 , which is in engagement with the sheet output gear 71 b and the roller gear 91 d. When the sheet feed roller shaft 31 is driven by the drive mechanism 100 in the sheet feed direction, shown by the arrows F, then the sheet feed roller gear 32 also rotates in the sheet feed direction, causing the first intermediate gear 93 to reverse in the direction of the sheet feed roller gear 32 Direction rotates, represented by the arrows G. The first intermediate gear 93 drives the sheet output gear 71 b in the sheet transport direction, which drives the second intermediate gear 94 in the direction opposite to the direction of the sheet output gear 71 b. Finally, the second intermediate gear 94 drives the roller gear 91 d, which, since it is attached to the roller portion 91 a, causes the roller portion 91 a to rotate in the sheet transport direction.

When the sheet P is discharged from the sheet discharge rollers 71 and 72 , the guide plate 92 guides the leading edge of the sheet P to the roller portion 91 a of the drive roller 91 . As shown in Fig. 13, the guide plate 92 is arranged so that it lies slightly below a line t, which connects the top of the output roller 71 and the top of the roller portion 91 a. As a result, the guide plate 92 has little resistance to sheet discharge.

In the conventional printer shown in Fig. 27, the support surface 612 a 'is shaped so that it is, as shown in Fig. 31, in the direction of the sheet width at the same position as the toothed roller 682 and part of the underside of the Sheet P touches. Thus, the side edge of the sheet P can bend upward, and the sheet P tends to be soiled by contact with the print head 660 .

In contrast, an exporting shown in Fig. 11 is approximately according to this invention, the form roller portion 91 is disposed in a direction of sheet width (inwardly) offset from the outer sheet discharge roller 72 '. Thus, instead of the sheet P curling toward the print head, the side edge of the sheet P is held down by the sheet discharge roller 72 ', and contamination thereof by contact with the print head 60 is prevented.

Furthermore, the problem of contamination of the side edge of sheet P has also occurred on the left side edge of sheet P in conventional printers. Therefore, according to this embodiment of the invention, the same arrangement as mentioned above has been applied to the position of the first support member 81 in the support portion 80 for supporting the left side portion of a sheet. Specifically, as shown in FIG. 2, the left side edge of an A4 size sheet is represented by the line A4e, and the broken line A4 represents the top edge surface 81 d of the support member 81 . Accordingly, the left side edge of a sheet of size B5 is represented by the line B5e, and the dashed line B5 represents the top edge surface 81 d of the support member 81 . As can be seen from Fig. 2, the upper edge surface 81 d is slightly inward with respect to the sheet output roller 72 A4 for depressing the left side edge of the sheet P when characters are printed on A4 sheets. Accordingly, the upper edge surface 81 is slightly inwardly d with respect to the sheet discharge roller 72 B5 to depress the left side edge of the sheet P, when characters are printed on sheets of size B5. In this way, the left side edge of the sheet P is prevented from being contaminated by contact with the print head 60 .

Incidentally, as shown in FIG. 2 above, this embodiment is capable of picking up sheets over a width as represented by M. In addition, although A4 is the maximum sheet size on which characters can be printed across the entire width, B4 sheets in width M can also be transported for printing purposes. Here, the left support assembly 80 at the left outer end of the printer front (in the position where the support assembly 80 is shown in a solid line) can be arranged beyond the width M. However, the left edge of the sheet P is not soiled because the print head 60 cannot reach this position.

Referring now to FIG. 5. On the support plate 53 , a holder 19 a is attached and is rotatably held within the output portion 120 . The holder 19 a comprises a guide sheet 19 b and a toothed roller 19 which is rotatably mounted in the holder 19 a. When the sheet P by the discharge roller pairs 71 and 72 is output, the leading edge abuts Pf to the leader sheet 19 b. The force of the sheet P against the guide sheet 19 b causes the holder 19 a to rotate in the direction indicated by the arrow Y. The leading edge Pf of the sheet P is b by the guide blade 19 driven downward and is directed by the toothed roller 19 through the output section 120th

An ink jet printer of this embodiment has following functioning and effect.

First, where the sheet P is fed into the printer, the size of the sheet used in the printer is adjusted on the feeding means 22 and the sheet feeding tray 24 . Thus, by setting the sheet size, the user automatically ensures that the sheet is properly supported when it is output. That is, when the user changes the sheet size, for example, from A4 to B5, and the side plate 23 d of the edge guide 23 is displaced such that it abuts against the edge of the blade, the coupling mechanism acts such that the support portion 80 of the output section 120 in slides into a position that provides proper sheet delivery support.

Second, when the printer is started, the automatic sheet feed unit 20 pushes sheets through the sheet channel PP. When the sheet P reaches the sheet feed rollers 30, it is discharged with a feeding angle that is defined by the clamp rollers 40 from the sheet supply rollers 30th Since the pinch rollers 40 automatically align to properly contact the sheet feed rollers 30 , skewed movement of the sheet P is prevented.

Third, as shown in Fig. 3, the leading edge of the fed from the sheet supply rollers 30 the sheet P by the oblique surface 51b of the regulating member out 50 upward and driven, while the gap between the sheet surface and the print head 60 through the lower surface Pb of the sheet P, which abuts the top 51 a of the rib 51 , is regulated. After printing on the top Pa of the sheet P by ink discharged from the print head 60 , the leading edge Pf of the sheet P moves to the discharge rollers 71 and 72 . Sheet P may be heavily curled at this stage of printing, and therefore, as shown in FIG. 4, a guide roller 75 is provided between printhead 60 and output roller pair 71 and 72 to more precisely re-feed sheet P onto output roller pair 71 and 72 to steer. That is, the leading edge Pf of the sheet is prevented from entering the space S between the print head 60 and the pair of discharge rollers 71 and 72 even when the sheet P is curled. Therefore, the sheet P does not touch the print head 60 and there is no paper jam.

Moreover, when thick sheets such as postcards or envelopes are to be printed, the position of the print head 60 is shifted upward, as shown by the broken line in Fig. 4. In this situation, the leading edge Pf of the sheet can enter the space S between the print head 60 and the output roller pair 71 and 72 more easily, since the gap between the lower surface 60 a (nozzle opening surface, ie ink discharge surface) of the print head 60 and the regulating element 50 becomes larger . The front edge Pf of the sheet P is, however, reliably prevented by the guide roller 75 from entering the space S between the print head 60 and the output roller pair 71 and 72 .

Moreover, since the sheet feed path PP is a curved sheet feed path, the size of the printer can be made smaller than a printer with a straight sheet feed path. That is, due to a curved sheet feed path PP, the leading edge Pf of the sheet P tends to easily enter the space S between the print head 60 and the discharge roller pair 71 and 72 , but in this embodiment, the sheet P through the guide roller 75 reliably to the discharge roller pair 71 and 72 is steered towards.

In addition, since the back Pb of the transported sheet P abuts the ribs 51 of the regulating member 50 , the gap between the print head 60 and the sheet P is regulated, and printing is carried out without the possibility of a paper jam. Also, the ribs 51 do not interfere with the transportation of the sheets because they are elongated when viewed in the sheet transportation direction. Since the plurality of ribs 51 are formed in a direction perpendicular to the sheet transporting direction, the ribs 51 take the bulge of the sheet into the spaces 51 s even if high density ink dots are formed on the sheet P and the sheet curls due to the ink moisture content between adjacent ribs 51 (see Fig. 15 (c)). Due to this construction, even if the sheet P is curled, it does not abut the print head 60 and the ink does not smear.

In particular, as shown in Figs. 15 (a) -15 (c), the distance L is the ideal gap distance between the printhead 60 and a sheet P that has not curled. The sheet P moves over the flat surface 51 f of the regulating element 50 . Where the gap between the sheet P and the print head 60 corresponds to the ideal gap L, when the sheet P curls due to its ink moisture content, the protruding areas Pc of the curled sheet P and the ink discharge surface 60 a of the print head 60 touch each other .

A contemplated method for solving this problem is shown in Fig. 15 (b), f the provision of a gap L1 between the flat surface 51 and the print head 60 which is larger than the above-mentioned gap L. If, however, the sheet is not curled and is thus located in a flat state, since the gap has been made L1 larger, the distance between the 60 (i.e., approximately the distance L1) is too large from the flat surface 51 f-run sheet and the print head, and therefore the ideal pressure gap cannot be reached. If the distance that the drops of ink emitted by the printhead 60 have to travel to strike the surface of the sheet is too large, the margin of error increases between the ideal point of impact and the actual point of impact on the sheet.

To overcome this problem, protruding ribs 51 protrude from the surface 51 as shown in Fig. 15 (c). In a situation where the ink density is comparatively low, that is, the sheet does not curl, the sheet P 'is in a flat state and is guided by the top of the ribs 51 , and the distance between the sheet P' and the Printhead 60 can be set to the ideal distance L mentioned above. In the case where high-density ink dots are formed on the sheet and the sheet curls due to the ink moisture contained therein, the sheet may swell, creating trough areas Pd. These trough areas Pd are accommodated in the spaces 51 s between adjacent ribs 51 . Therefore, even if the sheet P 'is curled, the protruding portions Pc ( Fig. 15 (b)) will not abut the print head 60 , thereby reducing the possibility of ink smearing.

Referring now to Figures 16 (a) and 16 (b). In all the rollers 71 of the roller pairs 71 and 72, it is preferable that the downwardly extending rubber roller 71 is not a long, round, rod-shaped roller (such as roller 71 '), but rather a plurality of narrow rollers, which run along the width of the sheet web are arranged. If the rollers 71 are narrow in width, even if, for example, a high ink moisture content causes the sheet P to curl and swell and creates trough areas Pd, sheet feeding will be much more effective if the trough areas Pd hang over the edges of the rollers 71 can. For example, as shown in Fig. 16 (b), it is desirable that the width of the rubber rollers 71 be kept as narrow as possible within a range that still allows accurate and reliable sheet feeding. An example of a preferred narrow roller is shown in Fig. 16 (b) as roller 71 ''. The width W of the rubber roller 71 '' is narrower than the shaft distance P1 of the curled sheet. In a preferred embodiment, the width of the roller 71 '' is about 5 mm. With this construction, the trough areas Pd of the curled sheet P can hang over the edges of the roller 71 ''. In contrast, the roller construction as shown in Fig. 16 (a), which shows a long roller 71 ', is not desirable. In this situation, the trough area Pd of the curled sheet P will rest on the roller 71 '. Therefore, even if the toothed roller 72 tries to depress the sheet P, the above portion Pc will remain in an elevated state.

Another advantage of the present invention is that when the sheet P contacts the discharge roller pairs 71 and 72 , due to the above-mentioned rotational speed difference between the rollers 71 and 72 and the sheet feed rollers 30, the sheet feed rollers 30 and the discharge roller pairs 71 and 72 are pulled tight. When high density ink dots are formed on the sheet P, the swelling of the sheet, even if the sheet curls due to the ink moisture content, is reduced by the tension force within the sheet P, and a more reliable printing operation is achieved. Further, the bulge of the sheet P while the regulating member 50 drives the sheet P toward the side of the print head and contacts the back Pb of the sheet P is kept a sufficient distance from the head 60 . Therefore, even if the sheet is curled, it does not touch the print head 60 and the ink smear is much less likely. In addition, since the bulge of the sheet is accommodated in the space 51s between adjacent ribs 51 , contact of the curled sheet with the print head 60 and subsequent smearing of ink in the above-mentioned manner is prevented more reliably.

Referring now to the following disclosure, reference is made to Figures 17 (a), 17 (b) to emphasize the following positive operational effects achieved by constructing the ribs 51 in a substantially trapezoidal shape. First, for example, in a serial printer which prints individual lines after sequential receipt of print data for individual lines from a host computer, it is necessary that sheets can be transported in the reverse direction (that is, a reverse transport can take place) because the printing area of large characters is larger than the printing range of standard characters. Therefore, the large characters are printed while the sheet is being fed in the reverse direction by a piecewise multi-pass printing method, that is, the head scans the length of the printing area A shown in Fig. 3 and the sheet passes through it. In this situation, it is necessary to feed sheets in the reverse direction to complete the printing of the large characters. If the ribs 51 were not trapezoidal when viewed from the side, but instead instead had, for example, a rectangular shape when viewed from the side (see Fig. 17 (a), rib 51 '') and it was inserted during the reverse transport on the back of a sheet If there were an obstacle (for example an envelope flap), the edge of the sheet P could be held on the rib edge 51 a '' during a reverse transport, a spacing error would occur and an incorrect printing process would take place. That is, the required line spacing would be destroyed in the reverse transport and in the amount of sheets immediately afterwards transported in a forward direction.

To overcome this problem, the ribs 51 preferably have a substantially trapezoidal shape when viewed from the side. Therefore, even in the case of an obstacle such as a flap part of an envelope, the trapezoidal shape of the ribs reduces any sticking during a reverse transport operation, and consequently there are no distance errors and reliable sheet feeding is ensured.

Second, the leading edge Pf may bend when printing is performed near the leading edge Pf of the sheet P. However, if the ribs 51 '' are not trapezoidal (as in Fig. 17 (a), rib 51 ''), the leading edge Pf of the sheet may rest on the top of the ribs 51 '' leading to the pairs of output rollers 71 and 72 . The sheet P is raised in the area of the print head 60 , and the likelihood of ink smearing on the print head 60 increases.

Since the ribs 51 have viewed from the side substantially trapezoidal shape to overcome this problem, in the present embodiment (as shown in Fig. 17 (b)), the leading edge moves Pf of the sheet P rapidly from the top surface 51 a away , and the appearance of sheet floating is thus reduced, and the likelihood of ink smearing on the printhead 60 is greatly reduced.

In addition, the regulating element 50 comprises a guide portion 51 e ( FIG. 4) attached thereto for guiding the leading edge of the sheet P to the pairs of output rollers 71 and 72 . The guide section 51 e is preferably arranged upstream of the discharge rollers 71 and 72 and downstream of the ribs 51 (in relation to a forward sheet transport direction). As a result, even if the ribs 51 were not substantially trapezoidal, the leading edge of the sheet P can be guided to the output roller pairs 71 and 72 more reliably. Thus, by the guide portion 51 is provided e in the sheet transport direction upstream of the discharge roller pairs 71 and 72 and the guide portion preferably 51 e is provided at any other point, out the front edge of the sheet P reliably to the output roller pairs 71 and 72 and a piercing the Sheet P to the print head 60 and smearing it prevented more reliably.

Moreover, when a plurality of ink colors are discharged from the print head 60 and color printing is performed, ink dots are formed over previously formed ink dots, and the curl of the sheet can become particularly strong. However, due to the advantageous construction disclosed above, the likelihood of the curled sheet P bumping against the printhead 60 and smearing of ink is considerably reduced.

It is again to FIG. 5, 19 and 20 referred to. The holder 19 a is mounted within the output section 120 and is rotatably held there. The holder 19 a includes the guide sheet 19 b and the toothed roller 19 which is rotatably mounted in the holder 19 a. In addition, the first support element 81 and the second support element 91 each comprise inclined surfaces 81 d and 92 (see FIG. 2). The first support element 81 is located in the area B2 and thus in the upright position. When a sheet P is discharged to the size A4 by the discharge roller pairs 71 and 72, the leading edge Pf will encounter b to the leader sheet nineteenth The force of the sheet P against the sheet 19 b cause the holder 19 a rotates in the by the arrow Y (Fig. 5) in the direction indicated. The leading edge Pf of the sheet P is, however b driven downward and directed by the toothed roller 19 through the output section 120 of the guide sheet nineteenth

At the same time, both side areas of the sheet leading edge Pf are supported by the inclined surfaces 81 d of the support portion 81 and the roller portion 91 a of the drive roller 91 from below. When the sheet P is fed in the sheet transport direction, the edge supported by the drive roller 91 is steered upward from the support portion 92 while being driven by the roller portion 91 a. As a result, the leading edge Pf is driven into a hollow concave shape as the sheet is gradually discharged, as shown in Figs .

Fig. 19 shows the exiting sheet P while it is in engagement with the inclined surface 81 d, the roller portion 91 a and the toothed roller 19 . Since the sheet P is forced into a hollow, concave shape, the sheet is seen stiff in the discharge direction and is fed in an apparently floating state in the discharge direction. Therefore, the time until the discharged sheet P slidably contacts a printed surface P1a of a previously printed and issued stacked sheet P1 is delayed. This delay allows the ink of the already printed sheet P1 enough time to dry.

When the sheet P is further transported in a sheet discharge direction, its rear edge passes through the output roller pairs 71 and 72 . The sheet P therefore loses its transport force, and the rear part of the sheet is held in its concave state by means of the discharge section 120 and in particular by the support section 81 and the drive roller 91 , which gives ordinary sheets a low driving force.

When a subsequent sheet P2 is printed, its leading edge P2f passes the discharge roller pairs 71 and 72 as shown in FIG. 20. The previous sheet P held by the discharge section 120 is released when its rear edge Pb is touched by the leading edge P2f of the following sheet P2. When the previous sheet P held by the discharge section 120 is released, it is stacked on a previous sheet already printed (P1 in Fig. 19). However, due to the advantageous construction of the discharge section 120 , the time until the sheet P contacts the sheet P1 is further delayed, and enough time has passed to allow the ink on sheet P1 to dry. The concavity of the sheet P enables P2 to touch the back edge Pb of sheet P easily and reliably. If the sheet P had no concavity, it would be very difficult to ensure that the leading edge P2f touches the trailing edge Pb of the sheet P.

After the leading edge P2f of sheet P2 has touched the trailing edge Pb of sheet P and the contact of sheet P to the supporting portion 81, the roller portion has been solved 91a and the toothed roller 19, the forward comes transport of sheet P2 temporary halt . This stopping process can be accomplished by counting pulses from the motor (not shown) that drives the output roller pairs 71 and 72 . When the desired number of pulses has reached the predetermined number, the motor drive mechanism can be restarted and the sheet P2 can be further advanced through the output section 120 . By introducing an ejection method which includes temporarily stopping the further output of P2 while sheet P is stacked on previously printed sheets, and in which the leading edge P2f of sheet P2 contacts the rear edge Pb of sheet P when it contacts the sheet P is in a concave state, the leading edge P2f of the following sheet P2 and the rear edge Pb of the previous sheet P can reliably engage with each other, and the sheet stacking process (ejection process) from sheet P onto the previous, already printed sheet P1 ( see Fig. 19) very reliably. Without the process of temporarily stopping sheet P2, the reliability of the stacking process is reduced and it is less easy to ensure that the ink has enough time to dry.

If relatively stiff sheets of size B5 or smaller, such as envelopes, are used, as shown in Fig. 21, the curved state of a relatively flexible sheet is not d by its support to the pair of upwardly inclined supporting surface 81 and to drive roller 91 reached because the stiffness of the sheet prevents it from adopting a concave figuration. To a precise sheet feeding to ensure, when the relatively stiff sheet PE is led from the supporting surface 81 d, the pressing force of the coil spring 73 and the pressure contact force against the discharge rollers 71 may be reinforced in order to increase the force is outputted with which sheet P. However, traces of ink may form on the surface of sheet P if the compressive force of the coil spring 73 is increased too much, thereby reducing the quality of the print. Such traces are particularly undesirable where glossy leaves are used because they appear more clearly.

In order to overcome this problem, the downward force exerted by the holder 19 a on the sheet P is increased, and the weight which acts on the sheet P in contact with the roller section 91 a of the drive roller 91 is caused by the Dead weight of the sheet increased. Thus, a larger driving force is available from the drive roller 91 onto the sheet to be discharged compared to the above-mentioned ordinary sheets.

Furthermore, as shown in Fig. 21, when the first support member 81 of the left support assembly 80 is manually shifted to the lying position, the second support member 82 is exposed and supports the exiting sheet P. When the rigid sheet PE is removed from the first Support element 81 would be supported and guided, a resistance would build up between the surface 81 d and the blade, since the surface 81 d is inclined upwards and is in a relatively high position. Thus, to avoid this situation, the second support member 82 is used to support the sheet since it does not or only lightly touch the sheet P, and the drive roller 91 is used to support and drive the sheet.

In this configuration, the sheet PE is output by the output roller pairs 71 and 72 and is held by the output roller pairs 71 and 72 , the roller portion 91 a and the stiffness of the blade PE in a substantially horizontal state (floating state) until the rear Edge of the sheet PE passes through the output roller pairs 71 and 72 . Thus, the discharge of the sheet PE and its subsequent stacking on the previously discharged sheet PE1 is delayed to allow the ink time to dry on the printing side PE1a of the sheet.

If the sheet PE is transported further and the rear edge PEr of the sheet PE passes between the output roller pairs 71 and 72 , the transport force is lost. As shown in Fig. 22, a side of the rear edge portion PEC is the leaf PE of the driving force of the roller portion a conveyed 91, as shown by the arrow c1, and slides of the same the other side of the downwardly directed support surface 82 a of the second supporting member 82 as shown by arrow c2. In this way, the sheet PE is stacked on a previously printed sheet PE1 (see Fig. 21).

Although the above-mentioned output function is available when the first support element 81 of the support section 80 is manually brought into a lying position, it is not always practical or desirable for the user to manually position the first support element 81 . Thus, when printing ordinary sheets of A4 size or B5, the edge will guide pushed 23 to the right, and the lower pin 81g of the first support member 81 abuts, as set forth above, b to the third or the second plate 59, and the first supporting element 81 automatically assumes an upright position. According to this embodiment of the invention, sheets can be output due to the presence of the drive roller 91 even when the first support member 81 is in its upright position.

As shown in Figs. 23 (a) 1 and 23 (a) 2, the leading edge PEf of the sheet PE is discharged from the output roller pairs 71 and 72 (rollers 72 not shown) so that the center point is in the direction of the sheet width of the sheet PE during the transport of the sheet PE exerts an upward force on the holder 19 a and the front edge PEf of the sheet PE is pressed down by the holder 19 a. At the same time, both side areas of the front edge PEf of the sheet PE are supported from below by the first support element 81 and the roller section 91 a of the drive roller 91 . The supported by the drive roller 91 side portion of the sheet PE is conveyed forward by the rollers of the sections 91 a to the sheet of PE applied force. Thus, as shown in Fig. 23 (a) 2, the sheet PE is slowly discharged by simultaneously forcing the printed side into a concave shape when the sheet PE is viewed from the sheet discharging direction.

Thus the output of the sheet PE is delayed long enough so that the ink printed on the previous sheet PE1 dries before the sheet PH against the already issued and stacked sheet PE1 and the printed surface PE1a rubs.

If the sheet PE is transported further and the rear edge of the sheet PE passes between the output roller pairs 71 and 72 , the transport force provided by the output roller pairs is lost. While, as shown in Fig. 23 (b) 1 and 23 (b) 2, a corner PER2 the rear edge of the sheet PE remains supported by the first support member 81, is the other corner Per1 the rear edge PEr of the leaf PE of the drive roller 91 continues until the sheet PE loses contact with the roller portion 91 a. As a result, the rear edge portion PEr of the sheet remains in an oblique position as shown in Fig. 23 (b) 2.

While the sheet PE is in this position, characters are printed on the subsequent sheet PE2. As shown in Figs. 23 (c) 1 and 23 (c) 2, when the leading edge PE2f of the sheet PE2 passes through the pairs of rollers 71 and 72 , it abuts the rear edge PEr of the preceding sheet PE and pushes the sheet PE so that the sheet PE is stacked on the previous printed sheet PE1 of the sheet storage bin 18 as shown in Figs. 23 (d) 1 and 23 (d) 2.

For example, if printing on small envelopes or postcards is desired and the edge guide 23 , as shown in Fig. 2, near the side plate 16 'of the subframe 16 , which forms the second and opposite edge guide, the edge guide 23 can be arranged be pushed from their extreme left position to the position shown in dashed lines. Here, the left support arrangement 80 passes the changeover switch 59 , and the first support element 81 automatically assumes a lying position, as a result of which the second support element 82 is exposed. Since the sheet PH is rigid when the sheet PH of the discharge roller pairs 71 and 72 is outputted, the sheet PH, as shown in Fig. 24 is shown, transfer roll pairs in a substantially horizontal state (floating state) of the off 71 and 72 output until its rear edge passes through the output roller pairs 71 and 72 . Since the second support element 82 is located under the sheet PH and at this time either does not touch the sheet PH or only touches it slightly, the sheet PH experiences little resistance to sheets to be dispensed.

When the sheet is fed and the rear edge of the sheet PH passes through the output roller pairs 71 and 72 , the driving force is lost. At this point, as shown in FIG. 25, one side of the rear edge region PHc a advantage of the sheet by the force of the roller portion 91 in the direction indicated by the arrow c1 direction of transportation and the other side of the sheet PH slides down descending support surface 82 a of the second support element 82 , as shown by arrow c2 of FIG. 25. In this way, the sheet PH is stacked on the previously printed sheet PH1 (see Fig. 24) such that the time it takes for the sheet PH to match the printed side PH1a of the previous sheet PH1 already discharged and stacked on the sheet discharge tray coming into sliding contact is delayed to ensure that the ink has enough time to dry on the printed sheet PH1.

As stated above, the printhead is the one described corresponding to the first embodiment of the invention Inkjet printer operated to mark characters on the surface a sheet of paper that is then output while both side areas of the sheet of a pair of Support sections are supported. Since a drive roller for  Use as one of the support sections of the Support pair has been provided, the sheet is through the force exerted by the drive roller is output. Therefore even relatively stiff leaves are quickly applied without loss Feed accuracy output, although the pair of support sections is arranged in a position which is relatively higher than that leaking leaves.

In Fig. 26 (a) and 26 (b) of the main part of a second embodiment of the invention is shown. In the discussion of this embodiment, the same components are denoted by the same reference numerals, and a detailed description of these components is therefore omitted. The sheet discharge section 130 of the unit of the second embodiment is different in construction from the first embodiment.

The sheet discharge section 06055 00070 552 001000280000000200012000285910594400040 0002019621071 00004 05936 cut 130 includes a pair of support sections 180 for supporting both side portions of the sheet P to be discharged from below and a toothed roller (not shown in Fig. 26) similar to the toothed roller 19 according to the first embodiment. The support portion 180 is a driven roller that is rotatable by contact with the sheet P. Although a pair of driven rollers 180 are mounted so that both side portions of a sheet to be discharged are supported from below, only one of them is shown in FIG .

The driven roller 180 is rotatably supported by a shaft 181 which is rotatably supported by a support member 152 c. The support element 152 c is formed in one piece with a base section 52 b, which in turn is formed in one piece with the regulating element 50 . The driven roller 180 is held so that it is rotated by a weak force.

The guide plate 182 differs functionally from the prior art corresponding support element 612 , which, as shown in Fig. 27, is mounted on both sides, since it serves to guide the leading edge of the sheet P to the driven roller 181 . Therefore, the guide plate 182 is located at a relatively low height, lower than the height indicated by the line t1 connecting the top of the output roller 71 and the driven roller 180 . The sheet P experiences very little resistance from the guide plate 182 .

The driven roller 180 is arranged in the direction of the sheet width in relation to the outermost roller 72 '. In the printer shown in Fig. 27, which corresponds to the prior art, the support surface 612 a is arranged so that it is (on a line extended in the sheet transport direction) at the same position as the toothed roller 682 . Thus, when the support surface 612 a touches the side portion of the surface of sheet P, the side edge Pe of the sheet P becomes dirty because it is driven upward and consequently brought into contact with the print head 660 .

On the other hand, according to the present embodiment of the invention, the side portion of the sheet P is held down by the toothed roller 72 'since the driven roller 180 is disposed inward with respect to the toothed roller 72 ' to support the sheet in the sheet width direction from below. As a result, the side edge Pe is prevented from coming into contact with the print head 60 and thereby becoming dirty.

As far as the output unit 136 is concerned, it basically works in the same way as the output unit 601 corresponding to the prior art. However, the provision of the pair of driven rollers 180 in place of the prior art support members 612 mounted on both sides substantially reduces the friction experienced by the sheet P. Because of this advantage, even relatively stiff sheets are dispensed quickly without sacrificing feed accuracy, although the pair of driven rollers 180 are located in a position that is relatively higher than the exiting sheets. Moreover, no ink traces left by the toothed rollers 71 remain clearly visible on the sheet P since an increase in the pressure contact force of the sheet discharge rollers 72 is not required, and deterioration in print quality is prevented.

The above is an explanation of the embodiments of this invention, but the present invention is not limited to the above-described embodiments. That is, variations are possible within the scope of the invention. For example, the support portion 80 in the first embodiment may be provided similarly to the support portion 90 so that it includes a drive roller 91 and a guide plate 92 . In addition, the roller of the support section 80 can be exchanged for a driven roller in order to enable rapid sheet discharge. Even if the roller of the support section 80 is a driven roller, rapid sheet output can also be achieved since the resistance to the emerging sheet is greatly reduced compared to the support element 81 . In addition, the drive roller 91 can be further improved by the roller portion 91 a of the drive roller 91 is equipped with a toothed roller such as the sheet discharge roller 72 , so that the emerging sheet is prevented from contacting the print head.

It is therefore clear that the aspects mentioned above, including those from the previous description lichen, can be achieved efficiently, and since the above Construction certain changes can be made  without departing from the spirit and scope of the invention all contained in the above description and in the enclosed drawings illustrated matter as explanatory and not to be interpreted in a restrictive sense.

It is also understood that the following claims all generic and distinctive features of the herein described invention and all information on the scope of Invention to include, which fall due to language could.

Claims (8)

1. Sheet output device for a printer with a Printer body, wherein the output device is a first support assembly attached to the printer body and a second attached to the printer body and from the first support arrangement spaced support arrangement has, wherein the first support arrangement a first bottom area one from the printer body from given sheet and the second support assembly one supports the second underside area of the sheet, and wherein at least the first support arrangement is a roller includes. 2. Sheet dispenser according to claim 1, wherein the Roll a drive roller for conveying the sheet from the sheet dispenser. 3. Sheet dispenser according to claim 1 or 2, wherein the roller is a driven roller which is driven by the Contact with an exiting leaf is driven in this way is that the emerging sheet from the Sheet discharge device is conveyed. 4. Sheet dispenser according to one of the preceding Claims, wherein the first support arrangement Drive roller for conveying the sheet from the Sheet dispenser and the second support assembly has a driven roller through the contact is driven with an emerging blade in such a way that the emerging sheet from the Sheet discharge device is conveyed. 5. Sheet dispenser according to one of the preceding Claims, wherein the first support assembly and the second  Support arrangement a drive roller for transportation of the sheet from the sheet dispenser. 6. Sheet dispenser according to one of the preceding Claims, wherein the first support assembly and the second Support assembly include a driven roller that through contact with an emerging sheet like this is driven that the emerging sheet from the Sheet discharge device is conveyed. 7. Sheet dispenser according to one of the preceding claims, further comprising:
a frame;
first and second transmission shafts rotatably supported by the frame;
a first gear arranged on the first transmission shaft and a second gear arranged on the second transmission shaft;
at least one feed roller shaft rotatably supported by the frame;
at least one feed roller gear arranged on and rotating with the feed roller shaft;
at least one sheet output shaft rotatably supported by the frame;
at least one sheet discharge roller gear arranged on and rotating with the sheet discharge shaft;
a roller shaft rotatably supported by the frame; and or
a roller gear arranged on and rotating with the roller shaft, the drive roller including a roller portion rotating with the roller shaft;
wherein the first gear arranged on the first transmission shaft is functionally connected to the at least one feed roller gear and the at least one sheet discharge roller gear and the second gear arranged on the second transmission shaft is functionally connected to the at least one sheet output roller gear and the roller section gear so that when the sheet feed roller shaft is in the sheet transport direction is rotated, the sheet discharge roller shaft and the roller shaft also rotate in the sheet transport direction. 8. Sheet dispenser according to one of the preceding Claims, the printer further comprising at least one Output roller comprises, and wherein at least one of the Support arrangements offset in the paper feed direction to the at least one output roller is arranged.