JPH01261131A - Sheet separating mechanism for sheet feeder - Google Patents

Abstract

PURPOSE:To provide separability in quick response to the sort of sheet by furnishing a separating pawl capable of advancing and retracting inside a sheet guide, detaining normal sheets with this pawl at the bottom corner, and retracting the pawl for thicker sheets. CONSTITUTION:In the case of thin sheets, they H1 slide on a slope 12 and can not move a separating pawl 20, and only one at the top will buckle and get over the pawl 20 to be forwarded to the printer body. In the case of stiff sheets, accommodation is made upon adjusting the position of a hopper so as to be in agreement with the cross width of the sheets H2, and when the printer is turned on, the sheet is pulled out downward by sheet feed rollers 5, 5. Therein the stiffness of the sheet H2 overwhelms the resilient force of the separating pawl to cause generation of a force to rotate the pawl 20 ahead, and a gap to allow passage of one sheet is formed between the pawl 20 and slope 12, so that each sheet H2 which has slided on the slope 12 passes through this gap to proceed downward. Thus the sheet H2 will be set in the printer without being buckled by the pawl 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a cut sheet separation mechanism that can handle multiple types of printing paper having different paper thicknesses.

(Prior art) When printing on cut sheets, so-called cut sheets, using a serial printer, in order to save the trouble of feeding paper,
A paper feeding device M is provided with separating claws for securing the corners of the paper at the lower both ends of the front of the paper storage unit, and the paper pulling force from the rollers is applied to the paper on the front side to separate the paper on the front side. Only the pieces are buckled with a separating claw and taken out one by one.

However, if the print carrier itself is strong, such as a card or an envelope, the separating claw cannot fully buckle it, so it is necessary to separate it using a slope formed on the lower front surface. For this reason, when printing on stiff carriers such as cards, an attachment is usually installed on the paper feeder to position both edges of the paper closer to the center than the separating claws.
It is necessary to prevent the paper from coming into contact with the separation claws.

For this reason, there is a problem in that it is necessary to attach and detach the attachment depending on the type of printing paper.

(Objective) The present invention has been made in view of the above-mentioned problems, and its object is to provide a paper separation mechanism that can quickly respond to different types of paper.

(Summary of the Invention) That is, the present invention is characterized in that a separation claw that can move back and forth is provided at a position that abuts the bottom corner of the sheet.

(Example) The details of the present invention will be described below based on illustrated examples.

FIG. 1 shows a paper guide device M to which the present invention is applied, and reference numeral 1 in the figure denotes a frame body that engages with the blink body through claws 2.2 and is folded onto the surface of the printer body. It is provided with a drive gear 3 that engages with a platen gear G fixed to the shaft of the platen P when set in the printer, and a paper feed roller 5.5, which will be described later, that engages with the platen gear G via a gear train mechanism 4.
and a hopper member 6.6. This hopper member 6
．． 6 is mounted so as to be axially movable along a guide shaft 9.9 parallel to the platen P.

FIG. 2 shows an enlarged view of one of the above-mentioned hopper members (the one on the left in FIG. A receiving plate 11 supporting the lower end of H is horizontally fixed on the inner side. A slope 12 that slopes forward and downward is provided at the tip end of the receiving plate 11 on the paper feed roller side, and a guide don 15 is provided on the force detection side of the space formed by the side wall member 10 and the receiving plate 11. A paper pressure plate 19 is provided which is guided substantially perpendicularly to the paper H by a groove 16 and is always urged toward the paper feed roller 5.5 by a compression spring 17.

20 is a separation claw characterized by the present invention, and No. 3.4
As shown in the figure, the paper H is arranged at a position where the lower corner of the paper H comes into contact with it, is rotatably attached to a shaft 21 parallel to the guide shaft 9, and is supported by an elastic member 22 (Fig. 4).
It is constantly biased toward the side and does not rotate when the stiffness of normal printing paper is strong, and when it comes to stiff media such as postcards, it moves forward (in the direction of the arrow in the figure) as the medium moves. ), the elastic force is set so that it rotates.

In this embodiment, when printing on normal printing paper, the position of the side plate 10 is adjusted so that the inner surface thereof comes into contact with the side of the paper, and the printing paper is set in the storage path.

When the printer main body is operated after such preparation is completed, the rotation of the platen P is transmitted to the paper feed roller 5.5 via the wheel train 3.4, and the paper Ht on the front side is moved downward. In this process, the feeding force FO1 of the paper H1 by the paper feed roller 5.5, the angle θ of the slope 12 with respect to the plane perpendicular to the paper H1, the friction coefficient U of the slope 12, the separation claw 2,
Assuming that the presser foot pressure Ft for the paper is zero and the buckling load f of the paper is, if the paper is thin, that is, Fo>f, then u −f−sin θ < Ft−CO8θ
Then, as shown in Figure 5, paper H! The paper slides on the inclined surface 12 and cannot move the separation claw 20, and only one of the sheets on the surface buckles, climbs over the separation claw 20, and is sent to the printer main body. Thereafter, the above-described process is repeated to automatically replenish printing paper.

On the other hand, when printing on a stiff medium such as a postcard or an envelope, the position of the hopper member 6.6 is adjusted to match the width of the medium H4 to be printed, and the medium H2 is moved to the hopper member 6.6. 6. When the printer is operated in this state, the medium is drawn downward by the feed roller 5.5 rotated by the platen. At this time, since the paper is thick, FO<f, and μmfo-sinθ > Ft-cO3θ,
Since the stiffness of the print medium H1 is greater than the elastic force of the separating claw, a force sufficient to rotate the separating claw 20 forward as shown in FIG. 6 is generated. As a result, a gap sufficient for one medium to pass through is formed between the separating claw 20 and the slope 12, so the medium H□ that has slipped on the slope 12 passes through this gap. Move downward. As a result, the medium H is moved downward from the storage path and set in the printer without being buckled by the separation claw 20.

In this embodiment, the separation claw can be retracted by rotating around the axis, but at least the separation claw 2
A part of the fixed side of 0 is formed by an elastic member, and while the elastic force of the elastic member makes it impossible to rotate due to the stiffness of normal paper, the print medium contacting part can rotate forward due to the stiffness of thick paper such as postcards. It is clear that similar effects can be achieved by selecting the option to do so.

FIG. 7 shows a second embodiment of the present invention, in which reference numeral 30 denotes a separating claw 30 provided below the side wall of the hopper section 6.6, which is attached to an axis 31 parallel to the plane of the paper. The thick media 1
It is configured to be movable to two positions (positions indicated by dashed lines - in the figure) that form a gap between it and the slope 12 that is sufficient for the passage of the sheet.

In this embodiment, when printing on normal printing paper, the lever 32 is used to move it toward the pressure plate 19 (in the figure,
When the paper is set in the storage path and the printer is operated, the paper is pulled downward by the paper feed roller 5.5, and the lower end corner of the paper is buckled by the separation claw 30. is transferred to the printer.

On the other hand, when printing on stiff media such as postcards or envelopes, the lever 31 moves the separating claw 30 forward to remove it from the paper path (the position shown by the dotted chain line in the figure). When the printer is operated in this state, the paper feed roller 5
．． 5, the medium on the surface is pulled downward. In this case, since there is a gap between the separation claw 30 and the tip of the slope 12, the medium H2 is not stopped by the separation claw 30.
It will slide down the slope 12 and be transferred to the printer.

(Effects) As described above, according to the present invention, a separating claw that can move forward and backward is provided inside the paper guide section of the main body, and in the case of regular paper, the bottom corner of the paper is locked to the separating claw, and In the case of thick media, it is retracted to a position sufficient to pass one sheet, so various types of media can be reliably transferred to the blink without the need for special attachment members. Not only is this possible, but it is also possible to speed up and simplify paper switching.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the paper guide mechanism to which the paper separation mechanism of the present invention is applied, Fig. 2 is a sectional view of the hopper section in the drawing of Fig. 1, and Figs. A perspective view and a side view showing one embodiment of the separation mechanism of the present invention, FIGS. 5 and 6 are explanatory diagrams showing the operation of the same device, respectively, and FIG. 7 is a side view showing another embodiment of the present invention. It is a diagram. 1... Frame 3... Drive gear 5.
...Paper feed roller 6...Hopper member 7...
... Width regulation member 1o ... Side wall member 12 ...
・・Support plate 12a・・Slope 20・・・・
Separation claw 19...Press plate H...Paper
P... Platen applicant Seiko Epson Co., Ltd. Orient Watch Co., Ltd. Agent Patent attorney Keiji Nishikawa Katsuhiko Kimura Figure 1 Figure 6

Claims (3)

[Claims] (1) A pair of hopper members consisting of a side wall section that regulates the width direction of the stacked print media, a receiving plate section that regulates the lower surface, a pressure plate section that presses the back surface of the paper forward, and a front side of the paper. The paper separating mechanism is provided with a paper feed roller that contacts the paper feed roller and pulls the paper downward, and a separating slope formed to be inclined downward in front of the receiving plate. , a paper separation mechanism in a paper feeder comprising a claw member configured to move forward and backward according to the thickness of the paper. (2) The paper separation mechanism in the paper feeding device according to claim 1, wherein the separation claw is pressed toward the pressure plate portion by a spring member. (3) The paper separation mechanism in the paper feeding device according to claim 1, wherein the separation claw is mounted so as to be movable in a direction substantially perpendicular to the paper surface by external operation.