JP3346461B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder applied to an apparatus such as a printer.

[0002]

2. Description of the Related Art Positioning a stack of recording paper below a recording / writing section has been widely adopted as a means for reducing the space occupied by the apparatus. Due to the fact that the path must be formed in a U-shape, if there is a step at the junction of the paper guide or at the junction of the paper transport path, when thick recording paper passes through these parts, The strong stiffness of the paper causes a repulsion sound, or the strong stiffness causes an inconvenience such as a forward pushing force which adversely affects printing.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a paper feeder having such a U-shaped conveyance path, which is a new type of paper feeder which can eliminate the above-mentioned inconveniences which occur at the connecting portion and the flow-in point. An object of the present invention is to provide a paper feeding device.

[0004]

That is, in order to achieve the above object, the present invention provides a reversing paper feed roller which joins a paper transport path below a flat paper transport path leading to a recording / writing section. In a paper feeding device having a reversing paper transport path provided with a guide member having an inner surface serving as a guide surface along a reversing paper feed roller, a position constituting the reversing paper transport path, The guide member is moved from the position that constitutes the reverse paper transport path to the position that connects to the flat paper transport path in conjunction with the recording and writing operation, while being displaceably provided at a position where it is smoothly connected to the paper transport path. A cam member is provided.

[0005]

Embodiments of the present invention will be described below. The drawings show an embodiment of the present invention applied to an ink jet printer.

First, a schematic configuration will be described with reference to FIG. 4 showing the entire contents of a printer. Below the ink jet type recording / writing section denoted by reference numeral 1, different sizes or different types of recording paper are fed. Paper feed units 2U and 2L are arranged in a tiered manner, and hoppers 3U and 3L containing respective recording papers are removably provided therein, and upper hopper 3U is provided by an upper pickup roller 4U. The recording paper pulled out from the inside is recorded via the sub-paper feed roller 5, and the recording paper pulled out from the lower hopper 3L by the lower pickup roller 4L is recorded via the U-shaped paper guide 7, respectively. The paper is fed to a flat paper transport path 8 extending to a main paper feed roller 9 provided in the writing section 1.

For this reason, on the front side of the upper paper feed unit 2U, that is, on the right side of the drawing, the sub paper feed rollers 5 and the rollers 6 rolling in contact with them are provided on the upper side of the flat paper transport path 8 in the paper transport direction. A U-shaped paper guide 7 is formed at the nip portion A so as to join the nip portion A. Further, at the junction of the sub-paper feed roller 5 and the U-shaped paper guide 7, , Guide surface 2 along the sub paper feed roller 5 on the inside
A substantially triangular movable guide member 20 whose outer surface 20a forms a part of the U-shaped paper guide 7 is rotatably mounted around a support shaft 20c as described later.

In the drawing, reference numeral 10 denotes a case main body that covers the recording / writing section 1 and the upper paper feed unit 2U. The case main body 1 has a hinge provided on the front side thereof and a hinge provided at the lower end of the upper paper feed unit 2U. A front door 12 that can be opened at right angles to the right side of FIG.
The arcuate guide surface 13 provided on the inner surface of the front door 12 is aligned with the lower half of the U-shaped paper guide 7 provided on the upper paper feed unit 2U side and the outer surface 20b of the movable guide member 20, thereby lowering the lower surface. Of the paper guide route.

The front door 12 has a manual guide surface 14 extending horizontally toward the nip portion A between the sub-paper feed roller 5 and the roller 6 at the upper end of the guide surface 13 along the outer surface 20b of the movable guide member 20. Is formed outward, and a hinge 15 is provided on the upper part of the front door 12 at substantially the same position as the manual guide surface 14. The guide plate 16 is provided to be openable and closable so that it can be opened horizontally to the front side. Reference numeral 18 in the drawing denotes a pinch roller that rolls in contact with the peripheral surface of the sub-paper feed roller 5.

FIGS. 1 and 2 show a movable guide provided at this portion in order to suppress the occurrence of paper flipping noise and jamming at the junction B between two paper feeding paths in the upper paper transporting path. A mechanism for displacing the member 20 before and after printing is shown. The movable guide member 20 has one end fixed to one point on the frame and the other end fixed to one point on the movable guide member 20 as shown in FIG. The second stable spring 22 is stably held at the position C which forms the upper paper transport path by the urging force of the two stable springs 22. Normally, the first paper which forms the reverse paper transport path by the roller release cam 24 via the cam follower 23.
And a second position D at which the inner guide surface 20a is smoothly connected to the flat paper transport path 8, and if a paper jam occurs in this portion, the neutral point Is configured to be stably displaced to the position E where the paper jam is processed by the two-stable spring 22 exceeding.

On the other hand, the roller release cam 24 is a roller which is driven by the same drive motor as the pickup roller 4 and meshes with a rotating gear 25 to rotate forward and backward for each sheet feed. The first cam surface 24a and the first cam surface 24a are operated so that the pinch roller 18 and the roller 6 are brought into contact with the peripheral surface of the sub paper feed roller 5 at the initial stage of paper feeding, and are separated from the peripheral surface of the sub paper feed roller 5 at the time of printing. 2 cam surface 24b is provided, and a cam that opens like a trumpet for displacing the movable guide member 20 to the above-described first position C and second position D in accordance with these timings. Groove 2
4c is provided.

On the other hand, the above-mentioned cam follower 23 rotates around the support shaft 21c in a state where the roller 23a provided at the tip thereof is engaged with the cam groove 24a of the roller release cam 24, and the movement is changed by the pin 20d. The movable guide 20 is configured to be transmitted to the movable guide 20 via the movable guide 20.

In the paper feeder constructed as described above, the roller release cam 24 driven by the gear 25 interlocked with the pickup roller 4 during normal paper feeding.
Rotate in the direction of the arrow shown in FIG. 1, that is, in the clockwise direction in FIG. 1, to release the push-up of the pinch roller 18 by the first cam surface 24a and to rotate the roller 6 by the second cam surface 24b.
Are lifted and pressed against the peripheral surface of the sub-paper feed roller 5, and the cam follower 23 is rotated counterclockwise in the figure by the cam groove 24c via the roller 23a engaged therewith. The movable guide member 20 is moved to the paper feed position C via the pins 20d, that is, the guide surface 20a on the inner surface thereof is made to follow the peripheral surface of the sub-paper feed roller 5, and is made to follow the outer surface 20b and the arc-shaped guide surface 13. To form the upper and lower paper transport paths.

As a result, the recording paper pulled out from the hopper 3 by the pickup roller 4 reaches the nip portion between the sub paper feed roller 5 and the pinch roller 18, and is rotated by the output signal from the paper end detection sensor. 5 feeds out onto a flat transport path 8.

As described above, when the recording paper is fed to the main paper feed roller 9, the driving force to the sub paper feed roller 5 is cut off by a detection signal from a cue detection sensor (not shown), and at the same time, As shown in FIG. 2, the pinch roller 18 and the roller 6 are separated from the peripheral surface of the sub-paper feed roller 5 by the first and second cam surfaces 24a and 24b of the inverted roller release cam 24. The cam follower 23 rotates clockwise in the figure toward the wide opening of the cam groove 24c by the biasing force of the bi-stable spring 22 of the movable guide member 20, and rotates clockwise in the figure via the pin 20d. And the outer surface 20b is brought into contact with the arcuate guide surface 13 and the inner guide surface 20a is displaced to a position D where the inner surface guide surface 20a is smoothly connected to the flat paper transport path 8 so as to reach the junction B. Eliminate that step.

As a result, the recording paper is prevented from being fed by the pinch roller 4 and being pressed by the pinch roller 18 and the roller 6, that is, the paper feed resistance, and is further flattened while being freely fed by the sub paper feed roller 5. The paper is fed to the recording head while the feed amount is correctly controlled by the main paper feed roller 9 on the paper transport path 8.

Further, when the recording paper reaches the confluence point B where the recording paper moves from the curved paper conveyance path to the flat paper conveyance path 8, the step is eliminated by the displacement of the movable guide member 20. When the end comes out of the inner guide surface 20 a of the movable guide member 20, the arc-shaped guide surface 13 is formed.
Does not make a popping sound, and also reduces the paper stiffness pushing forward during the transition from a curved road to a straight road, and also suppresses paper jams in this area. Thus, a more accurate and clearer recorded image is written.

When a paper jam occurs at the junction B, as shown in FIG. 1, the front door 12 is opened and the movable guide member 20 is rotated clockwise in FIG. If
The movable guide member 20 is held at the position E by the bi-stable spring, so that a necessary jam clearance can be easily performed.

[0019]

As described above, according to the present invention, a movable guide member is provided at the junction of a flat paper transport path following a recording / writing section and a reverse paper transport path provided below the flat paper transport path.
This is linked with recording and writing, so that the inner guide surface is smoothly connected to the flat paper transport path, so that the transition of the trailing end of the recording paper from the curved path to the flat path is moderated, and this transition is performed. The temporary pushing force of the recording paper caused by the stiffness in the process in the forward direction can be reduced, and the adverse effect on the printing accuracy can be eliminated as much as possible.

Further, by eliminating the step at the boundary of the paper transport path, it is possible to generate a repelling sound generated when the rear end of the recording paper transported in a bent state suddenly returns to the flat road side. As much as possible, the recording / writing operation can be made quieter, and the occurrence of paper jam at the step can be suppressed.

Further, since a bi-stable spring is acted on the movable guide member, a position for forming a reversing paper transport path, a position for connecting the inner surface to a flat paper transport path smoothly, and a processing for paper jam. This makes it possible to realize the movement displacement to the position to be performed by one member, thereby simplifying the apparatus.

[Brief description of the drawings]

FIG. 1 is a side view showing a main part of a paper feeding device according to an embodiment of the present invention in a state in which paper is initially fed.

FIG. 2 is a side view of a main part of the same device showing a state at the time of recording and writing.

FIG. 3 is a side view of a movable guide member.

FIG. 4 is a diagram showing the entire configuration of a printer including the above device.

[Explanation of symbols]

 Reference Signs List 4 pickup roller 5 sub-paper feed roller 8 flat paper conveyance path 20 movable guide member 22 2 stable spring 23 cam follower 24 roller release cam 24c cam groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 5/26 B41J 13/10 B65H 5/38

Claims (3)

(57) [Claims] 1. A paper feeder having a reversing paper transport path provided with a reversing paper transport roller which joins the paper transport path below a flat paper transport path leading to a recording / writing section, wherein: A guide member having an inner surface serving as a guide surface along the reversing paper feed roller can be displaced between a position forming the reversing paper transport path and a position for smoothly connecting the guide surface to the flat paper transport path. Along with
A paper feed device, further comprising a cam member for moving the guide member from a position configuring the reverse paper transport path to a position connecting to the flat paper transport path in conjunction with a recording / writing operation. 2. The paper feeding device according to claim 1, wherein the cam member is provided with a portion for separating a driven roller that rolls in contact with the reversing paper feeding roller during a recording / writing operation. 3. A bi-stable spring which urges the guide member to be stably positioned at a position constituting the reversing paper transport path and at a position where jam clearance is possible. Item 2. The paper feeder according to Item 1.