JPH0419035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper insertion device for an inkjet printer.

Inkjet printers are extremely superior in terms of high printing speed and low noise, but if the ink printed on the paper comes into contact with other parts before it dries during the printing operation, the ink will adhere to that part. This will rub the paper and stain it. Therefore, unlike a normal impact type dot printer, the carriage cannot be provided with a paper guide for guiding the paper fed to the platen to a position where the leading edge of the paper is pressed against the paper bail.

In view of the above-mentioned circumstances, the present invention has been devised to provide an ink cartridge which has a simple structure and can reliably bring the leading edge of paper fed to a platen to a position where it can be pressed by a paper bail without providing a paper guide in the carriage. An object of the present invention is to provide a paper insertion device for a jet printer.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

FIG. 1 is a diagram schematically showing the entirety of an inkjet printer 1 to which the present invention is applied, with the cover removed. The printer 1 is provided with a carriage 3 on which an inkjet type printing unit 2 is mounted so as to be movable along a guide rail 4. The carriage 3 is not provided with a paper guide for the reasons mentioned above. Instead, an appropriate number of paper gripping means 7 are provided at appropriate positions on the platen 5 to grip the leading edge of the fed paper and bring it to the position where it is pressed against the platen 5 by the paper bail 6. It is provided in the annular groove 8. As shown in FIG. 2, the platen 5 is provided with pressure rollers 9 and 10 that can move toward and away from the platen 5, and under normal conditions, these pressure rollers are pressed against the platen 5 with an appropriate pressure. . A resist claw shaft 14 in which the resist claw 11 is pivotally supported by side plates 12 and 13 such that the claw tip portion 11b touches and separates from the circumferential surface of the platen 5 slightly downstream of the position where the rear pressure roller 9 contacts the platen 5. It is provided with its upper end fixed to.

resist claw 11, pressure rollers 9, 10,
The paper bail 6 is displaced by two cams 15 and 16 provided on the same shaft outside the side plate 12 via a link mechanism. These cams are attached to the side plate 1
They are simultaneously rotated by a cam motor 17 installed inside the two.

The outer cam 15 is a cam for displacing the registration claw 11 and the pressure rollers 9, 10, and a link 18 is provided on the cam surface at the lower end of the link 18, which is pivotally supported near the center by a shaft 18'. Cam follower 19 is engaged. The upper end of the link 18 is connected to the link 21 via a pin 20, and the upper end of the link 21 is connected to the resist claw shaft 14 via a pin 22.
It is connected to a link 23 fixed to. The lower end of the link 21 is pulled to the left by a tension spring 24 stretched between the link 21 and the side plate 12, and as a result, the cam follower 19 is pressed into engagement with the cam surface of the cam 15, and as shown in FIG. At the reference position of the cam 15 shown, the resist claw 11 is held at a normal position with its tip retracted from the circumferential surface of the platen 5.

Next, as shown in FIG. 3, when the cam follower 19 is engaged with the protruding position of the cam 15, the link 23 rotates counterclockwise against the spring 24, and the tip 11b of the registration claw 11 is rotated counterclockwise. comes into contact with the circumferential surface of the platen 5. In this case, the free end of the link 23 comes into contact with a stopper 25 fixed to the side plate 12, thereby preventing the pressing force between the tip of the resist claw 11 and the platen 5 from becoming excessive.

The pressure rollers 9, 10 are attached to the side plates 12, 13.
The bracket 28 is supported at both ends of a bracket 28, which is supported by the tip of a leaf spring 27 fixed to a shaft 26 that is supported pivotally. The above-mentioned shaft 26 has an arm 2 extending downwardly.
9 is fixed, and a pin 30 is attached to its lower end. An arm 31 extending leftward is further fixed to the shaft 26, and a tension spring 32 stretched between the tip of the arm 31 and the side plate biases the shaft 26 and each member fixed thereto counterclockwise. In the normal state shown in FIG. 2, the pressure rollers 9 and 10 are pressed against the platen 5. However, as shown in FIG. 3, when the cam follower 19 is pushed to the left by the protrusion of the cam 15, the left edge of the link 18 pushes the pin 30 to the left, causing the shaft 26 to resist the force of the spring 32. Then, the pressure rollers 9 and 10 are retracted from the platen 5.

A cam follower 35 provided at one end of a link 34 pivotally supported by a pin 33 fixed to the side plate 12 engages with the other cam 16.
A link 37 is connected to the other end via a pin 36. A long hole 37a is provided at the other end of the link 37, and a paper bail lever 39 is pivotally supported on a shaft 38.
A guide pin 40 provided at the lower end of is engaged. Guide pin 40 and pin 4 fixed to side plate 12
A torsion compression spring 42 is hung between the paper bail lever 36 and the paper bail lever 36 when the guide pin 40 is on the right side of the straight line connecting the pins 38 and 41 as shown in FIGS. When biased clockwise, the paper bail 6 is pressed against the platen 5 in the normal state shown in FIG. 2, and a slight gap is created between the guide pin 40 and the right end of the elongated hole 37a.

However, as shown in FIG. 3, when the protrusion of the cam 16 and the cam fore 35 engage, the guide pin 40 engages with the right end of the elongated hole 37a of the link 37, and is pulled by the right end of the elongated hole 37a of the link 37, causing the paper bail lever to move. 39
rotates clockwise about the pin 38, and the paper bail 6 is retracted from the platen 5.

A knob 43 for manual operation is attached to the upper end of the paper bail lever 39. No matter where the cam 16 is located, by pulling this knob 43 toward you (to the right in the figure), the guide pin 40 can be extended. When the guide pin 40 moves to the left in the hole 37a and the position of the guide pin 40 comes to the left of the straight line connecting the pins 38 and 41, the paper bail lever 3 is moved by the force of the spring 42.
9 is biased clockwise, and can hold the paper bail 6 in a retracted state from the platen 5.

Note that the pressure rollers 9 and 10 have a similar mechanism, and can be manually moved toward and away from the platen 5 using a knob 44 shown in FIG.

It has already been mentioned that the two cams 15 and 16 are fixed to the same shaft and driven simultaneously by the cam motor 17, and the cam diagrams and phases of both cams are set as shown in FIG. In the figure, 1 indicates the displacement of the resist claw cam 15, and 3 indicates the paper bail cam 1.
6 indicates the displacement, and 2 indicates the displacement of the pressure roller moving pin 30 which is simultaneously driven by the registration pawl cam.

As is clear from this figure, the resist claw cam 15
There is no time when the protrusion of the paper bail cam 16 engages the cam follower at the same time, so the situation shown in FIG. 3 does not actually occur. For convenience, FIG. 3 shows in one drawing the states of the resist claw 11, pressure rollers 9, 10, and paper bail 6 when the cam follower engages with the protrusion of each cam.

Next, the structure of the paper gripping means 7 provided in the annular groove 8 of the platen 5 will be explained.

As shown in FIGS. 5 to 7, the paper gripping means 7 includes a notch 71 that is fitted from the side into the core rod 5a remaining at the center of the groove of the platen 5, and a notch 71 provided on both sides of the circular arc portion of the notch. a flange 72, two flat portions 70b provided at opposite positions on the circumferential surface for attaching gripping claws 74, and a notch for attaching a brake plate 76 that presses the platen core rod 5a fitted in the notch 71. A gripping base 70 is formed as a U-shaped member having a flat portion 70c provided on the peripheral edge adjacent to the opening of the notch 71, and screws are attached to the flat portions 70b and 70c provided on the peripheral surface of the gripping base 70, respectively. A brake plate 76 having a gripping claw 74 and a friction material 75 attached at 73 and two operating levers 78 swingably attached to one side surface of the gripping base 70 at symmetrical positions with respect to the center.
It is composed of.

The actuating lever 78 has a small bird shape and has a rounded head 78a and a tail that protrudes laterally so as to enter into a recess 70a provided in a flat surface 70b on the peripheral surface of the grip base 70. It has a tongue piece 78b and a tongue piece 78c protruding from the tail in the opposite direction to the tongue piece 78b, and is pivotally supported on the chest by a pin 77 so as to be able to freely swing.

The gripping claw 74 is fixed to the flat part 70b of the gripping base 70 near one end with a screw 73, and the opposite end 74a is bent along the bent part of the gripping base 70, and is bent by its own elasticity. It is in close contact with the peripheral surface of the gripping base 70 with an appropriate pressing force.

The notch 71 of the gripping base 70 is inserted into the platen core rod 5.
After fitting the brake plate 76 to the base 7 with the screw 73, with the friction material 75 facing the core rod 5a,
When installed at 0, the brake plate 76 and friction material 75
Due to the elasticity, the grip base 70 is positioned at a position where the inner circumferential surface of the collar 72 contacts the outer circumferential surface of the core rod 5a, and due to the frictional force between the friction material 75 and the core rod 5a, the grip base 70 is moved to a position where the inner peripheral surface of the collar 72 contacts the outer peripheral surface of the core rod 5a. It will now rotate as one.

The resist claw 11 is attached to a shaft 14 as shown in FIG.
An arm 11a is provided at a position corresponding to the annular groove 8 provided in the platen 5, and two claws 11b and 11c of different lengths protrude toward the platen 5 at the tip thereof in parallel. It is provided. As described above, when the cam follower 19 engages with the protrusion of the resist claw cam 15 and the resist claw shaft 14 rotates, the shorter claw 11
The tip of the longer claw 11c is positioned to be in contact with the circumferential surface of the platen 5, and the tip of the longer claw 11c is positioned within the groove 8 to some extent.

Further, as shown in FIGS. 9 and 10, the tip of a peeling claw 47 fixed to the machine frame 45 with a screw 46 is inserted into the groove 8 provided in the platen 5 to form a paper bail 6.
It enters a small length at an appropriate position on the downstream side of.

The operation when paper is automatically inserted by the apparatus configured as above will be explained based on the timing chart shown in FIG. 11 and the flow chart shown in FIG. 12.

In FIG. 11, 1 is an auto feed switch 2 is a cam motor 3 is a platen motor 4 is a feed motor 5 of a paper feed cassette, a resist claw cam 6 is a pressure roller moved by the resist claw cam, and a pressure roller displacement pin 7 is a paper bail cam. It is a diagram showing each on/off or displacement based on the passage of time.

When automatically inserting paper, the cam motor 17 starts rotating at the same time as the operator turns on the auto feed switch (point a), and the registration claw cam 15
Then, the paper bail cam 16 rotates 117 degrees and stops (point b). At the same time as the cam motor 17 stops, the platen motor rotates in a direction opposite to the normal paper feeding direction, and the platen rotates more than 180 degrees and stops. Also, the paper feed cassette feed motor rotates and stops after the time required for the leading edge of the paper to come into contact with the registration claw (point c). Then cam motor 1 again
7 rotates, and the cams 15 and 16 further rotate 165 degrees and stop (point d). At the same time, the platen motor rotates in the forward direction, and the platen 5 rotates approximately 270 degrees in the forward direction and stops (point e). Then the cam motor rotates,
The cam rotates 78 degrees, reaches the initial position, and stops.

Starting and stopping of the cam motor and the platen motor according to the above timing is automatically performed by sequence control using pulses transmitted at regular intervals by turning on an auto feed switch.

The operation of automatically inserting paper by the above-described operations of the cams 15, 16 and the platen 5 will be described below.

While the cam rotates 117° between point a and point b in FIG. The resist claw 1 shown in FIG. 8 rotates counterclockwise in FIG.
The tip of the shorter claw 11b is in contact with the circumferential surface of the platen 5, and the longer claw 11c is positioned slightly inside the groove 8 of the platen. When the cam follower 19 is pushed by the protrusion of the registration claw cam 15, the pin 3 shown in FIG.
0 is displaced to the left, and the pressure rollers 9 and 10 are retracted from the platen 5 against the force of the spring 31.

Then, between b and c, when the platen 5 is first reversed by more than 180 degrees, the paper gripping base 70 rotates in the opposite direction together with the platen 5 due to the frictional force between the friction material 75 and the platen core rod 5a, and As shown in FIG.
1's longer claw 11c, and then the claw 11c
As shown in FIG.
rotates, and its head 78a abuts against the collar 72 of the grip base 70 and stops. Thus, platen 5
Even if the rotational positions of the gripping claws 74 of the gripping means 7 are not aligned in the respective grooves 8 of 74a open all at once. If the platen 5 is still rotated in the reverse direction after that, the friction member 75 and the platen core rod 5a will slip.

Therefore, when the paper S is fed along the paper guide 48 as shown in FIG. 3 by the rotation of the cassette feed motor, the pressure roller 9
are retracted, so the claws 11b of the resist claws 11,
It is positioned by abutting against the inner end surface of 11c, and skew correction is performed.

Next, as the registration pawl cam 15 further rotates between c and d in FIG. The leading edge of the paper S is pressed against the platen 5, and then the registration claw 11 is pressed against the platen 5.
is evacuated from platen 5. Due to the retraction of the registration claw, the protrusion 78c of the operating lever 78 and the registration claw 1
1 disengages from the claw 11c, the gripping claw 74 comes into pressure contact with the circumferential surface 70b of the gripping base 70 due to its own elasticity, and its bent end closes and grips the leading edge of the sheet. On the other hand, the protrusion of the paper bail cam 16 engages with the cam follower 35, and the paper bail 6 is retracted from the platen 5.

Next, when the platen 5 rotates in the normal direction between d and e in FIG. , the paper S whose leading end is gripped is carried along the circumferential surface of the platen 5 to the printing start position and stopped.

Then, the cam rotates between e and f, and when it returns to its initial position, each member is in the state shown in Figure 2.
The paper bail 6 presses the paper S against the platen 5, and the paper S is reliably wound around the platen by the pressure rollers 9, 10 and the paper bail 6.

Before the platen stops, the leading edge of paper S
As shown in the figure, the paper comes into contact with the peeling claw 47, but since the leading edge of the paper is only lightly gripped by the gripping claw 74, the paper bends and is easily released from the grip.
The paper S is guided along the upper surface of the peeling claw 47. Therefore, when the platen 5 rotates due to subsequent printing operations, the paper is reliably ejected in a predetermined direction without being wrapped around the platen 5.

The above operation is carried out fully automatically using an automatic paper feed cassette, when the operator presses the auto feed switch, and the cam and platen start and stop under sequence control, and it takes only 8 seconds to insert the paper. That's about it.

When an operator manually inserts paper without using an automatic paper feed cassette, instead of controlling the cam to stop at point b and then restarting rotation at point c in Figure 11 using the number of pulses, the paper is The insertion may be detected by another detection means and the detection signal may be used. As the detection means, for example, a hole is made at an appropriate position in the paper guide 48,
The paper can be detected by a photo sensor through this, or
Various known means can be used, such as actuating a switch with a mechanical feeler.

Furthermore, in the above embodiment, two gripping claws of the paper gripping means are provided on each gripping base at 180° intervals, so the platen must be reversed by more than 180° in order to align and open the gripping claws. However, it goes without saying that if the number of gripping claws provided on one gripping base is other than two and they are provided at equal intervals, the platen reversal angle should be equal to or greater than 360° divided by that number. Nor. For example, if there are three, the angle will be 120° or more, and if there is one, the angle will be 360° or more.

As shown in FIG. 1, this printer is equipped with a paper bail 6, pressure rollers 9, 10, and knobs 43, 44 for manually moving the registration claw 11 toward and away from the platen 5 and rotating the platen forward and backward.
49, it is also possible to perform the above-mentioned operations manually.

As described above, according to the present invention, with a simple configuration,
By simply pressing the auto feed switch once, the operator can correct the skew of fed paper without installing a paper guide in the carriage and ensure that the paper is loaded at the printing start position. Significant effects can be obtained in improving printer operability and reducing costs.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the entire embodiment of an inkjet printer to which the present invention is applied, Fig. 2 is a side view of the inkjet printer in its standard state as seen from the left side, and Fig. 3 shows the cam protrusion engaged with the cam follower. 4 is a cam diagram, FIG. 5 is a side view showing the state in which the gripping claw tip of the paper gripping means is closed, and FIG. 6 is a side view showing the state in which the gripping claw tip is open. FIG. 7 is an exploded perspective view of the gripping means;
8 is a perspective view of the resist claw, FIG. 9 is a side view of the peeling claw, FIG. 10 is a top view thereof, and FIG. 11 is a timing chart when paper is inserted into the apparatus of this embodiment.
FIG. 12 is a flowchart. S... paper, 1... printer, 5... platen, 6... paper bail, 7... paper gripping means.

Claims (1)

[Claims] 1 An annular groove provided at multiple locations in the axial direction of the platen, a base provided in the annular groove, and a grip portion that can be opened and closed relative to the platen circumferential surface at a free end whose base is fixed to the base. and a gripping claw that is elastic in itself and is normally biased in the closing direction;
A gripping claw operating member provided on the base to operate the gripping claw in the opening direction, the tip of which can move in and out of the annular groove at a predetermined position; It has an engageable registration pawl, and as the platen rotates in the paper conveyance direction, the gripping pawl operating member that engages with the tip of the registration pawl rotates relative to the base to open the gripping pawl, and at the same time, the base rotates. The paper is controlled so that the resist claw exits from the annular groove after the paper reaches the resist claw that enters the annular groove, so that the gripping portion of the gripping claw closes and grips the paper. 1. A paper insertion device for an inkjet printer, comprising a paper leading edge gripping mechanism.