JPH0121794B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a printer that winds recording paper around the outer periphery of a platen and feeds the paper to form a recorded image with a recording head, and a recording paper setting method therefor.

(Prior Art) Conventionally, in this type of printer, it is necessary to set the recording paper before starting the recording operation, but when setting the recording paper on the platen, there are the following drawbacks. In other words, in all wire dot printers, thermal printers, and inkjet printers, a paper guide is placed in the space required for the recording head to form a recorded image between the recording head and the platen that the head faces. cannot be set. Therefore, when the platen is rotated to feed the recording paper, the leading edge of the recording paper hits the recording head without being wrapped around the platen, resulting in a jamming phenomenon of the recording paper. As a means to avoid this, the construction means shown in FIGS. 1 and 2 have been implemented. This will be explained below with reference to the same figure.

FIG. 1 is a left front perspective view of a conventional embodiment, and FIG. 2 is a left side view of FIG. 1. In the figure, 1 is a platen for feeding the recording paper P wrapped around its outer periphery, 2 is a support shaft of the platen 1, and the recording paper P is wound around the outer periphery of the platen 1 in the direction of the arrow in FIG. It is fed by a platen 1 that rotates counterclockwise. 3 is a recording head for forming a recorded image on the recording paper P, 4 is a carriage for mounting the recording head 3, 5 is a guide shaft that fits into the carriage 4, and 6 suspends the carriage 4 together with the guide shaft 5. It is a subshaft. The carriage 4 is slidably guided by a guide shaft 5 and a subshaft 6. 7 is fixed to the carriage 4 with a synchronized belt, and is stretched by an idle pulley 8 and a drive pulley 9. Reference numeral 10 denotes a space motor which is directly connected to the drive pulley 9, and the carriage 4 carrying the recording head 3 slides on the guide shaft 5 and the subshaft 6 parallel to the platen 1 by the forward and reverse rotation of the space motor 10. It's summery. 1
1 guides the recording paper P fed by a protector fixed to the carriage 4 toward the platen 1 side, and 12 guides the recording paper P guided by the protector 11.
This is a guide board for guiding the vehicle along a preset route.

The operation for feeding the recording paper P and guiding it along a predetermined route in the above configuration will be explained.

In FIG. 1, when the recording paper P is fed to the platen 1, a detector (not shown) detects the leading edge of the recording paper P, and the carriage 4 is moved to approximately the center of the platen 1 by the drive of the space motor 10. . When the recording paper P is further fed in this state, the leading edge of the recording paper P is guided by the protector 11 to follow the route shown in FIG. When the recording paper P is further fed, it is guided by the guide plate 12 and fed to a predetermined route, completing the setting of the recording paper P.

Next, a recording operation is performed, and in a normal printer, the carriage 4 moves to the left, temporarily stops at a preset home position, and then moves to the right to form a recorded image on the recording paper P.

When a conventional printer having the above configuration and operation is applied to an inkjet printer, ink droplets are ejected from the recording head 3 and collide with the recording paper P to form a recorded image. There was a drawback that the ink adhered to the surfaces of the protector 11 and the guide plate 12 near the recording paper P, and the adhered ink stained the recording paper P. Furthermore, when setting the recording paper P, the carriage 4 moves to the approximate center of the platen 1 and returns to the home position after completing the setting of the recording paper P, which consumes extra time and further reduces the recording on the platen 1. There were disadvantages such as poor adhesion of the paper and lifting of the recording paper P, which adversely affected the quality of the recorded image, and poor visibility because the guide plate 12 blocked the recorded image.

(Object of the Invention) The present invention has been made in view of the above-mentioned points, and an object thereof is to bring the recording paper into close contact with the outer peripheral surface of the platen, reliably guide it to a predetermined position, and to shorten the setting time. The purpose is to provide printers.

(Structure of the Invention) In order to automatically set the recording paper on the platen, the present invention configures the paper set roller shaft to be freely rotatable around the support shaft, and controls the circumferential surface of the platen to rotate in forward and reverse directions. When setting the recording paper, the front edge is rotated in the same direction as the platen while being held by a paper set roller, and will be described in detail below.

(Example) The present invention will be explained below based on an example. FIG. 3 is a right front perspective view showing the first embodiment of the present invention;
The figure is a right side view of FIG. 3, and FIG. 5 is an explanatory diagram of the operation of one embodiment of the present invention.

First, the configuration when applied to an inkjet printer will be explained with reference to FIGS. 3 and 4.

Reference numeral 1 designates a platen for feeding the recording paper P by wrapping it around its outer circumferential surface, and reference numeral 2 designates a support shaft of the platen 1.
The recording paper P is wound around the outer peripheral surface of the platen 1 and is fed by the platen 1, which rotates clockwise in the direction of the arrow in FIG. 3 is a recording head for forming a recorded image on the recording paper P. As shown in FIG. 3, when setting the recording paper P on the platen 1,
It is retracted further to the left outer side than the left end of the nozzle, and is opposed to a sensor section (not shown), which detects the flow velocity of the ink ejected from the nozzle and checks whether a normal recorded image is obtained.

13 is an LF motor using a pulse motor for rotating the platen 1 and feeding the recording paper P, 14 is an LF motor pulley fixed to the LF motor 13, and 15 is a synchronized belt hooked around the LF motor pulley 14. , 16 are fixed to the support shaft 2.
The power of the LF motor pulley 14 is transferred to the synchro belt 1.
5, which is a platen pulley that rotates the platen 1.

Reference numeral 17 denotes a paper set motor using a pulse motor, which is a power source for rotating the paper set lever 23 forward and backward along the outer peripheral surface of the platen 1;
is a motor gear fixed to the shaft of the paper set motor 17, 19 is an idle gear arranged to mesh with the motor gear 18, 20 is a drive shaft to which the idle gear 19 is fixed and transmits rotational force, and 21 is a Drive gears are fixed to the drive shaft 20, one each on the left and right. Reference numeral 22 denotes a paper set gear rotatably formed around the support shaft 2, which meshes with the left and right drive gears 21, and is rotated by the power of the paper set motor 17. 23 is fixed integrally with the paper set gear 22, has a U-shaped groove 23a at its tip, and has a spring post 23b on a line connecting the U-shaped groove 23a and the support shaft 2.
The paper set lever further includes a fan-shaped cam 23c. 24 is a paper set roller shaft slidably inserted and suspended in the U-shaped groove 23a of the paper set lever 23; 25 is the paper set roller shaft 24;
a paper set roller rotatably inserted into the
6 is hung on one end of the paper set roller shaft 24, and the other is hung on the spring post 23b of the paper set lever 23, which applies tension to the paper set roller shaft 24 toward the center of the support shaft 2, and loads the recording paper P. This is a spring for holding the paper set roller 25 between the outer peripheral surface of the platen 1 and the paper set roller 25.

27 is a paper set lever detector for detecting the fan-shaped cam 23c forming a part of the paper set lever 23; 28 is a first pressure roller that is pressed against the outer peripheral surface of the platen 1 and is used to feed the recording paper P; 29 is the first pressure roller for feeding the recording paper P; A first pressure roller shaft 30, which rotatably suspends the first pressure roller 28, is pressed against the outer peripheral surface of the platen similarly to the first pressure roller 28, and a second pressure roller 31 is a second pressure roller shaft for feeding the recording paper P. A second pressure roller shaft 32, which rotatably suspends the pressure roller 30, has its central portion fixed to the lower sheet guide 34, and both ends thereof are in pressure contact with the first pressure roller shaft 29 and the second pressure roller shaft 31.
This is a leaf spring for pressing the pressure roller 28 and the second pressure roller 30 against the outer peripheral surface of the platen 1. 33 is a top sheet guide for guiding the recording paper P to the platen 1, 34 is a lower sheet guide for guiding the recording paper P to the bottom of the platen 1, and 35 is attached to the top sheet guide 33 and the lower sheet guide 34. , a detector for recognizing and detecting that the recording paper P has been fed to the platen 1, and a detector 36 for detecting that the recording paper P has been set on the platen 1 and has been fed to a preset position. This is a paper leading edge detector. The arrow 37 indicates the rotation range of the paper set lever 23, and the two-dot chain line at the tip of the arrow indicates the rotated position.

Next, referring to FIG. 5, the operation of setting the recording paper P will be explained. First, each of the figures in FIGS. 5A to 5E shows the setting operation of the recording paper P in the order of each step.
FIG. 5A shows a state in which the recording paper P is not set on the platen 1. In the figure, when the recording paper P is supplied to the platen 1 from the recording paper feeding mechanism (not shown), the detector 35 detects the leading edge of the recording paper P. When the detector 35 detects the leading edge of the recording paper P, a control circuit (not shown) drives the paper set motor 17 and the LF motor 13 shown in FIG. 4, the platen 1 rotates clockwise, and the paper set lever 23 moves. Start rotating counterclockwise.

At this point, the recording paper P is being fed by the driving force of a recording paper feeding mechanism (not shown).

Note that the fan-shaped cam 23c forming a part of the paper set lever 23 is the paper set lever detector 27.
, and detects that the paper set lever 23 is at the home position.

FIG. 5B illustrates the next step, in which the paper set lever 23 driven by the paper set motor 17 is
The platen 1 rotates to a preset recording paper standby position and then stops, and the platen 1 is rotated clockwise by the LF motor 13, and the recording paper P is fed from a recording paper feeding mechanism (not shown). It shows the condition.

FIG.
The recording paper P is further fed between the paper set roller 25 and the platen 1, and is held between the paper set roller 25 and the platen 1 by the tension of the spring 26. Note that the illustrated dimension l indicates the length of the leading edge of the recording paper P fed out from the center of the paper set roller 25.
This length l is calculated by converting the leading edge of the recording paper P - the length of the detector 35 into the number of steps of the LF motor 13, and then converting the length of the leading edge of the recording paper P by the detector 35 to the length corresponding to the above converted value. This length is uniquely determined by driving the motor 13, and when the recording paper P is fed by a length l from the paper set roller 25 (LF
When the motor 13 has rotated a set number of steps), the paper set lever 23 is driven in the same direction as the platen 1, that is, clockwise, as shown by the arrow, by the paper set motor 17 controlled by a control circuit (not shown). If the circumferential speed of the outer circumferential surface of the platen 1 is ω ₁ and the circumferential speed of the paper set roller 25 is ω ₂ , then there is a relationship of ω ₁ <ω ₂ , which is determined from the drive pulse period of the paper set motor 17 and the motor gear 18. It is set by the tooth ratio of a series of gears of the paper set gear 22, and in reality, the peripheral speed of the paper set roller 25 is set to be about 1% faster than the peripheral speed of the platen 1 in order to prevent the recording paper P from slackening.

In FIG. 5D, the front edge of the recording paper P is rotated clockwise between the platen 1 and the paper set roller 25 while being held by the spring 26, and the fan-shaped cam portion 23c of the paper set lever 23 is detected by the paper set lever detector 27. , paper set motor 1
7 is a diagram showing the point in time when the platen 1 has stopped (the platen 1 is rotating clockwise).

In Fig. 5 E, the LF motor 13 is further connected to the platen 1.
Rotate clockwise to feed the recording paper P,
When the paper leading edge detector 36 detects the leading edge of the recording paper P, the LF motor 13 stops and the paper P
This is a diagram showing the completed setting in a predetermined position.

As explained above, in this embodiment, the detector 35 recognizes the leading edge of the recording paper P, and the paper set lever 23 rotates counterclockwise to pick up the leading edge of the recording paper P and set it at a predetermined position. After stopping and waiting at the position shown in FIG. In addition, since the paper set roller 25 rotates and feeds the recording paper P while holding it at a peripheral speed slightly faster than that of the platen 1, the recording paper P is tightly wound around the outer circumferential surface of the platen 1, and Since the recording paper P can be reliably guided and set to a predetermined position and the rotation of the platen 1 does not stop while the recording paper P is being set, there are advantages such as being able to shorten the setting time. Furthermore, since the paper set roller 25 only rotates on the outer peripheral surface of the platen 1, there is an advantage that no impact noise is generated.

In the first embodiment, the structure is for setting a recording paper P of normal thickness, but a structure for setting a thick recording paper P' having a ream weight of 135 kg or more, for example, will be explained.

6 and 7A and 7B are right side views showing other embodiments of the present invention, and FIG. 8 is a sectional view of the paper set roller. This will be explained below with reference to the same figure.

In FIG. 6, reference numeral 38 indicates a paper guide disposed inside the paper set lever 23 at both ends of the platen 1, and 38a indicates a cam portion forming a part of the paper guide 38. The other configurations are the same as in the first embodiment. In FIG. 6, when the paper set lever 23 rotates counterclockwise around the support shaft 2 from the upper left of the platen 1 indicated by the solid line to the lower left indicated by the two-dot chain line, it is slidably inserted into the U-shaped groove of the paper set lever 23. The suspended paper set roller shaft 24 and the paper set roller 25 inserted into the paper set roller shaft 24 also stop at the position shown by the two-dot chain line.

At this time, the paper set roller shaft 24 rides on the cam portion 38a formed in a part of the paper guide 38, and a gap is generated between the outer peripheral surface of the platen 1 and the paper set roller 25, as shown in FIG. , to facilitate biting of the recording paper P' fed from the platen 1.

FIGS. 7A and 7B are explanatory diagrams illustrating the operation of setting the recording paper P' when the paper set roller 39 shown in FIG. 8 is used.

FIG. 8 is a sectional view of a paper set roller 39 which is rotatable in only one direction with respect to the paper set roller shaft 24 of FIG. In the figure, a one-way clutch 39a is press-fitted into the inside of the paper set roller 39, so that the paper set roller 39 is fixed to the paper set roller shaft 24.
rotates only counterclockwise, as shown by the arrow in the figure.

The operation will be explained below with respect to FIG. 7 A and B.

First, FIG. 7A shows that when the paper set lever 23 rotates counterclockwise as shown by the arrow in the figure, the paper set roller 39 incorporated into the platen set lever 23 via the paper set roller shaft 24 also moves onto the outer peripheral surface of the platen 1. It is shown that the paper set roller rotates counterclockwise around the paper set roller shaft 24.

FIG. 7B shows a state in which the recording paper P' is fed between the outer peripheral surface of the platen 1 and the paper set roller 39 and is held between the springs 26, as in the first embodiment. Note that when the recording paper P' passes under the paper set roller 39, the paper set roller 39 rotates counterclockwise even if the recording paper P' hits the surface of the paper set roller 39, so the one-way clutch 39a is It does not interfere with the passage of paper. Next, in order to set the recording paper P' in a predetermined position, when the paper set lever 23 rotates clockwise together with the platen 1 as shown by the arrow in the figure, the paper set lever 23 rotates around the paper set roller 39 as explained in the first embodiment. Since the speed is faster than the circumferential speed of the platen 1, the paper set roller 39 tries to rotate clockwise, but it does not rotate because the one-way clutch 39a is incorporated. As a result, even if the recording paper P' is thick and stiff, the recording paper P' is forcibly squeezed up by the paper set roller 39 equipped with the one-way clutch 39a, and is firmly attached to the outer peripheral surface of the platen 1. However, it has the effect of being set.

In the first embodiment, the recording head 3 is retracted further to the left outside from the left end of the platen 1. However, if the recording head 3 does not interfere with the rotating operation of the paper set roller 25, There is no need for the recording head 3 to be retracted to the left outside of the platen 1, and the recording head 3 may be configured to slide and retract in a direction perpendicular to the platen 1, or the recording head 3 may be retracted to the left outside of the platen 1.
Recording head 3 is connected to platen 1 with a fulcrum at
If the structure is such that it rotates and retreats, it is not necessary to retreat to the left outer side of the platen 1.

Furthermore, as shown in FIG. 3, the paper set roller 25 has been described as an example in which it is divided into four parts, but it may be a single roller of the required length. Although the spring 26 that applies the pressing force for holding the recording paper P is described as a tension coil spring, it may be replaced with a leaf spring.

Furthermore, in the first embodiment, when rotating while the recording paper P is held between the outer peripheral surface of the platen 1 and the paper set roller 25, the peripheral speed of the paper set roller 25 is set approximately 1% faster than the peripheral speed of the platen 1. However, if the circumferential speeds of the two are the same, or if the paper set roller 25 does not lead the leading edge of the recording paper P at the time shown in FIG. You may.

(Effects of the Invention) As explained above, in the first embodiment of the present invention, the front edge of the recording paper is held between the outer circumferential surface of the platen and the paper set roller by a spring, and the paper set lever moves slightly faster than the platen. Since the paper rotates and feeds in the same direction at high speed, it is possible to tightly wrap the recording paper around the outer circumferential surface of the platen, and it is possible to reliably guide and set the paper to a predetermined position. Since the recording paper can be set in continuous rotation without stopping, there is an advantage that the setting time can be shortened.

Furthermore, in another embodiment of the present invention, when setting thick recording paper, as explained in FIG. In addition to having the advantage of being easy to load, the paper set roller has a one-way clutch as explained in Figures 7 A and B and Figure 8, so the paper set roller has the effect of squeezing up the recording paper, and therefore can handle thick sheets. This has the advantage that the recording paper can be set in close contact with the outer peripheral surface of the platen.

[Brief explanation of drawings]

FIG. 1 is a left front perspective view of a conventional embodiment, FIG. 2 is a left side view of FIG. 1, FIG. 3 is a right front perspective view of an embodiment of the present invention, and FIG. 4 is a third view. FIG. 5 is a right side view explaining the operation of one embodiment of the present invention, FIGS. 6 and 7 A and B are right side views showing another embodiment of the present invention, and FIG. The figure is a sectional view of the paper set roller. 1...Platen, 2...Spindle, 13...LF motor,
17...Paper set motor, 22...Paper set gear, 23...Paper set lever, 24...Paper set roller shaft, 25...Paper set roller, 26
...Spring, 35...Detector, 36...Paper leading edge detector, 38a...Cam section, 39a...One-way clutch.

Claims (1)

[Scope of Claims] 1. A rotating platen with recording paper wrapped around its outer peripheral surface, and a recording head disposed opposite to the platen, and the recording paper is passed from the rear of the platen to the lower outer periphery of the recording head. A printer set between a head and the platen includes a detector that detects when recording paper is fed to a predetermined position behind the platen, and a detector that detects when recording paper is fed to a predetermined position behind the platen, and a detector that detects when recording paper is fed to a predetermined position behind the platen, and a detector that detects when recording paper is fed to a predetermined position behind the platen. a recording paper set member that is rotatably provided; a recording paper set roller that is rotatably provided on the recording paper set member and movable toward and away from the outer periphery of the platen; a pressing means for pressing against the surface; a motor for rotationally driving the recording paper setting member in both the recording paper advancing direction and the opposite direction; and guiding the recording paper from the rear of the platen to the front side of the platen along the lower outer periphery. A printer comprising a guide member. 2. In a recording paper setting method for a printer in which recording paper is set at a predetermined position on the outer periphery of a platen on the side of a recording head, a recording paper that is in contact with the outer periphery of the platen and is movable along the outer periphery of the platen in both directions of the advancing direction of the recording paper and the opposite direction thereof. A recording paper set roller is provided, and by detecting the feed of the recording paper, the recording paper set roller is moved in the opposite direction to the traveling direction of the recording paper and is placed in a waiting position for the recording paper, so that the leading edge of the recording paper is at the waiting position. 1. A method for setting recording paper in a printer, comprising: moving the recording paper set roller in the advancing direction of the recording paper when the paper passes through the platen, and feeding the recording paper to a setting position while holding the recording paper between a platen and the recording paper set roller.