JPH0143259Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a paper loading/unloading device used in printers and the like.

A thermal printer will be explained below as an example.

First, the outline of a conventional printer is shown in Figure 1 a, b,
Referring to c and d, 1 is a paper guide that guides the paper P, 2 is a platen, 3 is a cam that is a paper fixing mechanism provided in the notch of the platen 2, and 4 is a paper guide that guides the paper P onto the platen 2 without slack. It is a film for winding, and one end is located in front of the cam 3 in the notch of the platen 2, and the other end is located above the paper guide 1. 5 is a heat sensitive head. Note that 6 is a ribbon.

Next, attaching and detaching the paper P to and from the paper fixing mechanism and printing will be explained.

First, when the paper P is inserted rightward onto the paper guide 1 as shown in FIG. 1A, the paper P is guided by the film 4 to the cam 3 of the paper fixing mechanism. Then, the cam 3 is operated to fix one end of the paper P to the platen 2 with the cam 3. Thereafter, when the platen 2 is rotated clockwise, the paper P is pressed against the platen 2 by the film 4 and wound without slack, as shown in FIG. 1b. Then, the platen 2 is further rotated one or more times in the clockwise direction as shown in FIG. Print. When printing on the paper P is finished and you want to eject the paper P from the paper guide 1, rotate the platen 2 counterclockwise in the state shown in Figure 1c and move the paper P to the left on the paper guide 1. Let it run and drain it, then see Figure 1a.
After the state is set, the cam 3 is operated and the paper P is taken out from the printer.

However, since the film 4 has elasticity so that it can reliably guide the paper P to the cam 3 even if the paper P is curled, the film 4 is If the pressing force of the film 4 is strong, the paper P will not be sent back onto the paper guide 1 with the rotation of the platen 2 as shown in Fig. There was a drawback that P could not be discharged well.

This idea was made in view of the above points. When the rotating body rotates in the direction of wrapping the paper, braking is applied by the torque limiter and one-way clutch, and when the rotating body rotates in the direction of unwrapping the paper, braking is applied. A paper loading/unloading device is provided in which a free tension roller is provided at a position where it comes into contact with a rotating body, and paper can be smoothly inserted into and discharged from the rotating body.

This invention will be explained below based on the drawings.

First, the overall structure of a thermal printer, which is an embodiment of this invention, will be described.

Fig. 2 is a partially cutaway plan view of the printer, Fig. 3 is a side view with some parts omitted except for the casing, Fig. 4 is a rear view with some parts omitted, and Fig. 5 is a partially cutaway plan view of the printer.
Figure 6 is an enlarged side view of the paper fixing mechanism and an enlarged front view seen diagonally from above, Figure 7 is the torque limiter,
FIG. 8 is an enlarged sectional view of the one-way clutch, FIG. 8 is an enlarged side view of the platen moving mechanism, FIG. 9 is an enlarged side view of the rotating body position detection mechanism, and FIGS. 10 a and b are a plan view and side view of the ribbon. .

11 to 20 are operation explanatory diagrams. In FIG. 2, 11 is a housing, 12 is a paper guide that guides the paper P, 16 is a flap, 18 is a platen which is a rotating body supported by the housing 11 with a shaft 19, and 22 is provided on the platen 18. 34 is a tension roller, 54 is a platen moving mechanism for moving the platen 18, 64 is a ribbon delivery mechanism, 67 is a ribbon, 71 is a ribbon cassette for storing the ribbon 67, 80 is a ribbon cassette for storing the ribbon 67, and 80 is a tension roller for moving the platen 18. This is a rotating body position detection mechanism that detects the rotational position. In FIG. 3, 44 is a head moving mechanism, 77 is a paper detection mechanism for detecting the presence or absence of the paper P, and 88 is a ribbon detection mechanism for detecting the presence or absence of the ribbon 67.

Furthermore, each mechanism will be explained in detail.

As shown in FIGS. 2 and 3, the paper guide 12 and the flap 16 are provided with a side plate 13, a hole 14, and a shaft 15 between the side plates 13 to reliably guide the paper P. One end of a flap 16 is attached with the shaft 15 as the center of rotation, and a hole 17 is provided in the same portion as the hole 14 of the paper guide 12.

The platen 18 is supported by a shaft 19 in the housing 11 and is provided with a notch 20, and as shown in FIG. The body 11 is biased.

As shown in FIGS. 5 and 6, the paper fixing mechanism 22 is rotatably supported by a support plate 23 attached to both sides of the notch 20 of the platen 18, and is pressed to fix the paper P. Part cam 2
4. The cam drive piece 25 is fixed to the shaft of the cam 24 by an appropriate means, and the cam drive piece 25 is rotated clockwise (Fig. 5).
The platen 18 which biases the cam 24 against the surface of the notch 20 of the platen 18, the spring 26 stretched over one end of the cam drive piece 25, and the cam drive piece 2.
A release lever 28 supported by a support plate 27 opposite to the other end of the platen 18 and a pin 30 facing the release lever 28 is installed in the housing 11.
a solenoid lever 29 whose other end is rotatably supported by a pin 30; a solenoid 31 which is rotatably engaged with the plunger 32 and the solenoid lever 29 and attached to the casing 11; a solenoid lever 29;
A spring 33 biases the solenoid lever 29 counterclockwise so that the pin 30 does not come into contact with the release lever 28 etc. housed within the radius of the platen 18.
Consists of. The other end of the flap 16 is located within the notch 20 of the platen 18, to the left and in front of the cam 24, as shown in FIG.

The tension roller 34 is shown in FIGS. 2, 3, and 7.
As shown in the figure, the shaft 35 and the platen 18 of the shaft 35
A required number of rubber rings 36 and a shaft 3 are provided on the part facing the shaft 3.
The one-way clutch 40 provided at one end and the other end of the shaft 35 is connected to the arm 4.
1, the spring 4 is rotatably supported on the housing 11, and is stretched between the housing 11 and the arm 41.
2, the tension roller 34 is urged to come into pressure contact with the platen 18. Then, the tension roller 34 enters the notch 20 of the platen 18 and the cam 24
A stopper 43 is provided on the housing 11 to prevent damage to the housing 11. When the platen 18 rotates clockwise in FIG. 3, the tension roller 34 rotates counterclockwise as the one-way clutch 40 is connected and is braked by the torque limiter, causing the platen 18 to rotate counterclockwise. The tension roller 34 then rotates freely together with the platen 18 as the one-way clutch 40 is released in the clockwise direction.

As shown in FIG. 3, the head moving mechanism 44 includes a ribbon guide 45 which is provided with holes 46 and 47 and faces the platen 18, and which is supported by the housing 11 with an axis serving as the center of rotation, and whose tip end is located beyond the hole 46 of the ribbon guide 45. A spring 4 stretched between the housing 11 and the housing 11 so as to protrude
The ribbon stopper 48 energized by the ribbon guide 45 and the thermal head 51 are attached to the ribbon stopper 48 and the thermal head 51 is supported by the housing 11 around the shaft that is the center of rotation. It consists of a head mounting bracket 50 biased by a tensioned spring 52, an eccentric cam 53 supported by the housing 11 with a shaft serving as a center of rotation, a ribbon stopper 48,
The head mounting bracket 50 comes into contact with the eccentric cam 53 and is stopped.

As shown in FIGS. 4 and 8, the platen moving mechanism 54 has a shaft 19 opposite to the wave washer 21 side.
A cam 55 inserted so as to rotate together with the cam 55, a cam recess 56 provided in the cam 55, a cam follower 58 which is a convex part that fits into the cam recess 56, and a lever 57 rotatably attached to the housing 11; A pillar 59 attached to the housing 11 regulates the amount of movement in the rotational direction of the platen 18, a flat plate 60 attached to the pillar 59 to adjust the amount of rightward movement of the platen 18 in FIG. 4, a plunger 62 and a lever 57. The solenoid 61 and the cam follower 58, which are rotatably engaged with each other and attached to the housing 11, are connected to the cam recess 5.
The spring 63 heats the lever 57 in a counterclockwise direction away from the shaft 19 so that the lever 57 does not engage with the shaft 19 .

As shown in FIGS. 2 and 3, the ribbon delivery mechanism 64 is comprised of a ribbon delivery roller 66 that is shaped like a cylinder that is attached to a shaft 65 provided between the casings 11 and partially cut out in the axial direction.

As shown in FIGS. 10a and 10b, the ribbon 67 includes a color frame 68 having a base coated with ink, a frame 69 for holding and holding the color frame 68, and a frame 69 for displaying the color of the color frame 68. It is composed of a notch 70.

As shown in FIGS. 2 and 3, the ribbon cassette 71 includes a frame 72 and a side plate 73 that guides the ribbon 67.
Bar 7 that regulates the height of ribbon 67 provided between
4. It is composed of a ribbon stopper 75 and a spring 76 that urges the ribbon 67 upward, and it holds four pieces of four colors in one
A large number of sets of ribbons 67 are stored.

As shown in FIGS. 3 and 5, the paper detection mechanism 77 connects the paper guide 12 and the holes 14, 17 of the flap
It is composed of optical sensors 78 and 79 that detect the presence or absence of paper P at the position where the cam 24 provided on the platen 18 and the notch 20 abut.

As shown in FIG. 9, the rotating body position detection mechanism 80 includes a control plate 8 attached to the shaft 19 of the platen 18.
1. It is composed of optical sensors 85, 86, and 87 that detect holes 82, 83, and 84 provided in the control board 81.

As shown in FIG. 3, the ribbon detection mechanism 88 detects the presence or absence of the ribbon 67 on the ribbon guide 45 and
It is composed of an optical sensor 89 that detects seven colors.

Next, referring to Figures 11 to 20, we will mainly focus on the third
The printing operation will be explained with a diagram.

The rotational position of the platen 18 in FIG. 3 is the position where the optical sensor 85 of the rotating body position detection mechanism 80 detects the hole 82. When the paper P is inserted into the paper guide 12 in this state, the optical sensor 78 of the paper detection mechanism 77 detects the paper P.
is detected, and the control unit (not shown) controls the solenoid 31.
Since the plunger 32 excites the spring 3
It is absorbed against 3. Then, the solenoid lever 29 is rotated clockwise (Fig. 5) and the pin 30 is rotated.
The release lever 28 is pressed, and the cam drive piece 25 rotates counterclockwise while extending the spring 26, so the cam 24 also rotates counterclockwise and the first
As shown in FIG. 1, a gap is created between the platen 18 and the cam 24. When the paper P is further inserted, if there is any curl, it is corrected by the flap 16, passes through the gap between the platen 18 and the cam 24, and hits the surface of the notch 20. At the same time, the optical sensor 79 detects the paper P. When the start button to start printing is operated in this state, the solenoid 31 is de-energized as shown in FIG.
3. The cam drive piece 25 is returned to its original state by the force of the spring 26, and the cam 24 presses and fixes the paper P to the platen 18 by the force of the spring 26. Then, as shown in FIG. 13, the platen 18 is rotated clockwise by the control section, and the paper P is wound around it. At this time, the weight of the flap 16 prevents the paper P from loosening against the platen 18, and when the tension roller 34 comes into contact with the platen 18 as shown in FIG. Wrap paper P in one layer without loosening. Furthermore, when the platen 18 rotates clockwise and reaches the state shown in FIG.
3, the control section temporarily stops the rotation of the platen 18, rotates the shaft 65 once clockwise, and sends out the first color (cyan) ribbon 67 onto the ribbon guide 45 with the ribbon delivery roller 66.
The force of the spring 49 causes the ribbon to abut against a ribbon stopper 48 protruding above the ribbon guide 45. At this time, the ribbon guide 45 and the notch 2 of the platen 18
0 are facing each other, and the thermal head 51 is connected to the eccentric cam 53.
By pressing the head mounting bracket 50, the ribbon 67 does not protrude beyond the ribbon guide 45, so the ribbon 67 can easily fit between the platen 18 and the ribbon guide 45. The optical sensor 8 of the ribbon detection mechanism 88
When the presence or absence of the ribbon 67 and the color of the color frame 68 are detected in step 9, the control section controls the eccentric cam 53 as shown in FIG.
half turn clockwise to push down the ribbon stopper 48 from the surface of the ribbon guide 45,
The head mounting bracket 50 presses the thermal head 51 against the platen 18 by the force of the spring 52, and
8 is rotated clockwise again, and the ink in the color frame 68 is thermally transferred to the paper P by a print signal of characters or figures from the control section to the thermal head 51 according to the color of the color frame 68, and printing is performed. Note that during printing, the eccentric cam 53 and the head mounting bracket 50 are separated and come into contact with the platen 18 by the force of the spring 52.
The ribbon 67 is fed by the rotational force of the platen 18.
Then, when the platen 18 rotates to the state where printing of the first color is completed as shown in FIG. direction, the head mounting bracket 50 is pushed down against the spring 52, and the ribbon stopper 48 is raised by the force of the spring 49. However, since the ribbon 67 is present, the ribbon stopper 48
cannot protrude onto the ribbon guide 45. In this state, when a suitable ribbon ejecting mechanism (not shown) is activated to eject the ribbon 67, the ribbon stopper 48 protrudes onto the ribbon guide 45 as shown in FIG. Detect that.

Then, the control section rotates the shaft 65 once and sends out the second color (magenta) ribbon 67 onto the ribbon guide 45. After that, printing is performed in the same manner as the first color.

The third color (yellow) ribbon 67 is printed in the same way.

When the ribbon 67 of the fourth color (black) is sent out as shown in FIG. 15 and the optical sensor 89 detects that it is black, the controller energizes the solenoid 61 shown in FIG.
3 and rotate the lever 57 clockwise. At this time, since the cam recess 56 and the cam follower 58 are opposed to each other as shown in FIG. 19, the cam follower 58 enters into the cam recess 56. Thereafter, printing is performed in the same manner as described above while the solenoid 61 is energized. Therefore, the cam follower 58
comes out of the cam recess 56 as the platen 18 rotates, and a flat plate 60 is supported at the back by a pillar 59.
Since the movement of the shaft 19, that is, the platen 18, is moved in the right direction against the wave washer 21 in FIG. After that, print. And again the 18th
When the state shown in Fig. 19 is reached, the cam follower 5
8 enters the cam recess 56, the platen 18 returns to its original position by the force of the wave washer 21, and the solenoid 61 is deenergized, so the plunger 62 returns to its original position by the force of the spring 63, and the cam follower 58 and The cam recess 56 is disengaged. Further, even if the ribbon 67 is not on the ribbon guide 45, it will not be fed out, and the platen 18 will not be fed out by the optical sensor 8.
7 rotates until the hole 84 is detected in FIG. 20, and one end of the paper P is above the paper guide 12 and is pressed against the platen 18 by the weight of the flap 16 and stops. The control unit rotates the platen 18 counterclockwise from the state shown in FIG.
discharge. In this stroke, the tension roller 34 is not braked by the one-way clutch 40 and rotates together with the platen 18 through the paper P, so that the paper P sandwiched between the platen 18 and the flap 16
is discharged without any slack. Further, one end of the paper P is guided by the flap 16, rides smoothly onto the paper guide 12, and is ejected, and in the state shown in FIG.
5 detects the hole 82, the rotation of the platen 18 is stopped. At the same time, or by pressing the print end button, the solenoid 31 is energized to attract the plunger 32, rotate the cam 24 counterclockwise, create a gap between the cam 24 and the platen 18, and press the print end button. Release the fixation of P. Then, when the paper P is pulled out from the paper guide 12, the optical sensor 7
The output disappears in the order of 9 and 78, and solenoid 31
When the excitation is released and the gap between the platen 18 and the cam 24 disappears, the series of operations ends.

Note that the above-mentioned embodiment shows an example of each mechanism, and the paper fixing mechanism 22 may operate the cam drive piece 25 directly by the plunger 32 of the solenoid 31. Further, the head moving mechanism 44 moves the head mounting bracket 50 to which the ribbon stopper 48 and the thermal head 51 are attached by rotating the eccentric cam 53 to the ribbon guide 45.
Although the ribbon stopper 48 and the head mounting bracket 50 may be moved up and down by driving a rack or the like having a reverse taper, the ribbon stopper 48 and the head mounting bracket 50 may be moved up and down. Furthermore, if the platen moving mechanism 54 is operated for anything other than black, color misregistration will be detected, and if the platen moving mechanism 54 is operated after the black density has been achieved to a certain extent by printing three colors, the gap between the heat-sensitive elements will be filled. Effective for expressing gradations in dark areas. Further, the platen moving mechanism 54 may not include the cam 55, and the cam recess 56 may be provided directly on the shaft 19 of the platen 18, and the spring 63 may be omitted if the lever 57 can be returned by its own weight. Furthermore, the paper mechanism mechanism 77
may be only the optical sensor 78. Further, the rotating body position detection mechanism 80 does not include the control plate 81, and the platen 1
A bar code or the like may be provided directly on the side surface of the sensor 8 to provide one optical sensor. Furthermore, the paper P may be other materials such as a film.

Further, although the paper loading/unloading device of a printer has been described, it goes without saying that the present invention can be implemented not only for printers but also for other devices.

As explained above, the paper loading/unloading device of this invention is equipped with a tension roller that is braked when the paper is wrapped around the rotating body, and rotates freely by the rotational force of the rotating body when the rotating body unwraps the paper. Therefore, there is an advantage that the paper can be tightly wrapped around the rotating body, and that the paper can be smoothly discharged along with the rotation of the rotating body when the paper is discharged.

[Brief explanation of the drawing]

Figures 1a, b, c, and d are explanatory diagrams for explaining the outline and operation of a conventional printer, and Figures 2 to 9 are thermal printers showing an embodiment of this invention; The figure is a plan view, Figure 3 is a side view, Figure 4 is a rear view, Figures 5 and 6 are an enlarged side view of the paper fixing mechanism and an enlarged front view as seen diagonally from above, Figure 7 is a torque limiter, Enlarged sectional view of one-way clutch, No. 8
The figure is an enlarged side view of the platen moving mechanism, Figure 9 is a side view of the rotating body position detection mechanism, Figures 10a and b are a plan view and side view of the ribbon, and Figures 11 to 20 are operation explanatory diagrams. be. In the figure, 11 is a housing, 12 is a paper guide, 16 is a flap, 18 is a platen, 21 is a wave washer, 22 is a paper fixing mechanism, 34 is a tension roller, 37 is a spring, 38 is a washer, 39 is a sleeve, 40 1 is a one-way clutch, 44 is a head moving mechanism, 54 is a platen moving mechanism, 64 is a ribbon feeding mechanism, 67 is a ribbon, 71 is a ribbon cassette, 77 is a paper detection mechanism, 80 is a rotating body position detection mechanism, 88 is a ribbon detection Mechanism, P is paper.

Claims (1)

[Scope of utility model registration request] In a paper attachment/detachment device that fixes paper to a paper fixing mechanism provided on a rotating body and wraps the paper around the rotating body, when the rotating body rotates in the direction in which the paper is wound, braking is performed by a torque limiter and a one-way clutch. A paper attachment/detachment device characterized in that a tension roller which is free when the rotating body rotates in a direction in which the paper is unwound is provided at a position in contact with the rotating body.