JP2835353B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer.

[0002]

2. Description of the Related Art Conventionally, as means for adjusting the distance between a print head and a platen, eccentric shafts are formed at both ends of a guide shaft for guiding a print head, and the guide shaft is connected to a frame via the eccentric shaft. The support or the both ends of the guide shaft are supported on the frame via eccentric bearings, and the eccentric shaft or the eccentric bearing is rotated to adjust the distance between the print head and the platen.

[0003]

However, in the above configuration, when the eccentric shaft or the eccentric bearing is rotated, the print head cannot linearly advance and retreat with respect to the platen, and the print head and the platen cannot be moved. The facing position changes,
There has been a problem that the print quality deteriorates due to a change in the attitude of the print head.

Accordingly, it is an object of the present invention to adjust the gap by moving the print head linearly with respect to the platen so that the gap can be adjusted while always maintaining the best print quality. .

[0005]

In order to achieve the above object, a printer according to the present invention is capable of adjusting a distance between a print head and a platen, and guides the print head in parallel along the platen. A guide shaft that engages with both ends of the guide shaft to linearly guide the guide shaft in a direction in which the print head comes into contact with and separates from the platen; and a guide means at both ends of the guide shaft. An eccentric bush that fits into a portion different from the engagement portion, a positioning member fixedly provided to face each eccentric bush, an urging means for elastically contacting each eccentric bush with the positioning member, and rotating each eccentric bush Driving means for driving.

[0006] Then, the positioning member of the at least one end portion side of the guide shaft is a parallelism adjusting lever having an eccentric boss eccentric bushing in elastic contact with is arranged to be fixed swingable and any rocking position Oh Ru.

Preferably, a pipe is rotatably fitted to the eccentric boss, and the eccentric bush is elastically contacted via the pipe.

[0008]

An embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 4 show various modes of use of the printer. First, in the outer case 1 of the printer, a right side plate 11 (FIG. 5) and a left side plate 12 are supported upright on the bottom surface in the vicinity of both side surfaces of the outer case. The outer case 1 has a front cover 13 that can be opened and closed on the front surface (left side in FIG. 1), a partition cover 14 that can be opened and closed inside the case, and an upper cover 15 that can be opened and closed on the upper surface. After that, a swingable switching cover 16 is provided, and a detachable rear cover 17 is further provided on the rear surface (right side in FIGS. 3 and 4). Rear cover 1
Guide pins 18 and 19 are provided to protrude from the inner surfaces of the left and right side plates 11 and 12 in the interior 7.

In this printer, the rear cover 17 is removed from the state shown in FIGS. 3 and 4, and the guide pins 18 and 19 are provided with a cut sheet feeder (CSF) 21 as shown in FIG. 1 or a rear tractor 22 as shown in FIG. Can be used by attaching. The CSF 21 or the rear tractor 22 is provided with guide grooves 21a, 21b or 22a, 22b that can be engaged with the guide pins 18, 19. A front tractor 23 is provided in the outer case 1 behind a lower end portion of the front cover 13 which is a swing center, so as to be swingable about a shaft 23a.

Next, the printing apparatus 3 will be described. In FIGS. 1 and 6, the print head 31 includes side plates 11 and 12.
The printer is mounted on a carriage 34 that moves in the left-right direction of the printer by upper and lower guide shafts 32 and 33 whose both ends are supported. The lower guide shaft 33 penetrates the carriage 34, and the upper guide shaft 32 guides the carriage 34 while allowing the carriage 34 to move up and down.
A platen 35 is provided so as to face the print head 31, and both ends of the platen 35 are supported by the side plates 11 and 12. As shown in FIG. 1, the ribbon cassette 36 is
Cassette support frame 3 at a position that does not hinder the movement of
7, the ribbon is fed in one direction by the forward rotation of a ribbon feed motor 38 positioned behind. An ink ribbon (not shown) is mounted on the ribbon cassette 36, and the ribbon is attached to the print head 31.
Is wound outside the range of movement. The carriage 34 is driven by a carriage motor 39 shown in FIG. The ribbon cassette support frame 37 is fixedly provided between the side plates 11 and 12.

Next, the print head 31 is moved forward and backward toward the platen 35 without changing the position facing the platen 35, so that the right and left parallelism of the print head 31 and the platen 3
The mechanism for adjusting the gap between the first and the fifth embodiment will be described with reference to FIGS. 5 is an outer surface (right surface) of the right side plate 11, and FIG. 7 is an outer surface (left surface) of the left side plate 12,
FIG. 6 shows an expanded mechanism for cutting and adjusting both side plates. First, the parallelism adjusting device 4 will be described. As described above, both ends of the guide shaft 33 are supported through the left and right side plates 11, 12 as shown in FIG.
The through holes are elongated in the vertical direction, that is, elongated holes 11 a and 12 a as guide means for guiding the guide shaft 33 in a direction in which the print head 31 comes into contact with and separates from the platen 35. Therefore, the position of the guide shaft 33 can be finely adjusted in the vertical direction along the elongated hole. Both side plates 1 of guide shaft 33
Eccentric bushes 40, 41 having eccentric cam surfaces 40a, 41a are connected and fixed to the protruding ends from the first and second protruding ends. The eccentric bushes 40 and 41 are provided with tooth profiles 40b and 41b. A positioning member is provided at a position in contact with the eccentric cam surface 40a. A pin 42 projects from the right side plate 11, and an eccentric boss portion 43a having an eccentric outer peripheral surface is fitted to the pin. A metal pipe 44 is rotatably fitted to the portion. Pipe 44 is eccentric cam surface 40
a. A parallelism adjusting lever 43 is provided integrally with the boss 43a, and this lever can swing about the pin. A click protrusion 43b provided at the tip of the parallelism adjustment lever 43 selectively engages with a plurality of click holes 11b... Provided on the right side plate 11 on a circle centered on the pin 42. It has become. A pin 45 protrudes from the left side plate 12 as a positioning member for the eccentric cam surface 41a, and the eccentric cam surface 41a is in contact with this pin. Eccentric cam surface 40
L-shaped levers 46 and 47 supported so as to be swingable by center pins 46a and 47a are used to constantly make the a and 41a elastically contact the pipe 44 or the pin 45, respectively. Long holes 46b (FIG. 5) and 47b (FIG. 7) which are long in the left-right direction are provided at lower ends of both levers 46 and 47, and both ends of the guide shaft 33 penetrate through these long holes. Both levers 46, 47
A tension spring 48 is hung on the upper end of the eccentric cam surface 40a.

Since the parallelism adjusting device 4 has such a configuration, when there is a problem in the parallelism between the print head 31 and the platen 35 during the assembly of the printer, the click projection 43 is used.
b and the click position of the click hole 11b is changed. This causes the parallelism adjustment lever 43 to swing, so that the boss portion 43a
Rotates about the pin 42, which causes the pipe 44 to rotate.
The position of contact between the eccentric cam surface 40a and the eccentric cam surface 40a slightly moves up and down.
That is, when the small-diameter portion of the boss portion 43a is at a position in contact with the eccentric cam surface 40a, the contact position slightly rises,
Accordingly, the right end of the guide shaft 33 rises. Conversely, when the large diameter portion of the boss portion 43a is at a position in contact with the eccentric cam surface 40a, the contact position is slightly lowered, so that the right end of the guide shaft 33 is lowered. In this way, based on the left end of the guide shaft 33,
The right end of the guide shaft 33 is moved up and down, and this elevation is transmitted to the print head 31 via the carriage 34 and
Can be adjusted. Since this movement of the guide shaft 33 is restricted by the long hole 11a of the right side plate 11, the position facing the platen 35 is not changed.

Next, the adjusting device 5 for adjusting the gap between the print head 31 and the platen 35 will be described. 5 and 6
As shown in FIG.
Is stuck. A gear 51 meshes with a pinion 50a fixed to the drive shaft of the motor 50, and a gear 52 having a notch meshes with the pinion 51a of the gear.
A first lever 53 is connected to the gear 52 via a pin 53a. A microswitch 54 is fixed on the lever. On the other hand, the tooth profile 40b of the bush 40 includes
A gear 55 having a notch meshes with a pin 56
The lever 56 is connected via a. First lever 53
The second lever 56 and the second lever 56 are connected to each other at the end opposite to the portion where the pins 53a and 56a are connected to the gears 52 and 55, and are in a mutually overlapping state. Stopped. The lever 56 is provided with a detection piece 56b for pressing / opening the operation projection of the microswitch 54 to turn on / off the switch.
The angle of the notch of the gear 55 is the same as that of the initial switch 5.
The detection piece 55a is used to turn on and off this switch by pressing and releasing the operation projection 8. Normally, the operating projection of the micro switch 54 is pressed by the detecting piece 56b by the spring 57, and is in the ON state. The operating projection of the initial switch 58 is not pressed by the detecting piece 55a, and is in the OFF state.

Since the gap adjusting device 5 has such a configuration, when adjusting the gap with the recording paper inserted between the print head 31 and the platen 35, the gap adjusting motor 50 is driven to drive the pinion. When the clock 50a is rotated clockwise, this rotation is transmitted to the gear 52 via the gear 51, and moves the lever 53 to the left. This movement is transmitted to the lever 56 via the microswitch 54 and the detecting piece 56b, and rotates the gear 55 clockwise in FIG. 5 and the bush 40 counterclockwise. Due to this rotation, the small-diameter portion of the eccentric cam surface 40a comes into contact with the pipe 44, so that the guide shaft 33 moves in the direction in which the platen 35 separates, that is, rises. Gear 55
Due to this clockwise rotation, the detecting piece 55a approaches the initial switch 58, and finally presses its operating projection to switch the switch on. Thus, the ascending position (initial position) of the print head 31 is detected.

Then, when the gap adjusting motor 50 is driven in reverse to rotate the pinion 50a in the counterclockwise direction, this rotation is transmitted to the gear 52 via the gear 51 to move the lever 53 to the right. Since the lever 56 also moves rightward following the lever 53, the gear 55 rotates counterclockwise, the pressing of the switch 58 by the pressing piece 55a is released, and the switch is returned to the off state. Turn clockwise. By this rotation, the large-diameter portion of the eccentric cam surface 40a comes into contact with the pipe 44, so that the guide shaft 33 descends in the direction approaching the platen 35, and finally the print head 31 comes into contact with the recording paper and descends further. Move to a position where you cannot do it. If the motor 50 continues to rotate in the same direction, the lever 56 can no longer follow the movement of the lever 53 rightward.
Is extended, and only the lever 53 moves, and the microswitch 54 moves rightward together with the lever. Therefore, the detecting piece 56b cannot press the operation protrusion of the microswitch 54, and the switch is turned off. Thereby, the advance position of the print head 31 is detected.

Then, the gap adjusting motor 50 is again driven to reverse, and the lever 53 is moved to the left in the same manner as described above. At the beginning of this movement, the spring 57 compresses by the amount of extension, and during that time, the lever 56 does not follow the lever 53. Therefore, the pressing piece 56b receives the force of the spring 57 again and presses the operating projection of the switch 54, and the switch 56 is pressed. Return to ON state. The print head 31 is retracted from this position by a desired gap amount. That is, when a drive signal corresponding to the movement amount, for example, a corresponding number of pulse signals is supplied to the gap adjustment motor 50, the motor pinion 50a rotates clockwise by a predetermined amount, and the print head is rotated in the same manner as described above. 31 is retracted by a predetermined amount, so that an optimal cap can be set between the plate 31 and the platen 35.

Next, the paper feeder 6 will be described. FIG.
As shown in FIG.
1,62 are provided. As shown in FIG. 12, the paper feed rollers 61 and 62 are transmitted from the motor pinion 60a of the paper feed motor 60 to the gear 63, and transmitted from the pinion 63a to the gear 64 and the gear 65, and the paper feed roller 61 shown in FIG. , 62 are driven in conjunction with each other.
As shown in FIG. 1, driven rollers 61a and 62a provided on the print head 31 side elastically contact the paper feed rollers 61 and 62, as shown in FIG. 1, and the paper feed rollers 61 and 62 and the driven rollers 61a and 62a. And the paper is fed in pairs.

The driven roller 61a on the side close to the front cover 13 is, for example, required to be miniaturized.
, The presence of the driven roller 61a may hinder the replacement when the print head is replaced. Therefore, a mechanism for moving the driven roller 61a to a position where it does not hinder the replacement work of the print head 31 is adopted. As shown in FIG.
8 and a non-paper feed position that does not make elastic contact as shown in FIG.

The switching mechanism will be described. As shown in FIGS. 8 to 10, the switching lever 6 is provided on both inner surfaces of the left and right side plates 11, 12 so as to be swingable by pins 66a.
6, 66 are supported, and a plate 67 is provided between the two switching levers.
Are connected by As shown in FIG. 10, a U-shaped long groove 66b is formed in the switching lever 66, and the shaft of a driven roller 61a is fitted into this long groove as shown in FIG. . One end of a spring 68 bent in a U-shape is locked to the shaft of the driven roller 61a,
The driven roller can elastically contact the paper feed roller 61. The swing of the switching lever 66 is performed manually, and when it is necessary to replace the print head 31,
The partition cover 14 shown in FIG. 1 is opened, the lock by the slide plate 70 described later is manually released, and the switching lever 66 is swung to set the driven roller 61a to the non-paper feed position (solid line position in FIG. 8).

Next, the roller friction switching device 7 will be described. It is desirable that the elastic force of the driven roller 61a against the paper feed roller 61 be large for cut sheets and small for continuous paper among the papers used in this printer. Thus, the elastic contact force (roller friction) of the driven roller 61a with respect to the paper feed roller 61 can be selected from one of two different elastic contact forces of strong and weak, and the driven roller 61a is positioned at each position where a different elastic contact force is generated. A roller friction switching device 7 is provided. Next, a configuration of the left side plate 12 will be described with reference to FIGS.

From the switching lever 66, the left and right side plates 11,
A positioning pin 66c is protruded toward 12. A sliding plate 70 is provided on the outer surface of the left side plate 12 so as to be vertically movable. At the upper end of the sliding plate 70, an operation pin 70a protruding through a vertically long hole 12b provided on the left side plate 12 is provided so as to protrude, and the protruding end of the operation pin from the side plate is pushed in. Thereby, the upper end of the sliding plate 70 can be bent. In the vicinity of the operation pin 70a, a cam piece 7 protruding through a vertically long hole 12c provided in the left side plate 12 is provided.
0b protrudes. As shown in FIG. 8, the cam piece 70b has two-stage cam surfaces 70c and 70d of an advanced position and a retracted position formed on a surface that can contact the positioning pin 66c. Since the length of the cam surface 70d far from the operation pin 70a is shorter than that of the cam surface 70c, the operation pin 70a
When the sliding plate 70 is deflected by pressing the end surfaces of the two cam surfaces, the end surfaces of the two cam surfaces are retracted to a position substantially matching the inner surface of the side plate. In this state, the switching lever 66 can swing manually. Sliding plate 7
In the middle part and the lower end part of the slot 0, the long holes 70e, 7
0f is provided, and a fixed shaft 71 protruding from the side plates 11 and 12 penetrates the elongated hole 70e of the intermediate portion. As shown in FIG. 10, a gear 63, which is one of the transmission trains from the paper feed motor 60, is provided with another pinion 63b, and a gear 72 meshes with this pinion. 73, 74 and 75 are sequentially engaged with each other, and the central shaft 75a of the gear 75 passes through the elongated hole 70f at the lower end of the sliding plate 70. The gear 75 is provided with an eccentric cam 76 integrally therewith. A cam groove is provided on the surface of the eccentric cam 76. As shown in FIG. 10, the cam groove has a small diameter circular arc cam groove 76a having a central angle of 90 degrees around the central axis 75a, and a large diameter of 90 degrees central angle starting from a position 90 degrees apart from the central axis. An arcuate cam groove 76b is connected to both cam grooves, and an inclined cam groove 76c having a central angle of 90 degrees is communicated. These cam grooves 76a, 76b, 7
A driven pin 70g protruding from the sliding plate 70 is engaged with 6c.

With such a structure, when selecting roller friction, a clutch mechanism C1 described later, which connects and disconnects between the pinion 63b in the transmission train from the paper feed motor 60 and the gear 72, is connected. Therefore, the gear 75 is rotated as shown in FIG. Since the eccentric cam 76 and its cam grooves 76a to 76c also rotate with the rotation of the gear 75,
The driven pin 70g has a small diameter cam groove 76a shown in FIG.
The sliding plate 70 is at the lowered position without being driven up from the position where the sliding plate 70 is engaged with the end of the sliding plate 70 to the position where the sliding plate 70 is engaged with the boundary between the small diameter cam groove 76a and the inclined cam groove 76c in FIG. Has stopped. When the sliding plate 70 is at the lowered position, the positioning pin 66c of the switching lever 66 is in contact with the cam surface 70c at the advanced position of the sliding plate 70, so that the driven roller 61a held by the switching lever 66 is in a spring position at the advanced position. Due to the spring force of 68, it comes into elastic contact with the paper feed roller 61.
That is, in this state, the roller friction is large as shown in FIG.

When the amount of rotation transmitted from the paper feed motor 60 to the gear 75 is large, the driven pin 70g passes through the small diameter cam groove 76a and the inclined cam groove 76c, and
The large-diameter cam groove 76 of FIG. 10D starts from a position where it engages with the boundary between the inclined cam groove 76c and the large-diameter cam groove 76b.
The sliding plate 70 is slid up to the position where it engages with the end of b, and the sliding plate 70 is driven up to move to the up position.
At the raised position of the sliding plate 70, the positioning pin 66c of the switching lever 66 is in contact with the cam surface 70d at the retracted position of the sliding plate 70, so that the driven roller 61a held by the switching lever 66 is spring-loaded at the retracted position. Due to the spring force of 68, it comes into elastic contact with the paper feed roller 61. That is, in this state, the roller friction is small as shown in FIG.

Therefore, in FIGS. 10A and 10B in which the roller friction is set large, there are a case where the CSF 21 is used (shown in FIG. 1) and a case where the manual feed is performed (shown in FIG. 3). FIG. 10 (C) with the friction set to small,
The case (D) is a case where the front tractor 23 is used (shown in FIG. 4) and a case where the rear tractor 22 is used (shown in FIG. 2).

In the roller friction switching device 7 already described, the friction is selected with respect to the front driven roller 61a in FIG. 1. At the same time, a roller friction switching device 8 for the rear driven roller 62a is also provided. As shown in FIG. 1, the driven roller 62a is opposed to the paper feed roller 62 across the paper transport path, and is in elastic contact with the roller 62 by the spring force of the leaf spring 80.
The friction between the driven roller 62a and the paper feed roller 62 can be changed by adjusting the spring force of the leaf spring 80. Therefore, the swinging plate 81 is provided above the leaf spring 80.
Is pivotally supported at the center, and the lower end of the swing plate 81 is in contact with the leaf spring 80. A cam 82 having a projection 82a is provided behind the upper end side of the swing plate 81, and the upper end of the swing plate 81 can be pressed by the projection 82a. Cam 8
The second shaft 83 protrudes from the left side plate 12 to the outer surface, and a lever 84 is fixed to the protruding end as shown in FIG. One end of a connecting lever 85 is rotatably fixed to the tip of the lever 84. The other end of the connecting lever 85 is provided with a long hole 85a in the longitudinal direction.
A protruding shaft 72a whose axis protrudes from the left side plate 12 to the outer surface penetrates the elongated hole 85a.

As shown in FIG. 11, a cam 86 is provided integrally with the gear 72 formed integrally with the protruding shaft 72a, and a cam groove is formed on the surface of the cam.
The cam groove has a small-diameter circular arc cam groove 86a having a central angle of 90 degrees counterclockwise around the protruding shaft 72a, and a large-diameter circular arc cam groove 8 having a central angle of 90 degrees starting from a position 90 degrees away from the central angle.
6b and both cam grooves are connected, and the inclined cam groove 86c having a central angle of 90 degrees is communicated. This cam groove 8
A driven pin 85b suspended from the connecting lever 85 is engaged with 6a, 86b, 86c. The cam surface on the outer peripheral surface of the cam 86 includes a small-diameter cam surface 86d and a large-diameter cam surface 86e, and both cam surfaces have a central angle of 180 degrees. Microswitches 87 and 88, which can be turned on and off by cam surfaces, are fixed to the connecting lever 85 and the left side plate 12, respectively, with an opening angle of 90 degrees about the center axis 72a.

With such a configuration, in the state shown in FIG. 11, since the driven pin 85b is engaged with the end of the small-diameter cam groove 86a, the connecting lever 85 is in the lowered position, and the lever 84 is counterclockwise. It is in the state rotated in the direction. This rotation is transmitted to the cam 82 via the shaft 83, and the swing plate 81 is pushed out by the projection 82a and swings counterclockwise as shown in FIG. 80 is strongly bent by pressing, so that the friction between the driven roller 62a and the paper feed roller 62 is large. In this position, since the operation projections of the micro switches 87 and 88 both face the small-diameter cam surface 86d, both switches are off. This is the first detection state by the two micro switches 87 and 88, and the CSF 21 shown in FIG.
This is a position where the driven pin 70g described above is engaged with the end of the small-diameter cam groove 76a.

The rotation is transmitted from the paper feed motor 60,
When the gear 72 rotates 90 degrees, the driven pin 85b is still located in the cam groove 86a, so that the position of the connecting lever 85 does not change and the friction remains large. It is in a state of being pushed by. Therefore, the microswitch 87 remains off, but the microswitch 88 is on. This is the second detection state by the two micro switches 87 and 88, and corresponds to the manual paper feed shown in FIG. 10B, and the above-described driven pin 70g has the small diameter cam groove 76a and the inclined cam groove. 76c.

When the gear 72 is further rotated by 90 degrees, the driven pin 85b is located in the large-diameter cam groove 86b.
4 rotates clockwise, and this rotation is transmitted to the cam 82 via the shaft 83. When the cam 82 rotates counterclockwise, the projection 82a pushes the rocking plate 81 from the position shown in FIG. Come off. For this reason, the swinging plate 81 does not press the leaf spring 80 at the lower end, or the pressing force is weakened, and the friction between the driven roller 62a and the paper feed roller 62 is reduced. In this position, the operation projection of the microswitch 87 is pushed by the large-diameter cam surface 86e, the microswitch 87 is turned on, and the microswitch 88 remains on. This is the third detection state by the two microswitches 87 and 88, and corresponds to the paper feed by the front tractor shown in FIG. 10C.
6c and a large diameter cam groove 76b.

When the gear 72 is further rotated by 90 degrees, the driven pin 85b is still located in the cam groove 86b, so that the ascending position of the connecting lever 85 does not change, and the friction remains small. It passes through the large-diameter cam surface 86e and faces the small-diameter cam surface 86d. Therefore, the micro switch 87 remains on, but the micro switch 88 is off. This is the fourth detection state by two micro switches,
In response to the paper feed by the tractor shown in FIG.
This is the position where the driven pin 70g described above is engaged with the end of the large-diameter cam groove 76b.

That is, by rotating the gear 72 by 270 degrees,
First to fourth by two micro switches 87 and 88
Can be detected.

The printer has four modes of use.
As shown in FIG. 1, the front cover 13 is opened, and two paper trays 13 are provided inside the front cover 13 so as to be foldable inward at a predetermined interval sufficient to support the recording paper.
This is a usage pattern in which the cut sheet P1 sent out from the rear CSF 21 is printed by the printing device 3 in a state where a is set up and the front tractor 23 swings rightward and downward. There are two paper discharge positions, one of which is a paper discharge position that is discharged forward as it is, that is, to the left after printing, and stacked on the table 115 swinging together with the front tractor 23 and the paper receiver 13a. In another case, the upper cover 15 is opened to expose the sheet receiver 15a and the upper discharge port 1a in the upper cover, and the cut sheet P
After printing on 1, the switching lever device 9 is set to the state of the chain line. The sensor (not shown) detects that the cut sheet P1 has passed through the printing device 3, and the output of this sensor causes the motor 60 for feeding the paper to rotate in the reverse direction, and the switching lever device 9 to be displaced to the state of the dashed line. Cut sheet P1
Is again conveyed rearward, and this time is guided upward, so that it comes out of the first upper discharge port 1a and the upper cover 15 and the sheet receiver 15a.
This is the paper discharge position stacked on top.

Part 2 is a front cover 1 as shown in FIG.
When the front tractor 23 is in a horizontal state and the front tractor 23 is in a horizontal state, the continuous paper P2 sent from the rear tractor 22 is used by the printing device 3 for printing. This is a paper discharge position where the paper is stacked in a folded state on a table (not shown) at the front.

The third is, as shown in FIG.
3 is opened, and the front tractor 23 is in a horizontal state, and the cut sheet P3 is supplied by hand from the front cover 13 one by one and printed by the printing device 3. In this use mode, there are two paper discharge positions, one of which detects that the cut sheet P3 has passed through the printing device 3 by a sensor (not shown), and the motor for feeding the paper is rotated in reverse by the output of this sensor. Then, the cut sheet is conveyed in a direction to return forward, and is at a sheet discharge position where it returns to the front cover 13 again. In another case, the upper cover 15 is opened in advance to expose the sheet receiving portion 15a and the first upper sheet discharging port 1a, and the switching lever device 9 is set in the state of the chain line. Cut sheets P3 are supplied manually from the front cover 13 one by one, printed by the printing device 3, conveyed backward as it is, and further guided upward, from the first upper discharge port 1a to the upper cover 15, and This is a discharge position where the paper is stacked on the paper receiver 15a.

4, the continuous paper P4 inserted from the insertion slot 1b provided below the front cover 13 when the front tractor 23 swings upward to the right as shown in FIG.
Are used by the front tractor 23 to send out and print by the printing device 3. In this case, the discharge position is 2
One of them is a paper discharge position where the paper is discharged rearward as it is after printing and is discharged from a rear paper discharge port 1c provided below the rear cover 17. In another case, the switching lever device 9 is previously set in the state of a chain line, and the switching cover 16 is swung like a chain line to close the first upper sheet discharging port 1a and open the second upper sheet discharging port 1d. Keep open. Printed continuous paper P4
Is a paper discharge position where the paper is guided upward after printing, exits the second upper paper discharge port 1d, and is guided to the rear of the printer.

The paper transport path in the above four modes of use will now be described in detail. As shown in FIGS. 1 to 4, the print head 31, the platen 35, and the paper transport path in the printing section by the paper feed rollers 61 and 62 before and after the platen are horizontally arranged, and the printed paper is printed here. Are four paths. That is, the first path is a path for discharging paper forward, which is the CS path described with reference to FIG.
F21, printed using the tractor 22 described in FIG. 2, and printed on the cut sheet P3 by manual feed described in FIG. 3, the feed direction is reversed by the printing unit. There are three ways: returning to the front.

The second path is a path for discharging the paper to the first upper paper discharge port 1a. The second path is printed using the CSF 21 described in FIG. 1, and after the printing, the feeding direction is reversed and the paper is further conveyed rearward and further upward. There are two cases, that is, the case where the printing is performed on the paper by manual feeding described with reference to FIG.

The third path is a path that is discharged to the second upper discharge port 1d, and is a case where printing is performed using the front tractor 23 described with reference to FIG.

The fourth path is a path to be discharged to the rear discharge port 1c, and is a case where printing is performed using the front tractor 23 described with reference to FIG.

Since the first upper discharge port 1a, the second upper discharge port 1d, and the rear discharge port 1c are all located behind the printing section, the paper conveyed backward from the printing section is not used. First, the sheet is switched upward or backward by the switching posture of the switching lever device 9, and then the upwardly directed sheet is manually switched by the switching cover 16 to the first upper discharge port 1 a or the second upper discharge port 1 a. 1d.

Therefore, referring to FIGS.
A description will be given of the paper discharge switching device 120 between the first paper discharge port a and the second upper paper discharge port 1d. The first upper discharge port 1 a is a path formed between the guide plate 121 and the switching lever 122, and a discharge roller 123 is rotatably supported at the upper end of the guide plate 121. The switching lever 122 is swingably supported with the paper discharge roller 123 as a swing center. The rotation of the paper feed motor 60 is transmitted to the paper discharge roller 123 as described later. Discharge roller 123
A paper receiver 15a is connected to the outside. The switching cover 16 is swingably supported by a shaft 16a.
A guide plate 124 is fixed to the inner surface. The switching cover 16 is provided with two projections 16b projecting inward from the guide plate 124, and both projections are provided on the switching cover at least with an interval wider than the width of the sheet. The tip of the projection 16b is in contact with the lower end of the switching lever 122.

Since the paper discharge switching device 120 has such a structure, when the switching cover 16 is manually swung from the state shown in FIG. 3 to the position shown by the dashed line in FIG. The projection 16b provided is the switching lever 1
When the lower end of the switch 22 is pushed, the switching lever swings around the discharge roller 123 so that the lower end contacts the lower end of the guide plate 121, and when the passage to the first upper discharge port 1a is closed. At the same time, the switching lever 122 and the guide plate 124
Are separated from each other to open a passage to the second upper discharge port 1d. When the switching cover 16 is closed, the switching lever 122 returns to the original position by the spring force, and opens the first upper discharge port 1a.

Next, the switching lever device 9 will be described with reference to FIGS. The switching lever 90 can be switched to three stages, that is, a lower position shown in FIG. 14A, a middle position shown in FIG. 14B, and an upper position shown in FIG. The drive of the switching lever 90 is transmitted from the ribbon feed motor 38 shown in FIG. That is, the gears 91 and 92 are sequentially meshed with the motor pinion 38a. A swing plate 93 is rotatably supported on the center shaft 91 a of the gear 91, and the gear 92 is rotatably supported on the swing plate 93. A sector gear 94 can mesh with a pinion 92 a of the gear 92. Sector gear 94
Is rotatably supported on a fixed shaft 94a, and a connecting bar 94b is integrally formed.

As described above, the gear 92 is attached to the swing plate 9
3, the fan gear 94 meshes with the pinion 92a. When the ribbon feed motor 38 is driven in the reverse direction and the motor pinion 38a rotates counterclockwise, the pinion 92a is The rotation is transmitted because of being pressed, but the ribbon feed motor 38 is driven to rotate forward when feeding the ribbon, and the motor pinion 3 is rotated.
When 8a rotates clockwise, the swinging plate 93 swings in a direction to escape from the sector gear 94, so that the pinion 92a does not mesh with the sector gear 94 and does not transmit rotation.

As shown in FIG. 12, a connecting bar 95 for the clutch mechanism C1 is connected to the end of the connecting bar 94b, and a connecting bar 96 for switching is further connected to this connecting bar. The coupling bar 95 for the clutch connects the clutch mechanism C1 when operating the roller friction switching devices 7 and 8 described above, and transmits the rotational force of the paper feed motor 60. As shown in FIGS. 12 and 13, a clutch lever 97 is connected to the distal end of the connection bar 95. The clutch lever 97 is pivotally supported on a central shaft 64 a of a driving gear 64 for driving the paper feed roller 61. A guide groove 97 a is provided at one end of the clutch lever 97, and a central shaft of a gear 69 meshed with the gear 64. 69a is fitted in the guide groove 97a to guide the clutch lever 97. At the other end of the clutch lever 97, a cam 97b is formed. FIG.
As shown in FIG. 3, the motor pinion 6 of the paper feed motor 60 is
The gear 63 meshing with the pinion 0a is axially slidably supported on the center shaft 98, and the pinion 63b and the gear 72 are normally separated by the spring force of the spring 98a, and the pinion 6
3a and the gear 64 are meshed. When the connecting bar 95 is lowered by the connecting bar 94b, the cam 97b pushes down the gear 63 against the spring force of the spring 98a to disengage the pinion 63a from the gear 64, as shown by the dashed line. The gear 63b is brought into mesh with the gear 72. The connection bars 94b, 95, 96 are urged upward by a spring 99.

The switching connecting bar 96 swings and drives the driving lever 100 for switching the switching lever 90 in three stages. As shown in FIGS. 12 and 14, the switching lever 90 and the driving lever 100 are connected to each other. Are the same central axis 1
01 and operate integrally.
A spring 102 is hooked on the driving lever 100, and a connecting pin 100 a is protruded from one end of the driving lever 100, and is slidably fitted in a long groove 96 a provided at a lower end of the connecting bar 96. I agree. At the other end of the driving lever 100, a locking portion 100b is formed. Locking part 100
b is positioned by being locked to one end of the determining levers 103 and 104. In this positioning state, the other end of the determining lever presses the micro switches 105 and 106 to turn on the switches. I do. Determining lever 10
The springs 103a and 104a are engaged with the microswitches 3 and 104, respectively. When the locking portion 100b is not locked to the determining levers 103 and 104, the microswitch 10 is activated by the spring force.
Release the pressure of 5,106 and turn off the switch. In FIG. 12, in which the driving lever 100 is lowered to the lowest position by the connecting bar 96, the locking portion 1 of this driving lever is shown.
00b is at a position above the double determining lever, and double determining levers 103 and 104 are springs 103a and 1b.
04a is in the neutral position by the spring force of
05 and 106 are off.

As shown in FIG. 11, on the outer surface of the left side plate 12, gears 108, 109, 110 are provided on a gear 107 provided at the end of the shaft of the paper feed roller 62 protruding from the left side plate 12.
Can be sequentially engaged. The gear 110 is a drive gear of the CSF 21 and the rear tractor 22 shown in FIGS. 1 and 2, and will be described later in detail. A clutch mechanism C2 is provided between the gear 109 and the gear 110,
The connection is disconnected by the swing of the clutch lever 111. The clutch lever 111 includes the switching lever 90 and the driving lever 10.
It is fixed to the center axis 101 of the zero and operates integrally. The gear 109 is, as shown in FIG.
2 is slidably supported in the axial direction, and is urged toward the left side plate 12 by a spring 113. The clutch lever 111 is provided at its tip with a cam portion 111a having a fan shape and an inclined surface. The cam portion 111a is engaged with the boss portion 109a of the gear 109 so that it can be pushed up against the spring 113. Has become. A gear 114 meshes with the gear 109, and a pulley 114 a provided on the gear 114 is connected to the discharge roller 1.
A belt 115 is wound around a pulley 123 a provided on the paper feed roller 23, and the rotation of the paper feed motor 60 is
3

When the switching lever device 9 is driven, the ribbon feed motor 38 is once rotated in the reverse direction to the state shown in FIG.
Is released, and the two connecting bars are raised by the spring force of the spring 99, thereby disconnecting the engagement between the pinion 63b and the gear 72 in the clutch mechanism C1. The driving lever 100
Is also free and swings clockwise by the spring force of the spring 102. At this time, the decision levers 104 and 103 get over the spring force against the spring force, and the driving lever 100
As shown in FIG. This lever 10
The switching lever 90 and the clutch lever 111 also swing by the rotation of the central shaft 101 together with 0, so that the switching lever 90 is in the lower position and the clutch lever 11
1 indicates that the cam 111a is separated from the boss 109a,
The gears 109 and 110 mesh with each other to close the clutch mechanism C2, and the rotation from the paper feed motor 60 is transmitted to the gear 110. Since the gear 110 is driven to rotate, the CSF
The rotation is transmitted to the rear tractor 21 and the rear tractor 22, and FIG.
Is used.

When the ribbon feed motor 38 is driven to rotate in the reverse direction, the sector gear 94 is rotated clockwise as described above, and the connecting bars 95 and 96 are lowered and moved to the middle position shown by the solid line in FIG. I do. At this position of the connecting bar 95, the clutch mechanism C1 is still in a state in which the clutch is disengaged, but the drive lever 100 swings counterclockwise as shown in FIG. The locking portion 100b moves to the locking lever 103 and its position is maintained. At the same time, the micro switch 105 is turned on, whereby the reverse rotation of the ribbon feed motor 38 is stopped. In this position, the switching lever 90 is in the middle position, and the clutch lever 111 is connected to the boss 1 of the gear 109.
Since 09a is lifted, the gears 109 and 110 are disengaged from each other, and the clutch mechanism C2 is disengaged. Therefore, the gear 110
, The rotation is no longer transmitted, so that the CSF 21 and the rear tractor 22 cannot be driven. Therefore, at this time, the usage pattern is as shown in FIGS.

When the ribbon feed motor 38 is driven in the reverse direction again, the sector gear 94 is rotated clockwise as described above, and the connecting bars 95 and 96 are further lowered, as shown in FIG. Move to the lower position shown. In this position of the connecting bar 95, the gear 63 descends and the pinion 63b
The clutch mechanism C1 is closed by the engagement of the gear 72 with the gear 72, and the rotation from the paper feed motor 60 is transmitted to the gear 75 in FIG. 12 so that the roller friction switching devices 7, 8 can be driven. By lowering the connecting bar 96 to the lower stage, the driving lever 100 swings counterclockwise as shown in FIG.
The locking portion 100b is locked by the determining lever 104 and its position is held, and at the same time, the micro switch 106 is turned on, and the reverse rotation of the ribbon feed motor 38 is stopped. In this position, the switching lever 90 is in the upper position and the clutch lever 111 has lifted the boss 109a of the gear 109, so that the gears 109 and 110 are disengaged and the clutch mechanism C2 is in the disengaged state. Remains.

FIGS. 15A and 15B show a state in which the CSF 21 and the rear tractor 22 are mounted and driven. As described above, the guide pins 1 are provided on both side plates 11 and 12.
8, 19 are protruding. As shown in FIG. 1 and FIG. 15A, the CSF 21 is provided with guide grooves 21a and 21b, and the guide groove 21b is formed in an open downward shape. It is formed in an open shape. Therefore, the CSF 21 is connected to the guide pin 1
8 and 19, the guide groove 21b is engaged with the guide pin 19 from above, and at the same time, the guide groove 21a is engaged.
Is engaged with the guide pin 18 from above, thereby completing the mounting of the CSF. In this mounted state, since the driven gear 21c fixedly provided in the CSF 21 meshes with the gear 110, the rotation of the driven gear 21c is applied to the picking roller 21d in contact with the cut sheet P1. The cut sheet P1 is transmitted through the row 21e and can be sent out.

As shown in FIGS. 2 and 15B, the rear tractor 22 is provided with guide grooves 22a and 22b, and the guide groove 22a is formed in an open front shape. Is formed in a shape of opening downward.
Therefore, when locking the rear tractor 22 to the guide pins 18 and 19, first, the guide groove 22a is engaged with the guide pin 18 from the rear to the front, and then the rear tractor 22 is centered on the guide pin 18. Is rotated, the guide pin 19 smoothly engages with the guide groove 22b whose lower part is open, and the mounting of the rear tractor is completed. In this mounted state, the driven gear 22c of the rear tractor 22
10, the driven gear 22c
Makes it possible to feed the continuous paper P2.

When the cut sheet P3 shown in FIG. 3 is fed from the front, the cut sheet P3 may be manually inserted between the paper feed roller 61 and the driven roller 61a.

Finally, as shown in FIG.
When using No. 3, the front tractor must be inclined upward to the right. As described with reference to FIGS. 1 to 4, the front tractor 23 takes three swinging postures around the shaft 23a. Therefore, the attitude changing device 130 of the front tractor 23 is shown in FIGS. That is, the shaft 23c of the driven gear 23b of the front tractor 23 has
A driven roller 23d is provided. Left and right side plates 11, 1
2 is provided with a shaft hole 131 for bearing the shaft 23a and a sector-shaped guide hole 132 formed by an arc centered on the shaft hole. The shaft 23c of the driven gear 23b is provided with the guide hole 132.
It is possible to move inside. The spring 133 having one end fixed,
The front tractor 23 is normally lowered rightward to the state shown in FIG. 1 by the spring 133 due to the elastic contact with the shaft 23c to urge the shaft 23c downward. On the other hand, the outer peripheral surface of the eccentric cam 76 of the roller friction switching device 7 is a cam surface, and medium-diameter cam surfaces 76e, 76e are provided on both sides of the large-diameter cam surface 76d. The diameter cam surfaces 76e, 76e and the small diameter cam surfaces form paragraph portions 76f, 76f. The roller 23d elastically contacts the cam surfaces 76d to 76f by the spring force of the spring 133.

With such a structure, the clutch mechanism C1 is closed and the motor driving force is transmitted to the gear 75 as described with reference to FIG.
That is, in the state shown in FIG. 10A, the roller 23d has fallen into the paragraph 76f of the eccentric cam 76, and therefore, the front tractor 23 is in a right-downward posture as shown in FIG. At this time, the driven gear 23b does not mesh with the pinion 69b of the gear 69, so that the continuous paper P4 cannot be sent out from the front tractor 23, and the CSF 21 is used.

When the gear 75 rotates, the roller 23d is brought into the state shown in FIG. 10B, and the roller 23d comes into sliding contact with the medium-diameter cam surface 76e. For this reason, the front tractor 23 is in a horizontal posture as shown in FIG. Also at this time, the driven gear 23b does not mesh with the pinion 69b of the gear 69, so that the continuous tractor P4 cannot be sent out from the front tractor 23, and the rear tractor 2
This is a usage pattern of No. 2.

When the gear 75 further rotates, the rollers 23d
10C, and the roller 23d is in sliding contact with the large-diameter cam surface 76d. For this reason, the front tractor 23 is in a posture of rising to the right as shown in FIG. At this time, since the driven gear 23b meshes with the pinion 69b of the gear 69, the driven gear 23b of the front tractor 23 is driven, and the continuous paper P4
Can be sent out.

When the gear 75 further rotates, the rollers 23d
Is in the state of FIG. 10D, and the roller 23d is in sliding contact with the medium-diameter cam surface 76d. Therefore, the front tractor 23 is in a horizontal posture as shown in FIG. At this time, the driven gear 23b
Does not mesh with the pinion 69b of the gear 69, so that the continuous paper P4 cannot be sent out from the front tractor 23, which is a manual feed mode.

In the above embodiment, the driven rollers 61a and 62a are driven by the paper feed rollers 61 and 62 on the driving side during paper feeding.
And the roller friction devices 7 and 8 are used to switch the elastic force between the two levels. However, any configuration may be used as long as the paper holding pressure can be switched. For example, the rollers 61a and 62a To rollers 61 and 62
May be switched to two positions, a position in contact with the roller and a position slightly apart from the rollers 61 and 62, to switch the paper holding pressure.

[0061]

As described above in detail, in the printer according to the present invention, the guide shaft engages with the guide means for linearly guiding the print head in the direction in which the print head approaches and separates from the platen. Since the eccentric bush is fitted to a portion different from the engagement portion, the rotation of the eccentric bush causes the guide shaft to move linearly in a direction in which the print head comes into contact with and separates from the platen. The gap can be adjusted while always maintaining the best print quality without changing the position facing the platen or changing the attitude of the print head.

Since the positioning member on at least one end of the guide shaft is an eccentric boss provided with a parallelism adjusting lever, the parallelism of the guide shaft can be easily adjusted by fixing this lever at an arbitrary swing position. Can be adjusted.

Further, since the pipe is rotatably fitted to the eccentric boss, when the eccentric bush rotates and the gap is adjusted, the frictional resistance between the eccentric bush and the positioning member is reduced. The load on the driving means can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first use mode of the present invention.

FIG. 2 is a sectional view showing a second mode of use of the present invention.

FIG. 3 is a sectional view showing a third mode of use of the present invention.

FIG. 4 is a sectional view showing a fourth mode of use of the present invention.

FIG. 5 is a right side view illustrating a device for adjusting the degree of parallelism of a print head with respect to a pteran and a device for adjusting a gap between the two.

FIG. 6 is a cross-sectional view illustrating a development of both adjustment devices of FIG.

FIG. 7 is a left side view illustrating an apparatus for adjusting a gap between a print head and a pteran.

FIG. 8 is a cross-sectional view illustrating a paper feeding device.

FIG. 9 is a cross-sectional view illustrating a roller friction switching device.

FIGS. 10A, 10B, 10C, 10D, 10E, and 10F are front views showing stepwise switching of roller friction.

FIG. 11 is a left side view illustrating a roller friction switching device.

FIG. 12 is a right side view illustrating the switching lever device.

FIG. 13 is a sectional view illustrating a part of the switching lever device.

14 (A), (B) and (C) are front views showing the operation of the switching lever device and the operation of other parts interlocked therewith in a stepwise manner.

FIGS. 15A and 15B are cross-sectional views illustrating a configuration of mounting a CSF selectively mounted on a rear portion of the printer and a rear tractor.

[Explanation of symbols]

 11a, 12a Guide means 31 Print head 33 Guide shaft 35 Platen 40, 41 Eccentric bush 43 Parallelism adjustment lever 43a Eccentric boss part 44 Positioning member (pipe) 45 Positioning members 46, 47 Urging means (lever) 48 Urging means ( Spring) 50 Driving means (gap adjusting motor)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-71972 (JP, A) JP-A-4-119870 (JP, A) JP-A-1-136776 (JP, A) JP-A-63-1988 256474 (JP, A) Japanese Utility Model Showa 62-55453 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 25/308

Claims (2)

(57) [Claims] 1. A printer capable of adjusting an interval between a print head and a platen, wherein the guide shaft guides the print head in parallel along the platen, and engages with both ends of the guide shaft. Guide means for linearly guiding the guide shaft in a direction in which the print head comes into contact with and separate from the platen; and eccentric fitting at both ends of the guide shaft at portions different from engagement portions with the guide means. Yes and the bush, and a positioning member which is fixedly arranged opposite to each eccentric bush, and biasing means for elastically contacted the respective eccentric bushing to said positioning member, and a driving means for rotating the respective eccentric bushing And the positioning member at least one end of the guide shaft,
If it is provided so that it can swing and can be fixed at any swing position
Both have an eccentric boss that the eccentric bush makes elastic contact with
A printer comprising a parallelism adjusting lever . 2. The eccentric boss according to claim 1,
Is that the pipe fits rotatably and
A printer characterized in that the eccentric bush is elastically contacted .