JPH0414635B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention moves one or more print wires disposed on a print head that reciprocates along the length of a platen toward the platen. The present invention relates to a dot matrix printer that prints on printing paper guided between the platen and the printing head.

(Prior Art) Conventionally, in this type of dot matrix printer, a printing ribbon is stretched between a printing head and printing paper, and the printing is performed by applying ink to the printing paper with the printing ribbon. was.

(Problems to be Solved by the Invention) Therefore, since the conventional dot matrix printer is provided with a printing ribbon and a ribbon feeding mechanism, there is a problem in that the configuration becomes complicated.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention provides an ink application means for applying ink onto the surface of the platen, and an ink application means along the path of the printing paper. The slits are provided parallel to each other in a flat plate shape, and have a slit surrounded on all sides through which a printing wire can be inserted near the center. guiding means for guiding and supporting the printing paper;
a feed roller that is arranged apart from the platen and feeds the printing paper between the platen and the print head; and a drive means that rotationally drives the feed roller and rotates the platen in synchronization with the rotation of the feed roller. The printing paper is partially pressed against the surface of the platen by the printing wire, and printing is performed on the printing paper on the opposite side of the printing wire.

(Function) With the above configuration, in this invention, the printing paper is reliably supported by the guide means in a state separated from the platen, and the ink applied to the platen is not inadvertently attached to the next line. When printing paper is sent by the feed roller during printing, the platen also rotates in synchronization with this, and a new ink coating surface appears on the platen surface corresponding to the printing wire, so the printing paper is moved by the printing wire to the platen. When pressed partially onto the surface of the print wire, a clear print is made on the print paper on the opposite side of the print wire.

(Example) An example embodying this invention is shown in Figs.
This will be explained according to FIG. A platen 2 is rotatably supported by a support shaft 3 between the left and right side walls 1a and 1b of the frame of the dot matrix printer. A protective frame 4 is constructed and fixed between both side walls 1a and 1b so as to cover the outer peripheral surface of the platen 2, and a slit 5 extending left and right is provided on the rear side wall of the protective frame 4.
is formed. A paper guide 6 formed by bending a thin plate is adhesively fixed to the outer surface of the rear wall of the protective frame 4, and a slit 7 narrower than the slit 5 of the protective frame 4 is provided in the center of the paper guide 6. It is formed. Support grooves 8 facing each other are formed in both side walls 1a and 1b of the frame 1 in front of the platen 2, and in the support grooves 8, an ink roller 9 impregnated with ink is rotatable on a spindle 10 and rotates back and forth. It is movably supported and urged to move in a direction in which it comes into pressure contact with the platen 2 by a leaf spring 11 on a guide plate 56, which will be described later. When the platen 2 rotates, the ink roller 9 follows and rotates, so that the ink on the ink roller 9 is applied to the outer peripheral surface of the platen 2.

At the rear of the platen 2, a base plate 12 is supported by the frame 1 so as to be movable back and forth, and a support shaft 14 is inserted and supported in the front of the upright portions 13 on both left and right sides of the base plate 12. A support shaft 14 is mounted on the base plate 12.
A head frame 15 is fitted and supported so as to be movable left and right along the longitudinal direction of the platen 2.
As shown in FIG. 5, a support wall 16 extending left and right is integrally formed on the upper surface of the front side of the head frame 15 and projects from the support wall 16.
A plurality of partition walls 17 and 18 are integrally formed on the upper surface at predetermined intervals. Alternatively, a connecting portion 19 that connects the front side portions of the front partition wall 18 to each other is integrally formed. The support wall 16 and the connecting portion 1
Support holes 16a and 19a are formed in the support hole 9, respectively, between the partition walls 17 and 18 and located outwardly on both sides. On the head frame 15 between the partition walls 17 and 18, there are seven dot forming bodies 20 (only one is shown) each having one printing wire 20a and an electromagnet 20b for moving the printing wire 20a back and forth. ) is provided, and the shaft portion 21 of each dot forming body 20 is press-fitted into each of the support holes 16a, 19a, and is also fitted onto the shaft portion 21 of each dot forming body 20 in front of the support wall 16. Retaining ring 2
2 on the head frame 15. The tip of the shaft portion of each dot forming body 20 is placed close to the platen 2 across the paper guide 6 and the slits 7 and 5 of the protective frame 4, and as will be clear from the description below, each dot forming body 20 is in charge of printing three digits of letters and numbers. Further, the head frame 15
A printing head H is constituted by each dot forming body 20.

A pair of left and right contact pins 27 are provided at a predetermined interval on the lower surface of the center of the head frame 15 and project downward through the notch 26 of the base plate 12. A cam body 29 that rotates integrally with the support shaft 28 is provided between the left and right side walls 1a and 1b of the frame 1 so as to be located below the contact pin 27, and the outer peripheral surface of the cam body 29 has an endless shape. An annular cam 30 is formed to protrude. The contact pins 27 are in contact with both left and right side surfaces of the annular cam 30. The frame 1 is provided with a print head drive motor 31, and when the cam body 29 is rotated together with the support shaft 28 via a gear transmission mechanism (not shown) based on the rotation of the print head drive motor 31, the cam body 29 is rotated. During one rotation, each dot forming body 20 is reciprocated by three orders of magnitude together with the head frame 15.

At the rear of the head frame 15, a guide rail 23 having an inverted L-shaped cross section is fixedly attached to the inner surface of the rear wall 1c of the frame 1.
A guide member 25 is attached to the upper and lower surfaces of the guide member 25, which has a sliding groove 25a that slides into contact with the guide member 25.

As shown in FIGS. 3 to 5, an actuation plate 32 extending left and right is attached and fixed to the rear lower surface of the base plate 12 by a plurality of screws 32a. , 1b are provided with tension springs 34 between the left and right protrusions 33 protruding from each other.
is installed. Based on the spring force of the tension spring 34, the head frame 15 and the base plate 12 are urged to move toward the platen 2.

A frame 1 is provided at the center of the rear edge of the operating plate 32.
A linking piece 36 is formed that penetrates the slit 35 in the rear wall 1c and projects outward from the frame 1.
Further, as shown in FIGS. 3 and 4, a support piece 3 is provided on the outer surface of the rear wall 1c adjacent to the linking piece 36.
7 is attached and fixed, and a connecting lever 38 is rotatably supported on the support piece 37 at approximately the middle thereof. One end of the connecting lever 38 is fitted into a square hole 36a formed in the connecting piece 36.

On the other hand, as shown in FIGS. 3 and 4, a solenoid 39 is installed on the inner surface of the left side wall of the frame 1.
The plunger 40 penetrates the rear wall 1c and projects outward. And that plunger 40
The other end of the connecting lever 38 is rotatably connected to the connecting lever 38. Further, rollers 41 are supported on the inner surfaces of the front end portions of the left and right upright portions 13 of the base plate 12, respectively.

When the solenoid 39 is demagnetized, the tension spring 4 is activated as shown in FIG.
3, the base plate 12 and head frame 15 are moved toward the platen 2 together with the actuating plate 32, and each roller 41 is moved to the feed roller 4, which will be described later.
2, and the base plate 12 and the like are placed in the forward position shown in FIG. The tip of each dot forming body 20 on the head frame 15 is arranged close to the outer peripheral surface of the platen 2.

On the other hand, when the solenoid 39 is energized, the plunger 40 is moved from the protruding position shown in FIG. 3 in the retracted direction, and with this movement, the connecting lever 38 is rotated in the direction of the arrow in the figure. Therefore, through the connection between the connecting lever 38 and the connecting piece 36, the actuating plate 32 and the base plate 1 resist the biasing force of each tension spring 34.
2, each dot forming body 20 is moved together with the head frame 15 in a direction away from the platen 20, and as shown in FIG.
A predetermined gap is formed between the platen 2 and the platen 2.

As shown in FIGS. 1 to 3, a feed roller 42 is rotatably supported by a support shaft 43 between the left and right side walls 1a and 1b below the platen 2.
A driven gear 44 provided at the outer end of the support shaft 43
It is rotated in a predetermined direction by a feed drive motor as a drive means (not shown) via a gear transmission mechanism including an intermediate gear 45 meshing with the driven gear 44. Further, this feed drive motor also serves as a platen drive motor, and is configured to rotate the platen 2 in synchronization with the feed roller 42 via a transmission mechanism (not shown). A support shaft 46 installed between the left and right side walls 1a and 1b adjacent to the feed roller 42
A pair of roller supports 47 and 48 are rotatably supported at each pair of bending portions 49 . A presser roller 50 is rotatably supported between the upper ends of the bent portions 49 of each of the roller supports 47 and 48, and as the roller supports 47 and 48 rotate, each presser roller 50 becomes a feed roller. 42 so that it can be pressed into contact with and separated from it. In addition, each roller support 4
A protruding piece 51 that protrudes upward is formed on the front upper edge of each of the bent portions 49 7 and 48 . Further, below each roller support 47, 48, the frame 1
A pair of solenoids 52 are mounted on the bottom side 1d of the roller, and a plunger 53 of each solenoid 52 is connected to a linking piece 54 of each of the roller supports 47, 48. Moreover, each roller support body 47, 48
and the bottom side 1d are each roller support 4 in the direction of pressing the presser roller 50 against the feed roller 42.
A tension spring 55 is tensioned to bias the parts 7 and 48 to rotate. When each solenoid 52 is demagnetized, each presser roller 50 is pressed against the feed roller 42 based on the biasing force of each tension spring 55, as shown in FIG. Furthermore, when the solenoid 52 is energized, as shown in FIG.
Each of the roller supports 47 and 48 is rotated clockwise in FIG. 1 against the urging force of each tension spring 55, and each presser roller 50 is placed in a position away from the feed roller 42.

A guide plate 56 is installed between the left and right side walls 1a and 1b so as to cover the lower surfaces of the feed roller 42 and the ink roller 9, and the guide plate 56 has a guide plate 56 on which each protrusion 51 of the roller supports 47 and 48 is attached. Opposingly, a substantially J-shaped leaf spring 57 is attached at its base end and protrudes downward through a slit in the guide plate 56. An upright piece 59 formed on the front edge of the bottom portion 1d so as to be located below the guide plate 56 has a raised piece 59 for guiding and supporting continuous paper.
Each solenoid 52 from below the feed roller 42
A paper guide 60 is detachably attached with a screw 61 and extends forward while being curved. This paper guide 60 is provided with a slit 62 that allows the protruding pieces 51 of each of the roller supports 47 and 48 to protrude from the upper surface thereof.

When each solenoid 52 is demagnetized, each roller support 47,
The protruding piece 51 of 48 is connected to the slit 62 of the paper guide 58.
A predetermined gap is formed between the protruding piece 51 and the leaf spring 57. Therefore, in this state, continuous paper can be fed from the front of the frame 1 along the upper surface of the paper guide 60 to the feed roller 42 through between the protrusion 51 and the leaf spring 57.

On the other hand, when the solenoid 52 is energized, as shown in FIG. 5
0 is placed at a position spaced apart from the feed roller 42. Therefore, in this state, if the head frame 15 is placed at the rear position shown in FIG.
0, and the lower edge of the cut sheet P can be brought into contact with the upper end side of the paper guide 60 to regulate the insertion position.

In addition, both side walls 1 are located above the front part of the frame 1.
A cover body 6 that covers the ink roller 9 is provided between a and 1b.
At the same time, a cover 64 is attached to the upper surface of the frame 1 to cover the head frame 15 and the like, and a cutter 65 for cutting continuous paper is provided at the front edge of the cover 64.

Next, the operation of the dot matrix printer configured as described above will be explained. First, when inserting the cut sheet P between the platen 2 and the dot forming body 20, the solenoid 3 shown in FIGS.
When 9 is energized, the plunger 40 is moved to the closing position, and the connecting lever 38 is accordingly rotated in the direction of the arrow in the figure. Therefore, the connecting lever 3
8 and the square hole 36a of the actuating plate 32, the actuating plate 32, the base plate 12, and the head frame 15 are moved rearward against the urging force of each tension spring 34. As the head frame 15 moves backward, the bottom of the sliding groove 25a of the guide body 25 on the head frame 15 is engaged with the front edge of the guide rail 23 to regulate the position of the head frame 15, and the head frame 15 is moved to the position shown in FIG. It is placed in the position shown.

Based on this backward movement of the head frame 15,
Each dot forming body 20 is arranged at a position apart from the platen 2, and as shown in FIG.
A predetermined gap is formed therebetween.

Next, a pair of solenoids 52 (1
When the plunger 53 is excited, the plunger 53 is moved to the retracted position, and based on this movement, the roller supports 47 and 48 are moved around the support shaft 46 against the biasing force of the tension spring 55 as shown in FIG. The pressure rollers 50 on the roller supports 47 and 48 are spaced apart from the feed roller 42 and placed in the position shown in FIG.
The protrusions 51 of 7 and 48 project onto the paper guide 60 through the slits 62 of the paper guide 60 and are engaged with the corresponding leaf springs 57.

Therefore, if the cut sheet P is inserted from above between the paper guide 6 and the head frame 15 in this state, it will be introduced to the upper end of the sheet guide 60 through between the presser roller 50 and the feed roller 42. can do. Then, the lower end of the cut paper P in the filter is engaged with the upper end side of the paper guide 60, and its position is regulated.

Next, when each solenoid 52 is demagnetized, each roller support 4 is
7 and 48 are rotated back counterclockwise in Fig. 2,
Each presser roller 50 is pressed against the feed roller 42,
A cut sheet P is held between both rollers 42 and 50. Also, the solenoid 39 shown in FIGS. 3 and 4
When the actuating plate 32, the base plate 12, and the head frame 15 are integrally moved toward the platen 2 based on the biasing force of the tension spring 34, the base plate 12
The upper roller 41 is engaged with the outer peripheral surface of the feed roller 42 and their movement is stopped. Therefore, a portion of the cut sheet P is held within the narrow gap between the front side of the head frame 15 and the rear side of the paper guide 6.

In this state, each dot forming body 20, print head drive motor 31 and feed drive motor (not shown)
When driven, the feed roller 42 and the platen 2 are synchronously rotated in a predetermined direction based on the drive of the feed drive motor, and the ink impregnated in the ink roller 9 that rotates following the platen 2 is transferred to the outer periphery of the platen 2. applied to the surface.

Further, based on the drive of the dot forming body 20, the printing wire 20a inside the dot forming body 20 protrudes toward the platen side, and the cut sheet P is partially pressed against the outer peripheral surface of the platen 2 by the printing wire 20a. and the cut sheet P on the opposite side to each dot forming body 20
A dot is formed on top. At this time, cut sheet P
Paper guide 6 is used for parts other than the dot forming part.
Since the ink is not pressed against the platen 2 by being blocked by the ink, there is no possibility that the ink on the platen 2 will stain the platen.

After this dot formation, the cam body 29 is rotated in a predetermined direction together with the support shaft 28 based on the drive of the print head drive motor 31.
Based on the engagement between the annular cam 30 of No. 9 and the contact pin 27 of the head frame 15, each dot forming body 20 is moved in a predetermined direction along the printing line of the platen 2 together with the head frame 15 according to the cam shape of the annular cam 30. and a predetermined dot is formed. Next, the cut sheet P is sent upward by one dot by the cooperation of the feed roller 42 and the presser roller 50, which are rotated as the feed drive motor is driven.

By repeating the above-mentioned operation, a dot matrix shape is formed while the cam body 29 is rotated half a rotation.
21 characters are printed on one line, then
The feed roller 42 and the presser roller 50 cooperate with each other to impart line feed to the cut sheet P. Note that as the head frame 15 moves laterally, each dot forming body 2
0 is responsible for printing three characters.

On the other hand, when printing on continuous paper, each of the roller supports 47, 48 and the head frame 15
If the upper part of the continuous paper is inserted from the front lower part of the frame 1 along the paper guide 6 with the paper in the position shown in FIG. The upper end of the continuous paper can be inserted through the space between the paper guide 60 and the paper guide 60 to the joint between the feed roller 42 and the presser roller 50. In this state, if you drive the feed roller 42, the continuous paper will be moved between the paper guide 6 and the head frame 1.
It can be introduced between the front side of 5 and the front side of 5.

Next, the head frame 15, each dot forming body 2
0, the platen 2, and the feed roller 42, printing can be performed on the side surface of the continuous paper on the platen side. When the continuous paper feeding is to be stopped after the printing operation is completed, each of the solenoids 52 is demagnetized so that each roller support body 47, 48 is rotated clockwise in FIG.
Based on this, the continuous paper is held between each protrusion 51 and the leaf spring 57, and each presser roller 50 is separated from the feed roller 42. Therefore, feeding of continuous paper can be stopped.

In this embodiment, when printing is performed using a narrow cut sheet P, only one of the pair of solenoids 52 is operated, and only one of the solenoids 52 is operated. Thus, the feeding of the cut sheet P can be controlled.

Further, the present invention is not limited to the configuration of the above embodiment, but it is also possible to adopt a configuration in which the dot formation bodies are arranged concentrically.

Effects of the Invention As detailed above, the present invention does not require the use of a printing ribbon, and therefore eliminates the need for troublesome ribbon attachment/detachment work, eliminates the need for a complicated ribbon feeding mechanism, and simplifies the configuration. can be manufactured at low cost. Furthermore, the printing paper is reliably supported at a distance from the platen by the guide means, so that the ink applied to the platen does not inadvertently stick to the paper, and when printing the next line, the feed roller is used to print the paper. When the paper is fed, the platen rotates in synchronization, and a new ink-coated surface appears on the platen surface corresponding to the print wire, resulting in clear prints on the print paper on the opposite side of the print wire. It has a great effect.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing the operating state of a dot matrix printer embodying the present invention, FIG. 2 is a side sectional view when inserting a cut sheet, and FIG.
4 is a partial rear view, and FIG. 5 is a partially exploded perspective view. In the figure, 2 is a platen, 6 is a paper guide that constitutes a guide means, 7 is a slit, 9 is an ink roller that is an ink application means, 15 is a head frame, 20 is a dot forming body, 20a is a printing wire, and 42 is a feeder. roller, H is a print head, and P is a cut sheet.

Claims (1)

[Scope of Claims] 1. One or more printing wires 20a disposed on the printing head H, which is reciprocated along the length direction of the platen 2, are moved toward the printing surface of the platen 2. A dot matrix printer that prints on a printing paper P guided between a platen 2 and a printing head H, comprising: an ink application means 9 for applying ink onto the surface of the platen 2; and the printing paper P. A slit 7 is provided in parallel to the path of the platen 2, and is provided near the center with a slit 7 surrounded on all sides through which the printing wire 20a can be inserted.
a guiding means 6 that guides and supports the printing paper P in the vicinity of the platen 2 so as not to contact the surface of the printing paper P; The printer is equipped with a feed roller 42 that feeds the printing paper P to the print wire 20a, and a drive means that rotates the feed roller 42 and rotates the platen 2 in synchronization with the rotation of the feed roller 42, and prints the printing paper P by the printing wire 20a. A dot matrix printer characterized in that the printing paper P is partially pressed against the surface of the platen 2 so as to print on the printing paper P on the opposite side of the printing wire 20a.