JPH11138936A - Serial printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a serial printer for attaining strengthening of a rigidity of a printer body at low cost. SOLUTION: Recesses 18A, 18B for engaging to hold ends of guide shaft 17 are formed at side plates 4A, 4B of a printer body 1. An opening 24 is formed at one side end of a top plate 23. A protrusion 22 to be engaged with the opening 24 of the plate 23 is projected on one 4B of both the plates 4A, 4B. The other side end of the plate 23 is clamped with the other plate 4A via a screw 26. And, the shaft 17 is sandwiched between the plates 4A and 4B. Thus, it can contribute to strengthening of a rigidity of the body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer which performs recording on a recording medium while reciprocating a carriage, such as a thermal printer or an ink jet printer, and more particularly to a guide shaft which serves as a guide for moving the carriage. The present invention relates to a serial printer that contributes to the rigidity of a main body.

[0002]

2. Description of the Related Art Generally, a sheet-shaped recording medium and an ink ribbon are supported in front of a platen, and a thermal head in which a plurality of heating elements are arranged and arranged along a platen together with a carriage guided by a guide shaft. The ink ribbon is fed out while being reciprocated, and the heating elements of the thermal head are selectively heated based on the recording information, thereby recording an image of a desired character or the like on paper, or without using an ink ribbon. A thermal printer that directly presses a thermal head against a thermal recording medium and selectively heats a heating element of the thermal head based on recording information, thereby recording an image of a desired character or the like on the thermal recording medium by coloring, Due to high recording quality, low noise, low cost, and easy maintenance, It has been widely used as an output device such as a processor.

In the above-described thermal printer, a guide shaft for reciprocating the carriage is generally bridged between both side plates of the printer main body.

For this reason, in this type of conventional thermal printer, both ends of a cylindrical guide shaft are formed in small diameter portions having different lengths, and the small diameters of both ends of the guide shaft are formed on the respective side plates. Part is formed coaxially with a circular hole with an inside diameter that can be inserted, first, the longer small diameter part is inserted into the circular hole of one side plate, and then the shorter small diameter part is inserted into the circular hole of the other side plate. The guide shaft is fixed to both side plates of the printer main body by inserting a washer outside the side plate into the shorter small diameter portion.

[0005]

However, in such a conventional support structure of a guide shaft in a serial printer, the guide shaft is merely supported by both side plates of the printer main body, and the guide shaft is not supported by the printer. It did not contribute to the enhancement of rigidity. For this reason, in order to enhance the rigidity of the printer main body, it is necessary to increase the strength of the parts or to increase the number of parts, which increases the cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a serial printer capable of overcoming the above-mentioned problems of the prior art and increasing the rigidity of the printer body at low cost.

[0007]

According to a first aspect of the present invention, there is provided a serial printer in which a concave portion is formed in each side plate of a printer main body to fit and hold each end of a guide shaft. An opening was formed at one end of the top plate, and a projection fitted to the opening of the top plate was protruded on one of the side plates, and the other end of the top plate was fixed to the other side plate with screws. On the point. By adopting such a configuration, the guide shaft can be sandwiched between both side plates, thereby contributing to enhancement of the rigidity of the printer main body.

A feature of the serial printer according to the second aspect is that the top plate is fixed to both side plates in a state where at least one of the side plates is bent in a direction in which an upper portion approaches the other side plate. By adopting such a configuration, the top plate holds the deflection of the side plate, thereby contributing to the enhancement of the rigidity of the printer body.

A serial printer according to a third aspect of the present invention is characterized in that a rack is fixed to a top plate, a motor is mounted on a carriage, and a pinion that meshes with the rack rotated by the motor is supported by the carriage. The point is that the carriage is moved by moving the pinion along the rack. By adopting such a configuration, the number of parts can be reduced by using the top plate, which contributes to strengthening the rigidity of the printer body, for supporting the rack for reciprocating the carriage. .

[0010]

1 and 2 show a thermal printer as an example of a serial printer according to the present invention. A printer main body 1 of the thermal printer according to the present embodiment extends in a horizontal direction. It has a substrate 2 formed by bending both side plates 4A, 4B standing upright on both sides of the bottom plate 3.

A flat platen 6 having a press-contact surface 7 on which a thermal head 5 described later is pressed upward is bridged between the side plates 4A and 4B. In the vicinity of the platen 6, a transport roller 7 for transporting a sheet (not shown) as a sheet-shaped recording medium onto the platen 6 is disposed so as to be supported by the side plates 4A and 4B. The transport roller 7 includes the side plates 4A, 4B.
A driven roller (not shown) supported by a support plate 8 fixed to the pressure contact is pressed.

A transport motor (not shown) is supported inside the one side plate 4B, and the drive of the transport motor is transmitted to the transport roller 7 via a transmission gear mechanism 9A. The paper is conveyed by the rotational driving of the driven roller.

A sheet-like frame 10 is disposed upstream of the platen 6 in a substantially horizontal sheet conveying path so as to be supported by the side plates 4A and 4B. On the other hand, a support bracket 11 is fixed on the bottom plate 3 in the vicinity of the platen 6, and a spring disposed on the frame 10 and interposed between the support plate 11 and the bottom plate 3. Members 12, 1
The press contact plate 13 urged upward by 2 is rotatably supported. An inclined guide surface 1 that is inclined obliquely downward is provided at an upstream end of the press-contact plate 13 in the sheet transport system path.
The paper feed roller 15 is pressed against the inclined guide surface 14.

The paper feed roller 15 is disposed such that both ends thereof are supported by the side plates 4A and 4B, and the motor of the paper feed roller 15 is driven by a transmission gear mechanism 9B. The paper is supplied in the direction of the platen 6 so that the paper is sandwiched between the paper feed roller 7 and the pressure contact plate 13.

The thermal head 5 is mounted on a carriage 16, and the carriage 16 is reciprocated along the platen 6 so that the thermal head 5 faces the platen 6. . For this reason, the carriage 16
A cylindrical bearing member (not shown) whose moving direction is the axial direction is fixed, and a guide shaft 17 bridged between the side plates 4A and 4B is inserted into this bearing member. Accordingly, the carriage 16 can reciprocate along the platen 6 while being guided by the guide shaft 17.

In this embodiment, the guide shaft 17 and both side plates 4 of the top plate 23 described later are used.
A and 4B are characterized by support.

That is, the guide shaft 17 is formed in a simple long cylindrical shape having no small-diameter portions at both ends, while both end portions of the guide shaft 17 are provided on the side plates 4A and 4B. Circular recesses 18A, 18B having an inner diameter that can be inserted relatively densely are formed coaxially so that each side plate 4A, 4B is plastically deformed. Accordingly, the bottom walls 19A, 19B of the recesses 18A, 18B are formed.
Project outside the side walls 4A and 4B. The guide shaft 17 has both ends fitted and held in the recesses 18A, 18B of the side plates 4A, 4B.

Further, on the top of the one side plate 4A,
A bracket 20 extending inward in the horizontal direction in which a screw hole 21 is formed is continuously provided, and the other side plate 4B is provided.
A projection 22 extending upward is provided on the top of the projection. The projection 22 has a narrow base 22a, and a wide main body 22b connected to the upper end of the base 22a.

On the other hand, an opening 24 through which the projection 22 is inserted is formed at an end of the top plate 23 bridged between the tops of the both side plates 4A and 4B on the side plate 4B side. The opening 24 has an enlarged portion 24a through which the main body 22b of the projection 22 can be inserted at the center in the longitudinal direction of the top plate 23. The constriction 2 where the base 22a of the projection 22 can fit relatively closely.
4b are continuously provided.

Further, a circular hole 25 for fixing the top plate 23 to the side plate 4A by using a screw hole 21 of the bracket 20 with a screw 26 is provided at an end of the top plate 23 on the side plate 4A side. Are formed. The distance between the screw hole 21 of the side plate 4A and the projection 22 of the side plate 4B is determined by the side plate 4B of the narrowed portion 24a of the opening 24 of the top plate 23.
It is formed slightly shorter than the distance between the side end and the circular hole 25. Therefore, in order to fix the top plate 23 to both side plates 4a and 4b, both side plates 4A and 4B must be bent inward.

On the top plate 23, a rack plate 27 having a rack 27a extending in the longitudinal direction is formed downward.
Has been fixed. On the other hand, the carriage 16 is mounted with a traveling motor (not shown) for traveling the carriage 16 and a pinion (not shown) driven to rotate by the traveling motor. The rack plate 27 meshes with the rack 27a.
Therefore, the pinion rotates by driving the traveling motor mounted on the carriage 16, and the carriage 16 moves along the guide shaft 17 so as to sequentially shift the meshing position of the top plate 23 with the rack. Will be.

Then, the transport motor is driven to rotate the paper feed roller 15, and the paper is transported until its leading end is caught between the transport roller 7 and a pressing roller (not shown). The sheet is conveyed and stopped until the predetermined position where the sheet is to be recorded is located on the platen 6 by the rotation drive of the sheet. The heating element of the thermal head 5 is recorded while moving the carriage 16 on which a ribbon cassette (not shown) is mounted while the thermal head 5 is in pressure contact with the platen 6 via the ink ribbon and the paper. The heat is selectively generated based on the information, and the ink of the ink ribbon of the ribbon cassette is transferred to the sheet to record one line. Then, the thermal head 5
Is moved away from the platen 6, the transport roller 7 is driven to position the next recording position of the sheet on the platen 6, and then the carriage 16 is moved again to record on the sheet. . In this manner, the recording on the paper can be performed by repeating the movement of the paper and the recording on the paper by the movement of the carriage 16 alternately.

In the above-described thermal transfer printer of the present embodiment, fixing of the guide shaft 17 and the top plate 23 in assembling the printer main body 1 is performed as follows.

That is, first, the guide shaft 17 is inserted into the bearing member of the carriage 16 so that the guide shaft 1
7, the carriage 16 is supported, and both ends of the guide shaft 17 are connected to the concave portions 18 of the side plates 4A and 4B.
A, 18B are fitted. And the opening 2 of the top plate 23
4 is fitted to the projection 22 of the side plate 4B, and the narrow base 24a of the projection 22 is inserted into the narrowed portion 24b of the opening 24.
Position. Then, the top plate 23 is pulled in the direction of the other side plate 4A, and the side plate 4B is bent inward.
A screw 26 is inserted into a circular hole 25 formed at the end of the third plate 3, and the screw 26 is screwed into a screw hole 21 formed in the bracket 20 of the side plate 4A. Then, in a state where the rack 27a of the top plate 23 is engaged with the pinion of the carriage 16, the top plate 23 is supported by the side plates 4A and 4B. Then, the top plate 23 and both side plates 4A, 4
When B is in the free state, the bending of the bent side plate 4B is reduced, and the side plate 4A is also bent inward.

When the upper portions of both side plates 4A and 4B bend inward in this manner, a guide shaft 17 bridged so as to be sandwiched between both side plates 4A and 4B has a gap between both side plates 4A and 4B. To constitute a part of the structure of the platen body 1 so as to restrain the
This contributes to enhancement of the rigidity of the platen body 1.

Further, a washer is not required to hold the guide shaft 17 as in the prior art.
Is also fixed with only one screw 26, so that the number of parts can be reduced and the cost can be reduced.

Further, by fixing the rack plate 27 to the top plate 23, it is possible to reduce the number of parts and contribute to cost reduction.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made as necessary. For example, the present invention is not limited to the thermal transfer printer described in the embodiment.

[0029]

As described above, according to the present invention, a recess for fitting and holding each end of the guide shaft is formed in each side plate of the printer body, and an opening is formed in one end of the top plate. At the same time, a projection that fits into the opening of the top plate protrudes from one of the both side plates, and the other end of the top plate is fixed to the other side plate with screws, so that the guide shaft is sandwiched between the two side plates. Thus, the rigidity of the printer body can be enhanced.

In a state where at least one of the side plates is bent in the direction in which the upper portion approaches the other side plate, the top plate is fixed to the both side plates, so that the top plate holds the deflection of the side plate. This can contribute to the enhancement of the rigidity of the main body.

Further, a rack is fixed to the top plate, a motor is mounted on the carriage, and a pinion that meshes with the rack rotated by the motor is supported on the carriage, and the pinion moves along the rack to move the carriage. , The number of components can be reduced by using the top plate, which contributes to the enhancement of the rigidity of the printer body, for supporting the rack for reciprocating the carriage.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a serial printer according to the present invention.

FIG. 2 is an exploded perspective view of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer main body 2 Substrate 3 Bottom plate 4A, 4B side plate 5 Thermal head 6 Platen 7 Conveyance roller 15 Feed roller 16 Carriage 17 Guide shaft 18A, 18B Depression 19A, 19B Bottom wall 20 Bracket 21 Screw hole 22 Projection 23 Top plate 24 Opening 25 Circular hole 26 Screw 27 Rack plate

Claims (3)

[Claims] 1. A serial printer that supports a guide shaft and a top plate of a carriage on both side plates of a printer body, and reciprocates a carriage equipped with a recording head along the guide shaft to perform recording on a recording medium. A recess is formed in each side plate to fit and hold each end of the guide shaft, an opening is formed in one end of the top plate, and fitted to an opening of the top plate in one of the side plates. A serial printer, wherein a projection is protruded, and the other end of the top plate is fixed to the other side plate with a screw. 2. The cereal according to claim 1, wherein the top plate is fixed to the both side plates in a state where at least one of the side plates is bent in a direction in which an upper portion approaches the other side plate. Printer. 3. A rack is fixed to the top plate,
A motor is mounted on the carriage, and a pinion that meshes with the rack rotated by the motor is supported by the carriage, and the carriage is moved by moving the pinion along the rack. The serial printer according to claim 1 or 2, wherein