JP2001315392A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer in which the head gap is sustained at a constant level by preventing a carriage shaft or a sheet feed roller from rattling at the time of printing and a sheet can be fed with high accuracy. SOLUTION: The printer 1 comprises a print head being guided by a carriage shaft 23 and a sub-carriage shaft 24 to reciprocate, a sheet feed mechanism having a first sheet feed roller, and a positioning mechanism 30 for regulating the positions of the carriage shaft 23, the sub-carriage shaft 24 and the first sheet feed roller. The positioning mechanism 30 comprises a first regulation hole 31, a second regulation hole 32, a third regulation hole 33, and a positioning spring 34 which presses the carriage shaft 23, the sub-carriage shaft 24 and the first sheet feed roller, respectively, against the first regulation hole 31, the second regulation hole 32, and the third regulation hole 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing on, for example, a roll of recording paper, and more particularly to a printer having a positioning mechanism for positioning a print head and a paper feed roller.

[0002]

2. Description of the Related Art Heretofore, in this type of printer, a recording paper in the form of a roll paper is fed by a paper feeding mechanism, and printing is performed on the recording paper while moving a print head in a paper width direction.

[0003] Such a print head is configured to be reciprocally supported by a plurality of carriage shafts. Further, these carriage shafts are provided on the main body frame so as to be parallel to the paper width direction.

On the other hand, the paper feed mechanism usually has a plurality of paper feed rollers, and these paper feed rollers keep the recording paper at a constant distance from the head surface of the print head. Are located in Here, the paper feed shafts serving as rotation support shafts of the paper feed rollers are rotatably supported by the main body frame via bearing members so as to be parallel to the paper width direction.

[0005]

By the way, in such a conventional printer, a gap is always formed between the main body frame and the carriage shaft or between the main body frame and the bearing member. During printing, the carriage shaft and paper feed shaft rattle. As a result, the distance (head gap) between the print head surface and the recording paper cannot be kept uniform. In some cases, the paper feed amount became uneven.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and an object of the present invention is to prevent rattling of a carriage shaft or a paper feed roller during printing. It is an object of the present invention to provide a printer capable of maintaining a constant head gap and feeding paper with high accuracy.

[0007]

According to the first aspect of the present invention, there is provided a recording medium having a head surface capable of printing on recording paper, a pair of a first carriage shaft and a second carriage. A print head configured to be reciprocally movable in the paper width direction by being guided by a shaft; and a paper feed roller configured to be rotatable. The recording paper is separated from the head surface by a predetermined distance by rotation of the paper feed roller. A paper feed mechanism configured to feed the paper with the first carriage unit and a first regulation unit and a second regulation unit that regulate the first carriage shaft and the second carriage shaft such that the head surface is parallel to a predetermined plane. And a third regulating unit that regulates the paper feed roller so that the recording paper fed by the paper feed mechanism is parallel to the head surface.
And the second carriage axis, respectively,
When the paper feed roller is urged by the predetermined elastic member, the paper feed roller is brought into contact with the third restriction portion by being urged by the predetermined elastic member. And a positioning mechanism configured to be in contact with the printer.

In the case of the present invention, the first carriage shaft and the second carriage shaft on the print head side are respectively urged to be pressed against the first regulating portion and the second regulating portion. The paper feed roller is pressed against the third regulating portion by being urged.

As a result, during printing, even if the first carriage shaft and the like vibrate due to the reciprocating motion of the print head, the first carriage shaft and the second carriage shaft are moved by the first regulating portion and the second carriage shaft. It does not move because it is pressed against the regulation part of. Further, even if an external force generated by, for example, friction from the recording paper is applied to the paper feed roller, the paper feed roller is pressed against the third regulating portion and rotates at that position.

Therefore, according to the present invention, the distance (head gap) between the paper feed surface (predetermined plane) formed by the paper feed roller and the head surface of the print head in the paper feed mechanism can be kept constant. At the same time, by keeping the rotation center straight line of the paper feed roller at a fixed position, the feed amount of the recording paper can be made constant.

Further, in the present invention, the positioning mechanism comprises:
An elastic member made of an elastic body, wherein the elastic member includes a main body mounted on the paper feed roller, a first arm extending from the main body in a direction capable of abutting on the first carriage shaft, and a main body. It is also effective to include a second arm extending from the second arm in a direction in which it can contact the second carriage shaft.

According to the present invention, the first carriage shaft, the second carriage shaft and the paper feed roller can be urged at once by the elastic member. Can be simplified.

Further, in the present invention, the positioning mechanism is configured such that the first regulating portion and the second regulating portion support the first carriage shaft and the second carriage shaft by point contact. It is also effective that the third regulating portion is configured to support the paper feed roller by point contact. According to the present invention, the first restricting portion, the second restricting portion, and the third restricting portion are supported by point contact, so that the first carriage shaft, the second carriage, and the like during printing. The shaft and the paper feed roller can be more effectively held at fixed positions to prevent rattling.

Further, in the present invention, the positioning mechanism supports the first carriage shaft and the second carriage shaft in substantially the same direction as gravity, and also causes the paper feed roller to have a pressing force acting on the paper feed roller. It is also effective to be configured to support in the working direction.

According to the present invention, the first carriage shaft and the second carriage shaft are supported in substantially the same direction as gravity, and the paper feed roller is moved in the direction in which the pressing force acting on the paper feed roller acts. Since the first carriage shaft, the second carriage shaft, and the paper feed roller are held at fixed positions more effectively, it is possible to prevent rattling.

Further, since the supporting members are supported in substantially the same direction as the direction of the force acting on each member, the urging force of the elastic member can be reduced, so that the elastic member can be reduced in size and the positioning mechanism itself can be reduced in size. This makes it possible to reduce the size of the printer.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a printer according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a printer according to the present embodiment. FIG. 2 is a diagram showing a schematic configuration of a main body frame on the front side of the printer. FIG. 3A is a diagram illustrating a positional relationship between the print head and the paper feed roller and the positioning spring according to the present embodiment, and FIG. 3B is a diagram illustrating a positioning mechanism according to the present embodiment. .

As shown in FIG. 1, the printer 1 of the present embodiment
Is a main body case 2 formed in a substantially box shape from, for example, resin.
have. A pair of parallel main body frames 3 is provided on both side surfaces (front and rear side surfaces in FIG. 1) in the main body case 2. Of these main body frames 3, the shape of the main body frame 3a on the front side is formed in a flat plate shape as shown in FIG. 2, while the shape of the main body frame 3b on the back side is not shown in detail, It is formed in substantially the same shape so as to be substantially symmetrical with the body frame 3a on the side.

As shown in FIG. 1, a case cover 4 is provided on the front side (left side in FIG. 1) of the main body case 2 so as to be openable and closable. The case cover 4 is fixed to a part of the parallel crank mechanism 5. Here, the parallel crank mechanism 5 includes a pair of parallel first link members 6 and second link members 7, and a first link member 6 and a second link member 7.
And the movable frame 8 disposed between the two. The first link member 6 and the second link member 7 are rotatably supported by a lower portion of the main body frame 3.
On the other hand, the movable frame 8 is rotatably supported by the first link member 6 and the second link member 7 so as to be substantially parallel to the bottom 2 a of the main body case 2. The movable frame 8 of the crank mechanism 5 is configured to move in parallel with opening and closing of the case cover 4.

On the bottom 2a of the main body case 2, a roll paper R
Is provided, and the roll paper holder 9 is disposed so as to fit inside the parallel crank mechanism 5.

The printer 1 has a paper feed mechanism 10, and this paper feed mechanism 10 is a pair of paper feed rollers capable of sandwiching the recording paper S drawn from the roll paper R,
And a third paper feed roller 13 and a fourth paper feed roller 14.

The first paper feed roller 11 is rotatably provided at a position on the back side of the main body frame 3 (a side away from the case cover 4). Here, as shown in FIG. 3A, a paper feed shaft 11a serving as a rotation support shaft of the first paper feed roller 11 is supported by the main body frame 3 via a paper bearing member 15, and the paper bearing member is provided. The position 15 is regulated by a positioning mechanism 30 described later.

On the other hand, as shown in FIG. 1, the second paper feed roller 12 is rotatably provided at a portion on the back side of the movable frame 8. Further, the second paper feed roller 12
Is configured to be able to be pressed against the first paper feed roller 11 as the movable frame 8 moves.

The fourth paper feed roller 14 is rotatably provided at the front side of the movable frame 8.
Further, when the movable frame 8 is arranged at the highest position, the fourth paper feed roller 14 is arranged such that a plane formed between the fourth paper feed roller 14 and the first paper feed roller 11 is parallel to a horizontal plane. Have been. Here, the plane formed between the first paper feed roller 11 and the fourth paper feed roller 14 is defined as:
This is a plane formed by the recording paper S fed by the paper feed mechanism 10, and in the present embodiment, is hereinafter referred to as a "recording paper surface P".

On the other hand, the third paper feed roller 13 is rotatably provided at a portion on the front side of the main body frame 3.
Further, the third paper feed roller 13 is configured to be able to be pressed against the fourth paper feed roller 14 as the movable frame 8 moves.

Although not shown in detail, the paper feed mechanism 10 transmits the power of the drive motor to the first paper feed roller 11 by a gear, and the power of the first paper feed roller 11 by this transmission. Is transmitted to the fourth paper feed roller 14 by a gear, a belt, or the like. Note that the second paper feed roller 12 and the third paper feed roller 13 are driven to rotate with the rotation of the first paper feed roller 11 and the fourth paper feed roller 14, respectively.

As shown in FIG. 1 or FIG. 3A, a printing mechanism 20 is provided at a position above the first paper feed roller 11 of the main body frame 3. This printing mechanism 20
Has a carriage head (print head) 21 that can be printed by an inkjet method, and a substantially central portion below the carriage head 21 has a flat head surface configured to be capable of discharging ink droplets. 22 are formed. The carriage head 21 is supported by a pair of carriage shafts (first carriage shaft) 23 and a sub-carriage shaft (second carriage shaft) 24 so as to be able to reciprocate in the paper width direction. The carriage shaft 23 and the sub-carriage shaft 24 are provided between the main body frame 3a and the main body frame 3b, and their positions are regulated by a positioning mechanism 30 described later.

Here, a bearing member 25 capable of bearing the carriage shaft 23 is provided on the rear side (right side in FIG. 3) of the carriage head 21. The carriage shaft 23 fits into the bearing member 25 of the carriage head 21 so as to be arranged in parallel with the printing direction in the head surface 22. A holding portion 26 which can hold the sub-carriage shaft 24 from above and below the sub-carriage shaft 24 is formed at the front side of the carriage head 21. The sub-carriage shaft 24 can be moved relative to the carriage shaft 23 on a plane parallel to the head surface 22 by being sandwiched between the holding portions 26 of the carriage head 21.

As shown in FIG. 3B, the positioning mechanism 30 of the present embodiment has a first regulating hole (first regulating portion) 3.
1, a second regulating hole (second regulating portion) 32, a third regulating hole (third regulating portion) 33, and a positioning spring (elastic member) 34.

As shown in FIG. 2, the first regulating hole 31 is
The main body frame 3 a is provided at a position where the carriage shaft 23 is to be supported, in such a size as to be able to contact the carriage shaft 23.

The second restricting hole 32 is provided at a portion of the main body frame 3a where the sub-carriage shaft 24 is to be supported, and has a size capable of contacting the sub-carriage shaft 24.

The third restriction hole 33 is provided in the main frame 3a.
The first paper feed roller 11 is provided at a position where the paper bearing member 15 of the first paper feed roller 11 is to be supported, with a size capable of abutting the paper bearing member 15. Here, in the present embodiment, a known cylindrical bearing member with a flange is used as the paper bearing member 15.

On the other hand, although not shown in detail, a positioning mechanism having the same symmetrical shape as the positioning mechanism 10 on the body frame 3a side is provided on the body frame 3b on the back side in FIG.

As shown in FIG. 3B, the first regulating hole 3
1 is formed in a shape having a first vertical regulating edge 31a extending vertically at a rear end of the main body frame 3a and a first horizontal regulating edge 31b extending horizontally at a lower end. Have been. On the other hand, the second regulating hole 32
Is formed into a shape having a second vertical regulating edge 32a extending vertically at the front end of the main body frame 3a and a second horizontal regulating edge 32b extending horizontally at the lower end. Have been.

Here, the first vertical regulating edge 31a is for determining the positional relationship in the paper feed direction between the head surface 22 and the recording paper surface P on the paper feed mechanism 10 side by the carriage shaft 23. The one horizontal regulating edge 31b is for keeping the carriage shaft 23 at a constant distance from the recording paper surface P.

The second vertical regulating edge 32a keeps the sub-carriage shaft 24 at a constant distance from the carriage shaft 23 to be regulated by the first vertical regulating edge 31a and the first horizontal regulating edge 31b. The second horizontal regulating edge 31b positions the sub-carriage shaft 24 with respect to the carriage shaft 23 so that the head surface 22 is parallel to the recording paper surface P on the paper feed mechanism 10 side. is there.

On the other hand, the third regulating hole 33 is formed at the upper end of the main body frame 3a by the first regulating hole 31 and the second regulating hole 31.
Symmetrical vertical center line between the regulating holes 32,
It is formed in a shape having a first inclination regulating edge 33a on the first regulating hole 31 side and a second inclination regulating edge 33b on the second regulating hole 32 side extending diagonally downward on both sides. .

The first inclination regulating edge 33a and the second inclination regulating edge 33b are connected to the carriage shaft 23 to be regulated by the first regulating hole 31 and the sub-carriage shaft 24 to be regulated by the second regulating hole. On the other hand, it is for determining the first paper feed roller 11 at a fixed position.

As shown in FIGS. 3A and 3B, a torsion coil spring is used as the positioning spring 34 in this embodiment.

The coil portion 34a of the positioning spring is formed so that its inner diameter is slightly larger than the outer diameter of the cylindrical portion of the paper bearing member 15. The first arm 34 a of the positioning spring 34 is formed to have a length that can contact both the cylindrical portion of the paper bearing member 15 and the carriage shaft 23. On the other hand, the second arm portion 34c of the positioning spring 34 moves the paper bearing member 1 in a direction in which the second arm portion 34c
5 is formed to a length that can contact both the cylindrical portion 5 and the sub-carriage shaft 24.

The positioning spring 34 is connected to the coil 3
4a is attached to the cylindrical portion of the paper bearing member 15, whereby the first arm portion 34a and the second arm portion 34b are bent in the closing direction, respectively, so that the carriage shaft 23
And the sub-carriage shaft 24.

In this embodiment having such a configuration, as shown in FIGS.
The first arm 34b abuts on the carriage shaft 23, whereby the carriage shaft 23 is urged obliquely downward on the back side as shown in the direction of arrow A. The positioning spring 3
The sub-carriage shaft 24 is urged obliquely downward on the front side, as indicated by arrow B, by the contact of the second arm 34c of No. 4 with the sub-carriage shaft 24. On the other hand, the coil portion 34a of the positioning spring 34 is moved upward in the direction of arrow C by the force returning to the direction in which the first arm portion 34a and the second arm portion 34b open, and comes into contact with the paper bearing member 15. Thereby, the paper bearing member 15 is urged in the arrow C direction.

In the case described above, since the carriage shaft 23 and the sub-carriage shaft 24 are urged in directions away from each other, the carriage shaft 23 and the sub-carriage shaft 24 always have the first vertical regulating edge 31a and the second vertical regulating edge 32a. Pressed with point contact. Further, the carriage shaft 23 and the sub-carriage shaft 24
And the first paper feed roller 11 are urged in a direction approaching each other, so that each of the first
And the second horizontal regulating edge 32b and the first inclination regulating edge 33a
And the second inclination regulating edge 33b is always pressed with point contact.

As a result, the distance between the carriage shaft 23 and the sub-carriage shaft 24 is kept constant, and the distance between the carriage shaft 23 and the sub-carriage shaft 24 and the first paper feed roller 11 is kept constant. Because
Head surface 22 of carriage head 21 and paper feed mechanism 10
Is arranged in parallel with the recording paper surface P on the side.

When printing, the carriage head 21
Of the carriage shaft 23 and the sub-carriage shaft 2
4, the carriage shaft 23 and the sub-carriage shaft 24 are always pressed against the first restriction hole 31 and the second restriction hole 32 by the positioning spring 34, so that the carriage shaft 23 and the sub-carriage shaft 24 does not move from a position determined by the positioning mechanism 30.

As a result, the carriage head 21 reciprocates in the paper feed direction while maintaining the head surface 22 at a constant distance (head gap G) from the recording paper surface P on the paper feed mechanism 10 side. Particularly, in this case, the carriage head 21 smoothly moves on the carriage shaft 23 and the sub-carriage shaft 24 which are kept parallel because the holding portion 26 movably supports the sub-carriage shaft 24.

On the other hand, when feeding the paper, the first paper feed roller 1
1 is applied to the paper bearing member 1 of the first paper feed roller 11 even if an external force generated due to, for example, friction from the recording paper S is applied.
5 is constantly pressed against the third regulating hole 33 by the positioning spring 34, so that the first paper feed roller 11
It rotates at a position determined by the positioning mechanism 30.

As a result, the first paper feed roller 11 rotates with the fourth paper feed roller 14 keeping the recording paper surface S parallel to the horizontal plane and keeping the rotation center straight line constant. In this case, the recording paper S and the first paper feed roller 1
Since the speed component in the paper feed direction on the tangent line to 1 is always constant, the first paper feed roller 11 feeds a certain amount of the recording paper S in the paper feed direction.

As described above, according to the present embodiment,
Since the carriage shaft 23 and the sub-carriage shaft 24 on the side of the carriage head 21 and the first paper feed roller 11 of the paper feed mechanism 10 are positioned by the positioning mechanism 30 and rattling that occurs during printing is prevented. The paper can be fed with high accuracy while the head gap G is kept constant.

In particular, the carriage shaft 23 and the sub-carriage shaft 24 on the side of the carriage head 21 are connected to the first regulating holes 31.
With the paper bearing member 15 of the first paper feed roller 11 inserted into the third restriction hole 33 and the positioning spring 34 attached, the head gap G Has the advantage that it is not necessary to prepare the head gap G.

Further, according to the present embodiment, the positioning spring 34 allows the carriage shaft 23 and the sub-carriage shaft 2
4 and the first paper feed roller 11 are collectively biased, so that the number of parts is reduced and the positioning mechanism 30 is pressed.
The structure itself can be simplified. Further, according to the present embodiment, each of the carriage shaft 23, the sub-carriage shaft 24, and the paper bearing member 15 of the first paper feed roller 11 is provided with the first vertical regulating edge 31a and the first horizontal regulating edge 3a.
1b, between the second vertical regulating edge 32a and the second horizontal regulating edge 32b, and between the first inclination regulating edge 33a and the second inclination regulating edge 33b so as to be supported by point contact. Therefore, during printing, the carriage shaft 23, the sub-carriage shaft 24, and the first paper feed roller 11 can be more effectively held at fixed positions to prevent rattling.

Further, according to the present embodiment, each of the carriage shaft 23 and the sub-carriage shaft 24 is supported by the first horizontal regulating edge 31a and the second horizontal regulating edge 32b substantially in the same direction as the direction of gravity. The first paper feed roller 11 is provided with a first inclination regulating edge 33a provided in substantially the same direction as the direction pressed by the second paper feed roller 12.
And the second inclination restricting edge 33b, the carriage shaft 23, the sub-carriage shaft 24,
The first paper feed roller 11 can be more effectively held at a fixed position to prevent rattling.

The present invention is not limited to the above-described embodiment, but can be variously modified.

For example, in the above-described embodiment, the carriage head 21 configured to perform printing by the ink jet system is used, but the positioning mechanism according to the present invention is not limited to this. The present invention can also be applied to a carriage head configured to perform printing. In this case, similarly to the above-described embodiment, the head gap, which is the distance between the impact surface and the recording paper surface, can be made constant.

In the above embodiment, a torsion coil spring is used as the positioning spring 34. However, the present invention is not limited to this, and two or three springs can be used regardless of the type. However, from the viewpoint of the number of parts, it is preferable to carry out the embodiment as described above.

[0057]

As described above, according to the present invention, the paper can be fed with high accuracy by the positioning mechanism while the head gap is kept constant.

Further, according to the present invention, by using the positioning spring, the number of components can be reduced, and the positioning mechanism itself can be simplified.

According to the present invention, since the positioning mechanism is supported by point contact, it is possible to more effectively hold the positioning mechanism at a fixed position and prevent rattling.

According to the present invention, since the positioning direction is set to be substantially the same as the direction in which the force acts, it is possible to more effectively hold at a fixed position and prevent rattling.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a printer according to an embodiment.

FIG. 2 is a diagram showing a schematic configuration of a main body frame on the front side of the printer.

FIG. 3A is a diagram illustrating a positional relationship among a print head, a paper feed roller, and a positioning spring according to the present embodiment. (B): It is a figure which shows the positioning mechanism of this Embodiment.

[Explanation of symbols]

 Reference Signs List 10 paper feed mechanism 11 first paper feed roller 21 carriage head (print head) 22 head surface 23 carriage axis (first carriage axis) 24 sub-carriage axis (second carriage axis) 30 positioning mechanism 31 first regulation Hole (first regulating portion) 32 Second regulating hole (second regulating portion) 33 Third regulating hole (third regulating portion) 34 Positioning spring (elastic member)

Claims (4)

[Claims] A print head having a head surface capable of printing on recording paper and configured to be reciprocally movable in a paper width direction by being guided by a pair of a first carriage shaft and a second carriage shaft; A paper feed roller having a paper feed roller configured to be rotatable, and a paper feed mechanism configured to feed the recording paper at a predetermined interval from the head surface by rotation of the paper feed roller; The first so as to be parallel to the plane of
A first regulating unit and a second regulating unit that regulate the carriage shaft and the second carriage shaft, and the paper feed roller so that the recording paper fed by the paper feed mechanism is parallel to the head surface. A third regulating portion for regulating, wherein the first carriage shaft and the second carriage shaft are
Each of the paper feed rollers is urged by a predetermined elastic member to contact the first restriction portion and the second restriction portion by being urged by a predetermined elastic member. 3. A printer comprising: a positioning mechanism configured to come into contact with the regulating portion of No. 3. 2. An elastic member of the positioning mechanism comprises: a main body which can be mounted on the paper feed roller;
And a second arm extending from the main body in a direction capable of abutting on the second carriage shaft. Item 1. The printer according to Item 1. 3. The positioning mechanism according to claim 1, wherein the first restricting portion and the second restricting portion support the first carriage shaft and the second carriage shaft by point contact. 3. The printer according to claim 1, wherein the third regulating unit is configured to support the paper feed roller by point contact. 4. 4. A regulating portion of the positioning mechanism is configured to support the first carriage shaft and the second carriage shaft in substantially the same direction as the direction of gravity, and to control the paper feed roller. 3. The printer according to claim 1, wherein the printer is configured to be supported in substantially the same direction as the pressing force acting on the paper feed roller.