JP2004114365A - Platen gap adjuster and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentric cam system platen gap adjuster and a recorder capable of moving a recording head through a simple arrangement. <P>SOLUTION: The recorder 10 comprises a spring 60 for urging a recording head 18 to the carriage guide shaft 40 side with respect to a carriage 19, and an eccentric cam 70 fixed to a carriage guide shaft 24 and regulating movement of the recording head 18 to the urging side of the spring 60. The eccentric cam 70 is turned by turning the carriage guide shaft 24 and the recording head 18 is moved to the platen 21 side or the opposite side (in the direction shown by α in Figure). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a platen gap adjusting device and a recording device.
[0002]
[Prior art]
A dot impact printer is known as a printer that performs printing on continuous paper or copy-type paper. A dot impact printer is a printer that performs printing by driving a plurality of recording wires while moving a recording head in the width direction of recording paper.
[0003]
A dot impact printer generally includes a PG adjustment mechanism that adjusts a distance between a recording head and a platen (platen gap, hereinafter, referred to as “PG”). This allows the dot impact printer to adjust the distance between the recording head and the recording paper to a constant value even when printing on continuous paper or copy paper having different thicknesses.
[0004]
By the way, the PG adjusting mechanism includes an eccentric cam system in which a carriage guide shaft is moved in the front-rear direction with respect to a platen by rotation of an eccentric cam, thereby adjusting PG (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-5-92638 (page 2-3, FIG. 1, FIG. 2)
[0006]
[Problems to be solved by the invention]
However, in the conventional eccentric cam type PG adjusting mechanism, the eccentric cams abut on both sides of the carriage guide shaft, and the carriage guide shaft is moved in parallel by the rotation of the eccentric cam. Each of them requires a large number of parts, and this mechanism is protruded to both sides to increase the width of the printer.
[0007]
Further, if there is any deviation in the shape and angle of the eccentric cams on both sides, the PG changes according to the position of the recording head, and there is a problem that the printing quality changes on the left and right sides of the recording paper.
[0008]
Further, since the recording head is moved together with the carriage guide shaft, rigidity is required for a frame, a spring, and the like for guiding the movement of the carriage guide shaft, which is disadvantageous in reducing the cost of parts and reducing the weight.
[0009]
The present invention has been made in view of the above-described circumstances, and has as its object to provide an eccentric cam type platen gap adjusting device and a recording device that can move a recording head with a simple configuration.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 has a recording head held on a carriage supported by a carriage guide shaft and arranged with a space between the platen and the recording head. In a platen gap adjusting device for adjusting an interval, the recording head is held movably with respect to the carriage, and has a moving unit for moving the recording head in the direction of the platen or in the direction opposite thereto. And According to this configuration, the recording head is held movably in the direction of the platen with respect to the carriage, and moved by the moving means in the direction of the platen or in the direction opposite thereto, so that the recording head can be moved with a simple configuration. it can.
[0011]
According to a second aspect of the present invention, in the configuration of the first aspect, a carriage guide shaft for supporting the carriage is provided, and the moving unit attaches the recording head to a platen side or an opposite side thereof. Urging means for urging, an eccentric cam attached to the carriage guide shaft, for restricting the movement of the recording head against the urging force of the urging means, and rotating the eccentric cam to rotate the recording head. Rotating means for moving in the direction of the platen or in the direction opposite thereto. According to this configuration, the moving unit includes an urging unit that urges the recording head to the platen side or the opposite side, an eccentric cam that regulates the movement of the recording head against the urging force of the urging unit, The recording head can be moved with a simple configuration because it is constituted by the rotating means for rotating the cam.
[0012]
According to a third aspect of the present invention, in the configuration of the second aspect, the eccentric cam rotates integrally with the carriage guide shaft and moves in a longitudinal direction of the carriage guide shaft. I do. According to this configuration, even if the eccentric cam moves to any position in the axial direction of the carriage guide shaft, the recording head can be moved by the rotation of the eccentric cam.
[0013]
According to a fourth aspect of the present invention, in the configuration of the first aspect, the moving unit is attached to the pinion attached to the carriage guide shaft, and attached to the recording head, and engages with the pinion. A rack and a rotating means for rotating the pinion to move the recording head in the direction of the platen or in the direction opposite thereto. According to this configuration, the moving unit includes the pinion attached to the carriage guide shaft, the rack attached to the recording head, and the rotating unit that rotates the pinion. Can be moved.
[0014]
According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the moving unit includes an urging unit for urging the recording head to a platen side or an opposite side thereof. . According to this configuration, it is possible to reliably prevent the recording head from moving by the backlash between the rack and the pinion.
[0015]
According to a sixth aspect of the present invention, in the configuration according to the fourth or fifth aspect, the pinion rotates integrally with the carriage guide shaft and moves in the axial direction of the carriage guide shaft. And According to this configuration, even if the pinion moves to any position in the longitudinal direction of the carriage guide shaft, the recording head can be moved by the rotation of the pinion.
[0016]
According to a seventh aspect of the present invention, there is provided a recording apparatus including the platen gap adjusting device according to any one of the first to sixth aspects. According to this configuration, the recording apparatus can move the recording head with a simple configuration.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below show one aspect of the present invention, and do not limit the present invention, and can be arbitrarily changed within the scope of the present invention.
(1) Embodiment (1.1) First Embodiment FIG. 1 shows a printer main body 11 of a dot impact printer (hereinafter, referred to as a printer) 10 according to a first embodiment of the recording apparatus of the present invention and its peripheral configuration. FIG. FIG. 2 is a side sectional view of FIG.
[0018]
The printer 10 records an image such as a character composed of dots by ejecting a large number of recording wires from the recording head 18 and striking an ink ribbon on the recording paper S. Here, the recording paper S is a passbook, a postcard, an envelope, and the like, in addition to plain paper such as cut sheet (including cut copy paper) and continuous paper (including continuous copy paper).
[0019]
The printer 10 includes a printer body 11, a push tractor unit 12 and a discharge unit 13 detachably mounted on the printer body 11, and a sheet supply guide 34 (see FIG. 2) also detachably mounted on the printer body 11. And an upper case (not shown) and a lower case (not shown) that cover the upper and lower portions of the printer main body 11, respectively.
[0020]
The printer body 11 includes a base frame 14 as a body frame, a sheet guide frame 15 (see FIG. 2), a left side frame 16 and a right side frame 17, a print mechanism unit 20 including a recording head 18 and a carriage 19. And a sheet transport mechanism 23 having a sheet guide 22 and a pinch roller 25 (see FIG. 2).
[0021]
As shown in FIG. 2, the base frame 14 and the seat guide frame 15 are arranged so as to be continuous, and the left side frame 16 and the right side frame 17 are fixed to both ends of each of the frames 14 and 15, respectively. . Between the left side frame 16 and the right side frame 17, carriage guide shafts 24 and 40 and a platen 21 are rotatably bridged. 1 and 2, the carriage guide shaft 40 is hidden by other components. The seat guide 22 is disposed between the left side frame 16 and the right side frame 17 and fitted to the seat guide frame 15. A tractor unit mounting portion (not shown) for mounting the push tractor unit 12 and the discharging unit 13 and a discharging unit mounting portion (not shown) are provided on the rear and upper portions of the left side frame 16 and the right side frame 17, respectively. ) Is provided.
[0022]
The push tractor unit 12 sends out continuous paper as the recording paper S to the sheet transport mechanism 23. Further, the sheet supply guide 34 sends out the cut sheets as the recording sheets S one by one (in the case of continuous cut sheets, one by one) to the sheet transport mechanism 23. The discharge unit 13 pulls out continuous paper or cut sheet from the sheet transport mechanism 23 to the outside of the printer 10.
[0023]
That is, the continuous paper is guided by the sheet guide 22 of the sheet transport mechanism 23 by the action of the pins 27 of the tractor belt 26 by the rotation of the tractor belt 26 of the push tractor unit 12, and the sheet guide 22 and the platen 21 The sheet is conveyed to the front of the platen 21 via the sheet conveying path 28 therebetween. On the other hand, the cut sheet is guided one by one (or one by one) from the sheet supply guide 34 to the sheet guide 22, and is supplied to the front of the platen 21 via the sheet conveyance path 28. The continuous paper or cut sheet is conveyed to the discharge unit 13 by rotation of the discharge roller 29 after characters are recorded by the recording head 18.
[0024]
The recording head 18 includes a number of recording wires, and selectively protrudes the recording wires under the control of a head driving unit (not shown). An ink ribbon cassette 31 is detachably mounted between the left side frame 16 and the right side frame 17 so as to face the base frame 14. The ink ribbon of the ink ribbon cassette 31 is drawn between the recording head 18 and the platen 21. Thereby, the ink of the ink ribbon can be transferred to the recording paper S on the platen 21 by the projection of the recording wire.
[0025]
Further, between the base frame 14 and the sheet guide frame 15, a bottom sheet supply port 32 for supplying continuous paper as the recording paper S to the sheet transport path 28 is formed.
[0026]
FIG. 3 is a side sectional view schematically showing the recording head 18 and its peripheral configuration. FIG. 4 is a sectional view taken along line AA of FIG. The carriage 19 moves the recording head 18 in the width direction of the recording paper S and holds the recording head 18 so as to be movable toward the platen 21.
[0027]
Hereinafter, specifically, the carriage 19 is supported movably in the axial direction of the carriage guide shafts 24 and 40. Here, among the carriage guide shafts 24 and 40, the carriage guide shaft 24 is rotatably inserted into the carriage 19 by bearings 42 and 43.
[0028]
Further, the carriage 19 is moved in the axial direction of the carriage guide shafts 24 and 40 by a carriage drive motor (not shown) via a timing belt mechanism (not shown), and is moved in the parallel direction of the platen 21 (FIG. 1). In the direction perpendicular to the plane of the drawing). Thus, during printing, the recording head 18 can be reciprocated in the printing direction (column direction) of the recording paper S by reciprocating the carriage 19 in the direction parallel to the platen 21.
[0029]
The carriage 19 holds the holder 50 of the recording head 18 so as to be movable in the front-rear direction of the platen 21 (α direction in the drawing). The holder 50 is pulled toward the carriage guide shaft 40 by a spring (biasing means) 60, whereby the holder 50 is positioned at a position where the lower extension 55 contacts the eccentric cam 70.
[0030]
In the present embodiment, the case where the holder 50 is urged by the coil spring 60 as a tension spring has been described, but various elastic members such as a compression spring, a leaf spring, and rubber may be used. Further, the case has been described in which the holder 50 is urged toward the carriage guide shaft 40 by this kind of urging means, and the movement to the opposite side (the platen 21 side) is regulated by the eccentric cam 70. 60), the holder 50 may be biased to the opposite side (to the platen 30), and the eccentric cam 70 may restrict the movement of the holder 50 toward the carriage guide shaft 40.
[0031]
The eccentric cam 70 is a disk whose axis is located at a position different from the axis of the carriage guide shaft 24, and rotates integrally with the carriage guide shaft 24. In the present embodiment, the eccentric cam 70 is integrally formed at the center of a cylindrical member (hereinafter, referred to as a cylindrical member) 75, and the cylindrical member 75 is provided between the bearings 42 and 43 of the carriage guide shaft 24. , So as to be located substantially at the center of the bearings 42 and 43. Further, the cylindrical member 75 is formed with a convex portion that fits into the key groove 45 formed in the axial direction of the carriage guide shaft 24, whereby the eccentric cam 70 rotates integrally with the carriage guide shaft 24. In addition, the carriage guide shaft 24 can be moved in the axial direction. Thus, the eccentric cam 70 also moves as the carriage 19 moves in the axial direction of the carriage guide shaft 24.
[0032]
Therefore, regardless of the position of the carriage 19 on the carriage guide shaft 24, when the eccentric cam 70 is rotated by the rotation of the carriage guide shaft 24, the axis of the carriage guide shaft 24 and the lower extension 55 of the holder 50 Is changed, and the recording head 18 can be moved to the platen 21 side or the opposite side with respect to the carriage 19. Thereby, the distance (PG) between the recording head 18 and the platen 21 can be changed.
[0033]
Here, when performing this PG adjustment automatically, although not shown, the carriage guide shaft 24 is rotated by a pulse motor via a speed reduction mechanism, and a code plate attached to the pulse motor shaft and The rotation angle of the carriage guide shaft 24 (or the eccentric cam 70) may be detected by an encoder (detection unit) including an interrupter. Then, a control unit which is a control center of the printer 10 for PG adjustment or the like may drive the pulse motor based on the rotation angle detected by the encoder to automatically perform PG adjustment.
[0034]
On the other hand, when performing PG adjustment manually, the carriage guide shaft 24 is configured to be able to be rotated by a manual lever via a speed reduction mechanism, and the user of the printer 10 moves the manual lever to set PG to a desired value. It may be adjusted.
[0035]
As described above, in the printer 10 of the present embodiment, the recording head 18 is held movably toward the platen 21 with respect to the carriage 19, and the PG can be changed by the rotation of the eccentric cam 70.
[0036]
In the printer 10, the mechanism for moving the recording head 18 to the platen 21 is disposed in the carriage 19, and therefore, compared with the conventional configuration in which the eccentric cam 70 and the like are provided on both sides of the carriage guide shaft 24, Can be reduced. Further, since this mechanism does not protrude to both sides of the printer main body 11, the width of the printer can be reduced.
[0037]
In the above-described conventional configuration, if the shapes and angles of the eccentric cams on both sides are misaligned, the PG changes according to the position of the carriage 19, but in the present printer 10, the PG changes regardless of the position of the recording head 18. , PG can be constant.
[0038]
The printer 10 is configured to move the recording head 18 in the front-rear direction of the platen 21 with respect to the carriage 19, so that only the recording head 18 and its holder 50 need to be moved. This is advantageous in reducing the cost of parts and reducing the weight as compared with the above-described conventional configuration in which the recording head 18 is moved.
[0039]
(1.2) Second Embodiment The printer 10A according to the second embodiment is greatly different from the printer 10 according to the first embodiment in that the printer 10 according to the first embodiment uses an eccentric cam 70 to form a recording head. The difference is that the recording head 18 is moved by using a rack and pinion, while the recording head 18 is moved to the platen 21 side. Hereinafter, for convenience of explanation, the same parts are denoted by the same reference numerals and described.
[0040]
FIG. 5 is a side view schematically showing the recording head 18 and its peripheral configuration of the printer 10A according to the second embodiment. FIG. 6 is a sectional view taken along line BB of FIG.
[0041]
In the printer 10A, a pinion (gear) 80 is mounted on the carriage guide shaft 24 instead of the eccentric cam 70. The pinion 80 is also provided so as to rotate integrally with the carriage guide shaft 24 and to be movable in the axial direction of the carriage guide shaft 24 along the key groove 45. Thus, the pinion 80 moves with the movement of the carriage 19 in the axial direction of the carriage guide shaft 24.
[0042]
In addition, the holder 50A of the recording head 18 is provided with a rack 90 that engages with the pinion 80 instead of the lower extension 55. Therefore, when the pinion 80 is rotated by the rotation of the carriage guide shaft 24, the recording head 18 is moved by the rack 90 in the front-rear direction of the platen 21 with respect to the carriage 19. Thereby, the distance (PG) between the recording head 18 and the platen 21 can be changed.
[0043]
As described above, in the printer 10A according to the second embodiment, the recording head 18 is held movably toward the platen 21 with respect to the carriage 19, and the PG can be changed by rotating the pinion 80. Also in the printer 10A, a mechanism for moving the recording head 18 to the platen 21 side can be arranged in the carriage 19, similarly to the printer 10 according to the first embodiment. , And the width of the printer can be reduced.
[0044]
In the second embodiment, the spring (biasing means) 60 can reliably prevent the recording head 18 from moving by the backlash between the rack 90 and the pinion 80. However, when the backlash is practically negligible, the spring (biasing means) 60 may be omitted.
[0045]
In each of the above embodiments, the case where the present invention is applied to a dot impact printer has been described. However, the present invention can be widely applied to various printers that change the distance between a recording head and a platen. Although the case where a round platen is used as the platen 21 has been described, it is needless to say that the present invention can be applied to a case where a flat platen is used.
[0046]
【The invention's effect】
As described above, according to the present invention, in the recording apparatus of the eccentric cam system, the recording head can be moved with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a printer main body of a printer according to a first embodiment of the present invention and a peripheral configuration thereof.
FIG. 2 is a side sectional view of FIG.
FIG. 3 is a side cross-sectional view around a recording head of the printer.
FIG. 4 is a sectional view taken along line AA of FIG. 3;
FIG. 5 is a side sectional view around a recording head of a printer according to a second embodiment of the present invention.
FIG. 6 is a sectional view taken along line BB of FIG. 5;
[Explanation of symbols]
10, 10A Printer 11 Printer main body 18 Recording head 19 Carriage 21 Platen 24 40 Carriage guide shaft 50 Holder 70 Eccentric cam 80 Pinion 90 Rack S Recording paper

Claims (7)

A platen gap adjustment device that has a recording head that is held by a carriage supported by a carriage guide shaft and that is arranged with a gap between the recording head and the platen, and that adjusts the gap between the recording head and the platen.
The recording head is movably held with respect to the carriage,
A platen gap adjusting device, comprising a moving means for moving the recording head in the direction of the platen or in the direction opposite thereto. The moving means,
Urging means for urging the recording head to the platen side or the opposite side,
An eccentric cam attached to the carriage guide shaft and for restricting movement of the recording head against an urging force of the urging means;
2. The platen gap adjusting device according to claim 1, further comprising: a rotating unit configured to rotate the eccentric cam to move the recording head in a platen side direction or a direction opposite thereto. The platen gap adjustment device according to claim 2, wherein the eccentric cam rotates integrally with the carriage guide shaft and moves in a longitudinal direction of the carriage guide shaft. The moving means,
A pinion attached to the carriage guide shaft,
A rack attached to the recording head side and engaged with the pinion;
2. The platen gap adjusting device according to claim 1, further comprising: a rotation unit configured to rotate the pinion to move the recording head in a platen side direction or a direction opposite thereto. The platen gap adjusting device according to claim 4, wherein the moving unit includes a biasing unit that biases the recording head to a platen side or an opposite side thereof. The platen gap adjusting device according to claim 4, wherein the pinion rotates integrally with the carriage guide shaft and moves in a longitudinal direction of the carriage guide shaft. A recording apparatus comprising the platen gap adjusting device according to claim 1.

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