JPH01182077A - Recorder - Google Patents

Abstract

PURPOSE:To reduce the minimum bottom margin of a sheet and contrive a higher degree of freedom of printing format, by a contruction wherein a small diameter pinch roller is rotatably fitted to the tip of a roller support member mounted on a main body of a recorder, and the roller support member is energized toward a sheet-feeding roller by a roller-pressing spring. CONSTITUTION:A small diameter pinch roller 10 located at a position on a sheet-feeding roller 1 adjacent to a head surface 7 is rotatably fitted to the tip of a roller support member 12 oscillatably mounted on a main body of a recorder through a pin 11. The pinch roller 10 is pressed against the peripheral surface of the sheer-feeding roller 1 by a rollerpressing spring 14 stretched between the support member 12 and the main body. Since the small diameter pinch roller 10 pressed against the sheet feeding roller 1 is provided on the direct upstream of the head surface 7 of a recording head 6, the bottom margin, or non-printable range, of a recording sheet at the time of separation of the sheet from the pinch roller 10 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording device such as a printer or a facsimile, and more particularly to an arrangement structure of a pinch roller that is pressed against a sheet feed roller of the recording device.

[Conventional technology]

In recording devices such as printers and facsimile machines, a sheet feed motor is used as a sheet feeding means to feed a supplied sheet (recording medium such as paper or a thin plastic plate) between the recording head and the platen (printing section). A structure in which a rotatable pinch roller is pressed against the circumferential surface of a sheet feeding roller so that it can be separated is used.

As a platen for backing up sheets in the recording section,
In addition to providing another flat platen, the peripheral surface of the sheet feeding roller may also be used.

Furthermore, printing is also performed while applying tension to the sheet by pulling the sheet that has passed through the recording section with a discharge roller provided on the downstream side (usually near an upper sheet discharge port).

[Problem that the invention seeks to solve]

By the way, in conventional recording apparatuses, the distance from the pinch roller (the roller closest to the recording head when provided at multiple positions) that is pressed against the sheet feeding roller to the head surface of the recording head cannot be made very small due to its structure.

For this reason, the range in which sheet feeding cannot be controlled at the rear end of the sheet, that is, the bottom margin of the sheet becomes large, which is inconvenient for printing such as printing postcards and printing addresses on envelopes.

In addition, when the trailing edge of the sheet comes off the pinch roller, the tension from the ejection roller causes the feed pitch to suddenly widen, resulting in printing defects such as white streaks in solid printing and extended character printing. It was happening.

[Failure to solve the problem]

The present invention has been made in view of the above-mentioned problems of the prior art, and it is an object of the present invention to provide a recording device that can sufficiently reduce the bottom margin and improve the freedom of print arrangement on a sheet. .

In the present invention, a small-diameter pinch roller is rotatably attached to the tip of a roller support member attached to an apparatus main body, and a roller pressure contact spring biases the roller support member toward a sheet feeding roller. The above object is achieved by a configuration in which the pinch roller is brought into pressure contact with a portion of the sheet feed roller adjacent to the recording head.

In the above configuration, the carriage is further supported so as to be movable in the front and back direction, and the carriage is moved rearward by the movement of the roller support member according to the sheet thickness, thereby uniformly adjusting the head gap. It is preferable to do so.

〔Example〕

The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a main part of a recording apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram schematically showing the positional relationship between the small-diameter pinch roller and the head surface in FIG. 1. be.

In FIG. 1, 1 on the lower circumference of the sheet feed roller 1
Separable pinch rollers 2.2 are pressed against one or two locations, and by rotating the sheet feed roller 1 in the direction of arrow B, the sheet fed from the direction of arrow B is fed to the printing section.

A paper pan 13 is installed below the sheet feed roller 1 with a predetermined gap therebetween to form a sheet passage.

A guide shaft 3 and a guide rail 4 are installed on the left side (front side) of the sheet feed roller 1 in parallel thereto, and a carriage 5 that reciprocates left and right within the recording device along these guides 3.4 carries a recording device. Head 6 is installed.

A platen (fixed platen or flat platen) 8 is installed at a position facing the front surface (head surface) 7 of the recording head 6 with a predetermined interval (head gap) therebetween. The illustrated platen 8 also forms a sheet guide surface extending upward, and in the case of an inkjet recording apparatus, may also serve as a fixing heater for drying ink.

A discharge roller 9 is disposed near the upper end of the platen 8, which pulls the sheet sent to the recording section (between the head surface 7 and the platen 8), applies tension to feed the sheet, and also removes the recorded sheet. It is configured to be discharged to the outside.

However, a small-diameter pinch roller IO is arranged at a position adjacent to the head surface 7 of the sheet feed roller l.

This small-diameter pinch roller 10 has a roller support member 12 that is swingably attached to the main body of the device via a pin (fulcrum) 11.
A roller pressure contact spring 14 is rotatably attached to the tip of the roller support member 12 and stretched between the roller support member 12 and the main body of the device.
By urging the roller support member 12 toward the sheet feed roller 1, the roller support member 12 is brought into pressure contact with the circumferential surface of the sheet feed roller 1.

The roller pressure spring 14 may also be a torsion coil spring that is attached around the pin 11 and presses the small-diameter pinch roller 10 at the tip against the circumferential surface of the sheet feed roller 1.

According to the structure of the above embodiment, the sheet fed from the direction of arrow B is brought into close contact with the circumferential surface of the sheet feed roller 1 by each pinch roller 2, 2, 10, and the roller 1 is rotated in the direction of arrow A. This causes the sheet to be fed.

In this case, a small-diameter pinch roller 10 that is pressed against the sheet feed roller 1 is provided immediately below (upstream side) the head surface 7 of the recording head 6, so that the sheet to be recorded comes off the pinch roller 10. It is now possible to reduce the bottom margin of the time, that is, the unprintable area (for example, 5 dragons). Conventional recording devices record approximately 1 inch (2,54 cm).
) was able to be significantly reduced.

FIG. 2 schematically shows the relationship between the upper and lower ends of the nozzle group (ink ejection openings) formed on the head surface 7 and the minimum lower end margin determined by the distance between the lower end of the nozzle group and the small diameter pinch roller 10. to show.

FIG. 3 is a longitudinal sectional view of a recording apparatus according to a second embodiment of the present invention.

In this embodiment, the guide shaft 3 on the front side of the carriage 5 is supported so as to be movable by a predetermined amount in the back and forth direction (in the direction of arrow C) with respect to the side plate (not shown) of the apparatus main body, and the rear side of the carriage 5 is supported by the side plate (not shown) of the apparatus main body. in the front-rear direction (
The carriage 5 is supported so as to be movable by a predetermined amount in the direction of arrow C), and the carriage 5 as a whole is supported so as to be movable in the front and rear directions with respect to the sheet feed roller 1 and the platen.

A small-diameter pinch roller 10 that is pressed against the sheet feed roller 1 at a position adjacent to the head front surface 7 (immediately upstream) is attached to the tip of a roller support member 12 that is swingably mounted around a fulcrum 11 provided in the main body of the apparatus. It is rotatably supported on the shaft.

In this embodiment, however, the roller support member 12 is urged toward the sheet feeding roller 1 by a roller pressure contact spring 14 and is connected to a guide shaft 3 that is movable with the carriage 5 in the front-rear direction.

That is, in this embodiment, when a sheet is fed between the small-diameter pinch roller 10 and the sheet feed roller 1, and the roller support member 12 moves backward by the thickness of the sheet against the spring 14, the sheet is moved backward by the thickness of the sheet. The carriage 5 and the recording head 6 also move in the direction that separates the sheet thickness from the platen 8, so the head gap (the gap between the head surface 7 and the printing surface of the sheet) is always constant regardless of the sheet thickness. automatically and accurately adjusted.

The second embodiment shown in FIG. 3 differs from the first embodiment shown in FIG. 1 in the points mentioned above, and the other parts have substantially the same structure.

Therefore, according to the embodiment shown in FIG. 3, in addition to being able to reduce the bottom margin as in the case of the embodiment shown in FIG. 1, the head gap can also be automatically adjusted to an appropriate amount even when the sheet thickness is different. It worked.

FIG. 4 is a longitudinal sectional view of a recording apparatus according to a third embodiment of the present invention.

In this embodiment as well, by urging the roller support member 12 supported by the fulcrum 11 toward the sheet feed roller 1 with the spring 14, the small diameter pinch roller 0 pivotally supported at the tip of the roller support member 12 is moved toward the head surface 7. It is in pressure contact at a position adjacent to.

However, in this embodiment, the roller support member 12 is integrally formed with a guide rail 18 that regulates the vertical position of the carriage 5 and guides the reciprocating movement (scanning) of the carriage 5. This guide rail 18 has a structure that allows the carriage 5 to move by a predetermined amount in the direction of arrow C (back and forth direction).

This guide rail 18 is provided in place of the guide shaft 3 in FIG.

On the other hand, the rear side of the carriage 5 is guided and supported by a guide shaft 16 installed in the main body of the apparatus so as to be movable by a predetermined amount in the front and back direction.

Therefore, the carriage 5 as a whole is urged forward (in the direction toward the sheet feed roller 1 and the platen 8) by the pressing spring 19, and the protrusion 20 formed on the front end surface of the carriage 5 hits the roller support member 12. By hitting the platen 8, it is supported at a position where a predetermined gap is formed between the platen 8 and the platen 8.

In use, when a sheet is fed into the small-diameter pinch roller 10 and the roller support member 12 moves backward (leftward in FIG. 4) by the sheet thickness against the spring 14, the carriage 5 is moved through the projection 20. It also moves backward against the spring 19.

Therefore, the position of the recording head 6 is automatically adjusted so that it is separated from the platen 8 by the sheet thickness, and the head gap is always managed at an appropriate value regardless of the sheet thickness, as in the case of FIG. 3. Can be done.

The third embodiment shown in FIG. 4 differs from the first embodiment shown in FIG. 1 in the points mentioned above, and has substantially the same structure in other parts.

Therefore, according to the third embodiment shown in FIG.
In addition to the effect that the head gap can be maintained at an appropriate value even when the sheet thickness is different, the head gap can be automatically maintained at an appropriate value.

FIG. 5 is a longitudinal sectional view of a recording apparatus according to a fourth embodiment of the present invention, and FIG. 6 is a plan view of FIG. 5.

In this embodiment, a roller 22 rotatable around a vertical axis is provided in place of the impact protrusion 20 in the embodiment shown in FIG. A rotatable roller 23 and a plate spring 24 that presses the roller 23 against the front side of the guide shaft 16 are provided.

The roller 23 is attached to the carriage 5 so as to be urged backward by the leaf spring 24. By pressing the roller 23 against the front side of the guide shaft 16 by the leaf spring 24, the entire carriage 5 is moved by its reaction. It is configured to be biased forward to bring the rollers 22 at the front portion into contact with the roller support member 12.

The fourth embodiment shown in FIGS. 5 and 6 differs in structure from the third embodiment shown in FIG. 4 in the above-mentioned points, but the other parts have substantially the same structure.

Therefore, in FIGS. 5 and 6, parts corresponding to those in FIG. 4 are indicated by the same numbers, and detailed explanation thereof will be omitted.

According to the embodiments shown in FIGS. 5 and 6, it is possible to freely set the image arrangement by reducing the minimum bottom margin of the recording sheet, and the head gap is automatically set to an appropriate amount even when the sheet thickness is different. In addition to obtaining the same effect as the embodiment shown in FIG. 4 in that the carriage 5 can be maintained accurately, the use of the rollers 22 and 23 greatly reduces the resistance when the carriage 5 moves, and has the effect of eliminating vibration noise. Obtained.

FIGS. 7 and 8 are partial perspective views illustrating a structure in which the small-diameter pinch roller 10 is pivotally supported at the tip of the roller support member 12 in each of the above embodiments.

The roller support section 12 is composed of a member extending left and right to cover the length of the sheet feed roller 1, and small diameter pinch rollers 10 are installed at three to four locations at the tip (upper end) of the roller support section 12.
is pivoted.

In the structure shown in FIG. 7, the pinch roller 10 is rotatably supported by a through shaft 26, and the protruding portions at both ends of the through shaft 26 are fitted into shaft support grooves 27 formed near the upper end of the roller support member 12. The pinch roller 10 is mounted 6 by caulking the opening of the shaft support groove 27 and fixing the through shaft 26.

In the structure shown in FIG. 8, both ends of the through shaft 26 that rotatably supports the pinch roller 10 are bent and formed into the shape shown in the figure, and the bent portions are formed in a zigzag pattern in the groove and side surface of the roller support member 12. The pinch roller 10 is rotatably supported at the tip of the roller support member 12 by stopping the hooking with elastic force.

According to each of the embodiments described above, it is possible to reduce the minimum margin at the bottom end of a sheet, and it is possible to obtain a recording device that can freely record on special sheets such as postcards and envelopes in a desired printing arrangement.

In addition, when providing the small-diameter pinch roller 10 according to the present invention, the number and arrangement of the conventional pinch rollers 2 may remain the same, but normally the number of pinch rollers 2 can be reduced as appropriate, and in some cases, it is possible to eliminate them. It is.

In addition, parts related to left and right balance such as the roller pressing springs 14 in each embodiment can be installed in a desired arrangement, such as being provided on both sides of the recording device, being provided in the center, or even providing a plurality of them in a predetermined pinch. .

〔Effect of the invention〕

As is clear from the above description, according to the recording apparatus of the present invention, a small-diameter pinch roller is rotatably attached to the tip of a roller support member attached to the apparatus main body, and the roller support member is conveyed in sheets by the roller pressure spring. By applying force toward the roller, the small-diameter pinch roller is brought into pressure contact with the portion of the sheet feed roller adjacent to the recording head, so that the minimum bottom margin of the sheet during recording can be reduced; A recording device in which the printing arrangement can be freely set can be obtained.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of a recording apparatus according to a first embodiment of the present invention, FIG. 2 is a partially enlarged side view illustrating the arrangement of the small diameter pinch roller of FIG. 1, and FIG. FIG. 4 is a vertical cross-sectional view of a recording device according to a third embodiment of the present invention, FIG. 5 is a vertical cross-sectional view of a recording device according to a fourth embodiment of the present invention, and FIG. The figure is a plan view of FIG. 5, and FIGS. 7 and 8 are partial perspective views illustrating the structure of mounting a small-diameter pinch roller, respectively. 1-----1=-sheet feed roller, 5,-,-,-,
,,-,-carriage, 6--------recording head, 7--------herad surface, 8--11----
-Platen, 10-----------Small diameter pinch roller, 12-----1--Roller support member, l
4--------Roller pressure spring. Agent Patent Attorney Yasutake Ooto

Claims (2)

[Claims] (1) A small-diameter pinch roller is rotatably attached to the tip of a roller support member attached to the apparatus main body, and a roller pressure spring biases the roller support member toward the sheet feeding roller, thereby pinching the small-diameter pinch roller. A recording apparatus characterized in that a roller is brought into pressure contact with a portion of the sheet feeding roller adjacent to a recording head. (2) The carriage on which the recording head is mounted is supported so as to be movable in the longitudinal direction, and the roller support member is kept in contact with the carriage, and the distance between the head surface and the platen is automatically adjusted according to the thickness of the sheet being fed. 2. The recording device according to claim 1, wherein the recording device is adjusted according to the following.