JPH02158555A - Recorder - Google Patents

Abstract

PURPOSE:To accurately convey recording sheet with a spur suitably set in its pressing force in accordance with the recording sheet in use for its thickness and stiffness by variably setting the pressing force of the spur pressing the recording sheet to the peripheral surface of a roller. CONSTITUTION:In a condition that a lever 23 is placed in a position III, pinch rollers 17, 18 are forced to come into press contact with a feed roller 16. Further a distance between spring hooks 22c, 23b increases to a maximum, extending a tension spring 24 to the maximum length, so that a spur 20 generates maximum force of pressing a sheet to a discharge roller 19 by tension of the spring. Here the spur 20 generates its pressing force most suitable for feeding a thick and stiff sheet, for instance, a postcard or the like. Next from this condition, in case of controlling the lever to be placed in a position II, the distance between the spring hooks 22c, 23b is shortened, decreasing extension of the tension spring 24, so that the spur 20 generates pressing force most suitable for feeding a sheet of ordinary paper or the like thinner and weaker than the postcard.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording device, and particularly to a roller that rotates with its outer peripheral surface in contact with a recording sheet, and a roller that presses the recording sheet against the outer peripheral surface of the roller. The present invention relates to a recording device equipped with a sheet conveyance mechanism having a rotatable spur.

[Prior Art] FIG. 3 shows an example of a conventional structure of a sheet conveyance mechanism section that conveys a recording sheet in an inkjet printer as a recording apparatus of this type.

In the structure shown in FIG. 3, a recording sheet (hereinafter simply referred to as a sheet) such as paper (not shown) is fed manually or by a cut sheet feeder (not shown) from behind the feed roller 1 along the paper pan 4 as shown by arrow a. and inserted between the feed roller 1 and the pinch roller 2. The sheet is pressed against the feed roller 1 by the pinch roller 2, and the feed roller 1 is rotated in direction b by the drive of the sheet feed motor, thereby being fed. The sheet is guided via a pinch roller 2.3 and a paper pan 4 onto a platen 6, and is pressed onto the platen 6 by a presser plate 5.

Then, an inkjet recording head 8 provided on a carriage 7 that travels along the platen 6 is driven, and ink droplets are ejected according to the recording data to record characters, etc. in a dot matrix pattern on the sheet. Ru. The recorded portion of the sheet is sent upward and guided between a discharge roller 9 and a spur 10. The discharge roller 9 is rotationally driven in the f direction by a sheet feed motor. Further, the spur 10 is rotatably provided, and is urged in a direction approaching the ejection roller 9 by a spring (not shown), presses the sheet against the outer peripheral surface of the ejection roller 9, and moves the sheet in the f direction of the ejection roller 9. It rotates in the e direction along with the rotation to . The sheet is further sent upward via the discharge roller 9 and the spur 10 and is discharged onto the stacker S.

As described above, the sheet conveyance mechanism of an inkjet printer uses a spur 10, that is, a gear with thin, sharp teeth, instead of a roller, to press the sheet against the discharge roller 9 for discharging the sheet. The reason for this is that the ink is not dry on the recording surface of the sheet immediately after recording, and when the surface comes into contact with the roller, the ink adheres to the roller, and the adhered ink is transferred to the sheet again, causing the sheet to become dirty. The reason for this is that the sheet is prevented from becoming dirty due to minute point contact by the thin, sharp tooth tips of the spur 10.

[Problems to be Solved by the Invention] In the structure of the sheet conveyance mechanism shown in FIG. 3, in order to accurately convey a thick, stiff sheet such as a postcard without pitch deviation, the spur 10 must move the sheet. It is necessary to increase the pressing force against the discharge roller 9. However, if the pressing force of the spur 10 is increased against a thin, stiff sheet such as plain paper, marks from the teeth of the spur may be left on the sheet or holes may be formed in the sheet.

In other words, the pressing force of the spur 10 that allows the sheet to be accurately fed without leaving marks or holes from the teeth of the spur 10 on the sheet varies depending on the thickness and stiffness of the sheet.

However, in conventional sheet conveyance mechanisms, the above-mentioned pressing force of the spur 10 is set to a predetermined value, and is set to suit plain paper, so that accurate sheet feeding is possible for thick and stiff sheets such as postcards. There was a problem that it could not be done.

Therefore, the object of the present invention is to provide a recording device equipped with the above-mentioned type of sheet conveyance mechanism, so that the sheet can be accurately fed without damaging the sheet, regardless of the thickness or stiffness of the sheet. There is a particular thing.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention includes a roller that rotates with its outer peripheral surface in contact with a recording sheet, and a recording sheet that is pressed against the outer peripheral surface of the roller. In a recording device equipped with a sheet conveyance mechanism having a rotatable spur,
The pressing force of the spur that presses the recording sheet against the outer peripheral surface of the roller is configured to be variable.

[Function] According to this configuration, by appropriately setting the pressing force of the spur according to the thickness and stiffness of the sheet conveyed by the sheet conveyance mechanism, the sheet can be accurately conveyed without damaging the sheet. Can feed sheets.

[Example] Hereinafter, details of embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 illustrate the structure of a sheet conveyance mechanism section that conveys a recording sheet (hereinafter also abbreviated as "sheet") of an inkjet printer according to the present invention. FIG. 1 is a side view of the sheet conveyance mechanism section, with some members shown in a transparent state. FIG. 2 is a perspective view of the sheet conveying mechanism, showing a state in which the platen 12, presser plate 35, etc. in FIG. 1 have been removed.

In FIG. 1, reference numeral 12 denotes a platen of a recording stand constructed in a plate shape, and is installed between a side plate 11a and a jib shown in FIG. 2 of the base 11 of the recording apparatus. Platen 1
A carriage shaft 13 is installed parallel to the platen 12 near the bottom of the front side of the printer 2, and a carriage 14 on which an inkjet recording head 15 is mounted is slidably mounted on the carriage shaft 13. There is.

The carriage 14 is driven by a carriage motor (not shown) to run parallel to the platen 12 and feed the recording head 15. The recording head 15 is driven to eject ink droplets onto a sheet (not shown) on the platen 12. Recording is done in a matrix pattern.

Near the bottom of the platen 12, a feed roller 16 for conveying sheets is rotatably supported by a shaft 16a. The feed roller 16 is rotated in the direction indicated by the arrow by a sheet feed motor (not shown) when conveying the sheet.

In order to guide the sheet along the outer periphery of the feed roller 16, a paper pan 34 is provided from behind the feed roller 16 to cover the lower side of the roller.

Pinch rollers 17 and 18 are provided below the outer peripheral surface of the feed roller 16 to press the sheet. The pinch rollers 17 and 18 are rotatably supported by a holder 27. The holder 27 approaches the feed roller 16,
It is provided so as to be movable in the vertical direction in the drawings that are separated from each other, and is biased upward by an elastic member (not shown). This bias causes the pinch rollers 17 and 18 to come into pressure contact with the feed roller 16.

A lever 23 and a cam lever 26 are provided to manually control whether the pinch rollers 17 and 18 are brought into contact with or separated from the feed roller 16. The lever 23 is provided so as to be rotatable in the directions of arrows g and h using a boss 25 protruding from the side plate 11a of the base 11 as a fulcrum. In addition, the lever 23 is locked in the respective positions indicated by symbols ■, II, % and III in FIG. The lever 23 can be rotated in the g and h directions.

On the other hand, the force lever 26 is provided so as to be movable in the λ direction in the left-right direction in FIG. The cam lever 26 is coupled to the lever 23 by fitting the convex portion 28a formed on the lower right end of the cam lever 26 in the lower right end in FIG. It is moved in the f1 direction depending on the direction.

Furthermore, a trapezoidal recess 26b is provided at the lower center of the cam lever 26.
The left end in FIG. 1 is formed as an inclined cam surface 26c. And this recess 26b
A bottle 28 protruding from the side surface of the holder 27 is engaged with the holder 27.

On the other hand, in order to discharge the sheet recorded on the platen 12, a discharge roller 19 and a spur 20 are provided facing the upper end of the platen 12 so as to be rotatable in the f direction and the e direction, respectively. There is. In this case, the discharge rollers 19 are provided on two sides, and the spurs 20 are provided on each discharge roller 1.
A total of 4 pieces are provided, 2 pieces for each piece 9.

The discharge roller 19 is a side plate 11a of the base 11.

It is rotatably supported by a shaft 30 installed between llb. The discharge roller 19 is rotated in the f direction by a sheet feed motor (not shown) when the sheet is conveyed.

On the other hand, the spur 20 is rotatably supported by a spur shaft 21 at a position facing each of the discharge rollers 19 . Spur arms 22.22 are fixed to both ends of the spur shaft 21 to support the spur shaft 21. The spur arm 22 has a long hole 22a.

22b is formed, and this elongated hole 22a.

22b, the shaft 30 of the discharge roller 19 and the side plate 11
The holder 22 is movably supported in the directions c and d along the longitudinal direction of the elongated holes 22a and 22b by fitting the shafts 31 protruding into the holes a and llb. Further, a tension spring 24 is stretched between a spring catch 22c formed below the center of the holder 22 on the right side in FIG. 2 and a spring catch 23b formed at the free end of the lever 23. 2
The holder 22 is always urged in the d direction by the tensile force of 4.

Due to the support structure and urging structure of the holder 22, the spur 20 is movably provided in directions c and d, in which it moves away from and approaches the discharge roller 19, and is urged in the direction d by the urging force of the tension spring 24. A sheet (not shown) is pressed onto the outer peripheral surface of the discharge roller 19.

With this configuration, the sheet conveyance operation is performed in the same manner as in the conventional example described above. That is, when conveying a sheet, the sheet is first conveyed along the paper pan 34 from behind the feed roller 16 as shown by arrow a to the feed roller 16. pinch roller 17
inserted in between.

Then, the sheet is fed by the rotation of the feed roller 16 in the b direction, and the sheet is guided via the pinch rollers 17 and 18, the vapor pan 34, and the presser plate 35, and is guided to the platen 12.
The recording head 15 is driven to record thereon. Furthermore, the portion of the sheet that has been recorded is transferred to the discharge roller 1.
91 is guided between the spurs 20, and sent upward through the rotational drive of the discharge roller 19 in the f direction and accompanying rotation of the spur 20 in the e direction, and is discharged onto the stacker 36.

However, according to the structure of the sheet conveyance mechanism of the printer of this embodiment, the difference from the conventional one is that not only can the pinch rollers 17 and 18 be pressed against and separated from the feed roller 16 by operating the lever 23, but also the spur In this case, the pressing force with which the sheet 20 presses the sheet against the outer peripheral surface of the discharge roller 19 can be switched to three levels. Its operation is as follows.

First, when the lever 23 is operated to the position indicated by the symbol ■ in FIG. 1, the pinch rollers 17 and 18 are in pressure contact with the feed roller 16 as shown. Or sling 22c, 23b
Since the distance between them becomes the maximum and the tension spring 24 is stretched to the longest length, the force with which the spur 20 presses the sheet against the discharge roller 19 due to the spring force becomes the maximum. The pressing force of the spur 20 at this time is assumed to be the optimum pressing force for feeding thick and stiff sheets such as postcards.

Next, from the above state, turn the lever 23 with the symbol ■! When operated to the position shown in , the spring hooks 22c, 2
3b becomes shorter and the extension of the tension spring 24 becomes smaller, so the pressing force of the spur 20 becomes smaller than in the case of the position I11. The pressing force of the spur 20 in this case is assumed to be the optimum pressing force for feeding sheets such as plain paper, which is thinner and weaker than postcards.

Note that when the lever 23 is rotated in the g direction from position III to position II, the cam lever 26 is moved in the °C direction due to the rotation, but at this point, the recess 26 of the cam lever 26 is still closed.
The horizontal surface portion b engages with the pin 28, and the pinch rollers 17, 18 are maintained in pressure contact with the feed roller 16.

When the lever 23 is further rotated from position 1 to position I, the distance between the spring hooks 22c and 23b is further shortened, and the length of extension of the tension spring 24 is further shortened. Also, tension spring 24
The angle between the direction of action of the tensile force and the d direction in which the spur 20 is movable becomes larger.

As a result, the biasing force in the d direction by the tension spring 24 is further weakened, and the pressing force of the spur 20 against the discharge roller 19 is further weakened and becomes minute.

On the other hand, as the lever 23 rotates in the g direction, the cam lever 26 moves in the direction. Then, the inclined cam surface 26c of the recess 26b presses the pin 28 downward as shown by the arrow m, so that the holder 27 is displaced in the same direction, and the pinch rollers 17 and 18 are separated from the feed roller 16.

In this way, the pressing force of the spur 20 becomes minute, and the pinch rollers 17 and 18 separate from the feed roller 16, resulting in a released state in which the sheet can be freely inserted into and taken out from the conveyance path.

As described above, according to this embodiment, the pinch rollers i'y, ta can be brought into pressure contact with or separated from the feed roller 16 by operating the lever 23, and the spur 20
In this case, the pressing force against the discharge roller 19 can be variably set in three stages. By operating the lever 23 described above to switch the pressing force of the spur 20 depending on the thickness of the sheet used, such as whether it is a postcard or plain paper, and the strength of the spine, the pressing force can be applied to the sheet. The sheet can be made into a suitable material, and the sheet will not be damaged by marks from the tips of the teeth of the spur 20 or holes will be formed on the sheet, and the sheet can be fed accurately.

In the above configuration, the pressing force of the spur 20 can be variably set in three stages, but it is of course possible to set it variably in more stages. It is also conceivable to set the pressing force of the spur 20 to be variable continuously instead of setting it variable step by step.

Further, in the above description, the pressing force of the spur 20 is set variably by manual operation of the lever 23, but it is also possible to set the pressing force of the spur 20 variably by driving a driving means such as a solenoid or a motor. In this case, the above-mentioned driving means is driven in response to manual key input from the printer's operation unit or commands from the printer's host computer, and the pressing force of the spur 20 is automatically controlled without the printer user's intervention. can be set variably.

[Effects of the Invention] As is clear from the above description, the present invention includes a roller that rotates with its outer peripheral surface in contact with the recording sheet, and a rotatable roller that presses the recording sheet against the outer peripheral surface of the roller. In a recording device equipped with a sheet conveyance mechanism having spurs,
Since the pressing force of the spur that presses the recording sheet against the outer peripheral surface of the roller is configured to be variable, the pressing force of the spur can be adjusted depending on the thickness and stiffness of the recording sheet used. can be set appropriately, and an excellent effect can be obtained in that the recording sheet is not damaged by the spurs and the recording sheet is accurately conveyed.

[Brief explanation of the drawing]

FIG. 1 shows the structure of the sheet conveyance mechanism section of an inkjet printer according to an embodiment of the present invention, and is a partially transparent side view, and FIG. 2 shows the sheet conveyance mechanism section with the platen etc. removed. FIG. 3 is a side view showing the structure of a sheet conveyance mechanism section of a conventional printer. 12...Platen 14...Carriage 15.
...Recording head 16...Feed roller 17.18.
...Pinch roller 19...Discharge roller

Claims (1)

[Claims] 1) A roller that rotates with its outer peripheral surface in contact with the recording sheet;
In a recording device equipped with a sheet conveyance mechanism having a rotatable spur that presses a recording sheet against the outer peripheral surface of the roller, the pressing force of the spur that presses the recording sheet against the outer peripheral surface of the roller is A recording device characterized in that it is configured to be set variably.