JP3680550B2 - Consumables and image forming apparatus with detachable attachments - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a consumable that is mounted on an image forming apparatus and an image forming apparatus that drives a consumable carriage through the consumable.
[0002]
[Prior art]
In recent years, relatively easy serial printers such as inkjet printers and thermal transfer printers have become the mainstream and widely used as personal image forming apparatuses. In these printers, a consumable liquid ink cartridge or ink ribbon cartridge is mounted on a carriage in a replaceable manner.
[0003]
Such a printer usually includes a screw roll (also referred to as a lead screw or a screw shaft) having a spiral groove formed along a peripheral surface thereof, and the carriage engages with the spiral groove of the screw roll. A print head including a pin or a screw nut and an ink jet head integrated with a carriage or a heat transfer heat generating head is provided.
[0004]
The screw roll is driven to rotate by a drive mechanism, thereby driving the pin of the carriage through the spiral groove, thereby causing the print head to reciprocate in the main scanning direction (width direction of the recording paper). During this time, the print head forms images and characters on the recording paper. In general, the print head of a printer is often configured to perform a printing operation during both forward and backward movements of the carriage in order to increase the printing processing speed.
[0005]
[Problems to be solved by the invention]
By the way, the above-mentioned spiral groove and the pin engaged therewith are mutually worn on the contact surface. One spiral groove has a small degree of wear because the contact with the pin (pantograph) is instantaneous, just like the power feeder overhead line of the train, but the other pin is worn out because almost the same part is always in contact with the spiral groove. Relatively intense.
[0006]
FIG. 5A is a diagram showing the relationship between the pin and the spiral groove so worn, and FIGS. 5B and 5C are diagrams showing a printing defect caused by the wear of the pin. As shown in FIG. 5A, when the pin 1 is worn, play of the gap A occurs in the moving direction of the pin 1 with respect to the spiral groove 2 by the worn amount.
[0007]
Therefore, if the print head is configured to print both the forward and backward movements of the carriage indicated by the arrow 4 with respect to the paper 3 as shown in FIG. Then, the print head is displaced by the amount of play of the gap A due to the wear. For example, when a vertical ruled line is drawn, as shown in FIG. A “deviation a” corresponding to the gap A occurs between the vertical ruled line printed in the backward direction.
[0008]
This “deviation a” state is the same even in the case of character printing or image printing (printing). Thus, with the conventional printer, the printing accuracy deteriorates over time, and printing (printing) occurs. It has the problem of significantly reducing the image quality. This has been a big problem especially when high-definition printing accuracy is required as in today.
[0009]
For this reason, in order to avoid the above-described deterioration in image quality, printers that print on the print head only during the carriage forward movement have been put into practical use. However, this has only caused a new problem that the printing speed is halved and user dissatisfaction increases.
[0010]
An object of the present invention is to provide an image forming apparatus that minimizes wear of pins engaged with a carriage in view of the above-described conventional situation.
[0011]
[Means for Solving the Problems]
First, a consumable according to a first aspect of the present invention is the above-described image forming apparatus having a screw roll having a spiral groove formed on a surface thereof, a driving unit that rotationally drives the screw roll, and a carriage on which the consumable is placed. A consumable that is placed on a carriage and includes an engagement pin that engages with a spiral groove of the screw roll when placed on the carriage.
[0012]
Next, an image forming apparatus according to a second aspect of the present invention includes a screw roll having a spiral groove formed on a surface thereof, a driving unit that rotationally drives the screw roll, and a carriage on which a consumable item is placed. A consumable item having an engagement pin that engages with a spiral groove is mounted on the carriage, and the rotational force of the screw roll by the driving means is transmitted to the engagement pin of the consumable item through the spiral groove. The carriage is configured to move through the engagement pin and the consumable.
[0013]
Subsequently, a consumable item according to a third aspect of the present invention is an image forming apparatus including a screw roll having a spiral groove formed on a surface thereof, a driving unit that rotationally drives the screw roll, and a carriage on which the consumable item is placed. A consumable to be placed on the carriage, an engagement pin that engages with a spiral groove of the screw roll when placed on the carriage, and a holding means for movably holding the carriage on the screw roll; , And is configured.
[0014]
According to a third aspect of the present invention, there is provided an image forming apparatus comprising: a screw roll having a spiral groove formed on a surface thereof; a driving unit that rotationally drives the screw roll; and a carriage on which a consumable is placed; A consumable comprising an engaging pin that engages with a groove and a holding means that holds the carriage movably on the screw roll is mounted on the carriage, and the carriage is held on the screw roll by the holding means, The rotational force of the screw roll by the driving means is transmitted to the engaging pin of the consumable through the spiral groove, and the carriage is moved through the consumable by the driving force transmitted to the engaging pin. Configured to let
[0015]
The consumable is, for example, a liquid ink cartridge as described in claim 5, and is a thermal transfer ink ribbon cartridge, for example, as described in claim 6. Further, the screw roll is configured to have a hardness higher than that of the engaging pin of the consumable, for example, as in claim 7.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view schematically showing a configuration of a main part (printing mechanism) of the image forming apparatus according to the first embodiment. As shown in the figure, a screw roll that is rotationally driven in both forward and reverse directions by a motor 12 as indicated by a double-headed arrow Z in the figure, inside the housing 11 of the image forming apparatus 10 (in the diagonally upper right direction in the figure). 13 is passed in the width direction of the apparatus main body, and a carriage 14 is slidably engaged with the screw roll 13 in the apparatus width direction as indicated by a double arrow X in the figure. A flexible cable 15 for transmitting and receiving print signals is connected between the carriage 14 and a control device (not shown) of the apparatus main body.
[0017]
A cartridge 16 is detachably mounted on the carriage 14. The cartridge 16 is a liquid ink cartridge if the image forming apparatus is an ink jet printer, and if the ink jet head is not integrated with the carriage 14, the ink jet head is also mounted on the carriage 14 together with the liquid ink cartridge. Is done.
[0018]
If the image forming apparatus is a thermal transfer printer, the cartridge 16 is a thermal ink ribbon cartridge. Similarly, in this case, if the heating head is not integrated with the carriage 14, the cartridge 16 generates heat. The head is also mounted on the carriage 14 together with the thermal ink ribbon cartridge.
[0019]
In the image forming apparatus 10, when the recording paper 17 is inserted from a paper feeding port at the front of the apparatus via a paper feeding device (not shown), the paper feeding roller 18 and the paper feeding roller 19 that is in pressure contact with the recording paper 17 are recorded. And is intermittently conveyed at a constant distance to the rear of the inside of the apparatus indicated by the arrow Y in the figure.
[0020]
When the intermittently transported recording paper 17 is in a stopped state, printing is performed on the platen 21. During this printing, the rotation of the motor 12 causes the screw roll 13 to rotate in the forward direction, and the details of the cartridge 16 that fits into the screw groove 13-1 formed on the peripheral surface of the screw roll 13 will be described later. The guide pin moves along one direction of the direction indicated by the double arrow X in the drawing, for example, the right direction along the apparatus width direction by the screw groove 13-1 that alternately rotates to the left and right.
[0021]
As a result, the carriage 14 is reciprocated in the right direction via the cartridge 16, and printing (printing) is performed by a print head (not shown) on the carriage 14 based on a print signal transmitted from the control device via the flexible cable 15. ) Is performed. That is, an image is formed in the main scanning direction (paper width direction) of the recording paper 17.
[0022]
When the forward movement of the carriage 14 is completed, the recording paper 17 is again conveyed by a fixed distance in the Y direction and stopped, and on the contrary to the above, the image is formed in the main scanning direction. By repeating this operation, an image is formed on the sheet surface of the designated range of the recording paper 17. When the image formation is completed in this way, the recording paper 17 is sandwiched between the paper discharge roller 22 and the paper discharge roller 23 and discharged outside the apparatus.
[0023]
FIG. 2 is an enlarged perspective view showing the configuration of the carriage 14 portion. In the figure, the cartridge 16 is shown removed from the carriage 14 to show the configuration of the carriage 14, and the cartridge 16 is shown to show the engagement relationship between the cartridge 16, the carriage 14 and the screw roll 13. 16 is partially cut away. Also, the same components as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG.
[0024]
As shown in the figure, the carriage 14 has a vertical section and a plane section in the shape of a bowl, and is externally fitted to the screw roll 13 by a bearing 24 formed in a bowl-shaped corner. Is slidably engaged with the screw roll 13. A plurality of signal line contacts 25 are disposed in the vertical portion of the carriage 14 erected above the bearing 24, and the signal wiring of the flexible cable 15 is connected to the embedded portion of the contact 25. .
[0025]
When the cartridge 16 is mounted on the carriage 14, the exposed portion of the contact 25 contacts and contacts the contact of the drive unit of the print head of the cartridge 16. Further, an engagement hole 26 with the cartridge 16 is formed below the contact 25 in the vertical portion of the carriage 14, and the screw groove 13-1 of the screw roll 13 is positioned beyond the engagement hole 26. doing. Locking claws 27 a and 27 b are disposed on both sides of the vertical portion of the carriage 14 above the engagement hole 26.
[0026]
The locking claws 27a and 27b are arranged so that, when the cartridge 16 is pushed into the vertical portion of the carriage 14 and attached as shown by an arrow B in the figure, The cartridge 16 is locked to the carriage 14.
[0027]
At this time, the drive guide pin 28 protruding from the mounting side of the cartridge 16 is inserted into the screw groove 13-1 of the screw roll 13 through the engagement hole 26. As a result, when the motor 12 (see FIG. 1) rotates in both forward and reverse directions and the screw roll 13 rotates in both directions as indicated by a double-headed arrow Z in FIG. 1, this rotation passes through the screw groove 13-1. Is transmitted to the drive guide pin 28 and converted into a reciprocating motion in the width direction of the apparatus body indicated by a double arrow X. As a result, the carriage 14 is reciprocated in the apparatus width direction through the cartridge 16 as described above.
[0028]
Here, the drive guide pin 28 is formed using a material having a lower hardness than the screw roll 28. Therefore, the wear that occurs when the drive guide pin 28 slides and slides in the screw groove 13-1 is mostly generated on the drive guide pin 28 side.
[0029]
By the way, the recording material such as liquid ink incorporated in the cartridge 16 is a consumable item that decreases with use, and the cartridge 16 is replaced by this consumption. At the time of this replacement, the drive guide pin 28 becomes new at the same time, so that the fitting accuracy between the screw roll 13 and the drive guide pin 28 is maintained almost in the same manner as in the initial state.
[0030]
As described above, the drive guide pin 28 is automatically replaced with a new one corresponding to an appropriate frequency of use, so that wear of the drive guide pin for driving the carriage can be periodically eliminated. High-definition that can minimize deterioration of the printing accuracy in the main scanning direction due to wear of the drive guide pin, and thus can maintain stable carriage driving indefinitely and is hardly affected by changes with time. Printing can be performed.
[0031]
FIG. 3 is a perspective view schematically showing a configuration of a main part (printing mechanism) of the image forming apparatus according to the second embodiment. In the figure, in order to show the configuration of the carriage 14 ′, the cartridge 16 ′ is shown removed from above the carriage 14 ′, and the engagement relationship between the cartridge 16 ′ and the screw roll 13 is shown. For the sake of illustration, the cartridge 16 'is shown partially cut away. The configuration shown in the figure is the same as the configuration shown in FIG. 1 except for the cartridge 16 'and the carriage 14'. A description of the operation is omitted.
[0032]
In the carriage 14 ′ shown in the figure, an engagement hole 24 ′ formed at a joint portion between a vertical portion and a horizontal portion is fitted on the screw roll 13 very gently. A plurality of contacts 25 'similar to the contacts 25 in FIG. 1 are exposed on the upper end surface of the vertical portion of the carriage 14'. The lower embedded portion of the contact 25 ′ is connected to the flexible cable 15.
[0033]
Further, locking claws 27 'are provided upright on both sides of the horizontal portion of the carriage 14'. When the cartridge 16 ′ is pushed and mounted toward the horizontal portion of the carriage 14 ′ as shown by the arrow C in the figure, the engaging portion of the cartridge 16 ′ (because it is in the shade on the lower surface in the figure) The cartridge 16 'is locked to the carriage 14'.
[0034]
At this time, on the one hand, the contact 25 ′ is in contact with and connected to the contact of the drive portion of the print head of the cartridge 16 ′, and on the other hand, the drive guide pin 29 and the bearing 31 of the cartridge 16 ′ are engaged with the screw roll 13. .
[0035]
FIGS. 4A and 4B are side views showing a state where the drive guide pin 29 and the bearing 31 of the cartridge 16 ′ are engaged with the screw roll 13. As shown in FIG. 2A, the bearing 31 is divided into an upper fixed bearing 31a and a lower movable bearing 31b. The lower movable bearing 31b is rotatable with the support shaft 33 as a fulcrum. Is attached.
[0036]
A slot 32 is formed in the rotating arm 31c extending from the support shaft 33 to the opposite side of the lower movable bearing 31b. The head portion of the drive guide pin 29 is fitted in the groove 32, and is engaged with the lower movable bearing 31b via the rotating arm 31c. On the other hand, the drive guide pin 29 is supported and engaged with the upper fixed bearing 31a so as to be slidable in the vertical direction.
[0037]
A flange 29-1 is formed at the top of the upper portion of the drive guide pin 29 fitted into the slot 32, and a washer 34 is fixed at a position approximately 1/3 lower than the flange 29-1. Yes. A push spring 35 is interposed between the washer 34 and the rotating arm 31c. Due to the urging force of the push spring 35, the rotating arm 31c is always pressed against the flange 29-1 of the driving guide pin 29, so that the driving guide pin 29 and the rotating arm 31c are always slidably engaged without being loosened. doing.
[0038]
From the bearing released state shown in FIG. 4 (a) (the state in which the cartridge 16 'is removed above the carriage 14' as shown in FIG. 1), the cartridge 16 'is moved into the carriage 14' as shown by the arrow C in FIG. When it is pushed toward the horizontal portion so as to be mounted, the tip of the drive guide pin 29 is fitted into the screw groove 13-1 of the screw roll 13 and comes into contact with the groove bottom.
[0039]
Further, the cartridge 16 'is pushed down until the upper fixed bearing 31a comes into contact with the upper half surface of the circumferential surface of the screw roll 13, so that the drive guide pin 29 is moved relative to the upper fixed bearing 31a as shown in FIG. As a result, the washer 34 and the push spring 35 push up the rotating arm 31c, and the rotating arm 31c is supported on the support shaft 33 as a fulcrum, as shown by the arrow D in the figure. As a result, the lower movable bearing 31b is rotated and closed to the right (counterclockwise direction) as shown by an arrow E in the figure, and is screwed together with the upper fixed bearing 31a. Engage with 13 without slack.
[0040]
Thereafter, when the screw roll 13 rotates in both forward and reverse directions, the drive guide pin 29 moves forward and backward in the direction perpendicular to the paper surface of FIG. Thereby, the carriage 14 'shown in FIG. 3 repeats reciprocating movement in the width direction of the apparatus main body via the cartridge 16'.
[0041]
【The invention's effect】
As described above in detail, according to the present invention, the drive guide pin that engages with the screw roll for driving the carriage is made of a material having a lower hardness than the screw roll, and is a consumable part that is periodically replaced. Therefore, the wear of the drive guide pin with respect to the screw roll can be periodically eliminated and recovered, thereby minimizing the error of the carriage movement in the main scanning direction caused by the wear of the drive guide pin. Therefore, stable carriage driving can be continued indefinitely, and high-definition printing can be performed with almost no change with time.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a configuration of a main part (printing mechanism) of an image forming apparatus according to a first embodiment.
FIG. 2 is an enlarged perspective view illustrating a configuration of a carriage portion of the image forming apparatus according to the first embodiment.
FIG. 3 is a perspective view schematically illustrating a configuration of a main part (printing mechanism) of an image forming apparatus according to a second embodiment.
FIGS. 4A and 4B are side views showing a state in which a drive guide pin and a bearing of a cartridge according to a second embodiment are engaged with a screw roll.
5A is a diagram showing a relationship between a conventional worn pin and a spiral groove, and FIG. 5B and FIG. 5C are diagrams showing a printing defect caused by pin wear.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pin 2 Spiral groove 3 Paper 4 Arrow A Space | gap a by wear A Printing deviation 10 Image forming apparatus 11 Housing 12 Motor 13 Screw roll 13-1 Screw groove 14, 14 'Carriage 15 Flexible cable 16, 16' Cartridge 17 Recording paper 18 Paper feed roller 19 Paper feed roller 21 Platen 22 Paper discharge roller 23 Paper discharge roller 24 Bearing 24 'Engagement hole 25, 25' Contact 26 Engagement hole 27a, 27b, 27 'Locking claw 28, 29 Drive guide pin 29 -1 Flange 31 Bearing 31a Upper fixed bearing 31b Lower movable bearing 31c Rotating arm 32 Groove hole 33 Support shaft 34 Washer 35 Push spring

Claims (7)

A consumable article placed on the carriage of the image forming apparatus, comprising: a screw roll having a spiral groove formed on a surface thereof; a driving unit that rotationally drives the screw roll; and a carriage on which the consumable article is placed. ,
A consumable comprising an engagement pin that engages with a spiral groove of the screw roll when placed on the carriage. A screw roll having a spiral groove formed on its surface, a driving means for rotationally driving the screw roll, a carriage for placing consumables,
Have
A consumable item having an engagement pin that engages with the spiral groove is mounted on the carriage, and the rotational force of the screw roll by the driving means is transmitted to the engagement pin of the consumable item through the spiral groove. ,
An image forming apparatus, wherein the carriage is moved through the engaging pin and the consumable. A consumable article placed on the carriage of the image forming apparatus, comprising: a screw roll having a spiral groove formed on a surface thereof; a driving unit that rotationally drives the screw roll; and a carriage on which the consumable article is placed. ,
An engagement pin that engages with a spiral groove of the screw roll when placed on the carriage;
Holding means for movably holding the carriage on the screw roll;
Consumables characterized by comprising A screw roll having a spiral groove formed on its surface, a driving means for rotationally driving the screw roll, a carriage for placing consumables,
Have
A consumable comprising an engagement pin that engages with the spiral groove and a holding means that movably holds the carriage on the screw roll is mounted on the carriage,
Holding the carriage on the screw roll by the holding means;
The rotational force of the screw roll by the driving means is transmitted to the engagement pin of the consumable through the spiral groove,
An image forming apparatus, wherein the carriage is moved through the consumable by a driving force transmitted to the engagement pin. The consumable item according to claim 1, wherein the consumable item is a liquid ink cartridge. The consumable item according to claim 1 or 3, wherein the consumable item is a thermal transfer ink ribbon cartridge. 5. The image forming apparatus according to claim 2, wherein the screw roll is configured to have a hardness higher than that of the engaging pin of the consumable.

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