JP2993971B2 - Inkjet printer - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates generally to ink jet printers, and more particularly to ink jet printers which are mechanically simple and have better ink drying capabilities than printers without an additional drying mechanism. A thermal ink jet printer having a user facing sheet feed and return assembly which is less expensive than a printer with a mechanism. The printer disclosed below is of a type that performs printing on a substantially horizontal plane. As a result, the print media (such as paper) is removed from the substantially horizontal collection means and stored there. In addition, a service station is provided to service the printhead cartridge / carriage assembly and printhead. Unique referencing with respect to mutually critical elements ensures print quality reproducibility.

[Prior art and its problems] Conventionally, in the art of ink-jet printers, a general technique for feeding paper or other media to a print head includes a paper head and a paper technical member (platen) adjacent to the print head. It was necessary to use a specially provided pickoff or feed roller to transport the paper to the area of the printer in between. This area requires another paper drive mechanism that is used to continue transporting paper through the printhead and print zone to a paper collection tray or the like.

Therefore, the drive mechanism of the printer requires a first drive mechanism to feed the paper from the paper supply tray and a second drive mechanism to cause the paper to pass through the printhead and be stored in the paper collection tray. Become. The need to provide multiple paper drive mechanisms has increased the cost and complexity of inkjet printers.

Further, unless using specially coated paper, such prior art ink jet printers must address the problem of ink drying. If there is no mechanism to dry the ink, if the paper is output quickly, the paper will be sent to the paper output tray before the opportunity to dry the underlying paper ink is available. This means that the print on the underlying paper is rubbed and smeared. One common mechanism is to provide some type of drying means, such as a lamp or heater. However, the need for these also adds to the complexity of the printer, as it must be provided with a power supply, lamp or other heating device, and associated devices. Such devices also add weight to the ink jet printer.

Therefore, it is desirable to reduce the cost and complexity of a printer, while simplifying the components and the interaction relationships between these components. It is further desirable to provide a means for processing the printed media in a manner that does not contaminate the previously printed print media.

Ink jet printers are comprised of a plurality of interrelated elements for printing on a print medium such as paper. For example, a paper printer zone is supported by a platen, and a print cartridge secured to a bi-directional movable carriage prints characters on paper in the print zone by the printhead of the cartridge.

There are several aspects of printing that must be controlled to ensure print homogeneity between one sheet and the next, and between different thickness sheets. . For example, the distance between the printhead and the paper must be controlled, and the angle between the printhead and the paper must be controlled.

The carriage moves on the shaft substantially parallel to the print zone, but this degree of parallelism must be managed to ensure uniform printing in the transverse direction of the paper. Further, the print media passes through the print zone by drive rollers mounted on a drive shaft. This drive shaft must also be kept parallel to the print zone. Finally, the printer must be able to keep the paper flat with respect to the platen and to deal with paper wrinkles caused by the presence of wet ink. Wrinkling tends to fluctuate the gap between the paper and the printhead.

In ink jet printing technology, a printhead consisting of a plurality of nozzles of a nozzle plate is in fluid communication with a reservoir of ink. The printhead is mounted on one end of the print cartridge, and the reservoir is located inside the cartridge.

Interconnecting means are provided for sending electrical signals from the microprocessor in the printer to the printhead. In thermal ink jet printers, these signals cause a current to flow through the resistors associated with the nozzles to control the heating of the individual resistors. This heating forms ink droplets. Droplets of ink are ejected by a nozzle onto a print medium, such as paper. By heating the resistors in a particular pattern, control is added to the formation of the character pattern on the print media.

The print cartridge is supported on a carriage adapted to move bidirectionally perpendicular to the movement of the print media through the printer. The movement of the carriage is controlled by a motor and a belt drive associated therewith, the motor being controlled by a microprocessor.

The carriage often requires the use of both hands to insert the ink jet cartridge. Furthermore, the structure of the cartridge / carriage assembly often does not allow the nozzle plates to be aligned in the X, Y, and Z directions simultaneously. Finally, to ensure proper firing from the nozzles, contact between the printhead and the interconnecting means must be ensured.

Accordingly, it would be desirable to provide a cartridge / carriage assembly having the foregoing advantages without the limitations of the prior art.

The service station of an ink jet printer is intended to keep the thermal ink jet printer head in good working condition for the life of the print head. As is well known to those skilled in the art,
The printhead is formed as part of a print cartridge. The cartridge contains an ink reservoir and the printhead contains an assembly of passages, firing elements (resistors), and nozzles for firing droplets of ink onto a print medium, such as paper. .

During operation, nozzles can become clogged with ink, or bubbles can accumulate in a condition that prevents proper operation of the printhead. It is also desirable to prevent contaminants such as paper dust from affecting the operation of the nozzles and prevent the ink from drying in the nozzles when the printhead is at rest. Finally, it is desirable to wipe out any soft, viscous ink plugs that may form when the printhead is at rest. This should be done before the start of printing to ensure that all nozzles in the printhead orifice plate fire properly.

The service station can handle the aforementioned problems and requests. Although the service station is not new to thermal ink jet printers per se, the goal is to provide a service station that is easy to operate and maximizes the number of functions in a minimal space.

Some features for which a desirable service station resides include:

1. A function to clean up clogged nozzle plugs and remove air bubbles.

2. A function to cover the nozzles when not using the print head to prevent contamination.

3. A function that prevents the ink from drying in the nozzles when the print head is not used.

4. A function to wipe off contaminants attached during printing from the nozzle.

5. A function to provide a place to spray with a nozzle in order to wipe out plugs made of soft and viscous ink.

SUMMARY OF THE INVENTION According to one embodiment of the present invention, a novel inkjet printer is provided. The inkjet printer includes: (a) media supply means for supplying media to be printed; (b) media collection means for collecting printed media; and (c) media collection from the media supply means through a print zone. Means for transporting this media up to; (d) comprising a printhead, operatively associated with a carriage guide, adapted to move orthogonally to the motion of the media supported on a platen maintained in the print zone. (E) immediately before entering the print zone, deflect the media so that it is oriented in a plane parallel to the print zone so that the flatness of the media is maintained. (F) means for causing the carriage and the print medium to be referenced to the carriage guide; and (g) pre-printing when printing the next medium. (H) means for drying the ink on the printed media and transporting the printed media to the media collection means; and (h) means for controlling the operations of transporting and printing the media.

The printhead cartridge and the carriage form an assembly that includes means for securing the cartridge in place in the carriage and reference means for aligning the cartridge within the carriage. The inkjet printer of the present invention is also provided with interconnecting means for supplying electrical signals to the cartridge from control means such as a microprocessor,
The cartridge is provided with means for transmitting an electrical signal to the printhead.

Cartridges include top surface, bottom surface, side surface,
A front surface and a rear surface are provided, and the printhead is mounted on the bottom surface. The rear surface is provided with contacts for transmitting electrical signals from the interconnect means to the printhead. A reference pad is provided on the side surface. The rear surface is provided with a lip for receiving a snap spring that locks the cartridge in place in the carriage. The securing means includes a snap spring and means for receiving the reference pad of the cartridge. By means of applying force,
The interconnecting means is pressed against the contacts of the cartridge.

The printhead cartridge / carriage assembly of the present invention requires only one hand for the operator to insert and lock the cartridge in place. In addition, the cartridge / carriage assembly simultaneously aligns the nozzle plate in the X, Y, and Z directions. Finally, each time the cartridge is inserted and locked in place, the printhead and the interconnecting means are in firm contact, which ensures a proper nozzle firing in each case.

A service station is also provided for the printhead. The service station includes: (a) means for priming the printhead; (b) means for operating the service station by the carriage; and (c) means for bringing the printhead into close contact during non-printing operations. And (d) means for cleaning the print head.

By using a fixed cleaning means such as a wiper, the printhead /
The number of cleaning parts is reduced. Thread (Sl
With actuation means such as ed), no solenoid is required. Since the sled operates on its own, no external control is required except by the action of a carriage motor that controls the movement of the carriage that supports the cartridge. By using the ramp in connection with the thread,
The cap can actively seal the printhead, eliminating the need to slide the cap across the printhead orifice plate.

Reverse bow is the change in direction as the media moves away from the drive roller and slides along the platen. This change in direction is caused by positioning the platen in the print zone at an angle different from the tangent of the paper drive roller. When reverse warpage occurs in the horizontal direction of the paper (parallel to the printing direction), the paper is pressed flat against the platen by utilizing the rigidity of the paper itself. The direction of movement of the platen and print head
Since they are substantially parallel and the paper is held flat against the platen by the reverse warpage, the space between the print head and the paper is kept constant. By making the printhead at a slight angle to the plane of the print zone, paper wrinkles do not contact the printhead and the wet ink is rubbed and obscured.

In one embodiment, the output support rails support a sheet of print media during printing. At the end of printing this sheet, the platen pivots downward and the sheet falls into the output collection means under its own weight.

In an alternative embodiment, an active paper drop mechanism is provided. The mechanism comprises a pair of opposed movable rail members. Each side rail member is associated with one side of the print media, and (a) means for moving from an initial closed media support position to an interval at which media support is no longer provided; Means are provided for returning the member to the initial position.

The rail is provided with a wing member, which is pivotally fixed to the floor of the power collecting means, and whose pivot support points are spaced inward and outward from the wing member. Thus, when downward pressure is applied to the wing member, the rail rotates outward from its closed position,
It goes into a recess provided on the side of the output tray. This provides sufficient clearance for the sheet to drop onto the output stack. When the downward pressure is released,
The spring means returns the rail member to its original closed position.

In one embodiment, a platen support member associated with a platen that supports a sheet of print media during a printing operation rotates downward after printing of the sheet. The platen support member is provided with an ear-shaped member, which engages when the wing member moves downward, thereby pushing the rail member to the open position. When the rail member is closed, that is, in the extended position, the print medium is supported by the rail member. In the open position, the print media sheet falls to the output collection means by its own weight, but by then the previously printed print media sheet has been air-dried with air. By supporting the sheet from below, there is no contact between the paper handling mechanism and the top of the sheet just printed, which also eliminates ink smear.

A mechanically actuated multiplexer is provided to (1) commence sheet transport in the print zone from the paper supply tray, (2) pivot the platen downward at the end of printing on each sheet, and (3) Start the pump to prime the printhead. The multiplexer is provided with a plurality of parallel multiplexer gears, each of which is associated with one of the aforementioned functions. One actuation of such a gear is performed using a trigger mechanism. The trigger is pushed up by a follower via a suitably positioned intervening arm supported by the printhead carriage. The positioning of the intervening arm is performed by control means.

The print media and the carriage are both referenced by the same part (carriage guide). In this configuration, the print media is pressed against the underside of the carriage guide, leaves the drive rollers, passes through the reverse warpage in the print zone to the platen, where it leaves the drive rollers for printing. The carriage is referenced to the carriage guide through the slider bumps by the carriage shaft and gravity.

The carriage guide is a rigid sheet metal (for example, 0.813 mm (0.013 mm) with tight tolerances and well-controlled dimensions.
32 inches) thick). Therefore, this part
Unlike molded parts that do not provide sufficient hardness at the required thickness, they are good for reference. In the case of plastic parts, it is difficult to obtain linearity at the required thickness.

To accommodate thicker print media, the load on the spring allows the platen to move substantially perpendicular to the plane of the paper.

Further, the platen position is kept at a certain minimum distance from the carriage guide so that no paper is pinched between the carriage guide and the platen. This reduces the pulling force, minimizes skew, and reduces paper drive. The low pull force eliminates the need to reduce the print zone to provide a contact area for moving the paper. Because the paper can be pushed into the print zone.

The resulting inkjet printer is easy to manufacture, omits elements of the media drive mechanism,
The provision of a novel media drying device reduces complexity and costs.

Embodiments of the Invention Hereinafter, embodiments of the present invention will be described with reference to the drawings, and the same elements are denoted by the same reference numerals throughout. Referring to the drawings, an ink jet printer is generally indicated at 10. This new ink jet printer is characterized by certain properties that are unique to ink jet printing, and especially thermal ink jet printing.

The first unique property is shown in FIGS. 1 and 2. As you can see, the paper input or supply tray
A 12 is provided at the front of the printer 10, i.e., at the portion 14 facing the user. Feed tray 12 is manufactured to handle a significant amount of paper or other print media 16a. The paper tray 17 that slides into the feed tray 12 and slidably engages the floor is adjusted to accommodate various lengths of print media 16a and the print media is retracted to the outside. Not to go out. The front end of the paper fastener 17 is provided with a stack height gauge for limiting the height of the medium 16a. A laterally moving lever mounted below the floor member 12 and provided with means (not shown) for pressing against one side of the print media allows it to accommodate print media 16a of various widths. ing.

The front section 14 of the printer 10 has a paper output or collection tray
18 are also provided. The collection tray 18 is also structured to handle a considerable amount of media 16b, such as paper.

The ink jet printer 10 is of a type that prints on the media 16b in a substantially horizontal plane, unlike more common printers that print on a vertical plane. For printing on a horizontal surface, there are two distinctive features associated with the horizontal output collection means or collection tray 18. First, an inclined slot 20 is provided near the rear of the collection tray 18, and is inclined downward from the upper portion of the floor rail 18a of the collection tray 18. This slot 20 allows the insertion of an envelope. The sheets are simply stacked one by one on the stack of media 16a, and the last sheet stacked on the stack is the next sheet to be picked up.

Second, there is an integral, opposed output rail 22 above the collection tray 18. A pair of opposed output rails 22 are provided on top of a pair of vertical wall surfaces 21a and 21b separated by a floor member 23 on which printed media 16b are stacked during printing. In one embodiment, during a printing operation, these output rails 22 and platen 26 (shown in FIGS. 3C and 3d) support a medium 16c, such as paper, and provide ink to underlying medium 16b. Can be dried. At the end of the print cycle, when the media 16c is approaching the front 14a of the collection tray 18, the platen 26 pivots down and the media is clamped by the platen 26 and the carriage guide 27. Come off. Then, the medium 16c falls to the collection tray with its own weight. The trailing edge of the paper is the media drive roller 24 and platen 26 until the print cycle is complete.
(Shown in more detail in FIG. 9 and discussed further below).

The front portion 14 of the printer 10 is also provided with a control panel 28 that is in electrical communication with the microprocessor 29 and that performs various selections regarding the printing operation. Such control operations performed by currently available microprocessors are well known in the art and do not form a part of the present invention.

Similarly, the arrangement is such that one or more print format cartridges 30 can be inserted. The use of such print format cartridges allows the operator to select one or more print styles or fonts to customize the printed output. Such print style choices are well known and also do not form a part of the present invention.

FIG. 2 shows a microprocessor 29 with a carriage 35 moving over a carriage rod 34 and a carriage guide 27 and a flexible electrical interconnect strip 36.
Also shown is a print cartridge 32 connected to the print cartridge. The microprocessor 29 controls a carriage motor 37 for moving the carriage 35. Print cartridge
Numeral 32 is specially designed for this inkjet printer, and the thermal inkjet printer head 33
Is used. However, if the carriage interface is compatible, you can operate the printer with other inkjet printheads,
The printer can also operate with other carriage configurations. In addition, print cartridges
It is possible to reconfigure 32 to utilize other ink jet technologies, such as piezoelectric. Such reconfiguration is within the capabilities of the merchant.

FIG. 3a shows the supply tray 12 to the collection tray 18 medium 16a
The gear train 38 used to transfer the gear train is shown. The gear train 38 is controlled by the media drive motor 40 (shown in FIG. 9) via the media drive shaft 32. The medium drive roller 24 is attached to the medium drive shaft.

The gear train 38 is comprised of ten gears 44-62 arranged to transmit the rotational movement of the media drive shaft 42 from its gear 44 to a cam 64 associated with a cam gear 62. Each operation is shown in FIG. 3a.
However, gear train 38 is not shown in FIGS. 3b-3d for simplicity. The arrangement of the gears 44 to 62 is shown in FIG. The operation of the gear train
Beginning by engaging a mechanical multiplexer 63, details of its operation will be described below.

The gear train 38 has a flat part 66 as a first approximation.
Is rotated. That is, the cam 64 is shaped like a greasy kidney bean, and can carry out the function of carrying the paper to the position where the sheet 16c is picked up and returning the paper to the initial position.

To enable this operation, the supply tray 12 is comprised of two separate parts: a media support 12a and a pressure plate 12b located in approximately the same plane behind the media support. The pressure plate 12b is spring loaded by a spring 68, such as a pair of coil springs or leaf springs. When the cam 64 is in contact at its entire diameter, i.e., at the uncut portion, the pressure plate 12b of the supply tray 12 is kept in the horizontal position and in the same plane as the medium support 12a as shown in FIG. 3a.

As the cam 64 rotates to bring the flat portion 66 into contact with the upper surface of the pressure plate 12b, a spring 68 pushes up the pressure plate 12b to rotate about a fixed shaft pivot 69. As a result, the trailing edge 70 of the medium 16a can come into contact with the medium drive roller 24 as shown in FIG. 3b.

A sheet 16c is picked from the stack of media 16a and fed between the paper media drive roller 24 and a first pinch wheel 72 associated therewith. In order to be able to pick up only one sheet, it is advantageous to use a common corner separator (not shown) in the cut-sheet feeding technique. However, other sheet separation techniques are available.

The sheet of media 16c continues to rotate about the media drive rollers 24 and travels between the carriage guide 27 and a second set of pinch rollers 76 to the platen 26 where it is printed on the sheet 16c. Is performed (print zone).

By moving from the carriage guide 27 to the platen 26,
At point A (Fig. 3c, Fig. 26, Fig. 29), reverse warp (reve
rse bow) occurs. With the inverted needle at this point A, the sheet 16c is moved to the thermal ink jet print head 3.
In the area where 3 crosses (print zone B), it flattens along platen 26. This makes it possible to keep the gap between the printhead and the paper required by ink-jet technology constant and precisely controlled.

This reverse warpage is a change in the direction of the paper when the paper slides along the platen 26 away from the medium drive roller 24. This change in direction is caused by positioning the platen 26 at a different angle from the tangent of the medium drive roller 24 at the point A.

Further, the sheet 16c bends in the horizontal direction due to the reverse warpage, thereby preventing the sheet from being bent in the vertical direction. Otherwise, this sheet will fall between the pair of output rails 22.

If the gap between the thermal inkjet printhead 33 and the sheet 16c is too narrow, the printhead will smear the print, while if the gap is too wide, print quality will suffer. The gap limit depends on the particular printhead used. For many printheads, a suitable gap is about 0.762 mm to about 1.27 mm (about 0.030 mm).
Inches to 0.050 inches).

The gap between the thermal inkjet printhead 33 (FIG. 29) and the sheet 16c is kept constant over a range of print media thickness. In the case of the printer 10 of the present embodiment, the gap is desirably about 0.762 mm (about 0.030 inch) or less. If a deformable support is used for the platen 26 in order to give the platen 26 some followability,
The slight deflection allows it to accommodate thicker paper and maintain the desired narrow gap.

The shape of the cam 64 is such that the medium sheet 16c is
You can see that it has been selected to feed into the assembly. Before the pressure plate 12b begins to fall, the condition that the paper is properly picked up and sent through the first set of pinch wheels 72 must be met. The above conditions must be satisfied under all conditions, taking into account the indefinite size of the paper stack. The length of the paper is not critical, as the cam 64 makes one complete revolution each time it is actuated by the mechanical multiplexer 63.

Passive Fall of Paper: The printed sheet 16c moves on the output rail 22 until printing is completed. It can be seen that the width of the output rail 22 is sufficient to support the sheet 16c during printing, but insufficient to support the sheet if the support by the platen 26 is no longer provided. The width of the output rail 22 is about 3.175 mm with the sheet 16c for each rail.
It is selected to overlap about 9.525 mm (about 1/8 inch to about 3/8 inch).

When printing is complete, the platen is
26 turns downward. The rotation of the platen 26 is the second gear
Controlled by train 80. As with Cam 64,
Each time activated by the mechanical multiplexer 63, this gear train 80 also makes one complete revolution.

When there is no support and back-warping at the trailing edge of the sheet of paper 16c, this is enough for the sheet to drop onto the collection tray 18 with its own weight. The dropped sheet becomes the output paper sheet 16b. While printing,
The ink on the previously printed sheet 16b has been dried and the lower sheet is completely dry before the next printed sheet 16c falls under its own weight, avoiding ink smearing Is done. Therefore, a drying mechanism required for drying the ink of the sheet just printed, a component and a power supply associated therewith are not required.

Active Drop of Paper: In order to handle print media 16 such as paper during printing and stacking after the print has been completed, instead of the above, the entirety is indicated by 82 in FIGS. Figure 2 shows an active media dropping mechanism. In certain embodiments, contact with previously printed paper 16b must not occur while printing sheet of paper 16c.
The active media drop mechanism allows the ink on previously printed and stacked sheets 16b to dry.

As printing is performed on the current print medium 16c, for example, paper, the sheet is fed to the collection tray 18 to a discharge position equal to or higher than the already printed sheet 16b. The active medium drop mechanism 82 is composed of a pair of side rail members 84a and 84b spaced apart from each other and supports the current sheet 16c in the closed position to support the current sheet 16c above the output stack 16b. To hold. Each of the side rail members 84a, 84b thus engages one side of the print media along its edge.

In order to discharge the paper 16c, the side rail members 84a and 84b are moved to the open position so as not to be obstructed, for example, by turning. Then, the sheet falls on the output staff.

The side rail members 84a, 84b fit into recesses 86a, 86b provided in the vertical wall surfaces 21a, 21b. When the side rail members 84a, 84b enter the recesses 86a, 86b, the side rail members are considered to be in the open position. Return means 88a, 88b for returning the side rail members 84a, 84b to the initial closed position are provided.

Therefore, it is only necessary to act to perform the opening operation. Such an opening operation is linked to the platen 26,
This is enabled by pivoting the platen support 90 shown in FIGS. 6, 8a and 8b. The platen 26 supports the sheet 16c during the platen, particularly in the print zone indicated by B in FIG. Each end of the pivoting platen support 90 has an ear 92 at the side rails 84a, 84b, respectively.
The wings 94a, 94b are engaged to push the side rails to the open position.

When the printing of the sheet 16c is completed, the lower end of the sheet is still supported by the print 26, and the lower end of the sheet is no longer supported by the platen support 90 and the platen 26 both pivoting downward.

The tip 96 prevents the sheet 16b from being fed back below the platen 26. The tip 96 forms a part of the floor member 23 of the collection tray 18.

The return means may comprise return springs 88a, 88b assembled to each side rail member 84a, 84b to act on the side that pushes the side rail members back to the closed position.

The operation of the spring can be achieved in various ways, such as by using a coil spring or a leaf spring. In the preferred embodiment, each side rail member 84 has a depending, L-shaped peninsula or cantilevered member 98.
Is provided. This member is made as an integral part of the side rail member and curves outwardly. This results in some preloading when in the closed position. The free end 98 ′ of the cantilevered member 98 is always pressed against the stud member 100. The stud member 100 is formed as an integral part of the inner wall of the vertical wall 21.

When in the open position, the cantilevered member 98 assumes a substantially straight (deflected) shape, which exerts pressure on the stud member 100 in an attempt to return to a curved (non-deflected) shape, thereby Push each side rail member 84 back to the closed position. However, such a return is prevented as long as the ear 92 is in contact with the wing member 94. On the other hand, once such contact is released, the side rail members 84a, 84b return to their closed positions.

The side rail members 84a and 84b are fixed so that their respective ends can pivot on the floor member 23 of the collection tray 18. Side rail members 84a, 84b rotate about a pivot point spaced inwardly from wing member 94.

As shown in FIG. 6, when the platen support 90 and associated ears 92 rotate down and reach the plane of the figure, the wing members 94 engage the side rail members 84. This action causes the wing member 94 to pivot about the pivot point, thereby causing the side rail member 84 to pivot.
Is pushed into the recess 86. Thus, the side rail member 84 comes to the open position.

If the ear 92 is disengaged from the wing, this means that the platen support 90 is pivoted to its original position. In such a case, the cantilever type member is used.
The force provided by 98 returns the side rail member 84 to its original closed position.

FIGS. 8a and 8b show the mechanism of this operation. FIG. 8a shows the platen retainer 90 in its original position, the side rail member 84 in its original closed position, and the cantilevered member 98 in its intended curved state. Have been. FIG. 8b shows the platen support 90 rotated downward about the media drive shaft. Although not shown in FIGS. 8a and 8b, the ears 92 engage the wing members 94 to push the side rail members 84 outward. In FIG. 8b, it can be seen that the cantilever-type member 98 is bent to have a substantially linear shape.

Of course, if the rotating platen support (or rotating platen) is not used, other means can be used to push down the wing members 94a, 94b. In general,
The printer is provided with a means 322 (described later) for detecting the end of the sheet 16c, that is, the lower end. Various means for coupling such detection means to the wing members 94a, 94b may be used instead.

There are three main advantages provided by the active medium drop mechanism: First, side rail members
84a, 84b allows the print medium 16c to be printed on the previously printed paper 16b until the wet ink dries out.
To avoid contact. Second, the current seat 16 is lifted from below by side rail members 84a, 84b. Thus, there is nothing in contact with the side being printed, and the wet ink is driven by the active drop mechanism 82.
Avoids smearing. Third, the print media 16c falls onto the collection tray 18 regardless of the amount of stiffness due to the wrinkles there.

Medium Drive Roller: The medium drive roller is divided into segments, and is composed of a plurality of medium drive rollers 24 arranged along a medium drive shaft 42. Each media drive roller 24 performs two functions: first, it picks up paper from the input stack 16a,
It can also be transported over the paper in that figure to the B print zone, and the second print 26 enters between the segments of these drive rollers as shown in FIG. The post print can be turned.

Three medium drive rollers 24 are provided, and these rollers are provided on both sides of the medium 16 at about 12.7 mm to 19.05 mm (about 1/2 inch to about 3/4
(Inches) offset one by one to form a buckle zone and one roller in the center, so that these multiple drive rollers
Advantageously, the extension of platen 26 between 24 causes a reverse warpage at A. Also, the media drive roller 24 can be used to pick up sheets from a source of media, and a buckle zone is needed to pick up such sheets. This configuration is to be compared with the use of a media drive roller in the art that is commonly used and has a generally integral central shape.

The media drive roller 24 is advantageously made of paper made of a synthetic rubber material suitable for driving.

The media drive roller 24 is associated with a first pinch wheel 72 that grasps a sheet of media 16c picked up from the stack of paper 16a. Each of the media drive rollers 24 is also associated with a second pinch wheel 76.

The pinch wheels 72, 76 are made of compliant foam rubber. The pinch wheels 72, 76 keep the sheet 16c pressed against the media drive roller 24 as the sheet 16c moves about 180 ° around the group drive roller. A second set of intermediate pinch rollers 76 are positioned behind the other two to hold the paper on the media drive rollers in an area near an out-off-paper sensor 322 (described below). .

FIG. 9 shows a media drive train having a media drive motor 40 mechanically coupled to the media drive shaft 42 by a gear train 104.

The downward pivoting of the platen 26 (shown in FIG. 3d) is provided by an arm (not shown) of the pivoting platen support 90 which contacts the offset pin (not shown) of the pivot gear (not shown). Controlled. The pivot gear is the gear
It is coupled by a train 80 to a mechanical multiplexer 63.

Multiplexer: The multiplexer 63 used here is primed to three gear trains: a gear train 38 for picking up paper at the drive wheel, a gear train 80 for swiveling the platen 26, and a print head 33. Gear train 106 for operating pump 108
Interacts with.

The following description of the multiplexer 63 shown in FIGS. 10 and 11 is for linkage components that interact with one of the gear trains. The corresponding parts interacting with the other gear trains are identical, and such parts
To the extent that it is recognizable, the same numbers are labeled differently, but the letters are different (eg, 110a, 110b, 110
c).

The multiplexer 63 has three multiplexer gears 11
0a to 110c. Multiplexer gear 110a-11
Each of 0c has a notch 112 in the tooth 114. This portion prevents engagement with the multiplexer and pinion gear 116. The detent portion 118 allows the arm 120 of the multiplexer spring 122 to hold the multiplexer gear 110 in place. Multiplexer
The hook portion 124 of the gear 110 engages with the hook portion 126 of the trigger 128, which causes the trigger to move to the multiplexer gear 11
Zero can be rotated and the multiplexer gear meshes with the multiplexer pinion gear 116.

Each of the three triggers 128a to 128c has a hook portion which engages with the hook portion 124 of the corresponding multiplexer gear 110.
It has 126. The trigger 128 has a ledge 130 at the bottom. The upper surface 132 of the ledge 130 allows the follower 134 to push the trigger to the down position. Also, its lower surface 136, through the opening 138, allows the follower 134 to slightly lift the trigger 128, thereby rotating the multiplexer gear 110 and the notch 112 and detent 118 into place. To do. The trigger 128 also has an upper ledge 140 which is used to lift the trigger 128 by the intervening arm 142 and to initiate rotation of the multiplexer gear 110.

Multiplexer spring 122 is provided with three arms 120 for engaging corresponding detents 118 of multiplexer gears 110a-110c.

Multiplexer and pinion gear 116 has three gears
The corresponding multiplexer gear 1 including segment 144
It is designed to engage with 10. Two offset cam pins (not shown) supporting the follower 134 are tied to the same axis as the multiplexer pinion gear segment 144. Multiplexer pinion gear
116 is connected to the medium drive motor 40 via the medium drive shaft 42.

The follower 134 has two support arms 146,1 which rest on the offset cam pins of the multiplexer pinion gear 116.
Including 48. The follower 134 is also provided with a guide ledge 150 for supporting the interposed arm 142. Finally Follower 1
34 is the upper surface 13 of the ledge 130 below the trigger 128
It has two sets of ledges for engaging the 2 and bottom surface 136.

As shown in FIG. 12, FIG. 18a, and FIG.
2 is mounted on the carriage 35 and includes an end effector 152 that conveys the movement of the follower 134 to one of the triggers 128 when located under the trigger as shown in FIG.
The intervening arm 142 also includes a spring 154, and the follower 13
End Fekuta 1 if 4 is at the top of the exercise
52 can pass before the triggers 128a-128c.

In operation, the intervening arm 142 is located below one of the triggers (in this case, trigger 128a in FIG. 10 and trigger 128b in FIG. 12). Such an arrangement is made by moving the carriage 35 to an appropriate position under the control of the microprocessor 29.

Multiplexer gear 110a when trigger 128a is lifted
Rotates. As the multiplexer gear 110a rotates, it engages with the multiplexer pinion gear segment 144a.

The intervention arm 142 is removed (by laterally moving the printhead carriage 35).

The multiplexer gear 110a makes one revolution. During this time, follower 134 pulls trigger 128a back to the "down" position.
Due to the notch 112a in the multiplexer gear 110a, the multiplexer pinion gear 116 is
The driving of the gear 110a is stopped. The follower 134 in the "up" position raises the trigger 128a and places the multiplexer gear 110 in the detent position, completing the cycle.

As can be seen, all three control mechanisms can be operated mechanically, thus eliminating the need for electronic control. The only electronic involvement is the proper positioning of the carriage 35 by the microplexer 29. Of course, depending on the number of functions to be controlled, the multiplexer gear
110 may be more or less.

The relationship between the multiplexer 63 and the gear trains 38, 80, 106 shown in FIGS. 10 and 11 is shown in FIG. Reference numbers (110b and 116b) in parentheses in FIG. 3a refer to the gear train 3 of the multiplexer gear 110 and the multiplexer pinion gear 116.
This shows the relationship to 8.

Printhead Cartridge / Carriage Assembly: The printhead cartridge / carriage assembly, generally indicated at 156, is shown in FIG. Cartridge / carriage assembly 156 is carriage 3
5 and a print cartridge 32. As shown therein, the print cartridge 32 is locked in place. Electrical signals are provided from microprocessor 29 to print cartridge 32 by interconnect strip 36, as described in further detail below.

As shown in FIG. 14, the carriage 35 has a base 158 and a chute 160 attached to the base 158 by fixing means 162. The carriage 35 is conveniently made of glass-filled, carbon-filled, polytetrafluoroethylene-filled, silicon-filled polycarbonate.

Interconnect strip 36 and spring pad 164 are sandwiched by base 158 and chute 160. Spring pad 1
64 has a plurality of elastic bumps 166 as shown in FIG. 15 made of an elastic elastomer material. A spring pad 164 is provided behind a portion of the interconnect strip 36 and in a recess 168 (16th
(Fig.)

The base 158 and the chute 160 are aligned in proper relation by molded parts, such as alignment pins 170, which engage the opposing openings of the other member through corresponding openings in the interconnect strip 36.

The interconnect strip 36 comprises a strip of flexible dielectric material through which a plurality of conductive lines 172 pass, as more clearly shown in FIG. The ends of the conductive lines 172 are connection recesses 174 having a specific pattern structure.

The elastic bumps 166 of the spring pads 164 are interconnect strips
It has the same pattern structure as the 36 contact recesses 174.
As can be seen in FIG. 19, the elastic bumps 166 of the spring pads
Are means for applying a force so that the contact recess 174 can be pressed against the print cartridge 32.

The print cartridge 32 has a top surface 176, a bottom surface 178, side surfaces 180 and 182, a front surface 184, and a back surface 186. The print cartridge 32 is conveniently made of a modified polyphenylene oxide.

A thermal ink jet print head 33 is provided on the bottom surface 178 of the print cartridge. The thermal inkjet printhead 33 includes a plurality of resistors (not shown) corresponding to a plurality of nozzles (not shown) formed in a nozzle plate (not shown). Ink (not shown) is stored in a reservoir in print cartridge 32.

The print cartridge 32 also has a contact strip 190 on its back surface 186. Contact strip 190 is wrapped around bottom surface 178 to form a plurality of conductive paths or traces to the printhead resistors. Specifically, each resistor is provided with an electrical signal through its own conductive path. Contact strip 190 includes a plurality of contact pads 192 arranged in the same pattern as contact recesses 174 of interconnect strip 36. As will be described in further detail below, by locking the print cartridge to the carriage 35, the contact recess 174 matches the contact pad and the microprocessor 29 transfers the thermal ink jet printhead 33.
An electrical path is formed to each of the resistors therein. Contact strip 190 is comprised of a flexible material with a plurality of electrical passages. 3M USA (Minneapolis, MN)
Tape automation bond (TA) manufactured and sold by
B) It is desirable to use a circuit.

The upper surface 17b of the print cartridge 32 is provided with a pair of finger grips 194a and 194b. The end of the larger finger grip 194a has a V-shaped surface and may have an arrow indicating the proper orientation of the print cartridge 32. When the print cartridge 32 is locked to the carriage 35, the print cartridge
The cartridge is received on a similarly shaped surface on the carriage to provide a visual reference of orientation. Further, the lockout ear 198 has a function of preventing an error in the arrangement direction of the print cartridge 32 in the carriage 35.

As shown more clearly in FIG. 21, a reference pad 200 is provided near the base of the print cartridge 32. More specifically, two sets of reference pads 200 are provided. These are the X direction of the nozzle plate,
It has a surface sculpted for alignment in the Y and Z directions. X reference pad
200x is a surface parallel to the side surface 182. (Opposite side 1
Since a side spring 202 is provided to press the cartridge 35 against the reference pad 200x by pressing the 80, the carriage 35
Has only one X reference pad 200x. ) The Y reference pad has a formed back vertical surface 200y. The Z reference pad has an inner horizontal plane 200z which is the formed surface.
The contacts at 200y and 200z provide a pivot point 200r at which the print cartridge 32 rotates during lock-in operation.

The two reference members 204a and 204b of the support base 158 cooperatively engage one of the reference pads 200, respectively. A snap spring 206 on the top of the base 158 engages a rear ledge 208 on the back 186 of the cartridge 32.

The reference members 204a and 204b are reference surfaces against which the reference pad 200 of the print cartridge is pressed. Specifically, the reference pad 200x is pressed against the reference surface 204x on the reference member 204b (the member opposite the side spring 202).
Reference pad 200y pushes back reference surface 204y (shown in FIG. 14). The reference pad 200z presses the reference surface 204z from above.

The snap spring 206 is housed in the molded structure 210 of the base 158 of the carriage. Engagement 212 of chute 160, which will rest upon snap spring 206 when base 158 and chute 160 are assembled, has a similarly shaped V-shaped surface 196a of print cartridge 32.
A receiving inward V-shaped surface 212a is provided. A finger grip 214 is provided at the rear of the molded structure 210. A chute 160b is also provided at the front of the chute 160.

The carriage rod 34 is mounted on the base 158 of the carriage 35.
A bearing 216 is provided which is associated with the bearing. The carriage rod 34 is substantially parallel to the media drive shaft 42 along which the carriage 35 can be moved in both directions. The carriage 35 is moved by a belt (not shown) attached to the carriage by a belt fixture 218. The belt is attached to a carriage motor 37 under the control of the microprocessor 29.

The reference means, ie, the slider bump 220, rests on the surface of the carriage guide 27. Due to the weight of the carriage 35, the slider bumps 220 are preloaded towards the carriage guide, so that a constant contact is obtained. The slider bump 220 is made of a low-friction, durable material, which can be a separate part or a molded part of the cartridge 35. The slider bump 220 serves to keep the print head 33 at a fixed distance from the print medium.

The carriage base 158 is also provided with an intervening arm 142 fixed to the hollow tube 222. The function of the intervening arm 142 relates to mechanically triggering the multiplexer 63 as described above.

The printhead lock-in mechanism is in the X direction,
The printhead lock-in / lock to align the nozzle plate in the Y and Z directions simultaneously, align the contact pads on the electrical interconnect strip 36, wipe it, and apply a load to it.
The mechanism is considered unique. This feature is achieved without adding a bale, latch, or lever arm, as found in other ink jet printers. The user places the print cartridge 32 around the pivot point 200r with arrow 224 (FIG. 18a).
Rotation in this direction results in alignment of the nozzle plate and application of a load to the interconnect strip 36. Print cartridge finger grip 19
This is done by pinching and pulling the finger grip 4a and carriage finger 214 with the thumb and forefinger.

Only after the user can easily drop the print cartridge 32 onto the carriage chute 160 can the print cartridge 32 be pulled and set to the locked position. A side spring that aligns the print cartridge 32 until the print cartridge 32 begins to rotate and is in the locked-in position (shown in FIG. 18b)
202, snap spring 206 exerts no force on the print cartridge. This leaves room for an unobstructed path that allows the user to easily drop the print cartridge 32 to the pre-rotation position shown in FIG. 18a. However, when the print cartridge 32 is inserted, a slight force is applied by the side spring 202.

Print cartridge 32 has a pivot point of 200r
Rotate around. User print cartridge
During rotation of the 32, an alignment function is performed before the electrical interconnect strip 36 is loaded.
First, one side 180 of the print cartridge 32 engages the side spring 202. The side spring 202 provides a reference in the X direction to the print cartridge 32 by pushing the print cartridge 32 laterally while the X reference pad 200x contacts the X reference member 204x of the print cartridge 32. The result is accurate, slop-free (no-sl
op) Alignment of the Nords plate in the X direction is performed.

The next operation is alignment in the Z direction. The shelf-like projection member 20 at the rear of the print cartridge 32
8 When striking the rear metal snap spring 206, this spring pushes the cartridge in the Z direction until the Z reference pad 200z contacts the Z reference member 204z on the carriage 35. This results in accurate, slop-free Z-direction positioning of both the electrical interconnect strip 36 and the nozzle plate.

Print cartridge 32 has a pivot point of 200r
As it continues to rotate about the print cartridge, the wiping action is performed by the contact recesses 174 of the interconnect strip 36 against the electrical interconnect contact pads 192 of the print cartridge contact strip 190. As a result, contacts 174 and contact pads 192 may be applied before interconnect strip 36 is loaded.
Oxides and contaminants will be wiped from the surface.

Following the wiping operation, the print cartridge electrical contact pads 192 are aligned in the X direction. This is done by the heel lock tabs 226a, 226b on the outside rear of the print cartridge.
Is the heel lock slot 228a, 228b of the carriage 35
It is time to engage. The contact strip 36 on the carriage 35 provides a precise reference to the heel lock slot 228 for the alignment pin 170, which allows the alignment required by the contact strip 36 to the contact recess 174 of the cartridge. I can take it. Contact strip 190 is secured to print cartridge 32 and is referenced from the assembly machine.

Finally, the print cartridge 32 is precisely aligned in the Y direction. The spring pads 164 of the electrical interconnects of the carriage 35 need to flex a suitable distance in the Y direction to maintain the required contact force. On the back 186 of the print cartridge 32, a spring pad 164
Pushes back the contact recess 174 and the contact pad 192, which are electrical contacts, and the Y reference pad 200y of the print cartridge 32 contacts the Y reference member 204y of the carriage 35. This results in the contact strips located on the contact strip 190 on the back 186 of the print cartridge 32.
The required force on the pad 192 is maintained. This provides for accurate positioning of the nozzle plate in the Y direction, as well as control of the nozzle's rotational alignment.

At the front of the print cartridge 32, the necessary contact force is maintained by a rear snap spring 206. When the print cartridge 32 rotates to the lock-in position, the ledge member 20 at the rear of the print cartridge 32
8 bends the snap spring 206 at the rear, and passes through the point 206a over the center of the snap spring 206. Snap spring 206
Is designed to apply about 70% of its force in the Y direction. This is the force required to maintain electrical contact to the interconnect strip 36 located on the back 186 of the print cartridge 32.

The print cartridge 32 has a rear snap spring 206
The print cartridge emits an audible "pinch" when passing through the center crossing point 206a to inform the user that the print cartridge is in the proper lock-in position. The spring pads 164 provide the proper force to hold the print cartridge in its precisely aligned position with the significant acceleration and shock loads experienced by the print cartridge during normal printing operations.

To remove the print cartridge 32 from the carriage 35, all that is required is to pinch the finger grip 194b of the cartridge and the finger grip 160b of the carriage with the thumb and forefinger to pull them in and rotate the print cartridge. Until the print cartridge crosses the center point and enters the unlocked position,
The rear shelf 208 of the cartridge 32 deflects the rear snap spring 206. A "ping" sound informs the user that the print cartridge 32 can now be lifted and removed from the carriage 35 for disposal.

Service Station: FIG. 22 shows the assembled service station 23
0 is shown. The service station 230 is shown generally at 108 and includes a peristaltic pump, sled 234, and wiper bracket 236. The service station 230 is shown in a position that covers the printhead 33 of the print cartridge 32.

The service station 230 provides an area at one end of the bi-directional movement of the carriage 35. Carriage 35 holds print cartridge 32 in a locked, aligned state. The carriage 35 moves bidirectionally along a carriage rod 34 by a belt (not shown) normally connected to a carriage motor 37. In the configuration shown in FIG. 22, the print medium 16c is located on the left side of the service station 230 in a position perpendicular to the plane of the drawing.

The peristaltic pump 108 includes a tube 238, a roller 240, and a pump body 244. As best shown in FIG. 23a, the principle of a conventional peristaltic pump is that the roller 24
It operates by squeezing the pipe 238 between 0 and the pump body 244. Conveniently, the pump body 244 is molded into the chassis of the printer 10. In the present embodiment, the chassis forms a frame of the printer.

The roller 240 has an axial hub 246 mounted on a track 248 of the pump body 244.

The restriction point of peristaltic pump 108 moves along a portion of the length of tube 238. A pressure difference is created during this operation to allow the priming operation to be performed on the printhead.

It should be noted that peristaltic pump 108 utilizes only one roller 240 instead of three rollers as in the prior art. Since the tube 238 is only squeezed by 210 degrees of movement of the roller 240, this peristaltic pump does not require any extra components, such as a solenoid-operated vent valve, to be coupled into the system as is commonly done in the prior art. Allows for ventilation. With this configuration, when the cap is covered, the print head can ventilate with the outside air (to be described in more detail later), thereby preventing a pressure increase when the cap is crushed (FIG. 24b, 24c), even the slightest pressure increase when capping is unacceptable, as it will get into the bubble print head 33.

By using one roller 240, the tube 238 can be relaxed during rolling. Thus, during operation of the peristaltic pump 108, the tube 238 will not be pulled into the peristaltic pump 108 and the tube will not be subjected to a compression set.

As can be seen in FIG. 23a, one end of tube 238 is attached to the bottom of cap chamber 250. The other end of the tube 238 is in free space located above an absorbent pad (not shown). The absorbent pad is used as a holding container while the ink evaporates into the air.

Ventilation to the outside air is only about 0.762mm to about 1.524mm inside diameter
This is done by utilizing a long tube (about 0.030 inches to about 0.060 inches). The small inner diameter allows for very slow diffusion, creating an effective vapor seal while allowing venting of the cap chamber 250 into the atmosphere. This unique aspect of the structure would be difficult to achieve in other ways.

The rollers 240 of the peristaltic pump 108 employ a peripheral ridge 252 to help center the tube 238 in the area of greatest pinching force. Therefore, this structure is more tolerant of manufacturing variations.

The roller 240 is mounted on the roller carrier 242, and when the multiplexer 63 is activated, the bevel gear 254 which engages the bevel gear 256 of the pump body makes one rotation when the multiplexer 63 is activated, so that the roller 240 reaches a predetermined position.

The roller carrier 242 of the peristaltic pump 108 is designed to be assembled by a robot (or other automated machine). As assembled straight from top to bottom, the robot places roller 240 and then snaps roller carrier 242 in place. There are no fasteners to hold this part and a molded snap 25
8 engages with the boss 260 formed on the chassis, thereby fixing it at all predetermined positions.

Turning now to FIGS. 24a-24c. As the thermal inkjet printhead 33 moves toward the capable position (shown in FIG. 24c), the pen support 262 of the print cartridge 35 collides with the arm 264 of the sled 234 and the sled aligns with the cap 266. And this places a cap around the pen orifice in the orifice plate. The orifice plate is part of the printhead 33 but is of small size and cannot be easily seen on the scale of the drawing depicted here.

As the pen support 262 collides with the arm 264, the sled 234 rises up the ramp 268 and pushes the cap 266 up around the orifice plate of the printhead 33 to seal the orifice from the atmosphere. Lamp 268 may conveniently be molded into the wall of the printer chassis. Boss 270 supports thread 234 on ramp 268.

As the sled 234 raises the ramp 268, the pen catcher 272 engages the slot 274 of the printhead 33. Thereafter, when the print cartridge 32 leaves the service station, the pen catcher 272 ensures that the sled 234 is returned to the inactive position shown in FIG. 24b.

The purpose of tilting the sled is to prevent friction of the cap 266 and to maintain the cap 26 over the life of the printer.
6 is to make it unnecessary to replace. Also,
This tilting movement causes the print cartridge 32 to move into position, thereby activating the peristaltic pump 108 via the multiplexer 63 and backing out of the multiplexer, but with the printhead capped throughout the entire period. You can try to keep it. Thus, the sled configuration of this embodiment has a strong impact on product reliability (by reducing cap wear) and on multiplexer design (by allowing cap-over operation). Is to give.

Once engaged with the multiplexer 63, the carriage
The movement of 35 is coupled to the roller carrier 242 via bevel gear 254 and bevel gear 256 by gear train 106 (shown in FIG. 9).

Before being capped, printhead 33 traverses wiper 276 secured to wiper bracket 236.
The wiper 276 is provided with a blade, the edge of which wipes paper dust and other contaminants from the orifice plate of the printhead 33. Wiper 27
6 is conveniently made of an elastic material such as nitrile rubber, but is cleaned by the edge of a pocket (not shown) at the bottom of the wiper 276 printhead 33. These pocket edges are formed on both sides of the printhead 33 by the metal tab / tape assembly described above.

A control algorithm has been developed for the service station of the present invention. At the time of initial power-up, a plurality of times from all nozzles into the cap chamber 250, for example, three times
Two injections are performed. Each time the print cartridge 32 leaves the service station 230, multiple passes from all nozzles to the spitoon 278 shown in FIG. 25a, which is part of the subassembly of the wiper bracket 236,
For example, four injections are performed. Each time the cap 266 engages, multiple, eg, four, shots are fired from all nozzles into the cap chamber 250. Further, during printing, all the nozzles of the print head 33 are drained 278
A plurality of injections are performed periodically, for example, every 60 seconds, for example, four times.

Such injection has two purposes. First, to clear out any plugging that may have occurred in the nozzles before the start of printing. This function is common to all inkjet printers. Second, it provides the moisture generated by the droplets ejected into the cap chamber 250 to keep the printhead 33 from drying out during capping. This feature is unlikely to be used in other inkjet printers, and it is clear that the humidity of the printhead 33 itself is inactive and can supply moisture to the capped nozzles. It is an advantage.

To eliminate the strong ink plugging material and the print head such bubble viscosity problem, the flow rate of the ink in the nozzle is optimally from about 1 to about 5 cm ³ / min. To interpreted these problems printhead, ink discharge amount of about 0.06～0.15Cm ³ is optimal.

Referencing System: FIG. 26, similar to FIG. 9, shows some of the related components that are involved in the referencing of the various components in the printer. The gear trains 38, 80, 16 have been omitted and a cartridge / carriage assembly 156 has been added.

As is apparent from FIG. 27, the carriage 35 includes a slider bump 220 mounted on the surface of the carriage guide 27. Slider / bump depending on the weight of carriage 35
Preload the carriage guide 27 to 220,
A defined contact is thus obtained. Slider bump 220
May be made of a low-friction, durable material and may be a separate part or may be a part molded as part of the carriage 35. The slider bump 220 is a disposable print cartridge 32
It is also possible to use a molded part as a part of the device. Slider bump 220 serves to keep printhead 33 at a fixed distance from print medium 16c. For a balance between optimal printing and minimizing smear caused by wrinkles, this fixed distance should be between about 0.762mm to about 1.27mm (about 0.030 inches to about 0.050mm).
Inches).

The platen 26 is referenced to the bottom of the front edge of the carriage guide 27 by platen bumps 280. The platen bumps 280 are provided on both sides of the paper and outside the width of the widest paper accommodated in the printer so that they do not interfere with the paper (see FIG. 29). The platen spring 282 preloads the platen bump 280 to the carriage guide side (FIG. 28). The platen bumps 280 provide a fixed spacing between the platen 26 and the carriage guide 27. The spring loads the platen 26 from the platen support 90, the drive shaft
42. It serves to eliminate sensitivity to tolerances up to the carriage guide 27 via a chassis (not shown).

The application of a spring load (by platen spring 282) to platen 26 allows platen 26 to adapt to thick print media such as envelopes. The height of the platen vap 280 is set so that thin media, such as paper, can slide through the gap created by the bumps (this eliminates resistance to paper) and the height, such as envelopes The media is required to depress platen 26 against spring 282.

The height of the platen bump 280 is such that the gap between the platen 26 and the carriage guide 27 is about 0.1524 mm to about 0.381 mm.
(About 0.006 inches to about 0.015 inches). As the platen 26 is pushed down by the thicker media, the excess thickness is adjusted on the side opposite the print side, and the print surface is kept at a relatively constant distance from the print head 33. The thick media pushes down the platen 26, which increases drag. However, as the media becomes thicker, the compression of the pinch wheels 72 and 76 also increases, thereby increasing the driving force more than enough to compensate for the increase in drag.

The platen angle is maintained using reference bumps 284 relative to platen support 90 associated with platen 26. The reference bump 284 is sufficiently spaced from the front edge of the carriage guide 27 so that the angle between the printhead and the paper (the angle θ _{1 in} FIG. 29) is about 1 ° to about 6 ° as described below. Be placed.

The platen support 90 is pivotable about the axis of the media drive shaft 42 and controls the downward pivoting of the platen 26 for paper handling operations as described above. The downward rotation is performed when the platen support 90 contacts an offset pin (not shown) of a pivot gear (not shown). The pivot gear is coupled to a mechanical multiplexer 63 by a gear train 80 for pivoting the platen 26 downward.

The print cartridge 32 is mounted on the carriage 35 as described above.
As a reference, it is ensured that each time the cartridge is locked in exactly the same position on the carriage.

The carriage 35 is mounted on a carriage rod 34 and referenced to the carriage guide 27 by its slider bumps 220 as described above.

To maintain sufficiently consistent spacing and angles, the front edges of carriage rod 34 and carriage guide 27 must be parallel. These two parts must also maintain the proper orientation.

To do this, one side (here the left side) of each of the components (carriage rod 34 and carriage guide 27) is referenced to the component molded into the printer chassis and the right side of the right wall. The printer chassis and the right side wall used here constitute a printer frame.

By keeping the ends of each part referenced to the same part, the carriage rod 34 and carriage guide
The tight mounting between the 27 allows for parallelism and orientation.

FIG. 28 shows one arrangement in which the sheet 16c is fed by the media drive roller 24 below the carriage guide 27 and travels around the media drive shaft 42 to reach the platen 26. I have. Carriage guide
The transition from 27 to platen 26 causes sheet 16c to reverse warp at point A (immediately after print zone B). By the carriage guide 27, the sheet 16c is bent not in a straight line (see FIG. 29) drawn from the medium drive roller 24 to the platen 26 but in an arc shape. This change in direction
This is caused by positioning the medium drive roller 24, the platen 26, and the carriage guide 27 so that the angle of the sheet 16c when the sheet 16c leaves the medium drive roller 24 is different from the angle of the platen 26. Carriage guide 27
Of the seat 16c is thereby positioned so as to cause the sheet 16c to bow. This angle change is
The angle θ ₂ in FIG. 29 is preferably between about 5 ° and about 45 °.

FIG. 29 shows the angle from the print head to the paper. As you can see, sheet 16c is printhead 3
3 moves at an angle θ ₁ . For optimal results, sheet 16c is at a positive angle of about 1 ° to about 6 °.
This positive angle is sufficient to prevent wet ink smearing by a portion of printhead 33 due to paper wrinkles. Paper wrinkles are caused by the swelling of the paper due to the absorption of wet ink, which results in the sheet 16c
Rises and moves toward print head 33. By angling the sheet 16c downward from the printhead 33, clearance is provided to address the effects of wrinkles.

Angle of sheet 16c with respect to print head 33 (θ ₁ )
Is obtained by tilting the paper downward and the printhead upward. The angle of sheet 16c is controlled by maintaining the angle of platen 26 as described above.
The angle of the print head 33 is controlled by the height of the slider bump 220. As can be seen from FIG. 28, when the height of the slider bump 220 is further increased, the carriage 35 rotates clockwise to increase the angle of the print head.

(A) Reverse warpage is caused, the print medium 16c and the carriage 35 are referenced to the same component (carriage guide), and a spring load is applied to the platen 26 and the reference bump 280 to fix the carriage from the carriage guide. Minimizing the spacing allows the printhead-to-paper spacing from one sheet of print media to the next to be substantially consistent, regardless of media thickness or component tolerances.

These techniques allow the user to print on top of a page or drive paper with low force without touching the print surface or reducing the print zone to provide such a contact area. , And can also handle paper.

Other Features: The paper out-of-range sensor 322 detects when the lower end of the printed paper 16c passes through a certain point. At that point, a signal is sent to the microprocessor 29 to indicate that the paper has gone out of range.

The out-of-range sensor 322 shown in FIGS. 30 and 31 is provided with a flag 324, one end 324a of which slides into engagement with a slot or groove 326 in the carriage guide 27. The other end 324b of the flag 324 is the printer 10
Cooperating with the sensing means 328 of the printed circuit board 330 having the electronic device for controlling Flag 324 is pivotally mounted on pivot 332 at end 324a and has a depending portion 324c adapted to engage and disengage groove 326.

The sensing means 328 comprises an optoelectronic light source 328a and a detector spaced a distance corresponding to the thickness of the end 324b of the flag 324.
It is desirable to have 328b. An opening 334 is provided in the raised portion of the end 324b of the flag 324.

As shown in FIG. 32b, while the sheet 16c is being printed, the flag 3 is turned on by the light source 328a by the sheet paper 16c.
The 24 apertures are typically kept out of the light path in the light source / detector assembly 328. Therefore during this time the light source
The light path between 328a and detector 328b will be interrupted. However, the trailing edge of seat 16c is at trip point 336.
Of the flag 324, it fits into the groove 326 of the end 324a. At the same time, the other dark part 324b of the flag 324 enters the optical path of the sensing means 328, thereby, as shown in FIG.
Through the opening 334, a light beam can be passed from the light source 328a to the detector 328b. The software algorithm prints closer to the bottom edge of the paper, so that a further fixed number of lines, for example, six lines, can be printed.

The pinch associated with the pinch wheel allows 338 to print to the possible final position on sheet 16c. The pinch spring 338 is bifurcated and forms two spring portions 340a, 340b on either side of the pinch roller 76. By placing the spring portions 340a, 340b at this location on the pinch roller 76, media drive roller 24 wear can occur at a different location than the pinch roller. Spring portions 340a on both sides of the contact area of the pinch roller,
The placement of 340b allows the sheet 16c to be driven on an unworn surface and provides improved line feed throughout the life of the printer 10. FIGS. 33 and 34 show one of the pinch spring / roller assemblies. FIG. 33 shows the assembly from the front, and FIG. 34 shows the assembly from the top.

〔The invention's effect〕

The novel single-cut inkjet printer 10 of the present invention is useful for various printing applications.

Accordingly, an ink jet printer is provided which is simplified at a low cost and combines the operation of moving the paper into one mechanism so that the printed medium can be sufficiently dried. As will be apparent to those skilled in the art,
Some changes and modifications of obvious nature may be made without departing from the spirit of the invention, and such changes and modifications must be considered to be within the scope of the invention as set forth in the appended claims. .

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a view showing an operating state of the embodiment in FIG. 1 with a cover removed, and FIGS. 3a to 3d are views in FIG. FIGS. 4 and 5 show the handling of the hair in the embodiment, FIGS. 4 and 5 show the collecting tray in the embodiment in FIG. 1, FIGS. 6, 7, 8a and 8b.
FIG. 9 is a view showing a side rail member in the embodiment in FIG. 1, FIG. 9 is a view showing a gear train in the embodiment in FIG. 1, and FIGS. 10 and 11 are views in FIG. FIG. 12 is a view showing a multiplexer according to the embodiment; FIG. 12 is a view showing a structure for operating the multiplexer gear of the embodiment in FIG. 1;
FIGS. 13, 18a and 18b show the carriage / cartridge assembly in the embodiment of FIG. 1;
FIG. 16, FIG. 17, FIG. 17, and FIG. 20 are views showing the carriage of the embodiment in FIG. 1, FIG. 15 is a view showing the spring pad of the embodiment in FIG. 1, and FIG. 1 is an enlarged sectional view showing an electrical connection of a carriage in the embodiment in FIG. 1; FIG. 21 is a view showing a print cartridge in the embodiment in FIG. 1;
FIG. 22 is a view showing a service station in the embodiment shown in FIG. 1, FIGS. 23a to 23c are views showing a peristaltic pump in FIG. 22, and FIGS. 24a to 24c are views in FIG. Diagram showing threads in the service station, No. 25
25a and 25b show the wiper bracket in FIG. 22, FIG. 25c is a sectional view taken along line AA of FIG. 25a, FIG. 26 and FIG.
FIGS. 28 and 29 are views for explaining the provision of a positional reference between components in the embodiment of FIG. 1, and FIGS. 28 and 29 are diagrams of a medium near the thermal ink jet print head in the embodiment of FIG. FIG. 30, FIG. 31, FIG. 32a, and FIG. 32b show the out-of-range sensor in the embodiment shown in FIG. 1, and FIG. 33 and FIG. FIG. 4 is a diagram showing a pinch wheel and a pinch spring in the embodiment shown in FIG. 10: Inkjet printer 12: Supply tray 16a, 16b, 16c: Media 18: Collection tray, 20: Inclined slot 22: Output rail, 23: Floor member 24: Media drive roller, 26: Platen 27: Carriage guide, 28 : Control panel 29: Microprocessor 30: Print format cartridge 32: Print cartridge 33: Thermal inkjet print head 34: Carriage rod, 35: Carriage 36: Interconnect strip 37: Carriage motor 38: Gear Train, 40: Media drive motor 42: Media drive shaft, 62: Cam gear 63: Multiplexer, 64: Cam 68: Spring, 72, 76: Pinch wheel 80: Gear train 82: Active media drop mechanism 84a, 84b: side rail member 86a, 86b: recess 88a, 88b: return means 90: platen indicator, 92: ear 94a, 94b: wing, 96: protrusion 98: cantilever member 100: stud member 102: pivot point 104, 106: gear train 108: peristaltic pump 110a to 110c: multiplexer gear 112: notch 116: multiplexer pinion gear 118: detent member, 120: arm 122: multiplexer spring 124: hook Part, 126: hook part 128: trigger, 130: shelf protrusion 134: follower, 138: open part 140: shelf protrusion, 142: intervention arm 144, 146: pointing arm 150: guide shelf protrusion 152: end effector , 154: spring 156: cartridge / carriage assembly 158: base, 160: chute 160b, 214: finger grip 162: fixing means, 164: spring pad 166: elastic bump, 168: recess 170: alignment pin 172: Conductive line, 174: Contact recess 190: Contact strip 192: Contact pad 194a, 194b: Finger grip 196a, 212a: V-shaped surface 198: Lockout ear 200: Reference pad, 202: Side spring 204 a, 204b: Reference member 206: Snap spring, 208: Shelf-like projection member 212: Engagement part, 216: Bearing 218: Belt attachment 220: Slider bump 222, 236: Tube 226a, 226b: Heel lock tab 228a , 228b: Heel lock slot 230: Service station 234: Thread 236: Wiper bracket 240: Roller, 242: Roller carrier 244: Pump body, 246: Hub 248: Truck 250: Cap chamber 252: Outer ridge 254, 256: Bevel gear 258: Snap, 260, 270: Boss 262: Pen support, 264: Arm 266: Cap, 268: Lamp 272: Pen catcher 274: Slot, 276: Wiper 278: Drain, 280: platen bump 282: platen spring, 284: reference bump 322: paper out-of-range sensor, 324: flag 328: sensing means, 330: printed circuit board 334: opening, 336: trip point 338: pinch spring, 340: Spring part

────────────────────────────────────────────────── ─── Continuing on the front page (72) John D. Rose, Vancouver Northeast 25th Street, Vancouver, Washington, U.S.A. 18312 (72) Inventor David W. Pinkell, Pullman Northwest Wayne Street, Washington, U.S.A. 1740 Number 6 (72) Inventor Jay Paul Harmon Vancouver Northeast Twenty-Eight Kand Street, Washington, USA 9012 (72) Inventor Kevin El Moon Vancouver, Washington, USA Southeast Evergreen Highway 10512 (72) Inventor William Earl Hashby United States of America Southeast McGillibley, Vancouver, Northton 14313 (56) References JP-A-62-239073 (JP, A) JP-A-60-204342 (JP, A) US Pat. Field (Int.Cl. ⁶ , DB name) B41J 2/01

Claims (10)

(57) [Claims] 1. An ink jet printer for printing on a print medium, comprising: (a) a medium supply means for supplying a print medium to be printed; (b) a medium collection means for collecting printed print medium; A) a medium transport means for transporting the medium from the medium supply means through the print zone to the media collection means; d) a cartridge mounted on a carriage and moving along a carriage guide; The carriage is held on a platen maintained in the print area; (f) to maintain substantially flat print media;
Means for orienting a print medium in a plane parallel to the print area prior to the print area; (g) means for drying ink on the medium printed immediately before the medium during printing of the medium; (H) an assembly for locking the printhead and the carriage for use with the cartridge having the following (i) to (vi): (hi) the carriage; (h-ii) the carriage receives the cartridge. (H-iii) the base supporting means includes a reference providing means, and the cartridge is engaged with the reference providing means to be arranged at an appropriate printing position; (h-iv) the base (Hv) control signal, wherein the support means includes a holding means, and locks the cartridge at a predetermined position of the carriage means. (H-vi) said cartridge includes a reference system facing and cooperating with said reference providing means of said base support means, said reference system comprising: Is positioned properly with respect to the cartridge while it is engaged and positioned with the carriage, and holds the position of the cartridge during a printing operation. (I) The reference applying means comprises a pair of lower Stretching in the direction
A reference member having reference surfaces in at least two directions, spaced apart and opposed to each other, cooperating with the reference system of the cartridge; and (j) the cartridge including a rear shelf, wherein the cartridge includes a rear shelf. The holding means includes first spring means and cooperates with the rear shelf to hold a cartridge in a locked position; (k) the carriage includes dropping means, the dropping means comprising: An ink jet printer attached to a support means to assist in guiding the cartridge to a predetermined position. 2. The invention as defined in claim 1 wherein said drop means includes a second spring means for applying a relatively light force to the cartridge to assist in positioning and positioning the drop means inside.
Printer according to paragraph. 3. The cartridge of claim 2, wherein said electrical interconnect means includes an interconnect strip disposed intermediate said base support means and said cartridge, terminating in a plurality of recesses arranged in a predetermined arrangement to provide electrical contact to said cartridge. The printer according to claim 2, which is obtained. 4. The cartridge includes a contact strip having a plurality of electrically conductive pads arranged in a predetermined arrangement with the interconnect strip to obtain an electrical connection; the cartridge includes a plurality of resistors; 4. The printer of claim 3, wherein a contact strip is terminated at said conductive pad to provide a plurality of conductive paths to said resistor. 5. The printer according to claim 1, wherein said printer includes spring pad means disposed intermediate said base support means and said interconnect strip to bias said interconnect strip against a cartridge to obtain electrical interconnection. Item 5. The printer according to Item 4. 6. The spring pad means includes a plurality of outwardly projecting bumps, the bumps being arranged in a manner similar to the arrangement of the recesses and the conductive pads, and providing a good electrical connection between the interconnect strip and the cartridge. The printer of claim 5, wherein the bump biases the recess against the conductive pad. 7. The cartridge includes a top, a bottom, and the printhead, the printhead is mounted on the bottom, the reference system of the cartridge includes two sets of similar reference pads, and the reference application. A pad disposed near the bottom and in a substantially symmetrical position with respect to the printhead, wherein one of the fiducial pads engages one of the pair of fiducial members; The printer according to claim 1, wherein the other one engages with the other one of the pair of reference members. 8. The transport means includes an active media dropping mechanism having a pair of opposed and spaced side rail members associated with the media collection means, each side rail member including a respective one of the print media. Engaging one side; (i) moving the side rail member from an initial media support position to an open position, wherein the means does not support the media; and (ii) moving the side rail member to the initial position. The printer according to claim 1, further comprising: returning means. 9. The printer includes a service station for maintaining the cartridge, wherein the printhead provided on the cartridge has nozzles for ejecting ink, and the service station comprises: (i) the printhead. (Ii) the wiping means is fixed to one end of the stroke of the carriage, and (iii) connected to the wiping means and surrounding the nozzles of the print head, thereby forming the print head. (Iv) the sled means is actuated by the carriage when the carriage moves to a predetermined position at the one end of the stroke, (v) connected to the sled means, Pump means for sucking ink from the print head. Item 10. The printer according to Item 8. 10. The printer according to claim 9, wherein: (i) first means for applying the print medium to the platen; and (ii) the print head attached to the cartridge, and A second means for applying a reference to the carriage guide, (iii) a third means which is closely attached to the platen, and applies the platen to the carriage guide, and (iv) the first means comprises a printing device. A means for creating a reverse warpage in the media and directing the print media from above the platen in a plane substantially parallel to the direction of printing.