JPH01125238A - Cartridge-carriage assembly - Google Patents

Abstract

PURPOSE:To enable easy assembly and disassembly and enable a carriage to be accurately mounted on a carriage with favorable reproducibility, by providing the carriage, a means for fixing a printing cartridge at a predetermined position in the carriage, and an interconnecting means for supplying an electrical signal to the cartridge. CONSTITUTION:A cartridge 14 is turned around a turning point 56r, when a positioning function is executed before an electric interconnecting strip 16 is loaded. First, when one side face 36 of the cartridge 14 is engaged with a side face spring 58 provided by molding at a side face of a carriage, the cartridge is pushed sideways until an X reference pad 56x makes contact with a reference surface 60x, whereby a reference in X-direction is provided for the cartridge 14, and positioning in the X-direction is performed. Next, when a self-shaped member 64 provided at a rear part of the cartridge 14 meets a metallic snap spring 62 on the rear side, the spring pushes the cartridge in Z-direction. As a result, both the strip 16 and a nozzle plate are positioned with respect to the Z-direction, and finally, the cartridge 14 is accurately positioned with respect of Y-direction.

Description

TECHNICAL FIELD OF THE INVENTION This invention relates to inkjet printers, and more particularly to printhead-carriage alignment and lock-in mechanisms for electrical connections that control the printhead.

BACKGROUND OF THE INVENTION In inkjet printing technology, a printhead has a plurality of nozzles on a nozzle plate that are hydrodynamically associated with an ink reservoir.

The printhead is attached to one end of the print carriage, and the ink reservoir is located inside the carriage.

Interconnect means are provided for communicating electrical signals from a microprocessor within the printer to the printhead.

In the case of thermal inkjet printers, these signals supply current to resistors associated with the nozzles to control the heating of particular resistors, thereby forming ink droplets.

A droplet of ink is ejected through a nozzle and onto a print medium, such as paper. By heating the resistor according to a specific pattern, the pattern, such as characters, formed on the print media is controlled.

The print cartridge is supported by a carriage that is configured to move bidirectionally at right angles to the movement of print media through the printer. The movement of the cartridge is controlled by a motor controlled by a microprocessor.
Controlled by a motor and associated belt drive.

Inserting an inkjet cartridge into a carriage often requires the use of two hands or two movements. Additionally, many cartridge/carriage configurations do not allow simultaneous alignment of the nozzle plate in the xlY and Z directions. Finally, the contact between the printhead and the interconnection means must be reliable to ensure proper firing from the nozzles.

OBJECTS OF THE INVENTION It is an object of the invention to provide a cartridge/carriage assembly with the aforementioned advantages without the limitations of the prior art.

SUMMARY OF THE INVENTION According to one embodiment of the present invention, a printhead cartridge/carriage assembly includes (a) a carriage; (b) means for securing the print cartridge in position within the carriage; (c) ) interconnection means for providing an electrical signal to the cartridge, the interconnection means comprising force-loading means for urging the interconnection means against the cartridge;

The cartridge has a top, bottom, sides, front, and back. It has a printhead on the underside, contacts to connect to the printhead on the backside, a reference pad on the sides, and a lip on the back side that receives a snap spring that locks the cartridge in place within the carriage. The securing means includes a snap spring and means for receiving a datum pad on the cartridge. The force-loading hand forces the interconnection means against the contacts of the cartridge.

This cartridge/carriage assembly requires the operator to use only one hand to insert and lock the cartridge in place. Additionally, the cartridge/carriage assembly allows simultaneous alignment of the nozzle plate in the x, y, and z directions. Finally, contact between the printhead and the interconnection means is ensured each time the IJ is inserted and locked into position, thereby ensuring that the nozzles fire correctly each time.

EXAMPLES Referring now to the drawings, like reference numbers refer to like elements throughout. A print showing the whole number in 10.
A cartridge/carriage assembly is shown in FIG. Cartridge/carriage assembly 10
is equipped with a carriage 12, on which a cartridge 1 is attached.
4 is shown locked in place. Interconnection strip 16 provides electrical signals from a microprocessor (not shown) to cartridge 14, as described more fully below.

As shown in FIG.
8 and a chute 20 attached thereto by means of tightening means 22. Carriage 12
is preferably glass-containing, carbon-containing, polytetrafluoroethylene-containing, or silicone-containing polycarbonate.

Interconnections) The IJ knob 16 and spring pad 24 are provided with a plurality of resilient protrusions 26, as can be seen from the diagram. The spring pad 24 is located in a recess 25 (shown in FIG. 4) in the base support 18 of the carriage after a portion of the interconnect strip 16, as will be described more fully below.
It can be stored inside.

The base support 18 and the chute 20 have pips 2
They are aligned in the correct relationship by molded shapes such as 7. Each small protrusion 27 engages an opposing hole in another member through a corresponding hole in the interconnect strip 16.

Interconnection strip 16 is comprised of a strip of flexible dielectric material and carries a number of conductive tracks 28, as can be seen more clearly in FIG. The conductive line 28 terminates in a convex contact protrusion or dimple 30 formed in a specific pattern.

The protrusions 26 on the spring pads 24 are configured in the same pattern as the dimples 30 which are the contact pattern of the interconnect strips 16. As can be seen in FIG. 7, the protrusion 26 of the spring pad is in contact with the dimple 3.
0, and presses the dimple 30 against the cartridge 14.

The cartridge 14 has a top surface 32, a bottom surface 34, and side surfaces 36.3.
8, a front surface 40, and a rear surface 42. Cartridge 14 is preferably made from modified polyphenylene oxide.

A printhead 44 is provided on the bottom surface 34.

resistor (not shown). Ink (not shown) is stored in an ink reservoir inside cartridge 14.

The cartridge 14 also has a rear surface 4 as shown in FIG.
2 is also provided with a contact strip 46.

Contacts) The IJ tube 46 is wrapped to the bottom surface 34, providing multiple conductive paths or traces to the resistor. In particular, each resistor is supplied with an electrical signal along a unique conductive path.

Contact strip 46 includes a plurality of concave contacts.
A pad 48 is provided, which is connected to the interconnect strip 1.
They are arranged in the same pattern as the convex contact dimples 30 of No. 6. As will be explained in more detail below, when cartridge 14 is locked into carriage 12, dimples 30 mate with recessed contact pads 48 to form an electrical path from the microprocessor to each resistor in printhead 44. .

Contact strip 46 is constructed from a flexible material with a plurality of electrical traces thereon.

Preferably, a tape automatic bond (TAB) circuit of the type manufactured and sold by 3M Corporation (Minneapolis, Minn., USA) is employed.

For example, as shown in FIG. 1, the top surface 32 of cartridge 14 includes a pair of finger grips 50a150b.
is provided. Larger finger grip 50
A V-shaped member 52a is provided at the end of a. An arrow may be provided here to orient the cartridge 14 in the correct direction. Cartridge 14 to carriage 12
When locked into place, the cartridge is received into the same shaped surface of the carriage that provides a visual reference for correct orientation. Lockout ears 54 further serve to prevent cartridge 14 from becoming misoriented within carriage 12.

A reference pad 56, more clearly seen in FIG. 9, is located near the base of the car IJ jig 14.

More specifically, two sets of reference pads 56 are provided. These constitute a sculpted surface that aligns the nozzle plate in the x, ySz directions. X reference pad 56x is a surface parallel to side surface 38. (There is only one X reference pad 56x because the carriage 12 is provided with a side spring 58 that pushes against the opposite side 36 and forces the cartridge 14 onto one side of the chute 20.) The Y reference pad has a shaped surface. It is composed of an upper vertical surface 56y. The Z reference pad consists of an internal horizontal surface 56z that is a shaped surface. A pivot or rotation point 56r is provided at the junction of 56y and 56z about which the cartridge 14 rotates during the lock-in operation.

L-shaped member 60a attached downward to base support 18
, 60b each cooperatively and matingly engages one of the reference pads 56. A snap spring 62 on the top of the chute 20 engages a shelf 64 on the rear surface 42 of the cartridge 14.

The L-shaped members 60a and 60b push the reference surface 60x of the cartridge 14 (a member on the opposite side of the reference bar). Reference pad 56y
returns toward the reference plane 60y (shown in FIG. 2).

The reference pad 56z is pushed downward toward the reference surface 60z.

The snap spring 62 is housed in a molded feature 66 in the base support 18 of the carriage.

A mating housing 67, located above the snap spring 62 when the base support 18 and chute 20 are assembled, has an inward V-shaped surface 66a that receives the same-shaped surface 52a of the cartridge 14. .

A finger grip 68 is provided behind the housing 66. A finger grip 20b is also provided on the front surface of the shoe 20 of the cartridge.

The base support 18 of the carriage 12 includes a bearing 70 associated with a carriage rod (not shown). The carriage rod is positioned substantially parallel to a paper drive axis (not shown) along which carriage 12 can be moved in both directions. Carriage 12 is moved by a belt (not shown) attached to the carriage by belt attachment 72. The belt is attached to a carriage drive motor (not shown), which is controlled by a microprocessor.

The reference means, i.e. the slider protrusion 74,
It is placed on the surface of the guide 76. The weight of the carriage 12 causes the slider protrusion 74 to preload the carriage guide, thereby providing a constant degree of contact.

The slider protrusion 74 is made of a low-friction, low-wear material, and can be a separate component or a molded part of the carriage 12. Slider protrusion 74 serves to maintain printhead 44 at a fixed, constant distance from the print media.

The base support 18 of the carriage also includes an interposer arm 7 fixed to an axis 80.
It is equipped with 8. The inserter arm functions as a cartridge/
It pertains to mechanically triggering the feature of a service station where carriage assembly 10 is parked between printing operations and is not relevant to the present invention.

This lock-in mechanism of the print head allows the nozzle plate to
, ySz direction as well as aligning, wiping, and loading the contact pads of the electrical interconnect strip 16. This is accomplished without separate bails, latches, or lever arms as found in other inkjet printers. Nozzle plate alignment and interconnection strip 160 loading occurs as the user rotates cartridge 14 about rotation point 56r in the direction of arrow 82 (FIG. 6a).

The user holds the cartridge's fin grip 50a and the carriage's finger hold.
Do this by holding 68 between your thumb and forefinger.

Aligning side springs 58 and snap springs 62 push cartridge 1 into its lock-in position.
No force is applied to the cartridge until 4 begins to rotate into the lock-in position (shown in Figure 6b). This provides a clear path for the user to easily drop the cartridge 14 into the pre-rotation position shown in Figure 6a. However, the side-kicker spring (side-kicker spr.
ing) 20 exerts a light force when inserting the cartridge 14.

Cartridge 14 rotates about reference pad 56, specifically about rotation point 56r. As the user rotates cartridge 14, electrical interconnect strip 16
The alignment function is performed before the is loaded. Initially, one side 36 of the cartridge 14 engages a side spring 58 molded into the side of the carriage. The side spring 58 provides an X reference to the cartridge 14 by pushing the cartridge sideways until the X reference pad 56X contacts the X reference pad or reference surface 60x on the cartridge 14. As a result, accurate and error-free (no 5top) alignment of the nozzle plate in the X direction is achieved.

The next operation that occurs is alignment in the Z direction. A shelf-like member 64 at the rear of the cartridge 14 connects to the rear metal snap spring 6.
2, the spring pushes the cartridge in the Z direction until the Z reference pad 56z contacts the reference surface 60z, which is the Z reference pad of the carriage 12. The result is precise, error-free positioning of both the electrical interconnect 16 and the nozzle plate in the Z direction.

As the cartridge 14 continues to rotate into position about the rotation point 56r, the concave contact pads 48 for electrical interconnections of the contact strips 46 on the cartridge meet the dimples that are the convex contacts of the interconnect strips 16 on the carriage. 30 to be lightly wiped away. This provides improved reliability over conventional printer dimpled interconnects because oxides and contaminants are wiped from dimples 30 and recessed contact pads 48 before interconnect strip 16 is loaded.

Following the wiping operation, the recessed contact pads 48 for electrical connections on the cartridge are aligned in the X direction.

This occurs when the outer rear heel lock tab 84a% 84C of the cartridge 14 engages the side 86a186c of the heel lock slot 86 of the carriage 12. The interconnect strip 16 of the carriage 12 is accurately referenced to the lock slot 86 by the pin 27, thereby aligning the interconnect strip 16 with the cartridge 1.
Perform the necessary alignment with the concave contact pad 48 of No. 4. Contact strip 46 is affixed to cartridge 14 with something such as glue or adhesive;
Standardized by assembly machines.

Finally, the cartridge 14 is accurately aligned in the Y direction. The rubber spring pads 24 of the electrical interconnections of the carriage 12 must be displaced an appropriate distance in the Y direction to maintain a predetermined contact force.

On the rear surface 42 of the cartridge 14, the rubber spring 24 pushes back the electrically contacting dimples 30 and recessed contact pads so that the cartridge Y reference pad 56y contacts the cartridge Y reference surface 60y. This places the necessary force on the contact pads disposed on the contact strips 46 on the rear surface 42 of the cartridge 14.

In addition to being able to accurately position the nozzle plate in the Y direction,
The rotational alignment of the nozzle can be adjusted.

On the top surface 32 of the cartridge 14, the necessary forces in the Y and Z directions are maintained by rear snap springs 62.

As the cartridge 14 rotates into the lock-in position, the rear lip or ledge 64 of the cartridge 14 displaces the rear snap spring 62 to the over-center point of the snap spring.
62a (Figure 6a). Snap spring 62 is designed to apply approximately 70% of its force in the Y direction. This is interconnect strip 1 for electrical interconnection
6 to the rear surface 42 of the cartridge 14.

When the cartridge 14 passes the over-center point 62a of the rear snap spring 62, the cartridge produces an audible "snapping" sound, indicating to the user that the cartridge 14 is in the correct lock-in position. The force of the interconnection spring pad 24 is +Jj 14
Suitable for holding the car in its correct alignment under the large accelerations and shock loads experienced by the car under normal printing conditions.

To remove cartridge 14 from carriage 12, the user simply presses cartridge finger grip 50b.
All you have to do is grip the finger grip 20b of the carriage with your thumb and forefinger and turn it while applying pressure. The rear shelf member 64 of the cartridge 14 displaces the rear snap spring 62 until the cartridge is in an off-center position.

The carriage 12 is now disposed of the cartridge 14.
A "snapping" sound is heard letting the user know that he or she can lift it off.

(Effects of the Invention) As explained above, the cartridge/carriage assembly of the present invention is suitable for use in inkjet printers, particularly thermal inkjet printers.

The cartridge/carriage assembly is easy to assemble and disassemble and allows for reproducible and accurate placement of the cartridge in the carriage. It should be noted that various changes and modifications will be readily apparent to those skilled in the art, and all such changes and modifications fall within the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is an exploded view of a carriage in an embodiment of the present invention, FIG. 3 is a perspective view of a spring pad in an embodiment of the present invention, and FIG. FIG. 4 is a front view of one part of a carriage in an embodiment of the present invention, FIG. 5 is a side view of a carriage in an embodiment of the present invention, and FIGS. 6a and 6b are an embodiment of the present invention. FIG. 7 is a diagram explaining the electrical connection in one embodiment of the present invention.
FIG. 8 is a diagram illustrating the parts shown in FIG. 4 with interconnect strips and contact strips installed; FIG.
The figure is a perspective view showing a cartridge in one embodiment of the present invention. 10: Cartridge/Carriage Assembly 12: Carriage 14: Cartridge 16: Interconnect Strip 18: Base Support 20: Chute 20b, 50a, 50b: Finger Grip 22:
Tightening means 24: Spring pad 26: Protrusion 27: Small protrusion 28: Conductive track 30: Dimple 44 Niblint head 46: Contact strip 48 Bi-concave contact pad 52a: V-shaped member 54: Lockout ear 56x: X reference pad 56y: Y reference pad 56z: Z reference pad 50r = rotation point 58: Side springs 60a, 60b: L-shaped member 60xs 60ys 60z: Reference surface 62 Ni-snap spring 64: Shelf-like member 67: Housing 67a: V-shaped surface 70 : Bearing 72 : Belt attachment 74 Nislider protrusion 76 : Carriage guide 84a, 84c : Lock tab 86 : Lock slot

Claims (1)

[Claims] A cartridge provided with the following (A) to (C):
carriage assembly. (A) Carriage. (B) A cartridge that has a print head on the bottom and is fixed at a predetermined position on the carriage: A contact that is connected to the print head is provided on the rear surface of the cartridge.
A strip is provided, a reference pad is provided on the side of the cartridge, and a ledge is provided on the rear surface for receiving a snap spring for locking the cartridge in the predetermined position. (C) Interconnection means for supplying electrical signals to said cartridge: said interconnection means having force-loading means for forcing electrical contacts provided thereon onto electrical contacts of said contact strip.