JP3069105B2 - Cartridge / carriage assembly - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to ink jet printers, and more particularly, to an alignment between a printhead and a carriage, and a lock-in mechanism for an electrical connection that controls the printhead.

Prior Art and its Problems In ink-jet printing technology, the printhead has a plurality of nozzles in a nozzle plate, but is hydrodynamically related to the ink reservoir. The printhead is mounted on one end of the print carriage and the ink reservoir is located inside the carriage.

Interconnecting means are provided for transmitting electrical signals from a microprocessor in the printer to the printhead. In the case of thermal ink jet printers, these signals supply current to a resistor associated with the nozzle to control the heating of a particular resistor, thereby forming an ink droplet. The ink droplets are fired through a nozzle toward a print medium, such as paper. By heating the resistor according to a specific pattern, a pattern such as a character formed on the print medium is controlled.

The print cartridge is supported by a carriage, which moves bidirectionally at right angles to the movement of the print media past the printer. The movement of the cartridge is controlled by a microprocessor, with the motor controlled by a microprocessor, and an associated belt drive.

Inserting an ink jet cartridge into a carriage often requires the use of two hands or two operations. Further, many cartridge / carriage configurations do not allow the nozzle plate to be simultaneously aligned in the X, Y, and Z directions. Finally, the contact between the printhead and the interconnecting means must be reliable in order for the nozzle to fire properly.

OBJECTS OF THE INVENTION It is an object of the present 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 comprises: (a) a carriage; (b) means for securing a print cartridge in place within the carriage; Means for supplying an electrical signal to the cartridge, the means comprising force loading means for pressing the interconnecting means against the cartridge.

The cartridge has an upper surface, a lower surface, a side surface, a front surface, and a rear surface. The lower surface has a printhead, the rear surface has contacts connected to the printhead, the side surfaces have reference pads, and the rear surface has a lip for receiving a snap spring that locks the cartridge in place in the carriage. The securing means comprises a snap spring and means for receiving a reference pad on the cartridge. The force loading means presses the interconnection means against the cartridge contacts.

With this cartridge / carriage assembly, the operator need only use one hand to insert and lock the cartridge in place. Furthermore, this cartridge /
The carriage assembly can simultaneously position the nozzle plate in the X, Y, and Z directions. Finally, contact between the printhead and the interconnecting means is ensured each time the cartridge is inserted and locked in place, thereby ensuring that the nozzles fire correctly each time.

EXAMPLES Referring now to the drawings, like reference numerals refer to like elements throughout. Printed with the whole as 10
The cartridge / carriage assembly is shown in FIG. The cartridge / carriage assembly 10 includes a carriage 12, on which a cartridge 14 is depicted locked in place. Interconnect strip
16 provides electrical signals to the cartridge 14 from a microprocessor (not shown), as described more fully below.

As shown in FIG. 2, the carriage 12 is mounted on a base support 18.
And a chute 20 attached thereto by fastening means 22. Carriage 12 is preferably glass-filled, carbon-filled, polytetrafluoroethylene-filled, silicon-filled polycarbonate.

Interconnect strip 16 and spring pad 24 are sandwiched between base support 18 and chute 20. The spring pad 24 is made of a resilient elastomeric material and has a plurality of resilient protrusions 26, as can be seen in FIG. Spring pad
24 is received in a recess 25 (shown in FIG. 4) in the carriage base support 18 after a portion of the interconnect strip 16, as described more fully below.

The base support 18 and the chute 20 are aligned in the correct relationship by a molded shape such as a pip 27. The small projections 27 each engage a corresponding hole in another member through a corresponding hole in the interconnect strip 16.

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

The protrusion 26 on the spring pad 24 is
The same pattern as the dimple 30 which is the contact pattern of FIG. As can be seen in FIG. 7, the projection 26 of the spring pad acts as a force-loading means for the dimple 30 in contact with the spring pad and presses the dimple 30 against the cartridge 14.

The cartridge 14 has an upper surface 32, a lower surface 34, side surfaces 36 and 38, and a front surface.
40, and a rear surface 42. Cartridge 14 is preferably made from a modified polyphenylene oxide.

The print head 44 is provided on the lower surface 34. The print head 44 includes a plurality of nozzles (not shown) formed on a nozzle plate (not shown) and a plurality of resistors (not shown) associated therewith. Ink (not shown) is stored in an ink reservoir inside the cartridge 14.

The cartridge 14 also has a rear surface 42 as shown in FIG.
A contact strip 46 is also provided. Contact strip 46 is wrapped around lower surface 34 and provides a plurality of conductive paths or traces to the resistor. In particular,
Each resistor is supplied with an electrical signal along a separate conductive path. The contact strip 46 includes a plurality of concave contact pads 48, which are arranged in the same pattern as the convex contact dimples 30 of the interconnect strip 16. As described in more detail below, locking cartridge 14 in carriage 12 causes dimple 30 to mate with concave contact pad 48 to form an electrical path from the microprocessor to each resistor in printhead 44. .

Contact strip 46 is constructed of a flexible material having a plurality of electrical lines thereon. Preferably,
Adopts a tape automated bond (TAB) circuit manufactured and sold by 3M (Minneapolis, MN, USA).

For example, as shown in FIG. 1, the upper surface 32 of the cartridge 14 is provided with a pair of finger grips 50a, 50b. A V-shaped member 52a is provided at the end of the larger finger grip 50a. Here is cartridge 1
An arrow can be provided to orient 4 in the correct direction. When locking the cartridge 14 to the carriage 12, the cartridge is received on the same shaped surface of the carriage as a visual reference in the correct orientation. The lockout ear 54 also serves to prevent the cartridge 14 from being misoriented within the carriage 12.

The reference pad 56 is located near the base of the cartridge 14, as can be seen more clearly in FIG. More specifically, two sets of reference pads 56 are provided. These reference pads 56 constitute a surface shaped to align the nozzle plate in the X, Y, and Z directions shown in FIG.
As will be apparent from the description below, one of the sets of reference pads 56 has an X reference pad 56x for alignment in the X direction and a Y reference pad 56y for alignment in the Y direction, and one in the Z direction. Z reference pad 56z for alignment
Are included. On the other hand, the other of the set of reference pads 56 has an X reference pad 56 for positioning in the X direction.
There is no x, each Y to align in the Y direction
Only two surfaces which are Z reference pads 56z for positioning in the Z direction with the reference pad 56y are included. X reference pad 56x
Is a surface parallel to the side surface 38. (Since the carriage 12 is provided with a side spring 58 that presses the opposite side surface 36 to press the cartridge 14 against one side of the chute 20, there is only one X reference pad 56x.) The Y reference pad 56y is (Z−
On the top vertical plane (parallel to the X plane) and Z reference pad 56z
Is in the internal horizontal plane (parallel to the XY plane). At the junction where the upper vertical plane and the internal horizontal plane intersect, there is a pivot, ie, two (for two sets of reference pads 56).
A rotation point 56r is provided around which the cartridge 14 rotates during a lock-in operation.

L-shaped members 60a, 6 attached downward to the base support 18
Ob engages cooperatively with one of the reference pads 56, respectively. A snap spring 62 on the top of chute 20 engages a ledge 64 on rear surface 42 of cartridge 14.

The L-shaped members 60a, 60b have reference surfaces 60x, 60y, 60z on which the reference pad 56 of the cartridge 14 is pressed. Specifically, the X reference pad 56x presses and abuts on the reference surface 60x of the L-shaped member 60a far from the side spring 58. Each Y reference pad 56y presses against the reference surface 60y of each L-shaped member, and each Z reference pad 56z presses against the reference surface 60z of each L-shaped member.

The snap spring 62 is housed in a molded housing 66 of the carriage base support 18. The mating housing 67 is disposed above the snap spring 62 when the base support 18 and the chute 20 are assembled, but has an inward V-shaped surface 6 for receiving the same surface 52a of the cartridge 14.
7a. Following the housing 66 is a finger grip 68. A finger grip 20b is also provided on the front surface of the chute 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 mounted substantially parallel to the paper drive axis (not shown) along which the carriage 12 can be moved in both directions. The carriage 12 is moved by a belt (not shown) attached to the carriage by a belt attachment 72. The belt is mounted on a carriage drive motor (not shown), which is controlled by a microprocessor.

The reference means, that is, the slider protrusion 74 is
It is on the surface of guide 76. The slider protrusion 74 applies a preload to the carriage guide due to the weight of the carriage 12, thereby keeping the degree of contact constant. The slider protrusion 74 is made of a material with low friction and low wear, and may be a separate part or a part formed on the carriage 12 by molding. The slider protrusion 74 serves to keep the print head 44 at a fixed and constant distance from the print medium.

The carriage base support 18 also includes an interposer arm 78 fixed to a shaft 80. The function of the inserter arm involves the cartridge / carriage assembly 10 mechanically triggering certain features of the service station that reside between printing operations and is not relevant to the present invention.

This lock-in mechanism of the printhead is unique because it aligns the nozzle plate in the X, Y, and Z directions simultaneously and aligns, wipes, and loads the contact pads on the electrical interconnect strip 16. It is believed that there is. This can be a bail, latch, or lever lever as found in other inkjet printers.
This is achieved without providing a separate arm. Alignment of the nozzle plate and loading of the interconnect strip 16 may be accomplished by the user moving the cartridge 14 about the point of rotation 56r, as indicated by arrow 82 (6a
This is performed when rotating in the direction shown in FIG. The user does this by grasping the finger grip 50a of the cartridge and the finger hold 68 of the carriage with his thumb and index finger.

Before the cartridge can be pushed into its locked-in position, the cartridge must be able to easily drop onto the chute. The side spring 58 and the snap spring 62 for aligning the cartridge 14
Apply no force to the cartridge until the starts to rotate to the lock-in position (shown in FIG. 6b). Therefore, an unobstructed path that facilitates the user to drop the cartridge 14 to the position before the rotation shown in FIG. 6a is formed. However, the side spring 58 exerts a light force when the cartridge 14 is inserted.

The cartridge 14 rotates around a reference pad 56, specifically around a rotation point 56r. User Cartridge 14
, The alignment function is performed before the electrical interconnect strip 16 is loaded. Initially, one side 36 of the cartridge 14 engages a side spring 58 formed on the carriage side by molding. The side spring 58 provides a reference in the X direction 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 reliable positioning of the nozzle plate in the X direction is performed.

The next operation that occurs is Z-direction alignment. When the rear ledge 64 of the cartridge 14 encounters the rear metal snap spring 62, the spring will cause the Z reference pad 56z to
The cartridge is pushed in the Z direction until it comes into contact with the reference surface 60z as the reference pad. As a result, both the interconnect strip 16 and the nozzle plate are accurate and error free in the Z direction.

As the cartridge 14 continues to rotate about the point of rotation 56r to a predetermined position, the concave contact pads 48 for electrical interconnection of the contact strips 46 on the cartridge are dimples, which are the convex contacts of the interconnect strip 16 of the carriage. 30 lightly wiped off. This provides improved reliability over dimpled interconnects of conventional printers because oxide and contaminants are wiped from dimples 30 and concave contact pads 48 before interconnect strip 16 is loaded.

Subsequent to the wiping operation, the concave contact pads 48 for electrical connection on the cartridge are aligned in the X direction.
This locks the heel on the outside rear of the cartridge 14
This occurs when the tabs 84a, 84c engage the sides 86a, 86c of the locking slot 86 in the heel of the carriage 12. The interconnect strip 16 of the carriage 12 is accurately referenced to the locking slot 86 by the small protrusion 27, thereby connecting the interconnect strip 16 to the concave contact pad 48 of the cartridge 14.
And necessary alignment. Contact strip 46
The glue is secured to the cartridge 14 by something like glue or adhesive and is referenced by an assembly machine.

Finally, the cartridge 14 is accurately aligned in the Y direction. The rubber spring pad 24 for electrical interconnection on 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 pad 24 pushes the dimple 30 and the concave contact pad 48 in electrical contact, causing the Y reference pad 56 y of the cartridge 14 to contact the reference surface 60 y of the carriage 12. This applies the necessary force to the concave contact pads 48 disposed on the contact strips 46 at the rear surface 42 of the cartridge 14. Also,
In addition to being able to accurately position the nozzle plate in the Y direction, the position of the nozzle in the rotational direction can be adjusted.

On the upper surface 32 of the cartridge 14, the necessary forces in the Y and Z directions are maintained by a rear snap spring 62. cartridge
As 14 rolls into the lock-in position, the cartridge
The rear lip or shelf 64 of the 14
Is displaced to get over the center point 62a (FIG. 6a) of the snap spring. The snap spring 62 is designed to apply about 70% of its force in the Y direction. This is the force required to hold the interconnect strip 16 for electrical interconnection to the rear surface 42 of the cartridge 14.

When the shelf 64 of the cartridge 14 passes through the midpoint 62a of the rear snap spring 62, the cartridge emits an audible "click" to inform the user that the cartridge 14 has entered the correct lock-in position. . The force of the interconnecting spring pads 24 is adequate to hold the cartridge in its precise alignment under the high acceleration and impact loads that the cartridge 14 experiences in normal printing conditions.

To remove the cartridge 14 from the carriage 12, the user may simply turn the finger grip 50b of the cartridge and the finger grip 20b of the carriage with their thumb and forefinger while applying force. The shelf member 64 of the cartridge 14 is located at the center of the rear snap spring 62.
The rear snap spring 62 is displaced until the cartridge 14 is in the unlocked position beyond 62a. cartridge
14 hears a "snap" informing the user that it can now be lifted from carriage 12 for disposal.

As described above, the cartridge / carriage assembly of the present invention is suitable for use in an ink jet printer, especially a thermal ink jet printer.

The cartridge / carriage assembly is easy to assemble and disassemble, and allows the cartridge to be accurately and reproducibly installed on the carriage. 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 invention.

[Brief description of the drawings]

1 is a perspective view of one embodiment of the present invention, FIG. 2 is an exploded view of a carriage in one embodiment of the present invention, FIG. 3 is a perspective view of a spring pad in one embodiment of the present invention, FIG. FIG. 4 is a front view of one part of the carriage in one embodiment of the present invention, FIG. 5 is a side view of the carriage in one embodiment of the present invention, FIGS. 6a and 6b.
FIG. 7 is a diagram for explaining the operation of one embodiment of the present invention. FIG. 7 is a diagram for explaining the electrical connection in one embodiment of the present invention.
FIG. 9 is a view showing a state in which an interconnect strip and a contact strip are attached to one part shown in FIG. 4, and FIG. 9 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: Chutes 20b, 50a, 50b: Finger grip 22: Tightening means 24: Spring pad 26: Projection 27: Small protrusion 28: Conductive line 30: Dimple 44: Print head 46: Contact strip 48: 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 spring 60a, 60b: L-shaped member 60x, 60y, 60z: Reference surface 62: Snap spring 64: Shelf member 67: Housing 67a: V-shaped surface 70: Bearing 72: Belt mounting 74: Slider Projection 76: Carriage guide 84a, 84c: Lock tab 86: Lock slot

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jay Paul Harmon Vancouver Northeast, Twenty-Second Twenty-Second Circle 9012, Washington, USA Pine Creek Street 9517 (56) Reference: JP-A-61-25849 (JP, A) JP-A-60-204342 (JP, A) JP-A-60-204343 (JP, A) JP-A-60-204329 (JP, A) JP-A-62-234942 (JP, A) JP-A-61-164742 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/01 B41J 2 / 05 B41J 25/34

Claims (6)

(57) [Claims] A cartridge / carriage for mounting a cartridge having a print head in a printer.
An assembly comprising: (a) carriage means including base support means having a mechanism for mounting the cartridge; and (b) a three-way reference surface for receiving the cartridge provided below the base support means. Reference means, (c) in the cartridge, a reference system for engaging with the reference means, provided at a lower portion of a surface which is to be brought into contact when the cartridge is attached to the base support means, (d) the reference system (E) first electrical connection means for supplying a control signal to the cartridge, provided on a surface of the base support means, which is to be brought into contact when the cartridge is mounted on the base support means; In the cartridge, when the cartridge comes into contact with the cartridge when the cartridge is attached to the base support means, Second electrical connection means provided on a fixed surface for supplying a control signal to the print head; (f) a shelf-like member provided on the cartridge; (g) the reference system of the cartridge is When the cartridge is engaged with the reference means of the base support means and the cartridge rotates with reference to the engagement portion and comes into contact with the base support means, the base support means engages and locks with the shelf member. (H) a chute provided on the base support means, wherein the cartridge is dropped on the chute to engage with the reference system of the cartridge and the reference means of the base support means. Allowing the cartridge to rotate relative to the base support means about a point of rotation provided by the reference system and the reference means. Cartridge / carriage having a chute for
assembly. 2. The method according to claim 1, wherein the chute has side spring means which does not bias the cartridge until rotation starts after the reference system of the cartridge is engaged with the reference means of the base support means. The cartridge / carriage assembly of claim 1, wherein 3. The apparatus according to claim 1, wherein said base support means includes a fingerholding member and said carriage includes a finger grip for performing said rotation and locking with a finger. 3. The cartridge / carriage assembly of claim 2. 4. The cartridge / carriage assembly according to claim 1, wherein said holding means has a snap spring engaged with said shelf member. 5. The reference means comprises a pair of downwardly-facing, spaced apart, generally opposed L-shaped members, the reference system including two sets of similar reference pads,
5. The cartridge / carriage assembly according to claim 1, wherein the reference pad is disposed at a lower portion of the cartridge at a position substantially symmetrical with respect to the print head. . 6. The cartridge / carriage assembly according to claim 1, wherein said first electrical connection means has a plurality of convex contacts.