KR960012777B1 - Printhead-carriage alignment and electrical interconnect clamping mechanism - Google Patents

Abstract

No summary.

Description

Printhead-carriage alignment and electrical interconnect clamping mechanism

1 is a perspective view of a carriage / cartridge assembly assembled with electrical interconnects.

2 is an enlarged side view of an elastomeric support in an electrical interconnect assembly and a cartridge.

3 is a partial cutaway perspective view of the elastic support.

4 is a front view of the carriage.

5 is a side view of a carriage without a cartridge.

FIG. 6A is a cross-sectional view of the assembly of FIG. 5 showing the cartridge inserted into the carriage but not locked in place.

FIG. 6B is a cross sectional view similar to FIG. 6A, showing the cartridge locked in place.

7 is an enlarged cross sectional view showing an electrical interconnect and an elastic support assembled within a cartridge;

8 is a side view with the cartridge chute removed to show the location of the electrical interconnects within the carriage.

9 is a perspective view of a cartridge showing printhead electrical contacts and reference pads providing electrical connection with resistors within the printhead.

* Explanation of symbols for main parts of the drawings

10: print cartridge / carriage assembly 12: carriage

14 cartridge 16: interconnect strip

18: base support 20: chute

20b, 50b, 50a, 68: holding part 22: binding device

24: spring pad 26: elastic projection

27: molded part 28: conductive wire

30: contact request 44: printhead

46: contact strip 48: contact pad

56: reference pad 58: side spring

60: L-shaped member 62: snap-spring

64: ledge member 66, 67: housing

70: bearing 72: belt attachment portion

74: slider bump 76: carriage guide

78: inserter arm 80: axis

TECHNICAL FIELD The present invention relates to ink-jet printers, and in particular, an electrical interconnect correction mechanism for controlling the printhead and alignment of the printhead and carriage. lock-in mechanism).

In ink-jet printing techniques, a printhead, consisting of a plurality of nozzles in a nozzle plate, is fluidly associated with a reservoir of ink. The printhead is mounted on one end of a print cartridge.

An interconnect device is provided for transferring electrical signals from the microprocessor in the printer to the printhead. For thermal ink-jet printers, such signals supply current to the resistors associated with the nozzles and therefore control the heating of certain resistors, which in turn form droplets of ink. Droplets of ink are fired through the nozzles toward the print media, such as paper. A special pattern of resistor heating controls the pattern of characters formed on the print media.

The print cartridge is supported in the carriage, and the carriage is adapted to move in two directions perpendicular to the movement of the print medium through the printer. Carriage movement is controlled by the motor and associated belt drive, which is controlled by the microprocessor.

Insertion of the ink-jet cartridge into the carriage often requires the use of both hands or two operations. In addition, many cartridge / carriage shapes do not provide simultaneous alignment in the X, Y and Z directions of the nozzle plate. Finally, the contact between the printhead and the interconnect device, and finally, the contact between the printhead and the interconnect device must be made reliably to ensure proper nozzle firing.

Thus, it would be desirable to have a cartridge / carriage assembly that includes the above advantages without the disadvantages of the prior art.

According to the invention, the printhead cartridge and carriage assembly comprise (a) a carriage, (b) a device for holding the printing cartridge in place within the carriage, and (c) a force loading means to be pressed against the cartridge. And an interconnect device for supplying electrical signals to the cartridge.

The cartridge has a front, bottom, sides, front, and bowel movements, and also has a printhead on the bottom surface, back contacts connected to the printhead, referencing pads on the sides, and the cartridge in place within the carriage. And a back lip for receiving a snap-spring for locking. The forced load device presses the interconnect device against the contacts of the cartridge.

The printhead cartridge / carriage assembly of the present invention requires only one hand of the operator to insert and lock the cartridge in place. The cartridge / carriage assembly also provides for simultaneous alignment in the X, Y and Z directions of the nozzle plate. Finally, the contact between the printhead and the interconnect device is secured each time the cartridge is inserted and locked in place, ensuring proper nozzle firing each time.

Referring now to the drawings, like reference numerals refer to like elements throughout, and FIG. 1 shows a print cartridge / carriage assembly. The assembly 10 consists of a carriage 12 in which a print cartridge 14 is locked in a suitable position. The interconnect strip 16 feeds electrical signals from the microprocessor (not shown) to the cartridge 14, as described in more detail below.

As shown in FIG. 2, the carriage 12 is composed of a base support 18 and a chute 20 coupled by a binding device 22 to the base support. The carriage 12 is advantageously composed of glass filled, carbon filled, polytetrafluoroethylene filled, silicon filled polycarbonate (glass-filled, carbon-filled, polytetrafluoroethylene-filled, silicon-filled polycarbonate).

The interconnect strip 16 and the spring pad 24 are inserted between the support 18 and the chute 20. The spring pad 24 is made of an elastic elastomer material, and is also made up of a plurality of resilient bumps 26, as shown in FIG. The spring pads 24 are seated in the depression 25 (shown in FIG. 4) in the carriage base support 18, behind a portion of the interconnect strip 16, as described in more detail below.

Base support 18 and chute 20 are aligned in proper relation by molded-in features 27, such as pips, which are formed with interconnect strips 16. Through the corresponding openings in the shell) and engage in opposed openings in the other member.

As shown more clearly in FIG. 8, the interconnect strip 16 consists of a strip of flexible dielectric material carrying a plurality of electrical conductors 28. Conducting wires 28 terminate in convex contact protrusions or dimples 30 of a special shape.

The projections 26 on the spring pad 24 are shaped similar to the contact requests 30 on the interconnect strip 16. As shown in FIG. 7, the spring pad protrusions 26 provide a forced load device for the contact requests 30 for pressing the contact requests 30 against the cartridge.

The cartridge 14 is composed of a front face 32, a bottom face 34, side faces 36, 38, a front face 40, and a bowel movement 42. The cartridge 14 is advantageously composed of an improved polyphenylene oxide.

The print head 44 is provided on the bottom face 34. The printhead 44 is composed of a plurality of resistors associated with a plurality of nozzles (not shown) molded in a nozzle plate (not shown). Ink (not shown) is stored in a reservoir inside the cartridge 14.

The cartridge 14 also includes a contact strip 46 on the back 42, which contacts the bottom surface to provide a plurality of conducting passages or traces with the resistors. 34) Surround yourself to the circumference. In particular, each resistor is supplied with an electrical signal along a unique conducting path. The contact strip 46 includes a plurality of convex contact pads 48, which are arranged in the same shape as the convex contact requests 30 on the interconnect strip 16. As described in more detail below, the immobilization of the cartridge 14 in the carriage 12 may cause the contact request portions 30 to provide an electrical passage from the microprocessor to the respective resistors in the print head 44. Engage with contact pads 48.

Contact strip 46 is composed of a flexible material having a plurality of electrical traces. Suitably, tape automated bond (TAB) circuits of the type manufactured and sold by 3M Company, Minneapolis, Minnesota, USA, are used.

The front face 32 of the cartridge 14 is equipped with a pair of finger grips 50a, 50b. The longer gripping portion 50a terminates at the V-shaped member 52a, which may be equipped with an arrow to indicate the correct direction of the cartridge. When the cartridge 14 is locked in the carriage 12, the cartridge is received up to the similarly shaped side of the carriage yarns providing a visual reference to the correct position. Lock-out ears 54 also act to prevent the cartridge 14 from being misplaced within the carriage 12.

Reference pads 56, shown more clearly in FIG. 9, are provided on the cartridge 14 near the base of the cartridge 14. In particular, two sets of reference pads 56 are provided, which consist of sculpted surfaces that align the nozzle plate in the X, Y and Z directions. The X reference pad 56x is a plane parallel to the side face 38. The carriage 12 is equipped with a side spring 58 that presses against the opposite side 36 to push the cartridge against one side of the chute 20, so there is only one X reference pad 56x. The Y reference pad is composed of the upper vertical surface 56y of the engraving surface. The Z reference pad is composed of the inner horizontal surface 56z of the engraving surface. The intersection of 56y and 56z consists of a pivot point or rotation point 56r, and the cartridge 14 rotates about the rotation point 56r during the locking operation.

Downwardly dependent L-shaped members 60a, b on support base 18 are cooperatively engaged in engagement with one of the reference pads 56, respectively. Engage with a ledge member 64 in the upper portion of the chute 20. The snap-spring 62 in the upper portion of the chute 20 engages with a ledge member 64 on the back of the cartridge 14.

The L-shaped members 60a, b provide a reference plane with which the reference pads 56 of the cartridge are supported. In particular, the reference pad 56x is supported relative to the reference surface 60x on the member 60a on the opposite side of the side spring 58. The reference pads 56y push back against the reference planes 60y (shown in FIG. 2). The reference pads 56z are supported downward on the reference plane 60z.

The snap-spring 62 is encased in the forming portion 66 of the carriage support base 18. The mating housing 67, seated on the snap-spring 62 when the base 18 and the chute 20 are assembled, includes an inner V-shaped face 67a, the inner V-shaped face 67a. Houses a similarly shaped surface 52a of the cartridge 14. The rear surface of the housing 66 is composed of a grip portion 68. Moreover, the holding part 20b is equipped also in the front of the cartridge chute 20. As shown in FIG.

The support 18 of the cartridge 12 includes a bearing 70, associated with a carriage rod (not shown). The carriage rod is positioned substantially parallel to the paper drive shaft (not shown) and also enables two-way movement of the carriage 12 along the paper drive shaft. The carriage 12 is moved by a belt (not shown) attached to the carriage by the belt attaching portion 72. The belt is attached to a carriage drive motor (not shown), the carriage drive motor being controlled by a microprocessor.

A reference device, or slider bump 74, is mounted on the face of the carriage guide 76. The weight of the carriage 12 preloads the slider bumps 74 against the carriage guides 76 so that they are always in constant contact. The slider bump 74 is composed of a low friction, wear resistant material and may also be a separat piece or a molded part of the carriage 12. The slider bump 74 serves to keep the printhead 44 constant and at a fixed distance from the print medium.

The carriage base 18 also includes an inserter arm 78 fixed within the shaft 80. The function of the inserter arm is related to the specific features that the assembly 10 mechanically triggers in a service station that exists between printing jobs and is also independent of the present invention.

The printhead locking mechanism is unique because it simultaneously aligns the nozzle plate in the X, Y, and Z directions and also aligns, wipes, and loads the contact pads of the electrical interconnect strip 16. Do. This can be accomplished without adding a bale, latch or lever arm as seen in other ink-jet printers. The alignment of the nozzle plate and the load on the interconnect strip 16 occur when the user rotates the cartridge 14 about the pivot point 56r in the direction of the arrow (Fig. 6A). The user does this by holding the cartridge thumb 50a and carriage forefinger 68 between the thumb and index finger.

The user should be able to easily insert the cartridge into the carriage chute 20 prior to gripping the cartridge 14 to the lock bottom position. Springs 58 and 62 that align cartridge 14 do not exert any force on the cartridge until the cartridge begins to rotate to the locked position (shown in FIG. 6B). This passes through an unobstructed passage so that the user can easily insert the cartridge into the pre-rotate position shown in FIG. 6A. However, the side-kicker spring 20 exerts a weak force when inserting the cartridge 14.

The cartridge 14 rotates about the reference pads 56, in particular about the point 56r. When the user rotates the cartridge 14, the alignment functions are performed before the electrical interconnect strip 16 is loaded. First, one side 36 of the cartridge 14 engages a molded-in carriage side spring 58. The spring 58 references the cartridge 14 in the X direction by pushing the cartridge sideways until the X reference pad 56x contacts the X reference pad 60x on the cartridge. ) As a result, the nozzle plate is accurate in the X direction and aligned without inclination.

The next action that takes place is alignment in the Z direction. When the back ledge 64 of the cartridge 14 collides with the back metal snap-spring 62, the spring remains until the Z reference pads 56z contact the Z reference pads 60z on the cartridge 12. Push the cartridge in the Z direction. As a result, the electrical interconnect 16 and the nozzle plate are accurate in the Z direction and are registered without inclination.

As the cartridge 14 continues to rotate in position about the rotation point 56r, the electrical interconnect concave contact pads 48 on the cartridge contact 46 may cause convex contact requests on the carriage interconnect strip 16 to rise. Slightly wiped by 30). This provides improved reliability over interconnects as required on prior art printers, since oxides and contaminants are wiped at contacts 30 and 48 before interconnect 16 is loaded.

The wiping action is accompanied by the alignment of the cartridge electrical contact pads 48 in the X direction. This occurs when the outer rear heel lock tabs of the cartridge engage the sides 86a and c of the heel lock slot 86 on the carriage 12. The interconnect strip 16 on the carriage 12 is accurately referenced to the heel lock slot 86 by pins 27 to provide the required alignment of the interconnect strip with the electrical contact pads 48 of the cartridge. Prepare. The contact strip 46 is bound to the cartridge 14 by glue or adhesive or the like and is referenced by a granulator.

Finally, the cartridge 14 is exactly aligned in the Y direction. The rubber spring pad 24 of the electrical connection on the cartridge 12 must be deformed a suitable distance in the Y direction to maintain the required contact force. In the back 42 of the cartridge 14, the rubber spring 24 is provided with electrical contacts 30 and 48 such that the Y reference pad 56y on the cartridge contacts the Y reference pads 60y on the carriage. Push back about. This maintains the necessary force on the contact pads 48 located on the contact strip 46 on the back 42 of the cartridge 14. It also controls the rotational alignment of the nozzles as well as providing an accurate Y registration of the nozzle plate.

In the front portion 32 of the cartridge 14, the necessary contact force in the Y and Z directions is maintained by the rear snap-spring 62. As the cartridge 14 rotates to the latched position, the rear end 64 of the cartridge 14 deforms the rear snap-spring 62 and also over-center point 62a on the snap-spring. Pass through (Fig. 6a). The snap-spring 62 is designed to exert a force of about 70% in the Y direction. This is the force required to maintain the electrical interconnect 16 in the back 42 of the cartridge 14.

As the cartridge 14 passes through the out-of-center point 62a on the rear snap-spring 62, the cartridge causes a snap to be heard to inform the user that the cartridge is in the proper lock position. . The force of the rubber interconnect spring pad 24 is sufficient to secure the cartridge in the precisely aligned position as it is experienced during normal printing.

To remove the cartridge 14 from the carriage 12, the user simply rotates the cartridge by holding the cartridge forefinger 50b and the carriage thumb 20b between the thumb and forefinger. The rear ledge 64 on the cartridge 14 deforms the rear snap-spring 62 until the cartridge is centered in the unlocked position. An audible click will now be heard to inform the user that the cartridge 14 can now be lifted out of the carriage.

The print cartridge / carriage assembly described herein is useful for ink-jet printers, in particular thermal ink-jet printers.

The foregoing has described an ink-jet print cartridge / carriage assembly that is easy, assembled and disassembled, with reproducible and accurate registration in the carriage of the cartridge. Various obvious changes and changes will be readily apparent to those skilled in the art, and all such changes and changes are intended to be included within the scope of the invention as defined by the appended claims. To be considered.

Claims (24)

Apparatus for fixing (a) the carriage 12, (b) the printing cartridge 14 in place within the carriage, in a printhead cartridge and carriage assembly 10 for an ink-jet printer for printing on a print medium. (62), and (c) an interconnecting device (16) comprising a forced load device (24) to be pressed against the contact portion of the cartridge and for supplying electrical signals to the cartridge, the cartridge front surface ( 32, a printhead 44 on the bottom, a contact strip on the back connected to the printhead, having a bottom face 34, sides 36 and 38, a front face 40 and a back face 42; Reference pads 56 on the sides, and a recess 64 on the back for receiving a snap-spring 62 for locking the cartridge in place, the fastening device being adapted to the snap-spring and The cartridge And a device (60) for receiving the reference pads on the printhead. The printhead cartridge and carriage assembly of claim 1, wherein the carriage consists of a support base (18) and a chute (20) coupled to the support base, the chute configured to receive the cartridge. 3. The press according to claim 2, wherein the chute is adapted to press against the corresponding side of the cartridge to engage the X reference pad 56x of the cartridge with respect to the X reference pad 60x of the cartridge within one side of the chute. A printhead cartridge and carriage assembly comprising a spring device (58). The printhead cartridge and carriage assembly of claim 1, having devices 20b, 50a, 50b, 68 and reference faces 56, 60 to assist the carriage and the cartridge in locking and unlocking the cartridge. . The printhead cartridge and carriage assembly of claim 4, wherein the carriage base comprises finger-engaging pads (20b, 68) on the base. 5. The printhead cartridge and carriage assembly of claim 4, wherein the cartridge has a visible reference surface (52a) and the carriage base has a corresponding surface (67a) for receiving the reference surface. A print head cartridge and carriage assembly according to claim 4, wherein said cartridge is provided with finger-engaging pads (50a, 50b) on said cartridge. 5. The printhead cartridge and carriage assembly of claim 4, comprising a bailless self-locking device. 9. The printhead cartridge and carriage assembly of claim 8, wherein the bailless self-locking device is comprised of forces provided by the rear springs (62) and the interconnecting spring pads (24). 10. The printhead cartridge and carriage assembly of claim 9, wherein the forces provide reproducible, accurate, and tiltless referencing of the cartridge and the carriage. 11. The printhead cartridge and carriage assembly of claim 10, wherein said locking and unlocking of said cartridge within said carriage are accomplished in a single operation to substantially simultaneously provide said referencing and establish said electrical interconnections. 5. The printhead cartridge and carriage assembly of claim 4, wherein said cartridge comprises closure teeth (54) to prevent said cartridge from being improperly positioned within said carriage base. The printhead cartridge and carriage assembly of claim 1, further comprising a bearing device (70) for enclosing the carriage rod to move the carriage in two directions within a direction perpendicular to the direction of the print medium. 14. The printhead cartridge and carriage assembly of claim 13, further comprising a belt attachment device (72) adjacent said bearing device to enable attachment of the belt therein in association with the motor for controlled movement of the carriage. A printhead cartridge and carriage assembly as set forth in claim 1, further comprising a catcher (74) for maintaining the printhead at a fixed distance from the print media. A printhead cartridge and carriage assembly 10 for an ink-jet printer for printing on a print medium, comprising: (a) a carriage consisting of a support base 18 and a chute 20 bound to the support base 18; 12), (b) a veilless self-locking device 62 for securing the printing cartridge 14 in place in the carriage, and (c) for pressing the interconnector against the contact of the cartridge. An interconnecting device 16 for forcing an electrical signal to the cartridge, comprising a forced load device 24, the chute being adapted to receive the cartridge and also having an X reference of the cartridge within one side of the chute. A spring device 58 for pressing the corresponding side of the cartridge to engage the pad 56X with respect to the X reference pad 60x of the carriage, the support base being A bearing device 70 for enclosing the carriage rod to move the carriage in two directions within a direction perpendicular to the direction of the print medium, and further comprising a belt therein associated with the motor for controlled movement of the carriage. A belt attachment device 72 adjacent the bearing arrangement to enable attachment of the cartridge, wherein the cartridge has a front face 32, a bottom face 34, sides 36, 38, a front face 48 and a back face 42. And having the printhead 44 on the bottom, the contact strip 46 on the back connected to the printhead, the reference pads 56y, 56z on the sides, and the cartridge in place. A backing 64 on the back for receiving a snap-spring 62 for the holding device, wherein the fixing device comprises a device 60y, 60z for receiving the snap-spring and the reference pads on the cartridge. A printhead cartridge and carriage assembly comprising finger-engagement devices (20b, 50a, 50b, 68) to help the carriage and the cartridge to lock and unlock the cartridge. 17. The printhead cartridge and carriage assembly of claim 16, wherein the carriage base comprises finger-engaging pads (20b, 68) on the base. 17. The printhead cartridge and carriage assembly of claim 16, wherein the cartridge has a visible reference surface (52a) and the carriage base has a corresponding surface (67a) for receiving the reference surface. 17. A print head cartridge and carriage assembly as set forth in claim 16, wherein said cartridge is provided with finger-engaging pads (50a, 50b) on said cartridge. 17. The printhead cartridge and carriage assembly of claim 16, wherein said baleless self-locking device is comprised of forces provided by a rear spring (62) and an interconnecting spring pad (24). 21. The printhead cartridge and carriage assembly of claim 20, wherein the forces provide reproducible, accurate, and tiltless referencing of the cartridge and the carriage. 22. The printhead cartridge and carriage assembly of claim 21, wherein the locking and unlocking of the cartridge within the carriage is accomplished in a single operation to substantially simultaneously provide the referencing and establish the electrical interconnection. 17. The printhead cartridge and carriage assembly of claim 16, wherein said cartridge comprises closure teeth (54) to prevent said cartridge from being improperly positioned within said carriage base. 17. The printhead cartridge and carriage assembly of claim 16, further comprising a closing device (74) for maintaining the printhead at a fixed distance from the print media.

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