A connector for coupling a printhead to a circuit in a printer

Abstract: A connector for electricity connecting a first printhead (44) to an electric circuit (40) in a printer, comprising a body (42), first connector means (70) for connection to said circuit (40) and first receiver means (64) connected to said first connector means (70) and arranged to receive a coupling means (52) of said first printhead (44), and including second connector means (72) connected to second receiver means (66,68) for electricity connecting a second printhead (46) to said circuit (40) to replace said first printhead (44), said second receiver means being arranged to receive coupling means (54) of said second printhead (46) having a different electrical configuration from that of the coupling means (52) of said first printhead (44).

Description: The present invention relates to a connector coupling a printhead to a circuit in a printer. Known printers include a single printhead which is permanently mounted in the printer. In some such printers, a receptacle-type connector is permanently mounted in the printer to permit a printhead to be "plugged" into the connector. These receptacle-type connectors do not permit printheads having different plug configurations to be inserted into the connector. In particular, connectors known in the prior art are not capable of accepting printheads having different electrical connection requirements. In order to substitute a printhead in the printer having different electrical connection requirements, it is currently necessary to replace the entire connector. In some instances, this also requires the replacement of an entire printer carriage or circuit board on which the connector is mounted These changes have to be made by a field engineer or technician. Accordingly, a user cannot easily change the printhead in the printer without spending a considerable amount of time and money. From U.S.-A-4 778 291 there is known a dot printer including a printhead which is detachably fitted into a recess provided in the carriage. When the printhead has been attached to the carriage in this way the electrical connection can be completed. Also detachably attached to the printer is a system cartridge having a character font and firmwear program stored therein, whereby the number of dots printed can be changed by exchanging the printhead and the system cartridge. Each different printhead must be of the same shape so as to fit in the recess, and no information is given as to how electrical connection to the printhead is made. The present invention therefore seeks to provide a connector for permitting a user to selectively couple one of at least a first printhead or a second printhead to a circuit in a printer. According to the present invention there is provided a connector for electrically connecting a first printhead to an electric circuit, on a circuit board mounted on a printer carriage, said circuit being electrically connected to electric circuitry in a printer, the connector comprising a body, first connector means for connection to said circuit and first receiver means connected to said first connector means and arranged to receive a coupling means of said first printhead, characterized by second connector means connected to second receiver means for electrically connecting a second printhead to said circuit to replace said first printhead, said second receiver means being arranged to receive coupling means of said second printhead having a different electrical and physical configuration from that of the coupling means of said first printhead. One advantage of this invention is that it enables a user to quickly and easily change one printhead in a printer for another printhead having different electrical connection requirements without having to replace a printer carriage or a circuit board on the printer carriage. Another advantage of this invention is that it permits printheads having different electrical connection requirements to be interchanged without disturbing the quality of the printing of the printer. Yet another advantage of this invention is that it permits a printer to be easily and inexpensively manufactured, assembled and repaired because the printheads can be easily mounted in or removed from the printer. The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:- Fig. 1 is a partly broken away general perspective view of a printer, showing a print station and a printer carriage with a printhead connector; Fig. 2 is a fragmentary perspective view of a portion of the printer shown in Fig. 1, showing the printer carriage, the printhead connector and the first printhead in greater detail; Fig. 3 is an exploded view of dual printhead connector mounted on a circuit board, showing how either a first printhead or a second printhead can be selectively mounted in the printhead connector; Fig. 4 is a side view of the circuit board, taken in the direction of arrow A in Fig. 1, showing a first connection means and a second connection means or set of connection members in the dual printhead connector; and Fig. 5 is a partly broken away front view, taken in the direction of arrow F in Fig. 3, showing the first printhead in a raised position above the printhead connector. Fig. 1 is a general perspective view of a preferred embodiment of a printer 10. The printer 10 comprises a housing 12 and a controller 14 which provides electrical signals for controlling the operation of the printer 10. A suitable controller is comprised of model # 8052, manufactured by Intel Corporation of Santa Clara, California, as well as other associated electromechanical control electronics (not shown). The printer 10 also includes a print station 16 for printing the data 50 (Fig. 2) on a receipt document 18 (Figs. 1 and 2) at a receipt station 20 (Fig. 1) or on journal paper (not shown) at a journal station 24. In a preferred embodiment, the receipt document 18 is supplied from a paper supply roll 22 positioned at the print station 16. The journal paper (not shown) is conventionally supplied from a supply roll (not shown) which is mounted inside the journal housing 25 (Fig. 1). A slot 28 is provided at the left front of the printer 10 (when looking in the direction of arrow B in Fig. 1) in order to print on, for example, a slip (not shown) when the slip is inserted through the slot 28 into the print station 16 from the front of the printer 10. The print station 16 includes a printer carriage 30 which is coupled to traversing means 32 for traversing the printer carriage 30 in a side-to-side manner across the print station 16 and the journal station 24. The traversing means 32 includes the support rods 34A and 34B, respectively, which are conventionally secured to the housing 12. The printer carriage 30 is slidably mounted directly onto the support rods 34A and 34B by any suitable means, such as circular bushings 36 (Figs. 2 and 3). The traversing means 32 also includes a carriage drive motor (not shown) which is coupled to the controller 14. The carriage drive motor is coupled to the printer carriage 30 by a timing belt and pulleys (not shown). The controller 14 energizes the carriage drive motor to move the carriage 30 across the print station 16 in a side-to-side manner so as to effect printing at either the receipt station 20 or the journal station 24 (Fig. 1). As best shown in Figs. 1-3, the printer carriage 30 comprises a circuit board 38 having a circuit 40 mounted thereon. The circuit 40 is electrically interconnected to circuitry (not shown) of controller 14 by way of flexible cables 13 and associated interconnect hardware (not shown). The circuit board 38 is conventionally mounted to the carriage 30 by suitable fasteners, such as integral plastic snaps (not shown) or screws 41 (Fig. 3). The circuit board 38 has a dual printhead connector, hereinafter referred to as connector 42, secured thereto for coupling one of at least a first printhead 44 or a second printhead 46 to the circuit 40. In a preferred embodiment, the first printhead 44 is an Epson Model 90B 9-wire dot matrix printhead, manufactured by Epson Computer of Torrance, California. The second printhead 46 is an Epson'Model 240I 24-wire dot matrix printhead which is also manufactured by Epson Computer. The first and second printheads 44 and 46 cooperate with a platen 48 (Figs. 1 and 2) to print the data 50 on either the receipt document 18 or the journal paper (not shown) at the receipt station 20 (Fig. 1) or journal station 24, respectively. As best illustrated in Fig. 3, the first printhead 44 has first connection means comprising a single-sided pcb card edge finger or a connection member 52. In the embodiment being described, the second printhead 46 also has second connection means comprising a pair of single-sided pcb card edge fingers or a set of connection members 54. The connection member 52 has a first conductor 52-1, and the set of connection members 54 includes a second conductor 54-1 and a third conductor 54-2, as best shown in Fig. 3. The first, second and third conductors 52-1, 54-1 and 54-2 enable the first printhead 44 and the second printhead 46 to be coupled to the circuit 40. The connection member 52 and set of connection members 54 are generally planar and they depend from their respective printheads 44 and 46 approximately 1.27 centimeters as best illustrated by double arrow E in Fig. 5, which is shown in enlarged scale. The connection member 52 and set of connection members 54 also have a typical width (indicated by double arrow C in Fig. 3) of 2.26 centimeters and a typical thickness (indicated by double arrow D in Fig. 3) of 0.03 millimeters. It will be understood that the connection member 52 could be in the form of a plurality of connectors, if desired, and that the set of connection members 54 could be in the form of a single connector or a different number of separate connectors, if desired. A function of the circuit 40 (Fig. 3) is to connect the flexible cables 13 and controller 14 to the connector 42 and any other components (not shown), such as optical sensors (not shown), which may be mounted on the circuit board 38. Another function of the circuit 40 is to connect the flexible cables 13 and controller 14 (Fig. 1) to the connector 42 in order to couple the controller 14 to either the first or second printhead 44 or 46, respectively, depending on which printhead 44 or 46 is mounted in the connector 42. The circuit 40 has first contact means or a first set of nodes 56 (Fig. 3) for connecting the first printhead 44 thereto and second contact means or a second set of nodes 58 for connecting the second printhead 46 thereto. The connector 42 (Figs. 1-5) comprises a body 60 which is generally rectangular and which has dimensions of 2.54 centimeters x 1.27 centimeters x 3.81 centimeters in a preferred embodiment. The body 60 can be made from any suitable insulating material, such as plastic. The connector 42 also comprises receiving means 62 (Fig. 3) which provides a means for receiving either the connection member 52 or set of connection members 54. The receiving means 62 comprises a first aperture or slot 64 for receiving the connection member 52 in order to couple the first printhead 44 to the circuit 40. The receiving means 62 also comprises a second slot 66 and a third slot 68 for receiving the set of connection members 54 in order to couple the second printhead 46 to the circuit 40. The connector 42 further comprises first coupling means 70 (Fig. 4) which is associated with the first slot 64 of the receiving means 62. The function of the first coupling means 70 is to couple the first conductor 52-1 of connection member 52 to the first set of nodes 56 of the circuit 40 when the connection member 52 is inserted into the receiving means 62. The first coupling means 70 includes a first plurality of male conductors 70-1 (Figs. 3 and 5) which couple the first set of nodes 56 of circuit 40 to the first conductor 52-1 of connection member 52 when the connector 42 is mounted on the circuit board 38 and the connection member 52 is inserted into the first slot 64. The connector 42 also comprises second coupling means 72 (Fig. 4) which is associated with the second and third slots 66 and 68 of the receiving means 62. The function of the second coupling means 72 is to couple the second and third conductors 54-1 and 54-2 of the set of connection members 54 (Fig. 3) to the second set of nodes 58 of circuit 40 when the set of connection members 54 is inserted into the second and third slots 66 and 68, respectively. The second coupling means 72 (Fig. 4) includes a second plurality of male conductors 72-1 and 72-2 (Figs. 3 and 4). As best shown in Fig. 3, the second plurality of male conductors 72-1 and 72-2 couples the second set of nodes 58 to the first and second conductors when the connector 42 is mounted on the circuit board 38 and the set of connection members 54 is inserted into the second and third slots 66 and 68. Fig. 5 is a partly broken away front view, showing a row 72-1 of the second plurality of male conductors 72-1 and 72-2 integrally formed as part of the connector 42 and mounted onto the circuit board 38. The first and second plurality of male conductors 70-1, 72-1 and 72-2 depend from the bottom of the connector 42 (as viewed in Fig. 4) approximately 0.64 centimeters. The first and second plurality of male conductors 70-1, 72-1 and 72-2 are made of tin-plated berilyum-copper in a preferred embodiment, but they could be made of any suitable conductor which is capable of performing the same function. Also, the first and second plurality of male conductors 70-1, 72-1 and 72-2 are conventionally molded into the body 60 of the connector 42, and they may be secured to the circuit board 38 using conventional thru-hole printed circuit board technology, such as soldering. The operation of the printer 10 will now be described. For purposes of illustration, assume that the first printhead 44 is mounted in the first slot 64 of connector 42. In order to print the data 50 (Fig. 2) on the receipt document 18 at the print station 16 (Fig. 1), the controller 14 energizes the traversing means 32 to move the printer carriage 30 in a side-to-side manner. The controller 14 also energizes the circuit 40 by way of the flexible cables 13 which in turn energizes the first printhead 44 to print the data 50 on the receipt document 18. It may be desired to replace the first printhead 44 (Fig. 3) with the second printhead 46, for example, because the first printhead 44 is broken or because the second printhead 46 provides more desirable printing characteristics. In order to replace the first printhead 44 with the second printhead 46, a user or field engineer would remove the first conductor 52-1 of the connection member 52 from the first slot 64 in the connector 42. The user would then mount the second printhead 46 into the connector 42 by aligning and inserting the second and third conductors 54-1 and 54-2 of the set of connection members 54 into the second and third slots 66 and 68, respectively, as best shown in Fig. 3. After the second printhead 46 is mounted in the connector 42, the first and second conductors 54-1 and 54-2 become operatively coupled to the second set of nodes 58. The second printhead 46 will be coupled directly to the circuit 40 so that it can be energized by the controller 14. In a similar manner, the second printhead 46 can be removed from the connector 42 and replaced by the first printhead 44 if desired. Of course by way of an alternative the receiving means 62 could have slots 64, 66 and 68 which are shaped so as to be able to accommodate conductors 52-1, 54-1 and 54-2 which are not generally planar.

Claims: A connector for electrically connecting a first printhead (44) to an electric circuit (40), on a circuit board (38) mounted on a printer carriage (30), said circuit being electrically connected to electric circuitry in a printer, the connector comprising a body (42), first connector means (70) for connection to said circuit (40) and first receiver means (64) connected to said first connector means (70) and arranged to receive a coupling means (52) of said first printhead (44), characterized by second connector means (72) connected to second receiver means (66,68) for electrically connecting a second printhead (46) to said circuit (40) to replace said first printhead (44), said second receiver means being arranged to receive coupling means (54) of said second printhead (46) having a different electrical and physical configuration from that of the coupling means (52) of said first printhead (44). A connector according to claim 1, characterized in that at least one of said first (64) and second (66,68) receiver means comprises a slot (64) for receiving a tongue-like coupling means (52). A connector according to claim 1, characterized in that at least one of said first (64) and second (66,68) receiver means comprises a plurality of slots (66,68) for receiving coupling means comprising a plurality of tongue-like members (54). A connector according to either claim 2 or 3, characterized in that said first receiver means comprises a single slot (64) and said second receiver means comprises two parallel slots (66,68). A connector according to any preceding claim, characterized in that said first (70) and said second (72) connector means comprise male connection members (70-1,72-2). A connector according to any preceding claim, characterized in that said first (44) and second (46) printhead are wire matrix printheads. A print carriage for carrying a printhead in a printer, characterized by a connector according to any preceding claim. A printer characterized by a print carriage according to claim 7.

Inventors: BRULL ROBERT A, DEL SIGNORE II JAMES R, RABIDEAU DANIEL D, BRULL, ROBERT A., DEL SIGNORE II, JAMES R., RABIDEAU, DANIEL D.
Applicants: NCR INT INC, NCR INTERNATIONAL, INC.
Application year: 1991
Main classification: B41J25
IPC codes: H01R29, H01R33, H01R12, B41J25