Abstract:
The present invention provides a recording apparatus having a cartridge mounting member to which a cartridge is detachably mountable, having a connector adapted to effect electrical connection to the cartridge and having a first attached portion for receiving an attaching member for attaching the connector to the cartridge mounting member, a second attached portion provided on the cartridge mounting member and adapted to receive the attaching member when the connector is attached to the cartridge mounting member, and a substrate adapted to hold the connector and having a configuration in which the substrate is not contacted with the attaching member when the first and second attached portions are interconnected by the attaching member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a construction and a method regarding electrical connection between a head mounting member of a recording apparatus and a head member detachably mountable on the head mounting member. 
     2. Related Background Art 
     In ink jet printers, conventionally, in many cases, electrical contact between a body side carriage and a detachable head has been effected by connecting a projection of a flexible cable provided on the carriage to a contact pad portion of a head cartridge. 
     In this case, a rubber pad having a projection is provided on a rear surface of the flexible cable so that positional error of a contact portion is absorbed by elasticity of rubber, thereby stabilizing contact pressure between the contacts. However, since the error absorbing ability of the rubber pad is poor and the elasticity of rubber varies with change in temperature, it may be difficult to obtain a positive contacting condition. 
     To cope with this, as disclosed in Japanese Patent Application Laid-open No. 9-86012 (1997), there is provided a technique in which a connector comprised of a plurality of metal connection pieces is attached to a carriage and the connector and a head cartridge are electrically connected to each other. 
     According to such a technique, the positional error absorbing range is increased by elasticity of the metal connection pieces, and, since the metal connection pieces are rocked completely independently, all of the contacts can be maintained in the positive contacting condition. 
     However, in the above-mentioned conventional example, since the metal connection pieces are arranged laterally in a line, when contacts are further increased, a length of the connector is increased accordingly, thereby making the head cartridge and the carriage more bulky. 
     Further, as the number of contacts is increased, a reaction force of contact pressure generated in each contact becomes great considerably. That is to say, if the connector is not secured to the carriage by a force overcoming such reaction force, the contacting condition becomes unstable. 
     In the past, since a portion of a contact substrate to which the connector is welded was secured to the carriage by screws, the contact substrate was flexed by the reaction force, with the result that the contacting condition might be unstable and/or the contact substrate might be damaged. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a recording apparatus in which, while an external force caused during mounting of a head member is being prevented from acting on an electrical part attaching member to which electrical parts for electrically connecting between the head member and a head mounting member are attached, the electrical parts attached to the electrical part attaching member can positively be secured to the head mounting member. Further, an additional object is to provide a recording apparatus in which the electrical parts can be positioned on and secured to the head mounting member with high accuracy. 
     Another object of the present invention is to provide a recording apparatus of serial type in which, while an external force caused during mounting of a head member is being prevented from acting on an attaching substrate to which a connector for electrically connecting between the head member and a carriage are attached, the connector attached to the attaching substrate can positively be secured to the carriage. Further, an additional object is to provide a recording apparatus of serial type in which the connector can be positioned on and secured to the carriage with high accuracy. 
     A further object of the present invention is to provide a recording apparatus of full-line type in which, while an external force caused during mounting of a full-line head is being prevented from acting on an attaching substrate to which a connector for electrically connecting between the full-line head and a head mounting member are attached, the connector attached to the attaching substrate can positively be secured to the head mounting member. Further, an additional object is to provide a recording apparatus of full-line type in which the connector can be positioned on and secured to the head mounting member with high accuracy. 
     A still further object of the present invention is to provide a recording apparatus having a cartridge mounting member to which a cartridge is detachably mountable, comprising a connector adapted to effect electrical connection to the cartridge and having a first attached portion for receiving an attaching member for attaching the connector to the cartridge mounting member, a second attached portion provided on the cartridge mounting member and adapted to receive the attaching member when the connector is attached to the cartridge mounting member, and a substrate adapted to hold the connector and having a configuration in which the substrate is not contacted with the attaching member when the first and second attached portions are interconnected by the attaching member. 
     A further object of the present invention is to provide an ink jet recording apparatus for effecting recording by a head cartridge detachably mounted to a reciprocal carriage, wherein a contact substrate including a connector having a number of elastic metal connection pieces is attached to the carriage, and contact pads corresponding to the elastic metal connection pieces are provided on the head cartridge, and further wherein a housing portion of the connector is directly secured to the carriage by an attaching member and the contact substrate is configured to have an escape portion not interfered with the attaching member. 
     A still further object of the present invention is to provide an ink jet recording apparatus for effecting recording by a plurality of head cartridges detachably mounted to a reciprocal carriage, wherein a contact substrate including a plurality of connectors each having a number of elastic metal connection pieces is attached to the carriage, and contact pads corresponding to the elastic metal connection pieces are provided on each of the head cartridges, and further wherein a positioning spacer is inserted between the connectors and the contact substrate so that positioning between the connectors and the contact substrate is effected via the spacer, and housing portions of the connectors are directly secured to the carriage by attaching members and the contact substrate is configured to have escape portions not interfered with the attaching members. 
     The other object of the present invention is to provide a method for attaching an electrical substrate to a cartridge mounting member to which a cartridge is detachably mountable, comprising the steps of providing, on a connector for effecting electrical connection to the cartridge, a first attached portion for receiving an attaching member for attaching the connector to the cartridge mounting member, providing, on the cartridge mounting member, a second attached portion for receiving the attaching member when the connector is attached to the cartridge mounting member, and providing an escape portion in the substrate for holding the connector so that the substrate does not interfere with the attaching member when the first and second attached portions are secured to each other by the attaching member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view for explaining a main body side carriage according to a first embodiment of the present invention; 
     FIG. 2 is a plan view of a connector of FIG. 1; 
     FIG. 3 is a sectional view of the connector taken along the line  3 — 3  in FIG. 2; 
     FIG. 4 is a perspective view for explaining a head cartridge opposed to the carriage of FIG. 1; 
     FIG. 5 is a perspective view for explaining a contact substrate according to the first embodiment; 
     FIG. 6 is a perspective view for explaining mounting of the connector according to the first embodiment; 
     FIG. 7 is a perspective view of the carriage, with the contact substrate omitted from FIG. 6; 
     FIG. 8 is a rear view of the carriage of FIG. 7; 
     FIG. 9 is a perspective view for explaining a contact substrate according to a second embodiment of the present invention; 
     FIG. 10 is a view similar to FIG. 9, with contact omitted from FIG. 9; 
     FIG. 11 is a rear perspective view of the contacts; 
     FIG. 12 is a schematic rear sectional view of the carriage; 
     FIG. 13 is a schematic rear sectional view of another carriage; and 
     FIG. 14 is a schematic view showing a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be explained with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. 
     First Embodiment 
     FIG. 1 is a perspective view showing a first embodiment of the present invention. Two cartridges can be mounted on a carriage  1  which is partitioned into two pockets  2 ,  3 . The pockets  2 ,  3  are provided with positioning grooves  4 ,  5  for the cartridges, side springs  6 ,  7  for preventing lateral deviation of the cartridges, and lock levers  8 ,  9  for pressing and securing the cartridges, respectively, and connectors  10 ,  11  are slightly protruded from corner windows  2   a ,  3   a  of the carriage  1 . 
     As shown in FIGS. 2 and 3 (FIG. 2 is a plan view, and FIG. 3 is a sectional view taken along the line  3 — 3  in FIG.  2 ), each of the connectors  10 ,  11  has a substantially U-shape and a number of metal connection pieces  12  having elasticity are secured to a connector housing  13 . The metal connection pieces  12  are arranged in a staggered fashion so that contact portions  12   a  are staggered with each other, and U-turn portions  12   b  are opposed to each other. A number of ( 34  in the illustrated embodiment) metal connection pieces  12  are disposed within a small housing space. 
     On the other hand, a head cartridge  14  as an example of the cartridge has an ink jet recording head for discharging ink from discharge ports and, as shown in FIG. 4, a wiring board  15  is provided on a rear surface of the head cartridge. Contact pads  16  are located at positions corresponding to the metal connection pieces  12 . Of course, the contact pads  16  are arranged in a staggered fashion. Since the adjacent contact pads (for example,  16   b  and  16   c ) are staggered with each other, adequate contact pad areas can be preserved. As a result, since a contact pitch can be shortened, the increase in the number of contacts can be coped with, without making the connectors  10 ,  11  bulky. 
     Next, the mounting of the connectors  10 ,  11  will be explained with reference to FIGS. 5 and 6. 
     The connectors  10 ,  11  are welded to a contact substrate (electrical part substrate)  17  on which capacitors  18 ,  19 , a position detecting sensor  20  and flexible cable connectors  21 ,  22 ,  23  are mounted. 
     After the contact substrate  17  is installed at a predetermined position on the carriage  1  so that the connectors  10 ,  11  are inserted through openings  1   g ,  1   h  formed in the rear surface of the carriage as shown in FIG. 7, the connectors  10 ,  11  are directly secured to the carriage  1  by screws  24 . In the illustrated embodiment, four screws  24  are used, and each connector is positively secured to the carriage  1  by two screws  24 . Thus, if a reaction force (0.75×34≅2.6 kg in the illustrated embodiment) due to maximum contact pressure is received, the connector housing  13  can be maintained in the predetermined position, thereby ensuring the contact pressure of the metal connection pieces  12 . 
     In the illustrated embodiment, screw escape holes  17   a ,  17   b ,  17   c ,  17   d  are formed in the contact substrate  17 , so that the screws  24  can be threaded into threaded holes  1   a ,  1   b ,  1   c ,  1   d  formed in the carriage through the housings  13 ,  13 ′ without contacting with the contact substrate  17 . 
     With this arrangement, a floating condition between the connectors  10 ,  11  and the contact substrate  17  caused when the connectors  10 ,  11  and the contact substrate  17  are secured to the carriage  1  together (i.e., when the contact substrate is tightened while contacting the screws  24  with the contact substrate) can be prevented, thereby preventing great stress from acting on welded portions  10   a ,  11   a  of the connectors, and, thus, ultimately preventing the floating of connectors and cracking of the substrate. 
     Incidentally, the positioning of the housings  13 ,  13 ′ of the connectors with respect to the carriage  1  is effected by inserting positioning pins (not shown) into positioning holes  1   e ,  1   f  formed in the carriage  1 . 
     In a condition that the four screws  24  are tightened, although the contact substrate  17  is temporarily secured via the welded portions  10   a ,  11   a , it is desirable that, lastly, the contact substrate  17  is secured to the carriage  1  by a screw  25  at a position spaced apart from the welded portion  10   a  as much as possible. 
     In the illustrated embodiment, two head cartridges  14  installed in the pockets  2 ,  3  of the carriage  1  are deviated from each other in a sheet feeding direction in order to prevent the spreading of ink. To this end, two kinds of connectors  10 ,  11  having housings  13 ,  13 ′ of different height are used in order to compensate for such deviation. 
     However, even in a carriage in which only a single head cartridge  14  is installed, it should be understood that the above-mentioned connecting method for connecting between the carriage, connector and contact substrate can be used. 
     Further, as shown in FIG. 3, since each of the elastic metal connection pieces  12  of the connector  10  is displaced around the U-turn portion  12   b  when the contact pressure is applied from a direction shown by the arrow X, the contact portion  12   a  is deviated also in a direction shown by the arrow Y (as shown by the broken line). Due to such lateral deviation, even if foreign matters are adhered to the contact portions  12   a  or the contact pads  16  of the head cartridge  14 , by removing such foreign matters, good contacting condition can be maintained. 
     Second Embodiment 
     FIGS. 9 to  13  show a second embodiment of the present invention. Similar to the first embodiment, two connectors  10  are welded to a contact substrate  30 . However, a positioning spacer  31  is pinched between the substrate and the connectors. The positioning spacer  31  is provided with positioning pins  31   a ,  31   b  with respect to the carriage  1  and connector positioning holes (not shown) so that two connectors  10  can be positioned with respect to the carriage  1  with high accuracy. 
     In the above-mentioned first embodiment, two head cartridges  14  mounted to and installed in the pockets  2 ,  3  of the carriage  1  are deviated from each other in the sheet feeding direction (from a front side to a rear side of the carriage in FIG. 1) in order to prevent the spreading of ink. To this end, two kinds of connectors  10 ,  11  having housings  13 ,  13 ′ of different height are used in order to compensate for such deviation. 
     In the second embodiment, in order to constitute a housing by one kind of parts having the same height, a positioning spacer  31  having an attaching surface with steps of different heights is provided. Since the positioning of two connectors  10  with respect to the carriage  1  is effected by the highly accurate positioning spacer  31 , the attaching accuracy is further improved. Thus, identical parts can be used in a plurality of connectors, thereby preventing error regarding management of connector parts and attachment of connectors. 
     Now, the second embodiment will be fully explained with reference to the accompanying drawings. Incidentally, the construction of the second embodiment is the same as that in the first embodiment, except for special description. 
     FIG. 9 shows the spacer  31  and two connectors  10  mounted on the rear surface of the contact substrate  30  having a front surface on which the capacitors and the positioning detecting sensor or flexible cable connectors are mounted. The spacer  31  is secured to the contact substrate by welding. 
     FIG. 10 shows an arrangement shown in FIG. 9, with the connectors  10  omitted. Further, FIG. 11 shows rear surfaces of the connectors  10  (by which the connectors are mounted on the spacer  31 ). 
     The connectors  10  are positioned with respect to the spacer  31  with high accuracy by inserting positioning pins  10   a ,  10   b ,  10   c ,  10   d  into positioning holes  31   c ,  31   d ,  31   e ,  31   f  of the spacer  31 . In this case, a number of electrical connecting lead pins  10   i  formed on the rear surfaces of the connectors  10  are protruded from the contact substrate through holes  30   a  provided in the spacer  31  and are welded to the contact substrate. 
     The spacer  31  in which the connectors  10  are positioned in this way is secured to the contact substrate, thereby obtaining an arrangement shown in FIG.  9 . 
     Two connectors  10  are exposed in the interior of the carriage through the openings  1   g ,  1   h  formed in the rear surface of the carriage  1 . In this case, the positioning pins  31   a ,  31   b  of the positioning spacer  31  are inserted into the positioning holes  1   e ,  1   f  of the carriage  1 , thereby positioning the spacer  31  with respect to the carriage  1 . 
     Holes of the contact substrate (corresponding to the holes  17   a ,  17   b ,  17   c ,  17   d  in FIG. 6) and screw receiving holes of the carriage (corresponding to the holes  1   a ,  1   b ,  1   c ,  1   d  in FIG. 7 or  8 ) and screw receiving holes  10   e ,  10   f ,  10   g ,  10   h  are secured to each other by the screws  24  in such a manner that the screws  24  are not contacted with holes  31   g ,  31   h ,  31   i ,  31   j  of the spacer  31  (i.e., the contact substrate and the spacer are not substantially secured together by the screws). In this way, similar to the first embodiment, since the contact substrate  30  and the positioning spacer  31  have the screw escape holes and two connectors are directly secured to the carriage  1  by the screws (refer to FIG.  12 ), an external force caused by the screw connection does not act on the contact substrate  30 , with the result that the connectors  10  can be attached to the carriage  1  at correct positions positively. 
     In the first and second embodiments, the screw escape holes may be formed only in the contact substrate  30  and the connectors and the positioning spacer  31  may be secured together to the carriage  1  by the screws (refer to FIG.  13 ). Further, the number of the connectors to be attached to the carriage is not limited two, but may be one, or three or more. 
     Third Embodiment 
     FIG. 14 shows a third embodiment of the present invention. 
     An ink jet recording head  40  of full-line type is installed in such a manner that ink discharge ports  41  are arranged in a direction perpendicular to a conveying or feeding direction for a recording medium  50 . The ink discharge ports  41  of the ink jet recording head  40  of full-line type permit the recording of the entire area in a width-wise direction (perpendicular to the recording medium conveying direction (direction shown by the arrow in FIG.  14 )) of the recording medium  50  without shifting the ink jet recording head in a direction along which the ink discharge ports are arranged. 
     Connectors  42 ,  43  for effecting electrical connection to an external equipment are provided on a rear surface of the ink jet recording head  40 . The ink jet recording head  40  is mounted on a head mounting member  44 , and the connectors  42 ,  43  of the head are connected to connectors  45 ,  46  of the head mounting member. 
     In this embodiment, the connectors  45 ,  46  correspond to the connectors  10 ,  11  in the first or second embodiment, and the head mounting member  44  corresponds to the carriage  1 . 
     In the first or second embodiment, while the recording apparatus of serial type was explained, the present invention can be well applied to a recording apparatus of so-called full-line type. Particularly, in the recording head of full-line type in which the number of ink discharge ports (as recording unit) is greater than that in the recording head of serial type, the number of electrical contacts is naturally increased, and, thus, an urging force generated by the metal contacts becomes greater than that in the recording head of serial type. Therefore, the present invention which can suppress the influence of the external force upon the contact substrate is more effective for the full-line type. 
     The ink jet recording head according to the present invention may be an ink jet recording head which has an electrothermal converting element (not shown) and discharges ink from the discharge port utilizing thermal energy generated by the electrothermal converting element. 
     As mentioned above, according to the above-mentioned embodiments, when the contact substrate having the connector comprised of a number of elastic metal connection pieces is secured to the carriage, damage of the welded portions of the connector and cracking of the print substrate can be prevented. 
     Further, since the connector is directly secured to the carriage by the attaching members, even if the reaction force of the elastic metal connection pieces acts on the connector, the connector housing is not shifted from the predetermined position. Thus, a good contacting condition of the elastic metal connection pieces can be maintained. 
     In addition, when the contact substrate having a plurality of connectors each comprised of a number of elastic metal connection pieces is secured to the carriage, by positioning the carriage and the connectors with the interposition of the spacer, the positioning accuracy of the carriage and the connectors can be improved greatly, as well as the above-mentioned effect. 
     Further, when the plurality of head cartridges are deviated from each other in the sheet feeding direction, by absorbing such deviation by means of the spacer, since the identical connectors can be used, management of parts can be facilitated and cost can be reduced.