Ink jet recording head and ink jet recording apparatus

Abstract: In an ink jet recording device having an ink tank integrated type jet recording head (10) and a carriage (20) for mounting the head thereon, good electrical connection is obtained by constituting so that the electrical pad of the connecting terminal (10a) of the recording head (10) and the electrical pad of the connecting terminal (20a) of the carriage (20) are connected to each other while rubbing them one to one. Further, also by specifying the arrangement position of the positioning member, more accurate electrical conduction is effected and also breaking of the positioning member is prevented, thereby providing an ink jet recording device having high reliability in both aspects of recording and durability.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to an ink jet recording apparatus to be employed for copying device, facsimile, word processor, video output printer, output printer of computer, etc., particularly to a constitution for mounting a recording head equipped integrally with an ink tank for containing ink freely detachably onto the carriage as the recording head mounting means. Related Background Art Of the ink jet recording apparatus, there has been known one using an ink jet recording head such as disposable head comprising internally an integrated combination of an ink tank for housing ink which is a recording medium and a recording head element having the function of discharging ink (hereinafter called recording head or ink jet recording head cartridge). Examples of the mounting methods of such recording heads are described in US-A-4736213 (Platt et al), USP 4,599,625 (Terasawa et al), USP 4,630,078(Watanabe), USP 4,633,274 (Matsuda), USP 4,635,080 (Watanabe), USP 4,712,172 (Kiyohara et al), USP 4,727,384 (Tsuda), US-A-4872026 (Rasmussen et al), etc. In mounting such recording head onto the carriage on the main body side of the recording device, since recording must be performed by attaching ink accurately to the adequate position on the recording paper, and the connecting terminal for transmitting recording signals adequately, it has been required to fix and mount the recording head at adequate position. To classify broadly the mounting methods of recording heads, there may be included the methods in which the ink cartridge is mounted from above or behind of the carriage in parallel or by simple rotation. As an example which performs mounting simply, there is such constitution as shown in Fig. 1A. 101 is a recording head of the type integrated with an ink tank, having a connecting terminal 101a having a plurality of electrical pads 111 and a discharge port surface of the ink recording head element 101c provided at the bottom. The carriage 102 is provided with a connecting terminal 102a for transmitting recording signals to the recording head. Here, 102a is constituted of a plurality of electrical pads 112. 104 is a guide shaft for guiding movement of the carriage 102. Thus, when the recording head is mounted from above the carriage, attachment and detachment can be done very easily, but since the connecting terminals 101a and 102a are not rubbed with each other during mounting and therefore, it there was a coating or a foreign matter due to ink contamination interposed between the connecting terminals, defective connection sometimes occurred. Also, unused recording head may sometimes take a constitution in which a very thin insulating protective film 121 is provided for protection of connecting terminals. Then, in the case of such mounting method, there is no action of ensuring connection by scraping off the protective film. Therefore, this example could never be said as the optimum example as the connecting method of signal terminals. Also, in commencing use by mounting unused recording head, it is necessary to form immediately the state where ink can be well discharge by means of a discharge restoration means, etc. Accordingly, the present inventors have thought of attaching and detaching the recording head at the home position which becomes the waiting position of the recording head, and protecting the discharged port preferably on completion of mounting of the recording head. Fig. 2A, as an example based on the above thought, mounts a recording head from behind the carriage. Similarly as in Fig. 1, 101 is the recording head and 102 is the carriage. Here, 103 is a discharge restoration device equipped with a cap for protecting the discharge port of the recording head and preventing ink fixing. The constitution is such that, by performing mounting of the recording head by inserting the recording head 101 from behind the carriage 102 in the direction of the arrowhead, the recording head 101 is capped at the fixed position, and the connecting terminals 101a and 102a are correctly connected. However, according to such method, the connecting terminals will be respectively rubbed during mounting successively. Particularly, the electrode pad 101 of the connecting terminal of the recording head located on the discharging port side will be rubbed with all the electrode pads of the carriage 102. Therefore, a part of all of the terminals will be considerably damaged, whereby it has been found that electrical signals cannot be transmitted to cause defective discharging. Accordingly, the present inventors have further thought of a method of mounting by rotation of the recording head 101 as shown in Fig. 2B, but with such constitution, mounting must be done with the discharge port surface 101b which becomes the front surface of the recording head 101, particularly the upper part of 101b being forwarded greatly before the constant position after mounting. Then, a great space is required in front of the carriage. However, when good ink discharging is considered, since the interval between the recording head and the recording paper is designed to be 3.0 mm or less, and therefore it has been found to be difficult to take such constitution. Also, even if mounting may be effected at the home position, because great mutual interference with the cap cannot be avoided, such inconvenience as deformation of cap, etc. has been found to occur. According to one aspect of the present invention, there is provided an ink jet recording apparatus comprising: a carriage for mounting an ink jet cartridge, said carriage having a first electrical contact portion; and an ink jet cartridge for mounting on said carriage, said cartridge comprising: a recording head having a discharge port for discharging ink, a second electrical contact portion and a centre of rotation for enabling the recording head to be rotated into its mounting position on the carriage, characterised in that said centre of rotation is provided at a position closer to said ink discharge port than said second electrical contact portion and said ink jet cartridge is adapted to be mounted to said carriage by rotation about said centre of rotation thereby causing said first and second contact portions to rub together with substantial relative lateral movement and an electrical connection to be made between said first and second electrical contact portions. The present invention also provides an ink cartridge for mounting on a carriage of an ink jet recording apparatus, said cartridge comprising: a recording head having a discharge port for discharging ink, an electrical contact portion for contacting an electrical contact portion of said carriage and a centre of rotation for enabling said recording head to be rotated into its mounting position on the carriage, characterised in that said centre of rotation is provided at a position closer to said ink discharge port than the electrical contact portion of said recording head and said ink jet cartridge is adapted to be mounted to said carriage by rotation about said centre of rotation thereby causing said recording head and carriage contact portions to rub together with substantial relative lateral movement and electrical connection to be made between said recording head and cartridge contact portions. The present invention also provides a method of mounting to a carriage of an ink jet recording apparatus having a first electrical contact portion an ink jet cartridge comprising a recording head having a discharge port for discharging ink and having a second electrical contact portion, comprising: mounting said cartridge to said carriage by rotating said ink jet cartridge about a centre of rotation thereof positioned closer to said ink discharge port than said second contact portion to cause said first and said second electrical contact portions to be brought into contact and rubbed together with substantial relative lateral movement and to establish an electrical connection between said first and said second electrical contact portions. An embodiment of the present invention provides an ink jet recording apparatus comprising a recording head capable of effecting electrical connection in connecting the connecting terminals without damaging terminals and which can also scrape off the protective film provided on the terminal surface by mutual rubbing of the terminals with each other, and capable of positioning surely the recording head simultaneously with mounting completion of the recording head and a member for mounting of recording head and a recording head mounting method and an ink jet recording device. An embodiment of the present invention provides an ink jet recording apparatus comprising a tank integrated type recording head which can be accurately positioned as the ink jet recording head onto a carriage of the ink jet recording apparatus, which carriage can more surely hold said recording head and wherein the recording head can be accurately held under the desired state relative to within the main body of the apparatus and the carriage. An ink jet recording apparatus embodying the present invention can elongate the life of the positioning portion of said head itself which is detachable and of the cap within the main body. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic side view showing a prior art example of the mounting actuation of a recording head. Fig. 2A is a schematic side view showing an example of the mounting actuation of a recording head. Fig. 2B is a schematic side view showing an example of the mounting actuation of a recording head. Fig. 3 is a schematic perspective view showing the ink jet recording device according to the first embodiment of the present invention. Fig. 4 is a schematic perspective view showing the constitution of the recording head according to the first embodiment of the present invention. Figs. 5A and 5B are a schematic perspective view and a top view showing the constitution of the carriage according to the first embodiment of the present invention. Figs. 6A to 6D are schematic illustrations showing the mounting actuation of the recording head according to the first embodiment of the present invention. Figs. 7A to 7E are schematic illustrations showing the manner of connection of the recording head and the connecting terminals of the carriage according to the first embodiment of the present invention. Figs. 8A and 8B are schematic partially enlarged views showing the manner of connection of the connecting pads in Figs. 5A to 5E. Fig. 9 is a schematic perspective view showing the ink jet recording device according to the second embodiment of the present invention. Figs. 10A and 10B are a schematic perspective view and a sectional view showing the constitution of the recording head according to the second embodiment of the present invention. Figs. 11A and 11B are a schematic perspective view and a top view showing the constitution of the second embodiment of the present invention. Figs. 12A to 12D are schematic illustrations showing the mounting actuation of the recording head according to the second embodiment of the present invention. Figs. 13A to 13E are schematic illustrations showing the manner of the connecting terminal according to the present invention. Figs. 14A and 14B are schematic partially enlarged views showing the manner of connection of the connecting pads in Figs. 13A to 13E. The present invention is described below by referring to a plurality of embodiments, but the present invention is not limited by these but includes many modified embodiments falling within the scope of the appended claims. An ink jet recording apparatus embodying the present invention can perform positioning of the recording head and the carriage with good precision, and with such constitution, accurate positioning of the ink discharge port, and accurate positioning capable of joining pads as unit elements of electrical connecting terminals while rubbing with each other at one to one can be done. In the following, the respective embodiments are to be described in detail. [First Embodiment] This embodiment is an ink jet recording head having a discharge port for discharging ink and an energy generation means for generating energy for discharging ink, which is detachable relative to the mounting means for mounting the recording head onto the recording head of ink jet recording means, characterized in that the recording head has a surface having the discharge port provided thereon, an electrical connecting terminal provided on a surface forming a specific angle with respect to the surface and a rotation center portion in attachment and detachment relative to the mounting means of the recording head, the center axis of the rotation center portion is substantially parallel to the surface where the discharge port is provided and the surface where the connecting terminal is provided, with its position being made on the side opposed to the connecting terminal with respect to the surface where the discharge port is provided and outside the range where the discharge port is provided, and on the discharge port side relative to the connecting terminal near the surface side where the discharge port is provided. Also, this embodiment provides an ink jet recording device, comprising an ink jet recording head having a discharge port for discharging ink and energy generation means for generating energy for discharging ink, wherein the recording head has a surface having the discharge port provided thereon, an electrical connecting terminal provided on a surface forming a specific angle with respect to the surface and a rotation center portion in attachment and detachment relative to the mounting means of the recording head, the center axis of the rotation center portion is substantially parallel to the surface where the discharge port is provided and the surface where the connecting terminal is provided, with its position being made on the side opposed to the connecting terminal with respect to the surface where the discharge port is provided and outside the range where the discharge port is provided, and on the discharge port side relative to the connecting terminal near the surface side where the discharge port is provided and a mounting means having a site to be engaged to the rotation center for mounting the recording head. Further, this embodiment is a method for mounting a recording head having a discharge port for discharging ink, an energy generation means for generating the energy for discharge of the ink through the discharge port and an electrical connecting terminal provided on a surface forming a specific angle with respect to the surface where the discharge port is provided, wherein the recording head is mounted by engaging the rotation center portion having a center axis in parallel to both the surface where the discharge port is provided and the surface where the connecting terminal is provided and located on the side opposed to the connecting terminal with respect to the surface where the discharge port is provided, outside of the range where the discharge port is provided and on the discharge port side relative to the connecting terminal near the surface side where the discharge port is provided, to the site corresponding to the mounting means with the rotation center portion as the center. Referring now to Figs. 3 through Fig. 8B, this embodiment is described specifically and in detail. Fig. 3 is a schematic perspective view of appearance showing the principal part of the recording device. Fig. 4 is a schematic perspective view of the recording head according to the embodiment of the present invention as viewed from the bottom side, and Fig. 5A is a schematic perspective view according to this embodiment, and Fig. 5B is a schematic plan view of the carriage of this embodiment as viewed from above. First, in Fig. 3 the carriage 20 as the mounting means having the recording head 10 mounted thereon moves along the paper delivery roller 60 as guided by the guide shaft 40. The constitution is made such that the recording head 10 discharges ink toward the surface of the recording paper P as the recording medium, and forms an image with the attached ink droplets, thereby performing recording. 30 is the discharge restoration means located at the home position of the carriage 20. The discharge restoration means is constituted of a cap 31 comprising an elastic material such as rubber, etc. provided for protecting the discharge port by covering over the discharge port and also preventing fixing of ink by prevention of drying of the discharge port vicinity including the discharge port, and a suction pump 33 communicated to the cap 31 through an elastic tube 32. By sucking ink and/or air through the discharge port by reducing the pressure internally of the cap 31 with the pump 33, the discharging state of ink can be made good. The carriage 20 is located at the home position as the non-recording position except when the recording head 10 performs recording, so that the discharge port may be protected there with the cap 31. And, the constitution is made so that attachment and detachment of the recording head 10 may be performed necessarily at the home position. This can be done by controlling electrically the motor (not shown) for driving the carriage. Next, by referring to Fig. 4, the constitution of the recording head 10 is described. In these Figures, the recording head 10 of the ink tank integration type is equipped with a recording head element 10C provided with an electrothermal transducer not shown as the energy generation means for generating thermal energy as the energy to be utilized for discharging of ink. For such recording head element, otherwise a piezoelectric element, etc. can be also employed as the energy generation means. However, the constitution by use of the electrothermal transducer as mentioned above having the advantages of simple constitution, lowered production cost and possibility of high densification may be preferably utilized. 10a is a connecting terminal for transmitting the recording signal (electrical signal), 10b a guide pin which becomes the rotation center of the recording head 1 during attachment and detachment relative to the carriage 20 by fitting to the carriage 20 as described below. The recording head element 10c is provided with a plurality of ink discharge ports 10d on the front surface. The connecting terminal 10a is provided with a concavity 10f which is a portion recessed by about 1 to 2 mm toward inside with longitudinal length X = 35 mm and lateral length Y = 10 mm for preventing contamination with ink, etc. and deformation, etc. of the connecting terminal 10a by touching with hands during handling. Behind the recording head is provided a fixing hook 10g (see Fig. 6A) for fixing the recording head through engagement with the nail portion of the carriage 20. Referring now to Figs. 5A and 5B, the constitution of the carriage 20 is described. In these Figures, 20a is the connecting terminal bonded to the connecting terminal 10a of the recording head 10, 20b the fitting portion fitted (engaged) to the guide pin 10b of the recording head 10, 20c the elastic member for giving an adequate pressure contact force (20 to 50 g per one terminal) during bonding of the connecting terminals 10a and 20a, for which chloroprene rubber, urethane rubber, moltprene rubber, etc. may be used as preferable material for having optimum modulus of elasticity. 22 is a plate spring provided to taking balance with the pressure forces of connecting terminals 10a and 20a, and has the hop-up function during dismantling of the head as described below. A projection 23 is engaged with the fixing hook 10g of the recording head 10 to fix and hold the recording head 10. 50 is a flexible cable for transmitting electrical signals from the recording control section not shown to the connecting terminal 20a of the carriage. Here, although the description of the connecting terminal 20a is different between Figs. 5A and 5B, this is done for simplification of the drawings, and the specific constitutions should be understood from the following description. The mounting method of the recording head in the constitution as described above is described in detail by referring to Figs. 6A to 6D. Fig. 6A shows the state of mounting initiation state, Fig. 6B the first state in the course of mounting, Fig. 6C the second state in the course of mounting and the Fig. 6D the state on completion of mounting. First, as shown in Fig. 6A, when the recording head 10 is placed on the carriage 20, the guide pin 10b of the recording head 10 and the carriage 10 at the bottom of the head 10 are guided by the guide surface 20h and the tip end 20t of the lock lever 20i, and moves in the direction A in the Figure by the weight of the recording head 1. Next, as shown in Fig. 6B, when the guide pin 10b is fitted into the fitting portion 20b, the rear end portion of the recording head 10 comes off from the lock lever 20i, to rotate the guide pin 10b in the direction C with the guide pin 10b as the center, whereby the fixing hook 10g comes against the lock lever as shown in Fig. 6C. Next, when the rear end of the recording head 10 is compulsorily pushed down in direction D, the discharge port surface from the state as shown in Fig. 6C contacts little by little from its upper portion the elastic portion of the cap 31. Then, the connecting terminals 10a and 20a contact successively from the discharge outlet side, until finally the fixing hook l0g is hooked by the nail portion 23 of the lock lever 20i to become the state held by fixing as shown in Fig. 6D, whereby the connecting terminals 10a and 20a are correctly connected electrically and mechanically. In the constitution capable of performing the actuation as described above, since the guide pin 10b, namely the rotation center of the recording head 10 is provided within the range AR upwardly of the position corresponding to the cap and in front of the connecting terminal, the front surface (namely discharge port) and the cap 31 of the recording head element 10c, and the connecting terminals 10a and 20a are adequately contacted or connected with each other without interference with other portions. Further, by slight rubbing mutually between the connecting terminals during mounting of the recording head 10, foreign matters existing on the terminal surface can be also shaven off or scraped off to give the action of effecting surely electrical connection. This manner is described in more detail by referring to Figs. 7A to 7E and Figs. 8A and 8B. Figs. 7A through 7E show the manner in which the connecting terminals are bonded to each other. Figs. 8A and 8B are schematic illustrations partially enlarged of one of a plurality of electrode pads of connecting terminal, showing the states at the beginning of contact and on completion of connection. The plural number of electrode pads 13 of the connecting terminal 10a of the recording head 10 of this embodiment are made of lead frame of metal, etc., with the contact points being made flat. The plural number of electrode pads 24 of the connecting terminal 20a of the carriage 20 are worked into semispherical projected shapes by application of plating to the terminal on the flexible cable 50. Corresponding to the mounting actuation of the recording head, the electrode pads from the discharge port side will contact from the state in Fig. 7A as shown in Fig. 7B, and successively as shown in Fig. 7C. In transferring from Figs. 7B to 7E, the pads are rubbed mutually one to one to maintain good electrical contact. The pressure contact force at the contact point of the pad is controlled through deformation of the elastic member 20c, whereby superfluous contact force can be absorbed to give adequate pressure contact force. When mounting of the recording head is completed, as shown in Fig. 7E, the position of the connecting terminal 20a of the carriage is positioned lower than the position in Fig. 5A, whereby the pressure contact force is applied upwardly with the elastic member 20c. Such pressure contact force is balanced with the forces of the projection 23 and the fitting portion 20b of the carriage. Further, connection of the terminal is described in detail by referring to Figs. 8A and 8B. In Figs. 8A and 8B, I shows the contact position of the electrode pad 12 at the beginning of contact, and J the contact position of the electrode pads 13, 24 under the final state. Through the slippage k between the contact points, even when foreign matters may be adhered on the contact point terminal surface, they can be scraped off to effect sure electrical connection. For connection as describe above (k > 0) to be effected, the constitution is required to be made such that the rotation center as the standard for rotation should be positioned with a predetermined distance in the direction of the normal line 13-2 of the contact portion of the electrode pad 13 of the recording head from the tangential line 13-1 of the contact portion, and also the electrical pad 24 of the carriage 20 should be dislocated (m > 0) when the head 10 is mounted. Next, the method for dismantling the recording head 10 is to be described. First, when the lock lever 20i is moved by pressing in the direction EJ in Fig. 6B as described above, the fixing hook 10g is disengaged from the nail 23 to release fixing of the recording head. Then, by the plate spring 22 provided for taking balance with the connecting terminals 10a and 20a, the rear portion of the recording head is hopped up through elastic force, and can be readily taken out. Further, in the above-described embodiment of the present invention, the ink discharge port 10d, the electrical connecting terminal 10f are all provided on substantially one straight line in the recording head element 10c so as to hold readily the positional relationships of the respective elements with high precision. Also, in the present embodiment, further the above elements are provided on one end side where the recording head is located, and further the cap is located on the above straight line in the home position. According to this constitution, the positioning member for carriage and electrical connecting terminals can be arranged on one side of the recording head and the carriage, whereby an extremely advantageous constitution in aspect of practical armoring such as withdrawing of flexible cable, etc. is given, and also unsure capping due to positional slippage can be prevented to make the probability of breaking of the recording head and the cap accompanied with mounting actuation of the recording head very lower. As described above, according to the mounting method of the first embodiment of the present invention, there is no breaking by way of rubbing of connecting terminals than is necessary and the recording head will receive no bad influence from outside, and also, even if foreign matters may be attached on the terminal surface of the recording head, they can be removed to effect mounting of the recording head onto the correct position of the carriage with a force enough to obtain electrical connection. Also, attachment and detachment of the recording can be surely done while performing positioning with high precision. [Second embodiment] Next, the second embodiment according to the present invention is to be described. Many points of the constitution of this embodiment are the same as in the first embodiment as described above. The different point is that a positioning means for performing positioning with still better precision is provided. More specifically, this embodiment is an ink jet recording head having a discharge port for discharging ink and an energy generation means for generating energy for discharging ink, which is detachable relative to the mounting means for mounting the recording head onto the recording head of an ink jet recording means, characterized in that the recording head has a surface having the discharge port provided thereon, an electrical connecting terminal provided on a surface forming a specific angle with respect to the surface and a rotation center portion in attachment and detachment relative to the mounting means of the recording head, the center axis of the rotation center portion is substantially parallel to the surface where the discharge port is provided and the surface where the connecting terminal is provided, with its position being made on the side opposed to the connecting terminal with respect to the surface where the discharge port is provided and outside the range where the discharge port is provided, and on the discharge port side relative to the connecting terminal near the surface side where the discharge port is provided, and further has a positioning member provided between the discharge port and the connecting terminal. Further, it is an ink jet recording device, comprising an ink jet recording head having a discharge port for discharging ink and an energy generation means for generating energy for discharging ink, wherein the recording head has a surface having the discharge port provided thereon, an electrical connecting terminal provided on a surface forming a specific angle with respect to the surface and a rotation center portion in attachment and detachment relative to the mounting means of the recording head, the center axis of the rotation center portion is substantially parallel to the surface where the discharge port is provided and the surface where the connecting terminal is provided, with its position being made on the side opposed to the connecting terminal with respect to the surface where the discharge port is provided and outside the range where the discharge port is provided, and on the discharge port side relative to the connecting terminal near the surface side where the discharge port is provided, further having a positioning means provided between the discharge port and the connecting terminal, and a mounting means having a member engaged with the positioning member for mounting the recording head. Referring now to the drawings of Figs. 9 through 14B, one embodiment of the present invention is to be described specifically and in detail. Fig. 9 is a schematic perspective view of appearance showing the principal part of the recording device. Fig. 10A is a schematic perspective view of the recording to the embodiment of the present invention as viewed from the bottom side, Fig. 10B is a schematic plan view of the recording head according to this embodiment, Fig. 11A is a schematic perspective view of the carriage according to this embodiment, and Fig. 11B is a schematic plan view of this embodiments as viewed from above. First, in Fig. 9, the carriage 20 as the mounting means having the recording head 10 mounted thereon moves along the paper delivery roller 60 as guided by the guide shaft 40. Recording head 10 discharges ink toward the surface of the recording paper P as the recording medium, thereby forming an image with the attached ink droplets to effect recording. 30 is the discharge restoration means located at the home position of the carriage 20. The discharge restoration means is constituted of a cap 31 comprising an elastic material such as rubber, etc. provided for protecting the discharge port by covering over the discharge port and also preventing ink from depositing by prevention of drying of the discharge port vicinity including the discharge port, and a suction pump 33 communicated to the cap 31 through an elastic tube 32. By sucking ink and/or air through the discharge port by reducing the internal pressure of the cap 31 with the pump 33, the discharging state of ink can be made good. The carriage 20 is located at the home position as the non-recording position except when the recording head 10 performs recording, so that the discharge port may be protected there with the cap 31. And, the constitution is made so taht attachment and detachment of the recording head 10 may be performed necessarily at the home position. The above-mentioned constitution is the same as in the first embodiment. Next, by referring to Figs. 10A and 10B, the constitution of the recording head 10 is described. In these Figures, the recording head 10 of the ink tank integration type is equipped with a recording head element 10c provided with an electrothermal transducer not shown as the energy generation means for generating thermal energy as the energy to be utilized for discharging of ink. As the energy generation means to be employed for such recording head element, otherwise a piezoelectric element, etc. can be also employed. However, the constitution by use of the electrothermal transducer as mentioned above having the advantages of simple constitution, lowered production cost and possibility of high densification may be preferably utilized. 10a is a connecting terminal for transmitting the recording signal (electrical signal), 10b a guide pin which becomes the rotation center of the recording head 1 during attachment and detachment relative to the carriage by fitting to the carriage 20 as described below. The recording head element 10c is provided with a plurality of ink discharge ports 10d on the front surface. The connecting terminal 10a is provided with a concavity 10f which is a portion recessed by about 1 to 2 mm toward inside with longitudinal length X = 35 mm and lateral length Y = 10 mm for preventing contamination with ink, etc. and deformation, etc. of the connecting termianl 10a by touching with hands during handling. Behind the recording head is provided a fixing hook 10g (see Fig. 6A) for fixing the recording head through engagement with the nail portion of the carriage 20. And as the characteristic point of this embodiment, a rib 11 as the positioning member is provided on substantially the straight line connecting the ink discharge port 10d and the connecting terminal 10b. The rib 11 performs positioning through engagement of the positioning member of the carriage 20 as described later. Referring now to Figs. 11A and 11B, the constitution of the carriage 20 is described. In these Figures, 20a is the connecting terminal bonded to the connecting terminal 10a on the carriage side of the recording head 10, 20b the fitting portion fitted to the guide pin 10b of the recording head 10, 20c the connecting terminal 10a, 20a the elastic member for giving an adequate pressure contact force (20 to 50 g per one terminal) during bonding of the 20a, for which chloroprene rubber, urethane rubber, moltprene rubber, etc. may be used as preferable material for having optimum modulus of elasticity. 21 is a positioning member formed at the concavity for effecting positioning through engagement with the positioning rib 11 of the recording head 10. The positioning member on the inserted side is tapered as shown in Fig. 11B, 22 is a plate spring provided to take balance with the pressure forces of connecting terminals 10a, 20a, and has the hop-up function during dismantling of the head as described below. 23 is engaged with the fixing hook 10g of the recording head 10 to fix and hold the recording head 10. 50 is a flexible cable for transmitting electrical signals from the recording control section not shown to the connecting terminal 20a of the carriage. The mounting method of the recording head in the constitution as described above is described in detail by referring to Figs. 12A, 12B, 12C and 12D. Fig. 12A shows the state of mounting initiation state, Fig. 12B the first state in the course of mounting, Fig. 12C the second state in the course of mounting and the Fig. 12D the state on completion of mounting. First, as shown in Fig. 12A, when the recording head 10 is placed on the carriage 20, the guide pin 10b of the recording head and the carriage 10 at the bottom of the recording head are guided by the guide surface 20h and the tip end 20t of the lock lever 20i, and moves readily in the direction A in the Figure by the weight of the recording head 1. Next, as shown in Fig. 12B, when the guide pin 10b is fitted into the fitting portion 20b, the rear end portion of the recording head 10 comes off from the lock lever 20i, to rotate the guide pin 10b in the direction C with the guide pin 10b as the center, whereby the fixing hook 10g comes against the lock lever as shown in Fig. 12C. At this time, for positioning of the recording head 10, the side face 11a of the rib 11 (Fig. 10B) begins to be fitted into the inside face 21a (Fig. 11B) of the positioning member 21 of the carriage 20 to effect positioning in the direction x in Fig. 11B. Next, when the rear end of the recording head 10 is compulsorily pushed up in the direction D in Fig. 12C, the discharge port surface from the state as shown in Fig. 12C contacts little by little from its upper portion the elastic portion of the cap 31. Then, the connecting terminals contact successively from the discharge port side, then the pads of connecting terminals 10a, 20a successively from the discharge port side, until finally the fixing hook 10g is hooked by the nail portion 23 of the lock lever 20i to become the state held by fixing as shown in Fig. 12D, whereby the connecting terminals 10a and 20a are correctly connected electrically and mechanically. At this time, the discharge port is also surely capped. At this time, the front surface 11b of the positioning rib 11 of the recording head 10 and the inner rear surface 21b of the positioning member 21 of the carriage 20 come against each other, whereby the positioning in the direction y in Fig. 11B is effected (see Figs. 10B, 11B). In the constitution capable of performing the actuation as described above, since the guide pin 10b, namely the rotation center of the recording head 10 is provided within the range PC in Fig. 12D upwardly of the position corresponding to the cap and in front of the position PT of the connecting terminal, the front surface (namely discharge port) and the cap 31 of the recording head element 10c, and the connecting terminals 10a and 20a are adequately contacted or connected with each other without interference with other portions. Further, by slight rubbing mutually between the connecting terminals during mounting of the recording head 10, foreign matters existing on the terminal surface can be also shaven off or scraped off to give the action of effecting surely electrical connection. This manner is described in more detail by referring to Figs. 13A to 13E, 14A and 14B. Fig. 13A through 13E show the manner in which the connecting terminals are bonded to each other. Figs. 14A and 14B are schematic illustrations partially enlarged of one of a plurality of electrode pads as unit elements of connecting terminal, showing the states at the beginning of contact and on completion of connection. The plural number of electrode pads 13 of the connecting terminal 10a of the recording head 10 of this embodiment are made of lead frame of metal, etc., with the contact points being made flat. The plural number of electrode pads 24 of the connecting terminal 20a of the carriage 20 are worked into semispherical projected shapes by application of plating to the terminal on the flexible cable 50. Corresponding to the mounting actuation of the recording head, first the electrode pads from the discharge port side will contact from the state in Fig. 13A as shown in Fig. 13B, and successively as shown in Fig. 13C. In transferring from Figs. 13B to 13E, the pads are rubbed mutually one to one to maintain good electrical contact. The pressure contact force at the contact point of the pad is controlled through deformation of the elastic member 20c, whereby superfluous contact force can be absorbed to give adequate pressure contact force. When mounting of the recording head is completed, as shown in Fig. 13E, the position of the connecting terminal 20a of the carriage is positioned lower than the position in Fig. 13A, whereby the pressure contact force is applied upwardly with the elastic member 20c. Such pressure contact force is balanced with the forces of the nail 23 and the fitting portion 20b of the carriage. Further, connection of the terminal is described in detail by referring to Figs. 14A and 14B. In Figs. 14A and 14B, I shows the contact position of the electrode pad 12 at the beginning of contact, and J the contact position of the electrode pads 13, 24 under the final state. Through the slippage k between the contact points, even when foreign matters may be adhered on the contact point terminal surface, they can be scraped off to effect sure electrical connection. For connection as described above (k > 0) to be effected, the constitution is required to be made such that the rotation center as the standard for rotation should be positioned with a predetermined distance in the direction of the normal line 13-2 of the contact portion of the electrode pad 13 of the recording head from the tangential line 13-1 of the contact portion, and also the electrical pad 24 of the carriage 20 should be dislocated (m > 0) when the head 10 is mounted. Next, the method for dismantling the recording head 10 is to be described. First, when the lock lever 20i is moved by pressing in the direction EJ in Fig. 12D, the fixing hook 10g is disengaged from the nail 23 to release fixing of the recording head 10. Then, by the plate spring 22 provided for taking balance with the connecting terminals 10a, 20a, the rear portion of the recording head is hopped up through elastic force, and can be readily taken out. Further, in the above-described embodiment of the present invention, the ink discharge port 10d, the positioning rib 11, the electrical connecting terminal 10f are all provided so as to be overlapped at least a part of the respective elements on substantially one straight line in the recording head element 10c, the positional relationships of the three elements can be held with high precision. Also, in the present embodiment, further the above three elements are provided on one end side where the recording head is located, and further the cap is located on the above straight line in the home position. According to this constitution, the positioning member for carriage and electrical connecting terminals can be arranged on one side of the recording head and the carriage, whereby an extremely advantageous constitution in aspect of practical armoring such as withdrawing of flexible cable, etc. is given, and also unsure capping due to positional slippage can be prevented to make the probability of breaking of the recording head and the cap accompanied with mounting actuation of the recording head very lower. As described above, according to the mounting method of the first embodiment of the present invention, there is no breaking by way of rubbing of connecting terminals than is necessary and the recording head will receive no bad influence from outside, and the recording head can be positioned to the correct position of the carriage. Further, the ink discharge port of the head, the positioning member and the electrical connecting member can be arranged in this order on substantially straight line, whereby attachment and detachment of the recording head can be done simply and surely, while positioning the position of the ink discharge port and the position of the electrical connecting terminal relative to the carriage with high precision. Thus, by one actuation of mounting of the recording head, at least the three operations of positioning of head, electrical connection, capping can be completed. Also, in the above second embodiment, the cap, the positioning rib and the connecting terminal are on substantially straight line. That is, they are not completely coincident on one straight line, but a part of the respective elements are deviated from the straight line, but of course they can be made coincident with each other.

Claims: An ink jet recording apparatus comprising: a carriage (20) for mounting an ink jet cartridge (10), said carriage having a first electrical contact portion (20A); and an ink jet cartridge for mounting on said carriage (20), said cartridge comprising: a recording head (10C) having a discharge port (10D) for discharging ink, a second electrical contact portion (10A) and a centre of rotation (10B) for enabling the recording head to be rotated into its mounting position on the carriage, characterised in that said centre of rotation is provided at a position closer to said ink discharge port (10D) than said second electrical contact portion (10A) and said ink jet cartridge (10) is adapted to be mounted to said carriage (20) by rotation about said centre of rotation (10B) thereby causing said first and second contact portions to rub together with substantial relative lateral movement and an electrical connection to be made between said first and second electrical contact portions (10A, 20A). An ink jet recording apparatus in accordance with claim 1, wherein said second electrical contact portion (10A) and said ink discharge port (10D) are provided on different surfaces of said ink jet cartridge (10). An ink jet recording apparatus in accordance with claim 2, wherein said ink discharge port (10D) is provided on the front surface of said ink jet cartridge (10) and said second electrical contact portion (10A) is provided on the bottom surface of said ink jet cartridge (10). An ink jet recording apparatus in accordance with claim 2, wherein said recording head (10C) has a discharge port (10D) at a position protected from a first surface, and said second electrical contact portion (10A) is provided in a concavity in a surface perpendicular to said first surface. An ink jet recording apparatus in accordance with any preceding claim, wherein said recording head (10C) is adapted to record by discharging ink utilizing heat energy. An ink jet recording apparatus in accordance with any preceding claim wherein said ink jet cartridge (10) further comprises an ink tank for containing ink to be supplied to said recording head (10C). An ink jet recording apparatus in accordance with any preceding claim, wherein said ink jet cartridge (10) has a guide member (10B) for guiding said ink jet cartridge (10) during mounting of said ink jet cartridge (10) onto said carriage (20). An ink jet recording apparatus in accordance with claim 7, wherein said guide member (10B) comprises guide pins provided at said centre of rotation and said carriage (20) further comprises guide portions (20B) for accepting said guide pins. An ink jet recording apparatus in accordance with any preceding claim, wherein said ink jet cartridge (10) further comprises a positioning rib (11) and said carriage (20) has a positioning member (21) for accepting said positioning rib (11). An ink jet recording apparatus in accordance with any preceding claim, wherein said ink jet cartridge (10) has a projection for aiding positioning to receive the urging force for fixing said ink jet cartridge (10) on said carriage (20). An ink jet recording apparatus in accordance with any preceding claim wherein said carriage further comprises retaining means (23) for retaining said ink jet cartridge (10) in a mounted position when said ink jet cartridge (10) is mounted on said carriage (20). An ink jet recording apparatus in accordance with any preceding claim wherein said first electrical contact portion (20A) is elastically supported by an elastic member (20C) adapted to be deformed when said ink jet cartridge (10) is mounted to said carriage (20) and rotated about said centre of rotation (10B) to enable said first and second electrical contact portions (10A, 20A) to rub together with substantial relative lateral movement. An ink jet recording apparatus in accordance with any preceding claim, wherein said carriage (20) further comprises a plate spring (22) adapted to balance the pressures between the connection terminals of said first and second electrical contact portions (20A, 10A). An ink jet recording apparatus in accordance with any preceding claim, wherein the connection terminals of said first electrical contact portion (20A) comprise hemispherical projections and the connection terminals of said second electrical contact portion (10A) are flat. An ink cartridge for mounting on a carriage (20) of an ink jet recording apparatus (10), said cartridge comprising: a recording head (10C) having a discharge port (10D) for discharging ink, an electrical contact portion (10A) for contacting an electrical contact portion (20A) of said carriage and a centre of rotation (10B) for enabling said recording head to be rotated into its mounting position on the carriage, characterised in that said centre of rotation is provided at a position closer to said ink discharge port (10D) than the electrical contact portion (10A) of said recording head and said ink jet cartridge (10) is adapted to be mounted to said carriage (20) by rotation about said centre of rotation (10B) thereby causing said recording head and carriage contact portions to rub together with substantial relative lateral movement and electrical connection to be made between said recording head and cartridge contact portions (10A, 10B). A method of mounting to a carriage (20) of an ink jet recording apparatus having a first electrical contact portion (20a) an ink jet cartridge (10) comprising a recording head (10C) having a discharge port (10D) for discharging ink and having a second electrical contact portion (10A), comprising: mounting said cartridge to said carriage by rotating said ink jet cartridge (10) about a centre of rotation (10B) thereof positioned closer to said ink discharge port (10D) than said second contact portion (10A) to cause said first and said second electrical contact portions to be brought into contact and rubbed together with substantial relative lateral movement and to establish an electrical connection between said first and said second electrical contact portions. A method according to claim 16, wherein said first electrical contact portion is elastically supported and said substantial relative lateral movement between said first and said second electrical contact portions (10a, 20a) results from the displacement of said elastically supported first electrical contact portion (20a).

Inventors: BEKKI TOSHIHIKO, HIRANO HIROFUMI, KASHIMURA MAKOTO, KIMURA TETSUO, BEKKI, TOSHIHIKO, HIRANO, HIROFUMI, KASHIMURA, MAKOTO, KIMURA, TETSUO, BEKKI, TOSHIHIKO, C/O CANON K.K., HIRANO, HIROFUMI, C/O CANON K.K., KASHIMURA, MAKOTO, C/O CANON K.K., KIMURA, TETSUO, C/O CANON K.K.
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1989
Main classification: B41J25
IPC codes: B41J25, B41J2