Patent Publication Number: US-8109610-B2

Title: Liquid ejecting head and liquid ejecting apparatus usable therewith

Description:
This is a division of U.S. patent application Ser. No. 11/140,999, filed Jun. 1, 2005. 
    
    
     FIELD OF THE INVENTION AND RELATED ART 
     The present invention relates to a liquid ejecting head for ejecting liquid such as ink and a liquid ejecting apparatus using the same. The liquid ejecting apparatus is applicable to an ordinary printer which effects recording by ejecting ink, a copying machine, a facsimile machine having a communication system, a multi-function recording device having such functions in combination, or the like, and in addition to an apparatus for forming a figure or a pattern by ejecting liquid other than ink. 
     It has been proposed that an ink jet recording head, which is a typical one of liquid ejecting heads, is provided on an ink jet recording substrate with a ROM (Read Only Memory) to store data such as individual information for the particular head such a its ID (Identity), a particular driving property of its ink ejecting mechanism. For example, Japanese Laid-open Patent Application Hei 3-126560 discloses an ink jet recording head having an EEPROM (Electrically Erasable Programmable ROM). 
     It is known that heat generating resistors for generating energy for ink ejection are constituted in a plurality of lamination film layers on a base portion of an ink jet recording substrate of the ink jet recording head, and a resistance indicative of information particular to the head (or individual information) is formed. This is useful when the amount of the information to be stored is relatively small. The particular information of the head is acquired by the ink jet recording apparatus, on which the ink jet recording head is mounted, reading the value of the resistance of the resistor formed on the base substrate, on the basis of which the ink jet recording apparatus side can effect optimum drive controls for the liquid ejection from the ink jet recording head. 
     Japanese Laid-open Patent Application Hei 6-91877 discloses that when the lamination film layers constituting the ink ejection portion are formed on the base substrate for manufacturing the ink jet recording head, a fuse (ROM) is simultaneously formed. By selectively melting the fuse by controlling a logic circuit formed simultaneously, binary data can be written and stored on the basis of the state of the fuse. 
     With the ink jet head using such an ink jet recording substrate, the particular information of the head is stored, and still, the structure is simplified, and the production property and cost saving is good. 
     In the case of such an ink jet recording head as is capable of recording the information, a measure should be taken against static electricity. Particularly, in the case of an ink jet recording head detachably mountable to a main assembly of the ink jet recording apparatus, the ink jet recording head is necessarily touched by the user&#39;s hand or fingers upon the mounting thereof to the main assembly of the apparatus. For example, when the head and the ink container are integral, an ink jet recording head is mounted each time the ink in the ink container is used up, and the head is touched by the user&#39;s hand or fingers each time of the mounting. When an ink jet recording apparatus is selectively usable as a normal image quality recording machine or as a photographic (high image quality) recording machine by replacing the recording head with that of another kind, the ink jet recording head is touched by the user each time of replacement. In such operations, it is desirable to protect the ink jet recording head from static electricity. For such a purpose, Japanese Laid-open Patent Application Hei 07-060953 discloses provision of an electrical discharge circuit around contact pads for electrical connection with the main assembly of the ink jet recording apparatus. 
     However, the conventional ink jet recording head capable of storing the information involves the following problems. 
     The ink jet recording head having the storing element such as a ROM or EEPROM disclosed in Japanese Laid-open Patent Application Hei 3-26560 or Japanese Laid-open Patent Application Hei 6-91877 unavoidably has a complicated structure, and therefore, various improvements for a high production property or for reduction in size and weight are desired. Fundamentally, a ROM chip is advantageous when the amount of recording data is large, but it is disadvantageous when the amount is small. 
     In addition, the problem of the static electricity is not taken into account. When the size of the storing element for storing the particular information on the head substrate, the contact for outputting the particular information of the head is relative weaker against the static electricity, and therefore, there is a liability that the storing element is broken, or the content of the stored information is changed when the head is touched by the user. In view of this, measurement against the static electricity is important. 
     In the ink jet recording head disclosed in Japanese Laid-open Patent Application Hei 07-06095 33, the influence of the static electricity can be avoided, but it is required to provide a discharge circuit on the substrate separately. For this reason, improvements in the space efficiency, downsizing and/or cost reduction are desired. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention can provide a liquid ejecting head and a liquid ejecting apparatus usable therewith, wherein the influence of the static electricity is suppressed with a simple structure. 
     The present invention can also provide a liquid ejecting head and a liquid ejecting apparatus wherein the discharge during handling of the liquid ejecting head more easily occurs to a voltage source contact pad or a grounding contact pad than to an information output contact pad, by which the problem of the breakdown of unintentional overwriting or rewriting of the information in the storing element due to the electric discharge is minimized. 
     According to an aspect of the present invention, there is provided a liquid ejecting head for ejecting liquid, comprising an electric wiring member including a plurality of contact pads which are electrically contactable to a liquid ejecting apparatus; a storing element for storing individual information; a liquid ejection member, provided with an ejection outlet for ejecting the liquid, for ejecting the liquid using electric energy supplied through a part of said plurality of contact pads, wherein said contact pads include an information contact pad electrically connected with said storing element, a voltage source contact pad for supplying the electric energy and a grounding contact pad, and said voltage source contact pad or said grounding contact pad is disposed at each of both sides of said information output contact pad, with no individual information contact pad which is electrically contactable to the liquid ejecting apparatus therebetween. 
     These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a wiring substrate of an ink jet recording head according to a first embodiment of the present invention. 
         FIG. 2  is a schematic view of a wiring substrate of an ink jet recording head according to a second embodiment of the present invention. 
         FIG. 3  is a schematic view of a wiring substrate of an ink jet recording head according to a third embodiment of the present invention. 
         FIG. 4  is a schematic view of a wiring substrate of an ink jet recording head according to a fourth embodiment of the present invention. 
         FIG. 5  is a perspective view illustrating a first ink jet recording head using the wiring substrate shown in  FIG. 2 . 
         FIG. 6  is an exploded perspective view of an ink jet recording head shown in  FIG. 5 . 
         FIG. 7  is a partly broken perspective view of a first recording element substrate constituting the ink jet recording head shown in  FIG. 5 . 
         FIG. 8  is a perspective view illustrating the second ink jet recording head using a wiring substrate for the ink jet recording head of  FIG. 1 . 
         FIG. 9  is an exploded perspective view of an ink jet recording head shown in  FIG. 8 . 
         FIG. 10  is a partly broken perspective view of a second recording element substrate constituting the ink jet recording head shown in  FIG. 8 . 
         FIG. 11  is a schematic view of a Si substrate including a fuse for storing peculiar information of the head and peripheral circuits therefor, according to the present invention. 
         FIG. 12  is a schematic top plan view of an inside of an example of a recording device usable with the ink jet recording head according to the present invention. 
         FIG. 13  is a schematic view illustrating an ESD experiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The description will be made as to the embodiments of the present invention in conjunction with the accompanying drawings. 
       FIG. 5  to  FIG. 12  illustrate an ink jet recording head or an ink jet recording apparatus which is a liquid ejecting head or a liquid ejecting apparatus according to the present invention. The respective constituent-elements will be described. 
     The recording head of this embodiment is of a type integral with an ink container, and may be a first recording head H 1000  filled with black ink, as shown in (a) and (b) of  FIG. 5 , and may be a second recording head H 1001  filled with color inks (cyan ink, magenta ink and yellow ink), as shown in (a) and (b) of  FIG. 8 . The recording head H 1000  or H 1001  is securely supported on a carriage  102  of a main assembly of the ink jet recording apparatus by positioning means and electrical contacts, and is detachably mountable to the carriage  102 . When the ink is used up, the recording head can be replaced. 
     The description will be made as to the structures of the recording heads H 1000  and H 1001  in detail. 
     (Recording Head) 
     The first recording head H 1000  and the second recording head H 1001  are both of a type using an electrothermal transducer for generating thermal energy for creating film boiling in the ink in response to an electric signal, and the electrothermal transducer functions as a recording element and is disposed opposed to an ink ejection outlet. In this embodiment, the recording head integrally comprises a recording element substrate for ejecting the ink (in this embodiment, the liquid ejection member is provided with ejection outlets for ejecting the liquid, and the liquid is ejected using the supplied electric power), and an ink container for retaining and storing the ink to be supplied to the recording element substrate. However, the present invention is applicable also to a recording head not having the ink container integrally. 
     (1) First Recording Head H 1000 : 
       FIG. 6  is an exploded perspective view of the first recording head H 1000 . The first recording head H 1000  comprises a first recording element substrate H 1100 , an electric wiring member (electric wiring sheet) H 1300 , and an ink retention member H 1500 . 
       FIG. 7  is a partly broken perspective view of the first recording element substrate H 1100 . 
     The first recording element substrate H 1100  is constituted by a Si substrate H 1110  having a thickness of 0.5 mm-1 mm, in which ink supply port H 1102  in the form of an elongated through-opening (ink flow path) is formed. The ink supply port  1102  of the first recording element substrate H 1100  is in fluid communication with the ink supply port H 1200  of the ink retention member H 1500  by bonding and fixing the first recording element substrate H 1100  to the ink retention member H 1500  with high precision. 
     The Si substrate H 1110  is provided with an array of electrothermal transducer elements H 1103  at each lateral side of the ink supply port H 1102 , so that arrays interpose the ink supply port H 1102 , and there are further provided unshown electric wiring of Al and the like for supplying electric power to the electrothermal transducer elements H 1103 . 
     The Si substrate H 1110  is provided along edge portions adjacent opposite ends of the arrays of the electrothermal transducer elements H 1103  with electrode portions H 1104  for supplying the electric power to the electric wiring and for supplying the electric signals for driving the electrothermal transducer elements H 1103 , and bumps H 1105  of Au are formed at the tops of the electrode portions H 1104 . 
     The Si substrate H 1110  is further provided with a fuse and a peripheral circuit therefor formed thereon, the fuse being effective to store the peculiar information of the head.  FIG. 11  show the fuse and the peripheral circuit. 
     In  FIG. 11  the fuse is indicated by a reference H 1117 . In this example, four fuses H 1117  of polysilicon resistor are disposed adjacent a short side of the ink supply port H 1102 . Each of the fuses H 1117  is connected with a second driving element H 1118  for melting the fuse and reading the information corresponding to the melting or non-melting of the fuse. The second driving element H 1118  is disposed adjacent to the first driving element H 1116  for driving the electrothermal transducer element H 1103 . 
     A signal for selecting the first driving element H 1116  for driving the electrothermal transducer element H 1103  is used as the signal for selecting the second driving element H 1118  for driving the fuse H 1117  as it is. Therefore, the circuit portion for selecting the second driving element H 1118  can be formed with the structure similar to the circuit portion for selecting the first driving element H 1116 . More particularly, the portion from the signal line to which the signal is inputted outside the ink jet recording substrate to the signal line connected to the second driving element H 1118  through a shift register, a latching circuit and a decoder, may be common circuit structure with the circuit for selecting the first driving element H 1116 . The selection circuit H 1112  for finally selecting the second driving element H 1118  on the basis of the output from the shift register or the like, has a structure similar to the selection circuit for the first driving element H 1116 . 
     A VH pad H 1104   c  for supplying a voltage from a VH voltage source is connected with the electrothermal transducer element H 1103  through the VH wiring lead H 1114 . A GNDH pad H 1104   d  for connection with the GNDH voltage source is commonly connected to the second driving element H 1118  connected with the fuse H 1117  and the first driving element H 1116  connection to the electrothermal transducer element H 1103  through the GNDH wiring lead H 1113 . Namely, the GNDH wiring lead H 1113  is common for the first driving element H 1116  and the second driving element H 1118 . 
     When the fuse H 1117  is to be melted, the ID pad H 1104   a  functions as a fuse cutting voltage source contact for applying a melting voltage, and when the information indicated by the fuse is to be read out, it functions as a signal output contact. More particularly, when the fuse H 1117  is to be melted, a voltage (a driving voltage 24V for the electrothermal transducer element, for example) is applied to the ID pad H 1104   a  to instantaneously disconnect the corresponding fuse H 1117  by actuating the second driving element H 1118  selected by the selection circuit. At this time, the electrical conduction between the ID voltage source pad H 1104   b  for reading the information of the fuse out and the outer circuit such as the voltage source for reading the fuse information, is disconnected. 
     On the other hand, when the information is to be read out, the ID voltage source pad H 1104   b  is supplied with a voltage (power source voltage 3.3V of a logic circuit, for example), so that when the fuse H 1117  is disconnected, the potential of the ID voltage source pad H 1104   b  and that of the ID pad H 1104   a  are equal to each other, and therefore, a Hi level voltage is outputted from the ID pad H 1104   a . When the fuse H 1117  is not melted, a Lo level voltage is outputted from the ID pad H 1104   a  since the fuse H 1111  has a resistance value which is far larger than the resistance value of the fuse H 1117 . 
     In another example, the fuse H 1117  is replaced with a simple wiring on the Si substrate H 1110 , and the presence or absence of such wiring may indicate information to be stored and read out. In such a case, the peculiar information of the head is written during film formation for the wiring lead on the Si substrate H 1110 . The reading of the information is exactly the same as the foregoing example, but it is not possible to write information after the formation. 
     In a further example, a resistance element representing information peculiar to the head is formed on the Si substrate H 1110 , and one end of the resistance element is connected to the ID pad H 1104   a , and the other end is connected to the GNDH pad H 1104   d . In such a case, the main assembly of the ink jet recording apparatus reads a resistance value between the ID pad H 1104   a  and the GNDH pad H 1104   d  to acquire the peculiar information of the head corresponding to the resistance value. 
     In any of such examples, structure of resin material having an ink flow path is formed, for each of the electrothermal transducer elements H 1103 , on such a side of the Si substrate H 1110  as is provided with the fuses, the wiring pattern or the resistance element through a photolithography. The structure has an ink flow passage wall H 1106  for defining each of the ink flow paths and a ceiling portion covering the top part thereof, and in the ceiling portion, ejection outlets H 1107  are formed. The ejection outlets  1107  are provided opposed to the respective ones of the electrothermal transducer elements H 1103 , thus constituting a group of ejection outlets H 1108 . 
     In the first recording element H 1100  thus constituted, the ink supplied from the ink flow path H 1102  is ejected through the ejection outlet  1107  opposed to the corresponding electrothermal transducer element H 1103  by the pressure of the creation of the bubble caused by heat generation of the electrothermal transducer element H 1103 . 
     The electric wiring sheet H 1300  is to constitute the electric signal path for applying the electric signal for ejecting the ink to the first recording element substrate H 1100 , and is formed of a polyimide base material and a wiring lead pattern of copper foil thereon. Also, an opening H 1303  for setting the first recording element substrate H 1100  is formed, and adjacent the edge of the opening, an electrical contact for connection with the electrode portion H 1104  of the first recording element substrate H 1100 . Furthermore, the electric wiring sheet H 1300  is provided with an external signal input contact for receiving the electric signal from the main assembly apparatus, and an external signal input contact H 1302  and the electrical contact H 1304  are electrically connected with each other by a continuous wiring lead pattern of copper foil. 
     The electrical connection between the electric wiring sheet H 1300  and the first recording element substrate H 1100  are electrically connected by an ultrasonic heat crimping method between the bump H 1105  formed at the electrode portion H 1104  of the first recording element substrate H 1100  and the electrical contact H 1304  of the electric wiring sheet H 1300  corresponding to the electrode portion H 1104  of the first recording element substrate H 1100 . 
     On a flat surface around the first recording element substrate H 1100  fixed at the ink retention member H 1500  (that is, the surface faces to the recording material when the recording head H 1000  is mounted on the carriage  102 ), a back side of a part of an electric wiring tape H 1300  is fixed by adhesive material. An unbonded portion of the electric wiring tape H 1300  is bent and is fixed by an adhesive material on a side surface substantially perpendicular to the bonding surface of the ink retention member H 1500  for the first recording element substrate H 1100 . 
     (2) Second Recording Head H 1001   
     The second recording head H 1001  functions to eject three color inks, namely, the cyan ink, the magenta ink and the yellow ink. As shown in  FIG. 9  which is an exploded perspective view, the second recording head H 1001  comprises a second recording element substrate H 1101 , an electric wiring sheet H 1301  (electric wiring member), and an ink retention member H 1501 . The structures of the second recording head H 1001  are similar to the first recording head H 1000  described in the foregoing. 
       FIG. 10  is a partly broken perspective view to illustrate the structure of the second recording element substrate H 1101 . In the second recording element substrate H 1101 , three ink supply ports H 1102  for the cyan ink, the magenta ink and the yellow ink are formed and are extended in parallel with each other, as is different from the first recording element substrate H 1100 . At respective lateral sides of each of the ink supply port H 1102 , electrothermal transducer elements H 1103  and ejection outlets H 1107  are arranged staggered, generally along a line. On the Si substrate H 1110   a , similarly to the Si substrate H 1110  of the first recording element substrate H 1100 , electric wiring, fuses or resistances and electrode portions are formed. On the Si substrate H 1110   a , ink flow passage walls H 1106  and ejection outlets H 1107  are formation of resin material through a photolithography. At the electrode portion H 1104  for supplying the electric power to the electric wiring, bumps H 1105  of Au or the like are formed. 
     (Ink Jet Recording Apparatus) 
     The description will be made as to a recording device on which the above-described recording head is mountable.  FIG. 12  is a schematic top plan view of an inside of an example of a recording device usable with the ink jet recording head of the present invention. 
     As will be understood from  FIG. 12 , the recording device comprises a carriage  102  on which the recording head H 1000  shown in  FIG. 5  and the recording head H 1001  shown in  FIG. 8  are removably mountable at a correct position. The carriage  102  is provided with an electrical connecting portion for transmitting driving signals or the like to the respective ejection portions through the external signal input contact provided on the recording heads H 1000  and H 1001 . 
     As shown in  FIGS. 5 and 8 , the first recording head H 1000  and the second recording head H 1001  are guided to a predetermined position in the carriage  102  by a mounting guide H 1560  for guiding the recording head to the head mounting position in the carriage  102  and by an engaging portion H 1930  for fixed in g the ink jet recording head H 1000  relative to the ink jet recording apparatus, and then is fixed at the position. The ink jet recording head H 1000  is provided with an abutting portion H 1570  for positioning itself to the predetermined mounting position in the carriage  102  in a X direction (carriage scanning direction), an abutting portion H 1580  for a Y direction (a recording media feeding direction), and an abutting portion H 1590  for the Z direction (ink ejecting direction). By these abutting portions, the recording head H 1000  is correctly positioned relative to the carriage  102 , so that proper electrical contact is established between the external signal input contacts H 1302  provided on the electric wiring sheets H 1300  and H 1301  and the contact pins of the electrical connecting portion provided in the carriage  102 . 
     The carriage  102  is support for reciprocal motion along the guiding shaft  103  provided in the main assembly of the apparatus and extended in the main scan direction. The recording heads H 1000  and H 1001   a  carried on the carriage  102  such that direction in which the ejection outlets of each of the ejection portions are arranged crosses with the scanning direction of the carriage  102 . The liquid is ejected from the ejection outlet arrays onto the recording material  108  fed to the position facing the ejection outlets by a pick-up roller  131  and a feeding roller  109 . 
     By replacing the recording head H 1000  with recording heads each having the same structures as the recording head H 1001  but containing light magenta ink, light cyan ink and black ink, respectively, the printer can be operated as a photographic high image quality printer. 
     (Results of ESD (Electrostatic Discharge) Experiments) 
     ESD experiments have been carried out with the second recording element substrate H 1101  having the circuit shown in  FIG. 11 . The results are shown in Table 1. 
     The electric wiring sheet H 1301  under the experiments has the ID contact pad H 1302   a , the VH contact pad H 1302   c , the GNDH contact pad H 1302   d  at the positions shown in  FIG. 13 . More particularly, the VH contact pad H 1302   c  are disposed at one side of the ID contact pad H 1302   a , and the GNDH contact pad H 1302   d  are disposed at the other side. The opening dimensions of each of the contact pad are 1.3 mm×1.3 mm and are arranged at the interval of 2.0 mm. The base material of the electric wiring sheet H 1301  is polyimide, and a plurality of wiring lines of copper foil are electrically connected to the ID pads H 1104   a , the VH pads H 1104   c  and the GNDH contact pads H 1104   d , respectively. 
     In  FIG. 13 , a semispherical test contact  140  is caused to approach to the ID contact pad H 1302   a  at the position right above the ID contact pad H 1302   a  and is supplied with the voltage of +20 kV, and the electric discharging to the respective contact pads are observed. The experiments are carried out with four samples, and the results are as follows. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 (Occurrences of electric discharge) 
               
            
           
           
               
               
            
               
                   
                 Locations 
               
            
           
           
               
               
               
               
            
               
                   
                 ID pad 
                 VH pad 
                 GNDH pad 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Sample 1 
                 Yes 
                 Yes 
                 No 
               
               
                   
                 Sample 2 
                 No 
                 No 
                 Yes 
               
               
                   
                 Sample 3 
                 No 
                 Yes 
                 No 
               
               
                   
                 Sample 4 
                 No 
                 Yes 
                 Yes 
               
               
                   
                 Frequencies of 
                 1/4 
                 3/4 
                 2/4 
               
               
                   
                 occurrences 
               
               
                   
                   
               
            
           
         
       
     
     The results of experiments show that although the discharge is tried aiming at the ID contact pad H 1302   a , the discharge occurred to the ID contact pad H 1302   a  only in one of the four samples. Therefore, it is understood that discharge to the ID contact pad can be effectively impeded by the existence of the VH contact pad and/or the GNDH contact pad adjacent the ID contact pad. In the case of sample 1 with which the discharge occurred to the ID contact pad, the discharge to the VH contact pad also occurred simultaneously. From this result, it is understood that discharge to the ID contact pad is diffused by the existence of the adjacent VH contact pad and/or GNDH contact pad. 
     In the foregoing description, the storing element is provided in the recording element substrate. But, similar effects are provided when a similar storing element is provided in another substrate. 
     As described in the foregoing, in the recording head of this embodiment, one or both of the VH contact pad and the GNDH contact pad are disposed at both of the sides of the ID contact pad adjacent thereto, so that discharge to the ID contact pad is effectively impeded. By doing so, the adverse influence, to the storing element, of the static electricity attack upon contact of the user&#39;s hand or finger to the head when the head is mounted to the carriage or to the main assembly of the apparatus, is prevented. Recently, the circuit on the substrate for the ink jet recording is improved, it is quite durable against the static electricity, and therefore, the countermeasurement against the static electricity would be sufficient if the disposition of the contact pad of these embodiments of the present invention are employed. 
     The description will be made as to the positional relation among the ID contact pad, the VH contact pad and the GNDH contact pad with more specific examples. 
     Embodiment 1 
     Referring to  FIG. 1 , the description will be made as to an ink jet recording head according to the first embodiment of the present invention. 
       FIG. 1  is an enlarged view of the external signal input contact portion of the electric wiring sheet of the second recording head used with the ink jet recording head of this embodiment. Referring to  FIG. 1 , the electric wiring sheet H 1301  is provided with 32 external signal input contacts H 1302 . Of these external signal input contacts H 1302 , six pads are ID contact pads H 1302   a  which are disposed substantially at the central portion of the portion where the external signal input contacts H 1302  are disposed. The ID contact pads H 1302   a  are respectively connected to the ID pads connected with the fuse H 1117  (a simple connecting line or the resistance element ( FIG. 11 )) provided at the opposite ends of each of the three ink supply ports H 1102  of the second recording element substrate H 1101  shown in  FIG. 10 . 
     Six VH contact pads H 1302   c  are disposed along one side of the array of the ID contact pads H 1302   a  (the side above the array of the ID contact pads H 1302   a  in  FIG. 1 ) adjacent the ID contact pad H 1302   a  array. More particularly, in this embodiment, the VH contact pads H 1302   c  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). These VH contact pads H 1302   c  are electrically connected to the VH pads H 1104   c  ( FIG. 11 ) provided in the electrode portion H 1104  ( FIG. 10 ) at the opposite ends of the second recording element substrate H 1101 . 
     Six GNDH contact pads H 1302   d  are arranged along the array of the ID contact pads H 1302   a  on the other side, that is, the side below the array of the ID contact pads H 1302   a  in  FIG. 1 . More particularly, in this embodiment, the GNDH contact pads H 1302   d  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). These VH contact pads H 1302   d  are electrically connected to the GNDH pads H 1104  ( FIG. 11 ) provided in the electrode portion H 1104  ( FIG. 10 ) at the opposite ends of the second recording element substrate H 1101 . 
     The other external signal input contacts H 1302  other than the ID contact pads H 1302   a , the VH contact pads H 1302   c  and the GNDH contact pad H 1302   d , are used for electric power supply to the transistors, sending and receiving signals such as control signals or the like. 
     In the case of the ink jet recording head of the present invention, the ID contact pads H 1302   a  which are relative weak against the attach of static electricity are positioned substantially at the central portion of the external signal input contact portion H 1302 . This position is hard to be touched by the user, when the user manipulates the second recording head by hand. Usually, the user is more or less conscious so as not to touch the external signal input contact H 1302 , and therefore, the pads disposed at the center portion is not easily touched. 
     In addition, the ID contact pads H 1302   a  are adjacent to and interposed between the VH contact pad H 1302   c  and the GNDH contact pad H 1302   d , and therefore, if an electrically charged finger of the user is brought so close to the ID contact pad H 1302   a  that electrical discharge occurs, the discharge tends to be toward the VH contact pad H 1302   c  and/or to the GNDH contact pad H 1302   d  rather than toward the ID contact pad H 1302   a . Thus, the structure of the present invention is such that peculiar information in the head is not broken, overwritten or rewritten. 
     Embodiment 2 
     Referring to  FIG. 2 , the description will be made as to an ink jet recording head according to a second embodiment of the present invention. 
       FIG. 2  is an enlarged view of an external signal input contact portion of electric wiring of a first recording head usable with an ink jet recording head according to this embodiment. Referring to  FIG. 2 , the electric wiring sheet H 1300  is provided with 21 external signal input contacts H 1302 . The first recording head is for the black ink, and therefore, the numbers of the electric power supply contacts, the control signal contacts are smaller than the second recording head for the cyan, magenta and yellow inks, as described in the first embodiment. 
     However, the carriage  102  of the main assembly of the ink jet recording apparatus is capable of accepting the third recording head which is for the photographic printing and which has the same structure as the second recording head, at the position where the first recording head is removed. Therefore, the positions of the 21 external signal input contacts H 1302  correspond to the positions of the external signal input contacts H 1302  of the second recording head when the head is mounted to the carriage  102 . 
     The number of the ID contact pads H 1302   a  of the external signal input contacts H 1302  on the electric wiring sheet H 1300 , six, and the positions thereof are substantially at the center of the portion where the external signal input contacts H 1302  are provided. The ID contact pads H 1302   a  are connected to the ID pads which in turn is connected to a fuse H 1117 , a simple wiring line or a resistance element,  FIG. 11 ) disposed at each of the opposite ends of the ink supply port H 1102  of the first recording element substrate H 1100 . 
     Four VH contact pads H 1302   c  are arranged along and adjacent to the array of the ID contact pad H 1302   a  at one lateral side (above the array of the ID contact pads H 1302   a  in  FIG. 2 . More particularly, in this embodiment, the VH contact pads H 1302   c  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). The VH contact pads H 1302   c  are connected to the VH pads H 1104   c  ( FIG. 11 ) provided in the electrode portion H 1104  ( FIG. 7 ) disposed at the opposite ends of the first recording element substrate. 
     Four GNDH contact pads H 1302   d  are arranged along and adjacent to the array of the ID contact pad H 1302   a  at one lateral side (below the array of the ID contact pads H 1302   a  in  FIG. 2 . More particularly, in this embodiment, the GNDH contact pads H 1302   d  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). The GNDH contact pads H 1302   d  are connected to the GNDH pads H 1104  ( FIG. 11 ) provided in the electrode portion H 1104  ( FIG. 7 ) at the opposite ends of the recording element substrate H 1100 . 
     The other external signal input contacts H 1302  other than the ID contact pads H 1302   a , the VH contact pads H 1302   c  and the GNDH contact pad H 1302   d , are used for electric power supply to the transistors, sending and receiving signals such as control signals or the like. 
     According to the ink jet recording head of this embodiment, similarly to the first embodiment, the ID contact pads H 1302   a  which are relative weak against the attach of static electricity are positioned substantially at the central portion of the external signal input contact portion H 1302 , and therefore, the user does not easily touch the ID contact pad H 1302   a.    
     In addition, the ID contact pads H 1302   a  are adjacent to and interposed between the VH contact pads H 1302   c  and the GNDH contact pads H 1302   d , and therefore, even when if an electrically charged finger of the user is brought so close to the ID contact pad H 1302   a  that electrical discharge occurs, the discharge tends to be toward the VH contact pad H 1302   c  and/or to the GNDH contact pad H 1302   d  rather than toward the ID contact pad H 1302   a , and therefore, the peculiar information in the head is not easily broken, overwritten or rewritten. 
     Embodiment 3 
     Referring to  FIG. 3 , the third embodiment will be described. 
       FIG. 3  is an enlarged view of the external signal input contact portion of the electric wiring sheet of the second recording head used with the ink jet recording head of this embodiment. A second type recording head of this embodiment uses the second recording element substrate H 1101  which is the same as the first embodiment, and the difference from the first embodiment is only in the disposition of the external input contacts H 1302  on the external electric wiring. 
     Six pads of 32 external signal input contacts H 1302  provided on the electric wiring sheet H 1301  are ID contact pads H 1302   a . The ID contact pads H 1302   a  are arranged in a longitudinal direction (in the direction of the length of the electric wiring sheet H 1301 ) at the center of the portion where the external signal input contacts H 1302  are provided. 
     Along the array of the ID contact pads H 1302   a , six VH contact pads H 1302   c  are arranged adjacent thereto at one lateral side thereof, and six GNDH contact pads H 1302   d  are arranged adjacent thereto at the other lateral side thereof. More particularly, in this embodiment, the VH contact pads H 1302   c  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween), and the GNDH contact pads H 1302   d  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). 
     According to the ink jet recording head of this embodiment, similarly to the first embodiment, the ID contact pads H 1302   a  which are relative weak against the attach of static electricity are positioned substantially at the central portion of the external signal input contact portion H 1302 , and therefore, the user does not easily touch the ID contact pad H 1302   a.    
     In addition, the ID contact pads H 1302   a  are adjacent to and interposed between the VH contact pads H 1302   c  and the GNDH contact pads H 1302   d , and therefore, even if an electrically charged finger of the user is brought so close to the ID contact pad H 1302   a  that electrical discharge occurs, the discharge tends to be toward the VH contact pad H 1302   c  and/or to the GNDH contact pad H 1302   d  rather than toward the ID contact pad H 1302   a , and therefore, the peculiar information in the head is not easily broken, overwritten or rewritten. 
     Embodiment 4 
     Referring to  FIG. 4 , an ink jet recording head according to a fourth embodiment will be described. 
       FIG. 4  is an enlarged view of the external signal input contact portion of the electric wiring sheet of the second recording head used with the ink jet recording head of this embodiment. A second type recording head of this embodiment uses the second recording element substrate H 1101  which is the same as the first embodiment, and the difference from the first embodiment is only in the disposition of the external input contacts H 1302  on the external electric wiring. 
     Six pads of 32 external signal input contacts H 1302  provided on the electric wiring sheet H 1301  are ID contact pads H 1302   a . The ID contact pads H 1302   a  are disposed substantially at the central portion of the portion where the external signal input contacts H 1302  are provided. Around the ID contact pads H 1302   a  (above, below, left side and right side of the ID contact pads H 1302   a  in  FIG. 4 ), the VH contact pads H 1302   c  and/or the GNDH contact pads H 1302   d  are disposed at positions adjacent thereto. Each of the ID contact pads H 1302   a  is are interposed between the VH contact pads H 1302   c  and the GNDH contact pads H 1302   d  in the longitudinal direction and in the transverse direction. In other words, two arrays of three ID contact pads H 1302   a  extend inclined at the central portion of the portion where the external signal input contacts H 1302  are provided, and three arrays which comprise six VH contact pads H 1302   c  and six GNDH contact pads H 1302   d  extend so as to interpose the respective ones of the arrays of the ID contact pads H 1302   a.    
     According to the ink jet recording head of this embodiment, each of the ID contact pads H 1302   a  are interposed between the VH contact pads. H 1302   c  or the GNDH contact pads H 1302   d  which are disposed around it, more particularly, at the top, bottom, left and right. For this reason, the peculiar information in the head of this embodiment is less easily broken, overwritten or rewritten then in the heads of the other embodiments. More particularly, in this embodiment, the VH contact pads H 1302   c  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween), and the GNDH contact pads H 1302   d  are immediately adjacent to the ID contact pad H 1302   a  array (namely, with no ID contact pad H 1302   a  therebetween). 
     The ink jet recording head of any of the foregoing embodiments is not limited to those of the ejecting types, but is applicable to the ink jet recording heads of various ink ejecting types. 
     The external signal input contacts in any of the foregoing embodiments, may be a pad connected to the similar set of pads. As to the ID contact pads, they may be usable as information writing pads when the storing element is an information writable (not only readable) element. 
     According to the foregoing embodiments, the problem of the overwriting or rewriting of individual information in the storing element due to the static electricity upon the head mounting, can be solved. 
     While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims. 
     This application claims priority from Japanese Patent Application No. 164555/2004 filed Jun. 2, 2004, which is hereby incorporated by reference.