Liquid container and recording apparatus

A liquid container containing ink, which is detachably mountable to a carriage, the improvement residing in the provision of an optical medium to which information is writable using visible light and from which the information is readable.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to a liquid container for storing liquid, for example, ink, etc. In particular, it relates to a liquid container to be employed by a recording apparatus in order to record an image or the like on recording medium, for example, recording paper, by ejecting ink onto the recording medium. It also relates to a recording apparatus employing such a liquid container.

Generally, a recording head with which an ink jet recording apparatus is provided has ink ejection orifices from which droplets of ink are ejected. It records letters, pictures, etc., on recording medium by ejecting droplets of ink onto the recording medium while being moved relative to the recording medium in a manner to scan the recording medium. More specifically, a recording head is mounted on a carriage, which is reciprocally moved following a predetermined path (primary scan direction). After each reciprocal movement of the carriage in the primary scanning direction recording medium is moved a predetermined distance in the direction (secondary scan direction) perpendicular to the moving direction of the carriage. Ordinarily, a recording head is structured so that it can be removably mounted on a carriage, or so that an ink container for storing the ink to be supplied to a recording head is structured so that it can be removably connected to a recording head.

It has been a common practice to provide an ink jet recording apparatus with an ink remainder amount detecting means. That is, a sensor is attached to the main assembly of an ink jet recording apparatus, and as a carriage is moved, the amount of the ink remainder in an ink container is automatically detected by the sensor, and a user is warned if it is detected that the amount of the ink in the ink container has reduced to a critical value or below. There are various ink remainder amount detecting means. For example, some ink remainder amount detecting means comprise a pair of electrodes placed in an ink container so that the presence or absence of ink can be detected by measuring the amount of the electrical conductivity between the pair of electrodes, whereas others optically detect the ejected droplets of ink.

As for an ink jet recording head and an ink container therefor, in accordance with the prior arts, there are those equipped with a means for optically detecting the amount of the ink therein (which are disclosed in Patent Documents 1 and 2, for example). However, it is only with predetermined intervals that these detecting methods can detect the amount of ink remainder; it is very difficult to continuously detect the amount of ink remainder with the use of these detecting methods. In other words, with the use of these detecting methods, it is difficult to show the amount of the ink remainder in an ink container in the analog fashion.

Thus, it is common practice to use a method, in which the total amount of the liquid ejected in the form of a droplet from a recording head is counted, and the amount of the ink remaining in an ink container is calculated based on the counted total amount of the ink ejected from the ink container, in conjunction with a method capable of displaying the amount of the ink remaining in the ink container in the analog fashion.

However, many ink containers are structured so that they can be removably mounted on a carriage, as described above. Thus, there is the possibility that as a given ink container is replaced with another ink container, the information, that is, the amount of the ink remainder, which has been detected, and stored, by the main assembly of an ink jet recording apparatus from which the given ink container has just been removed, will contradict with the amount of the ink in the replacement ink container.

For example, some ink jet recording apparatuses are systemized in such a way that, as a partially emptied ink container is replaced with another ink container, the ink container replacement operation is detected by a sensor, and the information on the main assembly side of an ink jet recording apparatus regarding the ink remainder level is reset. In other words, in the case of these recording apparatuses, even if the replacement ink container is not a brand-new one, that is, a partially empty one, the system treats the replacement ink container as a brand-new one, resetting thereby the information regarding the ink remainder level. As a result, the actual amount of the ink in the replacement ink container does not coincide with the displayed amount of ink remainder.

Thus, it has been proposed to provide an ink container with a memory element or the like as information storage so that the amount of the ink remaining in an ink container can be stored in the memory element of the ink container itself, in order to make it possible to accurately display the ink remainder level even if a given partially empty ink container is replaced with an ink container which is not full (for example, Patent Documents 3 and 4):Patent Document 1: Japanese Laid-open Patent Application 2-102062Patent Document 2: Japanese Laid-open Patent Application 7-218321Patent Document 3: Japanese Laid-open Patent Application 9-309213Patent Document 4: Japanese Patent 2752402.

However, the ink containers in accordance with the prior arts, disclosed in the above listed documents have a problem. That is, if they are systemized so that information is electrically read from, or written into, their memory elements, for example, a RAM (Random-Access Memory) or the like, the electrical connector portions of the memories are sometimes deteriorated due to the repetition of the mounting or removal of the ink containers, and/or the adhesion of the ink splashes from the recording heads (Patent Documents 3 and 4).

In addition, the information having been electrically written into the memory elements cannot be visually confirmed from outside, being it therefore impossible for a user to find the ink remainder levels of the given ink containers from the ink containers themselves.

SUMMARY OF THE INVENTION

Thus, the primary object of the present invention is to provide a more reliable liquid container than a liquid container in accordance with the prior art, in that information can be more reliably written into, or read from the memory element of the ink container, and also so that the information, for example, the amount of the ink remainder in the ink container, in the memory element of the ink container can be obtained even when the ink container is not in connection with the main assembly of an image forming apparatus.

According to one of the characteristic aspects of the present invention for achieving the above object, a liquid container for internally storing liquid therein and removably mountable on the carriage of an ink jet recording apparatus is provided with an optical storage medium into which information can be written with the use of visible light, and from which information can be read with the use of visible light. In the case of a liquid container structured as described above, information is optically written into, or read from, the optical storage medium, assuring that the electrical contact failure, for example, at the electrical connectors, is prevented. Therefore, the liquid container is more reliable in terms of the operation in which information is written into, or read from, the memory medium of the liquid container. Further, the optical storage medium is disposed in the recess, or opening, of the liquid container, preventing thereby dust, liquid, etc., from adhering to the optical storage medium, further improving the ink container in terms of the reliability with information is written into the optical storage medium, or read therefrom.

According to another characteristic aspect of the present invention, at least a part of the information in the optical storage medium is visible as visible information, making it easier to confirm the information such as the amount of ink remainder directly from the ink container itself.

According to another characteristic aspect of the present invention, the direction in which an ink container is mounted onto a carriage is roughly perpendicular to the direction in which the carriage is primarily moved, and the direction in which information is recorded in the optical storage medium is roughly perpendicular to the direction in which the ink container is mounted onto the carriage. Therefore, even if a portion, or portions, of the information in the optical storage medium cannot be read due to the damages to the optical storage medium, the information read from the optical storage medium can be compensated for, for the missing portions, further improving the ink container in terms of the reliability of the information read from the optical storage medium.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the preferred concrete embodiments of the present invention will be described with reference to the appended drawings.

FIG. 1is a perspective view of the printer in the first embodiment of the present invention, into which an ink container in accordance with the present invention is mounted. As shown inFIG. 1, the recording head2in this printer is connected to the ink container1for supplying the recording head2with ink. InFIG. 1, the recording head2is mounted on the carriage4, being positioned so that ink will be ejected downward in the drawing. An image is recorded on recording medium (unshown), for example, a piece of recording paper or the like, by ejecting droplets of ink from the recording head2while moving the carriage4along the guide shaft3. The carriage4is reciprocally moved in the primary direction, that is, the direction indicated by a arrow mark a or the direction indicated by an arrow mark a2, in the drawing, through the timing belt6, by means of rotationally driving the carriage motor5. Each time the movement of the carriage4(recording head2) in the primary direction is completed, the actual recording operation is briefly interrupted, and the recording medium on the platen7is conveyed a predetermined distance by rotationally driving the recording medium conveyance motor8. Then, the actual recording operation is restarted to complete the next segment of the recording operation, the length of which corresponds to the width of the recording medium.

FIG. 9is a perspective view of the combination of the ink containers and head holder, in accordance with the present invention, showing how the ink containers are mounted into the head holder.FIG. 10is a sectional view of the combination of the ink containers in accordance with the present invention and head holder, in accordance with the present invention, showing how the ink containers are mounted into the head holder. The recording portion inFIG. 9comprises a head holder for holding an ink container, and the recording head2from which ink is ejected. In this drawing, there are four ink containers Bk32, C33, M34, and Y35, which contain black, cyan, magenta, and yellow inks, respectively, and which are mounted on the head holder9to supply the recording head2with the four inks different in color.

FIG.10(1)–FIG.10(4) shows the steps through which each of the ink containers is mounted onto the head holder. The ink container1is provided with a first claw16, a third claw18, a latching lever15, and a second claw17. The first and third claws16and18are on the front side (right side in drawing), and the latch lever15and second claw17are on the rear side (left side in drawing). The second claw7is an integral part of the latch level15. The ink container1is also provided with an ink outlet13for supplying the recording head with ink. The ink outlet13is on the bottom surface (bottom side in drawing) of the ink container1. The head holder9is provided with a supply tube19for delivering ink to the recording head2. The position of the supply tube19corresponds to that of the ink outlet13of the ink container1. FIG.10(1) shows the first step for mounting the ink container onto the head holder9. A user is to mount the ink container onto the head holder9from diagonally above the front side (left side in drawing) of the head holder9. FIG.10(2) shows the next step, in which the third claw18fits into the hole of the head holder9, being fixed in position relative to the head holder9. The next step is shown in FIG.10(3), in which the ink container1is to be pressed, on the rear (left side in drawing) portion of the top surface, in order to cause the ink container to rotate about the third claw18. Then, in the next step shown in FIG.10(4), the first claw16, and the second claw17of the latch lever15, engage with the head holder9, completing the mounting of the ink container1onto the head holder9. As will be evident from the above description, the general direction in which the ink container1is mounted into the head holder9is perpendicular to the primary direction in which the carriage4of the printer is moved.FIG. 2is a schematic side view or the essential portion of the printer, inclusive of the above described head holder and ink container. As shown inFIG. 2, the ink container1is removably mounted in the head holder9integral with the recording head2. The head holder9is removably mounted on the carriage4, being thereby solidly supported by the carriage4. The ink container1comprises an ink container proper1ain which ink is stored, and a housing1bwhich covers the ink container proper1a. The housing1bof the ink container1is provided with a recess1c, which is in the bottom portion of the housing1b, opening in the direction to face the recording medium as the recording medium is conveyed. Within this recess1c, the optical storage medium11into which information such as the amount of the ink remainder in the ink container1, is written, or from which the information is read, is disposed.

Also referring toFIG. 2, the printer is provided with the optical portion10for writing information into the optical storage medium11of the ink container, or reading information from the optical storage medium11. This optical portion10comprises: an information display power source51which emits a beam of laser light for reading the information in the optical storage medium10; an information recording power source which emits a beam of laser light60used for writing information into the optical storage medium11; and a light reception sensor52which catches the light reflected by the optical storage medium11. The information display light source51and information recording light source59both have a semiconductor diode which emits laser light. The light reception sensor52has a photo-diode.

The information recording beam of laser light60emitted from the information recording light source59is converted into parallel rays by the collimator lens62. Then, the parallel rays are reflected by a half-mirror58, and transmitted through a half-mirror57. After being transmitted through the half-mirror57, the parallel rays are reflected (deflected) by a mirror53, and are made to converge on the optical storage medium11of the ink container1.

FIG. 3is a sectional view of the optical storage medium11, andFIG. 4is a sectional view of the recess1cportion of the bottom wall of the ink container1, and the optical storage medium11attached to the bottom surface of the recess1c. As shown inFIGS. 3 and 4, the optical storage medium11has a substrate103, a colored film102, and a reflective film101. The colored film102is formed on the substrate103, and the reflective film101is formed on the colored film102. The substrate103is formed of a transparent resin material such as polycarbonate. As the reflective film101, aluminum is vapor deposited on the substrate103. As the material for the colored film102, copper (II) phthalocyanine is used. The optical storage medium11is bonded to the bottom surface of the recess1c, with the reflective film101facing the bottom surface of the recess1c, with the use of adhesive or the like.

Therefore, the recording beam of laser light60condensed by an object lens54enters the optical storage medium11from the substrate103side, and is condensed on the colored film102, being absorbed thereby. As the colored film102absorbs the condensed information recording laser beam60, it is melted by the laser beam60. As the colored film102is melted, the substrate103, which is in contact with the colored film102, is also heated. As a result, the temperature of the substrate103reaches its glass transition point, at which the substrate103softens. At this temperature, the coloring material in the color film102decomposes, putting pressure on the interface. Consequently, the coloring agent mixes with the substrate material, at the interface, resulting in the formation of a pit at the interface. In other words, an optional number of pits can be formed in a single (in this embodiment) or multiple straight lines in the optical storage medium, by controlling the output of the information recording light power source59while moving the carriage4in the predetermined direction (primary direction); in other words, information can be written into the optical storage medium11. Further, if such a structural arrangement is made that the entirety of the optical portion can be moved with the use of a servomotor or the like in the direction perpendicular to the moving direction of the carriage, information can be recorded in two or more lines in the optical storage medium11, by controlling the position of the carriage4at the end of the movement of the carriage4in the primary direction, corresponding to a single line of recording.

On the other hand, the information display laser light61emitted from the information display light source51is converted into parallel rays, which are transmitted through the half-mirrors58and57, and are reflected (deflected) by the reflective mirror53. Then, the parallel rays are condensed onto the optical storage medium11of the ink container1by the object lens54, and are reflected by the optical storage medium11(reflective film101). After being reflected by the optical storage medium11, the rays are reflected (deflected) by the half-mirrors53and57, being thereby projected onto the light reception sensor52through the collimator lens56.

The pits formed during the recording are lower in refractive index than their adjacencies. Thus, the information encoded, in the form of a line or lines of pits, in the optical storage medium11can be read by detecting the difference in refractive index between the points of the recording area of the optical storage medium11, which have a pit, and those which do not have a pit, while moving the carriage4in the primary scanning direction. Incidentally, as long as it is assured that the difference in refractive index between a point with a pit (which colored film103forms) and a point without a pit is large enough to be detected, it is unnecessary to provide the optical storage medium11with the reflective film101.

Further, the optical portion may be enabled to be moved in entirety in the direction perpendicular to the primary scanning direction, with the use of a servomotor or the like, in the printer, as described above, so that the optical portion can be controlled in position to compensate for the minute deviation in the ink container position, which occurs each time an ink container is mounted. More specifically, the optical portion can be controlled in position by detecting where the pits have been formed in the optical storage medium11, while moving the carriage4in the direction perpendicular to the primary scanning direction by a servomotor after placing the optical portion directly below the optical storage medium11by moving the carriage4.

In the case of the structural arrangement described above, the optical storage medium11and ink container1are made structurally independent from each other. However, they may be structurally integral as will be described next. That is, the optical storage medium11may be an integral part of the ink container proper, or the housing thereof. In such a case, the optical storage medium11is structured as an integral part or the ink container1. This optical storage medium11is the same as that structured as described above. Therefore, the components of the optical storage medium11identical to the counterparts in the above described optical storage medium11will be given the identical referential symbols as those given to the counterparts, one for one, and will not be described at this time.

Referring toFIG. 5, the optical storage medium21is provided with a colored film102and a reflective film101. The colored film102is on the inward side of the colored film102, with respect to the ink container proper1a, and the reflective film101is formed on the colored film102, on the outward side with respect to the ink container proper1a.

More specifically, the colored film102is directly formed on the bottom surface of a recess in the outward surface of the ink container proper1a, and the reflective film101is formed by vapor deposition, on the colored film102, on the outward side with respect to the ink container proper1a. The reflective film101is also made to function as a protective film for protecting the colored film102, which is on the inward side of the reflective film101, with respect to the ink container proper1a.

In this case, a part of the ink container proper1aof the ink container1functions as substrate, like the substrate103of the above described optical storage medium11. Therefore, the ink container proper1ais desired to be formed of a material, such as amorphous cyclic poly olefin, compatible with the material for the colored film102.

The ink container proper1ais also provided with a recess1d, which corresponds in position to the colored film102and reflective film103; the recess1dis provided for the adjustment of the thickness of the wall of the ink container proper1a, across the portion corresponding to the films102and103, so that the portion of the wall of the ink container proper1acorresponding to the films102and103will display roughly the same degree of transparency as that of the substrate103in the above described optical storage medium. Further, the housing1bof this ink container1is provided with an opening1efor allowing a beam of laser light to be projected onto the optical storage medium21.

Not only can information be written into, or read from, the above described optical storage medium11after the mounting of the ink container1into a printer, but also while the ink container1is manufactured.

Next, the information to be recorded in the optical storage medium11will be described. Prior to the mounting of a brand-new ink container into a printer, the information, or the amount of the ink remainder in the ink container, in the optical storage medium11of the brand-new ink container, is a value of the maximum recordable amount of the ink fillable into the ink container, and it is written into the optical storage medium11during ink container manufacture. Incidentally, the so-called amount of ink usage is the sum of the total amount of the ink ejected by the recording head, and the total amount of the ink suctioned away by the recording performance recovery mechanism in order to restore the recording head in recording properties. Thus, the information, or the amount of the ink remaining in the ink container at a given point in time, is obtained by subtracting the amount of ink usage from the information, or the initial amount of the ink in the ink container, in the optical storage medium11. This information can be displayed as the amount of the ink remainder to a user, and is written into the ink container.

By practicing the above described routine, the relationship between the information retained on the main assembly side of a printer, regarding the amount of the ink remainder in an ink container, and the amount of the ink remaining in the ink container having just been mounted as a replacement ink container, can be properly maintained. In other words, even if a partially emptied ink container is removed from the carriage of a printer, and is remounted onto the carriage after the printer is operated with another ink container, the amount of the ink remainder in this partially emptied ink container can be accurately registered on the main assembly side of the printer. This embodiment of the present invention was described with reference to the amount of the ink remainder in an ink container. However, the information to be recorded in the recording medium of an ink container may be the amount of the ink injected into an ink container, amount of the ink consumed from an ink container, etc., because the amount of the ink remainder in an ink container can be calculated from the amount of the ink injected into the ink container during the manufacture of the ink container and the amount of the ink consumed from the ink container.

Further, the information to be recorded in the optical storage medium11of the ink container1may be the date when the ink container was used for the first time. In this case, the date when the ink container, in the brand-new condition, was mounted in a printer for the first time is recorded, as the initial usage date for the ink container11, into the optical storage medium11of the ink container1. Then, each time the ink container1is used, the optical portion10of a printer reads the initial usage date of the ink container1, calculates the number of days having passed since the initial usage date, and subtracts an estimated value equivalent to the amount of the ink reduced by natural evaporation since the initial usage date. Therefore, the amount of the ink remainder displayed on an unshown display panel, monitor, etc., is more accurate.

Generally, ink contains various solvents, which are more than likely to naturally evaporate. Thus, the ratios of the solvents in ink change with the elapse of time, making thereby the recording head2unstable in ejection performance, making thereby it difficult to record an image at a desirable level of quality. In consideration of this fact, an ink container may be structured so that a message can be displayed to a user, suggesting that the ink container in a printer should be replaced with another ink container, when it is determined that the number of days having elapsed since the initial usage date of the ink container in the printer has exceed a predetermined value.

Further, the information to be recorded in the optical storage medium11may be the production date of an ink container. With the production date of a given ink container recorded in the optical storage medium11of the ink container during the production of the ink container, it is possible for the main assembly of a printer to calculate the number of days having elapsed since the manufacture of the ink container, calculate the amount of the ink having reduced due to natural evaporation since the manufacture of the ink container, and subtract the calculated amount of the ink reduction from the information, or the amount of the ink remainder, in the ink container. With this arrangement, the displayed amount of the ink remainder in the ink container is more accurate. Also in this case, the ink container may structured so that a message can be displayed to a user, suggesting that the ink container in a printer should be replaced with another ink container, when it is determined that the number of days having elapsed since the production of the ink container in the printer has exceed a predetermined value.

Moreover, the color of the ink in a given ink container may be recorded in the optical storage medium11. With the color of the ink in a given ink container recorded in the optical storage medium11of the ink container during the production of the ink container, it is possible for the main assembly of a printer to read the information, or the color of the ink in the ink container, in the optical storage medium11, in order to determine whether or not the ink container having just been mounted in the printer is the right one. Therefore, it is possible to prevent ink of the wrong color from being fed into a recording head2.

Next, one of the methods for writing information into an optical storage medium11will be described. Referring toFIG. 6, the optical storage medium11is provided with a data-writable region91into which primary information, such as the amount of the ink remainder in an ink container, described above, is written, and an allocation table-writable region92into which secondary information, that is, the location of the primary information, is written. With this arrangement, when information is added to the primary information which was written in advance in the optical storage medium11, the additional information is written into the regions subsequent to the region into which the primary information was written last time. Therefore, the secondary information, that is, the location of the data-writable region91into which the primary information was written last time, is in the allocation table-writable region92, making it possible to write additional primary information into the location subsequent to the location into which information was written last time. For example, when the end of the content of the main or primary information is blank, that is, no bit is formed there, the primary information is read without the secondary or subordinate information. If the additional information is written to the end of the content, the blank information is not recognized as a piece of information, that is, the blank information is destroyed. According to this embodiment, however, the additional information is written on the basis of the secondary information, the primary information can be written without overwriting the blank information. The position of the end of the information added to the primary information is rewritten to the secondary information, so that the position where the next information is to be written can be recorded. The data writing region91and the allocation table writing region92may be preformed, during manufacturing, as the information of a start positon or the like of the information writing. In this embodiment, the writing method is as described above, but another method is usable.

Referring toFIG. 7(a), the ink container1may be provided with an ink level gauge (which displays amount of ink remainder within range between max. and min. inFIG. 7(a)) for showing the amount of the ink remainder in the ink container1, which is to be printed, or placed by the like method, in advance on the external surface of the ink container1, across the area corresponding to the optical storage medium11. In this case, the pits are formed in the optical storage medium11, in a straight line, the length of which is proportional to the calculated amount of the ink remaining in the ink container, extending from the maximum level mark toward the minimum level mark, as shown inFIG. 7(b), making it possible for a user to visually confirm the calculated amount of the ink in the ink container. Also in this case, when there is no ink left in the ink container, the straight line which the pits form extends from the maximum level mark to the minimum level mark as shown inFIG. 7(c).

A point of the writable region of the optical storage medium11, which has a pit, is different in optical refractive index from a point of the writable region of the optical storage medium11, which does not have a pit. Therefore, a user can see the line. Incidentally, the straight line which the pits form in accordance with the information in the optical storage medium11may be replicated in parallel to make it easier for a user to see the lines, that is, to confirm the amount of the ink remaining in the ink container. With this arrangement, a user can easily confirm the amount of the ink remainder in the ink container even if the ink container1is out of the printer.

In the case of this embodiment of the present invention, the optical storage medium11is in the bottom wall of the ink container1. However, the ink container1may be devised in structure to place the optical storage medium11in the top or side wall of the ink container, in order to make it possible for a user to visually confirm the information in the optical storage medium11while the ink container1is in a printer. The area of the optical storage medium11, across which the information is to be written so that it can be visually confirmed, may be the data-writable region91, or a data-writable region other than the region91. In the case of the latter, the area from which the information is read with the use of a beam of laser light, and the area across which the information is displayed to be visually confirmed by a user, may be independent from each other.

Also in the case of this embodiment, the optical storage medium11is disposed within the recess1cof the ink container1to reduce the possibility that the optical storage medium11will be soiled or damaged due to the accidental touching of the optical storage medium11by a user during the mounting and/or dismounting of the ink container, or the like occasions. Further, the direction in which the ink container1is mounted into the head holder, or onto the carriage4, is perpendicular to the primary scanning direction of the carriage4. Therefore, should the optical storage medium11be accidentally scratched during the mounting or dismounting of the ink container1, the direction in which the scratches extend is likely to be perpendicular to the line, or lines, of the pits, that is, the optical form of the information, formed in the optical storage medium11, and such scratches are not likely to damage a large section, or sections, of the information line, or lines. Therefore, in consideration of the possibility that the ink container1might be accidentally scratched, the information may be written, while being distributed with the use of one of the error correction technologies, for example, the cross interleave read SOLOMON coding, and read thereby, so that the information can be compensated for, for the damaged line, or lines, of the pits. Also in the case of this embodiment, dust and/or the splashes of liquid from the recording head2may adhere to the optical storage medium11, soiling or damaging thereby the recording surface thereof. Thus, in consideration of the reading errors which might occur due to this soiling and/or damaging of the recording surface, the information may be written in entirety across two or more areas so that should it become impossible for the information in one area of the optical storage medium11to be read, the same information in another area can be read in entirety.

Further, the reflective film101of the above described optical storage medium11is an aluminum film formed by vapor deposition, and the materials for the colored film102and substrate103are copper phthalocyanine and polycarbonate, respectively. However, other substances may be chosen as the materials for the optical storage mediums11, as long as an optical storage medium resulting from the chosen materials is the same in properties to the optical storage medium11in this embodiment, in that it changes in optical properties as it is exposed to a beam of light such as laser light.

The optical storage medium11in this embodiment is of a type in which as new information is written into the optical storage medium11, it is to be added to the information therein. However, the optical storage medium11may be structured so that as new information is written into the optical storage medium11, the information therein is replaced by the new information, which is obvious.

In the case of the above described first embodiment of the present invention, the ink container and recording head are structurally independent from each other. However, the recording head may be all integral part of the ink container. The optical storage medium11in this second embodiment is the same in basic structure as that in the above described first embodiment. Therefore, the components of the optical storage medium11in this embodiment identical to the counterparts in the first embodiment will be given the identical referential symbols as those given to the counterparts, one for one, and will not be described at this time.

Referring toFIG. 8, the recording head2of the ink container31in this embodiment is an integral part of the ink container proper1aof the ink container31, remaining therefore connected to the ink container proper1a. Therefore, as the ink container31is replaced by a user, the recording head2is also replaced. Generally speaking, each ink container is different from another ink container in terms of ink ejection properties, for example, amount by which ink is ejected per ejection, speed at which ink is ejected, etc. This difference occurs during ink container manufacture. In consideration of this fact, the information regarding each ink container, in particular, the ink ejection properties of the recording head2, for example, amount by which ink is ejected by the recording head per ejection, speed at which ink is ejected by the recording head2, etc., is desired to be measured and written into the above described optical storage medium11during the manufacture of the ink container, so that as the ink container is mounted into a printer, the information can be read by the printer in order to make its image forming operation reflect the information to improve the level of quality at which an image is formed. With this arrangement, an image much better in quality than that formable by the printer in the preceding embodiment can be formed.

The ink storage portion of the above described ink container1in the first embodiment may be provided with a prism.FIG. 11is a schematic sectional view of the ink container in this embodiment. The optical portion of a printer is disposed so that it does not move in the primary scanning direction of the carriage.FIG. 11(a) shows the relationship between the ink container1and the optical portion10of the printer when the optical storage medium11is directly above the object lens54of the optical portion10(above recording paper), whereasFIG. 11(b) shows the relationship after the carriage has been moved to move the ink container1in order to place the prism39directly above the object lens54.

As the amount of the ink in the ink storage portion reduces, the prism39, with which the ink storage portion is provided, changes in the refractive index of its reflective surfaces, making it possible to optically detect the presence or absence of ink in the ink storage portion.

In the case of this structural arrangement, a single optical system is used to write information into the optical storage medium11, to read the information from the optical storage medium11, and also to detect the amount of the ink remaining in the ink storage portion, that is, to detect the refractive index of the prism39. Therefore, the ink container31is structured so that the vertical (inFIG. 11) distance between the optical storage medium11and the object lens54of the optical portion, becomes different from the vertical distance between a given point of the reflective surfaces of the prism39and the object lens54of the optical portion. Referring toFIG. 11(a), after being condensed by the object lens54, the laser light is focused on the optical storage medium11to write information in the optical storage medium11, or to read the information therefrom. Referring toFIG. 11(b), where the laser light hits the reflective surface of the prism39, the laser light has not completely converged, forming therefore a light spot of a certain size. Therefore, even if a small amount of ink had adhered to the reflective surface of the prism39, the substantial portion of the laser light64is reflected by the reflective surface of the prism39, in spite of the presence of ink spots on the reflective surface, reaching the ink remainder amount detection sensor65, making it therefore possible to detect the presence or absence of ink in the ink storage portion, provided that the size of the light spot formed by the laser light where the laser light hits the reflective surface of the prism39is substantial. In this case, in order to compensate for the errors in the calculated amount of the ink remainder, the methods, in which the total amount of the ink ejected, in the form of an ink droplet, from the recording head2is counted, and the amount of the ink remaining in the ink container1, which is calculated on the main assembly side of an ink jet recording apparatus, based on the counted total amount of the ejected ink, is displayed in the analog fashion, may be combined with the method, in this embodiment, in which the presence or absence of ink in the ink storage portion is detected by providing the ink container1with a prism such as the above described prism39. With such combination, the displayed amount of the ink in the ink container is far more accurate than the amount displayed in the preceding embodiments.

In the case of the above described first and second embodiments of the present invention, the ink container is mounted on the carriage of a printer, being therefore movable within the printer. However, the ink container may be structured so that it is stationarily fixed in a printer.

Providing a printer with an ink container of a large capacity makes it necessary to provide the printer with a carriage capable of holding the ink container of a large capacity, making it therefore necessary to increase the printer in overall size. This dilemma can be eliminated by designing a printer so that an ink container can be made structurally independent from a recording head to make it possible to place an ink container of a large capacity within the printer, at a location other than on the carriage. This design for a printer makes it unnecessary to increase a printer in overall size in order to provide the printer with an ink container of a large capacity, or to reduce, in overall size, a printer employing an ink container of a large size. In the case of this structural arrangement, an ink container is not moved in a printer; the printer is to be provided with a mechanism for moving the optical portion of the printer relative to the optical storage medium of the ink container, so that the information can be written into, or read from, the optical storage medium of the stationary ink container. The mechanism for moving the optical portion of the printer main assembly can be devised so that only a single optical portion is required to write information into, or read information from, each of the optical storage mediums of the multiple ink containers disposed in parallel in the printer main assembly.