Ink supply devices

An ink supply device includes a controller, a cartridge mounting portion, and an ink cartridge. The cartridge mounting portion includes first, second, and third detectors configured to detect first, second, and third detection target portions of the ink cartridge and to output first, second, and third detection information, respectively. The controller is configured to execute a first process if both the first detection information and the second detection information are output and execute a second process if at least one of the first detection information and the second detection information is not output when the third detection information is output during insertion of the ink cartridge into the cartridge mounting portion. It is determined that the ink cartridge has reached a predetermined mount position in the first process, and a type of the ink cartridge is determined in the second process.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Japanese Patent Application No. 2009-080586, which was filed on Mar. 27, 2009, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink supply devices in which a controller is configured to determine a type of an ink cartridge and a position of the ink cartridge based on a detector detecting a portion of the ink cartridge configured to be mounted to a cartridge mounting portion.

2. Description of Related Art

A known inkjet image recording apparatus, such as an inkjet image recording apparatus described in JP-A-2005-288866, has a recording head having a plurality of nozzles formed therein, and a cartridge mounting portion to which an ink cartridge is mounted. The cartridge mounting portion accommodates the ink cartridge removably. When the ink cartridge is mounted to the cartridge mounting portion, an ink path is formed from the ink cartridge via the cartridge mounting portion to the recording head. Through the ink path, ink is supplied from the ink cartridge to the recording head. The recording head selectively ejects ink supplied from the ink cartridge, as small droplets of ink, from the nozzles. The droplets of ink are ejected onto a recording medium, such that an image is recorded thereon.

There are various types of known ink cartridges, each containing ink different in color or volume. In other words, various kinds of known ink cartridges are used with a known image recording apparatus. A known ink cartridge has a detection target portion for the recording apparatus to determine the type of ink cartridge. The detection target portion is positioned at a position corresponding to a detecting device, e.g. an optical detector, which is positioned in the cartridge mounting portion. The detecting device outputs a signal when it detects the detection target portion. The image recording apparatus has a controller configured to determine the type of ink cartridge based on the signal output from the detecting device.

For example, a known image recording apparatus, such as an image recording apparatus described in U.S. Pat. No. 6,739,689B2, is configured to selectively receive three types of ink cartridges. A first-type ink cartridge has a first detection target portion and a second detection target portion, a second-type ink cartridge has the first detection target portion, but does not have the second detection target portion, and a third-type ink cartridge has the second detection target portion, but does not have the first detection target portion. The cartridge mounting portion has two detecting devices configured to detect the first detection target portion and the second detection target portion, respectively. When an ink cartridge is mounted to the cartridge mounting portion, the controller executes a process to determine the type of ink cartridge based on signals output from the two detecting devices.

However, the detection target portions may not be correctly detected. For example, a certain degree of clearance may be provided between the ink cartridge and the cartridge mounting portion to facilitate insertion of the ink cartridge into the cartridge mounting portion. With this clearance, the position of the ink cartridge may change in the cartridge mounting portion, e.g., the ink cartridge may tilt relative to the cartridge mounting portion, and the positional relationship between each of the detection target portions and a corresponding one of the detecting devices may vary. In particular, such variations of the positional relationship are likely to occur in an ink cartridge having a plurality of detection target portions, which are spaced a relatively great distance apart, e.g., which are positioned on top and bottom ends of the ink cartridge when the ink cartridge is mounted to the cartridge mounting portion. Because of the variations, the type of the ink cartridge may not be correctly detected, or a position of the ink cartridge in the cartridge mounting portion may not be correctly determined.

For example, when the first-type ink cartridge having the first detection target portion and the second detection target portion is mounted to the cartridge mounting portion while being tilted relative to the cartridge mounting portion, the first detection target portion may be detected while the second detection target portion may not be detected. In this case, the controller may incorrectly determine that the second-type ink cartridge that has the first detection target portion, but does not have the second detection target portion, is mounted to the cartridge mounting portion. If printing is carried out with the ink cartridge whose type is incorrectly determined by the controller, a different type of ink may mix with ink remaining in the nozzles of the recording head, resulting in an undesired chemical reaction that may cause mixed ink to solidify in the nozzles.

In addition, the detection target portions of the ink cartridge may be broken off when the ink cartridge is accidentally bumped or dropped. If the first-type ink cartridge with the second detection target portion broken off is mounted to the cartridge mounting portion, the controller may incorrectly determine that the second-type ink cartridge is mounted to the cartridge mounting portion.

On a different note, when the image recording apparatus is turned off with the ink cartridge mounted to the cartridge mounting portion, a record on determination as to whether the ink cartridge is mounted may be lost from storage device, e.g. memory. In this case, even when the apparatus is turned on again with the ink cartridge mounted to the cartridge mounting portion, whether the ink cartridge is mounted to the cartridge mounting portion may need to be determined.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for ink supply devices which overcome these and other shortcomings of the related art. A technical advantage of the present invention is that a type of an ink cartridge is determined and it is determined that the ink cartridge is in a mount position in a cartridge mounting portion, based on a detector detecting a detection target portion of the ink cartridge. Another independent technical advantage of the present invention is that chances that an ink cartridge with a detection target portion broken off is used in an ink supply device are reduced. Another independent technical advantage of the present invention is that it is determined that an ink cartridge is in a mount position in a cartridge mounting portion is determined even after an ink supply device is turned off and then turned on again with the ink cartridge mounted to a cartridge mounting portion of the ink supply device. These technical advantages are independent of each other, and at least one of the technical advantages may be achieved by the present invention.

According to an embodiment of the present invention, an ink supply device comprises a controller, a cartridge mounting portion, and an ink cartridge configured to be mounted to the cartridge mounting portion by being inserted thereinto in a insertion direction. The ink cartridge comprises a first detection target portion positioned at an upper front side of the ink cartridge during an insertion of the ink cartridge into the cartridge mounting portion in the insertion direction, a second detection target portion positioned at a lower front side of the ink cartridge during the insertion of the ink cartridge into the cartridge mounting portion in the insertion direction, and a third detection target portion positioned at a front side of the ink cartridge during the insertion of the ink cartridge into the cartridge mounting portion in the insertion direction, wherein the third detection target portion is positioned between the first detection target portion and the second detection target portion. The cartridge mounting portion comprises a first detector configured to detect the first detection target portion and to output first detection information when the first detector detects the first detection target portion, a second detector configured to detect the second detection target portion and to output second detection information when the second detector detects the second detection target portion, and a third detector configured to detect the third detection target portion and to output third detection information when the third detector detects the third detection target portion. The controller is configured to execute a first process if both the first detection information and the second detection information are output and execute a second process if at least one of the first detection information and the second detection information is not output when the third detection information is output during the insertion of the ink cartridge into the cartridge mounting portion. It is determined that the ink cartridge has reached a predetermined mount position in the first process, and a type of the ink cartridge is determined in the second process.

Other objects, features, and advantages will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention, and their features and advantages, may be understood by referring toFIGS. 1-17, like numerals being used for like corresponding parts in the various drawings.

Referring toFIG. 1, a printer12is a color inkjet printer configured to record an image on a recording medium, e.g., a sheet of paper (hereinafter referred to as a recording sheet), by selectively ejecting ink of each color as ink droplets from a recording head21. Ink is supplied to the recording head21from an ink cartridge30. In this embodiment, the ink cartridge30stores ink of cyan (C), magenta (M), yellow (Y), or black (K). In other words, the printer12uses four ink cartridges30storing ink of different colors respectively.

The ink cartridge30and the recording head21are coupled with each other via an ink tube20. There are four ink tubes20in accordance with four ink colors. Ink of each color stored in each ink cartridge30is supplied to recording head via a corresponding ink tube20.

The printer12comprises a sheet supply tray15that holds a stack of recording sheets. Each recording sheet is picked up by a pick up roller23and conveyed to a sheet conveying path24. In the sheet feed path24, a pair of conveying rollers25conveys the recording sheet onto a platen26. The recording head21selectively ejects ink droplets of each color onto the recording sheet passing over the platen26, such that an image is recorded on the recording sheet. A pair of ejection rollers22ejects the recording medium passing over the platen26to an output tray16.

The printer12comprises an ink supply device100comprising the four ink cartridges30storing ink of the above-described colors and a cartridge holder110. There are three types of ink cartridge30storing the same color ink, but storing different amounts of ink. The three types of ink cartridge30are identical in structure except for structures of ribs77A,77B,80A, and80B. Thus, the following description will be made based on one type of ink cartridge30.

Referring toFIGS. 2A and 2B, the ink cartridge30has substantially a rectangular parallelepiped shape or box shape. A width of ink cartridge30in a width direction as indicated by an arrow51is relatively short, and each of a height of ink cartridge30in a height direction as indicated by an arrow52and a depth of ink cartridge30in a depth direction as indicated by an arrow53is greater than the width of ink cartridge30. The ink cartridge30is inserted into the cartridge holder110in a direction as indicated by an arrow50(hereinafter referred to as an insertion direction50), being in the position (posture) shown inFIG. 2A. The insertion direction50is parallel to the depth direction53. The ink cartridge30comprises a front wall40facing forward with respect to the insertion direction50.

The ink cartridge30comprises an ink chamber36formed therein. The ink chambers36of the four ink cartridges30store cyan ink, magenta ink, yellow ink, and black ink, respectively.

The ink cartridge30is made of a translucent material, e.g., a transparent or semi-transparent material, so that light, e.g., visible or infrared light can pass through the ink cartridge30. A first protruding member75and a second protruding member76protrude from the front wall40in the insertion direction50.

The ink cartridge30comprises an ink amount detection portion34. Through the ink amount detection portion34, the amount of ink stored in the ink chamber36is visually or optically detected. The ink amount detection portion34has a substantially rectangular parallelepiped shape that is thin in the width direction51. The ink amount detection portion34is integrally formed with the front wall40of the ink cartridge30. The ink amount detection portion34protrudes outward (rightward inFIG. 2B) from a middle portion of the front wall40with respect to the height direction52. The ink amount detection portion34is smaller in width than the front wall40in the width direction51. A width of the ink amount detection portion34is set, such that the ink amount detection portion34can enter a detection area115of an optical detector114(FIG. 6). The ink amount detection portion34is formed of a translucent material through which light can pass in the width direction51.

Referring toFIG. 2B, the ink amount detection portion34has an inner space35formed therein. The inner space35communicates with the ink chamber36. The inner space35of the ink amount detection portion34is defined by walls of the ink amount detection portion34, i.e., a bottom wall34A, sidewalls34B, a top wall34D, and a front wall34E. A light blocking plate62of a detection arm60is positioned in the inner space35. The optical detector114emits light, e.g., visible or infrared light toward an irradiated portion34C positioned at a lower portion of the sidewalls34B of the ink amount detection portion34.

The detection arm60is positioned in the ink chamber36. The detection arm60comprises the light blocking plate62, an arm body63, and a float64. The detection arm60is configured to move, according to the amount of ink stored in the ink chamber36, between a position where the light blocking plate62contacts the bottom wall34A of the ink amount detection portion34(hereinafter referred to as a lower position) and a position where the light blocking plate62is separated from the bottom wall34A and contacts the top wall34D (hereinafter referred to as an upper position). InFIG. 2B, the detection arm60positioned in the lower position is indicated by a solid line, and the detection arm60positioned in the upper position is indicated by a broken line. Because the position of the light blocking plate62in the ink amount detection portion34can be seen visually, a user can recognize the amount of ink stored in the ink chamber36. In addition, when the optical detector114detects the position of the light blocking plate62in the ink amount detection portion34, a controller90can determine the amount of ink in the ink chamber36.

The arm body63is an elongated rod-shaped member, and is pivotally supported by a shaft66extending between both sidewalls41of the ink cartridge30in the width direction51. The arm body63is pivotable in the ink chamber36in directions indicated by arrows67and68.

The float64is positioned at an end of the arm body63with respect to a removal direction54opposite to the insertion direction50. The float64has a hollow interior formed therein, and a predetermined buoyancy acts on the float64when the float64is submerged in ink. Thus, the float64moves in the height direction52when the amount of ink stored in the ink chamber36increases or decreases. When the float64moves, the detection arm60pivots about the shaft66. In another embodiment, the float64may not have a hollow interior therein, and a portion of the arm body63extending from the supporting shaft66to the float64and the float64may have the specific gravity less than the specific gravity of ink, such that a predetermined buoyancy acts thereon, or a portion of the portion of the arm body63extending from the supporting shaft66to the float64and the float64may have the specific gravity less than the specific gravity of ink, such that a predetermined buoyancy acts thereon.

The light-blocking panel62is positioned at an end of the arm body63with respect to the insertion direction50, i.e., at an end opposite from the float64. When the ink amount in the ink chamber36is greater than or equal to a predetermined amount, the detection arm60pivots clockwise, i.e., the direction indicated by the arrow67, inFIG. 2Babout the shaft66because of the buoyancy acting on the float64, and the light-blocking panel62moves downward in the inner space35. Then, the light-blocking panel62comes into contact with the bottom wall34A of the ink amount detection portion34and remains in the lower position (the position indicated by the solid line inFIG. 2B). When the ink amount in the ink chamber36is reduced to the predetermined amount, a part of the float64is exposed from the ink surface, and the buoyancy is balanced out by the gravity. When the ink amount in the ink chamber36is further reduced to an amount less than the predetermined amount, the float64moves down as the ink surface in the ink chamber36is lowered. When this occurs, the detection arm60pivots counterclockwise i.e., the direction indicated by the arrow68, inFIG. 2Babout the shaft66, and the light-blocking panel62moves upward in the inner space35and moves apart from the bottom wall34A. Then, the light-blocking panel62comes into contact with the top wall34D and remains in the upper position (the position indicated by the broken line inFIG. 2B).

The light-blocking panel62is aligned with the irradiated portion34C in the width direction51when the light-blocking panel62is in the lower position. In contrast, when the light-blocking panel62is in the upper position, the light-blocking panel62is positioned above the irradiated portion34C, and is not aligned with the irradiated portion34C in the width direction51.

The ink cartridge30comprises an air communication opening71and an ink supply portion72at the front wall40. The air communication opening71is positioned above the ink amount detection portion34at the front wall40. The air communication opening71is formed through the front wall40and provides communication between an exterior of the ink cartridge30and the ink chamber36. The air communication opening71allows air to be introduced from the exterior of the ink cartridge30to the ink chamber36. When the ink cartridge30is in an unused state (for example, when the ink cartridge30is shipped from a factory), the air communication opening71is sealed with a sticker or the like from the outside. Therefore, if the ink chamber36is depressurized for example, the depressurized state is maintained. When the ink cartridge30is used, the sticker is torn or removed, and hence the ink chamber36is brought into an atmospheric pressure.

The ink supply portion72is positioned below the ink amount detection portion34. The ink supply portion72is formed of a tubular member having elasticity and protrudes outward, or in the insertion direction50, from the front wall40. The ink supply portion72has a through hole73formed through the center thereof. Ink in the ink chamber36is supplied to the exterior of the ink cartridge30via the through hole73.

The ink cartridge30comprises a rib43extending in the depth direction53. The rib43protrudes upward from a top wall39of the ink cartridge30. An engaging surface45of the rib43is positioned apart from the front wall40in the removal direction54, and is positioned at about a middle portion of the top wall39in the depth direction53.

The ink cartridge30comprises the first protruding member75and the second protruding member76. The ink cartridges30are classified according to the initial amount of ink stored in the ink chamber36. In this embodiment, the ink cartridges30are classified into “high-capacity ink cartridge30”, “standard-capacity ink cartridge30” and “low-capacity ink cartridge30.” The initial amount of ink stored in the ink chamber36of the high-capacity ink cartridge30is greater than the initial amount of ink stored in the ink chamber36of the standard-capacity ink cartridge30, and the initial amount of ink stored in the ink chamber36of the standard-capacity ink cartridge30is greater than the initial amount of ink stored in the ink chamber36of the low-capacity ink cartridge30. The first protruding member75comprises a rib77A or77B, and the second protruding member76comprises a rib80A or80B. The structures of the first and second protruding members75and76, i.e., whether the first protruding member75comprises the rib77A or77band whether the second protruding member76comprises the rib80A or80B, are different according to the types of ink cartridge30.FIG. 2illustrates the high-capacity ink cartridge30.

The first protruding member75is integrally formed with the rib43at an upper end of the front wall40. A width of the first protruding member75is the same as the width of the front wall40in the width direction51, and the first protruding member75protrudes from the front wall40in the insertion direction50. In the insertion direction50, an end75A of the first protruding member75is positioned further forward than an end of the ink supply portion72. In other words, a dimension of the first protruding member75protruding from the front wall40in the insertion direction50is greater than a dimension of the ink supply portion72protruding from the front wall40in the insertion direction50. In the insertion direction50, the end75A of the first protruding member75is positioned further forward than ends of the ink amount detection portion34and a triggering portion85. In other words, the dimension of the first protruding member75protruding from the front wall40in the insertion direction50is greater than dimensions of the ink amount detection portion34and the triggering portion85protruding from the front wall40in the insertion direction50.

Referring toFIGS. 3A,4A, and5A, the first protruding member75has a recess79formed in its lower surface78. The recess79is substantially rectangular in cross section taken along the width direction51and the height direction52, and is open downward. The recess79extends along the depth direction53from the end75A of the first protruding member75in the depth direction53. The recess79is defined by a surface extending parallel to the width direction51and the depth direction53, two surfaces extending parallel to the height direction52and the depth direction53, and a surface extending parallel to the width direction51and the height direction52.

Referring toFIG. 3A, the rib77A extends in the height direction52in the recess79. The rib77A extends up to substantially the same height as the lower surface78from the surface defining the recess79and extending parallel to the width direction51and the depth direction53. The rib77A extends in the depth direction53. The rib77A is positioned at a middle portion of the recess79in the width direction51. The rib77A is formed in the high-capacity ink cartridge30, and extends from the end75A of the first protruding member75in the depth direction53to an end of the recess79in the removal direction54, i.e., to the surface defining the recess79and extending parallel to the width direction51and the height direction52. In other words, the rib77A extends over the entire length of the recess79in the depth direction53. A width of the rib77A is set, such that the rib77A can enter a detection area109of an optical detector107(FIG. 6). The rib77A is formed of an opaque material configured to block light emitted from the optical detector107.

Referring toFIGS. 4A and 5A, the first protruding member75of the standard-capacity ink cartridge30and the low-capacity ink cartridge30comprises a rib77B extending in the height direction52in the recess79. The rib77B extends up to substantially the same height as the lower surface78of the first protruding member75from the surface defining the recess79and extending parallel to the width direction51and the depth direction53. The rib77B extends in the depth direction53. The rib77B is positioned at a middle portion of the recess79in the width direction51. The rib77B is formed in the standard-capacity ink cartridge30and the low-capacity ink cartridges30, and extends from a predetermined position in the depth direction53to the end of the recess79in the removal direction54, i.e., to the surface defining the recess79and extending parallel to the width direction51and the height direction52. The predetermined position is offset from the end75A of the first protruding member75in the removal direction54. The predetermined position is offset in the removal direction54from a line extending in the height direction52passing through an end of the triggering portion85. That is, the rib77B does not exist directly above the triggering portion85with respect to the height direction52. In other words, the rib77B does not reach the end75A of the first protruding member75, and is shorter than the recess79in the depth direction53. A width of the rib77B is set, such that the rib77B can enter the detection area109of the optical detector107(FIG. 6). The rib77B is formed of an opaque material configured to block light emitted from the optical detector107.

The second protruding member76is positioned at a lower end of the front wall40. A width of the second protruding member76is the same as the width of the front wall40in the width direction51. The second protruding member76protrudes from the front wall40in the insertion direction50. In the insertion direction50, an end76A of the second protruding member76is positioned further forward than the end of the ink supply portion72. In other words, a dimension of the second protruding member76protruding from the front wall40in the insertion direction50is greater than the dimension of the ink supply portion72protruding from the front wall40in the insertion direction50. In the insertion direction50, the end76A of the second protruding member76is positioned further forward than the ends of the ink amount detection portion34and the triggering portion85. In other words, the dimension of the second protruding member76protruding from the front wall40in the insertion direction50is greater than the dimensions of the ink amount detection portion34and the triggering portion85protruding from the front wall40in the insertion direction50.

Referring toFIGS. 3B,4B, and5B, the second protruding member76has a recess82formed in its upper surface81. The recess82is substantially rectangular in cross section taken along the width direction51and the height direction52, and is open upward. The recess82extends along the depth direction53from the end76A of the second protruding member76in the depth direction53. The recess82is defined by a surface extending parallel to the width direction51and the depth direction53, two surfaces extending parallel to the height direction52and the depth direction53, and a surface extending parallel to the width direction51and the height direction52.

Referring toFIG. 4B, the rib80A extends in the height direction52in the recess82. The rib80A extends up to substantially the same height as the upper surface81from the surface defining the recess82and extending parallel to the width direction51and the depth direction53. The rib80A extends in the depth direction53. The rib80A is positioned at a middle portion of the recess82in the width direction51. The rib80A is formed in the standard-capacity ink cartridge30, and extends from the end76A of the second protruding member76in the depth direction53to an end of the recess82in the removal direction54, i.e., to the surface defining the recess82and extending parallel to the width direction51and the height direction52. In other words, the rib80A extends over the entire length of the recess82in the depth direction53. A width of the rib80A is set, such that the rib80A can enter a detection area120of an optical detector118(FIG. 6). The rib80A is formed of an opaque material configured to block light emitted from the optical detector118.

Referring toFIGS. 3B and 5B, the second protruding member76for the high-capacity ink cartridge30and the low-capacity ink cartridges30comprises a rib80B extending in the height direction52in the recess82. The rib80B extends up to substantially the same height as the upper surface81of the second protruding member76from the surface defining the recess82and extending parallel to the width direction51and the depth direction53. The rib80B extends in the depth direction53. The rib80B is positioned at a middle portion of the recess82in the width direction51. The rib80B is formed in the high-capacity ink cartridge30and the low-capacity ink cartridge30, and extends from a predetermined position, in the depth direction53to the end of the recess82in the removal direction54, i.e., to the surface defining the recess82and extending parallel to the width direction51and the height direction52. The predetermined position is offset in the removal direction54from a line extending in the height direction52passing through an end of the triggering portion85. That is, the rib80B does not exist directly below the triggering portion85with respect to the height direction52. In other words, the rib80B does not reach the end76A of the second protruding member76, and is shorter than the recess82in the depth direction53. A width of the rib80B is set, such that the rib80B can enter the detection area120of the optical detector118(FIG. 6). The rib80B is formed of an opaque material configured to block light emitted from the optical detector118.

Referring toFIGS. 2A and 2B, the ink cartridge30comprises the triggering portion85. The triggering portion85is spaced apart from the ink amount detection portion34in the insertion direction50. That is, the triggering portion85and the ink amount detection portion34are positioned, such that the triggering portion85is positioned further forward than the ink amount detection portion34in the insertion direction50, and a space86is formed between the triggering portion85and the ink amount detection portion34in the insertion direction50.

The triggering portion85is connected to the bottom wall34A and the top wall34D of the ink amount detection portion34via a wall extending between the triggering portion85and the bottom wall34and a wall extending between the triggering portion85and the top wall34D, respectively. A width of the triggering portion85is substantially the same as the width of the ink amount detection portion34in the width direction51, and is set, such that the triggering portion85can enter the detection area115of the optical detector114(FIG. 6). The triggering portion85is formed of an opaque material such that light is not allowed to pass therethrough in the width direction51. Light can pass in the width direction51through the space86formed between the triggering portion85and the ink amount detection portion34. The space86is defined at the same height as the irradiated portion34C of the ink amount detection portion34. In addition, the end of the triggering portion85in the insertion direction50is offset from each end75A,76A of the first and second protruding members75and76in the removal direction54. In other words, the dimension of the triggering portion85protruding from the front wall40in the insertion direction50is less than the dimension of each of the first and second protruding members75and76protruding from the front wall40in the insertion direction50.

Referring toFIG. 6, the cartridge holder110is configured to accommodate the ink cartridges30in the interior thereof. The cartridge holder110has an opening112at the front side of the printer12(left side inFIG. 6). The ink cartridges30are inserted into the cartridge holder110through the opening112. A direction in which the ink cartridge30is inserted into the cartridge holder110is referred to as the insertion direction50, the direction in which the ink cartridge30is removed from the cartridge holder110is referred to as the removal direction54, and the directions along the insertion direction50and the removal direction54is referred to as insertion/removal directions105. The cartridge holder110allows the four ink cartridges30to be mounted thereto. Although a structure of the cartridge holder110for one of the ink cartridges30to be mounted to the cartridge holder110is described below, the structure described below is provided for each of the ink cartridges30to be mounted to the cartridge holder110. In other words, in the cartridge holder110, the respective components described below are provided on the cartridge holder110corresponding to the four ink cartridges30storing respective color inks.

Referring toFIG. 6, the cartridge holder110includes an end wall117opposite the opening112. The optical detector114is positioned at a substantially middle portion of the end wall117with respect to the height direction52. The optical detector114protrudes from the end wall117toward the opening112along the insertion/removal direction105. The optical detector114is configured to selectively detect the light-blocking plate62positioned in the ink amount detection portion34and the triggering portion85of the ink cartridge30. Thus, the optical detector114is positioned at the same height as the ink amount detection portion34and the triggering portion85of the ink cartridge30to be mounted in the cartridge holder110. The triggering portion85and the ink amount detection portion34of the ink cartridge30enter the detection area115of the optical detector114in this order during the insertion of the ink cartridge30into the cartridge holder110.

The optical detector114is a transmissive photo-interrupter comprising a light emitting portion (not shown) configured to emit light, e.g., visible light or infrared light, and a light receiving portion (not shown) configured to receive light emitted from the light emitting portion. The light emitting portion comprises a light emitting diode, and the light receiving portion comprises a photo transistor. The light emitting portion and the light receiving portion are positioned so as to face each other in the width direction51, and an optical path extending from the light emitting portion to the light receiving portion corresponds to the detection area115. When the light blocking plate62positioned in the ink amount detection portion34or the triggering portion85enters the detection area115and blocks the light in the detection area115, i.e., when the light blocking plate62positioned in the ink amount detection portion34or the triggering portion85is detected by the optical detector114, the intensity of light received by the light receiving portion changes, which causes a signal output from the optical detector114to change. The signal output from the optical detector114is sent to the controller90(FIG. 7).

Referring toFIG. 6, the optical detector107is positioned in an upper portion of the end wall117of the cartridge holder110. An opening108is formed through the upper portion of the end wall117. The opening108is formed through the end wall117in the insertion/removal direction105. The opening108has a width and a height which are greater than those of the first protruding member75of the ink cartridge30. Thus, the first protruding member75is allowed to pass through the opening108and protrude from the end wall117in the insertion direction50.

The optical detector107extends through the opening108toward the opening112. The optical detector107is configured to selectively detect the rib77A and77B of the first protruding member75of the ink cartridge30. The rib77A and77B selectively enter the detection area109of the optical detector107during the insertion of the ink cartridge30into the cartridge holder110.

Similarly to the optical detector114, the optical detector107is a transmissive photo-interrupter comprising a light emitting portion (not shown) configured to emit light, e.g., visible light or infrared light, and a light receiving portion (not shown) configured to receive light emitted from the light emitting portion. In the optical detector107, an optical path extending from the light emitting portion to the light receiving portion corresponds to the detection area109. When the rib77A or77B enters the detection area109and blocks the light in the detection area109, i.e., when the rib77A or77B is detected by the optical detector107, the intensity of light received by the light receiving portion changes, which causes a signal output from the optical detector107to change. The signal output from the optical detector107is sent to the controller90(FIG. 7).

Referring toFIG. 6, the optical detector118is positioned in a lower portion of the end wall117of the cartridge holder110. An opening119is formed through the lower portion of the end wall117. The opening119is formed through the end wall117in the insertion/removal direction105. The opening119has a width and a height which are greater than those of the second protruding member76of the ink cartridge30. Thus, the second protruding member76is allowed to pass through the opening119and protrude from the end wall117in the insertion direction50.

The optical detector118extends through the opening119toward the opening112. The optical detector118is configured to selectively detect the rib80A and80B of the second protruding member76of the ink cartridge30. The rib80A and80B selectively enter the detection area120of the optical detector118during the insertion of the ink cartridge30into the cartridge holder110.

Similarly to the optical detector114, the optical detector118is a transmissive photo-interrupter comprising a light emitting portion (not shown) configured to emit light, e.g., visible light or infrared light, and a light receiving portion (not shown) configured to receive light emitted from the light emitting portion. In the optical detector118, an optical path extending from the light emitting portion to the light receiving portion corresponds to the detection area120. When the rib80A or80B enters the detection area120and blocks the light in the detection area120, i.e., when the rib80A or80B is detected by the optical detector118, the intensity of light received by the light receiving portion changes, which causes a signal output from the optical detector118to change. The signal output from the optical detector118is sent to the controller90(FIG. 7).

Referring toFIG. 6, the cartridge holder110comprises a lock mechanism144. The lock mechanism144is configured to place the ink cartridge30in a mount position in the cartridge holder110and prevent the ink cartridge30from moving in the removal direction54. The ink cartridge30is retained in the mount position in the cartridge holder110. When the ink cartridge30is in the mount position, ink is allowed to be supplied from the ink chamber36to the recording head21via the cartridge holder110.

The lock mechanism144is positioned in an upper portion of the cartridge holder110adjacent to the opening112. The lock mechanism144comprises a lock lever145and a coil spring148. The lock lever145is supported by a support shaft (not shown) and is configured to move between an unlock position illustrated inFIGS. 8A and 8Band a lock position illustrated inFIG. 6. The coil spring148is configured to urge the lock lever145toward the lock position. An end of the lock lever145facing the insertion direction50is an engaging end146. The engaging end146is configured to contact the engaging surface45of the ink cartridge30, such that the ink cartridge30is prevented from moving in the removal direction54, i.e., the ink cartridge30is locked in the mount position.

The lock lever145comprises an operating portion147at an end opposite to the engaging end146. When the operating portion147is lowered, the lock lever145in the lock position is moved to the unlock position against an urging force of the coil spring148. In this state, the ink cartridge30can be removed from the cartridge holder110.

Referring toFIG. 6, an opening113is formed through the lower portion of the end wall117from the inner surface of the end wall117to the outer surface of the end wall117. A connecting portion121and an ink supply tube122are provided at the inner surface of the end wall117so as to be in fluid communication with the opening113. The flexible ink tube20(seeFIG. 1) is connected to the outer surface of the end wall117so as to be in fluid communication with the opening113. When the ink cartridge30is mounted to the cartridge holder110in the mount position, the ink supply tube122is inserted into the through hole73of the ink supply portion72. Accordingly, an ink path extending from the ink chamber36of the ink cartridge30via the through hole73of the ink supply portion72and the ink supply tube122to the connecting portion121is formed, and the ink stored in the ink chamber36is supplied to the recording head21via the ink tube20.

A rod124is provided at the upper portion of the end wall117. The rod124projects from the end wall117toward the opening112in the removal direction54. When the ink cartridge30is mounted to the cartridge holder110, the rod124is inserted into the air communication opening71. Accordingly, a seal member which has sealed the air communication opening71is torn, and the ink chamber36is brought into fluid communication with the atmosphere.

Referring toFIG. 7, the controller90is configured to execute a first process based on the signals output from the optical detectors107and118and execute a second process based on the signals output from the optical detectors107and118when the triggering portion85is detected by the optical detector114during the insertion of the ink cartridge30into the cartridge holder110. It is determined that the ink cartridge30has reached the mount position in the first process, and the type of the ink cartridge30is determined among the high-capacity ink cartridge30, the standard-capacity ink cartridge30, and the low-capacity ink cartridge30in the second process.

In this embodiment, the controller90is configured to control the entire operation of the printer12. Nevertheless, because configurations relating to control of the recording head21and the pickup roller23etc. do not relate directly to the present invention, detailed description thereof is omitted.

Referring toFIG. 7, the controller90is configured as a microcomputer comprising a central processing unit (CPU)91, read-only memory (ROM)92, random access memory (RAM)93, erasable programmable read only memory (EEPROM)94, and an application-specific integrated circuit (ASIC)95.

The ROM92stores programs for the CPU91to control various operations of the printer12, programs for the CPU91to execute the first process and the second process, and a table of one-to-one correspondence between the types of ink cartridge30and output signals of the optical detectors107and118. The RAM93is used as a storage area for temporality storing data or signals or a work area for the data processing for the CPU91to execute the programs described above. The EEPROM94stores settings, flags, and the like which are to be retained even after the printer12is turned OFF.

The CPU91, the ROM92, the RAM93, and the EEPROM94are electrically connected to the ASIC95via a bus97so as to be capable of communicating with each other. The optical detectors107,114,118are electrically connected to the ASIC95, such that the optical detectors107,114,118can output signals to the ASIC95.

Each optical detector107,114,118is configured to output an analog electric signal, e.g. a voltage or current signal, corresponding to the intensity of light received by the light receiving portion. When the electrical level, e.g. a voltage or current value of the signal output from the optical detector107,114, or118, is greater than or equal to a predetermined threshold value, the controller90determines that the signal is as a HI level signal, and when the electrical level is less than the predetermined threshold value, the controller90determines that the signal is a LOW level signal. In the embodiment, the signal output from each optical detector107,114,118is determined as the LOW level signal when the light emitted from the light emitting portion is blocked in the detection area109,115,120, and determined as the HI level signal when the light is not blocked. In this embodiment, the LOW level signal output from the optical detector107corresponds to first detection information, the LOW level signal output from the optical detector118corresponds to second detection information, and the LOW level signal output from the optical detector114corresponds to third detection information.

Referring toFIG. 8A, when the high-capacity ink cartridge30is inserted into the cartridge holder110in the insertion direction50, the first protruding member75contacts the engaging end146of the lock lever145. When this occurs, the lock lever145rotates counterclockwise, the engaging end146moves upward, and the position of the lock lever145changes from the lock position to the unlock position.

Referring toFIG. 8B, when the ink cartridge30is further inserted in the insertion direction50, the triggering portion85enters the detection area115of the optical detector114, and then the signal output from the optical detector114changes from the HI level signal to the LOW level signal (T1inFIG. 14). In other words, the controller90determines that the optical detector114detects the triggering portion85(S1: Yes inFIG. 17).

When the controller90determines that the optical detector114detects the triggering portion85, it executes the second process in which the type of the ink cartridge30is determined (S2inFIG. 17). In the high-capacity ink cartridge30, the first protruding member75comprises the rib77A, and the second protruding member76comprises the rib80B. Thus, when the controller90determines that the optical detector114detects the triggering portion85, the rib77A is in the detection area109of the optical detector107and the rib80B is not in the detection area120of the optical detector118. In other words, when the controller90determines that the optical detector114detects the triggering portion85, the signal output from the optical detector107has changed from the HI level signal to the LOW level signal and the signal output from the optical detector118remains unchanged as the HI level signal (T1inFIG. 14). The controller90checks the output signals of the optical detectors107,118, i.e., the combination of (LOW, HI), in the table stored in the ROM92, to determine the type of ink cartridge30inserted into the cartridge holder110. In this example, the controller90determines that the ink cartridge30inserted into the cartridge holder110is the high-capacity ink cartridge30.

When the ink cartridge30is further inserted in the insertion direction50, the triggering portion85passes over the detection area115of the optical detector114. At this time, the signal output from the optical detector114changes from the LOW level signal to the HI level signal (FIG. 14).

Referring toFIG. 9, when the ink cartridge30is inserted all the way into the cartridge holder110and reaches the mount position, the rib80B enters the detection area120of the optical detector118. At this time, the output signals of the optical detectors107and118are both the LOW level signals (T2inFIG. 14). When the output signals of the optical detectors107and118are both the LOW level signals (S3: Yes inFIG. 17), the controller90executes the first process, i.e., the controller90determines that the ink cartridge30has reached the mount position (S4inFIG. 17).

When the ink cartridge30has reached the mount position, the irradiation portion34C of the ink amount detection portion34has already entered the detection area115of the optical detector114. When the ink cartridge30is new or unused, it stores the predetermined amount or more of ink in the ink chamber36and the light blocking plate62of the detection arm60is positioned in the lower position and blocks the light in the detection area115. Thus, the signal output from the optical detector114has changed from the HI level signal to the LOW level signal.

When the ink cartridge30reaches the mount position, the engaging surface45of the rib43passes over the engaging end146of the lock lever145. When this occurs, because the engaging end146of the lock lever145is not supported by the rib43, the lock lever145in the unlock position rotates to the lock position by the urging force of the coil spring148, and the engaging end146of the lock lever145contacts the engaging surface45of the rib43, such that the ink cartridge30is locked in the removal direction54and retained in the mount position.

As described above, when the ink cartridge30is mounted in the cartridge holder110, the ink supply tube122is inserted into the through hole73of the ink supply portion72, and ink stored in the ink chamber36is supplied to the recording head21via the ink tube20. The rod124is inserted into the air communication opening71and the ink chamber36is in communication with the atmosphere.

When ink is supplied from the ink cartridge30mounted in the cartridge holder110and then the amount of ink remaining in the ink chamber36becomes less than the predetermined amount, the light blocking plate62of the detection arm60moves from the lower position to the upper position. Accordingly, the output signal of the optical detector114changes from the LOW level signal to the HI level signal, and the controller90determines that the amount of ink remaining in the ink chamber36becomes low.

Referring toFIG. 10A, when the standard-capacity ink cartridge30is inserted into the cartridge holder110in the insertion direction50, the first protruding member75contacts the engaging end146of the lock lever145. When this occurs, the lock lever145rotates counterclockwise, the engaging end146moves upward, and the position of the lock lever145changes from the lock position to the unlock position.

Referring toFIG. 10B, when the ink cartridge30is further inserted in the insertion direction50, the triggering portion85enters the detection portion115of the optical detector114, and then the signal output from the optical detector114changes from the HI level signal to the LOW level signal (T3inFIG. 15). In other words, the controller90determines that the optical detector114detects the triggering portion85(S1: Yes inFIG. 17).

When the controller90determines that the optical detector114detects the triggering portion85, it executes the second process in which the type of the ink cartridge30is determined (S2inFIG. 17). In the standard-capacity ink cartridge30, the first protruding member75comprises the rib77B, and the second protruding member76comprises the rib80A. Thus, when the controller90determines that the optical detector114detects the triggering portion85, the rib77B is not in the detection area109of the optical detector107and the rib80A is in the detection area120of the optical detector118. In other words, when the controller90determines that the optical detector114detects the triggering portion85, the signal output from the optical detector107remains unchanged as the HI level signal and the signal output from the optical detector118has changed from the HI level signal to the LOW level signal (T3inFIG. 15). The controller90checks the output signals of the optical detectors107,118, i.e., the combination of (HI, LOW), in the table stored in the ROM92, to determine the type of ink cartridge30inserted into the cartridge holder110. In this example, the controller90determines that the ink cartridge30inserted into the cartridge holder110is the standard-capacity ink cartridge30.

When the ink cartridge30is further inserted in the insertion direction50, the triggering portion85passes over the detection area115of the optical detector114. At this time, the signal output from the optical detector114changes from the LOW level signal to the HI level signal (FIG. 15).

Referring toFIG. 11, when the ink cartridge30is inserted all the way into the cartridge holder110and reaches the mount position, the rib77B enters the detection area109of the optical detector107. At this time, the output signals of the optical detectors107and118are both the LOW level signals (T4inFIG. 15). When the output signals of the optical detectors107and118are both the LOW level signals (S3: YES inFIG. 17), the controller90executes the first process, i.e., the controller90determines that the ink cartridge30has reached the mount position (S4inFIG. 17).

When the ink cartridge30has reached the mount position, the irradiation portion34C of the ink amount detection portion34has entered the detection area115of the optical detector114. When the ink cartridge30is new or unused, it stores the predetermined amount or more of ink in the ink chamber36and the light blocking plate62of the detection arm60is positioned in the lower position and blocks light in the detection area115. Thus, the signal output from the optical detector114has changed from the HI level signal to the LOW level signal.

When the ink cartridge30reaches the mount position, the engaging surface45of the rib43passes over the engaging end146of the lock lever145. When this occurs, because the engaging end146of the lock lever145is not supported by the rib43, the lock lever145in the unlock position rotates to the lock position by an urging force of the coil spring148, and the engaging end146of the lock lever145contacts the engaging surface45of the rib43, such that the ink cartridge30is locked in the removal direction54and retained in the mounting position.

Referring toFIG. 12A, when the low-capacity ink cartridge30is inserted into the cartridge holder110in the insertion direction50, the first protruding member75contacts the engaging end146of the lock lever145. With this contact, the lock lever145rotates counterclockwise, the engaging end146moves upward, and the position of the lock lever145changes from the lock position to the unlock position.

Referring toFIG. 12B, when the ink cartridge30is further inserted in the insertion direction50, the triggering portion85enters the detection portion115of the optical detector114, and then the signal output from the optical detector114changes from the HI level signal to the LOW level signal (T5inFIG. 16). In other words, the controller90determines that the optical detector114detects the triggering portion85(S1: Yes inFIG. 17).

When the controller90determines that the optical detector114detects the triggering portion85, it executes the second process in which the type of the ink cartridge30is determined (S2inFIG. 17). In the low-capacity ink cartridge30, the first protruding member75comprises the rib77B, and the second protruding member76comprises the rib80B. Thus, when the controller90determines that the optical detector114detects the triggering portion85, the rib77B is not in the detection area109of the optical detector107and the rib80B is not in the detection area120of the optical detector118. In other words, when the controller90determines that the optical detector114detects the triggering portion85, the signal output from the optical detector107remains unchanged as the HI level signal and the signal output from the optical detector118also remains unchanged as the HI level signal (T5inFIG. 16). The controller90checks the output signals of the optical detectors107,118, i.e., the combination of (HI, HI), in the table stored in the ROM92, to determine the type of ink cartridge30inserted into the cartridge holder110. In this example, the controller90determines that the ink cartridge30inserted into the cartridge holder110is the low-capacity ink cartridge30.

When the ink cartridge30is further inserted in the insertion direction50, the triggering portion85passes over the detection area115of the optical detector114. At this time, the signal output from the optical detector114changes from the LOW level signal to the HI level signal (FIG. 16).

Referring toFIG. 13, when the ink cartridge30is inserted all the way into the cartridge holder110and reaches the mount position, the rib77B enters the detection area109of the optical detector107and the rib80B enters the detection area120of the optical detector118. At this time, the output signals of the optical detectors107and118are both the LOW level signals (T6inFIG. 16). When the output signals of the optical detectors107and118are both the LOW level signals (S3: Yes inFIG. 17), the controller90executes the first process, i.e., the controller90determines that the ink cartridge30has reached the mount position (S4inFIG. 17).

When the ink cartridge30has reached the mount position, the irradiation portion34C of the ink amount detection portion34is in the detection area115of the optical detector114. When the ink cartridge30is new or unused, it stores the predetermined amount or more of ink in the ink chamber36and the light blocking plate62of the detection arm60is positioned in the lower position and blocks light in the detection area115. Thus, the signal output from the optical detector114has changed from the HI level signal to the LOW level signal.

When the ink cartridge30reaches the mounting position, the engaging surface45of the rib43passes over the engaging end146of the lock lever145. When this occurs, because the engaging end146of the lock lever145is not supported by the rib43, the lock lever145in the unlock position rotates to the lock position by an urging force of the coil spring148, and the engaging end146of the lock lever145contacts the engaging surface45of the rib43, such that the ink cartridge30is locked in the removal direction54and retained in the mounting position.

In this embodiment, when the combination of the output signals from the optical detectors107,118are (LOW, LOW), it means that both the first detection information and the second detection information are output. When the combination of the output signals from the optical detectors107,118are (HI, HI), (HI, LOW) or (LOW, HI), it means that at least one of the first detection information and the second detection information is not output.

The dimensions of the inner space of the cartridge holder110are set to be slightly greater than dimensions of the outer shape of the ink cartridge30thereby facilitating insertion of the ink cartridge30into the cartridge holder110. Thus, the ink cartridge30slightly rattles in the cartridge holder110.

If the ink cartridge30placed in the mount position illustrated inFIG. 9,11, or13is inclined clockwise or counterclockwise with respect to the cartridge holder110, and thereby the rib77A or77B of the first protruding member75or the rib80A or80B of the second protruding member76moves out of the detection area109of the optical detector107or the detection area120of the optical detector118, the combination of the output signals of the optical detectors107and118is not (LOW, LOW). In this case, the controller90does not determine that the ink cartridge30has reached the mount position.

If the ink cartridge30is accidentally dropped or collides with other part and at least one of the first protruding member75and the second protruding member76is broken off, the combination of the output signals of the optical detectors107and118is not (LOW, LOW). In this case, the controller90also does not determine that the ink cartridge30has reached the mount position.

As described above, the controller90determines that the ink cartridge30has reached the mount position when the rib77A or77B is detected by the optical detector107and the rib80A or80B is detected by the optical detector118. Thus, whether the ink cartridge30is mounted in position can be properly determined by the controller90.

When the first protruding member75or the second protruding member76of the ink cartridge30is broken off, the controller90does not determine that the ink cartridge30has reached the mount position. Thus, the usage of the ink cartridge30with the first protruding member75or the second protruding member76being broken off can be reduced.

When the printer12is turned off and on again with the ink cartridge30mounted in the cartridge holder110, the controller90determines that the ink cartridge30is mounted only if the rib77aor77B is detected by the optical detector107and the rib80aor80B is detected by the optical detector118. Thus, even when the printer12is turned off and on again with the ink cartridge30mounted in the cartridge holder110, the controller90can determine that the ink cartridge30is mounted.

In the embodiment, the first protruding member75and the second protruding member76are formed integrally with the front wall40of the ink cartridge30. However, the first protruding member75and the second protruding member76may be configured to be removal from the front wall40of the ink cartage30.

In the embodiment, the type of ink cartridge30relates to the initial amount of ink stored in the ink cartridge30. In another embodiment, the type of the ink cartridge30may relate to the color of ink stored in the ink cartridge30.

In another embodiment, the type of the ink cartridge30may relate to the composition of ink. Ink may include a pigment or a dye, or the composition of ink may be tailored for cold climate areas or for tropical regions. When the composition of the ink changes, the viscosity or the surface tension of the ink changes accordingly. Therefore, if the composition of the ink is changed, it may be necessary to change the control of the ink discharge in the recording head21correspondingly. In the embodiment in which the composition of the ink is determined, the image recording is performed with an optimal discharge control in the recording head21.

In another embodiment, the type of the ink cartridges30may relate to the place of manufacture of the ink. When the place of manufacture is determined, such information is stored in the controller90. If a quality problem occurs in the printer12, and the printer12is returned to the manufacturer, the manufacturer can know the place of manufacture of the ink used in the returned printer12based on the information stored in the controller90. Accordingly, studies of the quality problem may become easier. The cartridge type may be divided into two types: an ink cartridge30for general use and an ink cartridge30for maintenance. The ink cartridge30for maintenance is used by a serviceperson who repairs the printer12. When the ink cartridge30for maintenance is mounted in the printer12, a special operation that can not be done by a general user, for example, purging using high-capacity ink, is allowed in the controller90.

In another embodiment, the type of the ink cartridges30may relate to the date of manufacture of the ink. When the date of manufacture is determined, such information is stored in the controller90. If a quality problem occurs in the printer12, and the printer12is returned to the manufacturer, the manufacturer can know the date of manufacture of the ink used in the returned printer12based on the information stored in the controller90. Accordingly, studies of the quality problem may become easier.

In another embodiment, the types of the ink cartridges30may relate to ink cartridge30for general user's use and ink cartridge30for maintenance operator's use. The maintenance operator is a person who is able to repair the printer12at the site of use. The maintenance operator may perform a special operation for repairing the printer12. For example, when the ink cartridge30for the maintenance operator's use is mounted to the printer12, special operations which cannot be performed by the general users such as a purge operation discharging a large amount of ink are authorized by the controller90.

In another embodiment, the type of the ink cartridge may relate to air solubility of ink. If the ink has a low air-solubility, the ink chamber36may not be depressurized. In contrast, if the ink has a high air-solubility, the ink chamber36may be depressurized. A program for maintaining the recording head21is changed based on the determination of the type relating to air solubility of ink.

In this embodiment, the ribs77A,77B,80A and80B and the triggering portion85are configured to prevent the lights emitted from the light-emitting portions of the optical detectors107,114,118, from passing therethrough. In another embodiment, the ribs77A,77B,80A and80B and the triggering portion85may be configured to alter the direction of light, e.g., reflect or diffract the entirety or a portion of light, such that the intensity of light received by the light-receiving portion is reduced. The ribs77A,77B,80A and80B and the triggering portion85may be a smoke glass or an aperture configured to attenuate light, such that the intensity of light received by the light-receiving portion is reduced.

While the invention has been described in connection with various example structures and illustrative embodiments, it will be understood by those skilled in the art that other variations and modifications of the structures and embodiments described above may be made without departing from the scope of the invention. Other structures and embodiments will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and the described examples are illustrative with the true scope of the invention being defined by the following claims.