JP2002292892A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus in which ink end and loading of an ink cartridge can be detected accurately by means of an optical detector. SOLUTION: An ink detection processing executes detection of ink end through an ink sensor every time when the number of ink ejection times exceeds a specified count d. If the number of ink ejection times exceeds the specified count d (S14; Yes), detection position is corrected based on a correction value detected by calibration data input processing and calibration processing for taking in the quantity of reflected light is executed (S15). After the calibration processing is executed (S15), it is judged whether a reflection light level thus taken in is not lower than a first threshold level for determining ink end (S16). Loading of an ink cartridge is detected by judging whether the detected reflection light level is higher than a second threshold level or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an ink jet printer for optically detecting the presence or absence of ink stored in an ink cartridge and the presence or absence of an ink cartridge by an optical detector.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer used as an image forming apparatus such as a printer, a facsimile, a copying machine, etc., has an optical detection device for optically detecting the presence or absence of ink stored in an ink cartridge and the presence or absence of the ink cartridge. An optical detector is provided. This optical detector irradiates light from a light emitting element or the like to an ink cartridge made of a light transmissive substance, and reflects (transmits) the light.
The light amount is detected by a light receiving element. Since the amount of reflected light from the ink cartridge varies depending on the presence or absence of ink and the presence or absence of the ink cartridge, if the amount of reflected light from the ink cartridge is detected, the presence of the ink and the presence or absence of the ink cartridge can be optically detected. Can be.

[0003] Here, depending on the surface condition of the irradiated surface of the ink cartridge, reflected light different from the originally expected reflected light may be reflected from the irradiated surface, and in such a case, detection accuracy is reduced. . For this reason, the inventor of the present application irradiates the irradiated surface of the ink cartridge with light in a non-perpendicular manner (with an inclination angle of about 10 degrees) in order to reduce unnecessary reflected light (noise signal) from the irradiated surface of the ink cartridge. In this way, an optical detector is arranged to reduce a noise signal.

[0004]

However, it is difficult to arrange the optical detector obliquely at a predetermined angle with respect to the irradiated surface of the ink cartridge. If there is an error in the mounting angle, the relative position between the optical detector and the irradiated surface of the ink cartridge deviates from the original set position, and the optical detector causes reflected light (or a part thereof) from the ink cartridge to return to the original position. There is a problem that the detection cannot be performed at the detection position, and the presence or absence of the ink and the presence or absence of the ink cartridge cannot be accurately detected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides an image forming apparatus capable of accurately detecting the presence or absence of ink and the presence or absence of an ink cartridge by using an optical detector. It is intended to be.

[0006]

According to another aspect of the present invention, there is provided an image forming apparatus for irradiating an ink cartridge for storing ink with light and detecting a reflected light amount of the irradiated light. A detector, a detachable ink cartridge capable of changing a reflected light amount of light emitted from the optical detector in accordance with an amount of stored ink, and a carriage reciprocating with the ink cartridge mounted thereon. The optical detector irradiates the irradiated surface of the ink cartridge with light in a non-vertical direction while moving the carriage, and detects the amount of reflected light of the non-vertically irradiated light. First threshold value storage means for storing a first threshold value for testing whether or not the amount of reflected light indicates that there is no ink; A second threshold value storing means for storing a second threshold value to test whether or not showing a mounting,
A test that compares each threshold value stored in the first threshold value storage unit and the second threshold value storage unit with the amount of reflected light to determine whether there is no ink or the ink cartridge is not mounted. Means.

According to the image forming apparatus of the present invention, the irradiation surface of the ink cartridge, which is moved by the reciprocation of the carriage, is irradiated non-vertically by the optical detector. The reflected light amount of the non-vertically irradiated light is changed according to the amount of ink stored in the ink cartridge. The amount of reflected light is detected by the optical detector, and the detected amount of reflected light is stored in the first threshold value and the second threshold value storage means stored in the first threshold value storage means by the verification means. Each is compared with the second threshold value, and it is verified that there is no ink and the ink cartridge is not mounted.

[0008] The image forming apparatus according to the second aspect is the first aspect.
In the image forming apparatus described above, the verification unit stores the amount of reflected light detected at a predetermined position of the ink cartridge by the optical detector in the first threshold storage unit and the second threshold storage unit. The test is performed to determine whether there is no ink and whether the ink cartridge is not mounted, by comparing the threshold values with the threshold values.

According to a third aspect of the present invention, there is provided an image forming apparatus according to the first aspect.
3. The image forming apparatus according to claim 2, wherein the ink consumption amount counting means for counting the ink consumption amount consumed from the ink cartridge, and the ink consumption amount counted by the ink consumption amount counting means reaches a predetermined amount. Determination means for determining whether or not the amount of ink consumption has reached a predetermined amount, and detection execution means for performing detection of the amount of reflected light from the ink cartridge by the optical detector when the determination means determines that the ink consumption amount has reached a predetermined amount. And

According to the third aspect of the present invention, the image forming apparatus operates in the same manner as the first or second aspect of the present invention. When it is determined by the determination means that the predetermined amount has been reached, the detection of the amount of reflected light by the optical detector is executed by the detection execution means.

[0011] The image forming apparatus according to the fourth aspect is the third aspect.
The image forming apparatus according to claim 1, further comprising an empty determination unit configured to determine whether the ink cartridge is empty by counting the ink consumption amount after the inspection unit determines that there is no ink.

[0012] According to a fifth aspect of the present invention, there is provided the image forming apparatus.
3. The image forming apparatus according to claim 2, wherein the amount of ink consumption is counted, and when the counted amount of ink consumption reaches a predetermined amount, the amount of reflected light is detected so that the verification unit verifies the absence of ink in the ink cartridge. And a predetermined amount counting means for initializing the counting.

[0013] According to a sixth aspect of the present invention, there is provided the image forming apparatus.
The image forming apparatus according to any one of claims 1 to 5, wherein the operation mode setting means for setting an operation mode, and the operation mode is set to an adjustment mode for adjusting the apparatus by the operation mode setting means. Position measuring means for measuring the detection position of the ink cartridge by the optical detector; and error calculating means for calculating an error by comparing the detection position of the ink cartridge measured by the position measuring means with a theoretical detection position And an error storage means for storing the error calculated by the error calculation means; and a detection position of the amount of reflected light when testing whether there is no ink or the ink cartridge is not mounted based on the error stored in the error storage means. And a correction execution unit for performing correction relating to

According to the image forming apparatus of the sixth aspect, the operation is the same as that of the image forming apparatus of any one of the first to fifth aspects, and the operation mode setting means adjusts the operation mode. Is set, the detected position of the ink cartridge measured by the position measuring means and the theoretical detected position are compared by the error calculating means, and an error is calculated. The calculated error is stored by the error storage unit, and based on the stored error, the correction regarding the detection position of the reflected light amount when verifying the absence of the ink or the absence of the ink cartridge is executed by the correction execution unit. .

According to a seventh aspect of the present invention, there is provided the image forming apparatus according to the sixth aspect.
In the image forming apparatus described above, the position measuring means moves the carriage at a lower speed than during printing when measuring the detection position of the ink cartridge, and measures the detection position.

[0018] The image forming apparatus according to the eighth aspect is the sixth aspect.
Alternatively, in the image forming apparatus according to claim 7, when the correction execution unit detects that there is no ink or the ink cartridge is not mounted, the correction execution unit moves the carriage to a position that takes into account an error stored in the error storage unit. It is provided with a position correcting means for moving.

According to the ninth aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
9. The image forming apparatus according to claim 1, wherein a plurality of the ink cartridges are mounted on the carriage.

According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, an ink storage chamber for storing ink and an outer wall surface of the ink storage chamber are provided. An ink detection window having a light transmitting property through which light can pass, and being disposed inside the ink reservoir at a predetermined distance from the ink detection window, and changing an optical path of the light transmitted through the ink detection window. Light path changing member,
An ink cartridge in which the ink detection window is inclined at a predetermined angle with respect to the optical path changing member is provided as the ink cartridge.

According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, an ink storage chamber for storing ink and an outer wall surface of the ink storage chamber are provided. An ink detection window having a light transmitting property through which light can pass, and a light absorbing member disposed inside the ink storage chamber at a predetermined distance from the ink detection window to absorb light transmitted through the ink detection window. An ink cartridge having a member is provided as the ink cartridge.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a description will be given using a color ink jet printer that includes four ink cartridges 2 that respectively store black, cyan, magenta, and yellow inks and can execute color printing as an image forming apparatus.

FIG. 1 is a perspective view showing a schematic configuration of a main body of a color ink jet printer 1 according to a first embodiment of the present invention. The color inkjet printer 1 according to the first embodiment is not perpendicular to the irradiated surface of the ink cartridge 2 (inclination angle is approximately 10 degrees) in order to reduce a noise signal (unnecessary reflected light) from the irradiated surface of the ink cartridge 2. An ink sensor 19 arranged to irradiate the ink cartridge with light, and comparing the amount of reflected light detected by the ink sensor 19 with a first threshold value and a second threshold value to determine the presence or absence of ink and the ink cartridge. It is configured such that the presence or absence of attachment can be determined, and the detection position of the ink cartridge 2 can be corrected to accurately detect the amount of reflected light.

This color ink jet printer 1
An ink cartridge 2 filled with four color inks of cyan, magenta, yellow, and black, respectively;
Print head 3 for printing on recording medium P such as recording paper
, A carriage 5 on which the ink cartridge 2 and the head unit 4 are mounted, a drive unit 6 for reciprocating the carriage 5 in a linear direction, and a print head 3 extending in the reciprocating direction of the carriage 5. The apparatus includes a platen roller 7, a purge device 8, and an ink sensor 19 that are arranged to face each other.

On the mounting portion 4a of the head unit 4, three partition plates 4c (see FIG. 2) are erected, and between the pair of side covers 4b formed on both sides of the mounting portion 4a. The mounting portion 4a is partitioned into mounting portions for four ink cartridges 2 via the respective partition plates 4c. In this mounting section, cyan ink, magenta ink, yellow ink,
Four ink cartridges 2 filled with black ink are mounted. The reason that the black ink cartridge 2a has a large volume with respect to each of the ink cartridges 2 filled with the other three color inks is that the black ink is used more frequently than the other colors. Is considered.

The drive unit 6 includes a carriage shaft 9 disposed at the lower end of the carriage 5 and extending parallel to the platen roller 7, a guide plate 10 disposed at the upper end of the carriage 5 and extending parallel to the carriage shaft 9, and a carriage. Axis 9
And two guide pulleys 11 and 12 disposed at both ends of the carriage shaft 9, and an endless belt 13 stretched between the pulleys 11 and 12.

When one of the pulleys 11 is rotated forward and reverse by driving a carriage motor (CR motor) 101, the carriage 5 joined to the endless belt 13 is driven by the forward and reverse rotation of the pulley 11. Is reciprocated in a linear direction along the carriage shaft 9 and the guide plate 10.

The recording medium P is fed from a paper feed cassette (not shown) provided on the side or below the color ink jet printer 1, and is introduced between the print head 3 and the platen roller 7. A predetermined printing is performed by the ink ejected from the print head 3, and then the paper is discharged. In FIG. 1, illustration of a paper feeding mechanism and a paper discharging mechanism of the recording medium P is omitted.

The purge device 8 is provided on the side of the platen roller 7 and is arranged so as to face the print head 3 when the head unit 4 is at the reset position. The purge device 8 includes a purge cap 14 that covers a plurality of nozzles (not shown) of the print head 3 and abuts against an opening surface of the nozzle, a pump 15 and a cam 16,
An ink storage unit 17;
When the print head 3 is at the reset position, the nozzles of the print head 3 are covered with the purge cap 14, and the defective ink containing air bubbles and the like accumulated inside the print head 3 is sucked by the pump 15 by driving the cam 16, thereby performing printing. The head 3 is to be recovered. The sucked defective ink is stored in the ink storage unit 17.

A wiper member 20 is disposed adjacent to the purge device 8 at a position on the platen roller 7 side of the purge device 8. The wiper member 20 is formed in the shape of a spatula, and wipes the nozzle forming surface of the print head 3 as the carriage 5 moves. The cap 18
In order to prevent drying of the ink, the nozzle covers a plurality of nozzles of the print head 3 which is returned to the reset position when printing is completed.

The ink sensor 19 is a sensor for detecting the presence or absence of the ink cartridge 2 and the presence or absence of ink in the ink cartridge 2. It is provided near the end of the drive unit 6 (left side in FIG. 1) and includes an infrared light emitting element 19a (see FIG. 5) and an infrared light receiving element 19b (see FIG. 5). The light irradiation surface of the infrared light emitting element 19a and the light receiving surface of the infrared light receiving element 19b are inclined at the same angle as the inclined portion 51a (see FIG. 4) of the ink cartridge 2 which is inclined at approximately 20 degrees. The ink cartridge 2 is disposed obliquely at an angle of about 10 degrees in the horizontal direction with respect to the inclined portion of the ink cartridge 2 (see FIG. 5). Light emitted from the infrared light emitting element 19a to the ink cartridge 2 is received by the infrared light receiving element 19b as reflected light. The presence or absence of the ink cartridge 2 and the presence or absence of ink in the ink cartridge 2 are detected based on the amount of the received reflected light.

Next, referring to FIG.
A description will be given of a fixing structure of each ink cartridge 2 mounted on the ink cartridge. FIG. 2 is a side view showing a state where the ink cartridge 2 is mounted on the head unit 4, and a cross-sectional view of the head unit 4 and a part of the ink cartridge 2. Note that a two-dot chain line in the figure indicates a state in which the fixed arm 21 is flipped up.

The head unit 4 is a member for detachably mounting the ink cartridge 2 and supplying ink to the print head 3 as described above.
And a fixed arm 21. The mounting portion 4a is a portion where the ink cartridge 2 is mounted, and is formed in a substantially flat surface shape. The mounting portion 4a is partitioned into four spaces by three partition plates 4c, and each ink cartridge 2 is mounted between the partition plates 4c.

An ink supply passage 22 communicating with the print head 3 is formed through the mounting portion 4a. The ink supply passage 22 is connected to the ink supply port 50 of the ink cartridge 2 while being sealed by an O-ring 23. Are in communication. By such communication, ink is supplied from the ink cartridge 2 to the print head 3. On the side of the ink supply passage 22 (on the left side in FIG. 2), a fitting protrusion 24 is provided so as to protrude from the mounting portion 4a. The fitting projection 24 is a member for positioning the ink cartridge 2,
Details will be described later.

The ink cartridge 2 is located behind the fitting projection 24 in the head unit 4 (left side in FIG. 2).
A protrusion 4f is formed to regulate the movement of the vertical direction (the vertical direction in FIG. 2).

The fixed arm 21 is connected to the ink cartridge 2
Is a member for pressing and fixing in a downward direction in FIG. 2,
It is pivotally supported above the head unit 4 (upper side in FIG. 2). The fixed arm 21 is pivotally supported at one end (left side in FIG. 2) by a swing shaft 25, and an auxiliary spring member 26 is wound around the outer periphery of the swing shaft 25. One end of the auxiliary spring member 26 is locked by the spring locking portion 4 d of the head unit 4, and the other end is fixed to the fixed arm 21 while urging force is applied to the fixed arm 21. Therefore, the fixed arm 21
Is held up (upward in FIG. 2) by the biasing force of the auxiliary spring member 26 (indicated by a two-dot chain line in FIG. 2), so that the ink cartridge 2 mounting portion of the head unit 4 is largely opened. Therefore, it is possible to improve the operability of the operator at the time of attaching / detaching the ink cartridge 2.

At the end of the fixed arm 21 (on the left side in FIG. 2), a stopper portion 27 is formed which projects in a triangular shape in a side view. The stopper portion 27 is a part for maintaining the fixed arm 21 in a fixed state of the ink cartridge. The fixed arm 21 has a long hole 2 through which the swing shaft 25 is guided.
1a is formed, and the long hole 21a has a length necessary for the stopper portion 27 to come off from the upper cover 4e. When the projection 21b formed on the fixed arm 21 is pressed, the fixed arm 21 is moved downward in FIG. 2 by the elongated hole 21a, and the engagement between the upper cover 4e and the stopper 27 is released and released. Further, when fixing the ink cartridge 2, when the distal end portion 21 c of the fixed arm 21 in the state indicated by the two-dot chain line in FIG. 2 is pressed down, the fixed arm 21 starts to rotate downward around the swing shaft 25, After the pressing portion 28 described below and the upper wall 56 come into contact with each other, the fixed arm 21 rotates around the contact point with the auxiliary spring member 26 as a center. When the stopper portion 27 moves from the position below the upper cover 4e to the right side of the end 4g of the upper cover 4e, the fixed arm 21 is rotated around the contact point between the pressing portion 28 and the upper wall 56. The elongated hole 21a formed in the arm 21 moves the swinging shaft 25 upward in FIG. 2 to lock the stopper 27 to the end 4g of the upper cover 4e. Therefore, the state where the ink cartridge 2 is pressed by the pressing portion 28 and the locking claw 29 described later can be maintained.

A pressing portion 28 is provided on the lower surface side of the fixed arm 21 (the lower side in FIG. 2). This pressing portion 28
This is a member for pressing the ink cartridge 2 downward (downward in FIG. 2), and a compression spring (not shown) is disposed inside the pressing portion 28 in an elastically compressed state. . The pressing portion 28 is formed so as to be able to advance and retreat, and is normally held in a state of being advanced by a compression spring. As described above, the fixed arm 21 is
When swung to the side, the pressing portion 28 comes into contact with the upper wall 56 of the ink cartridge 2 and retreats rearward. Therefore, the pressing portion 28 can apply an urging force to the ink cartridge 2 by the fixing stopper portion 27 and the compression spring,
The ink cartridge 2 can be pressed downward (downward in FIG. 2).

A locking claw 29 is fixed to the lower surface of the fixed arm 21 on the side of the pressing portion 28 (left side in FIG. 2). The locking claw 29 is a member for positioning the ink cartridge 2, and as shown in FIG. 2, a standing wall portion of a second fitting concave portion 57 described later contacts the locking claw 29. However, a gap is provided between the bottom of the second fitting recess 57 and the locking claw 29. Details of the positioning will be described later.

Next, the internal structure of the ink cartridge 2 will be described with reference to FIG. FIG. 3A is a side sectional view of the ink cartridge 2, and FIG.
FIG. 3A is a partial cross-sectional view taken along the line IIIb-IIIb, and FIG. 3C is a perspective view of the bottom of the ink cartridge 2. FIG. 3A illustrates a state in which no ink is stored in the ink cartridge 2.

As shown in FIG. 3A, the ink cartridge 2 is formed in a substantially hollow box-like body, and the inside of the ink cartridge 2 is defined by partition walls 41 and 42 into an air introduction chamber 43. , A main ink storage chamber 44 and a sub ink storage chamber 45. The atmosphere introduction chamber 43 is a space for introducing the atmosphere into a main ink storage chamber 44 described later, and is communicated with the atmosphere via an atmosphere communication port 47 formed through the bottom wall 46 of the ink cartridge 2. . On the other hand, the upper part (upper side in FIG. 3A) of the air introduction chamber 43 is communicated with the main ink storage chamber 44, and the air is introduced into the main ink storage chamber 44 from the communication part.

The main ink storage chamber 44 is a substantially closed space for storing ink, and contains a foam (porous body) 48 that can be impregnated with ink.
Below the main ink storage chamber 44 (the lower side in FIG. 3A),
An ink communication port 49 is formed through the partition wall 42,
The main ink storage chamber 44 communicates with a sub-ink storage chamber 45 described later via the ink communication port 49. The foam 48 is made of a sponge, a fiber material, or the like capable of holding ink inside by utilizing a capillary phenomenon, and is stored in the main ink storage chamber 44 in a compressed state. Therefore, for example, when the ink cartridge 2 falls, the ink flows out from the main ink storage chamber 44 to the air introduction chamber 43, and the leaked ink leaks out of the ink cartridge 2 from the air communication port 47. Can be prevented.

The sub-ink storage chamber 45 stores ink and is irradiated with infrared light from the ink sensor 19 (see FIG. 4). It is formed as a space. The sub-ink storage chamber 45 communicates with the main ink storage chamber 44 through the ink communication port 49 described above, and the ink stored in the main ink storage chamber 44 and the sub-ink storage chamber 45 The print head 3 (see FIG. 2) through an ink supply port 50 formed through the bottom wall 46
Supplied to

An inclined portion 51a is formed on the side wall 51 of the sub-ink storage chamber 45 so as to be inclined downward toward the main ink storage chamber 44. 3 (a), the prism 52
Are formed.

The prism 52 is a member used for detecting the presence or absence of ink stored in the ink cartridge 2, and is integrated with the inclined portion 51a of the side wall 51 formed of a transparent light-transmitting material. Is formed. In addition, as the light transmitting material, for example, acrylic resin, polypropylene, polycarbonate, polystyrene, polyethylene, polyamide, methacryl, methylpentene polymer, glass, and the like can be used. Further, the above-mentioned transparency does not mean that it is optically completely transparent, but also includes what is called translucent.

As shown in FIG. 3B, the prism 52 has a plurality of reflecting surfaces formed by alternately arranging peaks and valleys. The plurality of reflecting surfaces are inclined downward from one longitudinal end (upper side in FIG. 3A) of the inclined portion 51a toward the other end (lower side in FIG. 3A). They are arranged in the thickness direction (the direction perpendicular to the plane of FIG. 3A). Therefore, the ink can flow down on the prism 52, so that the prism 52
It is possible to prevent the ink from remaining on the prism 52 and preventing the desired reflected light from being obtained from the prism 52.

As described above, the prism 52 is connected to the inclined portion 51a.
3 (b), the infrared light is emitted from the ink sensor in a non-perpendicular direction (in this embodiment, the inclination angle is about 10 degrees) from the direction facing the inclined portion 51a. 19 can be irradiated (FIG. 5
(C)). As a result, it is possible to prevent the infrared light receiving element 19b from detecting reflected light irrelevant to the detection of the presence or absence of the ink reflected on the outer surface of the inclined surface 51a. The reflected light from the prism 52 is mainly received, and the accuracy of detecting the presence or absence of ink is improved.

The infrared light emitted from the infrared light emitting element 19a of the ink sensor 19 toward the inclined portion 51a generally has a predetermined beam angle (around ± 10 degrees). Therefore, the luminous flux of the infrared light spreads, and the amount of light per unit area irradiated on the inclined portion 51a decreases. Therefore, by arranging the prism 52 having a plurality of reflecting surfaces on the inclined portion 51a over substantially the entire area of the inclined portion 51a, the irradiated infrared light can be efficiently reflected, and the infrared light of the ink sensor 2 can be reflected. Light receiving element 19b
Thus, sufficient reflected light can be received. In the prism 52 according to the present embodiment, as shown in FIG. 3B, the intersection angle of the ridge line portion where each reflection surface intersects is approximately 90 degrees, and 16 reflection surfaces are formed. .

Above the sub-ink storage chamber 45, a reflecting member 5 facing the above-mentioned prism 52 at a predetermined interval.
3 are formed. The reflection member 53 is a member for changing the optical path of the infrared light transmitted into the sub ink storage chamber 45, and is formed in a bag shape having an air space in its internal space while having a predetermined angle with the prism 52. Have been.

According to the ink cartridge 2 configured as described above, when ink is consumed by the print head 3, air is introduced from the air introduction chamber 43 into the main ink storage chamber 44 according to the consumed ink amount. As a result, the ink level in the main ink storage chamber 44 decreases (see FIG. 4A). When the ink is further consumed and the ink in the main ink storage chamber 44 runs out, the ink in the sub ink storage chamber 45 is supplied to the print head 3. At this time, the pressure in the sub-ink storage chamber 45 is reduced, but air from the air introduction chamber 43 through the main ink storage chamber 44 is introduced into the sub-ink storage chamber 45 through the ink communication port 49, and The pressure in the chamber 45 is reduced, and the ink level is lowered (see FIG. 4B).

Therefore, first, the ink cartridge 2
After the ink in the main ink storage chamber 44 is consumed and all the ink in the main ink storage chamber 44 is consumed, the ink in the sub ink storage chamber 45 is consumed. Therefore, by detecting the presence or absence of ink in the sub ink storage chamber 45 by the ink sensor 19, it is possible to know the presence or absence of ink in the entire ink cartridge 2.

A first fitting recess 55 is formed in the bottom wall 46 of the ink cartridge 2. The first fitting recess 55 is a member for fitting the fitting protrusion 24 (see FIG. 2) protruding from the mounting portion 4a of the head unit 4 to position the ink cartridge 2, and is a bottom wall. A concave portion 46 is provided at an end opposite to the ink supply port 50 (the left side in FIG. 3A). In addition, the first fitting concave portion 55 is formed as shown in FIG.
As shown in FIG. 3C, the ink cartridge 2 is disposed substantially at the center in the thickness direction (the direction perpendicular to the paper surface of FIG. 3A). Here, the ink supply port 50 of the ink cartridge 2
The ink supply passage 22 of the head unit 4 has an annular groove formed in the outer periphery thereof, and is connected via an O-ring 23 provided in the annular groove (FIG. 2). reference). With only this connection, the ink cartridge 2 rotates around the ink supply port 50 (O-ring 23) due to inertia when the carriage 5 moves, and accurate positioning cannot be performed. Thus, as described above, the first fitting that can be fitted to the fitting projection 24 of the head unit 4 is performed.
By providing the fitting recess 55 in the bottom wall 46 (FIG. 3)
(See (c)), the ink cartridge 2 can be positioned while preventing the ink cartridge 2 from rotating. As a result, the ink cartridge 2 can be accurately fixed to the head unit 4.

On the other hand, a second fitting recess 57 is formed in the upper wall 56 of the ink cartridge 2. The second fitting concave portion 57 is used to connect the ink cartridge 2 to the head unit 4.
This is a portion that fits with a locking claw 29 (see FIG. 2) formed on the fixed arm 21 of the head unit 4 when fixing to the head unit 4. The second fitting recess 57 is for preventing the ink cartridge 2 from laterally shifting in the width direction (the left-right direction in FIG. 3A) and for preventing the ink cartridge 2 from floating. The center of the cartridge 2 in the width direction (the left-right direction in FIG. 3A), that is, the bottom wall 4
6 is recessed at a position corresponding to substantially the center of the ink supply port 50 and the first fitting recess 55 in the width direction of the ink cartridge 2. Therefore, the ink cartridge 2
Are supported in a well-balanced manner by the three points of the second fitting recess 57, the ink supply port 50, and the first fitting recess 55. Accordingly, it is possible to prevent the ink cartridge 2 from rising and tilting in one state, and to firmly fix the ink cartridge 2 to the head unit 4 in a stable state.

Further, both sides of the second fitting recess 57 (FIG. 3)
A pair of side wall plates 58, 58 facing each other at a predetermined interval are provided on the front side and the back side of FIG.
The side wall plates 58, 58 are for preventing lateral displacement of the ink cartridge 2, and the opposing surfaces thereof are in the thickness direction of the ink cartridge 2 (perpendicular to the paper surface of FIG. 3A).
Facing each other. The interval between the opposing surfaces is formed to have substantially the same width as the locking claw 29 (see FIG. 2) of the fixed arm 21 fitted into the second fitting recess 57. Therefore, when the locking claw 29 of the fixed arm 21 is fitted into the second fitting recess 57, the ink cartridge 2 is moved in the thickness direction (perpendicular to the paper surface of FIG. 3A) by the side wall plates 58, 58. (Lateral displacement) is prevented.

Here, as described above, the head unit 4 performs printing while reciprocating in the thickness direction of the ink cartridge 2 (the direction perpendicular to the paper surface of FIG. 3A) (see FIG. 1). During printing, the head unit 4 reciprocates while repeating rapid acceleration and deceleration to improve the printing speed. Therefore, when the ink cartridge 2 is displaced laterally in the moving direction of the head unit 4, the head unit 4 itself vibrates due to the lateral displacement, which adversely affects the print quality. However, the side wall plate 5 described above
8, 58, the ink cartridge 2 is prevented from being laterally displaced (wobbled) in the moving direction of the head unit 4, so that the head unit 4 can smoothly reciprocate without vibrating. A high printing quality can be obtained.

The side of the ink cartridge 2 (FIG. 2)
(Left side) is provided with a pair of ribs 61, 61, which are formed opposite to each other at a predetermined interval like the side walls 58, 58 described above. On the other hand, the locking protrusions 4h (see FIG. 2) are projected from the head unit 4 at positions corresponding to the ribs 61, 61. When the ink cartridge 2 is mounted on the head unit 4, Locking projection 4 between opposing surfaces of ribs 61,61
h is fitted (see FIG. 2). Therefore, the ink cartridge 2 is also prevented from being laterally displaced (wobbled) at the time of printing by the pair of ribs 61, 61.

The upper wall 56 is provided on one side (the left side in FIG. 3A) of the second fitting recess 57 and on the other side (the right side in FIG. 3A). A second upper wall 56b is provided, and the first upper wall 56a is formed to be lower in height from the bottom wall 46 than the second upper wall 56b. On the other hand, the second
A handle 59 is disposed on the side of the upper wall 56b opposite to the first upper wall 56a. The handle portion 59 is a portion that is gripped by an operator when the ink cartridge 2 is mounted on the head unit 4, and is formed to project upward (upward in FIG. 3A) so as to be easily gripped. ing. Therefore, when only one ink cartridge 2 is to be detached from the head unit 4 at the time of replacement of the ink cartridge 2 or the like, by gripping the handle 59, the other adjacent ink cartridge 2
Can be removed without obstruction. On the other hand, when the ink cartridge 2 is mounted, the user can easily mount the ink cartridge 2 in a narrow space by gripping the handle 59 and holding the ink cartridge 2.

When the ink cartridge 2 is mounted on the head unit 4, the ink cartridge 2
The first upper wall 56a is inserted into a predetermined portion of the head unit 4 from the side, and the first upper wall 56a is, as described above,
The height from the bottom wall 46 is low. for that reason,
The first upper wall 56a and the fixed arm 21 flipped upward.
Can be prevented from interfering with the vicinity of the shaft support (the side opposite to the stopper 27), so that the ink cartridge 2 can be easily mounted without being hooked on the head unit 4 (see FIG. 2).

The reason why the entire upper wall 56 is not made thin is to maintain the rigidity against the pressing of the pressing portion 28.

A first convex portion 62 projects upward (upward in FIG. 3) on the side (right side in FIG. 3) of the first upper wall 56a. Has one side wall formed by the first convex portion 62. for that reason,
When the locking claw 29 of the fixed arm 21 is fitted into the second fitting recess 57, the ink cartridge 2 is moved (laterally) in the width direction (right direction in FIG. 3A) by the first protrusion 62. The ink cartridge 2 can be prevented from shifting, and the ink cartridge 2 can be prevented from rising.

Next, the principle of detecting the presence or absence of ink will be described with reference to FIGS. FIGS. 4 (a) and 4 (b)
FIG. 3 is a side view of the ink cartridge 2 and the ink sensor 19, and shows a part of the ink cartridge 2 in cross section.
4A and 4B, the head unit 4, the attachment members for the ink sensor 19, and the like are schematically shown.

When the ink 71 is sufficient in the ink cartridge 2, as shown in FIG. 4A, the infrared light emitted from the infrared light emitting element 19a of the ink sensor 19 (optical path X) Since the refractive index of the material of the ink cartridge 2 and the refractive index of the ink 71 are very close, the ink cartridge 2 travels through the ink cartridge 2 while passing through the ink 71. And
The light reaches the reflection member 53 provided in the sub ink storage chamber 45. The infrared light that has reached the reflecting member 53 is reflected at the interface between the inner surface of the reflecting member 53 and the air 72 because the refractive index of the material of the reflecting member 53 and the refractive index of the air 72 are different (optical path Y).

Here, the inclined portion 5 of the ink cartridge 2
Since 1a is inclined at about 20 degrees with respect to the reflecting member 53, the incident angle of the infrared light reaching the reflecting member 53 is different from the incident angle to the inclined portion 51a. Therefore, the reflected light (optical path Y) reflected by the reflecting member 53 is reflected at an angle different from that of the incident light. Therefore, the reflected light (infrared light) does not go to the infrared light receiving element 19b of the ink sensor 19, and the amount of reflected light going to the infrared light receiving element 19b is small.

On the other hand, when the ink 71 does not exist in the sub ink storage chamber 45 of the ink cartridge 2, as shown in FIG. The obtained infrared light (optical path X)
Since the refractive index of the material of the ink cartridge 2 is different from the refractive index of air, the light is reflected at the interface between the inner surface of the outer wall of the sub ink storage chamber 45 and the air (optical path Y). Therefore, the infrared light receiving element 19 of the ink sensor 19 is
The amount of reflected light traveling toward b becomes large.

As described above, the amount of the reflected light (optical path Y) reflected from the inside of the ink cartridge 2 changes in accordance with the presence or absence of the ink.
The presence or absence of the ink stored in the ink cartridge 2 can be detected by performing the detection using the nine infrared light receiving elements 19b.

The inclined portion 51a and the reflecting member 53 are
Since the ink 71 is disposed above the sub-ink storage chamber 45, the ink is stored in advance before the ink 71 is no longer present above the sub-ink storage chamber 45, that is, before all the ink 71 is present in the ink cartridge 2. It is possible to judge that there is no.

In this embodiment, the inclined portion 51a
Is approximately 20 degrees, but is not limited to such an angle, and may be in the range of approximately 15 degrees to approximately 25 degrees. That is, by making the angle approximately 15 degrees or more, it is possible to suppress the reflected light from the reflecting member 53 from returning to the infrared light receiving element 19b, and by making the angle approximately 25 degrees or less, the ink is always stored in the inclined portion 51a. Can be suppressed.

Next, the reason why the ink sensor 19 is disposed obliquely at an angle of about 10 degrees in the horizontal direction with respect to the inclined portion 51a (see FIG. 3) of the ink cartridge 2 which is the surface to be irradiated with infrared light. This will be described with reference to FIG. FIG. 5 is a top view illustrating the ink cartridge 2 and the ink sensor 19. The ink cartridges 2a to 2d mounted on the head unit 4 are reciprocated in the direction of arrow W.

First, when the ink sensor 19 is disposed perpendicular to the inclined portion 51a (see FIG. 5A), light (optical path X) emitted from the infrared light emitting element 19a is The light passes through the inclined portion 51a formed by the transparent member. However, incident light (optical path X) that should pass through the inclined portion 51a may be reflected by the outer surface of the inclined portion 51a due to fine irregularities on the surface outside (the side opposite to the ink) of the inclined portion 51a. . Then, when the reflected light (optical path Y) is received by the infrared light receiving element 19b, it is determined that the ink 71 does not exist even though the ink 71 exists in the sub ink storage chamber 45. This may cause adverse effects on the original detection accuracy of the presence or absence of ink.

On the other hand, when the ink sensor 19 is disposed at an angle larger than approximately 10 degrees with respect to the inclined portion 51a (FIG. 5).
(See (b)), for example, even when the ink cartridge 2b does not exist, the light (optical path X) emitted from the infrared light emitting element 19a may be reflected by the adjacent ink cartridge 2c. is there. When the reflected light (optical path Y) is received by the infrared light receiving element 19b, it may be determined that the ink cartridge 2b exists even though the ink cartridge 2b does not exist. In some cases, the presence or absence of the cartridge 2b cannot be detected.

Therefore, the ink sensor 19 is moved to the inclined portion 51a.
(See FIG. 5 (c)), the infrared light receiving element 19b is inclined, so that it is reflected by the surface outside the anti-ink side of the inclined portion 51a. (See the optical path Y in FIG. 5A). Therefore, when ink is present, light transmitted through the inclined portion 51a is not received as described with reference to FIG.
On the other hand, when there is no ink, the reflected light (optical path Y) from the interface between the inside of the inclined portion 51a (the side of the sub ink storage chamber 45) and the air is received by the infrared light receiving element 19b. Therefore, the presence or absence of ink can be accurately determined based on the difference in the light amount. Even when there is no ink cartridge 2c, the light emitted from the infrared light emitting element 19a does not irradiate the adjacent ink cartridge 2d (see the optical path X1).
Can be determined.

In the present embodiment, the inclination is set to approximately 10 degrees.
Since the angle is determined by various factors such as the space between the ink cartridges 2 and the space between the ink cartridge 2 and the ink sensor 19, it is sufficient that the ink cartridge 2 has an inclination.
It is not limited to such an angle.

FIG. 6 shows a color ink jet printer 1
FIG. 2 is a block diagram schematically showing an electric circuit configuration of FIG. The control device for controlling the color inkjet printer 1 includes a main body control board 100 and a carriage board 120. The main body control board 100 includes a microcomputer (CPU) 91 having a one-chip configuration,
ROM 92 which stores various control programs and fixed value data executed by 91, RAM 93 which is a memory for temporarily storing various data and the like, EEPROM 94 which is a rewritable nonvolatile memory, an image memory 95, a gate array 96, and the like.

The CPU 91 as an arithmetic unit has a ROM 92
In accordance with a control program stored in advance, control for detecting the presence or absence of ink and for detecting whether or not an ink cartridge is mounted is executed. Further, it generates a print timing signal and a reset signal, and transfers each signal to a gate array 96 described later. The CPU 91 includes an operation panel 107 for a user to issue a print instruction and the like, and a carriage motor (CR motor) 10 for operating the carriage 5.
Drive circuit 102 for driving the recording medium P
Drive circuit 104 for operating a transport motor (LF motor) 103 for transporting a sheet, a recording medium (print paper)
A paper sensor 105 for detecting the tip of P, an origin sensor 106 for detecting the origin position of the carriage 5, an ink sensor 19, and the like are connected. The operation of each connected device is controlled by the CPU 91.

In the ROM 92, as a part of the control program, the positional relationship (relative position) between the ink sensor 19 and the irradiated surface of the ink cartridge 2, that is, the detected position of the ink cartridge 2, is measured, and the theoretical value is calculated. Calibration data input processing for inputting the deviation (correction value) as calibration data (see FIG. 7), ink detection processing for detecting the presence or absence of ink in the ink cartridge 2 (see FIG. 8), ink cartridge mounting A program of an ink cartridge detection process (see FIG. 10) for detecting the presence / absence of an ink cartridge is stored. Details of each program will be described later. In addition, as fixed value data, a first threshold value for testing ink absence at a detected reflected light level, a second threshold value for testing ink cartridge non-mounting at a detected reflected light level, an ink level An empty threshold value or the like, which is the number of ink ejections from when the (ink remaining amount in the ink cartridge 2) becomes near empty to empty, is stored.

The RAM 93 stores the maintenance mode flag 9
3a. Maintenance mode flag 93a
Is a flag indicating that the operation mode of the color inkjet printer 1 is set to the maintenance mode for adjusting the color inkjet printer 1. The maintenance mode is set by operating a mode switch 107a provided on the operation panel 107. By the selection of the maintenance mode, the maintenance mode flag 93a is turned on. The maintenance mode flag 93a that has been turned on is turned off when a command indicating the end of adjustment of the color inkjet printer 1 is input. The above-described calibration data input process is a program that can be executed when the maintenance mode flag 93a is turned on.
The correction value can be stored only when the flag 93a is on.

The EEPROM 94 has a calibration data memory 94a and first to fourth counters 94b to 94b.
e and the first to fourth near empty flags 94f to 94i
It has. Calibration data memory 94a
Is a memory for storing, as calibration data, a correction value detected by the calibration data input process, that is, a displacement from the original detection position of the ink cartridge 2.

As described above, in the color ink jet printer 1 of the present embodiment, the ink sensor 19 is installed at an angle of about 10 degrees with respect to the irradiated surface of the ink cartridge 2. However, due to a mounting angle error generated when the sensor 19 is mounted, the angle is approximately 10 degrees.
Often not. In such a case, the relative position between the ink sensor 19 and the ink cartridge 2 is different from the original position. That is, the ink cartridge 2
The ink cartridge 2 is deviated from the original detection position, and the ink sensor 19 cannot accurately detect the ink cartridge 2 at the original detection position. For this reason, the calibration data input processing executed before shipment detects a deviation between the original detection position and the actual detection position, and the deviation amount is used as a correction value (prior to shipment) in this calibration data memory. 94a.

When detecting the presence / absence of the ink cartridge 2 (verification of the absence of the ink cartridge) and the presence / absence of the ink (verification of the absence of the ink), the correction value stored in the calibration data memory 94a is referred to. The detection position (the position of the carriage 5) for detecting the amount of reflected light is adjusted based on the correction value. Accordingly, even if the positional relationship between the ink sensor 19 and the irradiated surface of the ink cartridge 2 is deviated from the original position, the presence or absence of the ink cartridge 2 and the presence or absence of ink can be accurately detected.

The first to fourth counters 94b to 94e are memories for counting up the number of ink ejections (ejections) from the print head 3, and are updated by "1" every time the number of ink ejections is "1". Is done. A predetermined amount of ink is initially injected into the ink cartridge 2, and the approximate maximum number of ejections is determined from the amount of ink.
Therefore, by counting the number of times of ink ejection, it is possible to know the approximate amount of ink consumption.

The color ink jet printer 1 has four ink cartridges 2 for storing inks of black, cyan, magenta, and yellow, respectively. Therefore, four counters ( First to fourth counters 94b to 94
e) are provided, and the first to fourth counters 94b to 94c correspond to the number of ink ejections counted for each ink.
94e. The count values stored in the first to fourth counters 94b to 94e are referred to by the ink detection processing, and each time the count value reaches a predetermined number, the actual ink level (the ink level in the ink cartridge 2) In order to check the remaining amount, ink detection by the ink sensor 19 (ink detection processing, see FIG. 8) is executed.

A predetermined amount of ink is ejected from the ink cartridge 2 not only at the time of printing, but also at a purging process for sucking out bubbles in the ink cartridge 2 and a flushing process for solving clogging of nozzles. . Regarding the ink consumed in such a process, it is already known how many counts of the number of ejections at the time of printing correspond. Therefore, the corresponding count is added to the previously stored count value, and The count values of the first to fourth counters 94b to 94e are updated.

The first to fourth near empty flags 94f to 94f
The flag 94i is provided for each of the four ink cartridges 2 for storing inks of black, cyan, magenta, and yellow, respectively.
ON of f to 94i indicates near empty of the ink. Here, the near empty is the ink sensor 19
Indicates a detection limit of ink, and indicates a state in which the ink sensor 19 detects that there is no ink.

As described with reference to FIGS. 3 and 4, the ink filled in the initial state is consumed from the main ink storage chamber 44, and when the main ink storage chamber 44 becomes empty, the sub ink storage chamber 4 becomes empty.
5 inks are consumed. When the ink level of the sub ink storage chamber 45 falls below the lower portion of the reflection member 53, the ink sensor 1
The light emitted from the infrared light emitting element 19a of the ink sensor 19 is
The light is reflected in the direction (optical path Y). As a result, the amount of reflected light detected by the infrared light receiving element 19b of the ink sensor 19 greatly changes (increases). Since the detected amount of reflected light is input as a signal to the CPU 91, such a change is recognized by the CPU 91 as near empty, and the corresponding near empty flags 94f to 94i are turned on.

The first to fourth near empty flags 94
At the point when f to 94i are turned on (the ink sensor 19 detects that there is no ink), the ink in the ink cartridge 2 is not empty, so the state of the ink empty (the number of times of ink ejection is the empty threshold) is further increased. Until the value is reached).

In this embodiment, in order to accurately detect ink empty, when the first to fourth near empty flags 94f to 94i are turned on, they are stored in the corresponding first to fourth counters 94b to 94e. The count value 0 is cleared, and the count from 0 to the empty threshold value is counted up, thereby improving the detection accuracy of the ink empty. The turned on first to fourth near empty flags 9
The ink cartridges 4f to 94i are turned off when the ink level of the corresponding ink cartridge 2 is detected as having ink, for example, by replacement (see FIG. 10).

The above-mentioned CPU 91, ROM 92, RA
M93, EEPROM 94 and gate array 96 are:
They are connected via an address bus 98 and a data bus 99.

The gate array 96 is provided with an image memory 95 according to a print timing signal transferred from the CPU 91.
Print data (drive signal) for printing the image data on a recording medium based on the image data stored in the printer
And a transfer clock CLK synchronized with the print data;
A latch signal, a parameter signal for generating a basic print waveform signal, and an ejection timing signal JET output at a constant period are output, and these signals are transferred to the carriage substrate 120 on which the head driver is mounted. . The gate array 96 causes the image memory 95 to store image data transferred from an external device such as a computer via the centro interface 97. Then, the gate array 96 generates a Centro data reception interrupt signal based on the Centro data transmitted from the host computer or the like via the Centro interface 97, and transfers the signal to the CPU 91. Each signal communicated between the gate array 96 and the carriage substrate 120 is transferred via a harness cable connecting them.

The ink sensor 19 includes an infrared light emitting element 19
a and an infrared light receiving element 19b.
9a irradiates the ink cartridge 2 with infrared light (see FIG. 4).
And the reflected light (optical path Y in FIG. 4) is detected by an infrared light receiving element 19b as a photosensor. The reflected light received by the infrared light receiving element 19b is
The light is photoelectrically converted by the infrared light receiving element 19b and is detected as an electric signal corresponding to the received reflected light amount. Since the detected signal is an analog signal, the infrared light receiving element 19
After being converted into a digital signal by the A / D converter 19c connected to the terminal b, the signal is input to the CPU 91. The amount of reflected light detected by the ink sensor 19 is compared with a first or second threshold value in an ink detection process or an ink cartridge detection process. Thus, it is possible to know whether or not the ink cartridge 2 has ink and whether or not the ink cartridge is mounted. The A / D converter 19c converts an analog signal into a digital signal through steps such as sampling, quantization, and binary conversion.

The carriage substrate 120 is a substrate for driving the print head 3 by a mounted head driver (drive circuit). The print head 3 and the head driver are connected by a flexible wiring board in which a copper foil wiring pattern is formed on a polyimide film having a thickness of 50 to 150 μm. This head driver is provided on the main body side control board 1
00 via a gate array 96 mounted at
A drive pulse having a waveform suitable for the recording mode is applied to each drive element. Thereby, a predetermined amount of ink is ejected.

Next, with reference to the flowcharts shown in FIGS. 7 to 10, each processing executed in the color ink jet printer 1 configured as described above will be described.

FIG. 7 is a flowchart showing a calibration data input process which is one of the control programs. This calibration data input process is a process executed before shipment to detect a positional deviation of the detection position of the ink cartridge 2 and store the deviation amount as a correction value in the calibration data memory 94a.

This calibration data input processing can be executed only when the operation mode of the color ink jet printer 1 is set to the maintenance mode for performing the adjustment. Therefore, in this calibration data input processing, first, It is determined whether the maintenance mode flag 93a is turned on (S
1) If it is not turned on (S1: No), this calibration data input processing ends. On the other hand, if the maintenance mode flag 93a is on (S
1: Yes), after confirming that the carriage 5 is at the origin by the origin sensor 106, the carriage 5 is moved to the home position by driving the CR motor 101 to move the carriage 5 a predetermined distance from the origin (S2). .
Next, the infrared light emitting element 19a is turned on with a predetermined light amount (S
3) The carriage 5 is moved at a low speed toward the ink sensor 19 (S4). When the carriage 5 reaches a predetermined detection position (when the carriage 5 moves a predetermined distance from the origin),
The detection of the amount of reflected light by the ink sensor 19 is started, the level of reflected light (reflected light amount) reflected by the ink cartridge 2 is received by the infrared light receiving element 19b, and is taken into the CPU 91 via the A / D converter 19c ( S
5). The detection of the reflected light level is performed not only at the original detection position of the ink cartridge 2 but also over a wider range than the width of the carriage 5, and the reflected light level is detected as analog data (see FIG. 11).

Next, the change position of the detection signal indicating the reference ink cartridge 2 at which the level changes from the level without the ink cartridge to the level with the ink cartridge is detected (S6). At the position where the ink cartridge 2 is not provided (not mounted), the reflection of the irradiated infrared light is small, and therefore, the detected reflected light level at the level without the ink cartridge 2 is small. On the other hand, at the position where the ink cartridge 2 is located (mounted), the reflection of the irradiated infrared light is large, and the detected reflected light level at the level with the ink cartridge is also large. That is, this change position where the reflected light level changes from the ink cartridge absence level to the ink cartridge presence level is the detection position of the ink cartridge 2 (see FIG. 11).

Then, the deviation (theoretical value) between the change position (theoretical value) from the theoretically no ink cartridge level and the ink cartridge present level, which should be obtained, and the change position (actual value) detected in the process of S6. Is calculated as the movement distance α of the carriage, and the deviation is stored in the calibration data memory 94a as a correction value (S7). Here, the original detection position (theoretical value) is stored as the moving distance of the carriage 5 from the origin. Therefore, the actual detection position is the theoretical movement distance ± α, and the distance ± α is the correction value.

The correction value stored in the calibration data memory 94a in the calibration data input processing is used for the calibration processing (S1) executed in the ink detection processing and the ink cartridge detection processing.
Used in 5). Thereby, the detection position when detecting the reflected light from the ink cartridge 2 is corrected,
The reflected light level can be accurately detected.

In the present embodiment, the actual detected position and the theoretical detected position of the reference ink cartridge 2 were compared in the process of S6, but this reference ink cartridge 2 was mounted on the carriage 5. The leading ink cartridge 2 of the four ink cartridges 2, that is, the ink cartridge 2 that is detected first (reaches the detection position).

FIG. 8 is a flowchart showing an ink detection process for detecting the ink, that is, detecting the presence or absence of the ink 71 in the ink cartridge 2. The ink detection process is a process that is repeatedly executed at a predetermined timing to detect the amount of ink consumed when the print head 3 operates.

In this ink detecting process, first, it is checked what kind of process is being executed in the color ink jet printer 1 (S11). If the process being executed is printing (S11: printing), a one-pass printing process for printing one pass is executed (S12). In this one-pass printing process (S11), in order to calculate consumed ink, the number of times of ink ejection from each ink cartridge 2 is counted, and the counted number is stored in the corresponding first to fourth counters 94b to 94e. Count up the count value.

Next, the first to fourth ink cartridges 2
It is confirmed whether or not the near empty flags 94f to 94i are turned on (S13). As a result of the confirmation, the first to fourth
If the near empty flags 94f to 94i are off (S13: No), the count value of the ink cartridge 2 corresponding to the turned off (flag off) first to fourth near empty flags 94f to 94i is determined. It is confirmed whether or not there is a count value equal to or larger than a predetermined number d (for example, 100) (S14). In the ink detection process, the ink sensor 19 detects the presence or absence of ink every time the number of times of ink ejection reaches a predetermined number d.

If the count value is equal to or more than a predetermined number d (for example, 100) (S14: Yes), the detection position is corrected and reflected so that the ink sensor 19 detects the presence or absence of ink (no ink). A calibration process for capturing the light level (reflected light amount) is executed (S
15). After the execution of the calibration processing (S15), it is determined whether or not the level of the captured reflected light is equal to or higher than the first threshold (S16). This first threshold is
This is a reflected light level for distinguishing between the presence and absence of ink.

As a result of the judgment in S16, if the level of the reflected light is higher than the first threshold (S16).
16: Yes), the ink liquid level in the sub ink storage chamber 45 is lower than the lower part of the reflection member 53, indicating that the ink level (the remaining amount of ink in the ink cartridge 2) is near empty. Tested as no ink). For this reason, the first ink cartridge 2
The fourth to fourth near empty flags 94f to 94i are turned on (S17), and the corresponding count value (corresponding first to
(Count values stored in fourth counters 94b to 94e)
Is set to 0 (S18). Thereafter, the other processes are executed (S19), and the ink detection process ends.

Also, as a result of the confirmation in the processing of S11, if the processing being executed is purge or flushing (S1
1: purge and flushing), and perform a purge and flushing process (S22). The purge and flushing process (S22) is a process of performing a purge process of discharging ink to suck out bubbles in the ink cartridge 2, or a process of performing a flushing process of discharging ink to eliminate clogging of the print head 3. It is. In this purge and flushing process (S22), a predetermined amount of ink is discharged. It is known how many times the ink amount corresponds to the number of ejections during printing, and such a value is stored in the ROM 92 in advance. It is stored as a fixed value. Therefore, the ink consumed by the number of ejections is counted, and the first to fourth counters 9 corresponding to the counted number are counted.
The count values stored in 4b to 94e are counted up. After executing the purging and flushing processing (S22), the processing shifts to the processing of S13.

On the other hand, as a result of the confirmation in S13, the first to fourth near empty flags 9
If 4f to 94i are ON (S13: Yes), the count value of the ink cartridge 2 corresponding to the ON (flag ON) first to fourth near empty flags 94f to 94i is equal to or greater than the empty threshold value. It is confirmed whether or not (S20). Since the ink levels of the ink cartridges 2 corresponding to the flag-on first to fourth near empty flags 94f to 94i have exceeded the ink detection limit of the ink sensor 19, the number of ink ejections after the near empty is counted. By doing so, the ink empty is detected.

Here, if the confirmed count value is less than the empty threshold value (S20: No), there is still ink remaining to be able to execute printing.
After performing the process (S19) by shifting to the process of No. 9, the ink detection process ends. Also, as a result of the confirmation in the processing of S20, the first to fourth near empty flags 9
If the count value of the ink cartridge 2 corresponding to 4f to 94i is equal to or larger than the empty threshold value (S20: Y
es) Ink empty processing for displaying ink empty or the like is executed (S21). After execution of the processing of S21, the processing shifts to the processing of S19, and each processing such as temporarily storing data that could not be printed (S19)
Is executed, the ink detection process ends.

As a result of checking in step S14, if there is no count value equal to or larger than the predetermined number d (for example, 100) (S14; No), the process shifts to step S19 to execute each process ( After executing S19), the ink detection process ends.

Further, as a result of the confirmation in the processing of S16, if the level of the reflected light taken in is less than the first threshold value (S1).
6: No), since the ink level is not near empty, the process of S17 is skipped, and the process shifts to the process of S18.

When the replacement (removal) of the ink cartridge 2 is performed (ink cartridge detection processing), the first to fourth counters 94 corresponding to the ink cartridge 2 are used.
The count values of b to 94e are set to 0, and the counting of the number of ink ejections is started. However, the replaced ink cartridge 2 has a reduced ink filling amount due to, for example, installation of used articles or manufacturing variations. Have variations. Also, in consideration of variations in the amount of ink ejected from the print head 3 of each color inkjet printer 1, the count values up to near empty are not always the same. For this reason, if the count from the initial state to the ink empty is continuously counted up, it becomes difficult to determine the ink empty with a certain threshold value (predetermined count value). Ink empty tends to be inaccurate. However, when the near empty is detected, the remaining amount of ink in the ink cartridge 2 is considered to be substantially the same, so that the number of ink ejections (count value) required to consume the remaining amount of ink becomes the same. Conceivable. Therefore, if the predetermined number near the number of times of ejection is set as the empty threshold, and the time when the near empty state is detected (near empty flag is turned on) is counted as 0, and counting up to the empty threshold is performed,
Ink empty can be detected accurately.

FIG. 9 is a diagram showing a flowchart of the calibration process (S15) executed in the ink detection process of FIG. This calibration processing (S15) corrects the detection position of the ink cartridge 2 based on the correction value stored in the calibration data memory 94a in order to detect the presence or absence of ink,
Reflected light level (reflected light amount) at the corrected detection position
This is the process of capturing the data.

In the calibration processing (S15), first, the carriage 5 is moved to the home position (S31). Then, from this home position, the carriage 5 is moved in the direction of the ink sensor 19 (S32), and it is checked whether or not the carriage 5 has reached a position where the correction value has been added to the original detection position of the one ink cartridge 2. (S33). If the carriage 5 has reached the detection position to which the correction value has been added (S33: Yes),
The infrared light emitting element 19a is turned on with a predetermined light amount, and the reflected light level is detected (S34). Next, it is confirmed whether or not the reflected light levels have been detected for the four (all) ink cartridges 2 (S35). If all such reflected light levels have been detected (S35: Yes), this calibration is performed. The process (S15) ends.

On the other hand, as a result of the confirmation in the processing of S33, if the carriage 5 has not reached the detection position to which the correction value has been added (S33: No), the processing shifts to the processing of S32, and the carriage 5 is moved to the ink sensor. Move in 19 directions.
As a result of the confirmation in the processing of S35, if the reflected light levels of all the ink cartridges 2 have not been detected (S35).
35: No), the process proceeds to the process of S32, and the calibration process (S15) is executed until the reflected light levels of all the ink cartridges 2 are detected.

In the calibration process (S15), a predetermined position (one point) of each ink cartridge 2 is set.
The ink sensor 19 detects the amount of reflected light (reflected light level) reflected from the ink. That is, the reflected light level is pinpoint data detected pinpoint. Therefore, the amount of data to be processed can be reduced, and data processing can be performed efficiently. Further, since the detection of the presence or absence of the ink is performed during the printing operation, the carriage 5 is moved at a high speed, but each of the ink cartridges 2 is accurately positioned based on the correction value stored in the calibration data memory 94a. Transported to Therefore, the reflected light level can be accurately detected (even with point data).

FIG. 10 is a flowchart showing the ink cartridge detection process. This ink cartridge detection process is a process for detecting whether or not an ink cartridge is mounted. Therefore, the ink cartridge 2
Is performed at the timing when the ink cartridge is replaced, but the sensor provided on the cover of the color inkjet printer 1 recognizes that the cover is open or closed, and recognizes that the ink cartridge has been replaced.

In the ink cartridge detection process, first, it is checked whether the cover has been opened and then closed (S41). When it is detected that the cover is closed, the above-described calibration processing (S15) is executed, and the detection of the reflected light of the ink cartridge 2 is executed at a predetermined detection position. Thereafter, whether the reflected light level of the ink cartridge 2 for which the first to fourth near empty flags 94f to 94i are turned on is less than the first threshold value, that is, whether or not the ink is in a filled state. (S43), and as a result, if the reflected light level is less than the first threshold value (S43: Yes), it means that the ink cartridge 2 having a small amount of remaining ink has been replaced, and this corresponds. The near empty flags 94f to 94i of the ink cartridge 2 are turned off (S44), and the count values of the corresponding counters 94b to 94e of the ink cartridge 2 are cleared (S45). Thereafter, it is checked whether or not four reflected light levels that are equal to or higher than the second threshold value (threshold value for verifying that the ink cartridge is not mounted) are detected (S46). When the following reflected light level is detected (S46: No), it is determined that the ink cartridge is not mounted, and the ink cartridge absence error process for notifying the ink cartridge not mounted is executed (S47). The ink cartridge detection process ends.

If it is determined in step S41 that the cover is not closed (S41: No), the ink cartridge detection process ends. Further, as a result of the confirmation in the processing of S43, if the reflected light level is equal to or higher than the first threshold value (S43: No), the processing shifts to the processing of S46. On the other hand, as a result of the confirmation in the processing of S46, the second
If four reflected light levels exceeding the threshold value have been detected (S46: Yes), it means that the ink cartridges 2 are all mounted, and the ink cartridge detection process ends.

FIG. 11 is a diagram schematically showing a change in the reflected light level of the ink cartridge 2. As shown in FIG. The vertical axis indicates the amount of reflected light, and the higher the vertical axis, the larger the amount of reflected light. A first threshold value for testing the absence of ink is indicated by a dashed line. A value equal to or higher than the first threshold value is a reflected light level indicating no ink (near empty). The reflected light level indicates presence. Below the first threshold value, a second threshold value for verifying that the ink cartridge is not mounted is indicated by a broken line.

FIG. 11A is a diagram showing the theoretical reflected light level detected at the original detection position. As shown in the figure, if the obtained reflected light level (signal waveform) is tested with the first threshold value, the presence or absence of ink can be detected, and the same reflected light level is smaller than the first threshold value. If the test is performed using the second threshold value, the presence or absence of the ink cartridge 2 can be detected. This is because a clear reflected light amount difference is obtained between the presence and absence of the ink and the presence and absence of the ink cartridge.

FIG. 11B is a diagram showing a signal waveform of the reflected light level detected in the calibration data input processing. FIG. 11B shows the signal waveform of the reflected light level when the mounting angle of the ink sensor 19 is shifted in the vertical direction with respect to the irradiated surface of the ink cartridge 2, and the actual detection position is the original detection position. It is shown that it is closer to the detection position. Ink cartridge 2 for storing top black ink
Reference symbol a denotes an ink cartridge serving as a reference in the calibration data input process, and the shift amount α from the original detection position of the black ink cartridge 2a is a correction value.

Next, a second embodiment will be described with reference to FIG. While the ink cartridge 2 of the first embodiment is configured to change the optical path of the infrared light by the reflecting member 53, the ink cartridge 1 of the second embodiment
Reference numeral 30 includes an infrared light absorbing member 131 that absorbs infrared light. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIGS. 12A and 12B are side views of the ink cartridge 130 and the ink sensor 19, and show a part of the ink cartridge 130 in a sectional view. In addition,
FIGS. 12A and 12B schematically show the head unit 4, the attachment member for the ink sensor 19, and the like omitted.

In the ink cartridge 130, a prism 52 is formed on the inner surface side (ink interface side) of the inclined portion 51a to which infrared light is irradiated, as in the first embodiment. Is a form 48
And a sub-ink storage chamber 45 in which an infrared light absorbing member 131 to be described later is stored is defined by a partition wall 42. The infrared light absorbing member 131 is an infrared light emitting element 19a of the ink sensor 19.
The member is a member for absorbing infrared light emitted from the ink cartridge 130 and transmitted through the ink cartridge 130, and is provided in the sub-ink storage chamber 45 so as to face the prism 52 at a predetermined interval.

Next, a detection method for detecting the presence or absence of the ink 71 in the ink cartridge 130 provided with the infrared light absorbing member 131 will be described. The ink sensor 19 is
As in the first embodiment, infrared light is emitted from the infrared light emitting element 19a toward the inclined portion 51a of the ink cartridge 130. Then, the reflected light is received by the infrared light receiving element 19b, and when the amount of the reflected light is equal to or less than a predetermined value, it is determined that there is ink in the ink cartridge 130 (in the case of FIG. 12A), If the amount of the reflected light is equal to or more than a certain value, it is determined that there is no ink in the ink cartridge 130 (in the case of FIG. 12B).

More specifically, when the inside of the sub-ink storage chamber 45 is filled with the ink 71, as shown in FIG. Since the refractive index of the material of the optical path X) and the inclined portion 51a (prism 52) is very close to the refractive index of the ink 71, the ink 71 travels through the ink cartridge 130 while passing through the ink 71. Then, the light reaches the infrared light absorbing member 131 provided in the sub ink storage chamber 45, and the infrared light is absorbed by the infrared light absorbing member 131. Therefore, the amount of reflected light received by the infrared light receiving element 19b of the ink sensor 19 is small (not more than a certain value).

Here, the inclined portion 51a is inclined at approximately 20 degrees with respect to the infrared light absorbing member 131, as in the first embodiment. Therefore, for example, even when the infrared light absorption characteristics of the infrared light absorbing member 131 deteriorate with time and reflect infrared light, the infrared light absorbing member 131
Is reflected in a direction different from the inclined portion 51a (that is, the optical path X), and the ink sensor 1
Thus, the amount of reflected light irrespective of the detection of the presence or absence of ink detected by the infrared light receiving element 19b can be suppressed.

On the other hand, when the ink 71 in the sub ink storage chamber 45 has been consumed, the red light emitted from the infrared light emitting element 19a of the ink sensor 19 is emitted as shown in FIG. The external light (optical path X) has a refractive index different from that of the material of the inclined portion 51a (prism 52) and that of air.
The light is reflected at the interface between the prism 52 and the air (optical path Y). Therefore, the amount of reflected light received by the infrared light receiving element 19b of the ink sensor 19 is large (a certain value or more).

As described above, according to the ink cartridge 130 of the second embodiment, the infrared light absorbing member 1
Since the infrared light irrelevant to the presence or absence of ink can be absorbed by 31, the amount of reflected light reflected from the inside of the ink cartridge 130 greatly changes according to the presence or absence of ink, and the difference in the amount of light Is detected using the infrared light receiving element 19b of the ink sensor 19,
It is possible to accurately detect the presence or absence of ink stored in the ink cartridge 130.

Since the inclined portion 51a (prism 52) and the infrared light absorbing member 131 are disposed above the sub ink storage chamber 45, all the ink 71 in the ink cartridge 130 is consumed. Beforehand, the presence or absence of ink can be determined with a margin.

The infrared absorbing member described above includes:
A publicly known publicly-known infrared absorbing member can be appropriately selected and used. For example, a glass material may be used as a base material and V (vanadium), Fe (iron), Cu (copper), Co (cobalt), Ni (nickel), or the like may be used alone or by mixing a plurality of types. . The base material is not limited to solids and liquids. The base material may contain an infrared absorbing agent such as an aliphatic dithiol metal complex. Further, a filter having a filter characteristic of absorbing a light wavelength in a specific region may be used.
It is desirable that the absorptivity of the infrared light is 90% or more.

The electrical configuration of the color inkjet printer 1 of the second embodiment is the same as that of the color inkjet printer 1 of the first embodiment shown in FIG. The processes executed by the color inkjet printer 1 are the same as the processes executed by the color inkjet printer 1 of the first embodiment shown in FIGS.

As described in the above embodiments, according to the image forming apparatus of the present invention, light is illuminated non-perpendicularly to the irradiated surface of the ink cartridge 2 and the amount of reflected light is detected by the optical detector. I do. Then, the detected amount of reflected light is compared with a threshold value for verifying the absence of ink and a threshold value for verifying that the ink cartridge is not mounted,
It can be verified that there is no ink and that no ink cartridge is installed. Therefore, based on the reflected light reflected from the ink cartridge 2, the presence or absence of the ink 71 and the presence or absence of the ink cartridge can be accurately detected.

Further, an error between the actual detected position of the ink cartridge 2 and the theoretical detected position is calculated, and based on the calculated error, when it is determined that there is no ink or the ink cartridge is not mounted, the carriage 5 is not used. Correct the position. Therefore, even if the detection position of the ink cartridge 2 by the ink sensor 19 is deviated from the original position due to the mounting error of the ink sensor 19, such deviation can be corrected, and the reflected light amount can be accurately detected. Can be.

In each of the above-mentioned embodiments, the test means according to the first aspect includes S16 in the flowchart of FIG.
And the processes of S43 and S46 in the flowchart of FIG. As the ink consumption counting means according to the third aspect, the processing of S12 in the flowchart of FIG.
The process of S22 corresponds. The processing of S14 in the flowchart of FIG. The processing of S15 in the flowchart of FIG. The processing of S20 in the flowchart of FIG. The processing of S14 to S18 in the flowchart of FIG. 8 corresponds to the predetermined amount counting means described in claim 5. The processing in steps S2 to S5 in the flowchart of FIG. The processing of S7 in the flowchart of FIG. 7 corresponds to the error calculating means described in claim 6. The processing of S31 to S33 in the flowchart of FIG. 9 corresponds to the correction executing means according to claim 6 and the position correcting means according to claim 8.

Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without changing the gist of the present invention. For example, in the first embodiment, the facing surface between the inclined portion 51a and the reflecting member 53 is substantially two.
Although the inclined portion 51a is formed in a state of being inclined so as to be inclined by 0 degrees, the present invention is not limited to this.
Instead of inclining the inclined portion 51a, the reflecting member 53 may be formed to be inclined. Even in such a case,
The same effects as in the first embodiment can be obtained.

In the first embodiment, the reflection member 5
3 is formed in a bag shape, and the air reaching the reflecting member 53 is reflected by filling the inside of the bag shape with air 72. However, if the light reaching the reflecting member 53 can be reflected, it is constituted by a reflecting plate. You may. The sub ink storage chamber 45
The reflection member 53 is separately provided in the main ink storage chamber 44.
The partition wall 42 that partitions the sub ink storage chamber 45 from the sub ink storage chamber 45 may be configured as the reflection member 53.

In the second embodiment, the inclined portion 51a to be irradiated with the infrared light is configured to be inclined with respect to the infrared light absorbing member 131. However, the inclined portion 51a and the infrared light You may comprise so that the absorption member 131 may become parallel. In other words, FIGS. 13A and 13B are side views of the ink cartridge 140 and the ink sensor 19, and as shown in FIGS. The ink cartridge 140 may be configured such that the infrared light absorbing member 141 and the side wall 51 (prism 52) are arranged in parallel. The principle of detecting the presence / absence of ink is the same as that described above, and will not be described. In this case, too, the infrared light absorbing member 141 is placed on the optical path X of the infrared light emitted from the infrared light emitting element 19a. By arranging, the presence or absence of ink can be detected with high accuracy.

Also, in the second embodiment, the partition wall 42
Alternatively, the foam 48 may be configured as an infrared light absorbing member. Further, the infrared light absorbing members 131 and 141 are the first
Reflection member 53 formed in bag shape shown in the embodiment
It may be stored inside. In this case, since the infrared light absorbing members 131 and 141 can be disposed in the ink cartridge in a state of being separated from the ink 71, for example, a material having poor ink resistance or a material having a bad influence on the ink. Thus, even a member made of is usable as a light absorbing member. Further, since the infrared light absorbing member can be sealed using the inside of the reflective member 53 formed in a bag shape, the infrared light absorbing member can be made of a liquid.

In each of the above embodiments, the color inkjet printer 1 is used as an image forming apparatus. However, the present invention is not limited to this.
The present invention can also be applied to an inkjet type copying machine, a facsimile machine, and the like. In addition, although four ink cartridges 2 are mounted on the color inkjet printer 1, one or more predetermined number of ink cartridges 2 may be mounted.

In each of the above-described embodiments, the correction value for correcting the deviation between the original detection position and the actual detection position in the calibration data input process is stored in one ink cartridge 2 serving as a reference. In the calibration process (S15), the calculated 1
The position of the ink cartridge 2 was corrected using the correction value of (1). However, instead of this, each ink cartridge 2
, Or the correction values of the ink cartridges 2 at both ends may be detected, and the position of the ink cartridge 2 may be corrected based on the detected correction values. Thereby, the reflected light from the ink cartridge 2 can be more accurately detected at the accurate detection position.

In each of the above embodiments, one counter (first to fourth counters 94b to 94e) is provided corresponding to one ink cartridge 2. Then, in the ink detection processing, the counter counts the ink detection intervals while the near empty flags 94f to 94f-9 are used.
4i are turned on, the first to fourth counters 94b to 94b to 94n corresponding to the turned-on near empty flags 94f to 94i.
The count value of 94e is cleared to 0, and the number of times of ink ejection is newly counted up to the empty threshold value. However, instead of this, two counters are provided corresponding to one ink cartridge, and in the ink detection process, the total number of ink ejections from the first time until the ink becomes empty is counted by the one counter,
The other counter may count the detection interval based on the number of ink ejections.

[0138]

According to the image forming apparatus of the first aspect,
Irradiate the non-perpendicular light to the irradiated surface of the ink cartridge,
The amount of reflected light is detected by an optical detector. Then, the detected amount of reflected light is compared with a threshold value for verifying that there is no ink and a threshold value for verifying that the ink cartridge is not mounted, respectively, to verify that there is no ink and that the ink cartridge is not mounted. Can be. Therefore, based on the reflected light reflected from the ink cartridge, there is an effect that the presence / absence of ink and the presence / absence of attachment of the ink cartridge can be accurately detected.

According to the image forming apparatus of the second aspect, in addition to the effect of the image forming apparatus of the first aspect, the verification means also detects the amount of reflected light detected at a predetermined position of the ink cartridge by the optical detector. A comparison is made between the threshold values stored in the first threshold value storage means and the second threshold value storage means to determine whether there is no ink and whether the ink cartridge is not mounted. Therefore, the presence / absence of ink and the presence / absence of ink cartridge mounting can be detected based on the amount of reflected light detected at a predetermined position, and there is an effect that such detection processing can be executed efficiently.

According to the image forming apparatus of the third aspect, in addition to the effects of the image forming apparatus of the first or second aspect, the ink consumption amount counted by the ink consumption amount counting means is reduced by a predetermined amount. Is reached, the amount of reflected light is detected by the optical detector. Therefore, there is an effect that the reflected light amount can be detected each time the consumption amount of the ink reaches the predetermined amount.

According to the image forming apparatus of the fourth aspect, in addition to the effect of the image forming apparatus of the third aspect, after the ink absence is inspected by the inspection means, the ink consumption is counted by the ink consumption amount counting means. Determine whether the ink cartridge is empty. Therefore, even if the amount of ink stored in the ink cartridge falls below the detection limit of the optical detector, the emptyness of the ink cartridge, that is, the ink empty, can be reliably detected by counting by the ink consumption counting means. There is.

According to the image forming apparatus of the fifth aspect, in addition to the effects of the image forming apparatus of the first or second aspect, the ink consumption is counted, and the counted ink consumption is determined. When the amount reaches the fixed amount, the detecting means detects the amount of reflected light so as to make the ink cartridge check that there is no ink, and includes a predetermined amount counting means for initializing the counting. Therefore, it is possible to determine the empty state of the ink cartridge by counting the ink consumption, and to count the predetermined amount of ink consumption by the predetermined amount counting means and determine the detection interval of the reflected light amount by the counting. effective.

According to the image forming apparatus of the sixth aspect, in addition to the effects of the image forming apparatus of the first aspect, the operation mode setting means adjusts the operation mode by the operation mode setting means. When the adjustment mode to be executed is set, an error between the measured ink cartridge detection position and the theoretical detection position is calculated, and based on the calculated error, there is no ink or the ink cartridge is not mounted. Is performed for detecting the amount of reflected light when the test is performed. Therefore, even if the positional relationship between the optical detector and the irradiated surface of the ink cartridge deviates from the original position due to a mounting error at the time of manufacturing, the deviation can be corrected and the amount of reflected light can be detected. Therefore, the amount of reflected light from the ink cartridge can be correctly detected, and the presence or absence of ink and the presence or absence of the ink cartridge can be reliably detected.

According to the image forming apparatus of the seventh aspect, in addition to the effect of the image forming apparatus of the sixth aspect, when measuring the detection position of the ink cartridge, the ink cartridge is moved at a lower speed than at the time of printing. Is moved to measure the detection position. Generally, printing is performed at high speed,
During printing, the carriage must also reciprocate at high speed. If the detection position is measured by moving the ink cartridge at such a speed, the detection of the reflected light amount must be rough sampling, and it becomes difficult to accurately measure the detection position. However, if the detection position of the ink cartridge is measured while moving the carriage at a speed lower than that at the time of printing, precise data sampling can be performed on the detection position. Therefore, there is an effect that the detection position of the ink cartridge can be accurately corrected by the obtained fine data.

According to the image forming apparatus of the eighth aspect, in addition to the effects of the image forming apparatus of the sixth or seventh aspect, when detecting the absence of ink or the absence of the ink cartridge, Position correction means for moving the carriage to a position taking into account the error stored in the error storage means is provided. Therefore, the amount of reflected light can be detected at an accurate position, and it is possible to accurately determine whether there is no ink or no ink cartridge is attached. Further, according to the correction of the detection position, there is an effect that parameters and comparison data can be easily set as compared with a case where the detected reflected light amount itself is electrically corrected.

According to the image forming apparatus of the ninth aspect, in addition to the effects of the image forming apparatus of any one of the first to eighth aspects, since a plurality of ink cartridges are mounted on the carriage, the color cartridge can be used. There is an effect that printing can be supported.

According to the image forming apparatus of the tenth aspect,
In addition to the effects of the image forming apparatus according to any one of claims 1 to 9, the light transmitted from the optical detector to the ink detection window of the ink cartridge is transmitted through the ink detection window as the ink cartridge. And an optical path changing member for changing the optical path of the light, and an ink cartridge having an ink detection window inclined at a predetermined angle with respect to the optical path changing member. Therefore, the optical path of the light transmitted into the ink storage chamber is changed by the optical path changing member to a direction in which the light is not received by the optical detector, and the light reflected in the ink storage chamber (reflected light irrelevant to the ink presence / absence detection) is changed. There is an effect that the optical detector can be prevented from receiving light. Therefore, reflected light having a large light amount difference can be obtained depending on the presence / absence of ink, and erroneous detection of presence / absence of ink can be prevented, thereby improving the detection accuracy.

According to the image forming apparatus of the eleventh aspect,
In addition to the effects of the image forming apparatus according to any one of claims 1 to 9, of the light emitted from the optical detector to the ink detection window of the ink cartridge as the ink cartridge, the light is transmitted into the ink storage chamber. An ink cartridge provided with an absorbing member for absorbing the light is used. Therefore, since the light transmitted into the ink storage chamber is absorbed by the light absorbing member, it is possible to prevent the optical detector from receiving light reflected in the ink storage chamber (reflected light not related to detection of the presence or absence of ink). There is an effect that can be. Therefore, reflected light having a large light amount difference can be obtained depending on the presence / absence of ink, and erroneous detection of presence / absence of ink can be prevented, thereby improving the detection accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view of a color inkjet printer to which an ink cartridge according to a first embodiment of the present invention is mounted.

FIG. 2 is a side view showing a state where the ink cartridge is mounted on a head unit.

3A is a side sectional view of the ink cartridge 2, FIG. 3B is a partial sectional view taken along line IIIb-IIIb of FIG. 3A, and FIG. It is a perspective view of a bottom part.

FIGS. 4A and 4B are diagrams schematically illustrating a vertical positional relationship between an ink cartridge and an ink sensor.

FIG. 5 is a diagram schematically illustrating a positional relationship between an ink cartridge and an ink sensor in a horizontal direction.

FIG. 6 is a block diagram schematically showing an electric circuit configuration of the color inkjet printer 1.

FIG. 7 is a diagram showing a flowchart of a calibration data input process which is one of the control programs.

FIG. 8 is a diagram illustrating a flowchart of an ink detection process for detecting ink.

FIG. 9 is a diagram showing a flowchart of a calibration process executed in the ink detection process of FIG. 8;

FIG. 10 is a diagram illustrating a flowchart of an ink cartridge detection process.

FIG. 11 is a diagram schematically illustrating a change in a reflected light level of the ink cartridge.

FIGS. 12A and 12B are side views of an ink cartridge and an ink sensor according to a second embodiment.

FIGS. 13A and 13B are side views of an ink cartridge and an ink sensor according to a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Color inkjet printer (image forming apparatus) 2 Ink cartridge 5 Carriage 19 Ink sensor (optical detector) 92 ROM (1st threshold value storage means, 2nd
Threshold storage means) 94a Calibration data memory (error storage means) 107a Mode switch (operation mode setting means) 41, 42 Partition wall (light absorbing member) 44 Main ink storage chamber (part of ink storage chamber) 45 Secondary Ink storage chamber (part of ink storage chamber) 48 Foam (porous material, light absorbing member) 51 Side wall (outer wall surface) 51a Inclined portion (ink detection window, part of outer wall surface) 53 Reflecting member (optical path changing member) 71 Ink 131, 141 Infrared light absorbing member (light absorbing member)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA29 EB07 EB11 EB20 EB36 EB44 EB49 EB52 EB59 EC11 EC31 EC35 FA10 KC01 KC04 KC09 KC10 KC11 KC13 KC16 KD06

Claims (11)

[Claims] An optical detector for irradiating an ink cartridge for storing ink with light and detecting a reflected light amount of the irradiated light, and an ink amount for storing the reflected light amount of the light irradiated from the optical detector. An image forming apparatus comprising: a detachable ink cartridge that can be changed according to the conditions described above; and a carriage that reciprocates with the ink cartridge mounted thereon, wherein the optical detector moves the carriage while moving the carriage. Irradiates the irradiation surface non-perpendicularly with light,
A first threshold value storage for detecting a reflected light amount of the non-vertically irradiated light, and storing a first threshold value for examining whether or not the detected reflected light amount indicates that there is no ink. Means, a second threshold value storage means for storing a second threshold value for testing whether or not the amount of reflected light indicates that the ink cartridge is not mounted, and a first threshold value storage means. A testing unit for comparing each threshold value stored in the second threshold value storage unit with the amount of reflected light to determine whether there is no ink or not mounted with the ink cartridge. Image forming apparatus. 2. The method according to claim 1, wherein the test means stores the amount of reflected light detected at a predetermined position of the ink cartridge by the optical detector in the first threshold storage means and the second threshold storage means. 2. The image forming apparatus according to claim 1, wherein a comparison is made between a threshold value and the absence of the ink cartridge to determine whether the ink cartridge is not mounted. 3. An ink consumption amount counting means for counting an ink consumption amount consumed from the ink cartridge, and judging whether or not the ink consumption amount counted by the ink consumption amount counting means has reached a predetermined amount. Determination means; and detection execution means for executing, when the determination means determines that the ink consumption amount has reached a predetermined amount, the optical detector to detect the amount of reflected light from the ink cartridge. Claim 1 or Claim 2
4. The image forming apparatus according to claim 1. 4. An empty judging means for judging whether or not the ink cartridge is empty, based on a count by the ink consumption amount counting means, after the test means judges that there is no ink. The image forming apparatus as described in the above. 5. An ink consumption amount is counted, and when the counted ink consumption amount reaches a predetermined amount, detection of a reflected light amount is performed to cause the verification means to verify that there is no ink in the ink cartridge. 3. The image forming apparatus according to claim 1, further comprising a predetermined amount counting unit that initializes the number. 6. An operation mode setting means for setting an operation mode, and detecting the ink cartridge by the optical detector when the operation mode is set to an adjustment mode for adjusting the apparatus by the operation mode setting means. Position measuring means for measuring the position; error calculating means for comparing the detected position of the ink cartridge measured by the position measuring means with a theoretical detected position to calculate an error; Error storage means for storing an error, and correction execution means for executing a correction relating to a detection position of the amount of reflected light at the time of testing whether there is no ink or not mounting the ink cartridge based on the error stored in the error storage means. The image forming apparatus according to claim 1, further comprising: 7. The apparatus according to claim 1, wherein said position measuring means moves said carriage at a lower speed than at the time of printing when measuring the detection position of said ink cartridge, and measures the detection position. The image forming apparatus according to claim 6. 8. The apparatus according to claim 1, wherein the correction execution unit includes a position correction unit that moves the carriage to a position that takes into account an error stored in the error storage unit when detecting the absence of ink or the absence of the ink cartridge. The image forming apparatus according to claim 6 or 7, wherein 9. The image forming apparatus according to claim 1, wherein a plurality of the ink cartridges are mounted on the carriage. 10. An ink storage chamber for storing ink, an ink detection window disposed on an outer wall surface of the ink storage chamber and having a light transmitting property through which light can pass, and a predetermined distance from the ink detection window. An optical path changing member disposed inside the ink storage chamber to change an optical path of light transmitted through the ink detecting window, wherein the ink detecting window is inclined at a predetermined angle with respect to the optical path changing member. The image forming apparatus according to claim 1, further comprising an ink cartridge as the ink cartridge. 11. An ink storage chamber for storing ink, an ink detection window disposed on an outer wall surface of the ink storage chamber and having a light transmitting property through which light can pass, and a predetermined distance from the ink detection window. 10. The ink cartridge according to claim 1, further comprising an ink cartridge provided inside the ink storage chamber and including a light absorbing member that absorbs light transmitted through the ink detection window. The image forming apparatus according to any one of the above.