JP2003063027A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder of a simple constitution capable of surely adjusting a received light amount of an ink sensor and precisely detecting an ink residual amount. SOLUTION: An ink cartridge storing yellow ink is moved to the light radiation position of the ink sensor (S22), where light radiation is conducted at a prescribed PWM value (S21) to read out an A/D conversion value based on a reflecting light amount (S23). When the A/D conversion value is larger than the first threshold value for detecting 'near empty' (S24: No), processing is repeated by increasing the PMW value (S25) until the A/D conversion value decreases less than the first threshold value. When the A/D conversion value decreases less than the first threshold value (S24: No), the value to be obtained by deducting one from the PMW value is stored in a memory as an adjusted value (S26).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a recording apparatus such as an ink jet printer which optically detects the presence or absence of ink stored in an ink cartridge by an optical detector.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer used as a recording device such as a printer, a facsimile, a copying machine, etc. is provided with an optical detector for optically detecting the presence or absence of ink stored in an ink cartridge. . This optical detector emits light from a light emitting element or the like toward an ink cartridge made of a light transmissive substance,
The amount of reflected (transmitted) light is detected by a light receiving element. Since the amount of reflected light from the ink cartridge changes depending on the presence or absence of ink, the presence or absence of ink can be optically detected by detecting the amount of reflected light from the ink cartridge.

However, since the ink sensor used for the detection has a variation in sensitivity, accurate detection cannot be performed when the light irradiation intensity is constant.

Therefore, conventionally, a process of adjusting the irradiation intensity of light is performed so that the amount of light received by the ink sensor is constant when the ink is sufficiently contained in the ink cartridge.

In this adjustment process, the drive of the light emitting element is controlled by P
This is performed by performing WM control, and is performed for each printer.

[0006]

However, since the amount of reflected light from the ink cartridge differs depending on the color of the ink stored in the ink cartridge, in a printer equipped with ink cartridges of a plurality of colors of ink, each ink cartridge is It is necessary to perform the adjustment process every time, resulting in complicated process and increased process time.

It is also conceivable to measure the amount of reflected light only for one ink cartridge and estimate the amount of reflected light for the other ink cartridges based on the measured value.

However, when this method is used, the amount of reflected light from the ink cartridge differs depending on the color of the ink contained therein, and it is difficult to estimate an appropriate adjustment value for other ink cartridges.

As a result, the ink remaining amount can be accurately detected for the ink cartridge whose reflected light amount has been actually measured, but the ink remaining amount can be accurately detected for the ink cartridge using the estimated value. You will not be able to do it.

The present invention has been made in order to solve the above-mentioned problems, and has a simple structure and is capable of reliably adjusting the amount of light received by the ink sensor and detecting the remaining amount of ink with high accuracy. The challenge is to provide.

[0011]

In order to solve the above-mentioned problems, an ink cartridge for storing ink and an optical device for irradiating the ink cartridge with light and detecting the amount of reflected light. A detector, a carriage that carries the ink cartridge and reciprocates, an irradiation intensity adjusting unit that adjusts the irradiation intensity of light of the optical detector, and the carriage is moved to a light irradiation position of the optical detector. An ink remaining amount detecting means for detecting an ink remaining amount based on the reflected light amount, wherein the irradiation intensity adjusting means has the ink cartridge mounted on the carriage, and at least the irradiated position with respect to the light in the ink cartridge. When the ink is stored up to, the ink with the highest brightness is stored in the ink cartridge. Results of the ink remaining amount detection of the ink remaining amount detecting means based on the amount of light reflected from the ink cartridge, so that the ink-present, and adjusting the irradiation intensity of light of the optical detector.

According to the recording apparatus of the first aspect, the irradiation intensity adjusting means irradiates the light when the ink cartridge is mounted on the carriage and the ink is stored at least up to the light irradiation position of the ink cartridge. Adjust strength. Specifically, of the ink cartridges, optical detection is performed so that the ink remaining amount detection result of the ink remaining amount detection means based on the amount of reflected light from the ink cartridge that stores the ink with the highest brightness indicates that ink is present. Adjust the irradiation intensity of light from the vessel. Therefore, when the remaining ink amount is detected by the light of the irradiation intensity after the adjustment, the state with ink is detected for the ink cartridge that stores the ink with the highest brightness,
With respect to other ink cartridges that store ink having a lightness lower than that, the presence of ink is reliably detected.

In order to solve the above problems, a recording apparatus according to a second aspect of the present invention is the recording apparatus according to the first aspect, further comprising position detection means for detecting the position of the carriage,
The irradiation intensity adjusting means recognizes the irradiation timing of light to the ink cartridge storing the ink having the highest brightness based on the position of the carriage detected by the position detecting means.

According to the recording apparatus of the second aspect, the irradiation intensity adjusting means irradiates the ink cartridge storing the ink having the highest lightness with light based on the position of the carriage detected by the position detecting means. That is, the irradiation intensity of the light from the optical detector is adjusted so that the result of the remaining ink amount detection by the remaining ink amount detection means based on the reflected light amount indicates that ink is present. Therefore, the irradiation intensity is surely adjusted for the ink cartridge that stores the ink having the highest brightness.

In order to solve the above-mentioned problems, a recording apparatus according to a third aspect of the present invention is the recording apparatus according to the first aspect, wherein the irradiation intensity adjusting means reads the amount of light reflected from each ink cartridge from the optical detector. The largest amount of reflected light is recognized as the amount of reflected light of the ink cartridge that stores the ink having the highest brightness.

According to the recording apparatus of the third aspect, the irradiation intensity adjusting means reads the amount of light reflected from each ink cartridge from the optical detector. As a result, the largest amount of reflected light is recognized as the amount of reflected light of the ink cartridge that stores the ink having the highest lightness, and the result of the remaining ink amount detection by the remaining ink amount detection means based on the reflected light amount is The irradiation intensity of the light of the optical detector is adjusted so that it is present. Therefore, the irradiation intensity is surely adjusted for the ink cartridge that stores the ink having the highest brightness.

In order to solve the above-mentioned problems, a recording apparatus according to a fourth aspect of the present invention is the recording apparatus according to any one of the first to third aspects, wherein the ink cartridge that stores the ink having the highest lightness is yellow. It is a cartridge for storing ink.

According to the recording apparatus of the fourth aspect, the irradiation intensity adjusting means determines that the result of the ink remaining amount detection by the ink remaining amount detecting means based on the reflected light amount from the ink cartridge storing the yellow ink is ink. The irradiation intensity of the light of the optical detector is adjusted so that it is present. Therefore, when the remaining ink amount is detected by the light of the irradiation intensity after the adjustment, the state where ink is present in the ink cartridge that stores the yellow ink is detected, so that the brightness is lower than that. With respect to the other ink cartridges that store the inks of color, the state with ink is surely detected.

In order to solve the above-mentioned problems, a recording apparatus according to a fifth aspect of the present invention is the recording apparatus according to any one of the first to fourth aspects, wherein the adjustment value of the light irradiation intensity by the irradiation intensity adjusting means is: It is characterized by being the only adjustment value effective for all ink cartridges.

According to the recording apparatus of the fifth aspect, the adjustment value obtained as a result of the adjustment of the irradiation intensity of the light by the irradiation intensity adjusting means as described above is the only effective value for all ink cartridges. It is used as an adjustment value for the subsequent detection of the remaining ink amount. Therefore, even when using an ink cartridge that stores a plurality of inks, accurate ink residual detection can be performed without complicating the process.

In order to solve the above-mentioned problems, a recording apparatus according to a sixth aspect of the present invention is the recording apparatus according to any one of the first to fifth aspects, wherein the ink cartridge has a main ink storage chamber and its main ink storage chamber. There is provided a sub-ink storage chamber in which ink is consumed after the ink in the chamber is consumed, and the irradiation intensity adjusting means irradiates light using an ink cartridge in which ink is stored only in the sub-ink storage chamber. It is characterized in that the strength is adjusted.

According to the recording apparatus of the sixth aspect, the ink cartridge in which the ink is stored in both the main ink storage chamber and the sub ink storage chamber, that is, the ink is not in a sufficient state, and the ink will be used soon. The irradiation intensity of the light is adjusted by the irradiation intensity adjusting means using the ink cartridge in this state. Therefore, more precise adjustment work is performed.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the present embodiment, a color inkjet printer capable of performing color printing will be described by using four ink cartridges 2 that store black, cyan, magenta, and yellow inks, respectively, as a recording device.

FIG. 1 is a perspective view showing the appearance of the main body of a color inkjet printer 1 according to the first embodiment of the present invention, FIG. 2 is a sectional view of the color inkjet printer 1 of FIG. 1, and FIG. 3 is a color inkjet printer of FIG. FIG. 3 is a perspective view showing a schematic configuration around a carriage and an ink cartridge in FIG.

As shown in FIGS. 2 and 3, the color ink jet printer 1 as the recording apparatus in the first embodiment includes an ink sensor 19 as an optical detector,
The amount of reflected light detected by the ink sensor 19 is compared with a threshold value to determine the presence or absence of ink. Particularly, in the first embodiment, the presence or absence of ink is determined during the paper feeding period, that is, during the period when the recording medium is newly conveyed to the recording position.

First, a schematic structure of the color ink jet printer 1 will be described. As shown in FIG. 3, the color inkjet printer 1 includes an ink cartridge 2 filled with four color inks of cyan, magenta, yellow, and black, and a recording medium P such as recording paper.
Head unit 4 having a print head 3 for printing on a carriage, 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 reciprocating movement of the carriage 5. Direction, the platen roller 7 arranged to face the print head 3, the purge device 8, and the ink sensor 1
9 and 9. Further, the color inkjet printer 1 is provided with a conveyance roller 200 as a recording medium feeding means, as shown in FIG.

As shown in FIG. 4, three partition plates 4c are erected on the mounting portion 4a of the head unit 4,
A pair of side covers 4b formed on both sides of the mounting portion 4a
And the mounting portion 4a is divided into mounting portions for the four ink cartridges 2 via the respective partition plates 4c. As shown in FIG. 3, the mounting portion is filled with black ink, cyan ink, magenta ink, and yellow ink 4
Two ink cartridges 2 (2a, 2b, 2c, 2d)
Is installed. The black ink cartridge 2
The fact that a has a large volume with respect to the ink cartridges 2b, 2c, 2d filled with the inks of the other three colors is because the frequency of use of the black ink is higher than that of the other colors. It is a thing.

Further, the head unit 4 is provided with a fixed arm 21 as shown in FIG. 4, and the fixed arm 21 fixes the ink cartridge 2 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 sealed by an O-ring 23 while being sealed by an O-ring 23. It is in communication with 50. Ink is supplied from the ink cartridge 2 to the print head 3 by such communication.

The drive unit 6 is arranged at the lower end of the carriage 5 and extends in parallel with the platen roller 7. A carriage plate 9 is arranged at the upper end of the carriage 5 and extends parallel to the carriage shaft 9, and the carriage thereof. Axis 9
And two guide plates 10, and two pulleys 11 and 12 arranged 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 backward by driving the carriage motor (CR motor) 101, the carriage 5 joined to the endless belt 13 is rotated along with the forward and reverse rotation of the pulley 11. The carriage is reciprocated in a linear direction along the carriage shaft 9 and the guide plate 10.

As shown in FIGS. 1 and 2, the recording medium P is placed on a paper feed tray 201 provided at the rear of the color ink jet printer 1 and is fed by the conveyance roller 200 shown in FIG. The recording medium P is conveyed in the direction of arrow A shown in FIG. 2 and introduced between the print head 3 and the platen roller 7. Therefore, when ink is ejected from the print head 3, predetermined printing is performed on the recording medium P. 1-pass printing is performed in the widthwise direction of the recording medium P within the nozzle forming range of the print head 3 in the direction of conveyance of the recording medium P and in the widthwise direction of the recording medium P in the direction of conveyance of the recording medium P. It is performed within the maximum printing range in. Therefore, every time one-pass printing is performed, the recording medium P is line-fed by the conveying roller 200 by the length corresponding to the nozzle forming range. Then, when the printing on the recording medium P is completed, the recording medium P is discharged by the conveying roller 200 and placed on the discharge tray shown in FIGS. 1 and 2.

The purging 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 purging device 8 includes a purging cap 14 that is in contact with the opening surface of the nozzles of the print head 3 so as to cover a plurality of nozzles (not shown), a pump 15, a cam 16, and an ink reservoir 17. When the head unit 4 is in the reset position, the nozzle of the print head 3 is 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. Thus, the print head 3 is recovered. The sucked defective ink is stored in the ink storage unit 17.

A wiper member 20 is disposed adjacent to the purging device 8 at a position on the platen roller 7 side of the purging device 8. The wiper member 20 is formed in a spatula shape, and wipes the nozzle forming surface of the print head 3 as the carriage 5 moves. The cap 18 is
In order to prevent the ink from drying, it 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 / absence of ink in the ink cartridge 2. It is provided near the end of the drive unit 6 (on the left side in FIG. 3) and includes an infrared light emitting element 19a and an infrared light receiving element 19b as shown in FIG. The light emitting surface of the infrared light emitting element 19a and the light receiving surface of the infrared light receiving element 19b are at an angle similar to that of the inclined portion 51a of the ink cartridge 2 which is inclined at about 20 degrees as shown in FIG. As shown in FIG. 7, they are arranged obliquely. The 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 ink in the ink cartridge 2 is detected based on the amount of the reflected light received.

Next, the internal structure of the ink cartridge 2 will be described with reference to FIG. 5A is a side sectional view of the ink cartridge 2, and FIG.
5 is a partial cross-sectional view taken along line IIIb-IIIb of FIG.
FIG. 3C is a perspective view of the bottom of the ink cartridge 2. Note that FIG. 5A illustrates a state in which ink is not stored in the ink cartridge 2.

As shown in FIG. 5 (a), the ink cartridge 2 is formed in a substantially hollow box-shaped body, and the inside of the ink cartridge 2 is defined by partition walls 41 and 42, and an atmosphere introduction chamber 43 is formed. , A main ink storage chamber 44 and a sub ink storage chamber 45. The atmosphere introducing chamber 43 communicates with the atmosphere into a main ink storage chamber 44 described later via an atmosphere communicating port 47. On the other hand, above the air introduction chamber 43 (see FIG.
The upper side of (a) is communicated with the main ink storage chamber 44, and the atmosphere is introduced into the main ink storage chamber 44 from the communication portion.

The main ink storage chamber 44 is a substantially sealed space for storing ink, and contains a foam (porous body) 48 that can be impregnated with ink.
Below the main ink storage chamber 44 (lower side in FIG. 5A),
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. Further, the foam 48 is made of a sponge, a fiber material, or the like capable of holding ink therein by utilizing the 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 may flow out from the main ink storage chamber 44 to the atmosphere introduction chamber 43, and the ink that has flowed out may leak out of the ink cartridge 2 through the air communication port 47. Can be prevented.

The sub ink storage chamber 45 is a portion for storing ink and is irradiated with infrared light from the ink sensor 19 shown in FIG. 4, and is substantially sealed at the side end portion of the ink cartridge 2. It is formed as an open space. The sub ink storage chamber 45 is communicated 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 is stored in the ink cartridge 2. It is supplied to the print head 3 shown in FIG. 2 through an ink supply port 50 formed through the bottom wall 46.

The side wall 51 of the sub ink storage chamber 45 is formed with an inclined portion 51a which is inclined downward toward the main ink storage chamber 44, and the inner surface side of the inclined portion 51a (on the side of the main ink storage chamber 44, FIG. On the left side of 5 (a), the prism 52
Are formed.

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

As shown in FIG. 5B, 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 end side (upper side in FIG. 5A) in the vertical direction of the inclined portion 51a toward the other end side (lower side in FIG. 5A), while They are arranged in the thickness direction (direction perpendicular to the paper surface of FIG. 5A). Therefore, since the ink can flow down on the prism 52, the prism 52
It is possible to prevent the ink from remaining on the top and prevent the desired reflected light from being obtained from the prism 52.

Thus, the prism 52 is attached to the inclined portion 51a.
7 is provided on the inner surface side (ink interface side, left side in FIG. 5B) of the infrared ray from the direction facing the inclined portion 51a non-perpendicularly (in this embodiment, the inclination angle is approximately 10 degrees).
Irradiation from the ink sensor 19 becomes possible as shown in FIG. As a result, it is possible to prevent the infrared light receiving element 19b from detecting the reflected light that is not related to the detection of the presence or absence of the ink reflected on the outer surface of the inclined surface 51a. Na prism 5
Since the reflected light from 2 is mainly received, the accuracy of the presence / absence detection of ink can be 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 infrared light beam spreads, and the amount of light per unit area with which the inclined portion 51a is irradiated decreases. Therefore, by disposing the prism 52 having a plurality of reflecting surfaces on the inclined portion 51a over almost the entire area of the inclined portion 51a, the irradiated infrared light can be efficiently received, and the infrared light of the ink sensor 19 can be received. Light receiving element 19
Sufficient reflected light can be received by b. In the prism 52 in the present embodiment, as shown in FIG. 5B, the intersection angle of the ridges where the reflecting surfaces intersect is approximately 90.
And 8 to 16 reflecting surfaces are formed.

Above the sub ink storage chamber 45, the reflecting member 5 which faces the above-mentioned prism 52 with a predetermined space therebetween.
3 is 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 has a bag shape having an air layer in its internal space while having a predetermined angle with the prism 52. Has been formed.

According to the ink cartridge 2 thus constructed, when ink is consumed by the print head 3, air is introduced from the atmosphere introduction chamber 43 into the main ink storage chamber 44 according to the amount of ink consumed. As a result, the ink liquid level in the main ink storage chamber 44 drops as shown in FIG. When the ink is further consumed and the ink in the main ink storage chamber 44 is used up, the ink in the sub ink storage chamber 45 is supplied to the print head 3. At this time, the inside of the sub ink storage chamber 45 is depressurized, but the air that has passed through the main ink storage chamber 44 from the atmosphere introduction chamber 43 is introduced into the sub ink storage chamber 45 through the ink communication port 49, and the sub ink storage chamber 45 is stored. The depressurization in the chamber 45 is relieved and the ink liquid level is
It decreases as shown in (b).

Therefore, the ink cartridge 2 is
The ink in the main ink storage chamber 44 is consumed, and after the ink in the main ink storage chamber 44 is completely consumed, the ink in the sub ink storage chamber 45 is consumed. Therefore, by detecting the presence / absence of ink in the sub ink storage chamber 45 by the ink sensor 19, it is possible to know the presence / absence of ink in the ink cartridge 2 as a whole.

Next, the principle of ink presence / absence detection will be described with reference to FIGS. 6 (a) and 6 (b). 6 (a) and 6 (b)
FIG. 3 is a side view of the ink cartridge 2 and the ink sensor 19, showing a part of the ink cartridge 2 in cross section. 6A and 6B, the head unit 4, the mounting member of the ink sensor 19 and the like are omitted and illustrated schematically.

When the ink 71 is sufficiently contained in the ink cartridge 2, the infrared light emitted from the infrared light emitting element 19a of the ink sensor 19 is (optical path X) as shown in FIG. 6A. Since the refractive index of the material of the ink cartridge 2 and the refractive index of the ink 71 are very close to each other, the ink 71 passes through the ink cartridge 2 while passing through the ink 71. And
It reaches the reflection member 53 disposed in the sub ink storage chamber 45. The infrared light reaching the reflecting member 53 is reflected at the interface between the inner surface of the reflecting member 53 and the air 72 (optical path Y) because the refractive index of the material of the reflecting member 53 and the refractive index of the air 72 are different.

Here, the inclined portion 5 of the ink cartridge 2
Since 1a is inclined by 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 of the inclined portion 51a. Therefore, the reflecting member 53
The reflected light (optical path Y) reflected by is reflected at an angle different from the incident light. Therefore, the reflected light (infrared light) does not go to the infrared light receiving element 19b of the ink sensor 19,
The amount of reflected light traveling toward 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, the infrared light emitting element 19a of the ink sensor 19 irradiates the ink 71 as shown in FIG. 6B. The infrared light is (optical path X),
Since the refractive index of the material of the ink cartridge 2 and the refractive index of air are different, the ink is reflected at the interface between the inner surface of the outer ink storage chamber 45 and the air (optical path Y). Therefore, the infrared light receiving element 19 of the ink sensor 19 is removed from within the ink cartridge 2.
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 ink cartridge 2 changes depending on the presence or absence of ink.
By using the infrared light receiving element 19b of No. 9, it is possible to detect the presence or absence of the ink stored in the ink cartridge 2.

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 preliminarily set at the time when the ink 71 does not exist above the sub ink storage chamber 45, that is, before all the ink 71 exists in the ink cartridge 2. You can judge that there is no.

Further, in this embodiment, the inclined portion 51
Although the inclination of a is about 20 degrees, it is not limited to such an angle, and may be in the range of about 15 degrees to about 25 degrees. That is, by setting the angle to 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 to set the angle to approximately 25 degrees or less, the ink is constantly stored in the inclined portion 51a. Can be suppressed.

Next, the ink sensor 19 is the surface to be irradiated with infrared light, and the inclined portion 51 of the ink cartridge 2 shown in FIG.
The reason why it is obliquely arranged at an angle of approximately 10 degrees with respect to a will be described with reference to FIG. 7. FIG. 7 is a top view showing the ink cartridge 2 and the ink sensor 19. The ink cartridges 2a to 2d mounted on the head unit 4 are reciprocally transported in the arrow W direction.

First, when the ink sensor 19 is arranged perpendicularly to the inclined portion 51a as shown in FIG. 7A, light emitted from the infrared light emitting element 19a (optical path X).
Transmits through the inclined portion 51a formed of a light transmissive member. However, incident light (optical path X) that should pass through the inclined portion 51a may be reflected by the adjacent ink cartridge 2c due to the fine irregularities on the outside of the inclined portion 51a, that is, the surface on the side opposite to the ink. 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 replaced by the one shown in FIG.
In the case where the infrared light receiving element 19b is inclined with respect to the inclined portion 51a as shown in FIG.
It is possible to suppress the light reflected by the surface outside the inclined portion 51a, that is, the surface on the side opposite to the ink, that is, the light indicated by the optical path Y in FIG. Therefore, when ink is present, as described with reference to FIG. 6, the light transmitted through the inclined portion 51a is not received, while when ink is absent,
The infrared light receiving element 19 receives the reflected light (optical path Y) from the inside of the inclined portion 51a, that is, the interface between the sub ink storage chamber 45 side and the air.
Light is received by b. Therefore, the presence / absence of ink can be accurately determined by the difference in the amount of light. Even if the ink cartridge 2c is not provided, the infrared light receiving element 1
Since the light emitted from 9a is not emitted to the adjacent ink cartridge 2d as indicated by the optical path X, the presence / absence of the ink cartridge 2c can be accurately determined.

In the present embodiment, the inclination of the ink sensor 19 with respect to the inclined portion 51a is set to about 10 degrees. However, this is the size of the ink cartridge 2, the gap between the ink cartridges 2, the ink cartridge. Two
Since the angle is determined by various factors such as the distance between the ink sensor 19 and the ink sensor 19, the angle is not limited to this angle as long as it has an inclination.

FIG. 8 shows a color ink jet printer 1.
3 is a block diagram showing an outline of the electric circuit configuration of FIG. The control device for controlling the color inkjet printer 1 includes a main body side control board 100 and a carriage board 120. The main body side control board 100 has a one-chip microcomputer (CPU) 91 and its CPU.
ROM 92 which stores various control programs executed by 91 and fixed value data, RAM 93 which is a memory for temporarily storing various data and the like, EEPROM 94 which is a rewritable non-volatile memory, image memory 95, a gate array 96, etc. are mounted. CPU91, ROM92, RAM93, EE
The PROM 94 and the gate array 96 are connected via an address bus 98 and a data bus 99.

The CPU 91 executes control of calibration data input processing, ink presence / absence detection processing, or ink cartridge presence / absence detection processing according to a control program stored in advance in the ROM 92. Also, a print timing signal and a set signal are generated, and each signal is transferred to a gate array 96 described later. The CPU 91 includes an operation panel 107 for a user to give a printing instruction, a motor drive circuit 102 for driving a carriage motor (CR motor) 101 for operating the carriage 5, and a conveyance for conveying the recording medium P. A conveyance motor (LF motor) 103 for driving the roller 200,
A motor drive circuit 104 for operating the carry motor (LF motor) 103, a paper sensor 105 for detecting the leading end of the recording medium (printing paper) P, an origin sensor 106 for detecting the origin position of the carriage 5, an ink sensor 19, and the like. It is connected. The operation of each connected device is controlled by this CPU 91.

The ROM 92 stores programs such as calibration data input processing and ink detection processing as a part of the control program. Details of each program will be described later. Also, as fixed value data,
A threshold value for detecting the absence of ink in the detected reflected light level, an empty threshold value that is the number of ink ejections until the ink level (the remaining amount of ink in the ink cartridge 2) changes from near empty to empty, and the like are stored. is doing.

The EEPROM 94 includes a first calibration data memory 94a-1, a second calibration data memory 94a-2, and first to fourth counters 94.
b to 94e and the first to fourth near empty flags 94f
~ 94i. The first calibration data memory 94a-1 stores the correction value obtained by the calibration data input process, that is, the ink cartridge 2
This is a memory for storing the positional deviation from the original detection position of as calibration data. Also,
The second calibration data memory 94a-2 absorbs the adjustment value of the light emission amount of the infrared light emitting element 19a obtained by the calibration data input process, that is, the variation of the infrared light receiving element 19b, and the presence or absence of ink. It is a memory for storing data for adjusting the output of the infrared light receiving element 19b according to the above so as to be constant in any printer.

As described above, in the color ink jet printer 1 of this embodiment, the ink sensor 19 is installed so as to be inclined with respect to the surface to be illuminated of the ink cartridge 2 at an angle of about 10 degrees. However, the angle is about 1 due to the mounting angle error that occurs when the sensor 19 is mounted.
It often does not reach 0 degrees. 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 cannot be accurately detected at the original detection position of the ink cartridge 2. Therefore, a deviation between the original detection position and the actual detection position is detected by the calibration data input process executed before shipment, and the deviation amount is used as a correction value in the first calibration data memory 94a-1. It is written in advance before shipping.

Since the sensitivity of the infrared light receiving element 19b varies from ink sensor to ink sensor, if the amount of light emitted from the infrared light emitting element 19a is kept constant, ink may be present in some cases. Regardless of the infrared light receiving element 19
The output of b may fall below the threshold value for detecting the absence of ink at the reflected light level, and it may be erroneously detected as the absence of ink. Therefore, in the present embodiment, in the calibration data input process, the yellow ink is stored in the yellow ink cartridge 2d having the highest brightness and the maximum reflected light amount (the ink is stored only in the sub ink storage chamber 45). The ink cartridge 2d in which the
The light emission amount of a is changed, and adjustment is performed so that the output of the infrared light receiving element 19b becomes a constant value indicating the presence of ink. Then, the value when the output of the infrared light receiving element 19b becomes a constant value indicating the presence of ink is written in advance in the second calibration data memory 94a-2 as an adjustment value before shipment.

When detecting the presence or absence of ink, the second
The infrared light emitting element 19a emits light based on the adjustment value stored in the calibration data memory 94a-2, and further, the first calibration data memory 9
The correction value stored in 4a-1 is referred to, and the detection position (carriage 5
Position) is adjusted. Accordingly, even if the positional relationship between the ink sensor 19 and the surface to be irradiated of the ink cartridge 2 is deviated from the original position, 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 ejection (ejection) from the print head 3. It is updated by "1" for each "1" of ink ejection times. A predetermined amount of ink is initially injected into the ink cartridge 2, but the maximum number of times of ejection is determined from the ink amount.
Therefore, it is possible to know the approximate consumption amount of the ink by counting the number of times the ink is ejected.

Since the color ink jet printer 1 is provided with four ink cartridges 2 for respectively storing inks of black, cyan, magenta and yellow, four counters (corresponding to each ink cartridge 2) First to fourth counters 94b to 94
e) is provided, and the first to fourth counters 94b to 94b correspond to the number of ink ejections counted for each ink.
94e is written. Then, the count values stored in the first to fourth counters 94b to 94e are referred to by the ink detection process, and the actual ink level (ink in the ink cartridge 2) is calculated every time the count value reaches a predetermined number. Ink detection processing by the ink sensor 19 is executed to detect the remaining amount.

A predetermined amount of ink is ejected from the ink cartridge 2 not only at the time of printing but also in the purging process for sucking out the air bubbles in the ink cartridge 2 and the flushing process for solving the clogging of the nozzle. . With respect to the ink consumed in this process, since it is known how many counts of the number of ejections at the time of printing, the corresponding count number is added to the previously stored count value, and the corresponding count value is added. 1 to 4 counter 9
The count values of 4b to 94e are updated.

First to fourth near empty flags 94f-
One of the flags 94i is provided for each of the four ink cartridges 2 for storing ink of each color of black, cyan, magenta, and yellow.
On of f to 94i indicates near empty of the ink. Here, near empty is the ink sensor 1
9 shows the detection limit of ink by No. 9, and shows the state in which the ink sensor 19 has detected that there is no ink.

As described with reference to FIGS. 5 and 6, 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 ink in the sub ink storage chamber 45 is removed. Consumed. When the ink surface of the sub ink storage chamber 45 falls below the lower portion of the reflecting member 53, the light emitted from the infrared light emitting element 19a of the ink sensor 19 is reflected by the prism 52 to the infrared light receiving element 1 of the ink sensor 19.
The light is reflected in the 9b 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 changes (increases). Since the detected reflected light amount is input to the CPU 91 as a signal, such a change is recognized as near empty by the CPU 91, and the corresponding near empty flags 94f to 94i are turned on.

The first to fourth near empty flags 9
4f to 94i are turned on, that is, the ink sensor 1
Since the ink in the ink cartridge 2 is not empty when it is detected by 9 that the ink is out,
Further, it is possible to continue printing until the ink is in the empty state, that is, until the number of ink ejections reaches the empty threshold.

In the present embodiment, when the first to fourth near empty flags 94f to 94i are turned on in order to accurately detect the emptyness, they are stored in the corresponding first to fourth counters 94b to 94e. The count value of 0 is cleared and the count value from 0 to the empty threshold is counted up to improve the accuracy of detecting the empty. The first to fourth near-empty flags 94f to 94i that are turned on correspond to the corresponding ink cartridge 2
However, the ink level is turned off when it is detected that the ink level is present, for example, by replacement.

The gate array 96 operates in accordance with the print timing signal transferred from the CPU 91 to the image memory 95.
Print data (drive signal) for printing the image data on a recording medium based on the image data stored in
And a transfer clock CLK synchronized with the print data,
The latch signal, the parameter signal for generating the basic print waveform signal, and the ejection timing signal JET output at a constant cycle are output, and these signals are transferred to the side of the carriage substrate 120 on which the head driver is mounted. Also,
The gate array 96 stores image data transferred from an external device such as a computer via the Centro interface 97 in the image memory 95. Then, the gate array 96 generates a centro data reception interrupt signal from the host computer or the like 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 is an infrared light emitting element 19
a and the infrared light receiving element 19b, the infrared light emitting element 1
Irradiation of infrared light from 9a to the ink cartridge 2 (see FIG.
Optical path X) and its reflected light (optical path Y in FIG. 6) are detected by the infrared light receiving element 19b which is a photo sensor. 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 detected as an electric signal corresponding to the amount of reflected light received. Since the detected signal is an analog signal, the infrared light receiving element 1
After being converted into a digital signal by the A / D converter 19c connected to 9b, it is input to the CPU 91. The amount of reflected light detected by the ink sensor 19 is compared with a threshold value in the ink detection process or the ink cartridge detection process. This makes it possible to know the presence or absence of ink. The A / D converter 19c converts the analog signal into a digital signal through steps such as sampling, quantization, and binary conversion.

FIG. 9 is a block diagram showing the drive circuit of the ink sensor 19 in detail. The drive circuit of the present embodiment includes the infrared light emitting element 19a and the infrared light receiving element 1 described above.
9b, A / D converter 19c and CPU 91, as shown in FIG. 9, an infrared light emitting element on / off transistor 19d connected to the CPU 91, an infrared light emitting element limiting resistor 19e, an infrared light receiving element. An element load resistor 19f and a low pass filter 19g are provided.

In this drive circuit, a PWM signal is supplied from the CPU 91 to the transistor 19d, the transistor 19d is turned on / off at a cycle of several kHz to several hundred kHz, and the infrared light emitting element 19a is turned on. Further, when the infrared light receiving element 19b receives the reflected light from the ink cartridge, the infrared light receiving element 19b receives the light according to the received light amount.
The amount of current flowing through b changes and the infrared light receiving element load resistance 1
The voltage drop value due to 9f changes. When the amount of received light is large, the voltage drop value is large, and when the amount of received light is small, the voltage drop value is small. Therefore, the voltage at the connection point between the infrared light receiving element load resistor 19f and the low-pass filter 19g changes in accordance with the change in the voltage drop value, and this change in voltage changes via the low-pass filter 19g to the A / D converter 19c. Is input to, converted to digital value and CP
Read by U91. Therefore, by changing the duty ratio of the PWM signal by the CPU 91, the light emission amount of the infrared light emitting element 19a can be adjusted and the output of the infrared light receiving element 19b can be adjusted.

The carriage substrate 120 is a substrate for driving the print head 3 by a mounted head driver (driving 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 includes a main body control board 10
The drive pulse is controlled through the gate array 96 mounted at 0, and a drive pulse having a waveform suitable for the recording mode is applied to each drive element. As a result, a predetermined amount of ink is ejected.

Next, with reference to the flow charts shown in FIGS. 10 to 12, the respective processes executed by the color ink jet printer 1 configured as described above will be described.

FIG. 10 is a flowchart of a calibration data input process which is one of the control programs. This calibration data input process is executed before shipping and is roughly divided into two processes. First, there is a process for detecting a positional deviation of the detection position of the ink cartridge 2 and storing the deviation amount as a correction amount in the first calibration data memory 94a-1. The other one absorbs the variation in the sensitivity of the ink sensor 19 and receives the infrared light receiving element 1 when ink is present.
9b is a process for adjusting the output of 9b to be constant regardless of the printer and storing the adjusted value in the second calibration data memory 94a-2. Hereinafter, the calibration data input process for storing the correction amount will be described as a first calibration data input process, and the calibration data input process for storing the adjustment value will be described as a second calibration data input process.

The first and second calibration data input processings 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.
First, it is confirmed whether or not the maintenance mode flag 93a is turned on (S1), and if it is not turned on (S1).
1: No), the calibration data input process is omitted. On the other hand, when the maintenance mode flag 93a is turned on (S1: Yes), the origin sensor 106 confirms that the carriage 5 is at the origin, and then the CR motor 101 is driven to move the carriage 5 a predetermined distance from the origin. As a result, the carriage 5 is moved to the home position (S2). Next, the infrared light emitting element 19a is turned on with a predetermined light amount (S3), and the carriage 5 is moved to the ink sensor 1
It moves at a low speed in 9 directions (S4). When the predetermined detection position is reached, that is, when the carriage 5 is moved by a predetermined distance from the origin, the ink sensor 19 starts detecting the reflected light amount, and the reflected light level (reflected light amount) reflected by the ink cartridge 2 is started. ) Is the infrared light receiving element 19b
Is received by the CPU 91 via the A / D converter 19c.
(S5). 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 range wider than the width of the carriage 5, and the reflected light level is as shown in FIGS. 13 (a) and 13 (b). , Detected by analog data.

As described above, the infrared light receiving element 1
The difference in the reflected light level received by 9b is caused not only by the presence or absence of ink but also by the presence or absence of the ink cartridge 2. However, the difference in reflected light level caused by the presence / absence of the ink cartridge 2 is smaller than the difference in reflected light level caused by the presence / absence of ink as shown in FIG.
Therefore, in the present embodiment, as shown in FIG.
The first threshold is used to detect the presence or absence of ink, and the second threshold is used to detect the presence or absence of the ink cartridge 2.

Then, the change position (theoretical value) from the theoretical level without ink cartridge to the level with the ink cartridge, which should be obtained originally (theoretical value), and the change position (actual value) detected in the process of step S6 shown in FIG. Deviation, that is, the deviation between the original detection position and the actual detection position is calculated as the carriage movement distance α, and the deviation is used as a correction value in the first calibration data memory 94a-
It is stored in 1 (S7). Here, the original detection position (theoretical value) is stored as the moving distance of the carriage 5 from the origin. Therefore, the actual detected position is the moving distance ± α of the theoretical value, and this ± α distance becomes the correction value.

The correction value stored in the first calibration data memory 94a-1 in the first calibration data input process is used in the calibration process executed in the ink detection process and the ink cartridge detection process. As a result, the detection position when detecting the reflected light from the ink cartridge 2 can be corrected and the reflected light level can be accurately detected.

Further, in the present embodiment, it is preset so as to pass the actual detection position and the theoretical detection position while the carriage 5 moves at a constant speed.
As shown in FIG. 15, the carriage 5 performs acceleration movement, constant speed movement, and deceleration movement after starting movement from the home position. Since the values of the acceleration and the constant velocity at this time are predetermined, whether or not the carriage 5 is moving in the constant velocity period can be known from the movement distance from the home position. Therefore, in this embodiment,
The actual detection position and the theoretical detection position are set so as to be the passing position within the constant speed period.

As a result of such setting, the light irradiation position on the ink cartridge 2 can always be kept constant, and the reflected light level can be detected more accurately.

In the present embodiment, the actual detection position and the theoretical detection position of the reference ink cartridge 2 are compared in the process of step S6, but the reference ink cartridge 2 is mounted on the carriage 5. Head ink cartridge 2 of the four ink cartridges 2
That is, the ink cartridge 2 reaches the detection position first.

When the first calibration data input process as described above is completed (S1 to S7), the ink sensor adjustment process which is the second calibration data input process is then performed (S8). The details of this ink sensor adjustment processing are shown in the flowchart of FIG.

In the ink sensor adjusting process, as shown in FIG. 11, first, the carriage 5 is moved to the home position (S20). Next, in the CPU 91, a value that determines the duty of the PWM signal supplied to the infrared light emitting element 19a is set to an initial value (a value that minimizes the amount of light emission) (S21). Next, the carriage 5 is moved so that the yellow cartridge 2d comes to the light irradiation position of the ink sensor 19 (S22). The positioning of the carriage 5 is performed by using an encoder (not shown). Then, the PWM signal set to the initial value as described above is supplied to the infrared light emitting element 19a, and the yellow cartridge 2d
From the infrared light receiving element 19b based on the amount of reflected light,
It is read as a value after A / D conversion (S23).

During this ink sensor adjustment processing,
Since ink is stored in all the ink cartridges (ink is stored only in the sub ink storage chamber 45 for at least the yellow ink cartridge 2d), the read waveform of the A / D conversion is, for example, as shown in FIG.
As shown in, the waveform has a waveform in which the voltage has dropped to a position close to the first threshold value. Note that FIG. 14 shows a waveform measured while moving the carriage 5 when the prism pitch is 2 mm. Also, in this example, the first threshold is 1.
It is set to 2V.

After reading the value after A / D conversion in step S23, whether the value is smaller than or equal to the target value, that is, the first threshold value, that is, is less than or equal to the first threshold value. A determination is made (S24). Then, when it is larger than the first threshold value (S24: No), the value for setting the duty ratio of the PWM signal is increased by 1 (S2).
5). If this value is increased by one, the transistor 19d
The ON period becomes longer, and the amount of light emitted from the infrared light emitting element 19a increases. Light emission is performed in this manner with the amount of light emission increased, and the output of the infrared light receiving element 19b is read again as a value after A / D conversion (S23), and that value is the target value, that is, the first threshold value. It is determined whether the value is less than or equal to the value (S24). Hereinafter, such processing is repeated until the value after A / D conversion becomes the first threshold value or less. Then, when the value after A / D conversion is smaller than or equal to the first threshold value (S24: Yes), the current PWM
A value obtained by subtracting one from the value for setting the duty ratio of the signal is stored in the second calibration data memory 94a-2 (S26).

By performing the adjustment process of the ink sensor as described above, even if the sensitivity of the ink sensor 19 varies, the output of the ink sensor 19 with respect to the ink cartridge in which the ink is fully stored does not depend on the printer. Can be constant.

Particularly, in the present embodiment, the adjustment is performed using the ink cartridge having the highest lightness and storing the yellow ink. Therefore, for the ink cartridges of other inks having a lower lightness than this, FIG. As shown, it is possible to reliably determine that ink is present.

The ink sensor adjustment process shown in FIG. 11 is not necessarily limited to this. For example, the PWM value that maximizes the light emission amount is set as the initial value in step S21, and then A The PWM value is increased by one until the value after A / D conversion exceeds the target value (first threshold value), and at the time when the value after A / D conversion exceeds the target value, the PWM value at that time May be stored in the second calibration data memory 94a-2.

Next, an ink detecting process, that is, a process of detecting the presence / absence of the ink 71 in the ink cartridge 2 will be described. The ink detection process of the present embodiment is performed with a new recording medium P.
Is a process executed during a period in which the sheet is supplied from the sheet tray 201 between the print head 3 and the platen roller 7, that is, in a sheet feeding period.

As shown in FIG. 16, when the printing process is started, the recording medium P placed on the paper tray 201 is printed.
Is fed by the transport roller 200, and the print head 3
And the platen roller 7 are conveyed. In the conventional printer, the movement operation of the carriage is not performed during the line feed period for this paper feeding. However, in the color inkjet printer 1 of the present embodiment, the carriage 5 is moved from the home position to the above-described detection position in order to execute the ink detection process during the paper feeding period. Then, the ink detection process described below is executed. Therefore, since the ink detection process is performed using the paper feed period, which is the stop period of the carriage 5 in the related art, there is no need to wait the printing operation only for the ink detection process as in the conventional case, and the color inkjet Ink presence / absence can be reliably detected while improving the processing speed of the printer 1.

In the present embodiment, when it is determined in the ink detection process during the paper feeding period that there is at least one printable amount of ink remaining in the ink cartridge 2 for printing. At the time of the ink detection processing, the warning of no ink is not issued, and the printing for one sheet of the recording medium P is completed. Then, after the printing is completed, a warning of no ink is given. With this configuration, the ink in the ink cartridge 2 can be effectively used, and the user can be appropriately warned that there is no ink.

Hereinafter, a specific example of the ink detection process will be described with reference to the flowchart of FIG. The ink detection process shown in FIG. 12 is executed in the paper feed period immediately after the start of printing and the paper feed period for each page.

In this ink detection process, first, the first to fourth near empty flags 94f of the ink cartridge 2 are firstly printed.
Confirm whether or not ~ 94i is turned on (S1)
3). As a result of confirmation, the first to fourth near empty plugs 9
If 4f to 94i are off (S13: No), the count value of the count values of the ink cartridges 2 corresponding to the off (flag off) first to fourth near empty flags 94f to 94i is It is confirmed whether or not there is a predetermined number d or more (S14). In this ink detection process, the presence / absence of ink is detected by the ink sensor 19 every time the number of times of ink ejection reaches a predetermined number d.

If the count value is greater than or equal to the predetermined number d (S14: Yes), the ink sensor 19 detects the presence or absence of ink (no ink) and the reflection at a predetermined detection position in consideration of the correction value. Light level (amount of reflected light)
A calibration process (sensor reading process) for capturing is performed (S15). After the execution of the calibration process (S15), it is determined whether the captured reflected light level is equal to or higher than the first threshold value (S1).
6). The first threshold value is a reflected light level for distinguishing the presence of ink and the absence of ink.

Then, as a result of the judgment in the process of step S16, if the reflected light level taken in is equal to or higher than the first threshold value (below the first threshold value in the value after A / D conversion shown in FIG. 14) ( (S16: Yes), the ink liquid level of the sub ink storage chamber 45 is below the lower portion of the reflecting member 53, and the ink level (the amount of ink remaining in the ink cartridge 2) is near empty ( Detected as no ink). Therefore, the first to fourth near-empty flags 94b to 94i of the corresponding ink cartridge 2 are turned on (S17), and the corresponding count value (the count value stored in the corresponding first to fourth counters 94b to 94e). ) Is set to 0 (S18). After that, other processes are executed (S19), and the ink detection process is ended.

On the other hand, as a result of checking in the process of step S13, if the first to fourth near empty flags 94f to 94i of the ink cartridge 2 are on (S13: Ye
s), the 1st to 4th of which is turned on (the flag is turned on)
It is confirmed whether or not the count value of the ink cartridge 2 corresponding to the near empty flags 94f to 94i is equal to or more than the empty threshold value (S20). The ink level of the ink cartridge 2 corresponding to the flag-on first to fourth near empty flags 94f to 94i is the ink sensor 19
Since the ink detection limit is exceeded, the ink empty is detected by counting the number of ink ejections after the near empty.

Here, if the confirmed count value is less than the empty threshold value (S20: No), there is still an ink remaining amount that can be used for printing.
After shifting to the process of 9 and executing each process (S19), this ink detection process is ended. Further, as a result of confirmation in the process of S20, the first to fourth near empty flags 9 which are turned on are detected.
If the count value of the ink cartridge 2 corresponding to 4f to 94i is equal to or more than the empty threshold value (S20: Y
es), an ink empty processing for displaying the ink empty is executed (S21). As described above, when it is determined that the printable amount is one sheet of the recording medium P, the ink empty is not displayed immediately, but is displayed after the printing is completed. After the process of S21 is performed, the process proceeds to the process of S19, and each process (S19) such as temporarily storing the data that could not be printed is performed, and then the ink detection process is terminated.

After the confirmation in S14, if there is no count value equal to or greater than the predetermined number d (S14: N
o), the process shifts to the process of S19 and each process (S1
After performing 9), this ink detection process is terminated.

Further, after confirming in the processing of S16, if the reflected light level 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 proceeds to the process of S18.

Although detailed description is omitted, in the present embodiment, the ink cartridge detection process is performed by the same method as the ink detection process. When it is determined by the ink cartridge detection process that the ink cartridge 2 has been replaced (attached or detached), the first to fourth counters 94b to 9 corresponding to the ink cartridge 2 are detected.
The count value of 4e is set to 0, and counting up of the number of ink ejections is started. However, the replaced ink cartridge 2 has a variation in the ink filling amount due to, for example, mounting of used parts and manufacturing variations.
Further, in consideration of variations in the amount of ink ejected from the print heads 3 of the respective color inkjet printers 1, the count values up to near empty are not necessarily the same. For this reason, if the count is continuously incremented from the initial state to the ink empty, it becomes difficult to judge the ink empty with a certain threshold value (predetermined count value), and it is detected with the predetermined count value. Incompleteness tends to be inaccurate. However, when near empty is detected,
Since it is considered that the ink remaining amount in the ink cartridge 2 is almost the same, it is considered that the number of times (count value) of ink ejection necessary to consume this ink remaining amount is also the same. Therefore, if a predetermined number near the number of discharges is set as the empty threshold, and the time when the near-empty state is detected (near empty flag is turned on) is set to 0 count, and if the empty threshold is counted up, the exhaust Can be detected.

As described above, according to the present embodiment, the light emission amount of the infrared light emitting element 19a in the ink sensor 19 is adjusted using the ink cartridge of yellow ink, so that the sensitivity of the ink sensor 19 varies. Even if there is, the remaining ink amount can be detected accurately.

Further, since the amount of reflected light of the yellow ink cartridge is the largest, if the amount of light emission is properly adjusted to detect the remaining ink amount in the yellow ink cartridge, the ink cartridges of other inks will be used. Then, it is possible to surely perform the proper ink level detection. Therefore, even when using multicolored ink,
It can be applied to all ink cartridges using only one adjustment value. As a result, the process is simplified and
The processing time can be shortened.

Moreover, by using the yellow ink cartridge in which the ink is stored only in the sub ink storage chamber 45,
Since the light emission amount of the infrared light emitting element 19a is adjusted, it is more difficult than the case of using an ink cartridge in which ink is stored in both the main ink storage chamber 44 and the sub ink storage chamber 45. Highly accurate adjustment can be performed under the conditions. That is, the ink cartridge in which the ink is stored only in the sub ink storage chamber 45 has a larger amount of light reflection than the ink cartridge in which the ink is stored in both the main ink storage chamber 44 and the sub ink storage chamber 45. Since the adjustment is performed under the condition closer to the level of no ink, the adjustment can be performed with higher accuracy.

In the present embodiment, the case where the position of the yellow ink cartridge is specified using the encoder has been described, but the present invention is not limited to such a configuration, and it is possible to detect the remaining amount of ink. As described above, the position of the yellow ink cartridge may be specified by reading the reflected light amount of each ink cartridge.

The ink detection process may be performed not only during the paper feed period but also during the line feed period during printing, and further during the paper discharge period.

Further, in the above embodiment, the ink sensor 1 is not activated after the count value of the ink cartridge becomes d or more.
Although the ink detection process by 9 is executed, the invention is not limited to this, and the ink detection process by the ink sensor 19 may be executed immediately after a new ink cartridge is replaced, for example. Is.

In each of the above embodiments, the color ink jet printer 1 is used as the recording device.
The present invention is not limited to this, and can be applied to, for example, an inkjet type copying machine or a facsimile machine. Further, although the four ink cartridges 2 are attached to the color inkjet printer 1, it may be configured to be attached with a predetermined number of one or more ink cartridges 2 containing a plurality of colors of ink.

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

[0114]

As described above, according to the present embodiment, since the light emission amount of the light emitting element in the ink sensor is adjusted by using the ink cartridge of the ink having the highest lightness, the sensitivity of the ink sensor varies. Even if there is, the remaining ink amount can be detected accurately. Moreover, since the adjustment is performed using the ink cartridge of the ink having the highest lightness, it is possible to surely perform the appropriate remaining ink amount detection for the ink cartridges of the other inks having lower lightness. Therefore, even when using multicolor inks, it is possible to apply to all ink cartridges by using only one adjustment value. As a result, the processing can be simplified and the processing time can be shortened.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a color inkjet printer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the color inkjet printer of FIG.

3 is a perspective view showing a schematic configuration around an ink cartridge and a carriage in the color inkjet printer of FIG.

FIG. 4 is a side view showing a state in which the ink cartridge is mounted on the head unit in the color inkjet printer of FIG.

5A is a side sectional view of the ink cartridge of FIG. 4, FIG. 5B is a partial sectional view taken along line IIIb-IIIb of FIG. 4A, and FIG. 5C is a sectional view of the ink cartridge 2 of FIG. It is a perspective view of a bottom part.

6A and 6B are diagrams schematically showing a vertical positional relationship between the ink cartridge of FIG. 4 and an ink sensor.

FIG. 7 is a diagram schematically showing a horizontal positional relationship between the ink cartridge of FIG. 4 and an ink sensor.

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

9 is a block diagram showing details of a drive circuit of an ink sensor in the electric circuit of FIG.

10 is a flowchart of a calibration data input process in the color inkjet printer of FIG.

11 is a flowchart of an ink sensor adjustment process in the color inkjet printer of FIG.

FIG. 12 is a flowchart of an ink detection process in the color inkjet printer of FIG.

13A and 13B are diagrams schematically showing changes in the reflected light level of the ink cartridge in the color inkjet printer of FIG.

14 is a diagram showing a reading waveform at the time of ink detection processing when ink is fully stored in each ink cartridge in the color inkjet printer of FIG.

FIG. 15 is a diagram showing a change in speed of the carriage of the color inkjet printer of FIG.

16 is a timing chart for explaining ink detection processing timing in the color inkjet printer of FIG.

[Explanation of symbols]

1 color inkjet printer 2 ink cartridge 2d yellow ink cartridge 5 carriage 19 ink sensor 91 CPU

Claims (6)

[Claims] 1. An ink cartridge that stores ink, an optical detector that irradiates the ink cartridge with light to detect the amount of reflected light, a carriage that carries the ink cartridge and reciprocates, and the optical detector. And an ink remaining amount detecting unit for moving the carriage to the light irradiation position of the optical detector and detecting the ink remaining amount based on the reflected light amount. When the ink cartridge is mounted on the carriage and the ink is stored at least up to the irradiation target position for the light in the ink cartridge, the irradiation intensity adjusting means has the highest brightness of the ink cartridge. Of the remaining ink amount based on the amount of reflected light from the ink cartridge storing the ink The results of the ink remaining amount detection of, so that there is ink,
The recording apparatus according to claim 1, wherein the irradiation intensity of light of the optical detector is adjusted. 2. A position detecting means for detecting the position of the carriage is further provided, and the irradiation intensity adjusting means stores the ink having the highest brightness based on the position of the carriage detected by the position detecting means. 2. The recording apparatus according to claim 1, wherein the timing of irradiating the ink cartridge with the light is recognized. 3. The irradiation intensity adjusting means reads the amount of reflected light from each ink cartridge from the optical detector, and the largest amount of reflected light is the amount of reflected light of the ink cartridge storing the ink having the highest brightness. The recording device according to claim 1, wherein the recording device is recognized. 4. The recording apparatus according to claim 1, wherein the ink cartridge which stores the ink having the highest brightness is a cartridge which stores yellow ink. 5. The adjustment value of the irradiation intensity of light by the irradiation intensity adjusting means is a unique adjustment value effective for all ink cartridges. Recording device. 6. The ink cartridge is provided with a main ink storage chamber and a sub ink storage chamber in which the ink in the main ink storage chamber is consumed and then the ink is consumed.
6. The recording apparatus according to claim 1, wherein the irradiation intensity of the light is adjusted by the irradiation intensity adjusting means using an ink cartridge in which ink is stored only in the sub ink storage chamber. .