JP3210190B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink end detecting device for detecting that ink in an ink storage container or the like has run out in an ink jet recording apparatus for performing recording by discharging ink, or to detecting the remaining amount of ink. The present invention relates to an apparatus for detecting a remaining amount state.

In particular, the present invention relates to a device and method for detecting the remaining amount of ink contained in an ink storage container comprising a plurality of storage members capable of communicating and storing ink in different states. It is about.

[0003]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine, a facsimile, or a recording device used as an output device of a composite electronic device or a workstation including a computer or a word processor is made of paper or plastic based on image information. It is configured to record an image on a recording medium such as a thin plate. Such recording apparatuses can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method.

An ink jet recording apparatus (ink jet recording apparatus) performs recording by discharging ink from a recording means (recording head) onto a recording medium, and has the following advantages. It is easy to make the recording means compact,
High-definition images can be recorded at a high speed, recording can be performed on plain paper without special processing, running costs are low, and noise is reduced due to the non-impact method. It is easy to record a color image using color inks.

[0005] In particular, an ink jet type recording means (recording head) for discharging ink by using thermal energy is composed of an electrothermal converter, an electrode, and a film formed on a substrate through a semiconductor manufacturing process such as etching, vapor deposition, or sputtering. By forming a liquid path wall, a top plate, and the like, a device having a liquid path arrangement (discharge port arrangement) with high density can be easily manufactured, and further downsizing can be achieved.

In an ink jet recording apparatus, an ink storage device such as an ink tank for storing ink to be supplied to a recording head is mounted on a predetermined fixed portion of the ink jet recording apparatus or mounted on a carriage together with the recording head. Sometimes. In the former case, an ink supply path such as an ink tube is provided between the recording head and the storage device so that the ink supply path follows the movement of the carriage. In the latter case, the ink supply path between the recording head and the storage device can be relatively short. Therefore, the configuration in which the ink storage device is mounted on the carriage can be said to be a configuration suitable for downsizing the inkjet recording device, simplifying the configuration, and the like.

In a configuration in which both the recording head and the ink storage device (ink tank) are mounted on the carriage, a configuration in which the recording head and the ink tank are integrally formed, or a configuration in which the recording head and the ink tank are separated from each other. There are configurations that can be mounted.

In the former configuration in which the recording head and the ink tank are integrally formed, when the ink in the ink tank runs out, the cartridge in which the ink tank and the recording head are integrated is replaced with a new one. Has become popular in recent years because of its easy handling.
Since the expensive head is replaced every time the ink runs out, the running cost increases.

In the latter configuration in which the recording head and the ink tank are separably mounted, only the ink tank storing the ink is replaced when the ink runs out, and the head itself has reached the end of its life. It can be replaced at times.

In normal use, it is generally impossible for the head to become unusable due to its life before the ink in the ink tank is used up. Therefore, the number of replacements for expensive heads is less than the number of replacements for ink tanks,
Running costs can be reduced. However, in a configuration in which the recording head and the ink tank are separably mounted, the connection between the ink tank and the recording head needs to be precisely manufactured so that ink does not leak.

Further, in a recording apparatus using an ink jet system, it is possible to satisfactorily supply ink corresponding to the amount of ink ejected from a recording head at the time of recording. An ink supply system without such is required.

The ink leakage from the discharge port is a problem peculiar to the field of ink jet recording, and in order to solve the problem, the pressure at the discharge port is generally set to a state lower than the atmospheric pressure. In the ink jet recording apparatus, a negative pressure generating mechanism is provided in the ink supply system in order to realize the above-described pressure state. The negative pressure here is a back pressure in the ink supply direction to the ejection port, and particularly means a pressure state in which the ejection port is lower than the atmospheric pressure as described above.

When the ink storage section is of a replaceable type, in addition to the above-mentioned problem, the ink storage section can be smoothly attached and detached, and at this time, there is no ink leakage and the like, and the ink is reliably supplied to the recording head. It is required to be able to supply.

One form of an ink container as an ink container used in the above-described ink jet recording apparatus is disclosed in Japanese Patent Application Laid-Open No. 63-87242 (hereinafter referred to as a first conventional example). This first conventional example shows a configuration of an ink jet recording cartridge in which a foaming material is disposed almost entirely in an ink container and provided with a plurality of ink ejection orifices.

In this ink container, a negative pressure is generated due to the capillary force of the foam for storing the ink in a porous medium such as a polyurethane foam, which is a foaming material, and the ink is retained (prevention of ink leakage from the ink container). Is possible.

However, in the first conventional example, since the foam is required almost entirely in the ink storage section, the filling amount of the ink is limited, and the amount of ink remaining without being used in the foam increases. There has been a problem that ink use efficiency is poor.

Japanese Patent Application Laid-Open No. 6-40043 proposes a technique for increasing the ink filling amount in such a configuration in which a foam material is disposed as a negative pressure generating member in the ink storing means. According to the present application, by using an ink storage container in which a negative pressure generating member storage section and an ink storage section for storing ink are separated, almost all of the ink can be used except for the ink that adheres to the wall surface in the ink storage section. In addition, the capacity of the ink storage container can be increased. Further, the stored negative pressure generating member prevents the ink from leaking from the recording head, and can maintain a stable ink supply performance for a long period of time.

In any of the various ink jet recording apparatuses as described above, it is desirable that the ink storage means be replaced at an appropriate time, and a structure for accurately detecting the amount of ink remaining in the ink storage means, It is necessary to provide a configuration for appropriately detecting the time at which the battery runs out.

When the ink in the ink storage means runs out during recording, the ejection means for ejecting ink from the recording head generates energy for ejection in the absence of ink. In particular, a so-called bubble jet method is provided in which thermal energy generating means such as an electrothermal conversion element is provided as an ejecting means, and thermal energy is applied to the ink, and the ink is ejected using pressure generated by a state change due to heat of the ink. In an ink jet recording apparatus,
Driving the thermal energy generating means in a state where there is no ink not only unnecessarily raises the temperature of the print head but also causes damage to the print head itself.

In an ink jet recording apparatus of the type in which ink is ejected by using a mechanical pressure generating means such as a piezo element as the ejection means, the ejection means is driven by driving the ejection means in a state where there is no ink. Pressure continues to be generated in the absence of a load, resulting in deterioration of the ejection means and reduction in durability.

Conventionally, as a structure for detecting that ink in an ink storage container or the like of an ink jet recording apparatus has run out (ink end), Japanese Patent Application Laid-Open No. 54-133733 is known.
Japanese Patent Application Publication No. Hei 1-1741 discloses a configuration for detecting the light transmitting state of an ink tank using an optical element as disclosed in
JP-A-65-194853 discloses a configuration for detecting by conduction of an electrode member as disclosed in Japanese Patent Application Laid-Open No. 65-195485, and counts the number of ejection pulses as disclosed in JP-A-59-194853 and estimates based on the used ink amount. A configuration (hereinafter, referred to as a dot count system) and the like are known.

[0022]

However, the conventional ink end detecting device (ink remaining amount detecting device) described above.
In a configuration in which a foam material is arranged as a negative pressure generating member in the above-described ink storing means, or in an ink storage container configuration in which a negative pressure generating member accommodating portion and an ink accommodating portion are separated, the ink remaining amount state is accurately determined. It was difficult to detect.

For example, of the above-mentioned prior arts, the one that detects the light transmitting state of the ink tank using an optical element and the one that detects the conduction of the electrode member are provided with a negative pressure generating member due to the structure of the ink storage container. It is difficult to detect that the ink in the stored ink tank has run out. Further, even if the state of remaining ink in only the ink storage unit is detected in a configuration in which the negative pressure generation member storage unit and the ink storage unit are separated, a considerable amount of ink still remains in the negative pressure generation member storage unit. It could only be applied to warnings that a certain reduction had occurred.

In the configuration in which the remaining amount is detected by the conduction of the electrode member, if the negative pressure generating member is pressed by the installation of the electrode, a desired negative pressure cannot be obtained, which adversely affects the ink supply. It can be.

Also, in the dot counting method, a large error occurs because the amount of discharge varies per unit discharge, the amount of initial injection of the ink tank varies, and the amount of use varies depending on the use environment. This error may reach nearly half of the total ink amount considering all errors such as errors for each device and the effects of the environment, etc., and as a result, a warning that the remaining amount has decreased or a stop of the recording device may be issued. In order to surely perform the operation before the ink is exhausted, it is necessary to perform the operation while leaving nearly half of the ink. When the warning or the stop is performed with such a large amount of ink remaining, the detection of the remaining amount is meaningless or the ink is wasted. If an attempt is made to accurately detect the remaining amount by the dot count method, the cost becomes extremely high. Further, with the increase in the capacity of the ink storage container, accurate detection of the remaining amount of ink has become more difficult.

The present invention has been made in view of the above-described drawbacks of the ink remaining amount detecting function in an ink tank containing a negative pressure generating member such as an absorbent or a foam material, and has been developed to provide an ink that can be detected with high accuracy and a desired amount of remaining ink. It is intended to realize a remaining amount detection function.

[0027]

SUMMARY OF THE INVENTION According to the present invention, there is provided an ink tank for storing inks of different colors, comprising a plurality of ink tanks containing ink absorbers, and an ink tank for discharging ink. A carriage capable of mounting an inkjet head having nozzles thereon, and scanning means for scanning the carriage, and recording by discharging ink of a plurality of colors supplied by a plurality of ink tanks from nozzles of the inkjet head. In the ink jet recording apparatus, the ink jet recording apparatus is provided with a plurality of ink tanks mounted on the carriage at positions corresponding to the ink absorbers, and irradiates light to the positions of the ink absorbers in the ink tanks. A sensor comprising a light-emitting element and a light-receiving element for detecting light; Detecting means for detecting a decrease in the remaining amount of ink in an ink tank, based on a result of detecting reflected light of light emitted by the light emitting element by the light receiving element in a state where the light emitting element is opposed to the light emitting element, Scanning the carriage by the scanning means to sequentially move the plurality of ink tanks mounted on the carriage to a position facing the sensor, and detecting the decrease in the remaining ink amount of each of the plurality of ink tanks by the detecting means The detecting means may be configured such that the amount of light received by the light receiving element becomes smaller than a predetermined value due to a change in the reflectance of the wall surface inside the ink tank caused by a difference in the refractive index between the ink tank and the ink, and scattering of light by the ink absorber. It is characterized in that when it becomes larger, it is detected that the remaining amount of ink in the ink tank has decreased.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG.
1 is a schematic perspective view of an embodiment of an ink jet recording apparatus to which the present invention is applied to the ink tank and the ink jet recording apparatus proposed in Japanese Patent No. 40043.

In FIG. 4, reference numeral 8 denotes a chassis on which various components are mounted. Reference numeral 9 denotes a paper feed roller provided in the longitudinal direction of the apparatus and for conveying a recording paper (not shown). Reference numeral 10 denotes a paper feed roller provided in parallel with the paper feed roller 9 to feed the recording paper. Is a pinch roller for pressing the sheet. Reference numeral 2 denotes a guide shaft which is provided in parallel with the paper feed roller 9 and reference numeral 11 denotes a scale portion of a magnetic linear encoder which is provided in parallel with the guide shaft 2.

Reference numeral 1 denotes a carriage that moves along the guide shaft 2. Reference numeral 12 denotes a head cover for fixing an ink jet head (not shown) to the carriage 1, and 13 denotes a flexible substrate, which sends a recording data signal from the apparatus control unit to the ink jet head mounted on the carriage 1, An output signal from a sensor (not shown) of the provided magnetic linear encoder can be sent to the device control unit.

3 is provided in parallel with the guide shaft 2,
A support shaft that maintains the posture of the carriage 1 that is provided rotatably about the guide shaft 2,
Reference numeral 14 denotes a carriage motor for scanning the carriage 1 along the guide shaft 2, and reference numeral 15 denotes a timing belt for transmitting the driving force of the carriage motor 14 to the carriage 1. Reference numeral 16 denotes a transmission type photo interrupter provided in the scanning area of the carriage 1 for setting a reference position in the scanning of the carriage 1.

Reference numeral 17 denotes a suction cap used for preventing ejection failure of the ink-jet head or recovering the same, and reference numeral 18 denotes drying the inside of the ejection port (hereinafter also referred to as a nozzle) of the ink-jet head while the ink-jet head is on standby. It is a protective cap to prevent. Reference numeral 5 denotes a paper position switching lever provided on the carriage 1 for switching the clearance between the recording paper and the ink jet head according to the thickness of the recording paper. Reference numeral 6 denotes a paper position switching lever provided near the home position of the carriage 1. A reflection type photo interrupter 19 as an ink sensor is provided to prevent clogging of a nozzle portion of the inkjet head.
This is a preliminary ejection hole for receiving ink droplets when performing preliminary ejection prior to printing.

FIG. 1 is a side view of the carriage 1, FIG. 2 is a view showing a state in which the ink tank is mounted in FIG. 1, and FIG. 3 is a view of the carriage shown in FIG. 1 viewed from the direction of arrow A in FIG. It is a figure showing a state.

The positional relationship between the carriage 1 and the photo-interrupter 6 and the principle of detection by the photo-interrupter 6 will be described with reference to FIGS. 1, 2 and 3.

In FIGS. 1, 2 and 3, reference numeral 1b denotes a hole provided on the bottom of the carriage 1 for transmitting light from the photo interrupter 6.

In FIG. 2, reference numeral 21 denotes a nozzle 2 at the tip thereof.
2 is a print head for performing printing by discharging ink from the print head 2. 7 is an ink tank mounted on the carriage 1, 7a is an absorber as a negative pressure generating member provided in the ink tank, 7b is a boundary between the absorber in the ink tank and an outer wall 7e of the ink tank, 7c is a state in which the ink is not mixed with other members in the ink tank (hereinafter, referred to as a state below).
An ink storage portion (hereinafter, also referred to as a raw ink storage portion) 7d for storing with the raw ink is a boundary portion between the raw ink in the ink tank and the ink tank outer wall 7e. The material of the ink tank 7 is transparent to the detection light of the photo interrupter 6, such as transparent plastic. 24
Are supply ports for supplying ink to the print head 21;
Reference numeral 8 denotes an air communication port for performing gas-liquid exchange accompanying consumption of ink.

The head 21 and the ink tank 7 are integrally mounted on the carriage 1 and scan the shafts 2 and 3 in the vertical direction in the drawing.

FIG. 5 is a plan view of the substrate on which the photo interrupter 6 is mounted, where 6c denotes a light emitting unit and 6d denotes a light receiving unit. In FIG. 1, reference numeral 6a denotes an optical path (hereinafter, also referred to as a return optical path) in which the light 6b emitted from the light emitting section 6c is reflected and returned, and is received by the light receiving section 6d shown in FIG. This optical path may be a reflection surface in the plane of FIG. 1 as shown in FIG. 1, or a reflection plane may be a plane perpendicular to the plane of FIG. However, when the posture of the carriage 1 is largely changed by the operation of the above-described paper position switching lever 5, the influence of the posture difference is less likely to be obtained by setting the reflection surface in the direction perpendicular to the paper surface of FIG. Also, in FIG. 1, this optical path is drawn as a simple straight line so as not to complicate the drawing, but is actually a light beam having a certain spread.

The photo-interrupter 6 is installed so as to irradiate the detection light to a portion of the absorber 7a in the ink tank 7 slightly closer to the raw ink storage portion 7c. This position affects the remaining number of printable sheets at the time of detection as described later. Regarding the position of the photo-interrupter 6 in the height direction, it is desirable to arrange the photo-interrupter 6 such that the boundary 7b between the wall surface of the ink tank 7 and the absorber 7a comes near the focal position of the photo-interrupter 6. If the detection light deviates from the focus position of the photo interrupter 6, the spread of the detection light increases, and the S / N of the detection is lowered due to the light reflected and scattered at the edge of the hole 1b of the carriage 1 or the like. .

In this embodiment, as shown in FIG. 4, a color ink jet recording apparatus configured to be capable of discharging a plurality of different color inks will be described as an example. A plurality of inks of different colors are stored in corresponding ink tanks and mounted on a carriage. Therefore, the ink absorbed by the absorber 7a is one of the four colors of black, cyan, magenta, and yellow that are usually used in a color printer. After the ink flows sequentially from the absorber 7a through the supply port 24 and the flow path 30 in the print head 21, the heat energy is applied by a heat generating means (hereinafter also referred to as a heater) 31 provided in the nozzle 22 as a discharging means, and the energy is rapidly increased. The application of sufficient thermal energy causes the ink to foam and be discharged from the discharge port at the tip of the nozzle 22. Printing is performed by the ink thus ejected adhering to a medium such as paper.

As described above, the photo interrupter 6 is formed by integrating the LED, which is the light emitting element 6c of the light source, and the light receiving element 6d. This LED is an infrared light having a transmittance to any of the four color inks.
d also has sufficient sensitivity to the wavelength of the LED.

The photo-interrupter 6 is provided separately from the carriage 1, and irradiates infrared light to the bottom surface of the absorber 7a through a hole 1b opened in the carriage 1 and a wall 7e of the transparent ink tank 7, and reflects the infrared light. The detected light is detected by the light receiving element 6d. By disposing the photo-interrupter 6 as the detection system separately from the carriage in this way, a power supply line and a signal line from the main body of the recording apparatus to the carriage, which is a movable portion, become unnecessary, and the configuration is simplified. And cost reduction can be achieved.

FIG. 6 is an enlarged view of the vicinity of the photo-interrupter 6 of the photo-interrupter 6 on the lower surface of the absorber 7a when the ink tank 7 is sufficiently filled with ink, and FIG.
FIG. 4 is an enlarged view when ink runs out at the same position.
FIG. 8 is a graph showing a change in the output of the light receiving unit 6d of the photo interrupter 6 according to the remaining ink amount.

Next, the principle of detecting the remaining amount of ink according to the present invention will be described.

In general, Fresnel's formula indicating the amplitude reflectance of light at the interface between the media 1 and 2 having different refractive indices is:

[0047]

[Outside 1] Becomes

Where n1 is the refractive index of the medium 1 n2 is the refractive index of the medium 2 θ1 is the angle between the light rays in the medium 1 and the normal line θ2 is the angle between the light rays in the medium 2 and the normal line Has a relationship of n1 · sin θ1 = n2 · sin θ2.)

In this embodiment, if the light from the light emitting section 6c of the photo interrupter 6 is incident on the ink tank 7 at an angle nearly perpendicular, it can be considered that cos θ = 1, and Squared to describe with energy reflectivity instead of

[0050]

[Outside 2] Becomes

First, when there is sufficient ink in the ink tank 7, the gap between the wall 7e of the ink tank 7 and the absorber 7a is filled with ink as shown in FIG. Ink tank 7
The absorber 7a is plastic and has a refractive index of about 1.5 and ink has a refractive index of about 1.4, so that the reflectance on the inner wall of the ink tank 7 and the surface of the absorber 7a is only about 0.1% from the above formula. .

Next, as the ink is consumed, air enters into the gap between the wall surface 7e of the ink tank 7 and the absorber 7a through the air communication port 8 in FIG. 6 as shown in FIG. Tank inner wall and absorber 7 with no ink
The reflectance on the a surface is about 4%. That is, when the ink runs out, the amount of reflected light increases about 40 times. (However, the output difference is not actually detected due to the influence of light other than the reflected light from the boundary 7c such as the reflected light from the bottom surface outside the ink tank 7 or electric noise.)

Here, even if detection is performed at the boundary 7d between the ink tank 7 and the raw ink storage section 7c by the photo interrupter 6, a difference in reflectance occurs. There are the following differences.

[0054]

[Table 1]

As described above, when the detection is performed by the absorber portion, the number of the reflection elements is three times as large, and the amount of reflected light itself is correspondingly increased.

As shown in FIG. 7, air that has entered between the absorber 7a and the ink tank 7 often exists as many fine bubbles while passing through the absorber 7a. The reflected light amount further increases due to the scattering effect.

As described above, these reflectances are represented by cos θ =
The value is 1 in the case of 1. However, in other cases, there is a considerable difference in reflectance with and without ink. In either case, a large output difference occurs in the light receiving portion 6d of the photointerrupter 6 in accordance with the reflectance difference, so that the presence or absence of ink in the ink tank 7 can be detected based on the output difference.

Actually, the area where the photointerrupter 6 irradiates light is not a point even at its focal position.
It has a certain size, and the output of the photointerrupter 6 changes continuously as the ink gradually escapes from that area.

In FIG. 8, the abscissa represents the remaining number of printable sheets until the ink is exhausted and the ejection fails, and the ordinate represents the output of the photointerrupter 6. Based on this output change curve, when the threshold level is exceeded (in FIG. 8, the remaining amount capable of printing about 15 remaining sheets is set as the threshold), the amount of ink in the ink tank 7 decreases. Judge that Then, by turning on a warning display LED or the like on the display panel of the ink jet printing apparatus main body, it is possible to inform the user that the remaining amount of ink is low.

The remaining number of sheets for indicating that the remaining ink amount is low can be increased or decreased by changing the threshold level. However, as can be seen from FIG. 8, it is difficult to display the number before the output rises (about 30 remaining in FIG. 8). In response to this, the number of printable sheets when the output rises can be changed by changing the position where the photo interrupter 6 performs detection. In this way, a warning can be issued with a desired remaining number.

Alternatively, in order to surely prevent a printing failure from occurring, the printing operation may be stopped instead of or simultaneously with the warning. In this case, there is an effect that a stronger warning is given by temporarily stopping.

As described in detail above, according to this embodiment,
The reflected light of the light emitted from the light emitting unit 6c is detected by the light receiving unit 6d with respect to the ink tank 7 in which the absorber 7a is disposed as a negative pressure generating member, and the remaining ink in the ink tank 7 is detected based on the output level. It can be detected that the amount has become smaller than the predetermined amount.

At this time, the absorber 7a functions as a negative pressure control member for controlling the negative pressure of the ink supplied from the ink tank 7, and a reflection control member for controlling the amount of reflection of the light emitted by the light emitting section 6c. , It is possible to accurately detect a decrease in the remaining amount of ink in the ink tank in which the absorber 7a is disposed.

Further, this embodiment is applied to a color printer as described above, and four ink tanks 7 are arranged side by side corresponding to four colors. Therefore, by moving the carriage 1, the ink tanks of each color are sequentially made to face the photointerrupter 6, and the remaining ink amount of each ink tank is detected. Since it is necessary to individually track output changes in each color, a memory means corresponding to the output change is provided. In this case, it is desirable that the indication that the amount of remaining ink is low is displayed separately for each of the four colors. However, only one color is simply reduced because the display panel of the ink jet recording apparatus becomes complicated. May be displayed.

According to the configuration described above, the remaining amount of ink in each of the four color ink tanks can be accurately detected by one detection system with respect to the ink tank containing the ink absorber of the color ink jet recording apparatus.

In this embodiment, the detection is performed from the bottom of the ink tank 7. However, the present invention is not limited to the configuration in which the detection is performed from the bottom surface of the ink tank 7, and the detection may be performed from the side surface or the upper surface.

However, for the following reason, the ink tank 7
It is more desirable to perform detection from the bottom surface.

The density distribution of the absorber 7a is usually not uniform, and the ink escapes in a spot as the ink runs out. Therefore, even if there is still ink in the surroundings, only the place where the photo interrupter 6 happens to detect the ink is exhausted first, or vice versa. The number of sheets varies, and in the worst case, the ink may run out without warning.

However, since the bottom surface of the ink tank 7 is apt to accumulate ink due to the effect of gravity, the absorber 7a
The effect of the density distribution is reduced. Therefore, by performing detection from the bottom surface of the ink tank 7, it is possible to detect the remaining amount of ink with high accuracy.

(Second Embodiment) As described above, in the configuration shown in the first embodiment, it may be difficult to perform accurate detection due to the non-uniform density of the absorber 7a. FIG. 9 shows a second embodiment of the present invention in which another measure for the non-uniformity of the density of the absorber 7a described in the first embodiment is taken.

In FIG. 9, the same components as those in FIG. 6 are denoted by the same reference numerals. Reference numeral 6 'denotes a photo interrupter arranged as a second ink sensor, which is the same as the photo interrupter 6. In this embodiment, the photointerrupter 6 is also referred to as a first photointerrupter for convenience of explanation.

In the first embodiment, the remaining amount of ink is determined only from the output of the photointerrupter 6, but in this embodiment, the average value of the outputs of the first and second photointerrupters 6 'is calculated. To detect that the remaining amount of ink has decreased. This average value may be a simple average or a weighted average. In this embodiment, since the second photo interrupter 6 'is closer to the supply port 24 than the first photo interrupter 6, the output changes after the number of remaining printable sheets becomes smaller. Therefore, which weight is to be determined more depends on the remaining number of sheets to be detected.

As described above, by providing sensors for detecting the remaining amount of ink at a plurality of points and using the average value of the measured values at the plurality of detection points, even if the density of the absorber 7a is not uniform, the influence is not affected. Thus, the remaining amount can be detected with high accuracy.

As means for reducing the variation in the detected value due to the influence of the non-uniformity of the density of the absorber 7a, FIG.
It is also conceivable to make the photointerrupter 6 movable as described in, and to detect the remaining amount of ink at a plurality of points in the ink tank.

Further, the present invention is not limited to the example in which the photo interrupter 6 is configured to be movable, and a plurality of points may be measured while the carriage 1 is moved while the photo interrupter 6 is fixed. However, in this case, if the ink tank 7 does not have a certain thickness in the moving direction of the carriage 1, the effect achieved by increasing the number of detection points is small.

In this embodiment, the remaining amount of ink is detected at a plurality of points while the photointerrupter 6 and the carriage 1 are relatively moved, and the average value of the measured values at the plurality of detection points is used. The absorber 7a as described above
Even if the density is uneven, the effect can be reduced, and the remaining amount can be detected with high accuracy.

(Third Embodiment) In the first embodiment, when the output of the photointerrupter 6 exceeds a predetermined threshold value, a warning or a stop of the printing operation is performed.

In this embodiment, when the output of the sensor exceeds the threshold value, no warning or stop of the printing operation is performed, and instead, a display corresponding to the output of the photo interrupter 6, that is, the output of the photo interrupter 6 is displayed. A display that changes proportionally or monotonically is performed.

As is apparent from FIG. 8, the ink tank 7
The output of the photointerrupter 6 changes continuously as the remaining ink amount in the inside decreases. Therefore, by displaying the remaining amount corresponding to the output change, it is possible to continuously perform display substantially corresponding to the remaining number of printable sheets. By doing so, more detailed ink remaining amount information can be given to the user.

FIG. 10 shows an example in which the remaining amount of ink in the ink tank 7 is displayed on the display panel. As shown in FIG. 10, the display on the display panel may change the level of the digital meter in accordance with the remaining number of printable sheets, or may display the remaining number of printable sheets by numbers.
Further, as the display panel, generally used display devices such as those using liquid crystal may be used.

The present invention is not limited to the display means to be visually recognized, but may be a method of guiding the remaining printable number by voice or a method of changing the length and the number of times of the buzzer sound according to the remaining printable number.

With the above configuration, the photo interrupter 6
, It is possible to inform the user of detailed ink remaining amount information. According to the present embodiment, when the remaining amount of ink in the ink tank 7 has decreased, the user can know the detailed remaining amount of ink, and can perform maintenance such as replacement of the ink tank at an appropriate time.

(Fourth Embodiment) In the first embodiment described above, the ink tank 7 includes the absorber 7a and the raw ink storage 7
However, the present invention is not limited to this configuration, and is also applicable to an ink tank having a configuration as shown in FIG.

The ink tank shown in FIG. 11 has an absorber 7a arranged over the whole area of the ink tank 7.

In FIG. 11, similarly to FIG. 2, 24 is a supply port, 28 is an air communication port, and 6 is a photo interrupter as a photo interrupter. Photo interrupter 6
Is arranged to detect a change in the reflectance of the bottom surface of the absorber 7a as in the first embodiment.

(Fifth Embodiment) According to the present invention, when there is no ink tank 7, the reflected light from the photointerrupter 6 disappears, so that the output level is much lower than the output level when there is sufficient ink. Become.

In this embodiment, the presence or absence of the ink tank 7 is determined by the photo interrupter 6, utilizing the configuration of the ink remaining amount detection shown in the first embodiment.

Using the photo interrupter 6, the presence or absence of the ink tank 7 can also be detected from the detection level difference between when the ink tank 7 is mounted and when it is not mounted.

Further, in this embodiment, the presence or absence of the ink tank of each color in the case of a color printer can be individually detected, and the recording is not performed when the ink tank is not mounted.

Therefore, according to the above-described configuration, the presence or absence of the ink tank can be detected without providing a special configuration for detecting the presence or absence of the ink tank. It is possible to detect the remaining amount and the presence or absence of the ink tank.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet type recording head which performs recording by forming a flying liquid by utilizing thermal energy among ink jet recording methods.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to the drive signal
This is effective because air bubbles in the interior can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

[0093] The configuration of the recording head may include a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body, or an electric connection with the apparatus main body or ink from the apparatus main body by being mounted on the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

Further, as for the type and number of the recording heads to be mounted, two or more recording heads may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0099]

As described above, according to the present invention, in a configuration of an ink jet recording apparatus using an ink tank having a built-in ink absorber for maintaining a stable ink supply performance, the ink remaining in the ink tank is reduced. It is possible to accurately detect a decrease in the amount. Further, in the configuration of the present invention, the amount of light received by the light receiving element is reduced to a predetermined value due to a change in the reflectance of the wall surface inside the ink tank caused by a difference in the refractive index between the ink tank and the ink, and scattering of light by the ink absorber. When it becomes larger, it utilizes the principle of detecting that the remaining amount of ink in the ink tank has dropped.Because there are many reflective elements at the time of detection, multiple ink tanks can be accurately detected by one detection system. Can be detected.

Further, the presence / absence of an ink tank can be detected with the same configuration.

[Brief description of the drawings]

FIG. 1 is a side view of a carriage according to an embodiment of the present invention.

FIG. 2 is a side view of a carriage showing a tank mounted state according to one embodiment of the present invention.

FIG. 3 is a schematic view of the carriage according to the embodiment of the present invention as viewed from the bottom side.

FIG. 4 is an overall schematic diagram of an apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an ink sensor used in one embodiment of the present invention.

FIG. 6 is a diagram illustrating the principle of detecting the remaining amount of ink according to the present invention.

FIG. 7 is a diagram illustrating the principle of detecting the remaining amount of ink according to the present invention.

FIG. 8 is a diagram illustrating an output of a photo interrupter according to one embodiment of the present invention.

FIG. 9 is a diagram illustrating a configuration of an ink sensor according to an embodiment of the present invention.

FIG. 10 is a diagram illustrating a display of a detection result of a remaining amount of ink according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating a configuration of a carriage and an ink sensor according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 6 Photo interrupter 7 Ink tank 7a Absorber 21 Print head

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hitoshi Nishikori 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-61-35962 (JP, A) JP-A-5 -332812 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/175

Claims (8)

(57) [Claims] 1. An ink cartridge containing inks of different colors.
A Nkutanku, comprising: a plurality of Lee <br/> Nkutanku with a built-in ink absorber, a nozzle for ejecting ink
A carriage on which an inkjet head can be mounted, and a front
Scanning means for scanning the carriage.
Ink of multiple colors supplied by the ink tank
In an ink jet recording apparatus which performs recording by discharging from nozzles of a jet head, a plurality of inks mounted on the carriage of an apparatus main body.
Provided at a position corresponding to the ink absorber of the tank,
Light is illuminated on the position of the ink absorber in the ink tank.
A light emitting element that emits light and a light receiving element that detects light.
And the sensor facing the position of the absorber in the ink tank.
Of the light emitted by the light emitting element in the
Based on the result of detecting the emitted light by the light receiving element,
Detecting means for detecting a decrease in the amount of ink remaining in the ink tank
And the scanning means scans the carriage to scan the carriage.
Multiple ink tanks mounted on the ridge
Sequentially moved to the opposing position, and a plurality of
Low ink level of each ink tank is detected
At the same time, the detecting means detects the difference in the refractive index between the ink tank and the ink.
Changes in the reflectivity of the wall surface inside the ink tank,
And the scattering of light by the ink absorber,
When the amount of light received by the optical element exceeds a predetermined value,
Detecting a low ink level in the ink tank
An ink jet recording apparatus comprising: 2. The apparatus according to claim 1 , wherein said sensor is mounted on said carriage.
Is provided so that light can be irradiated from the bottom of the ink tank
The ink jet recording apparatus according to claim 1, wherein: 3. The sensor according to claim 1, wherein the sensor irradiates and receives light at a plurality of positions of the ink tank absorber of the ink tank.
A plurality is provided so that the amount of light can be detected.
The ink jet recording apparatus according to claim 1, wherein 4. A moving means for moving said sensor.
Moving the sensor by the moving means.
With this method, light irradiation and light reception amount detection are performed at a plurality of positions of the ink absorber in the ink tank.
2. The ink jet recording apparatus according to claim 1, wherein: 5. The ink jet recording apparatus according to claim 1, characterized in that the table <br/> shown in accordance with the detection result of the detecting means. Ru is mounted on the carriage together and wherein said ink tank and said ink jet head
The ink jet recording apparatus according to claim 1, wherein: 7. The ink tank according to claim 7, wherein the ink tank includes the ink absorber.
Non-pressure generating part that accommodates ink and ink
And the ink storage section
The ink jet according to any one of claims 1 to 6, wherein
Unit recording device. 8. The sensor further detects whether or not an ink tank is mounted on the carriage.
An ink jet recording apparatus according to claim 1, characterized in Ukoto.