JP2000185411A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply ink only for a time corresponding to the quantity of ink ejection and to shorten the detection time of the residual quantity of ink by arranging means for detecting the quantity of ink being ejected from a recording head, and means for supplying ink corresponding to the detected quantity from a first ink tank to a second ink tank. SOLUTION: When ink is supplied from an ink cartridge 300 to a subtank 301, all valves 304, 305, 306 are closed to establish an enclosed inner space interconnecting the ink cartridge 300 to the subtank 301. Subsequently, a pressure pump (tube pump) 302 is turned in the direction of arrow A and the tube thereof is pressed to supply ink from the direction of arrow B. When the quantity of ink in the subtank 301 exceeds a specified level, ink in the subtank 301 returns back to the ink cartridge 300 from the direction of arrow C. The printer is provided with an ink channel along with an ink supply system and an ink channel L1 for supplying ink in the subtank 301 to a recording head is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a first and a second ink tank such as a sub-tank unit and an ink cartridge for ejecting minute ink droplets toward a recording medium such as paper. The present invention relates to an ink jet recording apparatus for recording characters and images.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus provided with a sub-tank for storing ink for supplying ink to a recording head and a replaceable ink cartridge for accommodating the ink to be supplied to the sub-tank is provided in the sub-tank. The provided ink level sensor is monitored at any time. Then, when the sensor is in a non-contact state with the ink surface, it is determined that the remaining amount of ink in the sub tank is small, and the ink cartridge is supplied to the sub tank for a maximum time (the ink is filled in the sub tank). (The maximum time required for the ink supply). Further, the detection of the presence or absence of ink in the ink cartridge is performed by a change in an ink level sensor in the sub tank after the ink is supplied from the ink cartridge to the sub tank.
I was judging.

[0003]

However, such a conventional method of detecting the presence or absence of the remaining amount of ink involves a case where "no ink" is detected during printing and the printing operation is interrupted to supply ink. was there. Further, the detection of the remaining amount of ink in the sub tank can be determined only at one point which is a state change point of the ink level sensor. Furthermore, in order to detect the presence or absence of the ink in the ink cartridge, there is a problem that the ink must be supplied to the sub tank every time for a maximum time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional example. An object of the present invention is to grasp the amount of ink ejected from a recording head and supply ink for a time corresponding to the amount of ink ejected. An object of the present invention is to shorten the time required for detecting the presence or absence of a remaining amount and for supplying ink, and to stabilize the performance of a printing apparatus.

[0005]

An ink jet recording apparatus of the present invention records an image on a recording medium using a recording head capable of discharging ink supplied from a first ink tank to a second ink tank. In the ink jet recording apparatus, a discharge amount detecting means for detecting a discharge amount of the ink from the recording head, and an ink corresponding to the discharge amount of the ink detected by the discharge amount detecting means is supplied from the first ink tank to the second ink tank. And an ink supply means for supplying the ink to the ink tank.

According to the present invention, for example, when the number of ink droplets ejected from a recording head exceeds a predetermined specified value,
Ink can be supplied by an amount corresponding to the ink ejection amount calculated based on the number of ejected ink droplets.
In addition, by using a sensor for detecting the amount of ink in the ink tank, the ink supply can be terminated when the sensor detects the full state of the ink during ink supply.

Further, as a result of the ink supply, if the sensor does not detect the full state of the ink, the absence of the ink in the first ink tank such as the ink cartridge can be detected. If a sensor in the ink tank detects an empty state of the ink, it can be determined that the recording is impossible.

Further, by setting the execution timing of the ink supply as described above after the end of the printing, it is possible to avoid the interruption due to the absence of the ink during the printing.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a perspective view of a color printer system used in this embodiment. FIG.
1, a color card printer 100 as an ink jet recording apparatus is connected to an external processing device 102 such as a host computer by a cable 101. The printer 100 is connected to the external processing device 10 via a cable 101.
When the image information and the data are transferred from the printer 2, recording is performed on a card sheet as a recording medium built in the feeder unit 103, and the recorded card sheet is stored in the stacker unit 104. I have.

FIG. 2 shows the label color printer 10 of FIG.
0 is a schematic sectional view of FIG. In FIG. 2, the color card printer 100 incorporates a total of six ink jet line recording heads as recording elements in accordance with the type of ink. 201 is for black ink ejection, 202 is for cyan ink ejection, 203 is for cyan light ink ejection, 2
Reference numeral 04 denotes a line recording head for discharging magenta ink, 205 denotes a line recording head for discharging magenta light ink, and 206 denotes a line recording head for discharging yellow ink. Each recording head 201, 202, 20
3, 204, 205, and 206 correspond to the ink cartridges 207, 208, 209, 210, and 21, respectively.
Ink is supplied from the recording medium S1, 212 to eject the ink of each color, so that the card paper S as a recording medium
To record.

FIG. 3 shows the color card printer 10 of FIG.
FIG. 4 is an explanatory diagram of an ink supply system of No. 0; In FIG. 3, one of the print heads 201 to 206 is represented as a print head 307, and the ink cartridges 207 to 212
The ink cartridge 300 is representative of one of them. Here, the term “ink supply” refers to supplying ink from the ink cartridge 300 to the sub tank 301.

In FIG. 3, an ink cartridge 300
When the ink is supplied to the sub-tank 301 from the sub-tank 301, the valves 304, 305, and 306 are all closed to make the interior of the ink cartridge 300 and the inside of the sub-tank 301 a closed space communicating with each other. Then, the pressurizing pump (tube pump) 302 is rotated in the direction of arrow A, and the tube is pressed to supply ink from the direction of arrow B. When the amount of ink in the sub tank 301 exceeds a certain amount, the ink in the sub tank 301 returns to the ink cartridge 300 from the direction of arrow C.

The printer 100 is provided with an ink supply system for supplying ink from the ink cartridge 300 to the sub-tank 301 and various ink flow paths as shown in FIG. In FIG. 3, L1 is an ink flow path for supplying the ink in the sub tank 301 to the recording head 307. A cap 307A receives ink discharged from the recording head 307 to recover the ink ejection state, that is, ink that does not contribute to image recording. L2 transfers the ink in the cap 307 to the sub tank 3 using the recycle pump 303.
This is an ink collection path to be collected in the area 01. Also, 308
Denotes an ink level sensor provided in the sub tank 301, and 309 denotes an air buffer tank.

FIG. 4 shows the color card printer 10 of FIG.
It is a block diagram of a control system of No. 0.

In FIG. 4, image data is transferred to a printer 100 from an external processing device 102 such as a host computer. Then, in order to reproduce the designated color with each ink color, an image memory 41 for yellow ink is used.
2. Image memory 413 for magenta ink, image memory 414 for cyan ink, image memory 415 for black ink, image memory 416 for magenta light ink, image memory 41 for cyan light ink
7, a print image is drawn.

After the image development for the six colors of ink is completed, the main controller 400 drives the drive motor 405 for conveying the card paper S as a recording medium via the motor driver 403. Then, in synchronization with the conveyance of the card paper S, the driver controller 40
6 is an image memory 412, 413, 414, 41
5, 416, 417, the recording data is sequentially read out,
The print data is transferred to the print heads 201, 202, 203, 204, 205, 2 via a head drive circuit 420.
06. The recording heads 201 to 206 discharge ink from respective ink discharge ports in response to a drive signal corresponding to image data. The ejection ink droplet number calculation circuit 420A counts the number of ink droplets ejected from each of the recording heads 201 to 206. The number of ink droplets can be counted based on a drive signal corresponding to image data.

In FIG. 4, reference numeral 404 denotes a motor for driving the pumps 302 and 303 shown in FIG. 3, and reference numeral 402 denotes a driver thereof. Also, 401
Is a memory having a ROM for storing various programs, a RAM used as a work area, and the like.

FIG. 5 is an enlarged view of the ink level sensor 308 provided in the sub tank 301. In FIG. 5, reference numeral 600 denotes an empty sensor for detecting that the remaining amount of ink in the sub tank 301 is exhausted, and reference numeral 601 denotes an ink full sensor for detecting that the ink in the sub tank 301 is full. In the case of this example, the sky sensor 600 is G
By providing an electrode facing the ND electrode 602,
It constitutes a part of the ink level sensor 308, and when the ink in the sub tank 301 runs out, the ink does not intervene between the electrodes and becomes non-conductive.
In addition, the full tank sensor 601 includes an electrode facing the GND electrode 602, so that the ink level sensor 3
08, and when the sub tank 301 is filled with ink, the ink is interposed between the electrodes to be in a conductive state (ON).

FIG. 6 is a flowchart of an ink supply sequence according to this embodiment. Hereinafter, the ink supply sequence will be described with reference to FIG.

First, it is determined whether or not the total number of ink droplets ejected for each recording head calculated by the ejected ink droplet number calculation circuit 420A is equal to or greater than a specified value (step S700). If it is less than the specified value, no ink is supplied and unnecessary ink is not supplied. On the other hand, when the cumulative number of ejected ink droplets is equal to or more than the specified value, the amount of ink consumption corresponding to the cumulative number of ejected ink droplets is obtained, and then the ink supply time (T) according to the amount of ink consumption is calculated ( Step S701). Specifically, the ink supply time (T) is calculated by the following equation (1).

T = C × ΔV / F (1) where C is the cumulative number of ejected ink droplets, ΔV is the ejection amount per ejected ink, and F is the unit time of the ink supply system. Per unit ink supply amount (ink pumping amount per unit time of the pump 302). (C × ΔV) is the ink consumption corresponding to the cumulative number of ink droplets C to be ejected. The ink supply time T corresponds to the ink supply start described later (step S7).
02) to the time required to determine that there is no ink in the ink cartridge 300 (step S706).

Thereafter, ink supply is started (step S).
702), and waits for the ink full sensor 601 to be turned ON (full tank detection) or a timeout of the ink supply time T (steps S703 and S704). Ink supply time T
Is counted down from the time point when the ink supply is started in step S702.

If the ink full sensor 601 is turned on before the ink supply time T times out,
The ink supply is continued for a fixed time (step S70)
4, S705). The certain time period is an ink supply time from when the ink full sensor 601 is turned ON to when the sub tank 301 is fully filled with ink. In this way, the ink supply is stopped after the inside of the sub tank 301 is actually full (step S707). Also, as described above, the sub tank 301
When the inside is full, the count value of the cumulative number of ink droplets is cleared.

On the other hand, if the ink supply time T has expired before the ink full sensor 601 is turned on, it is determined that there is no ink remaining in the ink cartridge 300 (steps S704 and S706). The ink supply is stopped (step S707).

As described above, according to the present embodiment, it is possible to prevent unnecessary supply of ink and to reduce the time required for detecting the absence of ink in the ink cartridge 300. Further, the amount of ink in the sub-tank 301 can be always grasped, and it is possible to prevent the ink in the sub-tank 301 from running out during printing.

For example, if the ink cannot be supplied until the inside of the sub-tank 301 becomes full due to the shortage of the remaining amount of ink in the ink cartridge 300, the time required for the ink supply at that time is taken into consideration. 301
The ink amount in the sub-tank 301 is always accurately grasped by calculating the ink amount of the shortage that could not be filled to the full state and setting the ink amount of the shortage as the current accumulated number of ink droplets. Can be.

(Second Embodiment) FIGS. 7 to 10 are views for explaining a second embodiment of the present invention. This example is an application example as a color card printer 100 similar to the first embodiment described above.

FIG. 7 is a block diagram of a control system of the printer 100 according to the present embodiment. The same parts as those in FIG. 4 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. . In the case of this example, a head temperature detection circuit 521 for detecting the temperature of each of the recording heads 201 to 205 is provided. Based on the relationship between the print head temperature and the amount of ink ejected per ink drop as shown in FIG. 9, the main controller 400 determines the amount of ink per ejected ink in accordance with the detected temperature of the print head by the detection circuit 521. After correcting the ejection amount, the ink supply time (T) will be described later.
Is calculated. Also, as shown in FIG. 10, the head temperature rises as the number of printed sheets increases continuously. A curve 1000 in FIG. 10 shows a temperature change when the print duty is relatively high, and a curve 1001 shows a temperature change when the print duty is relatively low. FIG.
The ambient temperature was 25 ° C.

FIG. 8 is a flowchart of an ink supply sequence according to this embodiment. In the case of this example, steps S700 ′ and S700 ′ are different from FIG. 6 of the first embodiment.
Only S701 'is different.

First, in step S700 ', it is determined whether or not the consumed ink amount is equal to or greater than a specified value. The consumed ink amount is calculated from the number of ejected ink droplets calculated by the ejected ink droplet number calculation circuit 420A from the amount of ejected ink per ejected ink droplet corresponding to the detected temperature of the head. If it is less than the specified value, no ink is supplied and unnecessary ink is not supplied. On the other hand, when the consumed ink amount is equal to or more than the specified value,
The ink supply time (T ') according to the consumed amount is calculated (step S701'). Specifically, the ink supply time (T ') is calculated by the following equation (2).

T ′ = C ′ × ΔV ′ / F (2) where C ′ is the number of ejected ink droplets, ΔV ′ is the ejection amount per ejected ink that varies depending on the head temperature, and F Is
This is the amount of ink supply per unit time of the ink supply system (the amount of ink pumped by the pump 302 per unit time). (C ′ × ΔV ′) is the consumed ink amount corrected in accordance with the head temperature. With respect to the ink droplets ejected up to the time of this calculation, the ejection amount per ink droplet is corrected in accordance with the head temperature. Means the consumed ink amount calculated after the calculation. For example, the number of ink droplets ejected at predetermined intervals of the head temperature is counted, and the amount of ink consumed at predetermined intervals of the head temperature is determined from the count value and the ejection amount per ink droplet corresponding to the head temperature. By accumulating them, the amount of consumed ink as (C ′ × ΔV ′) can be obtained.

As described above, in the case of the present embodiment, a more accurate amount of consumed ink can be obtained and taken into account by taking into account the change in the ejection amount per ink droplet due to the head temperature.

(Other Embodiments) In one recording head, two or more kinds of ejection amounts per ink drop may be changed. Thus, even in the case of a high-resolution printer having a plurality of types of ink ejection amounts,
By counting the number of ejected ink droplets for each ejection amount, the consumed ink ejection amount is calculated, and the same operation and effect as in the above-described embodiment can be obtained.

Further, the discharge amount of ink which does not contribute to recording of an image discharged to recover the ink discharge state of the recording head may be added to the consumed ink discharge amount.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

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 the recorded information and giving a rapid temperature rise exceeding the 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 this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. 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 liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As this pulse-shaped drive signal, those described in U.S. 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.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
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, and an aperture for absorbing a pressure wave of thermal energy is provided. 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 attached to 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.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. 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, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet system generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent the temperature rise due to thermal energy by using the energy of the state change from the solid state of the ink to the liquid state, or to prevent the ink from evaporating, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

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.

[0045]

As described above, according to the present invention,
By supplying ink by the amount of ink consumed, the time required for ink supply can be reduced, the time required for detecting the absence of ink in the ink cartridge can be reduced, and stable performance can be achieved without causing recording interruption due to ink absence. .

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the ink jet recording apparatus of FIG.

FIG. 3 is a piping diagram of an ink supply system of the inkjet recording apparatus of FIG.

FIG. 4 is a block diagram of a control system of the ink jet recording apparatus of FIG.

FIG. 5 is an enlarged view for explaining the inside of a sub tank in FIG. 3;

FIG. 6 is a flowchart of an ink supply sequence according to the first embodiment of the present invention.

FIG. 7 is a block diagram of a control system of an inkjet recording apparatus according to a second embodiment of the present invention.

FIG. 8 is a flowchart of an ink supply sequence according to the second embodiment of the present invention.

FIG. 9 is a correlation diagram between the temperature of the inkjet recording head and the amount of ejected ink droplets.

FIG. 10 is a correlation diagram between the number of prints and a temperature change of an ink jet recording head.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 color card printer (inkjet recording device) 101 printer-connection cable 102 host computer 103 feeder unit 104 stacker unit 201, 202, 203, 204, 205, 206 recording head 207, 208, 209, 210, 211, 212 ink cartridge 300 Ink cartridge (first ink tank) 301 Sub tank (second ink tank) 302 Pressure pump 303 Recycle pump 304, 305, 306 Valve 307 Recording head 308 Ink level sensor 400 Main controller 401 Memory 402 Motor driver 403 Motor driver 404 Motor 405 Feed motor 406 Driver controller 412, 413, 414, 415 Image memory 20 head drive circuit 420A ejected ink droplet number calculating circuit

Claims (10)

[Claims] An ink jet recording apparatus for recording an image on a recording medium by using a recording head capable of discharging ink supplied from a first ink tank to a second ink tank; An ejection amount detection unit that detects an ejection amount; and an ink supply unit that supplies ink corresponding to the ejection amount of the ink detected by the ejection amount detection unit from the first ink tank to the second ink tank. An ink jet recording apparatus characterized in that: 2. The ink supply means according to claim 1, wherein said ink supply means supplies said ink from said first ink tank to said second ink tank when a discharge amount of said ink detected by said discharge amount detection means becomes a predetermined amount or more. The ink jet recording apparatus according to claim 1, wherein the ink is supplied. 3. The method according to claim 2, wherein the ejection amount detection unit detects an ink ejection amount based on the number of ink droplets ejected from the recording head and an ink ejection amount per ink droplet. The ink jet recording apparatus according to claim 1 or 2, wherein 4. An ink jet recording apparatus according to claim 3, wherein said discharge amount detecting means corrects an ink discharge amount per one of said ink droplets according to a temperature of said recording head. 5. The ejection amount detection unit according to claim 1, wherein the ejection amount detection unit detects an ejection amount of the ink including an amount of ink ejected from the recording head to recover an ejection state. 3. The ink jet recording apparatus according to claim 1. 6. The method according to claim 1, wherein the ink supply unit is configured to supply the second ink from the first ink tank for an ink supply time corresponding to the ink discharge amount detected by the discharge amount detection unit.
The ink jet recording apparatus according to claim 1, wherein the ink is supplied to the ink tank. 7. The ink supply device according to claim 7, further comprising: a sensor for detecting that the second tank is filled with ink, wherein the sensor detects that the ink is full during ink supply by the ink supply means. 7. The ink jet recording apparatus according to claim 1, wherein the supply is terminated. 8. The ink supply device according to claim 1, further comprising a sensor configured to detect that the second tank is filled with ink, wherein the ink supply unit includes an ink corresponding to the ink discharge amount detected by the discharge amount detection unit. Ink is supplied from the first ink tank to the second ink tank for a supply time, and when the sensor does not detect ink fullness within the ink supply time, the remaining ink in the first ink tank is supplied. 8. The ink jet recording apparatus according to claim 1, wherein the ink supply unit is stopped when it is determined that there is no amount. 9. The ink jet recording apparatus according to claim 1, wherein the first ink tank is a replaceable ink cartridge. 10. The ink jet recording apparatus according to claim 1, wherein the recording head has an electrothermal transducer that generates thermal energy used for discharging ink.