JP3611976B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes first and second ink tanks such as a sub tank unit and an ink cartridge, and records characters and images by ejecting minute ink droplets toward a recording medium such as paper. The present invention relates to an inkjet recording apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an ink jet recording apparatus provided with a sub tank that stores ink for supplying ink to a recording head and a replaceable ink cartridge that stores ink to be supplied to the sub tank includes an ink level sensor provided in the sub tank. I am monitoring from time to time. When the sensor is in a non-contact state with respect to the ink surface, it is determined that the remaining amount of ink in the sub tank is small, and the maximum time (from the ink tank to the sub tank is filled with ink) is determined from the ink cartridge to the sub tank. Ink supply for the maximum time required). Further, the detection of the presence or absence of ink in the ink cartridge is determined by the change in the ink level sensor in the sub tank after the ink supply operation from the ink cartridge to the sub tank.
[0003]
[Problems to be solved by the invention]
However, in such a conventional method for detecting the presence or absence of the remaining amount of ink, “no ink” is detected during recording, and the recording operation may be interrupted to supply ink. In addition, detection of the remaining amount of ink in the sub tank can be determined only at one point, which is the state change point of the ink level sensor. Furthermore, in order to detect the presence / absence of ink in the ink cartridge, there is a problem that the ink must be supplied to the sub tank for the maximum time each time.
[0004]
The present invention has been made in view of the above-described conventional example, and an object of the present invention is to grasp the amount of ink discharged from the recording head, and to supply ink for a time corresponding to the amount of discharge, thereby reducing the amount of ink remaining. It is to reduce the time required for the presence / absence detection and ink supply and to stabilize the performance of the recording apparatus.
[0005]
[Means for Solving the Problems]
The inkjet recording apparatus of the present invention is an inkjet recording apparatus that 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. Discharge amount detection means for detecting the ink discharge amount, and ink supply means for supplying ink corresponding to the ink discharge amount detected by the discharge amount detection means from the first ink tank to the second ink tank And a sensor for detecting that the second tank is filled with ink, and the ink supply means supplies ink corresponding to the ink discharge amount detected by the discharge amount detection means. Ink is supplied from the first ink tank to the second ink tank only for a period of time, and the sensor is turned on within the ink supply time. When the not detected filling, characterized in that stopping the ink supply means determines that there is no ink remaining amount of the first ink tank.
[0006]
According to the present invention, for example, when the number of ink droplets ejected from the recording head exceeds a predetermined specified value, ink is supplied by an amount corresponding to the ink ejection amount calculated based on the number of ejected ink droplets. Can be performed. Also, by using a sensor that detects the amount of ink in the ink tank, the ink supply can be terminated when the sensor detects a full ink state during the ink supply.
[0007]
Furthermore, as a result of ink supply, if the sensor does not detect a full ink state, it is possible to detect the absence of ink in the first ink tank such as an ink cartridge. Further, if the sensor in the ink tank detects the ink empty state, it can be determined that the recording is impossible.
[0008]
Further, by setting the ink supply execution timing as described above after the end of recording, it is possible to avoid interruption due to the absence of ink during recording.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
(First embodiment)
FIG. 1 is a perspective view of a color printer system used in this embodiment. In FIG. 1, a color card printer 100 as an ink jet recording apparatus is connected to an external processing apparatus 102 such as a host computer via a cable 101. The printer 100 performs recording on a card sheet as a recording medium built in the feeder unit 103 by transferring image information and data from the external processing apparatus 102 via the cable 101, and the recording is performed. The card paper is stored in the stacker unit 104.
[0011]
FIG. 2 is a schematic sectional view of the label color printer 100 of FIG. In FIG. 2, the color card printer 100 has a total of six ink-jet line recording heads as recording elements corresponding to the type of ink. Reference numeral 201 denotes a black ink discharge, 202 a cyan ink discharge, 203 a cyan light ink discharge, 204 a magenta ink discharge, 205 a magenta light ink discharge, and 206 a yellow ink discharge line recording head. Each of the recording heads 201, 202, 203, 204, 205, 206 is supplied with ink from the corresponding ink cartridges 207, 208, 209, 210, 211, 212, and discharges the ink of each color. Then, recording is performed on the card paper S as a recording medium.
[0012]
FIG. 3 is an explanatory diagram of an ink supply system of the color card printer 100 of FIG. In FIG. 3, one of the recording heads 201 to 206 is represented as a recording head 307, and one of the ink cartridges 207 to 212 is represented as an ink cartridge 300. Here, the ink supply means supplying ink from the ink cartridge 300 to the sub tank 301.
[0013]
In FIG. 3, when ink is supplied from the ink cartridge 300 to the sub tank 301, all the valves 304, 305, and 306 are closed so that the inside of the ink cartridge 300 and the sub tank 301 communicates with each other. Then, the pressure 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.
[0014]
In addition to the ink supply system for supplying ink from the ink cartridge 300 to the sub tank 301, the printer 100 includes various ink flow paths as shown in FIG. In FIG. 3, L <b> 1 is an ink flow path for supplying the ink in the sub tank 301 to the recording head 307. Reference numeral 307A denotes a cap that receives ink discharged from the recording head 307 to recover the ink ejection state, that is, ink that does not contribute to image recording. L <b> 2 is an ink collection path for collecting the ink in the cap 307 into the sub tank 301 using the recycle pump 303. Reference numeral 308 denotes an ink level sensor provided in the sub tank 301, and reference numeral 309 denotes an air buffer tank.
[0015]
FIG. 4 is a block diagram of a control system of the color card printer 100 of FIG.
[0016]
In FIG. 4, image data is transferred from an external processing apparatus 102 such as a host computer to the printer 100. In order to reproduce the designated color by each ink color, an image memory 412 for yellow ink, an image memory 413 for magenta ink, an image memory 414 for cyan ink, an image memory 415 for black ink, and a magenta light ink Print images are drawn in the image memory 416 and the image memory 417 for cyan light ink.
[0017]
As described above, after the image development for the six ink colors 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. In synchronization with the conveyance of the card paper S, the driver controller 406 sequentially reads out the recording data from the image memories 412, 413, 414, 415, 416, and 417 and passes the recording data through the head driving circuit 420. And transferred to the recording heads 201, 202, 203, 204, 205, 206. The recording heads 201 to 206 discharge ink from the respective ink discharge ports by a drive signal corresponding to the 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.
[0018]
In FIG. 4, 404 is a motor for driving the pumps 302, 303, etc. in FIG. 3, and 402 is the driver. Reference numeral 401 denotes a memory having a ROM for storing various programs, a RAM used as a work area, and the like.
[0019]
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 that detects that the remaining amount of ink in the sub tank 301 is exhausted, and reference numeral 601 denotes an ink full sensor that detects that the sub tank 301 is full of ink. In the case of this example, the empty sensor 600 is provided with an electrode facing the GND electrode 602 to constitute a part of the ink level sensor 308. When the ink in the sub tank 301 runs out, the gap between these electrodes Ink does not intervene in this state, and it becomes a non-conductive state. In addition, the full tank sensor 601 forms a part of the ink level sensor 308 by providing an electrode facing the GND electrode 602. When the sub tank 301 is filled with ink, the ink is interposed between the electrodes. It becomes conductive (ON) by intervening.
[0020]
FIG. 6 is a flowchart of an ink supply sequence in the present embodiment. Hereinafter, the ink supply sequence will be described with reference to FIG.
[0021]
First, it is determined whether or not the total number of ejected ink droplets for each recording head calculated by the ejected ink droplet number calculating circuit 420A is equal to or greater than a specified value (step S700). If it is less than the specified value, unnecessary ink supply is eliminated without supplying ink. On the other hand, when the cumulative number of ejected ink drops is equal to or greater than the specified value, the ink consumption corresponding to the cumulative number of ejected ink drops is obtained, and the ink supply time (T) corresponding to the ink consumption is calculated ( Step S701). Specifically, the ink supply time (T) is calculated by the following equation (1).
[0022]
T = C × ΔV / F (1)
Here, C is the cumulative number of ejected ink droplets, ΔV is the ejected amount per ejected ink, and F is the ink supply amount per unit time of the ink supply system (ink pumping amount per unit time of the pump 302). is there. Further, (C × ΔV) is an ink consumption amount corresponding to the cumulative number C of ejected ink droplets. The ink supply time T corresponds to the time required from the start of ink supply described later (step S702) until it is determined that there is no ink in the ink cartridge 300 (step S706).
[0023]
Thereafter, ink supply is started (step S702), and the ink full sensor 601 is turned on (full tank detection) or the ink supply time T is timed out (steps S703 and S704). The ink supply time T is counted down from the ink supply start time in step S702.
[0024]
If the ink full sensor 601 is turned on before the ink supply time T times out, the ink supply is continued for a predetermined time (steps S704 and S705). The fixed time is an ink supply time until the sub tank 301 is actually filled with ink after the ink full sensor 601 is turned ON. In this way, the ink supply is stopped after the inside of the sub tank 301 is actually full (step S707). In addition, when the sub tank 301 is filled up in this way, the count value of the cumulative number of ink ejected droplets is cleared.
[0025]
On the other hand, if the ink supply time T is up before the ink full sensor 601 is turned ON, it is determined that there is no remaining ink in the ink cartridge 300 (steps S704 and S706), and then the ink supply is performed. Stop (step S707).
[0026]
As described above, according to this embodiment, it is possible to prevent unnecessary ink supply from being performed, and it is possible to reduce the time required to detect the absence of ink in the ink cartridge 300. In addition, 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 recording.
[0027]
For example, if ink cannot be supplied until the sub-tank 301 is filled up due to a shortage of ink remaining in the ink cartridge 300, the sub-tank 301 is checked from the time required for ink supply at that time. The ink amount in the sub tank 301 can always be accurately grasped by obtaining the ink amount of the shortage that could not be filled and setting the ink amount of the shortage as the current cumulative number of ink ejection droplets. .
[0028]
(Second Embodiment)
7 to 10 are diagrams for explaining a second embodiment of the present invention. This example is an application example as the color card printer 100 similar to the first embodiment described above.
[0029]
FIG. 7 is a block diagram of the control system of the printer 100 of this example. The same reference numerals are given to the same portions as those in FIG. 4 of the first embodiment described above, 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. From the relationship between the temperature of the recording head and the ejection amount per ink droplet ejection ink as shown in FIG. 9, the main controller 400 determines the per-ejection ink droplet according to the detection temperature of the recording head by the detection circuit 521. The ink supply time (T) is calculated as will be described later by correcting the ejection amount. Further, as shown in FIG. 10, the head temperature rises with a continuous increase in the number of printed sheets. A curve 1000 in FIG. 10 shows a temperature change when the printing duty is relatively high, and a curve 1001 shows a temperature change when the printing duty is relatively low. In FIG. 10, the ambient temperature was set to 25 ° C.
[0030]
FIG. 8 is a flowchart of an ink supply sequence in the present embodiment. In this example, only steps S700 ′ and S701 ′ are different from FIG. 6 of the first embodiment described above.
[0031]
First, in step S700 ′, it is determined whether the consumed ink amount is equal to or greater than a specified value. The consumed ink amount is calculated from the ejected ink droplet number calculated by the ejected ink droplet number calculating circuit 420A from the ejected amount per ejected ink corresponding to the detected temperature of the head. If it is less than the specified value, unnecessary ink supply is eliminated without supplying ink. On the other hand, when the consumed ink amount is equal to or greater than the specified value, the ink supply time (T ′) corresponding to the consumed amount is calculated (step S701 ′). Specifically, the ink supply time (T ′) is calculated by the following equation (2).
[0032]
T ′ = C ′ × ΔV ′ / F (2)
Here, C ′ is the number of ejected ink droplets, ΔV ′ is the ejected amount per ejected ink depending on the head temperature, and F is the ink supply amount per unit time of the ink supply system (per unit time of the pump 302). Ink pressure feed amount). In addition, (C ′ × ΔV ′) is the ink consumption corrected according to the head temperature. Regarding the ink droplets ejected up to this calculation time, the ejection amount per ink droplet is corrected according to the head temperature. This means the amount of ink consumed calculated after For example, the number of ejected ink droplets at a predetermined interval of the head temperature is counted, and the amount of ink consumed at the predetermined interval of the head temperature is obtained from the counted value and the ejection amount per ink droplet corresponding to the head temperature. By accumulating it, the consumed ink amount as (C ′ × ΔV ′) can be obtained.
[0033]
As described above, in the case of the present embodiment, it is possible to obtain and cope with a more accurate consumed ink amount by taking into account the change in the ejection amount per drop of ink caused by the head temperature.
[0034]
(Other embodiments)
In one recording head, two or more types 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, the consumed ink ejection amount is calculated by counting the number of ejected ink droplets for each ejection amount, and the embodiment described above. Similar effects can be obtained.
[0035]
In addition, an ink discharge amount that 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.
[0036]
(Other)
The present invention includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for ejecting ink, particularly in the ink jet recording system, and the ink is generated by the thermal energy. In the recording head and the recording apparatus of the type that causes the state change, excellent effects are brought about. This is because such a system can achieve high recording density and high definition.
[0037]
As for the typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid and, as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0038]
As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting part The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the lens is disposed in the bending region, are also included in the present invention. In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. The effect of the present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461 which discloses a configuration corresponding to the discharge unit. That is, whatever the form of the recording head is, according to the present invention, recording can be performed reliably and efficiently.
[0039]
Furthermore, 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 that can be recorded by the recording apparatus. As such a recording head, either a configuration satisfying the length by a combination of a plurality of recording heads or a configuration as a single recording head formed integrally may be used.
[0040]
In addition, even the serial type as shown in the above example can be connected to the main body of the recording head or attached to the main body of the device so that electrical connection with the main body of the device and ink supply from the main body are possible. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.
[0041]
In addition, it is preferable to add a recording head ejection recovery means, a 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. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.
[0042]
Also, regarding the type or number of recording heads to be mounted, for example, a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities, in addition to one provided corresponding to a single color ink. May be used. That is, for example, as a recording mode of the recording apparatus, not only a recording mode of only a mainstream color such as black, but also a recording head may be configured integrally or by a combination of a plurality of different colors, Alternatively, the present invention is extremely effective for an apparatus having at least one of full-color recording modes by color mixing.
[0043]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. In the ink jet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that it is in the stable discharge range. A liquid material may be used. In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying thermal energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0044]
In addition, the ink jet recording apparatus according to the present invention may be used as an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. The thing etc. may be sufficient.
[0045]
【The invention's effect】
As described above, according to the present invention, by supplying ink as much as the amount of ink consumed, the time required for ink supply is shortened, the time required for detecting the absence of ink in the ink cartridge, and the absence of ink. Stable performance can be obtained without interrupting recording.
[Brief description of the drawings]
FIG. 1 is a perspective view of an ink jet recording apparatus as a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the ink jet recording apparatus of FIG.
3 is a piping diagram of an ink supply system of the ink jet recording apparatus of FIG. 1. FIG.
4 is a block diagram of a control system of the ink jet recording apparatus of FIG. 1. FIG.
FIG. 5 is an enlarged view for explaining the inside of the 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 ink jet recording apparatus as 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 ink jet recording head and the amount of ejected ink droplets.
FIG. 10 is a correlation diagram between the number of printed sheets and the temperature change of the inkjet recording head.
[Explanation of symbols]
100 Color card printer (inkjet recording device)
101 Printer-connecting 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 420 Head Drive circuit 420A discharge ink droplet number calculation circuit

Claims (9)

In an ink jet recording apparatus that 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,
A discharge amount detecting means for detecting a discharge amount of ink from the recording head;
Ink supply means for supplying ink corresponding to the ink discharge amount detected by the discharge amount detection means from the first ink tank to the second ink tank ;
A sensor for detecting that the second tank is filled with ink;
With
The ink supply means supplies ink from the first ink tank to the second ink tank for an ink supply time corresponding to the ink discharge amount detected by the discharge amount detection means;
The ink supply means is stopped when it is determined that there is no remaining ink in the first ink tank when the sensor does not detect ink full within the ink supply time. Recording device. The ink supply means supplies ink from the first ink tank to the second ink tank when the ink discharge amount detected by the discharge amount detection means exceeds a predetermined amount. The inkjet recording apparatus according to claim 1. The discharge amount detection unit detects the discharge amount of ink based on the number of ink droplets discharged from the recording head and the ink discharge amount per one droplet of the ink droplets. Or the inkjet recording apparatus according to 2; The inkjet recording apparatus according to claim 3, wherein the ejection amount detection unit corrects an ink ejection amount per droplet of the ink droplet according to a temperature of the recording head. 5. The ink jet recording according to claim 1, wherein the discharge amount detection unit detects an ink discharge amount including an ink amount discharged for recovery of an ejection state from the recording head. apparatus. The ink supply means supplies ink from the first ink tank to the second ink tank for an ink supply time corresponding to the ink discharge amount detected by the discharge amount detection means. The ink jet recording apparatus according to claim 1. The second tank is provided with a sensor for detecting that the ink is filled therein,
7. The ink jet recording apparatus according to claim 1, wherein the ink supply is terminated when the sensor detects ink filling during ink supply by the ink supply unit. 8. The inkjet recording apparatus according to claim 1, wherein the first ink tank is a replaceable ink cartridge. 9. The ink jet recording apparatus according to claim 1 , wherein the recording head includes an electrothermal converter that generates thermal energy used for ejecting ink.

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