JP3484858B2 - 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 jet recording apparatus which has a recording head and ejects ink droplets onto recording paper in conformity with print data to form an image.

[0002]

2. Description of the Related Art An ink jet recording apparatus supplies ink stored in an ink container such as a cartridge or a tank to a recording head through a flow path and pressurizes the ink in a pressure generating chamber to eject the ink from a nozzle opening. It is configured to be ejected as droplets onto the recording paper.

As the solvent that constitutes the ink, a liquid having a high evaporation power is preferably used in order to reduce the bleeding on the recording paper as much as possible. Therefore, the ink solvent is a polymer that constitutes the ink container. Evaporate through a layer of material. Therefore, the ink container is stored in a packaging bag that has a metal layer formed on a polymer film and has an excellent gas barrier property in an unused state, and the viscosity of the internal ink increases (thickening) even after long-term storage. Measures are taken to prevent people from coming.

However, once the ink container is mounted on the ink jet recording apparatus, the solvent of the ink continues to evaporate from the ink container, which is a polymer material, from the start of mounting. Such evaporation of the ink solvent increases the viscosity of the ink as shown in FIG. 6, and due to this thickening of the ink, the ink amount of the ink droplet ejected as shown in FIG. And the print quality deteriorates.

In order to solve such a problem, JP-A-7-
As shown in Japanese Patent No. 232438, a memory for storing data for identifying the date and time of manufacture of the ink container and the date and time of attachment to the recording device is individually attached to each ink container,
A technique for reading the data in the memory by the adjustment unit of the recording apparatus main body and adjusting the electric power supplied to the heater according to the elapsed time of mounting the ink container to keep the ink amount of the ink droplet constant regardless of the change in the viscosity of the ink. Is proposed.

[0006]

However, the cost of the ink container, which is a consumable item, increases because it is necessary to attach a memory for recording identification data of the manufacturing date and time of the ink container and the mounting date and time to the recording device to the ink container. As a result, there is a problem that the running cost of printing is raised, a place for accommodating a memory, and a connector for connection with the outside are required, so that the ink container becomes large.

Another problem is that the ink viscosity in the ink container cannot be uniquely estimated only by the mounting time of the ink container. That is, when the ink remaining amount in the ink container decreases due to the consumption of the ink, the solute concentration of the ink sharply rises due to the evaporation of the solvent as the ink remaining amount decreases. As a result, the ink viscosity in the ink container also rises rapidly with the passage of time. As the size of the recording device has been reduced, the ink volume in the ink container has been reduced, and the concentration of solutes such as colorants that make up the ink has been increased to improve printing quality on plain paper. This rapid increase in ink viscosity becomes more remarkable. Further, as shown in FIG. 6, the increase curve of the ink viscosity with respect to the passage of time also differs depending on the difference in the ink consumption speed. in this way,
Even if it is attempted to keep the ink volume of the ink drop constant regardless of the change in the viscosity of the ink by identifying the manufacturing date and time of the ink container and the date and time when the ink container was installed in the recording device, There was a problem in that the desired performance could not be obtained when the number of products decreased.

[0008]

SUMMARY OF THE INVENTION In order to solve such problems, in the present invention, an ink jet type recording head for ejecting ink droplets by receiving ink supply from an ink container, and an ink jet recording head based on a print signal are used. In a recording device including a recording head drive circuit that supplies a drive signal to an ink jet recording head, an ink container attachment / detachment detection means for detecting attachment / detachment of the ink container, and ink based on a signal from the ink container attachment / detachment detection means While resetting the time measurement data by detecting that the container has been replaced, a time measuring means for measuring the mounting duration of the ink container, an ink remaining amount detecting means for detecting the ink remaining amount in the ink container, and The ink droplets ejected from the recording head correspond to the mounting duration and the ink remaining amount in the ink container.
So that the track amount is approximately constant, or if the recording head
Amount of colorant per unit ink droplet ejected from the unit
Is set to be substantially constant, and the driving voltage pulse supplied to the recording head is set so that the clocking means resets the clocking data every time the driving voltage pulse is set to reset the ink from that time point. The duration of mounting the container was measured. Based on the ink viscosity equivalent value data of the means 25, the current ink viscosity equivalent value is calculated, a drive voltage pulse corresponding to the ink viscosity equivalent value is read out from the drive voltage pulse storage means 29 described later, and this drive voltage pulse is read. It is set as an output of the recording head drive circuit 27.

[0009]

With the ink container mounting time and the ink remaining amount in the ink container being entirely controlled by the recording apparatus main body, the ink that is substantially governed by two parameters: the ink container mounting time and the ink remaining amount in the ink container. The drive voltage pulse of the recording head is set in response to the increase in viscosity to increase the ink ejection capacity of the recording head so that the ink amount is constant or the colorant amount per unit ejected ink droplet regardless of the increase in ink viscosity. Causes a constant ink droplet to be ejected.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments.

FIG. 1 shows an embodiment of an ink jet recording apparatus according to the present invention, in which reference numeral 1 indicates
The carriage is connected to the carriage driving motor 3 by the timing belt 2 and is configured to be guided by the guide member 4 and reciprocate in parallel with the platen 5.

On the surface of the carriage 1 facing the recording paper 6, a recording head 7 for ejecting black ink is mounted in a printing area (left side in the drawing), and a recording head 8 for color printing is mounted in the non-printing area side. Each of the recording heads 7 and 8 receives ink from the black ink container 9 and the color ink container 10, respectively, and ejects ink droplets onto the recording paper 6 for printing.

Reference numeral 12 denotes a capping device, in which a cap member 13 for sealing the black ink recording head 7 and a cap member 14 for sealing the color ink recording head 8 are mounted on the same slider, and two tubes are provided. The pump unit 16 composed of a pump is connected via a tube.

Each of the cap members 13 and 14 has a size capable of sealing the nozzle opening surfaces of the recording heads 7 and 8 in one space, and is formed of an elastic material such as rubber into a cup shape. The nozzle openings of the heads 7 and 8 are sealed, and ink is forced from the recording heads 7 and 8 by negative pressure from the pump unit 16 that receives the power of the motor 17 that drives the paper feed roller (not shown) at the time of the ejection capacity recovery operation. It is configured so that it can be discharged.

Further, in the vicinity of the capping device 12,
A cleaner unit 18 which moves up and down by a motor 17 is arranged. By moving these in parallel, it is possible to prevent local thickening and solidification of ink near the nozzle openings.

FIG. 2 is a block diagram showing an embodiment of the present invention, in which reference numeral 20 is an ink container attachment / detachment detection means, which is a fixed contact 21 provided in a frame 19 for accommodating the ink container 9. And the movable contact 22 which is opposed to the movable contact 22 and is displaced by the contact of the ink container 9,
It is configured to output a signal by attaching and detaching (Fig. 3).

Numeral 23 is a time measuring means, which resets the previous time measuring data when the ink container 9 is replaced based on the signal from the ink container attachment / detachment detecting means 20, and continues the mounting state. In this case, the ink container mounting duration time, which has elapsed since the drive voltage pulse was set last time, is measured, and the time data input from the timer means provided in the recording device main body or the host device is acquired. It is configured to calculate the mounting duration time.

Reference numeral 24 is a drive voltage pulse setting means, which is data of the mounting duration time of the time measuring means 23 when the power is turned on, data of the ink remaining quantity of the ink remaining quantity detecting means 28 described later, and ink viscosity described later. An ink viscosity equivalent value at the present time is calculated based on the ink viscosity equivalent value data of the equivalent value storage means 25, a drive voltage pulse corresponding to the ink viscosity equivalent value is read out from a drive voltage pulse storage means 29 described later, and this drive is performed. The voltage pulse is set as the output of the recording head drive circuit 27.

Reference numeral 25 denotes the above-mentioned ink viscosity equivalent value storage means, which is configured to store the ink viscosity equivalent value calculated when the drive voltage pulse was previously set. The ink viscosity equivalent value refers to a numerical value corresponding to the ink viscosity in the ink container 9. Not only the ink viscosity value itself but also a numerical value such as a solvent weight ratio in the ink container 9 may be used as long as it has a one-to-one relationship with the ink viscosity.

Reference numeral 28 denotes an ink remaining amount detecting means for detecting the ink remaining amount in the ink container 9. The remaining ink amount detecting means 28 of the present embodiment determines the amount of ink consumed by the ejection of the ink droplets and the clogging recovery based on the counting of the number of pulse signals for ejecting the ink droplets and the counting of the number of clogging recovery operations. The total amount of consumed ink, which is the sum of the amount of consumed ink, is calculated to calculate the remaining amount of ink in the ink container 9. The remaining ink amount detecting means 28 of this system has a feature that the remaining ink amount can be accurately detected with a simple configuration, as compared with the method of detecting the remaining ink amount mechanically or electrically.

Reference numeral 29 is a drive voltage pulse storage means, which is equivalent to the ink viscosity based on the voltage data (FIG. 5) for the correction necessary to obtain the optimum printing result for the ink viscosity equivalent value which has been investigated in advance. It is configured to store data that defines the relationship between the value and the drive voltage. In this embodiment,
Although the drive voltage pulse is corrected by the voltage, the correction can be performed by the pulse length, and the drive voltage pulse storage unit 29 stores data defining the relationship between the ink viscosity equivalent value and the drive voltage pulse length. It may be configured to be stored.

Reference numeral 26 in the drawing denotes a print control means for controlling the recording head drive circuit 27 based on a print signal from an external device.

Next, the operation of the apparatus thus constructed will be described with reference to the flow chart shown in FIG.

When the power source of the recording apparatus is turned on (step S1), the time keeping means 23 detects the ink container mounting duration time that has elapsed since the last drive voltage pulse was set (step S2). In the next step S3, the ink remaining amount detecting means 28 detects the ink remaining amount in the ink container 9. In step S4, the ink viscosity equivalent value written in the ink viscosity equivalent value storage means 25 is read. The ink viscosity equivalent value is the value in the initial state immediately after the ink container 9 is replaced, and when the ink container 9 is continuously mounted, the ink when the drive voltage pulse is set last time is set. The value is equivalent to the viscosity. In step S5, the driving voltage pulse setting means 24 calculates the current ink viscosity equivalent value based on the three data in steps S2, S3, and S4. Detailed calculation will be described below by taking a case where the solvent is water as a typical example of the ink.

If the ink viscosity with respect to the evaporation rate of water in the ink is measured in advance and the relation of the ink viscosity η with respect to the weight ratio x of water in the ink container is obtained from this data, generally,

[0026]

[Equation 1]

If the weight ratio of water in the ink container 9 is approximated by approximating the numerical formula (a and b are constants obtained by approximation), the ink viscosity in the ink container 9 can be calculated. In this embodiment, for simplicity, the ink container 9
The weight ratio of water content is used as the ink viscosity equivalent value. The weight ratio of water in the ink container 9 at present is

[0028]

[Equation 2]

Is calculated by In Equation 2, as input data, the wearing duration in step S2, step S2
The remaining amount of ink at the present time in 3 and the weight ratio of water in the ink container 9 when the previous drive voltage pulse is set in step S4 are input.

Next, in step S6, the drive voltage pulse setting means 24 stores the drive voltage pulse suitable for the ink viscosity in the ink container 9 at the present time on the basis of the ink viscosity equivalent value calculated in step S5. Means 29
And set as a drive voltage pulse for the recording head drive circuit 27.

When the driving voltage pulse suitable for the ink viscosity in the ink container 9 is set in step S6, step S6 is performed.
In 7, the ink viscosity equivalent value at the time of setting the drive voltage pulse is updated and written in the ink viscosity equivalent value storage means 25. Then, in step S8, the time measuring means 23 resets the mounting duration data which has been measured until the time when the drive voltage pulse was set last time, and in step S9, the time measuring means 23 starts the time measuring operation.

When a print signal is input (step S1)
0), the recording head drive circuit 27 drives the recording head 7 by the drive voltage pulse from the drive voltage pulse setting means 24 (step S11).

Since ink droplets are, of course, ejected by the pressure generated by the pressure generating means provided in the pressure generating chamber, for example, the heating element or the electromechanical conversion element that deforms the pressure generating chamber from the outside, By changing the magnitude of the drive voltage in accordance with the ink viscosity equivalent value, the recording head pressurizes the ink with a pressure corresponding to the ink viscosity at that time, and an ink suitable for printing regardless of the ink viscosity. Eject drops. Further, since the influence of the remaining amount of ink is also input as one of the parameters in the calculation of the ink viscosity equivalent value, an accurate ink amount suitable for printing is obtained regardless of the remaining amount of ink in the ink container 9. Eject ink drops.

When the old ink container 9 is removed from the recording device at the stage when the ink in the ink container 9 is consumed and the ink end is detected, the ink container attachment / detachment detecting means 20 detects the removal of the ink container 9 (step S12). ,
In step S13, the mounting continuation time data from the time when the previous drive voltage was set, which is measured by the time measuring means 23, is reset.

Next, when a new ink container 9 is attached, a signal is output from the ink container attachment / detachment detection means 20 (step S14), and the ink viscosity equivalent value data stored in the ink viscosity equivalent value storage means 25 is initialized. (Step 15). The drive voltage pulse setting means 24 is
The drive voltage pulse is reset based on the data of the ink remaining amount detecting means 28 (step S3) (step S6).
The time measuring means 23 starts the time measuring operation (step S9),
The recording device is in a state of waiting for the input of the print signal (step S10).

(Second Embodiment) The second embodiment is based on the above-mentioned structure, and in a recording head which ejects a plurality of inks having different densities with respect to the same color ink, the inks against the evaporation of the ink solvent due to the difference in the ink densities. Since the change in viscosity with time varies greatly depending on the ink, the drive voltage pulse setting means 24 is configured to set the drive voltage pulse to be supplied to the recording head 7 for each ink, and the change in viscosity of the ink increases. It has an effect that a smooth gradation can be stably maintained regardless of the above.

Further, in the above-mentioned embodiment, the drive pulse setting means 24 is stored in the drive voltage pulse storage means 29 so that the ink amount of the ejected ink droplet becomes substantially constant regardless of the viscosity of the ink. The drive voltage pulse was read out and set as the output of the recording head drive circuit 27.
However, it is also possible to store a drive voltage pulse corresponding to the ink viscosity equivalent value in advance in the drive voltage pulse storage means 29 so that the amount of the colorant per ejected ink drop is substantially constant. Therefore, it is possible to perform image recording with a stable reflection density value on the recording paper regardless of the increase in the viscosity of the ink.

In the above embodiment, the case where the ink container is independently attached and detached has been described as an example. However, the ink container is integrated with the ink container as an ink jet recording head, and ink is supplied to replace the recording head. It is obvious that the invention can also be applied to a recording apparatus using a head-integrated ink cartridge which is performed at the same time.

In the above embodiment, the recording apparatus of the type in which the ink container is mounted on the carriage has been described as an example, but the ink container is installed in the box and the ink is supplied to the recording head by the tube. Can also be applied.

[0040]

As described above, according to the present invention,
Ink container attachment / detachment detection means for detecting the attachment / detachment of the ink container, time measurement data for resetting the time data by the ink container attachment / detachment, ink remaining amount detection means for detecting the ink remaining amount, and attachment continuation Depending on the time and the remaining amount of ink,
So that the ink amount is substantially constant, or the recording head
Colorant per unit ink drop ejected from ink
A drive voltage pulse setting means for setting a drive voltage pulse to be supplied to the recording head is provided so that the amount becomes substantially constant, and the time counting means resets the time measurement data every time the drive voltage pulse is set. Since the mounting duration time from the point in time is measured, the memory for recording the identification data of the cartridge manufacturing date and the mounting date and time is not necessary in the ink jet cartridge, and the ink container and the running cost can be reduced and the ink container can be downsized. . Further, since the recording apparatus main body manages two parameters of the ink container mounting duration and the ink remaining amount in the ink container, no matter what history the increase in the ink viscosity in the ink container changes. Further, even when the ink remaining amount in the ink container becomes small, it is possible to accurately respond to the increase change in the ink viscosity and perform printing with the ink droplet having the optimum ink amount.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing an embodiment of an ink container attachment / detachment detection means.

FIG. 4 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between an ink viscosity in an ink container and a correction amount of a drive voltage required to obtain an optimum printing result.

FIG. 6 is a diagram showing the relationship between the cumulative mounting duration of the ink container after replacement and the viscosity of the ink in the ink container.

FIG. 7 is a diagram showing the relationship between the viscosity of ink and the amount of ink in one drop.

[Explanation of symbols]

1 carriage 7, 8 recording head 9,10 ink container 12 Capping device 13, 14 Cap member 20 Ink container attachment / detachment detection means

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-232438 (JP, A) JP-A-6-286159 (JP, A) JP-A-6-320746 (JP, A) JP-A-6- 286125 (JP, A) JP 7-112531 (JP, A) JP 8-34123 (JP, A) JP 2-3365 (JP, A) JP 58-201665 (JP, A) JP-A-6-344638 (JP, A) JP-A-10-246932 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/175 H04N 1/23 101

Claims (4)

(57) [Claims] 1. A recording comprising an ink jet recording head that receives supply of ink from an ink container and ejects ink droplets, and a recording head drive circuit that supplies a drive signal to the ink jet recording head based on a print signal. In the apparatus, an ink container attachment / detachment detecting means for detecting attachment / detachment of the ink container, and resetting of the clock data by detecting exchange of the ink container based on a signal from the ink container attachment / detachment detecting means, and the ink Time keeping means for measuring the mounting duration of the container, ink remaining amount detecting means for detecting the remaining ink amount in the ink container, and the recording head corresponding to the mounting duration time and the remaining ink amount in the ink container.
So that the ink volume of the ink droplets ejected from the printer is approximately constant
The provided with a drive voltage pulse setting unit that sets a driving voltage pulse supplied to the recording head, the clock means is the ink container from that point to reset the timing data for each of setting the drive voltage pulse An ink jet recording apparatus, which is characterized by measuring a mounting duration time. 2. The ink is supplied from the ink container.
Inkjet recording head that ejects ink droplets and printing
Driven to the inkjet recording head based on a signal
Recording apparatus including a recording head drive circuit for supplying a signal
At Ink container attachment / detachment detection hand for detecting attachment / detachment of the ink container
And the signal from the ink container attachment / detachment detection means.
Detects that the ink container has been replaced and
Reset and reset the ink container installation time
And a remaining amount of ink in the ink container
Ink remaining amount detecting means for detecting the
Corresponding to the remaining amount of ink in the ink container, the recording head
Coloring of ink droplets ejected from a unit
The drive that supplies the recording head so that the amount of the agent becomes substantially constant.
Equipped with drive voltage pulse setting means for setting dynamic voltage pulse
AndThe timing means counts each time the drive voltage pulse is set.
Time data is reset and the ink container is installed from that point.
Inkjet characterized by measuring the wear duration
Recording device. 3. The remaining ink amount detecting means detects the remaining amount state of the ink container based on the counting of the number of pulse signals for ejecting ink droplets and the counting of the number of clogging recovery operations. The inkjet recording apparatus according to claim 1 or 2 . Wherein said driving voltage pulse setting means, and sets a driving voltage pulse to be supplied to said recording head in response to the concentration of the ink, the ink jet recording apparatus according to claim 1 or 2 wherein.