JP3497112B2 - 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 inkjet recording device.

[0002]

2. Description of the Related Art An ink jet recording apparatus such as an ink jet printer is light in weight, generates little noise, and is capable of high speed recording without requiring special fixing on plain paper. Have. Therefore, in recent years, the digitalization of OA equipment has rapidly progressed, and the demand for color image output has increased, so that low-cost color ink jet printers have become widespread, along with digital color copying machines and color laser printers. Are being developed.

In general, an ink jet printer has an ink jet head formed with an ink tank and a large number of ink ejection ports for ejecting ink mounted on a carriage.
A drive system is used in which the carriage is scanned in a direction (main scanning direction) at a right angle to the conveyance direction of a recording medium such as recording paper. However, in such a method, a large capacity of the ink tank is required as the amount of printing increases, and as a result, the weight of the carriage becomes heavy. A method has been proposed in which the carriage is lightened by supplying ink from the main tank to the sub tank and the movement control of the carriage is easily performed by providing the main body of the apparatus with ink.

For example, in the device described in Japanese Patent Laid-Open No. 5-138899, an ink inlet for supplying ink for each color of cyan, yellow, magenta, and black is provided in a fixed ink tank (main tank). A joint nozzle, an arm, a solenoid, etc. are provided, and when the carriage moves to the ink supply position, the joint nozzle is extended and ink is supplied to the inkjet head. An ink tank (sub-tank) in the inkjet head is provided with an ink empty sensor and an ink full sensor. The solenoid is turned on and off based on the detection results of these sensors to expand and contract the joint nozzle. I do.

Further, in the apparatus described in Japanese Patent Laid-Open No. 10-235892, ink is intermittently supplied from a storage container outside the carriage to the print cartridge without removing the ink jet print head from the carriage.
Therefore, the storage container outside the carriage is connected to the needle valve structure supported by the refill station housing by a short flexible tube for each color of ink. When refilling ink, the lever to which the refill station housing is attached rotates and the needle valve structure engages the refill port of the cartridge.

The needle valve structure is provided with a hollow needle having a plurality of openings formed at the ends thereof, and a slide valve collar that seals around the needle is biased to a valve closed position by a spring, and printing is performed. When any one of the ink volumes in the cartridge internal storage container falls below a threshold value, the needle valve structure engages the refill port of the cartridge, the slide valve collar pushes the needle up, and the needle tip slides into the port opening. Ink is supplied to all of the plurality of print cartridges at the same time.

However, the above-mentioned Japanese Patent Laid-Open No. 5-13889.
In the device described in Japanese Patent Laid-Open No. 9, when ink remains in the joint nozzle that supplies ink and is left for a long time,
Evaporation may clog the tip of the joint nozzle. Further, in the device described in the above-mentioned JP-A-10-235892, the needle valve structure for supplying ink and the structure of the supply port of the cartridge are complicated, and the device described in the above-mentioned JP-A-5-138899. Similarly, the hollow needle tip may be clogged.

In the ink jet printer,
In the drive system in which the inkjet head is scanned in a direction (main scanning direction) perpendicular to the transport direction of the recording medium such as recording paper, it is necessary to quickly reverse the scanning direction of the inkjet head at both ends of the recording medium. The inkjet head is controlled to be decelerated and then accelerated.

At this time, the deceleration of the ink jet head
A large force is generated in the device (ink jet printer) due to a force acting in the opposite direction depending on the acceleration. This vibration
Not only the quality of the printed image is deteriorated, but also the noise makes the user uncomfortable. As a method for solving such a problem, in JP-A-8-276577, an inkjet head is configured by reciprocating a plurality of inkjet heads arranged side by side in the sub-scanning direction at different phases in the main scanning direction. There has been proposed a method of suppressing the vibration due to the scanning. Specifically, at least one pair of inkjet heads are provided, and a permanent magnet is attached to each inkjet head, and one permanent magnet and the other permanent magnet are arranged so that the magnetic fields act in opposite directions on the driving electromagnetic coil. However, a pair of inkjet heads are driven in opposite phases by one common electromagnetic coil.

However, in each of the above-mentioned ink jet heads, the amounts of both inks are almost the same in the initial stage, but the amount of ink used changes depending on the amount of each ink used with the passage of time. There is a difference in weight between the inkjet heads. Therefore, even if a plurality of inkjet heads are scanned in different phases,
Since the force (reaction force) generated in each inkjet head is different, it is difficult to offset this force.

In the conventional ink jet recording type recording apparatus, as a method of detecting the ink remaining amount stored in the ink storing means, a method of detecting the weight of the ink storing means or a sensor installed in the ink storing means is used. The method of detection is used. In the device described in Japanese Patent Application Laid-Open No. 6-143610, two sensors are provided in the ink storage means in the vertical direction to detect the remaining amount of ink, and the ink surface vibrates while the ink storage means is operating. However, the remaining amount can be accurately detected without being affected by the influence, and the remaining amount can be detected without interrupting the printing operation even during printing.

However, in the above-described method for detecting the remaining ink amount, the ink storage means is provided with two sensors for detecting the remaining ink amount, the states of the two sensors are collated separately, and the results thereof are obtained. On the basis of this, after frequently exchanging data with the memory, the out-of-ink state is displayed, and there is a problem that it takes time to detect the remaining amount of ink. In addition, in the method of detecting the remaining amount by providing only one sensor for detecting the remaining amount of ink in the ink storage means, it is difficult to perform highly accurate detection of the remaining amount of ink because it is affected by the vibration of the ink surface. Is.

The present invention has been made in view of the above problems, and provides an ink jet recording apparatus capable of efficiently and stably supplying ink to a print head to form a high quality image. The purpose is to do.

[0014]

According to the invention of the first aspect, a print head for ejecting ink droplets onto a recording medium, a sub tank for storing ink to be supplied to the print head, a print head and a sub head. A print head moving means for mounting the tank to move the print head between the printing position and the return position, a main tank with which the sub tank engages at the return position of the print head, and an ink for the main tank at the return position An ink transfer means for transferring to the tank, wherein the ink transfer means is
The excess ink is returned from the sub tank to the main tank to make the liquid level of the sub tank constant and the sub tank holds ink.
It has an elastically deformable ink holder inside,
Ink in the sub tank near the tank or the main tank
A pressing member capable of pressing the body is provided, and the ink holding body is
When the sub tank is engaged with the main tank, the pressing member
The liquid surface of the ink that is pressed and held inside the ink holder is
When the sub tank is lifted and the sub tank separates from the main tank, the pressing part
Pressed by the material is released and restored,
Due to the negative pressure generated, the ink in the sub tank is moved to the ink holder.
An ink jet recording apparatus is provided, characterized in that to absorb the. According to the present invention, the liquid level of the sub-tank can be kept constant, and ink droplets can be ejected from the print head in a stable state.

In the ink jet recording apparatus of the present invention,
The ink transfer means includes a conduit whose tip is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and an elastic member whose one end is connected to the base end of the conduit and whose other end is opened in the main tank. There is a configuration consisting of a deformable tube and an ironing pump that draws the ink in the main tank to the sub tank by squeezing the tube in the forward and reverse directions with a rotor and then sucking the excess ink in the sub tank into the main tank. . In this structure, an ironing pump is used in which a rotor is driven to rotate by a pump motor capable of forward and reverse rotation of a flexible tube arranged along an arc-shaped wall surface of a pump casing. One end of the tube is connected to the proximal end of the needle, which is a conduit, and the other end is connected to the main tank. First, the pump motor is rotated in the normal direction, a predetermined amount of ink is ejected into the sub tank through the needle, and then is rotated in the reverse direction.
Excess ink is returned from the sub tank to the main tank. As described above, since one pump is used to control the ink surface in the sub-tank to be constant by the normal / reverse rotation of the pump motor, the number of parts can be reduced. Further, when sucking ink, since the suction operation is performed for a certain time even after the liquid surface of the ink reaches a predetermined position, the ink remains in the needle and the needle is not clogged due to being left for a long time. be able to.

In the ink jet recording apparatus of the present invention,
The ink transfer means has at least two conduits whose tips are inserted into and removed from the auxiliary tank when the auxiliary tank is engaged with the main tank, and one end is connected to each base end of these conduits and the other end is main. At least two elastically deformable tubes that are opened in the tank, and while squeezing these tubes in one direction by the rotor to discharge the ink from the main tank to the sub tank, at the same time, the excess ink in the sub tank is discharged to the main tank. An example is a configuration including an ironing pump that sucks into. In this configuration, two conduits (needle), that is, an ink discharge needle and an ink suction needle are used, and two tubes respectively connected to the respective base ends of these needles are unidirectionally driven by a rotor to squeeze and pump. One is used. That is, by driving and rotating the rotor in one direction, ink is supplied from the main tank to the sub tank, and at the same time, excess ink in the sub tank is sucked into the main tank. With this configuration, it is possible to supply a fixed amount of ink to the sub tank in a short time without performing control such as liquid level detection in the sub tank. Also,
In the above structure, a plurality of sets of two tubes, which are respectively connected to the respective base ends of the ink discharge needle and the ink suction needle, are laminated along the arc-shaped wall surface of the pump casing,
The base pump may control the supply / suction of a plurality of inks. With this configuration, the number of parts can be significantly reduced.

In the ink jet recording apparatus of the present invention,
The ink transfer means has a conduit whose tip is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and an elastic member whose one end is connected to the base end of the conduit and the other end is opened in the main tank. It consists of a deformable tube and a squeezing pump that makes the tube unidirectional by a rotor.
Using the basic ironing pump, one ironing pump irrigates one tube with the rotor in one direction to discharge the ink from the main tank to the sub tank, and the other ironing pump irrigates the other tube with the rotor in one direction. A configuration may be adopted in which the excess ink in the sub tank is sucked into the main tank. In this case, two ironing pumps are used. An ink discharge needle is connected to one pump to supply ink from the main tank to the sub tank, and an ink suction needle is connected to the other pump to suck excess ink in the sub tank. Done. In this way, by using individual pumps, ink supply and suction can be controlled independently, and the degree of freedom of control can be increased. Further, as in the case described above, by stacking a plurality of sets of tubes connected to the ink discharge needles and tubes connected to the ink suction needles along the arc-shaped wall surface of each pump housing, two groups are formed. It is possible to supply and suction multiple inks with the pump, and reduce the number of parts.

In the ink jet recording apparatus of the present invention,
The ink transfer means discharges the ink in the main tank to the sub tank until a liquid level is formed above the tip of the conduit inserted in the sub tank, and the liquid level of the ink in the sub tank is at least the tip of the conduit. Since the ink in the sub-tank is sucked into the main tank until the temperature drops to 0, it is possible to control the ink liquid level in the sub-tank with a simple mechanism without using a liquid level sensor or the like.

In the ink jet recording apparatus of the present invention, the ink holding member and the pressing member as described above are provided.
By that, the ink holding member (e.g., sponge)
However, it is once compressed, and in this state, a predetermined amount of ink is supplied by any of the above-mentioned ink transfer means. Next, when the compression is released, a negative pressure is generated inside the ink holder,
This negative pressure prevents ink from leaking from the nozzles of the print head. In this way, by combining the compression / decompression operation of the ink holder and the ink supply method by the above-mentioned ink transfer means, it is possible to always supply a fixed amount of ink to the sub-tank and prevent ink from leaking from the nozzle. Can be prevented.

In the ink jet recording apparatus of the present invention,
The sub-tank is provided with a flexible deforming member on the outer surface thereof, and the pressing member protrudes from the main tank toward the sub-tank deforming member for pressing and deforming the ink holding body via the deforming member. An example of the configuration is a projection. The main tank is disposed at the return position of the print head and engages with the sub tank mounted on the print head when the print head moves to the return position. At this time, the projection body, which is a pressing member provided in the main tank or in the vicinity of the main tank, presses the deformable member of the sub tank, and the sponge in the sub tank is compressed. The compression of the sponge is released when the print head moves away from the return position. As described above, since the drive of the print head is used instead of providing a new drive means as a mechanism for compressing or decompressing the sponge in the sub tank, the sponge can be easily compressed / decompressed with a simple structure. It can be performed. Further, the pressing member may be a conduit that is inserted into and removed from the sub tank, and the conduit may directly press the upper portion of the ink holder. In this case, the pressing member for compressing the ink holding body (sponge) is composed of a conduit (needle) for supplying and sucking ink, and the sponge is compressed and decompressed by inserting and removing the needle. With this configuration, it is not necessary to provide the above-mentioned pressing member or the sub-tank deforming member, and the device configuration is simplified. Further, the sub-tank can be formed of a rigid body, and the degree of freedom in selecting a container can be increased.

In the ink jet recording apparatus of the present invention,
When the print head returns to the return position, the swing arm, which has one end holding the conduit and the other end being pivotally supported, rotates the swing arm forward and inserts the conduit into the sub-tank for printing. An example is a configuration in which the swing arm is reversed when the head is separated from the return position and is supported by a conduit insertion / extraction mechanism that extracts the conduit from the sub tank. The conduit (needle) is fixed to a swing arm whose other end is pivotally supported, and when the print head returns to the return position, it is rotated forward and the needle is inserted into the sub tank. When the print head moves away from the return position, the swing arm is reversed and the needle is withdrawn from the sub tank. In this way, the needle insertion and removal can be reliably performed by interlocking with the drive of the print head. Further, this conduit insertion / removal mechanism may be used for compression / decompression of the sponge described above.

In the ink jet recording apparatus of the present invention,
The two conduits in the ink transfer means are an ink discharge conduit and an ink suction conduit, which are integrally formed. With this configuration, the conduit can be easily inserted into and removed from the sub tank, and the time for supplying the ink to the sub tank can be shortened. The ink transfer means is arranged in the flow path between the ink discharge conduit or ink suction conduit and the ironing pump, and is equipped with flow path cross-sectional area adjusting means for adjusting the cross-sectional area of this flow path by expansion and contraction. The path cross-sectional area adjusting means is formed such that the expansion / contraction amount thereof is larger than the flow path volume from the flow path cross-sectional area adjusting means to the tip of the ink discharge conduit / ink suction conduit. The flow passage cross-sectional area adjusting means is mainly composed of a bellows having a stretchable portion. The flow path cross-sectional area adjusting means is compressed in advance when the ink is supplied from the main tank to the sub tank, and is expanded when the ink supply is completed. The amount of change (expansion / contraction amount) in the flow passage cross-sectional area of the bellows is measured from the outlet of the bellows to the tip of the ink ejection needle (in the needle in which the ink ejection needle and the ink suction needle are integrated,
It is configured to be larger than the volume of the flow path (up to the tip of these needles), and at the end of ink supply,
When the bellows is expanded, the ink remaining in the ink ejection needle or the ink suction needle is collected in the bellows. In this way, since ink does not remain in the ink discharge needle or the ink suction needle, it is possible to prevent clogging of these needles.

It is preferable that the flow path cross-sectional area adjusting means is driven and controlled in synchronization with the print head moving means. For example, if the flow path cross-sectional area adjusting means is configured so that the reduction control is performed at least after it is detected that the conduit is inserted into the sub tank, the ink remaining in the conduit is discharged to a place other than the sub tank. Can be prevented. The sub tank is composed of a plurality of ink tanks, and an ink remaining amount detecting means for generating a signal when the ink remaining amount in any one of these sub tanks is low is provided. As the ink remaining amount detecting means, for example, a method of counting the number of dots ejected from the nozzles of the print head by software can be used. The detection result is compared with a threshold value, and when the threshold value is not more than the threshold value, ink is supplied from the main tank to the plurality of ink tanks of the sub tank. In this case, the ink remaining amount detecting means does not have to be provided in each ink tank, and it is sufficient that the remaining amount of ink in any one of the ink tanks is detected. It is possible to control so that a constant amount of ink is supplied.

In the ink jet recording apparatus of the present invention,
Further provided is a flow path opening / closing means which is arranged in a flow path connecting the sub tank and the print head and which is opened / closed in accordance with the insertion / extraction of the conduit to / from the sub tank. A flow path (ink supply path) that connects the sub tank and the print head is provided between the sub tank and the print head. The ink supply path is provided with a valve as a flow path opening / closing means, and a conduit (needle) is inserted / removed. The opening / closing operation is controlled in accordance with. The valve is opened when the print head is performing a printing operation, and is closed when ink is supplied to the sub tank, that is, when the needle is inserted into the sub tank. When ink is supplied, the sponge is compressed to generate a positive pressure as described above, but since the valve is closed, the positive pressure prevents ink from leaking from the nozzle of the print head. Further, since the opening / closing operation of the valve is controlled according to the insertion / removal of the needle, the opening / closing operation can be reliably performed.

In the ink jet recording apparatus of the present invention,
The conduit is composed of a bent tube and an opening formed in the vicinity of the bent portion of the tube. One side of the tube is used as an ink discharge conduit and the other side is used as an ink suction conduit. The conductance of the ink supply conduit is Cin, the conductance of the ink suction conduit is Cout, and the conductance of the opening is C.
If op is set, Cop> Cout ≧ Cin is satisfied. Conduit (needle) that supplies and sucks ink
In this case, one thin tube (tubular body) is bent, and an opening is provided in the vicinity of the bent portion. That is, in this configuration, ink is supplied from the opening and excess ink is sucked. Here, the conductance of the opening is Cop, and the conductance of the ink discharge needle of the bent thin tube is Ci.
n, and the conductance of the ink suction nidle is Cout, the needle is configured to satisfy Cop> Cout ≧ Cin. With this configuration, it is possible to supply and suck ink from one opening, and the conductance Cout of the ink suction needle is set to be equal to or larger than the conductance Cin of the ink ejection needle. Therefore, the excess ink in the sub tank can be sucked without remaining, and a constant amount of ink can be always supplied to the sub tank.

According to the invention of the second aspect, a print head for ejecting ink droplets onto a recording medium, a sub tank for storing ink supplied to the print head, and a print head and a sub tank are mounted for printing. The print head moving means for moving the head between the print position and the return position and the sub tank
The main tank that engages at the return position of the print head and the return
Ink transfer that transfers the ink from the main tank to the sub tank at the position
And a means for connecting the sub tank and the print head.
Placed on the road and closed when the conduit is inserted or removed from the sub tank
Ink transfer means further comprising flow path opening / closing means for opening
Returns excess ink from the sub tank to the main tank
Keep the liquid level in the sub tank constant and keep the ink transfer means
When the hook engages with the main tank, the tip
The conduit to be inserted / removed and one end connected to the proximal end of the conduit and the other
Elastically deformable tube with an end open into the main tank
And squeeze the tube forward and backward with the rotor
Excess ink in the sub tank after ejecting ink
Do not use an ironing pump that draws minute ink into the main tank.
An ink jet recording apparatus is provided, characterized in that that. According to the present invention , the ink can be efficiently supplied to the print head.
Ink supply that enables stable and stable supply of high-quality images.
You can bring a wet recording device.

According to the invention of the third aspect, a recording medium
The print head that ejects ink drops to the body and the print head
The sub tank that stores the ink that is supplied and the print head and
And a sub-tank are installed to move the print head to the print position and return position.
The print head moving means for moving between the
The main tank that engages at the return position of the print head and the return
Ink transfer that transfers the ink from the main tank to the sub tank at the position
And a means for connecting the sub tank and the print head.
Placed on the road and closed when the conduit is inserted or removed from the sub tank
Ink transfer means further comprising flow path opening / closing means for opening
Returns excess ink from the sub tank to the main tank
Keep the liquid level in the sub tank constant and keep the ink transfer means
When the hook engages with the main tank, the tip
At least two conduits to be inserted and removed and one of these conduits at one end
It is connected to each base end of the pipe and the other end is opened in the main tank.
At least two elastically deformable tubes and these
Of the main tank by squeezing the tube of
Surplus of the sub tank at the same time while ejecting ink to the sub tank
Do not use an ironing pump that draws minute ink into the main tank.
An inkjet recording device characterized by
It According to the present invention, the ink can be efficiently supplied to the print head.
Ink supply that enables stable and stable supply of high-quality images.
You can bring a wet recording device.

According to the invention of the fourth aspect , a print head for ejecting ink droplets onto a recording medium, a sub tank for storing ink supplied to the print head, a print head and a sub tank are mounted for printing. The print head moving means for moving the head between the print position and the return position and the sub tank
The main tank that engages at the return position of the print head and the return
Ink transfer that transfers the ink from the main tank to the sub tank at the position
And a means for connecting the sub tank and the print head.
Placed on the road and closed when the conduit is inserted or removed from the sub tank
Ink transfer means further comprising flow path opening / closing means for opening
Returns excess ink from the sub tank to the main tank
Keep the liquid level in the sub tank constant and keep the ink transfer means
When the hook engages with the main tank, the tip
The conduit to be inserted and removed and one end connected to the base end of the conduit and the other end
Is an elastically deformable tube opened in the main tank,
Rotate the tube in one direction with the rotor and
Consisting of at least the two ironing pumps,
One iron pump pumps one tube to the rotor.
Squeeze in one direction to eject ink from the main tank to the sub tank
The other tube by the other ironing pump.
Squeeze in one direction to remove excess ink from the sub tank
An ink jet recording apparatus is provided which is characterized by sucking into a tank . With this invention, the print head is
To efficiently and stably supply high-quality images.
Can bring possible inkjet recording device
It

According to the invention of the fifth aspect, a recording medium
The print head that ejects ink drops to the body and the print head
The sub tank that stores the ink that is supplied and the print head and
And a sub-tank are installed to move the print head to the print position and return position.
The print head moving means for moving between the
The main tank that engages at the return position of the print head and the return
Ink transfer that transfers the ink from the main tank to the sub tank at the position
And a means for connecting the sub tank and the print head.
Placed on the road and closed when the conduit is inserted or removed from the sub tank
Ink transfer means further comprising flow path opening / closing means for opening
Returns excess ink from the sub tank to the main tank
Keep the liquid level in the sub tank constant and keep the ink transfer means
Liquid level is formed above the tip of the conduit inserted in the
Ink from the main tank to the sub tank
The ink level in the tank must be at least down the tip of the conduit.
The ink in the sub tank is sucked into the main tank until
An inkjet recording device is provided. From this
The bright, efficient and stable ink flow to the print head
Inkjet recording that can be supplied and enables high-quality image formation
The device can be brought.

According to the invention of the sixth aspect, a recording medium
The print head that ejects ink drops to the body and the print head
The sub tank that stores the ink that is supplied and the print head and
And a sub-tank are installed to move the print head to the print position and return position.
The print head moving means for moving between the
The main tank that engages at the return position of the print head and the return
Ink transfer that transfers the ink from the main tank to the sub tank at the position
And a means for connecting the sub tank and the print head.
Placed on the road and closed when the conduit is inserted or removed from the sub tank
Ink transfer means further comprising flow path opening / closing means for opening
Returns excess ink from the sub tank to the main tank
Make sure that the liquid level in the sub tank is constant and that the sub tank
One of these sub-tanks
A signal that generates a signal when the remaining ink level is low
Ink jet characterized by having a remaining amount detecting means.
A recording device is provided. According to this invention, the print head
Supplies ink efficiently and stably to the high quality image
To provide a printable inkjet recording device
it can.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an ink jet recording apparatus of the present invention will be described below with reference to the drawings. The present invention is not limited to these. [First Embodiment] In the first embodiment, the ink transfer means includes a conduit whose tip is inserted into and removed from the sub tank when the sub tank engages with the main tank, and one end of which is a base end of the conduit. An elastically deformable tube that is connected and has the other end opened into the main tank, and after the tube is squeezed by the rotor to eject the ink from the main tank to the sub tank, or at the same time when the ink is ejected, the surplus of the sub tank And an ironing pump for sucking the ink of FIG.

FIG. 1 is a perspective view showing an overall construction of an ink jet printer as an ink jet recording apparatus according to an embodiment of the present invention. The inkjet recording apparatus 200 includes a print head 2 that ejects ink droplets onto a recording medium, a sub tank 3 that stores ink supplied to the print head 2, and a base 4 that mounts the print head 2 and the sub tank 3. , A print head moving means 5 for moving the print head 2 mounted on the base 4 together with the sub tank 3 between the print position and the return position, and the main tank 6 with which the sub tank 3 engages at the return position of the print head 2. And an ink transfer means 7 for transferring the ink in the main tank 6 to the sub tank 3 at the return position.
(Not shown) and a main body case 10 that supports them are mainly configured.

The base 4 mounts the sub-tank 3 and the print head 2 arranged below the sub-tank 3, and moves the print head extending in the main scanning direction (the arrow X direction in the drawing) with respect to the recording medium. The feed shaft 51 as the means 5 and the positioning means 54 for keeping the distance between the print head 2 and the recording medium constant.
Is slidably supported by. Further, the base 4 is stretched in parallel with the feed shaft 51, and the timing belt 53 driven by the drive means 52 drives the feed shaft 51.
Is used as a guide to drive the displacement in the main scanning direction. The feed shaft 51, the positioning means 54, and the driving means 52 are supported by the main body case 10.

The above recording medium is fed from the paper feeding section 11 in the sub-scanning direction (direction of arrow Y in the figure), the base 4 moves in the direction of arrow X, which is the main scanning direction, and the mounted print head. Two
Thus, image formation is performed on the recording medium. The recording medium is provided in the paper feed unit 11, is fed one by one by a paper feed roller (not shown), and is supplied below the print head 2 by a conveyance roller (recording medium conveyance means) 182. The recording medium on which image formation has been completed by the print head 2 is ejected to the paper ejection unit 12. The base 4 feeds the print head 2 to the feed shaft 5 when the print head 2 is not performing a printing operation.
1 is moved to a return position where it rests near one end. A main tank 6 is provided near the return position so as to face the sub tank 3 mounted on the base 4.

The sub-tank 3 and the main tank 6 before the return position are shown enlarged in the plan view of FIG. 2 and the front view of FIG. The sub-tank 3 has a plurality of colors, for example, C (cyan), M (magenta), Y (yellow), K (black), and L.
Ink tanks for 6 colors of C (light cyan) and LM (light magenta) are respectively provided. The ink tank may be an ink tank for four colors of cyan, magenta, yellow, and black. The ink tank of the present invention is an ink container that constitutes the sub-tank 3 and the main tank 6, and is one independent tank itself or a plurality of independent tanks that partition the inside of one independent tank. Means one of the rooms.

Immediately before the return position of the print head 2, the return position becomes the maintenance section, and the print head 2
A cleaner blade 13 is provided upright from the main body case 10 to wipe off dirt on the head portion by coming into contact with the nozzle when moving to the return position. At the return position, the cap 14 is provided to prevent the ink from drying and becoming dirty.
Is attached to the nozzle. Below the base 4 in the figure,
A base position detecting means 100, which will be described later, is arranged.

An example of the construction of the print head 2 and the sub tank 3 is shown in FIGS. 4 and 5 both show external perspective views as seen from the recording medium side. Print head 2
Has respective nozzles 21 for ejecting ink, which are provided corresponding to the ink tanks of the respective colors described above, and each nozzle 21 is arranged so as to face a recording medium such as paper. In the embodiment shown in FIG. 4, the ink tanks of the respective colors which are thin and make up the sub-tank 3 are arranged in the sub-scanning direction (Y direction in the drawing), and the respective nozzles 21 are arranged at the bottom of each ink tank. The sub tank 3 is scanned in the X direction orthogonal to the row of the nozzles 21 arranged in the sub scanning direction.

In the embodiment shown in FIG. 5, the ink tanks having the same size in the upper portion and the bottom portion are arranged in the sub-scanning direction (Y direction in the drawing), and the respective nozzles 21 are arranged below the ink tanks. The sub tank 3 is in the main scanning direction (X direction in the figure)
The scanning is performed in the X direction parallel to the row of the nozzles 21 arranged in line. The nozzle 21 in each of the above-described embodiments is connected to an ink tank via an ink supply passage 22 described later. It should be noted that each of the ink tanks in the above-described embodiments is provided with a deformable member 35 described later (not shown in FIG. 4, but the deformable member 35 is provided on the surface facing the row of the nozzles 21). Exist).

The structure of the print head 2 and the ink discharge operation will be described with reference to the sectional view of FIG. FIG. 6A shows a state when not operating, and FIG. 6B shows a state when operating. Print head 2
Is composed of an ink supply path 22 and a piezoelectric vibrator 23. The ink supply path 22 is formed in parallel with the recording medium. A filter 24 is provided in the ink supply path 22 and the tip of the filter 24 is closed to form an ink pressure chamber 25. In the ink pressure chamber 25, the nozzle 21 is formed on the side facing the recording medium, and the piezoelectric vibrator 23 is arranged on the side opposite to the nozzle 21.

The ink supply path 22 is a parallel tube path having an inner diameter of several tens of μm, and when not in operation, as shown in FIG. When a voltage according to the image signal is applied to the piezoelectric vibrator 23, as shown in FIG.
Bends toward the ink pressure chamber 25 and presses the ink pressure chamber 25 to generate pressure inside. The pressure causes the ink 30 to be ejected from the nozzle 21.

When the application of the voltage to the piezoelectric vibrator 23 is completed, the piezoelectric vibrator 23 curved in the direction of the ink pressure chamber 25 returns to the original state, and the restored volume of ink is supplied from the ink supply path 22. Then, it returns to the initial state. By repeating the above operation, an image corresponding to the image signal is formed on the recording medium. The above is the description of the case where the piezo-vibrator 23, which is one of the piezoelectric elements that is deformed by voltage application, is used. However, a method of rapidly heating the ink and ejecting the ink by bubbles generated at that time is also taken. Good.

FIG. 7 is a perspective view showing the appearance of the main tank 6, the sub tank 3, and the ink transfer means 7, and FIG. 8 is a side sectional view thereof. 9 is a perspective view showing a part of the pump 70 by cutting away, and FIG. 10 is a horizontal sectional view of the pump 70. In FIG. 7 and FIG. 8, the ink transfer means 7 is a pump 70 arranged above the main tank 6.
And a needle 8 as a conduit.

At the bottom of the main tank 6, an ink remaining amount detecting means 61 for detecting the remaining amount of ink is provided. As the remaining ink amount detecting means 61, for example, a known reflective sensor that optically detects the amount of ink, such as a photo interrupter, is used. The remaining ink amount detecting means 61
May be provided on the side surface (right side in FIG. 8) of the main tank 6. Further, on the side surface of the main tank 6, a pressing member 62 capable of pressing an ink holding body described later in the sub tank 3 via the deforming member 35 projects toward the deforming member 35 of the sub tank 3. The pressing member 62 may thus be formed integrally with the main tank 6, or in the vicinity of the main tank 6,
That is, the side surface of the storage container that the main tank 6 stores or these may be provided separately. Any structure can be applied as long as the pressing member 62 presses and deforms the ink holding body via the deforming member 35 when the sub tank 3 is engaged with the main tank 6. The pump 70 is the main tank 6
In addition, when the sub tank 3 is engaged with the main tank 6 provided for each of a plurality of inks of different colors, the tip of the needle body 81 enters the sub tank 3, and then the main motor 6 is driven by the pump motor 71. The stored ink is injected into the sub tank 3 via the needle body 81. Pump motor 7
1 is a pulse motor, for example.

As shown in FIGS. 9 and 10, in the pump 70, the flexible tube 9 arranged along the arc-shaped wall surface 72 of the pump casing is rotationally driven by the pump motor 71 (not shown). An ironing pump that is pressed by the rotor 73 is used, one end of the tube 9 is connected to the proximal end of the needle 8, and the other end of the tube 9 opens near the bottom of the main tank 6. The ink flows in the normal direction of the pump motor 71 (see FIG. 10).
Discharge from the main tank 6 side to the needle 8 side (rotation in the counterclockwise direction in the arrow) (hereinafter referred to as "discharging operation"), and the needle is caused by the reverse rotation of the pump motor 71 (rotation in the arrow direction in FIG. 10). It is sucked from the 8 side to the main tank 6 side (hereinafter referred to as "suction operation"). in this way,
The input end P9i and the output end P9o of the tube 9 change depending on the rotation direction of the pump motor 71.

FIG. 11 is a vertical sectional view showing a specific structure of the needle 8. In the needle 8, the needle advance / retreat mechanism 1
40 allows the needle body 81, to which one end of the tube 9 is connected, to enter / retract in the holding member 82 extending from the pump 70 in the axial direction thereof. That is, a rack gear 83 fixed to the outer peripheral surface of the needle body 81 in the axial direction and a pinion gear 84 pivotally supported by the holding member 82 are provided, and the pinion gear 84 is normally / reversely rotated by a drive system (not shown). The tip of the needle body 81 is moved back and forth.

FIG. 12 shows a needle advancing / retreating mechanism 141 according to another embodiment of the present invention. In the needle advancing / retreating mechanism 141, a needle 89 (corresponding to the needle main body 81) bent at the tip portion is provided with the tube 9 via the flexible tube 151 or in the pump 70.
(Including 91 to 96 described later) is directly connected,
Moreover, the needle 89 is attached to the shaft 153 via the support member 152.
It is attached to one end of an arm 154 that is swingable around.

The pinion gear 15 is attached to the other end of the arm 154.
The rack gear 156 is attached to the arm 154 so as not to be rotatable, and the pinion gear 155 is displaced by being pushed by the sub tank 3 when the base 4 is returned to the return position.
Are in mesh. The rack gear 156 is urged toward the base 4 by a biasing means (not shown). In the above, the support member 152, the arm 154, and the pinion gear 1
Reference numeral 55 constitutes a swing arm, and the pinion gear 155 / rack gear 156 and bias means constitute a conduit insertion / removal mechanism.

When the base 4 is located at a position other than the return position, the needle advancing / retreating mechanism 141 causes the rack gear 156 to move the rack gear 156 to the base 4 as shown in FIG. 12 (a).
The arm 154 is brought into contact with one locking member 157 so that the tip of the needle 89 is upward. When the base 4 is stopped at the return position, as shown in FIG. 12B, the rack gear 156 is displaced by being pushed by the protrusion 156a of the base 4 against the bias means.
As a result, the arm 154 is inserted into the sub tank 3 from the opened / closed member 34, and then the arm 154 comes into contact with the other locking member 158 and stops.

On the other hand, on the upper surface of the sponge 33 which is the ink holding member in the sub tank 3, the elastic sheet 3 having air permeability is provided.
9 is provided. The elastic sheet 39 is made of cloth, for example, and when the needle 8 comes into contact with it, the pressing member 6 is pressed.
Instead of 2, it has a function of compressing the sponge 33. Therefore, in this example, the deformation member 3 on the side wall of the sub tank 3
5 and the pressing member 62 extending from the main tank 6 need not be provided.

By thus compressing the sponge 33 with the needle 89 instead of the pressing member 62, the device structure can be simplified. Further, the sub tank 3 does not need to be deformed, and the degree of freedom in selecting the container can be increased by using a rigid material as the container of the sub tank 3. The form in which the sponge 33 is compressed by the needle 89 without using the pressing member 62 can also be realized by using the configuration of the needle 8 shown in FIG. The needle advancing / retreating mechanism 140/141 is a needle 8 in which the above-described ink ejection and suction are performed using one needle main body 81, and an ink ejection needle 85 and an ink suction needle 86 described later are integrated. 8 can be applied. In the above, using the needle body mechanism 141, the needle 89 is inserted into the sub tank 3, the sponge 33 in the sub tank 3 is compressed, and the pressure of the sponge 33 is released when the sponge 33 is extracted from the sub tank 3. Although the method has been described, the needle advancing / retreating mechanism 141 is used only for inserting / removing the needle 89 into / from the sub-tank 3, and the compression / decompression of the sponge 33 in the sub-tank 3 is performed by pressing the main tank 6 described above. The deformable member 3 is added to the member 62 and the sub tank 3.
5 may be used.

The structure of the sub tank 3 will be described with reference to FIG. The sub tank 3 has a sub tank chamber 30 therein.
An ink reservoir 31 is formed below the sub tank chamber 30. The ink reservoir 31 is provided with the nozzle 21 and an ink supply passage 22 for supplying ink to the nozzle 21, and the ink supply passage 22 is provided with a valve 32 as a passage opening / closing means. A sponge 33, which holds ink and is elastically deformable, is accommodated in the sub tank chamber 30 above the ink reservoir 31.

The sponge 33 is made of, for example, a foam material such as polyurethane, and the nozzle 2 of the print head 2 is used during non-printing.
It acts so that the ink does not leak from 1 and that air or bubbles do not enter into the ink in the sub tank chamber 30 when the print head 2 moves. A filter 36 is provided on the upper surface of the sponge 33. An opening / closing member 34 into which the tip of the needle body 81 can be inserted is formed on the upper portion of the sub tank 3.

On the side wall of the sub tank 3 on the main tank 6 side, a deforming member 35 is arranged so as to face the pressing member 62 protruding from the main tank 6. The deformable member 35 is made of polyurethane, silicone rubber, acrylic resin, PET (polyethylene terephthalate), or the like. With the print head 2 resting in the return position where the printing operation is not performed, the pressing member 6
2 deforms the sponge 33 by pressing it via the deformable member 35, and when the sub tank 3 is separated from the return position, the pressing force on the sponge 33 is released, and the negative pressure generated in the sponge 33 causes the sponge 33 to move. The ink is sucked into the inside of the print head 2 substantially uniformly, and the ink does not leak from the nozzle 21 of the print head 2.

FIG. 13 is a sectional view showing the construction and opening / closing operation of the valve 32 disposed in the ink supply passage 22.
The valve 32 is arranged with the flexible pipe portion 131 made of a soft material such as silicone rubber interposed in the ink supply path 22 connecting the ink reservoir 31 and the sub tank chamber 30, and the pipe portion 131 being sandwiched therebetween. The pipe pressing member 132 and the facing member 133, and the pressing lever 134 for pressing the pipe pressing member 132. The pressing lever 134 is biased to the right in the figure by a bias means (not shown), and the pipe pressing member 132 is biased upward in the figure by a bias means (not shown).

The valve 32 having the above-described structure is used for the pressing lever 13 during the printing operation shown in FIG.
4 is in the non-pressing position, the pipe pressing member 132 separates from the facing member 133 upward in the drawing to form a flow path in the pipe portion 131 (the valve 32 opens). On the other hand, when the pressing lever 134 is pressed to the left in the drawing as shown in FIG.
The pipe pressing member 132 is a hypotenuse 134a of the pressing lever 134.
Is guided to approach the opposing member 133 against the urging force of the bias means, and the flow path of the pipe portion 131 is blocked (the valve 32 is closed).

The valve 32 is opened during the printing operation of the print head 2, and when the print head 2 is in the returning position and ink is supplied through the needle 8, that is, the deformable member 35 and the sponge 33 are pressing members. It is closed when pressed at 62. Therefore, when positive pressure is generated in the sponge 33 due to the pressing of the pressing member 62, it is possible to prevent the ink from leaking from the nozzle 21. Further, since the slanted side 134a gently opens and closes, it is possible to reliably prevent ink leakage.

The position detecting means of the base 4 and the position detecting means of the needle 8 in the ink jet recording apparatus 200 will be described with reference to FIGS. 3 and 14. Base position detecting means 1
As shown in FIG. 3, reference numeral 00 denotes materials 101 and 102 having high reflectance such as aluminum attached to both ends of the bottom surface of the base 4 in the main scanning direction, and arranged at predetermined positions of the main body case 10. The photoelectric sensors 103 and 104 each include a light emitting unit and a light receiving unit, and highly accurately detect whether or not the base 4 is at a predetermined position such as a return position based on changes in the amount of light received by these light receiving units.

In the needle position detecting means 120, as shown in FIG. 14, the base 4 is in the return position, and when the ink is supplied, the tip of the needle 8 is securely placed in the sub tank 3 via the opening / closing member 34. It is composed of an optical detecting means for detecting whether or not it has been inserted into. The needles 8 and the opening / closing members 34 of the sub-tanks 3 are sequentially arranged for each color in the direction perpendicular to the traveling direction of the light beam emitted from the optical detecting means.

In the needle position detecting means 120, the light beam from the light source 121 composed of a semiconductor laser, an LED (Light Emitting Diode) or the like is converted into a beam expander 12.
The light is expanded in the horizontal direction, that is, in the direction perpendicular to the beam traveling direction by 2 and collimated into parallel light by the collimator lens 123, and then the needles 8 corresponding to the ink tanks of the respective colors are irradiated. The light not blocked by the needles 8 is collected by the condenser lens 124 and then received by the light receiving section 125 including a photodiode or the like.

Therefore, when the amount of light detected by the light receiving portion 125 in a state where all the needles 8 are surely inserted in the sub tank 3 is used as a reference value, any one of the needles 8 of each color is not inserted at all. In this case, a value higher than the reference value is detected, and if any one of the needles 8 stops midway and blocks the optical path, a value lower than the reference value is detected. In this way, it is possible to reliably detect whether or not all the needles 8 have been inserted into the sub tank 3 by one optical detecting means.

Next, the ink supply operation to the sub tank 3 will be described.
This will be described with reference to FIG. 15, which is a vertical sectional view of the sub tank 3. In FIG. 15, the liquid levels of the ink in the sub tank 3 are indicated by L0 to L4. The liquid levels L0 and L1 are constant, and the liquid levels L2 to L4 change depending on the ink usage condition and the ink injection condition.

First, when it is detected that the ink remaining amount in the sub tank 3 is small, the valve 32 is closed as shown in FIG. 15 (a). The remaining ink amount is detected, for example, by counting the number of dots ejected from the nozzle 21 with software and comparing this with a detection threshold value. When the print head 2 returns to the return position, FIG.
As shown in (b), the deformable member 35 is pressed by the pressing member 62 (the liquid surface L2 of the ink becomes L3), the opening / closing member 34 is then opened, and the tip of the needle body 81 is inserted.

Next, as shown in FIG. 15C, the amount of ink set according to the remaining amount of ink is supplied and the liquid surface of the ink becomes L4. The set ink amount is such that the liquid surface of the ink is higher than the tip of the needle body 81, and is set by rotating the pump motor 71 by a specified number of revolutions. Next, as shown in FIG. 15D, the pump motor 71 is reversely driven for a preset suction time. As a result, the excess ink not sucked into the sponge 33 is sucked through the needle body 81. The suction time is set so that this suction operation is continued even after the ink surface becomes L0.

In the above structure, the sponge 33 is once compressed to expel the air in the sponge 33, so that the ink can be evenly supplied into the restored sponge 33. The ink transfer means 7 ejects ink until a liquid level is formed above the tip of the needle body 81 inserted in the sub tank 3, and then until the liquid level of the ink drops to at least the tip of the needle 8. By sucking the ink, the liquid level of the ink is automatically set to the position of the tip of the needle 8, so that the ink amount in the sub tank 3 is kept constant with a simple configuration (the liquid level is always L0 Position). Further, even after the liquid surface of the ink reaches L0, the suction operation is continued to suck the ink remaining in the needle body 81, so that the ink remains in the needle body 81 and is left for a long time. Therefore, it is possible to prevent the needle body 81 from being clogged and resulting in clogging.

When the ink supply is completed, FIG.
As shown by, the needle body 81 is pulled out from the sub tank 3, and the opening / closing member 34 is closed. Next, when the print head 2 moves away from the return position for the printing operation, as shown in FIG.
As shown in (f), the deformable member 35 by the pressing member 62.
Is released (ink surface L0 becomes L1),
Then, the valve 32 is opened and ink is supplied to the nozzle 21.

In this way, since the ink is supplied and the excess ink is sucked by one needle 8, the structure of the ink transfer means 7 is simplified, and the liquid level detection of the sub tank 3 is complicated. Ink does not overflow from the sub-tank 3 even if various controls are not performed, and the process of always supplying a constant amount of ink can be efficiently performed with simple control. Further, when the ink in any one of the plurality of ink tanks of the sub tank 3 is low, it is possible to supply the ink to all the ink tanks and / or suck the excess ink, and as a result, It is not necessary to determine which color of ink has run out, and the detection unit and control unit are simplified.

The sub-tank 3 is provided with a sponge 33 which holds ink and is elastically deformable therein, and the main tank 6 has a pressing member 62 which can press the sponge 33 in the sub-tank 3. There is. When the sub tank 3 is engaged with the main tank 6, the sponge 33 is pressed by the pressing member 62 to raise the liquid level of the ink held inside the sponge 33, and when the sub tank 3 is separated from the main tank 6, The pressing by the pressing member 62 is released and restored. At this time, the ink is prevented from leaking from the nozzle 21 of the print head 2 due to the negative pressure generated inside the sponge 33. Also,
A valve 32 that is opened and closed according to the insertion and removal of the needle 8 with respect to the sub-tank 3 is provided. By opening the valve 32 when the operation is completed, it is possible to reliably prevent the ink from leaking from the nozzle 21.

Next, the ink transfer means connects at least two conduits whose tips are inserted into and removed from the auxiliary tank when the auxiliary tank is engaged with the main tank, and one end is connected to each base end of these conduits. And at least two elastically deformable tubes having the other end opened in the main tank, and squeezing these tubes in one direction by the rotor to discharge the ink of the main tank to the sub tank and simultaneously to cause excess of the sub tank. 1 shows a configuration including an ironing pump that sucks minute ink into a main tank.

FIG. 16 shows an ink jet recording apparatus 200.
19 is a perspective view showing the outer appearance of the main tank 6, the sub tank 3, and the ink transfer means 7 in FIG. 18, and FIG. 18 is a perspective view showing a part of the pump 70 by cutting away.

In FIG. 16, the ink transfer means 7 is 1
Two pumps 70 located above the main tank 6 of the chamber
(Ink discharge pump 70a and ink suction pump 70b) and a needle 8 as a conduit consisting of two needles, and a plurality of them are arranged as one set (an inkjet provided with ink tanks of 6 colors). 6 sets are arranged in the recording device 200). Needle 8
As shown in FIG. 17, the ink ejection needle 85 having the same diameter is used.
And the ink suction needle 86 are integrally connected, and the needle advancing / retreating mechanism 140 shown in FIG. 11 allows the ink ejecting needle 85 and the ink sucking needle 86 to integrally advance and retract in the holding member 82. Is configured.

The two pumps 70a and 70b are provided in each of the plurality of ink tanks, and when the sub tank 3 moves to the return position, the tip of the needle 8 enters the sub tank 3 and then the pump of the pump 70a. The motor 71a is driven to eject the ink contained in the main tank 6 from the ink ejection needle 85 of the needle 8 to the sub tank 3, and at the same time, the surplus ink in the sub tank 3 is sucked from the ink suction needle 86 of the needle 8. Then, it is returned to the main tank 6. A pulse motor, for example, is used as the pump motors 71a and 71b.

The pumps 70a and 70b shown in FIG.
The pump 70 shown in FIGS. 9 and 10 is used, but in this example, the rotor 73 is rotationally driven only in one direction by the pump motors 71a and 71b. Pump 7
0a, the input end P9ai of the tube 9a is connected to the main tank 6
The output end P9ao of this tube 9a opens at the bottom of the inside.
Is connected to the base end of the ink ejection needle 85. Further, in the pump 70b, the input end P9bi of the tube 9b is
Is connected to the base end of the ink suction needle 86, and the output end P9bo of this tube 9b is opened at the upper part in the main tank 6.

When the rotor 73 of the pump 70a is rotationally driven counterclockwise as indicated by the arrow in FIG. 18 by the rotation of the pump motor 71a, ink is sucked from the input end P9ai in the main tank 6 and the ink ejection needle 85 Ink is ejected from the tip of the. When the rotor 73 of the pump 70b is rotationally driven in the counterclockwise direction shown by the arrow in FIG. 18 by the rotation of the pump motor 71b, the excess ink in the sub tank 3 is discharged from the tip of the ink suction needle 86 in the sub tank 3. Can be sucked up and returned to the output end P9bo in the main tank 6.

By using two pumps and one needle 8 inserted into the sub tank 3 as described above,
Since the ink suction process by the ink suction needle 86 can be started in parallel with the start of the ink supply process by the ink ejection needle 85, the ink can be supplied in a short time. Further, since the ink ejection and the ink suction can be performed independently, the liquid level of the ink in the sub tank 3 can be precisely controlled. Since each of the needles 8 is composed of the ink ejection needle 85 and the ink suction needle 86 which are connected to each other as shown in FIG. The ejection needle 85 and the ink suction needle 86 are configured so as to integrally move forward and backward in the axial direction.

Next, the ink transfer means has a conduit whose tip is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and one end of which is connected to the base end of the conduit and the other end of which is the main tank. It consists of an elastically deformable tube opened inside and a squeezing pump that makes the tube unidirectional by the rotor. At least two squeezing pumps are used. An example will be described in which the ink in the main tank is discharged to the sub tank, and the other ironing pump draws the other tube in one direction by the rotor to suck the excess ink in the sub tank to the main tank.

FIG. 19 is a perspective view showing the outer appearance of the main tank 6, the sub tank 3, and the ink transfer means 7. In FIG. 19, an inkjet recording apparatus 200 includes a main tank 6 having a plurality of ink tanks whose interior is partitioned for each color of ink, a sub tank 3 having a plurality of ink tanks corresponding to each color of ink, and A plurality of needles 8 provided corresponding to the sub tank 3, and two pumps 70 (70a and 70b) arranged above the main tank 6.
Have. The main tank 6 is provided with the ink detection means 61.

The ink transfer means 7 includes two pumps 70 (70a and 70b) arranged above the main tank 6 which is an assembly of ink tanks of six colors of ink.
It consists of a plurality of needles 8 extending from each pump 70a and 70b.

Each of the pumps 70a and 70b is shown in FIG.
As shown in FIG. 0, six flexible tubes 91 to 9 are stacked one above the other along the arc-shaped wall surface 72 of the pump casing.
6 is pressed by each rotor 73 which is rotationally driven by each of the pump motors 71a and 71b.

In this example, the flexible tube 9 (91a, 92a, 93a, 94a, 9) arranged on the pump 70a is used.
5a / 96a) and the flexible tube 9 (91b / 92b / 93b / 94b / 95b) arranged on the pump 70b.
The input end and output end of 96b) are arranged as follows. That is, the input end P91ai of the tube 91a
Open at the bottom of the main tank 6, and the output end P91ao is connected to the ink ejection needle 85. Tube 92
Similarly, a to 96a have their input ends opened at the bottom of the corresponding main tank 6, and their output ends are connected to the ink ejection needles 85 of the respective needles 8. On the other hand, the input end P91bi of the tube 91b is connected to the ink suction needle 86, and the output end P91bo is connected to the main tank 6.
There is an opening at the top inside. Similarly, the tubes 92b to 96b have their input ends connected to the corresponding ink suction needles 86, and their output ends open at the top of the respective main tanks 6.

The ink ejection needle 85 to which the output end P91ao of the tube 91a is connected and the ink suction needle 86 to which the input end P91bi of the tube 91b is connected form one needle 8. Similarly,
Output ends P92ao-P96 of tubes 92a-96a
Each ink ejection needle 85 to which ao is connected
And the input ends P92bi to P of the tubes 92b to 96b.
Each ink suction needle 8 to which 96bi is connected
6 and 6 together form another five needles 8.
These tubes 91a to 96a, 91b to 96b are pressed by the rotor 73 which is rotationally driven by the pump motors 71a and 71b at the same time or with a time lag, thereby supplying 6 colors of ink and sucking excess ink.
Since it can be performed by the base pump motor, the number of parts is further reduced.

In this example, since the structure of the pump in the ink transfer means 7 is divided into the ink discharge pump 70a and the surplus ink suction pump 70b, as described above, the ink discharge and the ink discharge are performed. Suction can be performed independently, and by stopping the ink discharge pump 70a and stopping the drive of the ink suction pump 70b after a lapse of a predetermined time, the ink in the ink suction needle 86 is prevented from remaining. be able to. When the ink transfer means 7 is composed of the ink discharge pump 70a and the ink suction pump 70b, the ink discharge pump 70 is used.
The driving of the ink suction pump 70b may be started at the same time as the driving of the ink a is started, or the driving of the ink suction pump 70b may be started after a predetermined time (several seconds) delay from the driving start of the ink ejection pump 70a. .

Next, the ink transfer means connects at least two conduits whose tips are inserted into and removed from the auxiliary tank when the auxiliary tank is engaged with the main tank, and one end is connected to each base end of these conduits. And at least two elastically deformable tubes having the other end opened in the main tank, and squeezing these tubes in one direction by the rotor to discharge the ink of the main tank to the sub tank and simultaneously to cause excess of the sub tank. Configuration consisting of an ironing pump that sucks minute ink into the main tank,
That is, a configuration is shown in which one ironing pump is used to supply and suck ink of one color or a plurality of colors.

FIG. 21 is a perspective view showing the appearance of the main tank 6, the sub tank 3, and the ink transfer means 7. In FIG. 21, the ink transfer means 7 is composed of a pump 70 arranged above the main tank 6 and a needle 8 as a conduit consisting of two needle bodies, and a plurality of them are arranged as one set ( (6 sets are arranged in the ink jet recording apparatus 200 provided with ink tanks of 6 colors). As shown in FIG. 17, the needle 8 is configured by integrally connecting an ink ejection needle 85 and an ink suction needle 86 having the same diameter, and the needle advancing / retreating mechanism 140 shown in FIG.
Thus, the inside of the holding member 82 can be moved back and forth at the same time in the axial direction.

The pump 70 is provided for each of a plurality of colors of ink together with the main tank 6, and when the sub tank 3 returns to the return position, the tips of the needles 85 and 86 are inserted into the sub tank 3, and The ink stored in the main tank 6 is driven by the pump motor 71 so that the ink ejection needle 8
The ink is injected into the sub tank 3 via the nozzle 5 and at the same time, the excess ink in the sub tank 3 is sucked into the main tank 6 via the ink suction needle 86.

As shown in FIGS. 22 and 23, the pump 70 includes two flexible tubes 91 and 92 provided in parallel in the vertical direction along the arc-shaped wall surface 72 of the pump casing, and the pump motor 71. If an ironing pump that is pressed by a rotor 73 that is rotationally driven by is used and one end of each of the tubes 91 and 92 is an input end P91i / P92i and the other end of each is an output end P91o / P92o, the tube 91 The input end P91i is disposed near the bottom of the main tank 6, and the output end P91o is connected to the base end of the ink ejection needle 85. The input end P92i of the tube 92 is connected to the base end of the ink suction needle 86, and the output end P92o is arranged in the upper portion of the main tank 6.

When the rotor 73 rotates in the direction of the arrow in FIG. 23 due to the rotational drive of the pump motor 71, the input end P91i
The ink in the main tank 6 is sucked from the ink, and the ink is ejected from the tip of the ink ejection needle 85. At the same time, the excess ink in the sub tank 3 can be sucked up from the tip of the ink suction needle 86 and returned to the main tank 6. With such a configuration, it is possible to eject ink and suck excess ink at the same time.
It is possible to supply the ink in a short time without causing the ink to overflow from the sub tank 3 without performing complicated control such as liquid level detection.

Next, another configuration example of the ink transfer means 7 will be described below with reference to the drawings. FIG. 24 shows the main tank 6,
3 is a perspective view showing the external appearance of the ink transfer unit 7 including the sub tank 3. FIG. In this embodiment, the ink transfer means 7 includes a pump 70 arranged above the plurality of main tanks 6, and a pump 7.
It is composed of a plurality of needles 8 extending from 0 toward each of the plurality of sub-tanks 3. That is, one pump 70 is used for ink of four colors and six colors. Note that FIG. 24 and FIG.
5 and FIG. 26, in order to simplify the description, a case of supporting two color inks (main tank 6: ink tank 6
a.6b, sub-tank 3: ink tanks 3a, 3b, needles 8: 8a, 8b).

As shown in FIGS. 25 and 26, the pump 70 includes four flexible tubes 101, two of which are provided vertically in parallel along the arc-shaped wall surface 72 of the pump casing.
A squeezing pump that presses 102, 103, and 104 with a rotor 73 that is rotationally driven by a pump motor 71 is used. At both ends of the wall surface 72 of the pump 70, tube holes 74 and 75 are formed to allow four tubes to pass therethrough. Lower tube 101.1 inside pump 70
02 and the upper tubes 103 and 104 penetrate one tube hole 74, and the two tubes form a set to form a rotor 73.
After branching to the left and right around the axis of (1) and passing through approximately the half circumference of the wall surface 72 along the inner surface of the wall surface 72, they are assembled and penetrate the other tube hole 75.

Tubes 101, 102, 103, 104
P101i / P102i / P10
3i · P104i, and the output end of these tubes is P
In the case of 101o / P102o / P103o / P104o, these connections or arrangements are as follows.
The input end P101i of the tube 101 is connected to the base end of the ink suction needle 86 of the needle 8a, and the output end P10i.
1o is arranged in the upper part of the main tank 6a. Tube 1
The input end P102i of 02 is arranged near the bottom of the main tank 6a, and the output end P102o is connected to the base end of the ink ejection needle 85 of the needle 8a. The input end P103i of the tube 103 is connected to the base end of the ink suction needle 86 of the needle 8b, and the output end P103o is connected to the main tank 6.
It is located at the top in b. Input end P1 of tube 104
04i is arranged at the bottom of the main tank 6b and has an output end P1.
04o is connected to the base end of the ink ejection needle 85 of the needle 8b.

When the rotor 73 rotates in the direction of the arrow in FIG. 26 by the rotational drive of the pump motor 71, the input end P10
Ink in each main tank 6 is sucked from 2i and the input end P104i, and ink is ejected into each sub tank 3 from the tip of each ink ejection needle 85. At the same time, excess ink in each sub tank 3 can be sucked up from the tip of each ink suction needle 86 and returned to each main tank 6. In this case, as shown in FIG. 15, when ink is supplied to the entire area of the pressed sponge 33, excess ink not sucked into the sponge 33 starts to accumulate on the filter 36. However, since the excess ink is immediately sucked by the ink suction needle 86, the liquid surface of the ink in the sub tank 3 is maintained at the position of the liquid surface L0. 26 shows the pump 70 having four rotors 73, this mode may be applied to the pump 70 shown in FIG. 9, FIG. 18, or FIG. Absent.

With such a configuration, it is possible to discharge ink from a plurality of ink tanks and suck excess ink at the same time with one pump 70, so that complicated control such as liquid level detection of the sub tank 3 is performed. Is simplified, and ink can be supplied in a short time without causing the ink to overflow from the sub tank 3.

FIG. 27 shows, as an example of the ink transfer means 7, a structure in which a flow passage cross-sectional area adjusting means is provided between the pump 70 and the ink discharge needle 86. Channel cross-sectional area adjusting means 11
0 is a bellows 1 in the shape of a bottomed container having a stretchable portion 111a.
11, a tube body 112 penetrating the upper wall surface of the bellows 111, and a bellows displacement means for displacing the bellows 111. The bellows displacement means supports the bottom part of the bellows 111 at the upper part and the rack gear 1 carved at the lower part.
It comprises a support member 114 having 13 and a pinion gear 115 for driving the rack gear 113. The rotation of the pinion gear 115 is rotated by the rack gear 113 by a drive system (not shown).
Is transmitted to the support member 114, the support member 114 moves up and down, and
The flow passage cross-sectional area in the bellows 111 can be changed by expanding and contracting 1a.

The flow passage cross-sectional area change amount (expansion / contraction amount) of the bellows 111 is formed to be larger than the volume of the flow passage from the outlet 11b of the bellows 111 to the tip of the ink discharge needle 85 / ink suction needle 86. Therefore, by changing the flow passage cross-sectional area in the bellows 111, it is possible to prevent the ink from remaining in the ink ejection needle 85 and the ink suction needle 86. Channel cross-sectional area adjusting means 11
0 is the two pumps 70 (7 shown in FIGS. 16 and 19).
0a and 70b) is used to supply and suck one color ink or a plurality of inks, it is provided between the ink discharge pump 70a and the ink discharge needle 85. As shown in FIGS. 21 and 24, when supplying and sucking one color ink or a plurality of inks using one pump 70, the pump 70, the ink ejection needle 85, and the ink suction It is arranged between the needle 86 and the needle 86. In the mode using the two pumps 70 (70a and 70b), instead of providing the flow passage cross-sectional area adjusting means 110 between the ink discharge pump 70a and the ink discharge needle 85, as described in FIG. The pump motor 71a may be rotated in the reverse direction so that the ink remaining in the ink ejection needle 85 is returned to the main tank 6. The support member 114 is lifted and lowered when
4 is fixed to a fixed member via an elastic member such as a spring, an eccentric cam is rotated between the fixed member and the support member 114, or a tapered spacer is inserted between the support member 114 and the fixed member. It can also be performed by other methods such as

The ink supply operation of the ink transfer means 7 having the above-mentioned flow passage cross-sectional area adjusting means 110 will be described with reference to the flowchart of FIG. The following control is performed based on a command from a control unit (not shown). First, in step S1, the photoelectric sensor 103.10 of FIG.
When the position of the base 4 is detected by the controller 4, the step S
2, it is determined whether or not the base 4 is at a predetermined position such as a return position. If the determination is NO, step S
Returning to step 1, when the base 4 reaches the return position, step S3
Move to. Ink supply valve 3 in step S3
When 2 is closed, in step S4, the opening / closing member 34 is opened to move the needle 8 forward, and the pressing member 62 presses the deformable member 35 to compress the sponge 33 in the sub tank 3.

In step S5, the optical detecting means 120 shown in FIG. 14 detects from the amount of transmitted light whether or not the tip of the needle 8 is securely inserted into the sub tank 3. Next, in step S6, it is determined whether or not the detection result is equal to the reference value when all the needles 8 are surely inserted in the sub tank 3. If the detection result in step S6 is not equal to the reference value, the process proceeds to step S13. In step S13, step S
At 4, it is determined whether or not a predetermined time has elapsed since the insertion of the needle 8 was started. If this judgment is NO,
It is determined that the needle 8 is in the displacement driving step S5.
Return to. On the other hand, if this determination is YES, it is determined that there is some kind of failure, and in step S14 a display is output indicating that inspection of the ink transfer means 7, the base 4, the optical detection means 120, etc. is required, and the operation is performed. finish.

When it is determined that the detection result in step S6 is equal to the reference value, it is determined that the needle 8 has been reliably inserted into the sub tank 3, and step S7
In, the bellows 111 is compressed and the ink stored in the bellows 111 at the time of the previous supply is ejected. In step S8, the pump 70 is driven to supply the ink and suck the surplus ink as described above.

In step S9, the pump 70 is stopped, the bellows 111 is further extended, and the ink remaining in the ink ejection needle 85 and the ink suction needle 86 is collected in the bellows 111. In step S10, the needle 8 is retracted and pulled out from the sub tank 3, and the pressing member 62 is driven to release the compression of the sponge 33. In step S11, the above-mentioned step S10
The process waits for a predetermined time until the process of (1) is completed, and then the valve 32 is opened in step S12 to complete the operation.

As described above, by controlling the driving of the bellows 111 in synchronization with the movement of the base 4 provided with the sub tank 3, it is possible to easily prevent a malfunction due to a deviation of the timing of ink supply. In addition, after the ink discharge needle 85 is completely inserted into the sub-tank 3 at the time of discharging the ink, the bellows 11 is waited for after the detection result.
By compressing 1 and discharging the ink sucked from the ink discharge needle 85 and / or the ink suction needle 86 at the time of the previous ink supply, there is a malfunction such that the ink is discharged at a place other than the sub tank 3. To be prevented. By the flow path cross-sectional area adjusting means 110, the ink ejection needle 85 and the ink suction needle 8 due to the remaining ink
The clogging of 6 can be reliably prevented with a simple mechanism.

29 to 33 show another embodiment of the needle 8 of the ink transfer means 7 of the present invention other than the above. The proximal end of each needle 8 is connected to the input end or the output end of the flexible tube 9 arranged in the pump 70, and functions as an ink ejection needle 85 and an ink suction needle 86. One or more flexible tubes 9 are appropriately arranged along the arc-shaped wall surface 72 of the pump casing.

As shown in FIG. 29, the needle 8 includes two ink ejection needles 85 and an ink ejection needle 85.
And two ink suction needles 86 having the same diameter as the above. In this way, by configuring the needle 8 with the plurality of ink ejection needles 85 and the ink suction needle 86, it is possible to shorten the time for supplying a fixed amount of ink to the sub tank 3.

In FIG. 30, the needle 8 is composed of one ink ejection needle 85 and two ink suction needles 86 having the same diameter as the ink ejection needle 85. With this configuration, the ink ejection needle 8
If the conductance of 5 is Cin and the conductance of the ink suction needle 86 is Cout, then Cout>
It becomes Cin, and the conductance Cout on the ink suction needle 86 side can be improved. Therefore,
The amount of ink sucked by the ink suction needle 86 is equal to or larger than the amount of ink supplied by the ink discharge needle 85, and ink can be supplied so that the ink amount in the sub ink tank 3 is always constant without leaving excess ink. it can.

Similarly, as shown in FIG. 31, the conductance of the ink ejection needle 85 is set to Cin by forming the flow passage total sectional area ΣSout of the ink suction needle 86 larger than the flow passage total sectional area ΣSin of the ink ejection needle 85. When Cout is the conductance of the ink suction needle 86, Cout> Cin holds,
The conductance Cout of the ink suction needle 86 can be improved. By setting such a flow path, the ink suction flow rate by the ink suction needle 86 becomes larger than the ink supply flow rate by the ink ejection needle 85, and the ink amount in the sub tank 3 is always constant without leaving excess ink. Ink can be supplied as described above.

In FIG. 32, one thin tube (tubular body) is bent and an opening 87 is formed in the vicinity of the bent portion. One of the thin tubes is used as an ink discharge needle 85a and the other is used as an ink suction needle 86a. Is. The conductance determined by the formation position and diameter of the opening 87 is C
When set to op, it is configured to satisfy Cop> Cout ≧ Cin.

Further, as shown in FIG. 33, the opening 87 may be formed near the ink suction needle 86. By thus bending the single thin tube to configure the needle 8, it is possible to always supply a fixed amount of ink without leaving an excess amount of ink. Further, the structure of the needle 8 is simplified, and the pressing area when the sponge 33 in the sub tank 3 is pressed by the tip of the needle 8 can be enlarged.

[Second Embodiment] FIG. 34 shows a second embodiment of the present invention.
FIG. 3 is a perspective view showing an overall configuration of an inkjet printer as an inkjet recording apparatus according to the embodiment of the present invention. The inkjet recording apparatus 400 includes a print head 2 that ejects ink droplets onto a recording medium, a tank 13 that stores ink supplied to the print head 2, and a base 4 that mounts the print head 2 and the tank 13. A print head moving means 5 that mounts the print head 2 and the tank 13 to move the print head 2 between a print position and a return position, and a reaction force generated when the print head 2 reciprocates in the main scanning direction is absorbed. The reaction force absorption means 15 and the main body case 10 that supports them are mainly configured.

The base 4 mounts the tank 13 and the print head 2 disposed below the tank 13 and extends the print head with respect to the recording medium in the main scanning direction (the arrow X direction in the drawing). It is slidably supported by a feed shaft 51 as a reference numeral 5 and a positioning means 54 which keeps the distance between the print head 2 and the recording medium constant. Further base 4
Is driven to be displaced in the main scanning direction with the feed shaft 51 as a guide by a timing belt 53 which is stretched in parallel with the feed shaft 51 and driven by a driving means 52. The feed shaft 51, the positioning means 54, and the driving means 52 are supported by the main body case 10. The reaction force absorbing means 15 is arranged behind the feed shaft 51.

The reaction force absorbing means 15 comprises the feed shaft 5
The feed shaft 5 supported by the main body case 10 behind
5, a counter weight 56 as a counter member slidably supported using the feed shaft 55 as a guide, a positioning means 59 for positioning the counter weight 56 in the vertical direction, and a tension member extending in parallel with the feed shaft 55. The timing belt 58 is driven by the driving means 57. As shown in FIG. 35, the counter weights 56 are arranged apart from each other so as not to contact the base 4,
Based on the detection result of the ink remaining amount detecting means which will be described later, the displacement is driven in parallel with the print head 2 in the main scanning direction (the arrow X direction in the drawing). The counter weight 56 is the base 4.
In contrast, the drive is performed so that the phases are opposite to each other, and the inertial force of the base 4 is canceled to suppress the vibration generated in the inkjet recording apparatus 400.

In FIG. 34, the recording medium is fed from the paper feeding section 11 in the sub-scanning direction (direction of arrow Y in the figure), and the base 4
Moves in the main scanning direction (direction of arrow X), and an image is formed on the recording medium by the mounted print head 2. The recording medium is provided in the paper feed unit 11, is fed one by one by a paper feed roller (not shown), and is supplied below the print head 2 by a conveyance roller (recording medium conveyance means) 182. The recording medium on which image formation has been completed by the print head 2 is ejected to the paper ejection unit 12.

The base 4 is moved to a return position where the print head 2 is stopped near one end of the feed shaft 51 when the print head 2 is not performing a printing operation. As the print head 2 and the tank 13, those having the same form as in FIG. 4 are used. In this case, since the main tank 6 is not provided, the deformable member 35 is not provided.
The print head 2 is driven in a direction (Y direction in FIG. 4) orthogonal to the row of nozzles 21. In addition, the print head 2
As shown in FIG. 34, is provided with an ink remaining amount detecting means 16 for detecting the remaining amount of ink. As the ink remaining amount detecting means 16, a method of recognizing the ink remaining amount by counting the number of dots of ink ejected from the print head 2 at the time of printing by software, an electrode is provided in each color ink tank of the tank 13, and at a constant time interval. It is possible to apply a method in which an electric current is passed to see a change in resistance value between electrodes, an optical detection method, a weight detection method, and the like.

The remaining ink amount detecting means 16 based on the optical detecting method will be described with reference to FIG. The optical detection method is a method in which the presence or absence of ink is detected from the outside of the tank 13 by a reflection type optical sensor by utilizing the difference in reflectance depending on the remaining amount of ink in the tank 13. For example, the light from the light source 171 composed of an LED is turned on / off for each ink tank in synchronization with the moving speed of the base 4, and is applied to the tank 13 via the half mirror 172 and the lens 173. The light reflected on the surface of the tank 13 is reflected by the lens 173.
It is detected by the light receiving element 174 via the half mirror 172. If there is ink in the tank 13, the tank 13
The reference light amount is detected by the light receiving element 174 due to the reflected light from itself and the ink. However, when the remaining amount of ink is small, only the tank 13 is reflected light, so the light amount detected by the light receiving element 174 decreases. Therefore, it is possible to recognize the remaining amount of ink in the tank 13 by using the detected difference in the amount of light. As an optical detection method, a reflection type photo interrupter in which a light source and a light receiving element are arranged adjacent to each other may be used. In addition, by arranging a plurality of electrodes used in such an optical detection method and the above-described method of observing the change in the resistance value between the electrodes in the height direction of the tank 13,
The remaining ink level can be detected from the position of the signal indicating the presence of ink.

Next, the ink remaining amount detecting means 16 based on the above weight detecting method will be described. In this case, the ink remaining amount detecting means 16 is provided not in the print head 2 but in the main body case 10 at the return position of the print head 2. This method includes, for example, the method disclosed in Japanese Patent Application Laid-Open No. 9-136424, and when the sensor unit for detecting the weight of the base 4 and the base 4 arrives at a predetermined position (return position). In addition, the weight of the base 4 is measured by the lever portion that transmits the weight of the base 4 to the sensor portion and the sensor portion that detects the weight. Specifically, as shown in FIG. 37, an arm 10a extending from the main body case 10 in a substantially L-shape, and a lever 162 rotatably attached to a rotation center 161 set on the upper portion of the arm 10a. And a protrusion 163 which is supported by the base 4 and slides on the lever 162, and an arm 10a.
It is mainly composed of a weight sensor 164 disposed above and for weight detection, which is pressed by a lever 162.

As shown in FIG. 38, the weight sensor 164 includes a case 165 and a coil spring 166.
And a convex portion 167a and a flat plate-shaped base portion 167b,
The mover 167 biased by the coil spring 166 so that the tip of the protrusion 167a projects from the hole 165a of the case 165, the first electrode 168, and the second electrode 16
It consists of 9. The first electrode 168 is arranged on the main surface of the base portion 167b from which the convex portion 167a projects, and the second electrode 169 is arranged on the top surface inside the case 165 adjacent to the hole portion 165a. Both electrodes 168 and 169 are constantly in contact with each other by the urging force of the coil spring 166 to which a predetermined set load is applied. When the two electrodes 168 and 169 contact each other to maintain the ON state and the measured weight is larger than the set load, both electrodes 168.1
69 is separated and turned off.

When the weight of the base 4 changes, the lever 162
The position of the protrusion 163 on the upper side is changed and the weight sensor 16 is changed.
The position at which the OFF signal is obtained from 4 changes. That is, the weight of the base 4 is T, the set load of the coil spring 166 is Ts, the distance between the convex portion 167a that is the detection portion of the weight sensor 164 and the rotation center 161 of the lever 162 is L ′, and the protrusion on the lever 162 is. When the contact position of 163 is L, T = Ts × L ′ / L (1), and the weight of the base 4 can be obtained if the value of L is known. The contact position L of the protrusion 163 on the lever 162 is
It can be obtained by a known control technique based on the output of a high-precision pulse motor or encoder that controls the position or speed of the base 4.

Next, a method of suppressing the vibration generated in the ink jet recording apparatus 400 by the reaction force absorbing means 15 based on the result detected by the ink remaining amount detecting means 16 will be described. Here, a case where a weight detection method is used as the remaining ink amount detection means 16 will be described. FIG. 39 shows an essential part of the reaction force absorbing means 15.
As described above, the counter weight 56 is driven by the driving means 57 so that the phase thereof is opposite to that of the base 4. When the amount of ink remaining in the tank 13 mounted on the base 4 changes, the inertial force generated in the inkjet recording apparatus 400 during acceleration / deceleration changes. Therefore, by driving the counterweight 56 in the opposite phase, It cancels the force and suppresses vibration.

When the total weight of the base 4 detected by the remaining ink amount detecting means 16 is Mc, the acceleration of the base 4 is αc, the weight of the counterweight 56 is Mw, and the acceleration of the counterweight 56 is αw, the driving means Reference numeral 57 drives and controls the counterweight 56 so that a force of αw × Mw = −Mc × αc (2) is generated. Since the weight Mw of the counter weight 56 is known and the base 4 is controlled so as to have a constant acceleration, based on the measured weight Mc of the base 4, the calculation means described later causes The calculation of Expression (2) is performed.

Another embodiment of the reaction force absorbing means 15 is shown in FIG. In this example, two eccentric rotors (a pair of eccentric members) 171 and 172 having the same shape are used. A belt 58 is stretched between one of the eccentric rotors 171 and the driving means 57, and the other of the eccentric rotors 172 is arranged between them and also serves to give tension to the belt 58. Two eccentric rotors 171, 172
Are simultaneously driven by the drive means 57, and when the belt 58 rotates in the direction of arrow A in the figure, the eccentric rotor 171 rotates counterclockwise and the eccentric rotor 172 rotates clockwise. The principle of canceling the inertial force of the base 4 by the eccentric rotors 171, 172 will be described with reference to FIG. The two eccentric rotors 171 and 172 have the same phase in the initial state and are rotationally driven in the opposite directions as described above.
When the weight of the two eccentric rotors 171, 172 is m and the distance from the center of rotation to the center of gravity G is r, the inertial force Fx in the x direction (main scanning direction) generated by the rotation and the y direction (sub scanning direction). The inertial force Fy of) is Fx = mrω ² cos θ (3) Fy = mrω ² sin θ (4) Here, ω indicates the angular acceleration, and θ indicates the rotation angle.

Since the two eccentric rotors 171 and 172 are rotationally driven in opposite phases, the two eccentric rotors 171 and 172
The inertial force due to 172 is Fx = mrω ² cos θ + mrω ² cos (−θ) = 2mrω ² cosθ (5) Fy = mrω ² sin θ + mrω ² sin (−θ) = 0 (6) Therefore, the total weight of the base 4 is Mc and the acceleration is αc.
Then, the rotors 171 and 172 are driven by the driving means 57 so that Mc × αc + 2m rω ² cos θ = 0 (7) is satisfied.
The drive is controlled by, and the generation of vibration is suppressed. In this case as well, similar to the above, the two eccentric rotors 171, 172
Since the weight m, the distance r from the center of rotation to the center of gravity G, and the acceleration αc of the base 4 are known, the drive means 57 may be controlled based on the weight Mc of the base 4 obtained by the weight detection method. . In the above configuration, the reaction force absorption means 1
The eccentric rotor 171.1 does not have to drive the counterweight 56 as 5 in the direction opposite to the scanning direction of the print head 2.
By rotating 72 in opposite directions, the inertial force of the base 4 can be canceled and the vibration generated in the inkjet recording apparatus 400 can be suppressed.

Next, an example of the structure of the control section 180 for driving the reaction force absorbing means 15 based on the ink remaining amount detecting means 16 will be described below with reference to the drawings. 42 is a block diagram of the control unit 180, and FIG. 43 is a flowchart showing the operation of the control unit 180. As the remaining ink amount detecting means 16, in the method of observing the change in resistance value between the electrodes and the optical detecting method, a plurality of electrodes or light sources / light receiving elements are arranged in the height direction of the tank 13.

As shown in FIG. 42, the control section 180 includes a drive means 52 for the print head 2, a drive means 57 for the reaction force absorbing means 15, a computing means 183, and an ink remaining amount detecting means 1.
6, the storage unit 181, and the recording medium conveying unit 182 are connected to the respective input / output units. The storage means 181
Stores data (calibration curve) for driving the reaction force absorbing means 15 so that the ink jet recording apparatus 400 does not vibrate, and detection data for the remaining ink amount detecting means 16.

The operation of the control unit 180 will be described with reference to FIG. First, in step S21, the state of the print head 2, that is, the remaining amount of ink is detected by the remaining ink amount detecting means 16. Next, in step S22, the detection result of the remaining ink amount and the reference value are compared. This reference value is the minimum level of ink in the tank 13. This minimum level is detected from the lowest position of the electrodes and the light source / light receiving element arranged in the height direction of the tank 13 in the method of observing the resistance change between the electrodes and the optical detection method. Whether there is a signal or not. In the method of counting the number of dots ejected during printing with software,
It is whether or not the total number of dots exceeds the reference value, and in the weight detection method, whether or not the measured weight of the base 4 is equal to or more than the reference value.

When it is determined in step S22 that the detection result is equal to or greater than the reference value, that is, the ink is still sufficient, the storage means 181 is determined based on the detection result (remaining ink level) in step S23. The calibration value is read from. In this case, it is preferable to use a lookup table in which the input signal and the output signal are stored in association with each other as the storage unit 181. next,
In step S24, the above-mentioned calibration value is input to the driving means 57, and the counter weight 5 as the reaction force absorbing means 15 is inputted.
6 is activated.

On the other hand, in step S22, when it is determined that the detection result is less than the reference value, the ink remaining amount is low, or the ink remaining amount detecting means 16
Is not operating normally, step S
At 25, the print head 2 or the remaining ink amount detecting means 1
The fact that 6 is inspected is displayed on a display unit (not shown) of the ink jet recording apparatus 400, for example, a liquid crystal display, or an alarm is issued, and a series of processing is ended.

When the weight detecting method is used as the ink remaining amount detecting means 16, as described above, the detected base 4
Alternatively, the reaction force absorbing means 15 may be driven based on the result of the calculation, and similarly to the above case, the detected weight of the base 4 and the calibration value of the driving means 57 are stored in the storage means. Alternatively, the counter weight 56 may be stored in 181 and the calibration value corresponding to the detection result may be read out to drive and control the counter weight 56.

Although the case where the reaction force absorbing means 15 is arranged with respect to the print head 2 has been described above, FIG.
A vibration detecting unit may be arranged in the main body case 10 instead of the remaining ink amount detecting unit 16 shown in (3) (described in the third embodiment below) to directly detect the vibration generated in the inkjet recording apparatus 400. Also in this case, the vibration generated in the inkjet recording apparatus 400 and the calibration value of the driving unit 57 are stored in the storage unit 181 in advance, and are similarly controlled based on the flowchart shown in FIG. In this case,
The reference value in step S22 is the minimum value of the vibration observed when the remaining amount of ink is small. In addition, as the above-mentioned vibration detection means, a strain gage method that applies the principle that a strain is generated when a force is applied to a strain gage and a change in resistance is applied, a spring mass system is used, and a force proportional to an external force (acceleration) is used. Is generated in the piezoelectric element and the electric charge generated in the piezoelectric element is measured, or a magnetostrictive element,
A known acceleration converter such as a capacitance type can be used.

As the vibration detecting means, a method of detecting the current of the driving means 52 for driving the base 4 (print head 2) may be used. In this case, the base 4 is controlled so that the acceleration is always constant as described above, and when the weight of the base 4 changes, the torque of the driving means 52, that is, the current value changes. The drive means 5 detects this change.
2 may be driven. The control method is the same as the above, and therefore will be omitted.

FIG. 44 shows still another embodiment of the reaction force absorbing means 15. In this example, the inertial force due to the bases 4 is not canceled by a mere weight body, but the sub-tanks 3 mounted on the two bases 4 are used to move in opposite directions so as to have opposite phases. Is configured. Figure 4
4, feed shafts 51a and 51b parallel to each other
The sub-tank 3 is mounted on the bases 4a and 4b slidably supported by the
a, 3b are mounted, and the sub-tanks 3a, 3b are connected to the main tanks 6a, 6b via the respective tubes ta, tb.
connected to b. The main tanks 6a and 6b are, as shown in the first embodiment, the return positions of the sub tanks 3a and 3b,
That is, it is arranged on the side surface of the inkjet recording apparatus 400. The main tanks 6a and 6b may be arranged on the same side surface of the ink jet recording apparatus 400 or so as to face each other, but the latter form is preferable in the sense of effectively utilizing the space on the side surface. Each base 4a ・ 4b
By means of the corresponding driving means 52a and 52b,
It moves along the feed shafts 51a and 51b, respectively. As the driving means 52a and 52b, those having the same configuration as shown in FIG. 34 are used. The sub-tanks 3a and 3b are provided with the above-mentioned remaining ink amount detecting means 16 (not shown), the amount of ink used is constantly detected, and the amount corresponding to the reduced amount is supplied to the main tank by an ink supply pump (not shown). 6a ・ 6
It is supplied from b to the sub tanks 3a and 3b.

In this example, the weights of the bases 4a and 4b are always controlled to be the same, and the inertial forces of the two are canceled by driving them in opposite directions so that they are in opposite phases. Inkjet recording device 4
It is possible to suppress the vibration generated in 00. in this case,
As the remaining ink amount detecting means 16, a method of observing a change in resistance value between electrodes, an optical detecting method, or a method of counting the number of dots ejected at the time of printing by software is used, and the sub tank 3a. The remaining amount of ink in 3b is detected.

A method of controlling the reaction force absorbing means 15 in the case of using the above configuration will be described with reference to the flowchart of FIG. First, when printing by the print head 2 is started, the state of the bases 4a and 4b, that is, the remaining amount of ink in the sub tanks 3a and 3b is detected by the above-described remaining ink amount detecting means 16 in step S31. Next, in step S32, it is determined whether the amount of ink in the main tanks 6a and 6b is equal to or greater than the reference value. The reference value mentioned here is the minimum level of the remaining amount of ink in the main tanks 6a and 6b. As a method of detecting the ink remaining amount in the main tanks 6a and 6b, the above-described method of observing the change in the resistance value between the electrodes or the optical detection method is used, and whether or not the ink is above the minimum level is determined for each ink tank. It should be detected.

If there is sufficient ink in the main tanks 6a and 6b, ink is replenished from the main tanks 6a and 6b so that the amount of ink in the sub tanks 3a and 3b becomes a predetermined amount (step S33). As the ink remaining amount detecting means 16 of the sub tanks 3a and 3b, it is preferable to use a method of counting the number of dots of ejected ink by software. in this case,
The counted value is compared with the counted value which is slightly smaller than the ink discharge amount which may cause vibration in the inkjet recording apparatus 400, and when this counted value is reached in one of the sub tanks, the sub tanks 3a and 3b In each
An amount of ink corresponding to the amount of ink discharged at that time is replenished for each color. When a method of observing a change in resistance value between electrodes or an optical detection method is used, it is possible to detect a change from a position where ink is sufficiently filled to a level slightly higher than the remaining ink amount where vibration may occur in the inkjet recording apparatus 400. If a plurality of detection methods described above are provided and even one color has reached the reference value, it is sufficient to replenish the ink in an amount commensurate with the ink reduction amount at that time. Then, in step S34, the reaction force absorbing means 15, that is, the bases 4a and 4b are driven by the driving means 52a.
It is driven by a predetermined current value by 52b.

On the other hand, in step S32, the main tanks 6a and 6a
When it is determined that the remaining amount of ink in b is small, all the driving of the inkjet recording device 400 is stopped and a message to that effect is displayed in step S35.
Replacing the main tanks 6a and 6b (or the main tanks 6a and 6b)
Ink is replenished). When the replacement of the main tanks 6a and 6b or the replenishment of ink is completed, step S3
Go to 3. In step S32, the main tanks 6a and 6b
When it is determined that the remaining amount of ink in the inside is small, the positions of the bases 4a and 4b and print information at that time are stored in the storage unit 181, and the main tanks 6a and 6b are replaced or ink is replenished. When this is detected, printing is continued again based on the above information.

In the above structure, since the sub-tanks 3a and 3b are used as counter members and the weights of the sub-tanks 3a and 3b can be made the same by replenishing the ink, it is not necessary to separately provide the counter weight 56 and By storing a large amount of ink in the sub-tanks 3a and 3b to reduce the number of times of ink replenishment, and by providing two print heads 2, it is possible to shorten the printing time. The sub-tanks 3a and 3b
And the main tanks 6a and 6b are tubes ta and tb, respectively.
Instead of connecting with the main tank 6a and 6b, the main tanks 6a and 6b are provided at the ends of the bases 4a and 4b in the scanning direction shown in the first embodiment, and the main tank 6 is driven by the pump 70.
Ink transfer means 7a and 7b for supplying ink from the a and 6b to the sub tanks 3a and 3b may be used. In this case, if the number of ejected ink dots counted by the software in any of the sub-tanks 3a and 3b reaches a count value slightly smaller than the ink ejection amount that can cause vibrations in the inkjet recording apparatus 400, the above-described operation is performed. Ink is supplied to each ink tank by the method, and the sub tank 3
a and 3b always hold the same amount of ink, that is,
The weights of the bases 4a and 4b are controlled so that they are always the same.

As described above, in this embodiment, the reaction force absorbing means 15 is driven in accordance with the detection result of the remaining ink amount detecting means 16 to print without being affected by the ink amount in the ink tank. The reaction force resulting from the driving of the head 2 can be reliably absorbed. In addition, in a configuration in which a plurality of main tanks and sub-tanks are provided and ink is supplied from the main tank to the sub-tank, the drive of the sub-tank (base) should be controlled with the same amount of ink held in the sub-tank. As a result, the reaction force can be absorbed with high accuracy.

[Third Embodiment] FIG. 46 shows a third embodiment of the present invention.
FIG. 3 is a perspective view showing an overall configuration of an inkjet printer as an inkjet recording apparatus according to the embodiment of the present invention. The inkjet recording apparatus 600 includes a print head 2 that ejects ink droplets onto a recording medium, a tank 13 that stores ink supplied to the print head 2, and a base 4 that mounts the print head 2 and the tank 13. A print head moving means 5 for mounting the print head 2 and the tank 13 to move the print head 2 between a print position and a return position, a vibration detecting means 18 for detecting a vibration of the print head 2, and a main body for supporting these. The case 10 is mainly configured.

The base 4 mounts the tank 13 and the print head 2 arranged below the tank 13 and extends the print head with respect to the recording medium in the main scanning direction (the arrow X direction in the drawing). It is slidably supported by a feed shaft 51 as a reference numeral 5 and a positioning means 54 which keeps the distance between the print head 2 and the recording medium constant. Further base 4
Is driven to be displaced in the main scanning direction with the feed shaft 51 as a guide by a timing belt 53 which is stretched in parallel with the feed shaft 51 and driven by a driving means 52. The feed shaft 51, the positioning means 54, and the driving means 52 are supported by the main body case 10. A vibration detecting means 18 described later is disposed below the base 4, and horizontal detecting means 17 described below is disposed at each of four lower corners of the main body case 10.

In FIG. 46, the recording medium is fed from the paper feeding section 11 in the sub-scanning direction (direction of arrow Y in the figure), and the base 4
Moves in the main scanning direction (direction of arrow X), and an image is formed on the recording medium by the mounted print head 2. The recording medium is provided in the paper feed unit 11, is fed one by one by a paper feed roller (not shown), and is supplied below the print head 2 by a conveyance roller (recording medium conveyance means) 182. The recording medium on which image formation has been completed by the print head 2 is ejected to the paper ejection unit 12.

Vibration detecting means 18 and horizontal detecting means 17
An example of the configuration of the control unit 230 that controls the entire apparatus including the above will be described with reference to the drawings. FIG. 47 shows the controller 230
48 is a block diagram of FIG. 48, and FIG. 48 shows a schematic configuration of the control unit 230. In FIG. 47, the control unit 230 includes a tank 1
3, a print head 2 that ejects ink from a nozzle 21 through a nozzle 21 onto a recording medium to perform printing, a print head driving unit 201 that drives the print head 2 in the main scanning direction, and it is necessary to determine when the tank 13 runs out of ink. A storage unit 202 for storing data and a horizontal detection unit 17 for detecting whether or not the inkjet recording device 600 is horizontally installed.
A vibration detecting means 18 for detecting a vibration generated in the ink jet recording apparatus 600, and an ink shortage display means 203 for displaying an ink shortage by the operation of the vibration detecting means 18,
Based on the detection result of the horizontal detection means 17, the horizontal detection display means 204 for displaying whether or not the inkjet recording device 600 is horizontally placed, and the respective input portion and / or output portion of the reaction force absorbing means 15 are provided. It is connected.

In FIG. 48, the control unit 230 is a central processing unit (CPU) that controls the entire ink jet recording apparatus 600.
Processing Unit) 231, read-only memories ROM1 to 4 (232 to 235) for storing a control program for the operation of the inkjet recording apparatus 600, and a random access memory RAM1 for temporarily storing various data.
And 2 (236 and 237), these memories (ROM / RAM) can be expanded as needed, like the external extended read-only memory EX-ROM 238.

The CPU 231 has ROMs 1 to 4 (232 to 232).
The control program stored in 235) is executed to give a command to each of the above drive systems. The stored control program is an executable file created by compiling a program previously described in a language such as C or assembler, and creating the result. The configuration of the print head 2 is similar to that shown in FIG. 6, and detailed description thereof will be omitted. The print head drive unit 201 is the drive circuit unit of the drive unit 52 shown in FIG. 46 and controls the control unit 23 during printing.
An ON signal is transmitted from 0 to the print head 2.

The storage means 202 stores a threshold value for determining ink shortage based on vibration detection by the vibration detection means 18 and previously measured data, and other data is also unused. Use space,
By newly providing a storage unit of the same type as the storage unit 202, the measurement data and the like can be added as needed.

In the present invention, examples of the data other than the above include average values of vibration data of the base 4 on which the print head 2 is mounted when ink is not exhausted. By using this average value for determining the ink shortage, it is possible to eliminate the influence of the variation of the vibration data of the base 4 and to perform the highly accurate ink shortage determination. In addition to this, if various patterns of data are stored in the storage means 202 and used, the accuracy of the discrimination is increased. The method of determining ink shortage will be described later.

As a device usable as the storage means 202, a large storage device such as a hard disk or a magneto-optical disk medium or a ROM which is usually used, or a ROM is used.
A discrete device such as a RAM or a RAM may be used, and various devices can be used without departing from the spirit of the present invention. The memory address of the storage means 202 is
It is not limited to the memory size or the memory arrangement. As an example, FIG. 49 shows a memory map in which the memory size is 8 Kbytes, but in the case of other memory sizes as well, data is allocated and stored in the same area size.

FIG. 49 shows the relationship (memory map) between the contents of the data stored in the storage unit 202 and the memory address, using a normal memory having a memory address of 0000h to FFFFh as the storage unit 202. This is an example. Here, data is allocated and stored for each memory address area.

Memory addresses 0000h to 1FFFh are threshold data areas to be compared when the reaction force absorbing means 15 is not provided, and 2000h to 3FFFh are tank 1's.
3 has ink and the reaction force absorbing means 15 has a measurement data area (this case will be described later) 4000h to 5FFFh is a vibration data area of the base 4 when the tank 13 is not attached, 6000h to FFFFh indicates an unused area provided for adding data in the future. Further, by expanding the new storage means 202 of the same format as the storage means 202 in addition to this unused area, various data can be allocated and stored in the storage area of the new storage means 202 for each address. is there.

As shown in FIG. 50, the horizontal detection means 17 has a semicircular weight 221, a detection case 222 that rotatably supports the weight 221, and a light emission disposed above the detection case 222. Element 223 and light receiving element 224
Detection case 2 that is made up of a pair of
22 are fixed to the four corners of the main body case 10. Light emitting element 2
A semiconductor laser or an LED is used as the light receiving element 224.
Is used as a photodiode. Aluminum or the like having a high reflectance is vapor-deposited on the flat surface 221a above the weight 221.

When the ink jet recording apparatus 600 is horizontal, as shown in FIG. 50 (a), the light emitted from the light emitting element 223 is reflected by the upper flat surface 221a of the weight 221 and is normally received by the light receiving element 224. However, if the ink jet recording apparatus 600 is tilted, FIG.
As shown in, the light reflected by the plane 221a cannot be detected by the light receiving element 224. In this way, the tilt of the inkjet recording device 600 can be detected by whether or not the reflected light from the weight 221 is received. Light receiving element 2
How much the tilt angle of the inkjet recording apparatus 600 detected by the 24 is set may be appropriately determined according to specifications and the like. Note that ultrasonic waves or the like can be used instead of the above optical detection means.

Next, an example in which the vibration detecting means 18 is used as the horizontal detecting means 17 will be described below with reference to FIG. In this example, the horizontal detecting means 17 may be installed at one place. Inkjet recording device 600
Is installed horizontally, the above-mentioned vibration detecting means 18
As shown in FIG. 51A, a vibration waveform centered on the base line “0” is observed as the output of FIG. 51A. However, when the inkjet recording apparatus 600 is tilted, as shown in FIG. The output of the vibration detecting means 18 is shifted and observed. Therefore, by detecting the shift amount S, it is possible to know whether or not the inkjet recording device 600 is tilted. The shift amount S is detected by the print head 2
It is not necessary to carry out after the start of driving, and it becomes possible by detecting the DC component from the vibration detecting means 18. Further, a threshold value may be set and compared with the shift amount S to determine whether or not the inkjet recording device 600 is tilted.

The detection result of the horizontal detection means 17 is transmitted to the horizontal detection display means 204. Whether or not the inkjet recording device 600 is installed horizontally is largely related to the vibration detection result of the entire inkjet recording device 600. Therefore, before the print head 2 is driven, the inkjet recording device 600 is installed horizontally. It is preferable to obtain the vibration detection data at. The drive of the print head 2 is not started unless the horizontal detection unit 17 detects that the inkjet recording device 600 is installed horizontally.

The vibration detecting means 18 detects a change in vibration caused by the tank 13 mounted on the print head 2 by using the acceleration sensor 210 shown in FIG. 52, for example. As described above, in the method of driving the print head 2 in the main scanning direction, the ink jet recording apparatus 600 vibrates when the scanning direction is reversed. The magnitude of this vibration is represented by mα where m is the mass of the base 4 and α is the acceleration. When the tank 13 is sufficiently filled with ink, the mass of the base 4 is heavy and the vibration generated in the inkjet recording apparatus 600 is large, but as the ink is consumed, the mass of the base 4 becomes light and the vibration is small. Become. Therefore, by detecting the vibration generated in the ink jet recording apparatus 600 and comparing this signal with a preset threshold value, it becomes possible to determine the presence or absence of the remaining amount of ink in the tank 13. In FIG. 52, the acceleration sensor 2
10 is the inertia weight body 212, the spring 213, and the damper 21.
4. Acceleration sensing element 215 and case 216 for supporting these inside, and spring 213 and damper 214
The amount of displacement of the inertial weight body 212 due to the vibration can be detected by the acceleration detection element 215. The signal detected by the acceleration detection element 215 is processed by the acceleration detection circuit shown in FIG. 53, and the detection result signal is output to the ink out display unit 203. The operation of the acceleration detection circuit will be described below.

In FIG. 53, first, the acceleration detecting element 2
The subtractor 216 performs subtraction processing on the signal detected by 15. This subtraction process is a process of subtracting the vibration of only the base 4 when the tank 13 is not mounted from the detection signal, and is stored in the storage unit 202 and is stored in the base 4 when the tank 13 is not mounted. The subtraction process is executed using the vibration data. By this subtraction processing, the vibration caused only by the tank 13 can be extracted.

Since the output signal of the subtractor 216 is a minute signal, it is then amplified by the amplifier 217 by about 10 times.
As the amplifier 217, a commonly used operational amplifier (operational amplifier) can be mentioned. Further, the output signal of the amplifier 217 is input to the comparator 218. The comparator 218 compares the output signal of the amplifier 217 with the threshold value stored in the storage means 202. The comparator 218 may be a commonly used comparator.
The threshold value used for the comparison is, for example, vibration data when the ink remains in the tank 13 by 10% or more of the tank capacity. When the ink in the tank 13 is consumed, the vibration of the tank 13 becomes small. Therefore, the comparator 218 compares the detection signal with the threshold data, and the detection signal is equal to or smaller than the threshold data. In this case, it is determined that the ink has run out, and the output signal is displayed as the out-of-ink display means 2.
Send to 03. On the contrary, when the threshold value data is smaller than the detection signal, it is determined that the ink remains in the tank 13, and the vibration detection operation is continued.

The ink shortage display means 203 and the horizontal detection display means 204 display the detection results of the vibration detection means 18 and the horizontal detection means 17, respectively, and are turned off in the initial state using, for example, LEDs. Then, even when the detection result is normal, it is kept off, and only when the detection result is abnormal, for example, the operation of turning on green is performed. Depending on the state of the LED, the user can determine whether the ink is exhausted and the ink jet recording apparatus 6
It is possible to recognize whether or not 00 is installed horizontally.

Further, as described above, by providing the horizontal detecting means 17 at each of the four corners of the ink jet recording apparatus 600, even when one of the four horizontal detecting means 17 is installed with a slight inclination, The configuration is such that the installation surface that is not horizontal can be identified by lighting the LED. Further, the ink shortage display means 203 and the horizontal detection display means 204 may be combined into a single liquid crystal display unit of about 3 inches to display respective messages.

According to the above-described embodiment, the vibration detecting unit 18 uses the threshold value stored in the storage unit 202 and the vibration data generated in the ink jet recording apparatus 600 (the base when the ink tank is not mounted). By comparing with (value obtained by subtracting the vibration of 4), it is possible to promptly detect whether or not the ink is exhausted, and at the same time, display the ink exhaustion. Further, it is possible to detect whether or not the inkjet recording device 600 is installed horizontally and display the result promptly. In addition, the user can recognize the timing of the replacement of the tank 13 by displaying the ink shortage, and know whether or not ink remains in the tank 13 from the outside even when the inkjet recording device 600 is in the operating state. You can As a result, even during printing, it is possible to continue the tank 13 or the printing process interrupted by the tank 13 replacement.

When it is determined that the ink has run out, the ink jet recording apparatus 600, as described in the second embodiment.
Is stopped, and the position of the base 4 and print data are stored in the storage unit 202. When the replacement of the tank 13 is completed and it is detected that the tank 13 is properly mounted, the printing operation by the print head 2 is restarted. Further, by displaying the detection result as to whether or not the inkjet recording device 600 is installed horizontally, it is possible to remove in advance the influence other than the vibration due to the scanning of the base 4 on which the print head 2 is mounted before the print head 2 is driven. Therefore, it is possible to easily extract the vibration generated in the inkjet recording device 600 when the ink runs out. Further, since the vibration detecting means 18 is composed of one vibration sensor, access to the data stored in the storage means 202 is less than in the conventional method, and the user can immediately recognize the ink shortage. .

The reaction force absorbing means 15 described in the second embodiment may be added to the ink jet recording apparatus 600 which is the embodiment of the present invention. A method of detecting the presence / absence of the remaining amount of ink in this configuration will be described below. As described in the second embodiment, the vibration generated in the entire inkjet recording apparatus 600 when the base 4 is driven is detected by the vibration detection unit 18, and the reaction force absorption unit 15 is driven to cancel the vibration. Data (calibration value) is obtained in advance and stored in the storage unit 202.

In the ink jet recording apparatus 600, when the vibration is detected by the vibration detecting means 18, the drive data of the reaction force absorbing means 15 corresponding to the detection result is read out from the storing means 202, and the reaction force absorbing means 15 is driven. Since the drive control is performed, it is possible to suppress the vibration generated in the inkjet recording device 600. When the remaining amount of ink in the tank 13 becomes small, the vibration generated in the ink jet recording apparatus 600 becomes small. Therefore, the reaction force absorbing means 15 is controlled so that its speed becomes slow. However, when the vibration becomes smaller than a certain threshold value (the remaining amount of ink becomes smaller than a certain value), the drive control of the reaction force absorbing means 15 becomes impossible, and as a result,
The vibration generated in the inkjet recording device 600 cannot be canceled. Therefore, the vibration which cannot be canceled is detected by the vibration detecting means 18 to judge the ink shortage. The vibration threshold value is stored in the storage unit 202 together with the drive data of the reaction force absorbing unit 15.

Further, in the ink jet recording apparatus 600,
You may apply the structure which consists of the main tank 6 and the sub tank 3 shown in FIG. That is, when the vibration detector 18 detects that the ink in the sub tank 3 is exhausted, the ink is immediately supplied from the main tank 6 to the sub tank 3, so that it is not necessary to replace the ink tank. Further, since air is prevented from being mixed with the ink due to the replacement of the ink tank, the maintenance becomes easy and the ink can be effectively used.

As described above, according to the present invention, a plurality of sensors are installed in the ink tank, and the remaining amount of ink in the ink tank is detected while exchanging data with a memory or the like, as compared with the conventional method. The operation of the control unit, such as the exchange of data with the memory, is simplified, and the time for the user to recognize the ink exhaustion can be shortened. In addition, it can respond to the vibration detection of inkjet recording devices of various configurations, and because the processing is performed by subtracting the vibration of only the base without ink tank installed, it is possible to judge the ink exhaustion by extracting the vibration of only the ink tank. it can.

In the present invention, the reaction force absorbing means 15
It is also possible to provide the inkjet recording device 6
The vibration of the whole 00 can be suppressed. Therefore, the vibration detection unit 18 can reliably detect vibrations below a certain level due to ink shortage. Further, a storage unit 202 for storing the vibration detection determination data is provided, and the vibration detection determination is performed by comparing the determination data with the vibration detection result. Therefore, based on various data measured in advance. Unnecessary vibrations can be removed to enable highly accurate vibration detection.

In the present invention, the ink shortage display means 203 for displaying the ink shortage based on the vibration detection result can be used to constantly monitor the ink shortage from the outside. Also,
By providing the horizontal detection unit 17, the inkjet recording device 600 can be used always in a stable state. Before operating the inkjet recording device 600, the horizontal recording means 17 is used to operate the inkjet recording device 6
Inkjet recording device 60 by detecting the mounting state of 00
By correctly setting 0, external influences other than the vibration due to the scanning of the base 4 on which the print head 2 is mounted can be suppressed in advance, and the vibration due to the scanning of the base 4 can be detected more accurately. it can.

The first to third embodiments described above can be appropriately combined and used without departing from the gist of the present invention.

[0162]

According to the invention of the first aspect, the auxiliary tank is
Ink level from the print head to a constant level.
The ejection can be performed in a stable state. Also,
Compression / decompression operation of the ink holder and ink transfer described above
By combining the ink supply methods by means,
A constant amount of ink can always be supplied to the tank,
It is possible to prevent the ink from leaking from the cheat .

According to the inventions of the second to sixth aspects,
Ink efficiently and stably supplied to the print head, and also the ink jet recording apparatus capable of high-quality image formation
It can lath.

[Brief description of drawings]

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

FIG. 2 is an enlarged plan view showing the vicinity of a print head and a main tank of the inkjet printer of FIG.

FIG. 3 is a front view of FIG.

FIG. 4 is a perspective view showing an example of a configuration of a print head and a sub tank of FIG.

FIG. 5 is a perspective view showing another configuration example of the print head and the sub tank of FIG.

6 is a cross-sectional view illustrating the structure of nozzles of a print head used in the inkjet printer of FIG. 1 and the principle of ink ejection.

7 is a perspective view showing the outer appearance of a main tank, a sub tank, and an ink transfer unit used in the inkjet printer of FIG.

FIG. 8 is a side sectional view of FIG.

9 is a perspective view showing a part of the pump of FIG. 7 by cutting out.

10 is a horizontal cross-sectional view of the pump of FIG.

FIG. 11 is a vertical cross-sectional view illustrating a needle insertion / extraction mechanism applied to the inkjet printer of the present invention.

FIG. 12 is a vertical sectional view for explaining the operation of another needle insertion / extraction mechanism of the present invention.

13 is a cross-sectional view showing an opening / closing operation of a valve arranged in the ink supply passage of FIG.

FIG. 14 is a plan view of needle position detecting means for detecting the state of the needle inserted into and removed from the sub tank.

FIG. 15 is a cross-sectional view illustrating an operation of supplying ink to the sub tank by the ink transfer unit.

FIG. 16 is a perspective view showing the outer appearance of a main tank / sub tank and ink transfer means of an inkjet printer according to another embodiment of the present invention.

FIG. 17 is a perspective view showing the pump of FIG. 16 with a part thereof cut away.

18 is a perspective view showing the configuration of the needle of FIG.

FIG. 19 is a perspective view showing the outer appearance of a main tank / sub tank and ink transfer means of an ink jet printer according to another embodiment of the present invention.

20 is a perspective view showing a part of the pump shown in FIG. 19 by cutting away.

FIG. 21 is a perspective view showing an outer appearance of a main tank / sub tank and ink transfer means of an inkjet printer according to another embodiment of the present invention.

22 is a perspective view showing a part of the pump shown in FIG. 21 by cutting away.

23 is a horizontal cross-sectional view of the pump of FIG.

FIG. 24 is a perspective view showing the outer appearance of a main tank / sub tank and ink transfer means of an inkjet printer according to another embodiment of the present invention.

25 is a perspective view showing a part of the pump of FIG. 24 by cutting away.

FIG. 26 is a horizontal cross-sectional view of the pump of FIG.

FIG. 27 is a side view of the flow path cross-sectional area adjusting means used in the inkjet printer of the present invention.

28 is a flowchart for explaining the ink supply operation of the present invention and the operation of the flow path cross-sectional area adjusting means of FIG. 27.

FIG. 29 is a perspective view showing the structure of a needle according to an embodiment of the present invention.

FIG. 30 is a perspective view showing the structure of a needle according to another embodiment of the present invention.

FIG. 31 is a perspective view showing the structure of a needle according to another embodiment of the present invention.

FIG. 32 is a perspective view showing the structure of a needle according to another embodiment of the present invention.

FIG. 33 is a perspective view showing the structure of a needle according to another embodiment of the present invention.

FIG. 34 is a perspective view showing an overall configuration of an inkjet printer according to another embodiment of the present invention.

FIG. 35 is a side view of the facing member of FIG. 34.

FIG. 36 is a diagram showing a configuration example when an optical detection method is used as the remaining ink amount detection means in FIG. 34.

FIG. 37 is a side view showing an example of the configuration of a weight sensor as the remaining ink amount detecting means in FIG. 34.

38 is a cross-sectional view showing an example of the internal structure of the weight sensor main body shown in FIG. 37.

39 is a perspective view showing an example of the configuration of the reaction force absorbing means of FIG. 34. FIG.

40 is a perspective view showing an example of another configuration of the reaction force absorbing means of FIG. 34. FIG.

41 is a view for explaining the mechanism of the reaction force absorption means of FIG. 40. FIG.

42 is a block diagram showing an example of a configuration of a control unit used in the inkjet printer of FIG. 34.

43 is a flowchart illustrating the operation of the control unit of FIG. 34.

FIG. 44 is a perspective view showing an example of a configuration of reaction force absorbing means according to another embodiment of the present invention.

45 is a flow chart for explaining the operation of the reaction force absorbing means of FIG.

FIG. 46 is a perspective view showing an overall configuration of an inkjet printer according to another embodiment of the present invention.

47 is a block diagram showing an example of a configuration of a control unit used in the inkjet printer of FIG. 46.

48 is a block diagram showing a schematic configuration of a main part of a control unit in FIG. 47.

FIG. 49 is a diagram showing an example of a memory map of a storage unit of the control unit of FIG. 47.

50 is a diagram for explaining the operation of the horizontal detecting means in FIG. 46.

51 is a diagram illustrating a detection method when a vibration detection unit is used as the horizontal detection unit in FIG. 50.

52 is a sectional view of the vibration detecting means of FIG. 46.

53 is a diagram showing a circuit configuration of the vibration detecting means of FIG. 52.

[Explanation of symbols]

2 print head 3 sub tank 4 base 5 print head moving means 6 main tank 7 ink transfer means 8 needle (conduit) 200 ink jet printer (ink jet recording apparatus) 400 ink jet printer (ink jet recording apparatus) 600 ink jet printer (ink jet recording apparatus)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroo Matsumoto 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Sharp Corporation (56) References JP-A-5-238017 (JP, A) JP-A-7 -47690 (JP, A) JP 10-235892 (JP, A) JP 58-194560 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/175 B41J 2/01

Claims (20)

(57) [Claims] 1. A print head for ejecting ink droplets onto a recording medium, a sub tank for storing ink supplied to the print head, and a print head and a sub tank for mounting the print head at a printing position and a return position. And an ink transfer means for transferring ink from the main tank to the sub tank at the return position, and a main head with which the sub tank engages at the return position of the print head. Is an excess ink that is returned from the sub tank to the main tank to make the liquid level of the sub tank constant, and the sub tank holds the ink and is elastically deformable.
A holder is installed inside the main tank or near the main tank.
A pressing member that can press the ink holder in the sub tank
Is provided, the ink holding member, when the sub tank is engaged with the main tank,
It is pressed by the pressing member and held inside the ink holder.
The ink level rises and the sub tank is separated from the main tank.
When the pressure is applied, the pressure applied by the pressure member is released and restored.
The negative pressure generated inside the holder
An ink jet recording apparatus characterized in that ink is absorbed by an ink holder . 2. A conduit for ink transfer means, the tip of which is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and one end of which is connected to the base end of the conduit and the other end of which is inside the main tank. From the elastically deformable tube opened to the front and the ironing pump that sucks the excess ink of the sub tank to the main tank after ejecting the ink of the main tank to the sub tank by squeezing the tube in the forward and reverse directions by the rotor The inkjet recording apparatus according to claim 1, wherein 3. The ink transfer means is connected to at least two conduits whose front end is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and one end is connected to each base end of these conduits. In addition, at least two elastically deformable tubes having the other end opened in the main tank, and squeezing these tubes in one direction by the rotor to eject the ink of the main tank to the sub tank and at the same time excess the sub tank. The ink jet recording apparatus according to claim 1, further comprising an ironing pump that sucks the ink of 1. into the main tank. 4. The ink transfer means has a conduit whose tip is inserted into and removed from the sub tank when the sub tank is engaged with the main tank, and one end of which is connected to the base end of the conduit and the other end of which is inside the main tank. It consists of an elastically deformable tube opened to the side and an ironing and squeezing pump that makes the tube unidirectional by a rotor. At least two ironing pumps are used, and one of the squeezing pumps makes one tube unidirectional by the rotor. The ink jet recording apparatus according to claim 1, wherein the ink in the main tank is discharged to the sub tank, and the other ironing pump draws the other tube in one direction by the rotor to suck the excess ink in the sub tank to the main tank. . 5. The ink transfer means discharges the ink in the main tank to the sub tank until the liquid surface is formed above the tip of the conduit inserted in the sub tank, and the liquid level of the ink in the sub tank The ink jet recording apparatus according to any one of claims 1 to 4, wherein the ink in the sub tank is sucked into the main tank at least until the ink has dropped to the tip of the conduit. 6. A deformable member from a main tank to a sub tank, wherein a deformable member having flexibility is disposed on an outer surface of the sub tank, and the pressing member presses and deforms the ink holding body via the deformable member. claims 1 consisting of protruding projections toward the
5. The inkjet recording device according to any one of 5 to 5 . 7. The ink jet recording according to any one of claims 1 to 5, wherein the pressing member is the conduit that is inserted into and removed from the sub tank, and the conduit directly presses the upper portion of the ink holder. apparatus. 8. The conduit is a swing arm having one end holding the conduit and the other end pivotally supported, and the swing arm is normally rotated when the print head returns to the return position so that the conduit is in the sub tank. The ink jet recording according to any one of claims 2 to 7 , wherein the ink jet recording is supported by a conduit insertion / removal mechanism that is inserted into a sub tank by reversing the swing arm when the print head separates from the return position. apparatus. 9. A two conduits ink discharge conduit and the ink suction conduit in the ink transfer means, they jet recording apparatus according to any one of claims 3 formed integrally 8 . 10. An ink transfer means is disposed in a flow path between an ink discharge conduit or ink suction conduit and an ironing pump, and a flow path cross sectional area adjusting means for adjusting the cross sectional area of this flow path by expansion and contraction is provided. The flow path cross-sectional area adjusting means is formed such that the amount of expansion and contraction thereof is larger than the flow path volume from the flow path cross-sectional area adjusting means to the tip of the ink discharge conduit / ink suction conduit. The inkjet recording apparatus according to claim 9 , wherein 11. The ink jet recording apparatus according to claim 10 , wherein the flow path cross section adjusting means is drive-controlled in synchronization with the print head moving means. 12. The ink jet recording apparatus according to claim 10 , wherein the flow path sectional area adjusting means is controlled to be reduced after it is detected that at least the conduit is inserted into the sub tank. 13. The sub-tank comprises a plurality of ink tanks, and has an ink remaining amount detecting means for generating a signal when the remaining amount of ink in any one of these sub-tanks is low. 13. The inkjet recording device according to any one of 1 to 12 . 14. is arranged in a channel that connects the sub tank and the print head, the ink jet recording apparatus according to claim 1, further comprising a flow path opening and closing means being closed opening in response to insertion of the conduit with respect to the sub-tank . 15. A conduit comprising a bent tube body and an opening formed in the vicinity of the bent portion of the tube body, wherein one side of the tube body is used as an ink discharge conduit and the other side is used for ink suction. and conduit, the conductance of the ink discharge conduit Cin, the conductance of the ink suction conduit Cout, the conductance of the opening when the Cop, claim 2 which is configured so as to satisfy the Cop> Cout ≧ Cin 14 5. The inkjet recording device according to any one of 1. 16. A printing method for ejecting ink droplets onto a recording medium.
Head and a sub-device that stores the ink supplied to the print head.
Print head and sub tank
Print head move to move the print head between the print position and the return position.
The moving means and the sub tank are engaged at the print head return position.
In the main tank and the return position, the ink in the main tank is
And an ink transfer means for transferring the ink to the print head, and is arranged in the flow path connecting the sub tank and the print head.
Opening / closing of the flow path that is closed / opened according to the insertion / extraction of the conduit to / from the tank
Means for supplying the excess ink from the sub tank to the main ink.
When the sub tank is returned to the tank and the liquid level of the sub tank is made constant and the sub tank is engaged with the main tank by the ink transfer means.
The conduit into which the tip is inserted and removed from the sub tank, and the end
Connected to the base end of the pipe and opened the other end into the main tank
Elastically deformable tube and tube
・ The ink in the main tank is discharged to the sub tank by squeezing in the opposite direction.
After that, suck the excess ink from the sub tank to the main tank
An ink jet recording apparatus comprising a squeezing pump . 17. A printing method for ejecting ink droplets onto a recording medium.
Head and a sub-device that stores the ink supplied to the print head.
Print head and sub tank
Print head move to move the print head between the print position and the return position.
The moving means and the sub tank are engaged at the print head return position.
In the main tank and the return position, the ink in the main tank is
And an ink transfer means for transferring the ink to the print head, and is arranged in the flow path connecting the sub tank and the print head.
Opening / closing of the flow path that is closed / opened according to the insertion / extraction of the conduit to / from the tank
Means for supplying the excess ink from the sub tank to the main ink.
When the sub tank is returned to the tank and the liquid level of the sub tank is made constant and the sub tank is engaged with the main tank by the ink transfer means.
At least two of which the tip is inserted into and removed from the sub tank
Conduits and one end connected to each proximal end of these conduits and the other
At least an elastically deformable end with an opening in the main tank
Two tubes and these tubes are combined by a rotor.
Direction, do not discharge the ink from the main tank to the sub tank.
At the same time, the excess ink in the sub tank is sucked into the main tank.
An ink jet recording apparatus comprising a squeezing ironing pump . 18. A printing method for ejecting ink droplets onto a recording medium.
Head and a sub-device that stores the ink supplied to the print head.
Print head and sub tank
Print head move to move the print head between the print position and the return position.
The moving means and the sub tank are engaged at the print head return position.
In the main tank and the return position, the ink in the main tank is
And an ink transfer means for transferring the ink to the print head, and is arranged in the flow path connecting the sub tank and the print head.
Opening / closing of the flow path that is closed / opened according to the insertion / extraction of the conduit to / from the tank
Means for supplying the excess ink from the sub tank to the main ink.
When the sub tank is returned to the tank and the liquid level of the sub tank is made constant and the sub tank is engaged with the main tank by the ink transfer means.
The conduit into which the tip is inserted and removed from the sub tank, and the end
An ammunition connected to the base end of the pipe and open at the other end in the main tank
The tube that can be elastically deformed and the tube
It consists of a squeezing pump and a squeezing pump.
One ironing pump is used to
The main tank by squeezing one tube in one direction with the rotor
Ink is discharged to the sub tank and the other ironing pump
Rotate the other tube in one direction with the rotor
Characteristic of sucking excess ink in the main tank
An ink jet recording apparatus according to. 19. A printing method for ejecting ink droplets onto a recording medium.
Head and a sub-device that stores the ink supplied to the print head.
Print head and sub tank
Print head move to move the print head between the print position and the return position.
The moving means and the sub tank are engaged at the print head return position.
In the main tank and the return position, the ink in the main tank is
And an ink transfer means for transferring the ink to the print head, and is arranged in the flow path connecting the sub tank and the print head.
Opening / closing of the flow path that is closed / opened according to the insertion / extraction of the conduit to / from the tank
Means for supplying the excess ink from the sub tank to the main ink.
Back to the tank to keep the liquid level in the sub tank constant and the ink transfer means is the tip of the conduit inserted in the sub tank.
Ink in the main tank until the liquid level is formed above the
Ink level in the sub tank and
Even if the ink in the sub tank is not
An inkjet recording device that sucks into a tank . 20. A printing method for ejecting ink droplets onto a recording medium.
Head and a sub-device that stores the ink supplied to the print head.
Print head and sub tank
Print head move to move the print head between the print position and the return position.
The moving means and the sub tank are engaged at the print head return position.
In the main tank and the return position, the ink in the main tank is
And an ink transfer means for transferring the ink to the print head, and is arranged in the flow path connecting the sub tank and the print head.
Opening / closing of the flow path that is closed / opened according to the insertion / extraction of the conduit to / from the tank
Means for supplying the excess ink from the sub tank to the main ink.
Back to the tank to keep the liquid level in the sub tank constant, and the sub tank consists of multiple ink tanks.
Ink is low on one of the
Ink remaining amount detection means that generates a signal when
Inkjet recording device characterized by: