JPH0478541A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To surely perform capping and prevent a poor ink delivery by vibrating a recoring head means by a driving means after covering action of the cap. CONSTITUTION:A carrier is moved to a home position by performing a position detection of the carrier by means of a carrier home sensor 21. Then, a motor 28 of a recovery system is driven to actuate a cap 22 in such a way that the cap 22 covers an outlet forming face of a recording head 1. In this time, if the carrier 2 positions accurately at the home position, a projected part 24 fits to a recessed part 5 but if the position is deviated, it does not fit and the cap 22 does not cover the outlet forming face either. Then, the carrier 2 is moved to the left direction and the right direction. Namely, such a control that vibrates the carrier 2 at the home position is performed. By performing this vibration control, even if the position of the cap is deviated by inferiority and assembling error of the carrier home sensor 21, the projected part 24 is fitted to the recessed part 5 and it is possible to bring surely the cap 22 into contact with the recording head 1 and to prevent a poor ink delivery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device.

[Conventional technology]

2. Description of the Related Art Conventionally, recording apparatuses that perform recording on recording media such as paper and OHP sheets (hereinafter also referred to as recording paper or simply paper) have been proposed in the form of mounting recording heads using various recording methods. These recording heads include those based on a wire tod type, a thermal type, a thermal transfer type, and an inkjet type.

In particular, the inkjet recording method jets ink directly onto the recording paper, so running costs are low.
It is attracting attention as a quiet recording method.

In such an inkjet recording device,
Generally, a recording head with an array of fine ejection ports is used. Therefore, it is necessary to refresh the ink when air bubbles or dust enter the ejection port, or when the ink becomes unsuitable for ejection or recording due to thickening caused by evaporation of the ink solvent. Accordingly, a process (ejection recovery process) is performed to remove these causes of ejection failure.

One form of means for performing such ejection recovery processing includes a cap that can cover the ejection port forming surface of the print head and a pump that communicates with the cap and applies suction force. Then, by driving the ink ejection energy generating element inside the ejection port toward the cap, ink is ejected from all the ejection ports (hereinafter referred to as preliminary ejection), or the ink is sucked while the ejection port forming surface is covered by the cap. The ink is forcibly discharged by applying force to perform suction from the ejection port, and the cause of the ejection failure is removed together with the ink (hereinafter referred to as suction recovery).

In addition, in order to avoid the effects of dust etc. that occur when the cap is opened and the recording head is exposed to the air, it is necessary to cap the recording head after turning on the power or during standby, and when the cap is opened during recording. In addition, a process is performed in which the recording head is capped (hereinafter referred to as capping) when data from the host device is interrupted for a certain period of time or more.

[Problem to be solved by the invention]

However, errors in the position of the recording head may occur due to defects in the detector for controlling the carriage position, assembly errors in the machine, or the like. At this time, when capping the ink ejection ports of the print head, the position of the ink ejection ports of the print head, that is, the position of the carriage on which the print head is mounted, and the position of the cap do not match, so the cap is not completed. do not have.

This has caused problems such as ejection failure due to thickening of ink and dust, and ink being unable to be suctioned through the cap when suction is restored.

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an inkjet recording apparatus that can perform capping reliably.

[Means for solving problems]

In order to solve the above problems, an ink jet recording apparatus of the present invention includes: a cap capable of covering an ink ejection orifice forming surface of a recording head means; a first engaging portion formed to interlock with the cap; When covering the ejection port forming surface of the recording head means, a second engaging part formed on the recording head means is formed to engage with the first engaging part, and after the covering operation of the cap, the recording head means It is characterized by comprising a driving means for swinging the.

[Effect]

According to the above configuration, since the driving means swings the recording head means after the cap covering operation, it is possible to engage the first engaging portion and the second engaging portion even when the recording head means is not in the correct position. With this, the cap can cover the ejection port forming surface of the recording head means.

Therefore, since capping can be performed reliably, ink ejection failure can be prevented.

〔Example〕

Embodiments of the inkjet recording apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the external configuration of an embodiment of the present invention.

Here, 1 is a head cartridge that has ink, an ink ejection port, and an electrical connection part inside, and 2 is a carrier for mounting the head cartridge and scanning in the direction of arrow A-E in the figure. 3 is a hook for attaching the head cartridge 1 to the carrier 2, and 4 is a lever for operating the hook 3.

Reference numeral 5 denotes a recess into which a protrusion 24 (to be described later) is inserted, and is formed on the carrier 2. Reference numeral 6 denotes a support plate that supports the electrical connection to the head cartridge 1.

7 is a flexible cable for connecting the electrical connection section and the main body control section. A guide shaft 8 is inserted through the carrier 2 to guide the carrier 2 in the direction A-B. Reference numeral 9 denotes a timing belt to which the carrier 2 is fixed and which transmits power for moving the carrier 2 in the direction A-B, and is stretched around pulleys 10A and IOB arranged on both sides of the device. Driving force is transmitted to one pulley 10B from the carrier motor 11 via a transmission mechanism such as a gear. 12 is a recording medium such as paper (hereinafter also referred to as recording paper)
It is a platen roller that regulates the recording surface of the printer and transports it during recording, etc., and the transport motor 1
3. 14 is a paper pan for guiding the recording medium to the recording device; 15 is a feed roller disposed in the feeding path of the recording medium to press the recording medium toward the conveyance roller 12 and convey it. .

Reference numeral 16 denotes a paper discharge roller that is disposed downstream of the recording position in the recording medium conveyance direction and discharges the recording medium toward a paper discharge port (not shown). Reference numeral 17 denotes a spur provided corresponding to the paper ejection roller 16, which connects the paper ejection roller 16 via the recording medium.
is pressed to generate a force for conveying the recording medium by the paper ejection roller 16. A platen 18 is provided at a position facing the ink ejection opening of the head cartridge 1, and presses the recording medium against the paper pan front part 19 by an elastic member (not shown).

This apparatus employs an inkjet recording head that performs recording by ejecting ink. Therefore, the distance between the ink ejection ports of the print head and the recording surface of the print medium is relatively small, and the sensation must be strictly controlled to avoid contact between the print medium and the ejection ports. Part 19
It is effective to regulate the position of the recording medium. 20 is a feed roller 15 and a spur 1 when the recording medium is attached and detached.
7. A release lever for releasing each bias of the platen 18. Reference numeral 21 denotes a sensor for detecting the position of the carrier 2, which detects the position of the carrier 2 by passing through a convex portion (not shown) of the carrier 2.

22 is the head cartridge 1 at the home position.
It is a cap formed of an elastic material such as rubber, and is provided at a position facing the ink ejection orifice forming surface, and is supported so as to be able to come into contact with and detach from the head cartridge 1. This cap 22 is used to protect the ink ejection ports of the head cartridge 1 during non-printing times and during ejection recovery processing. Ejection recovery processing is a process in which ink is ejected from all ejection ports by driving an energy generating element provided inside the ejection ports and used for ink ejection.
Preliminary ejection), or by applying suction force to the ejection port formation surface with the cap covering it, the ink is forcibly discharged by suctioning from the ejection port (suction recovery), which may cause air bubbles, dust, or increased viscosity. This process removes the causes of ejection failure of ink that has become unsuitable for printing. A pump 23 is used to apply a suction force for forcibly discharging the ink and to attract the ink received in the cap 22 during ejection recovery processing by such forced ejection or ejection recovery processing by preliminary ejection. This pump 23
A convex portion 24 that fits into the concave portion 5 of the carrier 2 is formed on the outside of the carrier 2 . 25 is a waste ink tank for storing the waste ink sucked by the pump 23, and 26 is a tube that communicates the pump and the waste ink tank 25. Reference numeral 27 denotes a blade for wiping the ejection port forming surface of the head cartridge 1, which protrudes toward the head cartridge 1 side and engages with the ejection port forming surface at a position for wiping during the movement of the head cartridge 1. It is movably supported in a retracted position and not in a retracted position. 28 is a recovery system motor, and 29 is a cam device for receiving power transmitted from the recovery system motor 28 to move the drive system of the pump 23, the cap 22, and the blade 27, respectively.

Next, details of the above-mentioned head cartridge 1 will be explained.

FIG. 2 is an external perspective view of the head cartridge 1 in which the ejection unit 1a and the ink tank 1b, which form the main body of the inkjet recording head, are integrated. In the figure, reference numeral 1e denotes a pawl that is hooked by a hook 3 provided on the carrier 2 when the head cartridge 1 is mounted. As is clear from the figure, the pawl 1e is disposed inside the entire extension of the recording head. In addition, in front of the head cartridge 1 and near the ejection unit 1a, a positioning abutment part is provided, although not shown in this figure. 1f is carrier 2
This is a head opening into which a support plate 6 that stands upright and supports a flexible board (electrical connection part) and a rubber pad is inserted.

FIG. 3 is a sectional view showing the structure of the cap 22 and the like.

In this embodiment, the ink suction port 221 in the cap 22 is opened vertically at the bottom, and an ink flow path 224 is formed toward the ink introduction port 223 provided in the action portion 222 of the cap lever. Further, the suction port 221 is not completely covered by the suction body 225.

According to this configuration, even if ink ejected during ejection recovery processing or the like flows downward due to gravity, the ink is sucked from the suction port 221 provided below, so the ink suction body 2
The amount of ink remaining in 25 is significantly reduced. Therefore, deterioration due to solidification can be significantly delayed, and the life of the ink suction body 225 or the cap 22 to which it is attached can be extended.

FIG. 4 is an explanatory diagram showing the axial curves of each cam of the cam device 29 and the operating positions of each part corresponding to each cam position.

In the same figure, (a) shows the cam position and the state of each part when performing a recording operation, and shows the cap 22 and the blade 27.
is separated from the ejection port forming surface of the recording head, and the pump 23 is at the top dead center. Further, the convex portion 24 is also spaced apart from the concave portion 5 of the carrier 2.

(b) is the position where the home position switch 30 is turned off, and this position is taken as the home position of the cam device 29. This is a position set during recording standby, etc. At this time, the cap 22 covers the discharge port forming surface, the blade 27 is retracted, and the pump 23 is also at the top dead center. Further, the convex portion 24 engages with the concave portion 5 of the carrier 2 to restrict movement of the carrier 2.

The cam is rotated from position [(b) (and the cap 22 is joined to the discharge port forming surface (cap on), and the piston 231 moves toward the bottom dead center while the convex part 24 is engaged with the concave part 5. Then, the negative pressure in the suction system leading to the cap 22 increases.The piston 231 eventually reaches the ink inlet of the pump 23 and after a period of blocking it (a period in which the valve is closed), the valve closes. Starts to open, fully opens, then piston 23
1 reaches position (C) near the bottom dead center. Sufficient suction (suction recovery) is achieved by stopping the rotation of the cam at this position for a predetermined period of time in consideration of the fluid resistance of the ink suction system.

After that, when the cam is rotated again, the piston 231
reaches the bottom dead center, and the cap 22 reaches the discharge port forming surface, the convex portion 2
4 begins to separate from the recess 5. This position (d) is maintained for a predetermined time.

When the cam is then rotated further, the piston 231 begins to move toward top dead center again. During this process the valve begins to close and then reaches a point where it is completely occluded.

On the other hand, the cap 22 is completely separated from the discharge port forming surface at position (e). By driving the piston 231 several times in this vicinity, the ink remaining in the ink suction system is suctioned (empty suction) to the pump side. Note that the space on the left and right of the piston 231 inside the pump is
They are communicated through a flow path (not shown), which is closed when the piston moves from the top dead center to the bottom dead center, and is opened when the piston moves from the bottom dead center to the top dead center. Further, the space on the right side of the piston communicates with a flow path provided in the pump shaft 232. Therefore, when the piston 231 moves from the bottom dead center to the top dead center in the process of empty suction, the ink introduced into the space on the left side of the piston is transferred to the space on the right side, and when the piston 231 moves from the top dead center to the bottom dead center, the ink Ink is introduced from the suction system into the left-hand space, and ink is discharged from the right-hand space into the waste ink tank.

After that, when the cam is further rotated in the forward direction, the blade 27 protrudes and becomes ready for wiping (position (f)
)). When the carrier 2 is moved toward the recording area in this state, the blade 27 engages with the ejection port forming surface of the head and wipes the surface, thereby wiping away ink and the like adhering to the ejection port forming surface. Then, the cam is further rotated to move the blade 27 back and set the cam to position (a). In this state, the carrier 2 is moved toward the cap so that the ejection port forming surface of the head faces the cap 22. Thereafter, the cam is moved to position (b) to turn on the cap, and the convex portion 24 is engaged with the concave portion 5 to be stopped.

Note that when transitioning from standby state to recording, position (b)
The cam may be rotated in the positive or negative direction to cause the blade 27 to protrude, perform wiping, and then perform recording.

Next, a control configuration for controlling each part of the embodiment configured as described above will be explained with reference to FIG.

In the figure, 100 is a CP that executes various control procedures.
U, 101 is a ROM that stores the above control procedures, data, etc.
, 102 is a RAM used for storing the current position of the carrier 2 and as a work area for executing the above control.

Among the 11th J configurations described above, CPU 1. OO
The head cartridge (recording head) 1, carrier motor 11, transport motor 13, and recovery system motor 28 are controlled by the head driver IA, respectively.
Driven by motor drivers IIA, 13A, 28A. Further, the CPU 100 can recognize the cap position and the moving position of the carriage 2 based on the detection by the recovery system home sensor 30 and the carrier home sensor 21.

Next, the control procedure of the ejection recovery process controlled by the CPU 100 will be described with reference to flowcharts and timing charts shown in FIGS. 6 to 8 and 9, respectively.

In FIG. 6, first, in step S1, the carrier 2 is moved to the home position and the cap 22 is attached to the recording head 1.
After making contact with the carrier 2, the carrier 2 is swung. This results in
This enables the cap 22 to reliably cover the ejection port forming surface of the recording head 1, and details of this capping method will be described later.

Thereafter, the process advances to step $2 and waits for a predetermined time. This is because the cap 22 is attached to the recording head 1 in step S1.
The cap 22, which is made of an elastic material such as rubber, is temporarily deformed due to the load generated by the carrier 2 moving while in contact with the carrier 2. .3 seconds).

Next, the process advances to step S3, and when the deformation of the cap 22 is restored, a discharge recovery process is performed using the suction means. That is, the CPU 10 drives the recovery system motor 28 to control the position of the cam device 29 to the suction recovery position (C), thereby performing suction recovery.

FIG. 7 shows details of step Sl in FIG. 6,
7 is a flowchart showing details of a capping control procedure for ensuring that the cap 22 covers the ejection port forming surface of the recording head 1. FIG.

First, in step Sll, the position of the carrier 2 is detected by the carrier home sensor 21, and the carrier 2 is moved to the home position. The details will be described later. Then, in step S12, the recovery system motor 28 is driven to operate the cap 22 so as to cover the ejection port forming surface of the recording head 1. This changes the position of the cam device 29 to the recording operation position a.
This is done by controlling from (a) to the home position (b). At this time, if the carrier 2 is accurately located at the home position, the convex part 24 will engage with the concave part 5, but if it is out of position, it will not engage, and the cap 22 will not cover the discharge port forming surface. becomes.

Next, in step S13, the carrier 2 is moved 4 steps to the left, and in step S14, the carrier 2 is moved 8 steps to the right. And in step S15,
Also, carrier 2 is moved 4 steps to the left. In other words, control is performed to swing the carrier 2 at the home position.

Due to the rocking control in steps S13 to S15, the convex portion 24 and the concave portion 5 are brought into engagement even if they are in a non-engaged state, despite the capping control in step S12. Accordingly, the cap 22 covers the ejection port forming surface of the recording head 1.

On the other hand, if the convex portion 24 and the concave portion 5 are in an engaged state in step S12, that is, if the recording head 1 and the cap 22 are in contact with each other, the cap 22 formed of an elastic material is Force (- Deforms over time, but restores itself after a predetermined time (here, about 0.3 seconds).

FIG. 8 shows details of step Sll in FIG. 7, and is a flowchart for moving the carrier to the capping position (home position).

First, in step 5101, the sensor output from the carrier sensor 21 is detected, and it is determined whether the carrier 2 is currently on the left or right side of the sensor position. Here, carrier sensor 2
As shown in FIG. 9, the level of the sensor output from the sensor 1 changes 10 steps to the right of the position where the cap 22 is applied. If the sensor output is not 1, carrier 2 is to the right of the sensor position, so in step 5102 carrier 2 is moved one step to the left, in step S1.03 the sensor output is detected, and the steps are repeated until the sensor output becomes 1. 510
2. Repeat step 8103. If the sensor output becomes 1 in step 5103, the process goes to step 5104, where it moves 5 steps to the left.

The operations in steps 8102 to 5104 are performed because if sensor detection is not performed in the same direction, backlash of the carriage drive system or the like will cause positional deviation between the right direction detection and the left direction detection. In this embodiment, since the detection is performed when the carrier 2 moves in the right direction, when the carrier 2 is on the left of the carrier sensor 21, the carrier 2 is brought to the right of the sensor position. Also, 5 of step 5104
The step size may be any amount that eliminates backlash when the moving direction of the carrier 2 changes.

Next, the process goes to step 5105, and since the sensor output is 1, it is known that carrier 2 is on the left of the sensor position, so in step 5105, carrier 2 is moved one step to the right, and in step 8106, the sensor output is detected, and the sensor Step 5105, step 8106 until the output becomes O
repeat.

If the sensor output becomes 0 in step 5106, step 5
107, move the carrier 2 to the left by 10 steps as shown in FIG. 9, and bring it to the position of the cap 22 (home position).

As described above, in this embodiment, when capping the recording head 1, the carrier 2 is swing-controlled after the capping operation, so even if the cap position is deviated due to a defect in the carrier home sensor 21 or an assembly error, etc. The convex portion 24 and the concave portion 5 engage with each other, making it possible to reliably abut the cap 22 against the recording head 1. Therefore, it is possible to prevent ejection failure that occurs when the position of the ink ejection opening of the print head 1, that is, the position of the carrier 2 on which the print head 1 is mounted, and the position of the cap 22 are misaligned.

Furthermore, since the convex portion 24 and the concave portion 5 engage with each other, the carrier 22 does not move in either the recording direction or the counter-recording direction even if an impact is applied, and the capping state can be maintained.

Furthermore, in this embodiment, suction recovery is performed after waiting for a predetermined time after capping, so that temporary deformation of the cap 22 caused by swinging of the carrier 2 while the cap 22 is in contact with the recording head 1 is restored. Empty suction will be performed later. Therefore, problems such as inability to suck ink through the cap 22 during the suction recovery process due to idle suction will not occur.

Note that in the operations of steps 813 to 315 in the above embodiment, the carrier 2 is moved left, right, left, but the same effect can be obtained even if it is moved right, left, right. In addition, in this embodiment, when carrier 2 is moved left, right, and left, the total amount of movement (the left direction is taken as a minus) is set to 0, and the final carrier position is moved to the home position. However, if the convex part 24 of the pump is in the concave part 5 of the carrier 2, the carrier 2 is mechanically fixed at the home position, so it is possible to move 4 steps on the left and 8 steps on the right or 4 steps on the right and 8 steps on the left. and career 2
The same effect as the present invention can be obtained even by moving the .

In addition, the amount of movement of the carrier is changed to 4 around the home position.
Although this is the STEP portion, it varies depending on the configuration of gears in the drive system of the carrier, and also varies depending on the load applied to the convex portion 24 of the pump and the concave portion 5 of the carrier 2. .

Furthermore, although the position of the carrier 2 is detected by the home sensor 21 in step Sll, if the position of the carrier 2 is known in advance, such as during printing, it may be moved to the home position without performing position detection. .

Further, the shape of the convex portion 24 and the concave portion 5 is not limited as long as the carrier 2 can be fixed by engaging with each other.

Furthermore, the present invention brings about excellent effects particularly in bubble jet recording apparatuses among inkjet recording apparatuses. According to this method, recording density can be increased,
This is because high definition can be achieved.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method is applicable to both so-called on-demand type and continuous type. In particular, in the case of the on-demand type, the electrothermal transducer placed in correspondence with the sheet holding the liquid (ink) and the liquid path is capable of recording information and rapidly exceeding nuclear submergence. By applying a single drive signal that causes a small temperature rise, thermal energy is generated in the electrothermal transducer, causing film boiling on the heat-active surface of the recording head.As a result, this drive signal This method is effective because bubbles in the liquid (ink) can be formed in one-to-one correspondence.The growth and contraction of the bubbles causes the liquid (ink) to be ejected through the ejection opening to form at least one drop. It is more preferable to use a pulse-shaped drive signal as this pulse-shaped drive signal, because bubble growth and contraction occur immediately and appropriately, and liquid (ink) ejection with particularly excellent responsiveness can be achieved.
U.S. Pat. No. 4,463,359, U.S. Pat. No. 4,345,26
Those described in Specification No. 2 are suitable.

Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, JP-A-59 discloses a configuration in which a slit common to a plurality of electrothermal converters is used as a discharge part of the electrothermal converters.
-123670, and JP-A No. 5, which discloses a configuration in which an opening for absorbing pressure waves of thermal energy corresponds to a discharge part.
The effects of the present invention are also effective even with a recording head configuration based on Publication No. 9-138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently.

Furthermore, a convertible chip-type recording head that is attached to the device body enables electrical connection with the device body and ink supply from the device body, or a convertible chip type recording head that is installed integrally with the recording head itself. The present invention is also effective when using a cartridge type recording head.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there are also multiple types installed to correspond to multiple inks with different recording colors and densities. It may be something that can be done.

In addition, the inkjet recording apparatus of the present invention can be used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a printer, etc., or a facsimile apparatus having a transmitting and receiving function. It may also be one that takes

〔Effect of the invention〕

As described above, according to the present invention, since capping can be performed reliably, it is possible to prevent ejection failures due to poor capping.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an embodiment of the inkjet recording apparatus of the present invention, FIG. 2 is an external perspective view of the head cartridge shown in FIG. 1, and FIG. 3 is a cap portion shown in FIG. 1. 4 is a diagram showing the operation of each part in the discharge recovery operation of the embodiment over time, FIG. 5 is a block diagram showing the control configuration of the embodiment, and FIGS. 6 to 8 are the above-mentioned controls. Flowchart showing control procedure in configuration, No. 9
The figure is a timing chart showing the operation of the above configuration. 1... Head cartridge (recording head) 2... Carrier 5... Recess 21... Carrier home sensor 22... Cap 23... Pump 24... Recess 28... Recovery motor 100. ...CPU 101...ROM 102...RAM Sega output

Claims (3)

[Claims] (1) A recording head unit that performs recording by discharging ink onto a recording medium, a cap formed to be able to cover the ejection port forming surface for discharging ink of the recording head unit, and a cap that is interlocked with the cap. and a second engaging portion formed on the recording head means to engage with the first engaging portion when the cap covers the ejection port forming surface of the recording head means. An inkjet recording apparatus comprising: a mating portion; and a drive means for swinging the recording head means after the cap covers the cap. (2) The recording head means includes a recording head that discharges ink and a carrier on which the recording head is mounted, and the second engaging portion is formed on the carrier. ). (3) The recording head means is provided with a plurality of ejection ports for ejecting ink, and is provided for each corresponding ejection port, causing a state change in the ink due to heat, and ejecting the ink from the ejection port based on the state change. and thermal energy generating means for forming flying droplets.
).