JP2749929B2 - Ink jet recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink jet recording apparatus.

[Conventional technology]

2. Description of the Related Art Conventionally, a recording apparatus that performs recording on a recording medium such as paper or an OHP sheet (hereinafter, also referred to as recording paper or simply paper) has been proposed in a form in which recording heads of various recording methods are mounted. As the recording head, there are a recording head system, a heat-sensitive system, a thermal transfer system, an ink jet system, and the like.

In particular, the ink jet recording method, which jets ink directly onto recording paper, has attracted attention as a quiet recording method with low running cost.

In a recording apparatus using such an ink jet system, a recording head having a generally arranged fine ejection port is used as a recording head. For this reason, when the recording head is not operated for a long time, for example, when the power is turned off, or when recording data is not transferred for a predetermined time or more during the recording operation, bubbles or dust are mixed into the ejection openings, or the ink solvent evaporates. In order to prevent the ink from being in an ejection failure state unsuitable for ejection and recording due to thickening or the like, capping has been performed. In this method, a cap capable of covering the ejection port forming surface of the recording head is arranged, and the ejection port forming surface is covered by the cap when the recording head is not operating.

However, the ejection failure state due to this capping, or even during the printing operation, when the ejection port not used or infrequently used due to the print pattern becomes the ejection failure state,
By refreshing the ink, a process (ejection recovery process) for removing those ejection failure factors is performed.

As one mode of means for performing such an ejection recovery process,
By driving the ink ejection energy generating element inside the ejection opening of the recording head, ink is ejected from all ejection openings toward the above-mentioned capping cap (hereinafter referred to as "preliminary ejection"), thereby eliminating ejection failure factors together with ink. Something you need to know. In general, an ink absorber is provided at a portion of the cap opposite to the ejection port in order to prevent ink leakage or rebound from the ejection port at the time of preliminary ejection.

Here, performing the above-described preliminary ejection requires a time for returning the recording head to the capping position and a driving time for the recording head. Therefore, in order to reduce the recording time, it is necessary to reduce the number of preliminary ejections. Therefore, in a conventional ink jet recording apparatus, preliminary ejection is periodically performed during recording so that the recording head does not fall into an ejection failure state. That is, the elapsed time after the previous execution of the preliminary ejection is measured by the timer, and the preliminary ejection is performed every time the elapsed time reaches a predetermined time.

At this time, when the operation is temporarily stopped during the recording operation and the above-mentioned capping occurs, conventionally, the timer is cleared, the cap is opened, and the elapsed time is measured again when the recording operation is restarted. Therefore, when the capping time is long or when the capping operation frequently occurs within the predetermined time, the preliminary ejection is not performed before the ejection failure occurs.

Also, in the above case, if the preliminary ejection is always performed when opening the cap, the ejection will not be defective, but
There has been a problem that the number of times of preliminary ejection increases.

[Problems to be solved by the invention]

In the conventional inkjet recording apparatus, as described above,
Since the timing of the preliminary ejection is determined without considering the capping time, there is a problem that ejection failure of the recording head occurs or the number of times of the preliminary ejection increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an ink jet recording apparatus capable of reducing the number of times of preliminary ejection without causing a recording head to be in an ejection failure state. And

[Means for solving the problem]

Therefore, the ink jet recording apparatus according to the invention of claim (1) is characterized in that the preliminary ejection means for performing preliminary ejection every time exceeding the predetermined time β after the previously executed preliminary ejection, and the time in which the cap is closed are set to the predetermined time β. And a preliminary ejection control means for controlling so as not to be included.

Further, the ink jet recording apparatus according to the invention of claim (2) performs a preliminary ejection every time exceeding a predetermined time β after the previously executed preliminary ejection, and when the cap closing time exceeds a predetermined time γ, the cap is closed. A preliminary discharge means for performing preliminary discharge when the cap is opened, and a preliminary discharge control means for initializing the predetermined time β when the cap is opened when the cap is closed for a predetermined time γ. .

[Operation] According to the ink jet recording apparatus of the first aspect of the present invention, the time during which the cap is closed is controlled not to be included in the predetermined time β. In addition, the number of times of performing the preliminary ejection can be reduced.

According to the ink jet recording apparatus of the present invention, when the cap is opened for a time exceeding the predetermined time γ, when the cap is opened, the pre-ejection means is driven to perform the pre-ejection. Since the predetermined time β is initialized, it is possible to prevent the recording head from falling into an ejection failure state even if the capping period of the recording head is prolonged during the recording operation.

〔Example〕

Hereinafter, embodiments of the inkjet recording apparatus of the present invention will be described with reference to the drawings.

FIGS. 1A and 1B show an example of an external configuration of an embodiment when the present invention is applied to a document processing apparatus.

Here, reference numeral 1 denotes a keyboard unit, in which a key group 2 such as keys for inputting characters such as characters and numerals and a control key are arranged. It can be folded as shown. Reference numeral 4 denotes a paper feed tray for feeding a sheet-shaped recording medium to the printer unit 8 in the apparatus, which is stored so as to cover the printer unit 8 as shown in FIG. Reference numeral 5 denotes a feed knob for manually setting and ejecting the recording medium, 6 a display for displaying input text and the like, and 7 a handle used for transporting the apparatus according to the present embodiment. .

FIG. 2 shows a configuration example of the printer unit 8 according to the present embodiment.

Here, reference numeral 9 denotes a head cartridge having an ink jet recording head which will be described in detail with reference to FIGS.
Is a carriage for mounting the scanner and scanning in the S direction in the figure. Reference numeral 13 denotes a hook for attaching the head cartridge 9 to the carriage 11, and reference numeral 15 denotes a lever for operating the hook 13. The lever 15 is provided with a marker 17 for indicating a scale provided on a cover, which will be described later, so as to be able to read a print position, a set position, and the like of the recording head of the head cartridge. Reference numeral 19 denotes a support plate for supporting an electrical connection to the head cartridge 9. Reference numeral 21 denotes a flexible cable for connecting the electrical connection unit and the main body control unit.

23 is a guide shaft for guiding the carriage 11 in the S direction, and is inserted into a bearing 25 of the carriage 11. 27
Is a timing belt to which the carriage 11 is fixed and which transmits power for moving the carriage 11 in the S direction, and is stretched over pulleys 29A and 29B arranged on both sides of the apparatus. A driving force is transmitted to one pulley 29B from a carriage motor 31 via a transmission mechanism such as a gear.

Reference numeral 33 denotes a platen roller for regulating a recording surface of a recording medium such as paper (hereinafter, also referred to as recording paper) and transporting the recording medium during recording or the like. 37 is a paper pan for guiding the recording medium to the recording position from the paper feed tray 4 side, and 39 is disposed in the middle of the recording medium feeding path, presses the recording medium toward the platen roller 33, and conveys it. For the feed roller. 41 is disposed downstream from the recording position on the recording medium transport direction,
A discharge roller for discharging the recording medium toward a discharge port (not shown). Reference numeral 42 denotes a spur provided corresponding to the paper discharge roller 41, which presses the roller 41 via the recording medium to generate a conveyance force of the recording medium by the paper discharge roller 41. Reference numeral 43 denotes a feed roller 39 and a holding plate 4 for setting a recording medium.
5. Release lever for releasing the bias of each spur 42.

Reference numeral 45 denotes a pressing plate for suppressing the floating of the recording medium in the vicinity of the recording position and ensuring the state of close contact with the platen roller 33. In this embodiment, an ink jet recording head that performs recording by performing ink ejection as a recording head is employed. Therefore, the distance between the ink ejection port forming surface of the recording head and the recording surface of the recording medium is relatively small, and the interval must be strictly controlled to avoid contact between the recording medium and the ejection port forming surface. Therefore, the arrangement of the holding plate 45 is effective. Reference numeral 47 denotes a scale provided on the holding plate 45, and reference numeral 49 denotes a marker provided on the carriage 11 in correspondence with the scale, and the print position and the set position of the recording head can also be read by these.

Reference numeral 51 denotes a cap formed of an elastic material such as rubber which faces the ink ejection port forming surface of the recording head in the home position, and is supported so as to be able to contact / separate from the recording head. The cap 51 is used for protection of a recording head at the time of non-recording or the like and for recovery processing of the recording head ejection. The ejection recovery process is a process in which ink is ejected from all ejection ports by driving an energy generating element provided inside the ink ejection ports and used for ink ejection, thereby recording air bubbles, dust, and thickening. Processing to remove the cause of ejection failure such as ink that is no longer suitable for printing (preliminary ejection)
Alternatively, this is a process for removing the cause of the discharge failure by forcibly discharging the ink from the discharge port.

Reference numeral 53 denotes a pump used for applying a suction force for forcibly discharging the ink and for sucking the ink received by the cap 51 at the time of the discharge recovery processing by the forced discharge and the discharge recovery processing by the preliminary discharge. Reference numeral 55 denotes a waste ink tank for storing the waste ink sucked by the pump 53, and reference numeral 57 denotes a tube connecting the pump 53 and the waste ink tank 55.

Reference numeral 59 denotes a blade for wiping the ejection head forming surface of the recording head, which is located at a position for projecting toward the recording head to perform wiping in the process of moving the head and a retreating position not engaging with the ejection port formation surface. It is movably supported. Reference numeral 61 denotes a recovery motor, and reference numeral 63 denotes a cam device for receiving power transmitted from the recovery motor 61 to drive the pump 53 and move the cap 51 and the plate 59, respectively.

Next, the details of the above-described head cartridge 9 will be described.

FIG. 3 is an external perspective view of a head cartridge 9 in which a discharge unit 9a and an ink tank 9b forming an ink jet recording head main body are integrated. In the figure, 906e is
The hook is hooked by a hook 13 provided on the carriage 11 when the head cartridge 9 is mounted. As can be seen, the pawl 906e is located inside the full extension of the recording head. Further, in the vicinity of the front discharge unit 9a of the head cartridge 9, a positioning abutting portion (not shown) is provided. 906f is Carriage 11
The head opening is provided with a support board for supporting a flexible board (electric connection part) and a rubber pad.

FIGS. 4 (A) and (B) are exploded perspective views of the head cartridge shown in FIG. 3, which is a disposable type in which an ink supply unit as an ink supply source is integrated as described above. is there.

In FIG. 9A, reference numeral 911 denotes a heater board in which an electrothermal conversion element (ejection heater) and a wiring such as Al for supplying electric power are formed on a Si substrate by a film forming technique. Reference numeral 921 denotes a wiring board for the heater board 911, and the corresponding wiring is connected by, for example, wire bonding.

Reference numeral 940 denotes a top plate provided with a partition for defining an ink flow path, a common liquid chamber, and the like. In the present embodiment, the top plate is made of a resin material having an orifice plate unit integrally.

930 is, for example, a metal support, 950 is a holding spring,
The heater board 911 and the top board 940 are sandwiched between them so that they are engaged with each other, so that the heater board 910 and the top board 940 are pressed and fixed by the urging force of the pressing spring 950. Note that the support 930 may be provided with a wiring board 921 attached thereto or the like, and may have a positioning reference to the carriage 11 that scans the head. In addition, the support 930 also functions as a member that radiates and cools the heat of the heater board 911 generated by driving.

Reference numeral 960 denotes a supply tank, which functions as a sub-tank that receives ink supply from the ink storage unit 9b serving as an ink supply source and guides ink to a common liquid chamber formed by joining the heater board 911 and the top plate 940. Reference numeral 970 denotes a filter disposed at a position in the supply tank 960 near the ink supply port to the common liquid chamber, and 980 denotes a cover member of the supply tank 960.

900 is an absorber for impregnating the ink, and is arranged in the ink tank main body 9b. 1200 is the above parts 911-9
A supply port for supplying ink to the recording element 9a composed of 80, and the unit is connected to the ink tank main body.
By injecting ink from the supply port 1200 in a step before the arrangement in the portion 1010 of 9b, the ink impregnation of the absorber 900 can be performed.

Reference numeral 1100 denotes a lid member of the cartridge body, and 1400 denotes an atmosphere communication port provided in the lid member for communicating the inside of the cartridge with the atmosphere. Reference numeral 1300 denotes a liquid-repellent material disposed inside the air communication port 1400, thereby preventing ink from leaking from the air communication port 1400.

When the ink filling into the ink tank 9b through the supply port 1200 is completed, the discharge unit 9a including the parts 911 to 980 is positioned and arranged in the portion 1010. The positioning or fixing at this time is performed, for example, by using a projection 10 provided on the ink tank body 9b.
12 and a hole 931 correspondingly provided in the support 930, whereby the head cartridge 9 shown in FIG. 4 (B) is completed.

And the ink is supplied from the inside of the cartridge to the supply port 1200,
The supply tank 960 is provided through a hole 932 provided in the support 930 and an introduction port provided on the back surface side of the supply tank 960 in FIG. 4 (A).
After passing through the inside, the liquid flows from the outlet through an appropriate supply pipe and the ink inlet 942 of the top plate 940 into the common liquid chamber. A packing made of, for example, silicone rubber or butyl rubber is provided at the above-mentioned connection portion for common use of ink, whereby sealing is performed and an ink supply path is secured.

Since the detachable operation mechanism including the operation lever 15 and the hook 13 is provided on the side of the carriage 11, that is, on the movement direction side of the carriage 11, the detachable operation mechanism does not form a large dead space due to the movement of the carriage.

Next, an abutment portion for positioning at the time of mounting the head cartridge will be described.

Reference numeral 601a denotes an abutting portion for positioning in the left-right direction, and is provided at two locations on the side of the abutting member 607. For positioning in the left-right direction, an abutting portion 601f provided on the support plate 606 is used in addition to the abutting portion 601a.

601b is a butting portion for positioning in the front-rear direction,
It is formed on the lower side of the abutting member 607.

601c is a butting portion for vertical positioning,
2 of the lower side of the butting member 607 and the lower side of the support plate
Formed at two places.

FIGS. 5A and 5B show the carriage 11 respectively.
3A and 3B are a top view and a left side view showing a state when the head cartridge 9 is mounted on the vehicle.

In these figures, reference numeral 906a denotes an abutting portion provided on the head cartridge 9 so as to be able to abut against the abutting portion of the carriage 11 when the recording head is mounted, and 906b and 906c.
Are contact portions corresponding to the contact portions 601b and 601c, respectively.

Here, with reference to FIG. 5 (A), an outline of the engagement relationship of each part when the recording head is mounted will be outlined.

The contact portion 906a of the head cartridge 9 is in contact with the abutment portion 601a of the carrier 6, and at the same time, the pawl 906 of the head cartridge 9 is in contact with the coil spring 610 via the hook 13 hooked to this. The force is applied to the left in the figure by the urging force. As a result, the head cartridge 9 receives a moment force centered on the contact portion. At this time, the substrate 906d provided on the head comes into contact with the abutting portion 601f, and as a result, the head cartridge 9 is positioned in the left-right direction, and the position is maintained.

At this time, the protrusion 605A of the rubber pad 605 is
Is compressed and deformed by contact with With this deformation,
A force for pressing the terminal pad of the flexible substrate 904 and the terminal of the substrate 906d is generated. In this case, since the substrate 906d is in contact with the abutting portion 601f, the amount of deformation of the protruding portion 605A is constant, and the above-described stable pressing force can be obtained.

It should be noted that FIG. 7 does not show a state in which the protrusion 605A is compressed and deformed.

The positioning of the head cartridge 9 in the front-back and up-down directions is performed during the mounting process.

6 and 7 are a side view and a top view, respectively, showing the mechanism around the head cartridge shown in FIG. 2 and the like.

In these figures, reference numeral 91 denotes a roller rotatably supported at the front end of the carriage 11. The roller 91 is provided so that a part thereof protrudes forward from the discharge port surface of the head cartridge, and comes into contact with the paper holding plate 45 and rotates thereon. Reference numeral 613 denotes a roller spring provided at the rear end of the carriage 11. Roller spring 613, roller 613
A, connecting member 613B that supports roller 613A, and connecting member 6
It is composed of a spring 613C that urges 13B in a predetermined rotation direction. The roller 613A abuts a front end plate 105 erected at the front end of the bottom plate 100 of the apparatus so as to extend in parallel with the above-described guide shaft, and rotates thereon. Connecting member 613B is Carriage 11
Is rotatably supported by a predetermined shaft 113, and the spring 6
13C is a connecting member 613 supported by a predetermined shaft of the carriage 11.
A bias is applied to rotate B counterclockwise about axis 113. With the configuration of the roller spring 613 described above, the carriage 11 is always urged toward the paper holding plate 45.

Reference numeral 25 denotes a bearing that engages with the guide shaft 23, and is mounted on both side ends of the carriage 11. The bearing 25 has an eccentric bearing portion with respect to a case related to its mounting, and the two bearings 25 are mounted so that their eccentric directions are opposite to each other.
The bearing 25 on the side shown in FIG. 6 is provided so as to be swingable about a boss 112 provided on the carriage 11 as an axis. That is, the portion of the carriage 11 where the bearing 25 is mounted is a long hole, and the two projections 25A of the bearing 25 are restricted by the boss 112 from moving in the front-rear direction (the left-right direction in FIG. 6). You. As a result, the bearing 25 swings relative to the carriage 11 in accordance with the movement of the carriage 11. At this time, in the movement of the bearing 25 in the direction of the guide shaft 23, the projection 25B provided on the bearing 25 is restricted by a part of the carriage 11.

FIG. 8 is an exploded perspective view of a main part of the recovery device including the cap 51, the pump 53, the blade 59, the motor 61, the cam device 63 and the like in FIG.

Here, 501 is an ink absorber arranged inside the cap 51, 503 is a holding member for holding the cap 51, and 505 is a pin.
This is a cap lever that is rotatably mounted around the 507 and that causes the cap 51 to abut / remove the discharge port forming surface of the discharge unit 9a by the force applied to the pin 507. 51
Reference numeral 1 denotes a pin that is engaged with the end portion 509 of the catch lever 505 to regulate the rotation range of the catch lever 505.

Reference numeral 513 denotes a jig having a hole into which the pin 507 of the catch bar 505 is fitted, and is used to attach the catch bar 505 to a support 515 provided on the pump 53. Reference numeral 516 denotes a fastening member for securing the attached state. Reference numeral 517 denotes an action portion which acts on the cap 51 to apply a force for bringing the cap 51 into contact with the discharge port forming surface, and is engaged with substantially the center of the rear side of the cap 51. The action section has a suction port 517A for sucked ink, and ink flow paths are formed in the inside of the jet lever 505, the pins 507, the jig 513, and the support section 515, respectively. Then, when the pump 53 exerts a suction force, ink flows through these flow paths as shown by arrows in the drawing.
Introduced within.

Reference numeral 519 denotes a shaft protruding from the center of the end face of the pump 53. The pump 53 itself can rotate around the shaft 519. This turning force is applied to the cap lever 505 via the support portion 515, and the cap 51 moves forward and backward accordingly. Joint
521 is coupled to a member 523 to which the tube 57 is attached.
An ink flow path is formed inside the shaft 519, the joint 521, and the member 523, and the ink sucked by the pump 53 flows through the flow path 57 through the flow path as indicated by an arrow in the drawing.
Through the waste ink tank 55.

525 is a piston of the pump 53, 527 is its shaft, 529 is a packing, and 531 is a cap of the pump 53. A pin 533 is attached to the piston shaft 527 and receives a force for operating the piston 525.

Reference numeral 535 denotes a blade lever to which the blade 59 is attached. The blade lever 535 is rotatably supported around a shaft protruding from an end face of the pump 53, and causes the blade 59 to protrude or retreat toward the recording head with the rotation. Reference numeral 537 denotes a spring that applies a rotating force to the blade lever 535 in a direction in which the blade 59 projects. Also, 539 is a cap 53 for the pump 53 itself.
Is a spring that gives a rotation behavior in the direction toward the recording head.

A gear train 541 transmits the rotation of the motor 61 to the cam device 63. The cam device 63 includes a cam 547 for engaging and rotating an engaging portion 545 provided on the pump 53, and a pump 53.
A cam 549 for engaging the pin 533 provided on the piston shaft 527 to operate the pump, and a cam 553 for engaging and rotating the engaging portion 551 provided on the blade lever 535.
And a cam 557 that engages with a switch 555 for detecting the home position of the cam device 63. The operation of these cams will be described later.

 FIG. 9 is a sectional view showing the structure of the cap 51 and the like.

Here, in the present embodiment, the ink suction port 61 in the cap is used.
Is opened in the lower part in the vertical direction, and the ink flow path 5 is directed toward the ink introduction port 517A provided in the action portion 517 of the pump lever 505.
63 are formed. Further, the suction port 561 is not completely covered by the absorber 501.

According to this configuration, even if the ink ejected in the ejection recovery process or the like flows downward due to gravity, the ink is sucked from the suction port 561 provided below, so that the ink absorber 501
The amount of ink remaining in the ink becomes extremely small. Therefore, the life of the ink absorber or the cap 51 to which the ink absorber is attached can be extended by greatly delaying deterioration due to solidification.

FIG. 10 and FIG. 11 are explanatory views showing the contour curves of the respective cams of the cam device 63 and the operation positions of the respective parts corresponding to the respective cam positions. The numerical values in FIG. 10 are the cam rotation angles.

In these figures, (a) shows the cam position and the state of each part when performing the recording operation. The cap 51 and the blade 59 are separated from the discharge port forming surface of the recording head, and the pump
53 is at top dead center. (B) is a home position switch
55 is the off position, and this position is the home position of the cam device 63.

This is a position set when recording is in a standby state or the like. At this time, the cap 51 covers the discharge port forming surface and the blade 59
Is retracted, and the pump 53 is also at the top dead center.

When the cam is rotated from the position (b), the cap 51
The piston 525 moves toward the bottom dead center while being joined (cap-on) to the discharge port forming surface, and the negative pressure of the suction system reaching the cap increases. Eventually, after the piston 525 reaches the ink inlet of the pump and closes it (the period during which the valve closes), the valve starts to open (point 109.5 °), opens completely (point 130.5 °), Then piston 525
Reaches the position (c) near the bottom dead center. In consideration of the fluid resistance of the ink suction system, sufficient rotation is performed by stopping rotation of the cam at this position for a predetermined time, and then rotating the cam again, the piston 525 reaches the bottom dead center and the cap is closed. Five
1 starts to separate from the discharge port forming surface. This position (d) is held for a predetermined time.

Then, when the cam is further rotated, the piston 525 starts to move toward the top dead center again. In this process, the valve starts to close (209.
5 ° point), then completely occluded point (230.5 ° point)
On the other hand, at the position (e), the cap 51 is completely separated from the discharge port forming surface. By driving the piston 525 several times in this vicinity, the ink remaining in the ink suction system is sucked (empty suction) toward the pump. The left and right spaces of the piston 525 in the pump are:
The flow path is communicated with a flow path (not shown). The flow path is closed when the piston moves from top dead center to bottom dead center, and is opened when the piston moves from bottom dead center to top dead center. The space on the right side of the piston communicates with a flow path provided on the pump shaft 519. Therefore,
In the process of idle suction, when the piston 525 moves from bottom dead center to top dead center, 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 525 moves from top dead center to bottom dead center, the ink suction system , Ink is introduced into the left space, and ink is discharged from the right space to the waste ink tank.

Thereafter, when the cam is further rotated in the forward direction, the blade 59 protrudes to be ready for wiping 8 (position (f)). When the carriage 11 is moved to the recording area side in this state, the blade 59 is engaged with the ejection port forming surface of the head and the surface thereof is wiped, and the ink and the like attached to the ejection port forming surface are wiped. Then, the cam is further rotated to retract the blade 55 and set the cam at the position (a). In this state, the carriage 11 is moved to the cap side, and the discharge port forming surface of the head is opposed to the cap 51, and then the cam is moved to the position (b) to be the cap-on and stopped.

When shifting from the standby state to recording, the cam may be rotated in the positive or negative direction from the position (b) to protrude the blade 59, and wiping may be performed before recording.

Next, a control configuration for controlling each unit of the document processing apparatus configured as described above will be described with reference to FIG.

In FIG. 1, reference numeral 10 denotes characters processed from the keyboard 1 and displayed on the display 6 or
Is a control unit that operates the printer unit 8 based on a recording instruction from the printer. The control unit 10 includes an MPU 1000 that executes various control procedures, and a ROM 100 that stores the above control procedures and data.
1, R used for work area etc. in the above control execution
It comprises an AM 1002, a CG 1003 that stores character patterns such as characters input from the keyboard unit 1, and an interface unit 1004 that connects to external devices such as the keyboard unit 1. The control unit 10 and the printer unit 8 are electrically connected by a signal line 1005.

The printer unit 8 has a printer control unit 80 that controls the head 9 and the like in order to reduce the load on the control unit 10. The printer control unit 80 has substantially the same configuration as the control unit 10, and measures an MPU 800, a ROM 801, a RAM 802, and time.
It comprises a TW timer 803, a TO timer 804, a TC timer 805, and an interface unit 806.

The printer control unit 80 of the printer unit 8 controls the head 9, the carriage motor 31, and the transport motor.
35 and a recovery motor 61, which are driven by a head driver 9A and motor drivers 31A, 35A, 61A, respectively. These motors 31, 35 and 61 have a DC motor configuration, and the rotation direction is controlled by the polarity of the drive pulse. Further, based on the detection of the recovery system home sensor 65 and the carriage home sensor 67, the printer control unit 80 can recognize the cap position and the movement position of the carriage 11.

In the above control configuration, when a document creation process is performed and a print start command is issued by pressing a print key (not shown) of the keyboard unit 1, the MPU 1000 of the control unit 10 refers to the CG 1003 for a document such as an input character. And convert it to print data. The MPU 1000 adds a control command to the converted print data, and transfers the control data to the printer control unit 80 via the interface unit 1004 and the signal line 1005. Upon receiving the transfer data, the MPU 800 of the printer control unit 80 controls the head 9 and executes printing while interpreting the control commands added to the print data based on the command table stored in the ROM 801.

FIG. 13 shows a table of the above-described control commands stored in the ROM 801 of the printer control unit 80. In the figure, C1
Is a print start command indicating the start of printing, and C2 is a print end command indicating the end of printing. When data includes a plurality of pages, it means that the printing of the last page is completed. C3 is a data transfer command indicating that print data is transferred by the number indicated by the next data to be transferred.

FIG. 14 is a diagram showing a data format transferred from the control unit 10 to the printer control unit 80. First, a print start command D1 is transferred, a data transfer command D2, a transfer data number (N) D3, N pieces of data D4, and a print end command.
D5 is transferred.

Next, the flow chart and timing chart shown in FIG. 15 and FIG. 16 respectively show the control procedure for the printer control section 80 receiving the transfer data from the control section 10 to perform the preliminary ejection and opening / closing of the cap as described above. It will be described with reference to FIG.

The control procedure of FIG. 15 is started when the power of the printer unit 8 is turned on and a predetermined initialization operation is completed.

First, the MPU 800 receives data from the control unit 10 in step S1, and determines whether or not there is transfer data. If no data has arrived, it is determined in step S2 whether the cap 51 is open. This is because the MPU800 itself is a cap
Since the opening and closing of 51 is controlled, it can be easily determined.
If the cap 51 is closed, the process returns to step S1, and if the cap 51 is open, it is determined in step S3 whether a data wait timer (hereinafter, referred to as a TW timer) 803 has been started. The TW timer is a timer that counts time when data from the control unit 10 is not sent, and is used to obtain a timing for closing the cap 51. If the TW timer 803 has not been started, it starts at step S4 and goes to step S5, and if it has been started, it goes to step S5. Step
In S5, the TW timer 803 determines whether a predetermined time α seconds has elapsed.

Explaining this predetermined time α seconds, keeping the cap 51 of the recording head open will hinder the ejection of ink droplets, so when the transfer data from the control unit 10 is interrupted, the cap 51 is Just close it. However, if the cap 51 is immediately closed by saying that no data comes, the time required for recording will be longer than the time required for opening and closing the cap 51. Therefore, a time α seconds that does not hinder the ejection of ink droplets is provided, and the cap 51 is closed if no data arrives for more than α seconds.

Next, if a negative determination is made in step S5, the process returns to step S1. On the other hand, if it is determined that α seconds have elapsed, the cap 51 is closed in step S6, and the TW timer 803 that does not need to be counted because the cap 51 is closed in step S7 is initialized (cleared) and stopped.

The operation of closing the cap 51 described above is described in FIGS.
In the figure, the recovery system motor is set so that the position of the cam device 63 changes from the recording operation position (a) to the home position position (b).
This is done by driving 61. The operation of opening the cap 51, which will be described later, is performed by driving the recovery motor 61 so that the position of the cam device 63 changes from the home position (b) to the recording operation position (a).

Next, in step S8, a cap open timer (hereinafter referred to as a TO timer) 804 is temporarily stopped. TO timer 8
04 is a timer that counts the time that the cap 51 has been open since the previous preliminary discharge was performed, and is used to obtain the timing of the preliminary discharge. Then, in step S9, a cap-close timer (hereinafter referred to as TC timer) 805 is started, and the process returns to step S1. The TC timer 805 is a timer that counts the time during which the cap 51 is closed, and is used to determine whether or not to perform preliminary ejection when the cap 51 is opened.

If the transfer data has been received in step S1, the TW timer 803 is initialized (cleared) in step S10. Next, in step S11, it is determined whether or not the cap 51 is open. If the cap 51 is closed, it is determined in step S12 whether the TC timer 805 has passed a predetermined time γ seconds or more. If the determination is negative, the cap is opened in step S18, and the TC timer 805 is initialized and stopped in step S19. Then, the TO timer 804 is started, and step S25 is performed.
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However, if the predetermined time γ seconds or more has elapsed in step S12, the cap 51 is opened in step S13, and in step S14,
Initializes and stops the TC timer 805. Then, the TO timer 804 is initialized in step S15, preliminary discharge is performed in step S16, and the TO timer 804 is started in step S17.
Go to step S25.

Next, if the cap 51 is open in step S11, it is determined in step S21 whether the TO timer 804 has passed a predetermined time β seconds or more. If not more than β seconds, go to step S25. On the other hand, if it has passed, step S22
To initialize the TO timer 804, perform preliminary ejection in step S23, start the TO timer 804 in step S24, and go to step S25. In step S25, a process (operation relating to printing since it is a printer) is performed in accordance with the data received in step S1, and the process returns to step S1 to receive new transfer data.

In the timing chart of FIG. 16 showing the operation according to the above control procedure, (a) shows the timing of the data transferred from the control unit 10. The data transfer is interrupted because the control unit 10 may take time to convert the data into print data. (B) to (d) show measurement times of the TW timer 803, the TO timer 804, and the TC timer 805, respectively. The predetermined times α, β, and γ are set to 5, 30, and 6 seconds, respectively. (E) shows the timing of opening and closing the cap 51, and (f) shows the timing of preliminary discharge.

Upon receiving the transfer data at time t _0, step S
Open cap 51 at 1, S10, S11, S12, S18 and go to step S
At 20, the TO timer 804 is started. Hereafter, step S
1, S10, S11, S21, S25 are repeated, but the TO timer 804 sets the time t ₁
When 30 seconds (β) are reached, steps S22 to S24 are executed to perform preliminary ejection, and the TO timer 804 is cleared and started.

In time t _2, the the transfer data can not come to start the TW timer 803 at step S1, S2, S3, S4. When TW timer 803 at time t ₃ reaches 5 seconds (gamma), to close the cap 51 by running the step S6, further at step S7 to S9, clear TW timer 803-Sutotsupu, of course measures the TO timer 804 Stop in 20 seconds, start TC timer 805. Accordingly, the TO timer 804 interrupts the measurement during the period in which the cap 51 is closed, so that the predetermined time β does not include the period in which the cap is closed.

When the transfer data arrives at time t _4, step S1, S10, S
The process proceeds to steps S11 and S12. At this time, since the TC timer 805 is smaller than γ (30), steps S18 to S20 are executed. Accordingly, the cap 51 is opened, the TC timer 805 starts clearing, and the TO timer 804 starts 20 seconds during the measurement. For this reason,
Run the step S21, S22, S23, S24 at time t ₅ after 10 seconds from the time of opening the cap 51, the preliminary ejection is performed.

Transfer data at time t ₆ is no longer coming, this state is 5
Seconds (α) at time t ₇ and continues cap 51 is closed. Here, the period during which no transfer data arrives is long,
Timer 805 is to transfer data has arrived at a time t ₈ became 80 seconds. In this case, the process proceeds to steps S1, S10, S11 and S12, but since the TC timer 805 is larger than γ (60), steps S13 to S17 are executed. Therefore, cap 51 opens and TC
Timer 805 clears and stops. In addition, TO timer 8
After clear stop of 04, preliminary ejection is performed,
The TO timer 804 starts. Thus, Cap 51
If the closed period exceeds 60 seconds (γ), the preliminary ejection is performed when the cap 51 is opened, so that it is possible to prevent the ejection failure state.

Then, at time t _9, the TO timer 804 reaches 30 seconds,
Since the steps S1, S10, S11, S21 to S25 are executed, the preliminary ejection is performed.

As described above, in this embodiment, while the cap 51 is closed, the TO timer 804 is stopped in step S8, and when the cap 51 is opened, the TO timer 804 is started in step S20. , The number of times of preliminary ejection can be reduced without causing the ejection failure. Therefore, the delay of the recording time required for the preliminary ejection can be reduced.

In addition, the time when the cap 51 is closed is determined by the TC timer 805.
When the time is longer than the predetermined time γ, the preliminary ejection is performed in step S16 when the cap 51 is opened. Therefore, even if the capping period of the recording head during recording is prolonged, It is possible to prevent the recording head from causing an ejection failure.

In the above-described embodiment, the control unit 10 transfers the recording data to the printer control unit 80 of the printer unit 8, and the printer control unit 80
Although 80 controls recording by controlling the head 9 and the like, the controller 10 may directly control the printer 8.

Further, the present invention brings about an excellent effect particularly in a bubble jet type recording apparatus among ink jet recording apparatuses. This is because according to such a method, it is possible to attain higher recording density and higher definition.

Regarding the typical configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to any of a so-called on-demand type and a continuous type. In particular, in the case of the on-demand type, the electrothermal converter disposed corresponding to the sheet or the liquid path holding the liquid (ink) has a rapid response exceeding the nucleate boiling corresponding to the recorded information. By applying at least one drive signal that gives rise to a temperature rise, heat energy is generated in the electrothermal transducer, causing film boiling on the heat-acting surface of the recording head. As a result, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed, which is effective. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. U.S. Pat. No. 44
Those described in 63359 and 43435262 are suitable. Further, when the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As a configuration of the recording head, in addition to a combination configuration of a discharge port, a liquid path, and an electrothermal converter (a linear liquid path or a right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, a heat acting section The present invention includes the achievement using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region. In addition, Japanese Patent Application Laid-Open No. 59-123670 discloses a configuration in which a slit common to a plurality of electrothermal transducers is used as a discharge portion of the electrothermal transducer, and an aperture for absorbing a pressure liquid of heat energy is provided. The effect of the present invention is effective even when a recording head configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit.
That is, whatever the form of the recording head is, the recording can be performed reliably and efficiently.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by combining a plurality of recording heads, or a configuration as a single recording head that is integrally formed. In addition, even in the case of the serial type as in the above-described embodiment, a convertible chip-type recording that can be electrically connected to the apparatus main body or supplied with ink from the measure main body by being attached to the apparatus main body. The present invention is also effective when a cartridge-type recording head provided integrally with the head or the recording head itself is used.

Regarding the type or number of recording heads to be mounted, for example, only one recording head is provided corresponding to a single color ink, and a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities. May be used.

In addition, the form of the inkjet recording apparatus of the present invention may be a form used for an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmission / reception function. It may be something.

〔The invention's effect〕

As described above, according to the present invention, the number of preliminary ejections can be reduced without causing the recording head to be in a defective ejection state by performing the preliminary ejection in consideration of the closing time of the cap. Thus, the recording time can be reduced.

[Brief description of the drawings]

1A and 1B are external perspective views of an embodiment in which the present invention is applied to a document processing apparatus during use and storage, and FIG. 2 shows an example of a configuration of a printer applicable to the present invention. 3 is an external perspective view of the head cartridge shown in FIG. 2, and FIGS. 4A and 4B are an exploded perspective view and an external perspective view of the head cartridge shown in FIG. FIGS. 5 (A) and 5 (B) are a top view and a side view showing a state where the head cartridge is mounted on the carriage. FIGS. 6 and 7 are other than the carriage shown in FIG. 2 and the like. FIG. 8 is an exploded perspective view of the ejection recovery mechanism shown in FIG. 2, FIG. 9 is a side sectional view of a cap portion of the above-described mechanism, FIG. 10 is a timing chart showing a series of recovery operations in the above mechanism. 11, FIG. 11 is a diagram showing the operation of each part in the ejection recovery operation of the above mechanism in time sequence, FIG. 12 is a block diagram showing a control configuration in the printing apparatus shown in FIG. 2, etc., and FIG. A command table showing commands used in the configuration, FIG. 14 is a data format transferred in the above-described control configuration, FIG. 15 is a flowchart showing a control procedure in the above-described control configuration, and FIG. 16 shows an operation in the above-described configuration. This is a timing chart. DESCRIPTION OF SYMBOLS 1 ... Keyboard part 2 ... Key group 6 ... Display unit 8 ... Printer part 9 ... Head cartridge 10 ... Control part 11 ... Carriage 31 ... Carriage motor 35 ... Carrier motor 51 ... Cap 53 … Pump 61… Recovery motor 63… Cam device 69… Paper sensor 80… Printer controller 501… Absorber 561… Suction port

Claims (4)

(57) [Claims] 1. An ink jet recording apparatus which performs recording using a recording head which discharges ink from a discharge port on a recording medium, wherein the recording head is opened and closed with respect to a discharge port forming surface of the recording head. A cap formed so as to be coverable; a cap driving unit that opens the cap at the start of driving of the recording head and closes when the non-driving period of the recording head exceeds a predetermined time α; and discharges ink from a discharge port of the recording head. Means for performing a preliminary discharge, a preliminary discharge means for performing a preliminary discharge every time exceeding a predetermined time β after the previously executed preliminary discharge, and a preliminary discharge for controlling the time during which the cap is closed not to be included in the predetermined time β. An ink jet recording apparatus comprising: a control unit. 2. An ink jet recording apparatus which performs recording using a recording head which discharges ink from a discharge port onto a recording medium, wherein the recording head is opened and closed with respect to a discharge port forming surface of the recording head. A cap formed so as to be coverable; a cap driving unit that opens the cap at the start of driving of the recording head and closes when the non-driving period of the recording head exceeds a predetermined time α; and discharges ink from a discharge port of the recording head. Means for performing a preliminary discharge, wherein a preliminary discharge is performed every time a predetermined time β has elapsed since the last preliminary discharge executed, and when the time during which the cap is closed exceeds a predetermined time γ, the cap driving means opens the cap. Preliminary discharge means for performing preliminary discharge, and when the time during which the cap is closed exceeds the predetermined time γ, the cap driving means Inkujietsuto recording apparatus characterized by said predetermined time β has and a preliminary discharge control means for initializing when opening the cap. 3. The ink jet recording apparatus according to claim 2, wherein said preliminary ejection control means controls so that a time during which said cap is closed is not included in said predetermined time β. 4. The recording head is provided for each of a plurality of ejection ports for ejecting ink and a corresponding ejection port, and causes a state change due to heat in the ink to cause the ink to flow from the ejection port based on the state change. The ink jet recording apparatus according to any one of claims 1 to 3, further comprising: thermal energy generating means for forming flying droplets by discharging.