JP2001001511A - Ink jet imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet imaging apparatus in which a print head is protected against damage. SOLUTION: When a decision is made by an ink tank sensor 48 that an ink tank is not loaded to a print head, a general control section 40 controls a recovery operation control section 42 or a head control section 44 not to suck or eject ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type image forming apparatus for forming an image on a recording medium by discharging ink from nozzles formed on a print head.

[0002]

2. Description of the Related Art As one of output devices of computers and workstations, there is known an ink jet type image forming apparatus which forms an image on a recording medium such as recording paper by discharging ink. The inkjet type image forming apparatus generally includes a print head having nozzles for discharging ink, a carriage mounted with the print head and reciprocating in a predetermined direction, and a direction orthogonal to the predetermined direction (recording medium conveyance). And a recording medium transport device that transports the recording medium in the direction (i.e., direction).

When an image is formed on a recording sheet, the recording sheet being conveyed by the recording medium conveying device is temporarily stopped, and the carriage is reciprocated in the above-mentioned predetermined direction to generate an image signal carrying image information. Discharging ink from the nozzle based on the
An image for one band is formed on a portion of the recording paper which is located in an image forming area facing an outlet (ink ejection port) of a nozzle. Thereafter, the paper is conveyed by the width of one band and stopped, and ink is ejected from the nozzles based on the image signal while the carriage is reciprocated again in the above-mentioned predetermined direction. Then, an image is formed in a newly located portion. By repeating such an operation, an image is formed on the recording paper.

In an image forming apparatus that discharges ink, such as the above-described ink jet type image forming apparatus, when an image is continuously formed (printed), the ink discharge state of the nozzles may change and the image quality may deteriorate. There is. The reason why the ink ejection state from the nozzle changes is that bubbles are generated in the nozzle or foreign matter (for example, paper powder) is mixed therein. Therefore, in order to remove bubbles, foreign matter, and the like in the nozzle, a recovery device that forcibly sucks ink from the nozzle and recovers an ink discharge state from the nozzle to an initial state is used. This recovery device is used for determining the ink ejection state during printing or at predetermined time intervals for printing.

In the recovery device, the outlet of the nozzle formed in the print head is covered with a cap made of rubber (capping), and a negative pressure is generated from the outside to suck ink from the nozzle to clean the inside of the nozzle. As a result, the ink ejection state from the nozzle is restored to the initial normal ejection state.

[0006]

The above-described print head has an ink tank for storing ink. The print head includes a type in which the ink tank is detachably mounted on the print head, and a type in which the ink tank is integrally formed with the print head. Regardless of the type, ink is consumed by discharging ink from the nozzles with the above-described recovery device. Therefore, when ink is ejected from the nozzles by the recovery device when the ink tank is low on ink, only a small amount of ink may remain in the nozzles or the nozzles may run out of ink. Similarly, even in a print head of a type in which an ink tank is detachably mounted, if ink is ejected from a nozzle when the ink tank is not mounted, only a small amount of ink remains in the nozzle or the nozzle runs out of ink. Sometimes.

[0007] A heater made of, for example, TaSiN is formed in the nozzle to discharge ink. Therefore,
If the nozzles run out of ink, the heater may be exposed and oxidized by contact with air. When only a small amount of ink remains in the nozzle, the remaining ink may dry and clog the nozzle. As described above, if the heater is oxidized or the nozzle is clogged, the print head is damaged and cannot be used.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an ink jet type image forming apparatus which prevents a print head from being damaged.

[0009]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising:
An ink tank in which ink is stored, a print head in which the ink tank is detachably mounted and a nozzle for discharging the ink stored in the ink tank is formed, and a carriage in which the print head is mounted, Recovery means for sucking ink from the nozzles and recovering the ink discharge state of the print head to the initial discharge state,
In an ink jet type image forming apparatus for forming an image on a recording medium by ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction, (1) detecting whether the ink tank is mounted on the print head. And (2) control means for controlling the print head so as not to eject ink from the nozzles when the ink tank detection means does not detect an ink tank. It is.

Here, (3) the carriage has a plurality of the print heads mounted thereon, and (4) the control means determines that the ink tank is one of the plurality of print heads mounted on the carriage. The print head may be controlled so that ink is not ejected from nozzles of the print head that is not mounted.

(5) The carriage has a plurality of the print heads mounted thereon, and (6) the control means includes at least one print head among the plurality of print heads mounted on the carriage. When the ink tank is not mounted, the print head may be controlled so that ink is not ejected from all the nozzles of the print head.

In order to achieve the above object, a second ink jet type image forming apparatus of the present invention has an ink tank in which ink is stored, and the ink tank is detachably mounted and stored in the ink tank. A print head provided with nozzles for discharging ink, a carriage on which the print head is mounted, and recovery means for sucking ink from the nozzles and restoring the ink discharge state of the print head to an initial discharge state. An ink jet type image forming apparatus which forms an image on a recording medium by ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction; (7) whether the ink tank is mounted on the print head; (8) The ink tank detection means detects the ink tank. Sometimes, it is characterized in that a control means for controlling so as not to start the recovery means.

Here, (9) the carriage has a plurality of the print heads mounted thereon, and (10) the control means determines that the ink tank is one of the plurality of print heads mounted on the carriage. The recovery means may be controlled so as not to suck ink from the nozzles of the print head that is not mounted.

(11) The carriage has a plurality of the print heads mounted thereon, and (12) the control means includes at least one print head among the plurality of print heads mounted on the carriage. When the ink tank is not mounted, the recovery means may be controlled so as not to suck ink from all the nozzles of the print head.

(13) The control means may control not to perform an image forming operation when the ink tank detecting means does not detect at least one ink tank.

In order to achieve the above object, a third ink jet type image forming apparatus of the present invention has an ink tank in which ink is stored, and the ink tank is detachably mounted and stored in the ink tank. A print head provided with nozzles for discharging ink, a carriage on which the print head is mounted, and recovery means for sucking ink from the nozzles and restoring the ink discharge state of the print head to an initial discharge state. An ink jet type image forming apparatus which forms an image on a recording medium by ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction. (14) The ink is stored in the ink tank mounted on the print head. (15) the ink detecting means for detecting whether or not the ink is stored; When no is characterized in that a control means for controlling the print head so as not to eject ink from the nozzle.

Here, (16) the carriage is provided with a plurality of the print heads, and (17) the control means is provided in the ink tank mounted on each of the plurality of print heads. The print head may be controlled so that the ink is not ejected from the nozzle of the print head to which the ink tank in which the ink is not detected by the ink detection unit is mounted.

(18) The carriage has a plurality of the print heads mounted thereon. (19) The control means includes at least one of the ink tanks mounted on each of the plurality of print heads. When the ink detecting means does not detect ink from the ink tank, the print head may be controlled so as not to eject ink from all the nozzles of the print head.

According to a fourth aspect of the present invention, there is provided an ink jet type image forming apparatus in which ink is stored, and the ink tank is detachably mounted and stored in the ink tank. A print head provided with nozzles for discharging ink, a carriage on which the print head is mounted, and recovery means for sucking ink from the nozzles and restoring the ink discharge state of the print head to an initial discharge state. An ink jet type image forming apparatus which forms an image on a recording medium by ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction. (20) Ink is stored in the ink tank mounted on the print head. An ink detecting means for detecting whether or not the ink is stored; and (21) the ink detecting means detects the ink. When no is characterized in that a control means for controlling so as not to start the recovery means.

Here, (22) the carriage is provided with a plurality of the print heads, and (23) the control means is configured to control the ink tank among the ink tanks mounted on the plurality of print heads. The recovery means may be controlled so as not to suck the ink from the nozzles of the print head equipped with the ink tank in which the ink is not detected by the ink detection means.

(24) The carriage has a plurality of the print heads mounted thereon. (25) The control means includes at least one of the ink tanks mounted on each of the plurality of print heads. When the ink detection means does not detect ink from the ink tank, the recovery means may be controlled so as not to suck ink from all the nozzles of the print head.

(26) The control means may control not to perform an image forming operation when the ink detecting means does not detect ink from at least one ink tank.

Further, (27) the print head includes:
Instead of the ink tank that is detachably mounted, an ink tank that is integrally formed with the print head may be used.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ink jet type image forming apparatus according to the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a plotter which is an example of the ink jet type image forming apparatus of the present invention will be described.

FIG. 1 is a perspective view showing a schematic configuration of the plotter.

The plotter 10 has a platen 14 on which the recording paper 12 conveyed in the direction of arrow A is placed. Above the platen 14, two scanning rails (guide rails) 16 are extended in parallel with the platen 14. The scanning rail 16 includes a motor (not shown)
The carriage 20 reciprocates in the directions of arrows B and C (in the direction perpendicular to the direction of arrow A) by means of the belt 18 and is mounted via a slide bearing (not shown).

The carriage 20 has four print heads 22K (black), 22C (cyan), 22M (magenta), and 22Y (yellow) having ink discharge ports (nozzle outlets, not shown) for discharging ink. ) Is installed. In front of the ink ejection port is an image forming area 23 where an image is formed. Ink is ejected from the ink ejection port to a portion of the recording paper 12 that is located in the image forming area 23, whereby an image is formed on this portion.

At a position on one side of the movable range of the carriage 20 distant from the image forming area 23, ink is forcibly sucked from the nozzles to clean the ink supply paths and nozzles formed on the print head 22. A recovery device 30 is provided for setting the ink discharge state of the print head 22 to the initial discharge state.

In forming an image on the recording paper 12 such as roll paper, the recording paper 12 is placed on a platen 14 and a part of the outer peripheral surface is opened through an opening (not shown) formed in the platen 14. The recording paper 12 is conveyed by rotating the conveyance roller 24 by a motor (not shown) while nipping the recording paper 12 by the conveyance roller 24 exposing the recording paper 12 and the pinch roller 26 for pressing both ends of the recording paper 12 from above. I do. The carriage 20 is reciprocated in the directions of arrows B and C above the recording paper 12, and an image signal carrying image information transmitted from the head control unit 44 (see FIG. 2) to each of the print heads 22K, 22C, 22M and 22Y. The ink is ejected from the nozzles based on the above, and an image is formed on a portion of the recording paper 12 located in the image forming area 23. During the image forming operation, when it becomes necessary to suck ink from the nozzles in order to clean the nozzles and the like, the carriage 20 is moved above the recovery device 30. When the image formation is completed, the cutter (not shown) mounted on the carriage 20 is protruded to a predetermined position to cut the recording paper 12 into a predetermined size.

The recovery device 30 includes four print heads 22.
Four rubber caps 32K, 32 that removably cover the respective outlets of the nozzles K, 22C, 22M, 22Y.
C, 32M, and 32Y. Each cap 32K,
One end of a tube (not shown) is connected to 32C, 32M, and 32Y, and the other end of the tube is connected to a suction pump (not shown). Four caps 32
K, 32C, 32M, and 32Y are fixed to the cap base 32.

The control system of the plotter 10 will be described with reference to FIG.

FIG. 2 is a block diagram showing a part of the control system of the plotter.

The plotter 10 has a built-in general control unit 40 (which is an example of the control means according to the present invention) for controlling various operations of the plotter 10. The general control unit 40
A recovery operation control unit 42 for controlling the operation of the recovery device 30 (see FIG. 1), and the print heads 22K, 22C, 2
A head control unit 44 for controlling the 2M, 22Y (see FIG. 1) ink discharge state. In addition, the general control unit 4
0 indicates a display unit 46 on which the operation status of the plotter 10 is displayed.
Also control. Further, the plotter 10 has an ink tank detection sensor 48 for detecting whether or not an ink tank (see FIG. 3) is mounted on each of the print heads 22K, 22C, 22M, and 22Y (see FIG. 1). A signal carrying the result detected by the ink tank detection sensor 48 is transmitted to the general control unit 40. In addition, plotter 1
0, each print head 22K, 22C, 22M, 22Y
An ink detection sensor 50 for detecting whether or not ink is stored in an ink tank (see FIG. 3) attached to the ink detection sensor (see FIG. 1) is provided.
Are also transmitted to the general control unit 40.

The structure of the carriage 20 and the print head 22 will be described with reference to FIG.

FIG. 3 is a schematic diagram showing a carriage on which a print head is mounted.

The print head 22 has a square hole 22a into which the boss 52a of the ink tank 52 is fitted, and a claw abutment 22b for fixing the ink tank 52. The ink tank 52 includes the ink tank 5.
An elastic claw 52b for fixing the print head 2 to the print head 22 is formed.

A positioning roller 20a is rotatably arranged near the scanning rail 16 on the carriage 20, and the positioning roller 20a is brought into contact with the scanning rail 16 to rotate the carriage 20. Is regulated and its position is determined. Also, the carriage 2
0, the positioning rollers 20a sandwiching the scanning rail 16
On the other side, the oscillating roller 20b urged in the direction toward the scanning rail 16 by the compression coil spring 54 is provided.
Are rotatably arranged. This oscillating roller 20b
It functions to abut the positioning roller 20 a against the scanning rail 16.

When the ink tank 52 is mounted on the print head 22, the boss 52 of the ink tank 52 is inserted into the square hole 22a.
a into the upper surface 52c of the ink tank 52 with the arrow A
Direction to engage the elastic claw 52b with the claw abutment 22b. Thus, the ink tank 52 is mounted on the print head 22. It should be noted that the print head 22 and the ink tank 5
The procedure for removing 2 is the reverse of the above procedure.

When the ink tank 52 mounted on the print head 22 is replaced, the upper surface 52 of the ink tank 52 is replaced.
c in the direction of arrow A (downward) so that the ink ejection surface 22c of the print head 22 approaches the platen 32, and the square hole 22a
The elastic claw 52b is released from the claw abutting portion 22b while the boss 52a is removed from the claw. Thereby, the ink tank 52
Is removed from the print head 22.

The ink tank detection sensor 48 and the ink detection sensor 50 shown in FIG. The detection table 60 is disposed in a non-image forming area outside the image forming area 23. Also, print head 2
A hole (not shown) for detecting the presence / absence of the ink tank 52 and for detecting the presence / absence of ink in the ink tank 52 is formed in a lower portion of the second container 2. When the carriage 20 passes beside the detection table 60, the ink tank detection sensor 48 optically detects whether or not the ink tank 52 is mounted on the print head 22. When the ink tank 52 is attached to the print head 22,
The ink detection sensor 50 optically detects whether or not ink is stored in the ink tank 52.

The recovery device 30 will be described with reference to FIG.

FIG. 4 is a schematic diagram showing a part of the recovery device.

The cap 32K is connected to a pump 36 for sucking ink from nozzles of the print head 22 (see FIG. 3) via an ink flow path 34 through which waste ink flows. The pump 36 is connected to a waste ink tank (not shown) via an ink flow path 38.

Each print head 22K, 22C, 22M, 2
2Y (see FIG. 1) are caps 32K, 32C, respectively.
When it reaches above 32M and 32Y (see FIG. 1) and stops, the cap 32 is moved by a solenoid (not shown) or the like.
K, 32C, 32M, and 32Y rise and each print head 2
The ink discharge ports of 2K, 22C, 22M, and 22Y are closed.
In this state, the pump 36 is driven and the caps 32K, 3
A negative pressure is generated inside 2C, 32M, and 32Y. Thereby, each print head 22K, 22C, 22M, 22Y
Then, the ink is sucked from the nozzle and the recovery operation is executed. Further, each print head 22K, 22C, 22M, 22
Caps 32K, 32C, 32M,
In a state where there is no blockage at 32Y, a predetermined amount of ink is ejected from each ink ejection port to perform a preliminary ejection operation.

The procedure of the recovery operation will be described with reference to FIGS.

First, a first example of the procedure of the recovery operation will be described with reference to FIG.

FIG. 5 is a flowchart showing a first example of the procedure of the recovery operation.

This flow is based on the plotter 10 (see FIG. 1).
It starts when the power supply of is turned on. Based on a signal from the ink tank detection sensor 48 (see FIG. 2), the general control unit 4
0 (see FIG. 2), each print head 22K, 22C, 2
It is determined whether or not the ink tank 52 is mounted on 2M, 22Y (S501). When the ink tank 52 is not installed, the general control unit 40 controls the head control unit 44 so that the image forming operation is prohibited (printing is prohibited).
(See FIG. 2) is controlled (S502). Therefore, since the image forming operation is not performed, no ink is ejected from the print head to which the ink tank 52 is not attached, and it is possible to prevent the print head from completely losing the ink.
As a result, the heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After the printing is prohibited, the display unit 46 indicates that the ink tank 52 is not mounted.
(See FIG. 2) to warn the user (S503),
A print head replacement mode for replacing the print head with the ink tank 52 is executed (S504).

When it is determined in step S501 that the ink tank 52 is mounted on each of the print heads 22K, 22C, 22M, and 22Y, it is determined whether or not ink is stored in the ink tank 52 (the presence or absence of the remaining ink). Is determined (S
505). When it is determined that no ink is stored in the ink tank 52 (there is no remaining ink), the general control unit 40 controls the head control unit 44 so that the image forming operation is prohibited (printing is prohibited). (S506). Therefore, since the image forming operation is not performed, the ink tank 5
Ink is not ejected from the print head to which No. 2 is mounted, and it is possible to prevent the print head from completely losing ink. As a result, the heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After the printing is prohibited, the display unit 46 (see FIG. 2) displays that the ink tank 52 is not mounted to warn the user (S
507), the print head exchange mode is executed (S50).
8). If it is determined in S505 that ink is stored in the ink tank 52 (there is ink remaining), the general control unit 40 controls the head control unit 44 to perform a printing operation (S509).

Further, control may be performed so that ink is not ejected from the nozzles of the print heads of the print heads 22K, 22C, 22M, and 22Y mounted on the carriage 20 to which the ink tank 52 is not mounted. Further, each print head 22K, 22C,
When the ink tank 52 is not attached to at least one of the print heads 22M and 22Y, the print heads may be controlled so that ink is not ejected from the nozzles of all the print heads 22K, 22C, 22M and 22Y. .

Each of the print heads 22K, 22C, 22
Of the ink tanks 52 mounted on each of the M and 22Y, control may be performed so that the ink is not sucked from the nozzles of the print head in which the ink detection sensor 50 detects no ink. further,
When the ink detection sensor 50 does not detect ink from at least one of the ink tanks 52 mounted on each of the print heads 22K, 22C, 22M, and 22Y, all of the print heads 22K, 22C, and 22Y.
Control may be performed so that ink is not sucked from the M and 22Y nozzles.

A second example of the procedure of the recovery operation will be described with reference to FIG.

FIG. 6 is a flowchart showing a second example of the procedure of the recovery operation.

This flow is based on the plotter 10 (see FIG. 1).
It starts when the power supply of is turned on. Based on a signal from the ink tank detection sensor 48 (see FIG. 2), the general control unit 4
0 (see FIG. 2), each print head 22K, 22C, 2
It is determined whether the ink tank 52 is mounted on the 2M, 22Y (S601). When the ink tank 52 is not mounted, the general control unit 40 controls the recovery operation control unit 42 (see FIG. 2) so that the recovery operation is prohibited (S602). Therefore, since the recovery operation is not performed, no ink is ejected from the print head to which the ink tank 52 is not attached, and it is possible to prevent the print head from completely losing the ink. As a result, the heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After the printing is prohibited, the display unit 46 (see FIG. 2) displays that the ink tank 52 is not mounted to warn the user (S603), and prints to replace the print head with the ink tank 52 mounted. The head exchange mode is executed (S604).

If it is determined in step S601 that the ink tank 52 is mounted on each of the print heads 22K, 22C, 22M, and 22Y, it is determined whether or not ink is stored in the ink tank 52 (the presence or absence of the remaining ink). Is determined (S
605). When it is determined that no ink is stored in the ink tank 52 (there is no remaining ink), the general control unit 40 controls the recovery operation control unit 4 so that the recovery operation is prohibited.
2 is controlled (S606). Therefore, since the recovery operation is not performed, no ink is ejected from the print head to which the ink tank 52 is not attached, and it is possible to prevent the print head from completely losing the ink. As a result, the heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After printing is prohibited, the ink tank 52
Is displayed on the display unit 46 (see FIG. 2) to warn the user (S607), and the print head replacement mode is executed (S608). When it is determined in S605 that ink is stored in the ink tank 52 (there is ink remaining), the general control unit 40 controls the head control unit 44 to perform a recovery operation (S60).
9).

In addition, control may be performed so that the recovery operation of the print heads, to which the ink tank 52 is not mounted, among the print heads 22K, 22C, 22M, and 22Y mounted on the carriage 20 is not performed. Further, the carriage 20
Print heads 22K, 22C, 22M, 2
When the ink tank 52 is not mounted on at least one of the print heads 2Y, all the print heads 22
Control may be performed so that the recovery operation of K, 22C, 22M, and 22Y is not performed.

Each of the print heads 22K, 22C, 22
Of the ink tanks 52 mounted on each of the M and 22Y, control may be performed so as not to perform the recovery operation of the print head in which the ink tank in which ink is not detected by the ink detection sensor 50 is mounted. Further, when the ink detection sensor 50 does not detect ink from at least one of the ink tanks 52 mounted on each of the print heads 22K, 22C, 22M, and 22Y, all the print heads 22K, 22C, 22M, 22Y
May be controlled so as not to perform the recovery operation.

A third example of the procedure of the recovery operation will be described with reference to FIG.

FIG. 7 is a flowchart showing a third example of the procedure of the recovery operation.

This flow is based on the plotter 10 (see FIG. 1).
It starts when the power supply of is turned on. Based on a signal from the ink tank detection sensor 48 (see FIG. 2), the general control unit 4
0 (see FIG. 2), each print head 22K, 22C, 2
It is determined whether the ink tank 52 is mounted on the 2M, 22Y (S701). When the ink tank 52 is not mounted, the general control unit 40 controls the head control unit 44 (see FIG. 2) so as to prohibit the image forming operation and the general control unit so that the recovery operation is prohibited. 4
0 controls the recovery operation control unit 42 (see FIG. 2) (S7).
02). Therefore, since the image forming operation and the recovery operation are not executed, the ink is not ejected from the print head to which the ink tank 52 is not attached, and it is possible to prevent the print head from completely losing the ink. As a result, the heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After the printing is prohibited, the display unit 46 (see FIG. 2) displays that the ink tank 52 is not mounted to warn the user (S703), and prints to replace the print head with the ink tank 52 mounted. The head exchange mode is executed (S704).

When it is determined in S701 that the ink tank 52 is mounted on each of the print heads 22K, 22C, 22M, and 22Y, it is determined whether or not ink is stored in the ink tank 52 (the presence or absence of the remaining ink). Is determined (S
705). When it is determined that no ink is stored in the ink tank 52 (there is no remaining ink), the general control unit 40 controls the head control unit 44 (see FIG. 2) so that the image forming operation is prohibited. At the same time, the comprehensive control unit 40 controls the recovery operation control unit 42 (FIG. 2) so that the recovery operation is prohibited.
(See S706). Therefore, since the recovery operation is not performed, no ink is ejected from the print head to which the ink tank 52 is not attached, and it is possible to prevent the print head from completely losing the ink. As a result,
The heater incorporated in the print head can be prevented from being oxidized by contact with air, and the print head can be prevented from being damaged. After printing is prohibited, the display unit 46 indicates that the ink tank 52 is not mounted (see FIG. 2).
Is displayed to warn the user (S707), and the print head replacement mode is executed (S708). When it is determined in step S705 that ink is stored in the ink tank 52 (there is ink remaining), the general control unit 40 and the head control unit 44 perform a recovery operation so as to perform an image forming operation and a recovery operation. The controller 42 is controlled (S709).

[0063]

As described above, according to the first ink jet type image forming apparatus of the present invention, when the ink tank detecting means does not detect the ink tank, the control means does not discharge ink, so that printing is performed. It is possible to prevent the ink from completely disappearing from the head. As a result, it is possible to prevent the heater built in the print head from being oxidized by contact with air. Therefore, it is possible to prevent the print head from being damaged.

Here, the carriage has a plurality of the print heads mounted thereon, and the control means controls the print head which is not mounted with the ink tank among the plurality of print heads mounted on the carriage. In the case where the print head is controlled so as not to eject ink from the nozzle, the print head to which the ink tank is not mounted can be prevented from being damaged.

Further, the carriage has a plurality of the print heads mounted thereon, and the control means controls whether the ink tank is mounted on at least one of the plurality of print heads mounted on the carriage. Otherwise, when the print head is controlled so that ink is not ejected from all the nozzles of the print head, breakage of a plurality of print heads can be prevented more reliably.

According to the second image forming apparatus of the present invention, when the ink tank detecting means does not detect the ink tank, the control means does not activate the recovery means, so that the ink is completely discharged from the print head. Can be prevented from being lost. As a result, it is possible to prevent the heater built in the print head from being oxidized by contact with air.
Therefore, it is possible to prevent the print head from being damaged.

Here, the carriage has a plurality of the print heads mounted thereon, and the control means controls the print head which is not mounted with the ink tank among the plurality of print heads mounted on the carriage. If the recovery means is controlled so as not to suck the ink from the nozzles of the ink tank, it is possible to prevent the print head without the ink tank from being damaged, and to prevent the ink of the print head with the ink tank from being damaged. The ejection state can be restored to the initial ejection state.

Further, the carriage has a plurality of the print heads mounted thereon, and the control means controls whether the ink tank is mounted on at least one of the plurality of print heads mounted on the carriage. Otherwise, if the recovery means is controlled so as not to suck ink from all the nozzles of the print head, breakage of a plurality of print heads can be more reliably prevented.

When the ink tank detecting means does not detect at least one ink tank, the control means controls so as not to perform an image forming operation. Although no ink is consumed, the image forming operation is not performed, so that it is possible to prevent an image defect due to the absence of ink from occurring.

According to the third ink jet type image forming apparatus of the present invention, when the ink detecting means does not detect the ink, the ink is not ejected from the nozzle, so that it is possible to prevent the ink from completely disappearing from the print head. As a result, it is possible to prevent the heater built in the print head from being oxidized by contact with air. Therefore, it is possible to prevent the print head from being damaged.

Here, the carriage has a plurality of the print heads mounted thereon, and the control means controls the ink detecting means of the ink tanks mounted on each of the plurality of print heads so that the ink is detected by the ink detection means. If the print head is controlled so that ink is not ejected from the nozzles of the print head with undetected ink tanks, the print head with ink tanks without ink is prevented from being damaged it can.

Further, the carriage has a plurality of the print heads mounted thereon, and the control means controls the ink detection means from at least one of the ink tanks mounted on each of the plurality of print heads. If the print head is controlled so that no ink is ejected from all the print head nozzles when no ink is detected, breakage of a plurality of print heads can be prevented more reliably.

According to the fourth ink jet type image forming apparatus of the present invention, when the ink detecting means does not detect the ink, the control means does not activate the recovery means, so that the ink is completely removed from the print head. Can be prevented. As a result, it is possible to prevent the heater built in the print head from being oxidized by contact with air. Therefore, it is possible to prevent the print head from being damaged.

Here, the carriage has a plurality of the print heads mounted thereon, and the control means controls the ink detecting means of the ink tanks mounted on each of the plurality of print heads. If the above recovery means is to be controlled so that ink is not sucked from the nozzles of the print head equipped with the undetected ink tank, the print head equipped with the ink tank without ink is prevented from being damaged In addition, it is possible to recover the ink discharge state of the print head in which the ink tank containing the ink is mounted to the initial discharge state.

Further, the carriage has a plurality of the print heads mounted thereon, and the control means controls the ink detection means from at least one of the ink tanks mounted on each of the plurality of print heads. If the control unit controls the recovery means so as not to suck the ink from all the nozzles of the print head when no ink is detected, damage to the plurality of print heads can be prevented more reliably.

Further, when the ink detecting means does not detect ink from at least one ink tank, the control means controls so as not to perform an image forming operation. Although the ink is not discharged from the head, the image forming operation is not performed, so that it is possible to prevent the occurrence of an image defect due to the absence of the ink.

Further, when the print head has an ink tank integrally formed with the print head instead of the ink tank which is detachably mounted, the print head can Damage can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a plotter according to the present invention.

FIG. 2 is a block diagram showing a part of a control system of the plotter.

FIG. 3 is a schematic diagram illustrating a carriage on which a print head is mounted.

FIG. 4 is a schematic view showing a part of the recovery device.

FIG. 5 is a flowchart showing a first example of a procedure of a recovery operation.

FIG. 6 is a flowchart showing a second example of the procedure of the recovery operation.

FIG. 7 is a flowchart showing a third example of the procedure of the recovery operation.

[Explanation of symbols]

 Reference Signs List 10 plotter 20 carriage 22K, 22C, 22M, 22Y print head 40 general control unit 42 recovery operation control unit 44 head control unit 48 ink tank detection sensor 50 ink detection sensor

Claims (15)

[Claims] An ink tank storing ink, a print head in which the ink tank is detachably mounted and a nozzle for discharging the ink stored in the ink tank is formed, and the print head is mounted. And a recovery means for sucking ink from the nozzles to recover the ink discharge state of the print head to an initial discharge state, and ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction. An ink-jet image forming apparatus that forms an image on a recording medium by detecting whether or not the ink tank is mounted on the print head; and when the ink tank detecting means does not detect the ink tank. Control means for controlling the print head so as not to discharge ink from the nozzles Inkjet type image-forming apparatus characterized by. 2. The printing apparatus according to claim 1, wherein the carriage is provided with a plurality of the print heads, and the control unit is configured to control a print head to which the ink tank is not mounted among the plurality of print heads mounted on the carriage. 2. The ink jet type image forming apparatus according to claim 1, wherein the print head is controlled so that ink is not ejected from a nozzle. 3. The carriage has a plurality of the print heads mounted thereon, and the control means is configured to mount the ink tank on at least one of the plurality of print heads mounted on the carriage. 2. The inkjet image forming apparatus according to claim 1, wherein the control unit controls the print head so as not to eject ink from all the nozzles of the print head when the print head is not in operation. 4. An ink tank in which ink is stored, a print head in which the ink tank is removably mounted and a nozzle for discharging the ink stored in the ink tank is formed, and the print head is mounted. And a recovery means for sucking ink from the nozzles to recover the ink discharge state of the print head to an initial discharge state, and ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction. An ink-jet image forming apparatus that forms an image on a recording medium by detecting whether or not the ink tank is mounted on the print head; and when the ink tank detecting means does not detect the ink tank. Control means for controlling the recovery means so as not to be activated. Jet type image forming apparatus. 5. The printing apparatus according to claim 1, wherein the carriage is provided with a plurality of the print heads, and the control unit is configured to control a print head to which the ink tank is not mounted among the plurality of print heads mounted on the carriage. 5. The ink jet image forming apparatus according to claim 4, wherein the recovery unit is controlled so as not to suck ink from the nozzle. 6. The carriage, on which the plurality of print heads are mounted, wherein the control means is configured to mount the ink tank on at least one of the plurality of print heads mounted on the carriage. 5. The ink-jet image forming apparatus according to claim 4, wherein the control unit controls the recovery unit so as not to suck ink from all the nozzles of the print head when the print head is not in use. 7. The image forming apparatus according to claim 4, wherein the control unit controls not to perform an image forming operation when the ink tank detecting unit does not detect at least one ink tank.
7. The ink jet image forming apparatus according to item 5 or 6. 8. A print head in which ink is stored, an ink tank is removably mounted, and a print head is formed with nozzles for discharging the ink stored in the ink tank. And a recovery means for sucking ink from the nozzles to recover the ink discharge state of the print head to an initial discharge state, and ejecting ink from the nozzles while reciprocating the carriage in a predetermined direction. An ink-jet image forming apparatus that forms an image on a recording medium by detecting whether or not ink is stored in the ink tank attached to the print head; and Control means for controlling the print head so as not to eject ink from the nozzles when no detection is performed. Inkjet type image-forming apparatus characterized by. 9. The carriage, on which a plurality of the print heads are mounted, wherein the control means detects ink by the ink detection means among the ink tanks mounted on each of the plurality of print heads. 9. The ink jet type image forming apparatus according to claim 8, wherein the print head is controlled so that ink is not ejected from a nozzle of the print head to which an ink tank that is not mounted is mounted. 10. The carriage, on which a plurality of the print heads are mounted, wherein the control means includes an ink detection means for detecting an ink from at least one of the ink tanks mounted on each of the plurality of print heads. 9. When the printer does not detect ink, the print head is controlled so that ink is not ejected from all the nozzles of the print head.
3. An ink jet type image forming apparatus according to claim 1. 11. An ink tank in which ink is stored,
A print head in which the ink tank is detachably mounted and a nozzle for ejecting ink stored in the ink tank is formed, a carriage on which the print head is mounted, and ink sucked from the nozzle to Recovery means for recovering the ink discharge state of the print head to the initial discharge state, wherein the ink jet image forming apparatus forms an image on a recording medium by discharging ink from the nozzles while reciprocating the carriage in a predetermined direction. An ink detecting means for detecting whether or not ink is stored in the ink tank mounted on the print head; and controlling not to activate the recovery means when the ink detecting means does not detect ink. An ink jet type image forming apparatus, comprising: a control unit. 12. The carriage, on which a plurality of the print heads are mounted, wherein the control unit detects ink by the ink detection unit in the ink tank mounted on each of the plurality of print heads. 12. The ink jet type image forming apparatus according to claim 11, wherein the control unit controls the recovery unit so as not to suck ink from a nozzle of a print head having an ink tank that is not mounted. 13. The carriage, on which the plurality of print heads are mounted, wherein the control means includes: an ink detection means for detecting an ink from at least one of the ink tanks mounted on each of the plurality of print heads. 12. The printer according to claim 11, wherein when no ink is detected, the recovery unit is controlled so as not to suck ink from all nozzles of the print head.
3. An ink jet type image forming apparatus according to claim 1. 14. The image forming apparatus according to claim 1, wherein the control unit controls so as not to perform an image forming operation when the ink detecting unit does not detect ink from at least one ink tank.
14. The inkjet type image forming apparatus according to 1, 12, or 13. 15. The print head according to claim 1, wherein the print head has an ink tank integrally formed with the print head instead of an ink tank detachably mounted. The inkjet image forming apparatus according to any one of the above.