JP4192500B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus such as an ink jet printer, and in particular, a sub ink tank and a recording head are integrated and mounted on a carriage, and the sub ink tank and the main ink tank are connected by a tube or the like. The present invention relates to an ink jet recording apparatus in which a main ink tank connected to a sub ink tank can be replaced accordingly.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a serial type inkjet recording apparatus that performs recording by discharging ink from an ink discharge port provided in a recording head, one that performs recording by reciprocating a carriage having an ink tank mounted on the recording head is known. Yes.
[0003]
In such a conventional ink jet recording apparatus, an ink tank containing a plurality of types of ink is mounted on a carriage. In order to prevent ink from dripping from the recording head, the ink tank needs to be maintained at a negative pressure in a steady state. For this reason, a porous negative pressure generating member such as a sponge is required in the ink tank, and sufficient ink is required. In order to maintain the amount, the volume of the ink tank becomes considerably large with respect to the internal volume of the ink, resulting in an increase in the size of the carriage.
[0004]
In order to avoid such a problem, an ink supply system that supplies ink to the recording head from a main ink tank fixed to the apparatus main body side through a sub ink tank connected by a flexible tube or the like is used. .
[0005]
When such a method is used, an ink supply system can be realized with a very simple configuration, and the sub ink tank on the carriage does not require a negative pressure generating member such as a sponge, and has a small internal volume of about 1 cc. Since only the sub ink tank needs to be mounted, the carriage can be reduced in size. Further, by providing the main ink tank at a position about 20 to 100 mm lower than the discharge port surface of the recording head, the above-mentioned negative pressure generating member is not required in the main ink tank due to the water head pressure difference, and the ink with respect to the volume of the main ink tank Filling efficiency is improved.
[0006]
[Problems to be solved by the invention]
The flexible tube connecting the main ink tank and the sub ink tank is made of rubber or resin, and therefore has a slight gas permeability. Also, since the negative pressure in the tube is the same as that of the recording head, air gradually enters the tube through the tube wall from the atmosphere, and bubbles are generated when left for a long time. Furthermore, air bubbles enter the tube when the main ink tank is replaced. When the bubbles flow into the recording head, normal ink droplets cannot be ejected, and printing failure occurs.
[0007]
In order to avoid such a printing failure state, a suction recovery operation is performed according to the state of the apparatus or a user instruction.
[0008]
The suction recovery operation is realized by pressing the cap member against the ejection port surface of the recording head, operating the ink suction means, sucking ink from the ejection port, and filling the recording head with ink from the main ink tank. .
[0009]
However, in the conventional apparatus, in order to perform the recovery operation with certainty, the ink suction means is set to suck ink corresponding to the volume of all ink flow paths from the recording head to the main ink tank. For this reason, all the ink remaining in the ink flow path is discarded, the amount of ink that can actually be used for recording is reduced, and the ink use efficiency is greatly reduced.
[0010]
An object of the present invention is to solve the above problems and minimize the amount of ink to be discarded by sucking the ink amount corresponding to the remaining state of the ink in the ink flow path from the main ink tank to the recording head. An object of the present invention is to provide an ink jet recording apparatus capable of performing the above.
[0011]
[Means for Solving the Problems and Effects of the Invention]
An ink jet recording apparatus according to the present invention is formed integrally with a recording head for recording by discharging ink from an ejection port formed on an ejection port forming surface, and the recording head for supplying ink to the recording head. A sub ink tank, a carriage that is mounted with the recording head and the sub ink tank, and that can move a predetermined recording area and its adjacent area in the main scanning direction, a main ink tank that can supply ink to the sub ink tank, Connecting means that connects the sub ink tank and the main ink tank and is capable of coming into contact with and leaving the main ink tank; and contacting and leaving the discharge port forming surface of the recording head disposed in the adjacent area. Cap member, a suction unit that sucks ink from the ejection port of the recording head via the cap member, and the suction unit And a control unit for controlling the ink jet recording apparatus. The ink jet recording apparatus further includes a first ink remaining amount detecting unit that detects the presence or absence of the remaining amount of ink in the sub ink tank. , a suction recovery operation at the time of initial filling, that is intended to perform by selecting one from the detection result to the result with two suction recovery operation of different ink suction amount of the first ink remaining amount detecting means It is a feature.
[0012]
The main ink tank is fixedly provided on the apparatus main body side.
[0013]
The connecting means is normally in contact with the main ink tank and is detached from the main ink tank when the main ink tank is replaced.
[0014]
The suction recovery operation is performed when a recovery operation instruction is issued. The recovery operation instruction is automatically output according to the state of the apparatus. It is also output by the user's recovery operation.
[0015]
For example, if the detection result of the remaining amount detecting means is remaining, a small recovery sequence is performed. This is a recovery operation in which a very small amount of ink is sucked for a short time in order to refresh the ink in the recording head. When the detection result of the remaining amount detecting means is no remaining amount, the middle recovery sequence is performed. This is a recovery operation for sucking a relatively small amount of ink, although it is more than the small recovery sequence in order to suck a certain amount of ink into the sub ink tank.
[0016]
Further, a large recovery sequence is performed at the time of initial filling, that is, when the apparatus is used for the first time or when the apparatus is left for a long time. This is a recovery operation that sucks ink for a long time and fills the connecting means, the sub ink tank, and the recording head with ink from the main ink tank so that printing can be started.
[0017]
According to the ink jet recording apparatus of the present invention, and whether the initial charge, the detection result of the first ink remaining amount detecting means, i.e., depending on the presence or absence of the ink remaining amount in the sub-ink tank, proper ink A suction operation can be performed. Therefore, wasteful ink is not discarded by the suction recovery operation, the ink use efficiency is improved, the main ink tank is downsized, the waste ink pad is downsized, the cost is reduced, and the entire inkjet recording apparatus is downsized. It becomes possible.
[0018]
In the ink jet recording apparatus of the present invention, for example, a second ink remaining amount detecting unit that detects the presence or absence of the remaining amount of ink in the main ink tank is provided, and the control unit includes a second ink remaining amount detecting unit. According to the detection result, replacement of the main ink tank is instructed.
[0019]
According to this, when the main ink tank needs to be replaced, the replacement can be surely instructed.
[0020]
In the ink jet recording apparatus of the present invention, for example, a filter member that prevents air from entering the connecting means when the main ink tank is detached is provided at a portion of the connecting means that contacts the main ink tank.
[0021]
According to this, since an ink film is formed on the filter member, air does not enter the connecting means when the main ink tank is detached from the connecting means for replacing the main ink tank. Therefore, it is not always necessary to perform the suction recovery operation after replacing the main ink tank, and the amount of ink discarded can be further reduced.
[0022]
For example, a plurality of sub ink tanks are integrated with the recording head, and a plurality of ejection openings corresponding to the respective sub ink tanks are formed.
[0023]
Further, for example, a recording head discharges ink by applying an electric field to a polarized piezoelectric member to cause shear deformation of the piezoelectric member and applying pressure waves to ink filled in the ink chamber. is there.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to an inkjet printer will be described with reference to the drawings.
[0025]
FIG. 1 is a partially cutaway rear view of the printing unit of the printer as viewed from the rear side (upstream side) in the recording paper conveyance direction, and FIG. 2 is a partially cutaway plan view thereof. In the description of the embodiment, front, rear, left, and right refer to the recording sheet conveyance direction in the printing unit. In the printing section, the recording paper is conveyed from the front side of the paper surface to the back side of the paper surface in FIG. 1, so that the upper side in FIG. 2 (back side of the paper surface in FIG. 1) is the front and the lower side in FIG. Yes, the left and right in FIGS. 1 and 2 are the left and right.
[0026]
As shown in FIGS. 1 and 2, a guide rod (2) that is fixed to the housing (1) of the apparatus main body and extends in the left-right direction, which is the main scanning direction, is provided in the printing unit of the printer. (3) is installed. The carriage (3) is moved in the left-right direction along the guide rod (2) by an appropriate driving means (not shown). Of the moving area of the carriage (3), the area excluding the right end is a recording area where the carriage (3) reciprocates during printing, and the right end area adjacent to the recording area is a maintenance area.
[0027]
A recording head (4) and a plurality (four in this example) of sub ink tanks (5a) (5b) (5c) (5d) are mounted on the carriage (3). The sub ink tanks are collectively referred to by reference numeral (5). The sub tank (5) is integrally provided on the recording head (4).
[0028]
Although not shown, a plurality of discharge ports corresponding to the respective sub tanks (5) are formed on the discharge port forming surface on the lower surface of the recording head (4). The recording head (4) discharges ink by applying an electric field to the polarized piezoelectric member to cause shear deformation of the piezoelectric member and applying a pressure wave to the ink filled in the ink chamber. It has become.
[0029]
The same number of main ink tanks (6a) (6b) (6c) (6d) as the sub tanks (5) are detachably provided in the lower part of the housing (1). The main ink tank is generically designated by reference numeral (6). The corresponding ones of the main tank (6) and the sub tank (5) are connected by a connecting device (7) that constitutes connecting means. Although not shown, the main tank (6) is attached to a holder provided in the housing (1), and thereby contacts the connection device (7) and is connected to the corresponding sub tank (5). .
[0030]
3 shows details of the sub-tank (5), FIG. 4 shows details of the main tank (6), and FIG. 5 shows details of the connecting device (7).
[0031]
The connection device (7) includes a connection block (8) that is fixed to the housing (1) and can be brought into and out of contact with the main tank (6), and the connection block (8) and the sub tank (5). It consists of a tube (9) to be connected. Although the detailed illustration is omitted, the tube (9) is bundled and protected by a cover member so that the movement of the carriage (3) is not hindered.
[0032]
As shown in FIG. 5, the connection block (8) has a rectangular parallelepiped shape, and an ink flow path (10) reaching from the one side surface to the upper surface is formed. The end of the tube (9) is inserted and fixed on the side surface side of the channel (10), and is sealed by the seal member (11). A short cylindrical portion (12) is integrally formed in the upper surface opening of the channel (10). A seal member (13) is provided on the upper surface of the block (8) around the cylindrical portion (12). A filter member (14) is provided at the upper end opening of the metering passage (10) of the cylindrical portion (12).
[0033]
As shown in FIG. 4, the main tank (6) has a substantially rectangular parallelepiped shape, and a cylindrical portion (15) is integrally formed on the lower surface thereof. The cylindrical portion (15) is formed with an ink flow path (16) that penetrates the cylindrical portion (15) vertically and communicates with the inside of the main tank (6). The lower end opening of the channel (16) has an inner diameter larger than that of the other part, and a porous member (17) such as a sponge is fitted in this part. A filter member (18) is provided between the upper end of the flow path (16) and the inside of the main tank (6).
[0034]
The main tank (6) is filled with a porous member (19) such as sponge for generating negative pressure, and an air communication hole (20) is formed on the upper wall of the main tank (6). Has been.
[0035]
As shown in FIG. 3, a hollow projecting portion (21) communicating with the inside of the sub tank (5) is formed at the lower portion of one side surface of the sub tank (5), and a tube is formed at the tip of the projecting portion (21). (9) is connected. Usually, the lower half of the sub tank (5) is filled with ink, and the upper half of the sub tank (5) is an air layer. An ink supply hole (22) to the recording head (4) is formed in the bottom wall of the sub tank (5). Ink flow due to the operation of the carriage (3) is directly applied to the recording head (4) between the portion of the sub tank (5) where the ink supply hole (22) is formed and the portion on the protruding portion (21) side. A partition wall (23) for preventing transmission is provided. The air layer and the partition wall (23) minimize the influence of ink flow during acceleration / deceleration of the carriage (3).
[0036]
The internal capacity of the main tank (6) is sufficiently larger than the internal capacity of the sub tank (5). At least the projecting portion (21) of the sub tank (5) is made of a translucent material such as transparent plastics. For example, the entire sub tank (5) is made of a translucent material. The protruding portion (21) is provided with a first ink remaining amount sensor (24) constituting a first ink remaining amount detecting means. The sensor (24) is composed of a light emitting element (25) and a light receiving element (26) arranged opposite to each other with the protruding part (21) in between, and the light receiving element (26) and the inside of the protruding part (21), that is, the sub tank An electrical signal corresponding to the ink remaining amount in (5) is output. Thereby, the presence or absence of the remaining amount of ink in the sub tank (5) is detected. The cylindrical portion (15) of the main tank (6) is provided with a second ink remaining amount sensor (27) constituting second ink remaining amount detecting means. The sensor (27) is composed of a pair of electrodes (28) and (29) on both outer surfaces of the cylindrical portion (15) so as to sandwich the flow path (16). Although not shown, when the main tank (6) is mounted on the holder, the electrodes (28) and (29) of the sensor (27) come into contact with the electrodes provided on the holder side, and the electrodes (28) (29 ) Is applied with an AC voltage. Then, by detecting the capacitance between the electrodes (28) and (29), the presence or absence of the remaining amount of ink in the flow path (16) is detected.
[0037]
A cap member (30) for performing a suction recovery operation is provided in the maintenance area so as to be movable up and down. A waste ink reservoir (31) is provided at the bottom of the housing (1), and a suction pump (32) that constitutes suction means is provided between the waste ink reservoir (31) and the cap member (30). .
[0038]
FIG. 6 shows an example of the main part of the electrical configuration of the printer.
[0039]
The printer includes a control unit (33) for controlling the entire printer. A power-on switch (34), a built-in timer (35), and the like are connected to the control unit (33), and the outputs of the two remaining ink sensors (24) and (27), maintenance instruction signals, and the like are transmitted to the control unit (33). To enter. As will be described later, the control unit (33), during maintenance, drives the suction pump (32) based on the maintenance instruction signal, the outputs of the sensors (24) and (27), the built-in timer (35), etc. 36), thereby controlling the suction recovery operation.
[0040]
When starting to use the printer, the main tank (6) is mounted on the holder, so that the cylindrical portion (15) of the main tank (6) fits outside the cylindrical portion (12) of the block (8). Then, the seal member (13) is pressed against and the space between them is sealed. Then, the carriage (3) is stopped at a predetermined maintenance position in the maintenance area, the cap member (30) is raised, and comes into contact with the discharge port forming surface of the recording head (4), thereby blocking the discharge port. Then, the pump (32) is driven to fill the sub tank (5) and the recording head (4) with ink from the main tank (6) through the connecting device (7).
[0041]
During normal use, recording is performed by ejecting ink from the ejection ports of the recording head (4) as described above while the carriage (3) reciprocates in the recording area. Even if ink in the sub-tank (6) is consumed by ink discharge from the recording head (4) for printing, the consumed ink is automatically generated by the capillary force of the discharge port of the recording head (4). Thus, the sub-tank (5) and the connecting device (7) are not emptied.
[0042]
When performing maintenance, the cap member (30) comes into contact with the discharge port forming surface of the recording head (4) of the carriage (3) stopped at the maintenance position, and the pump (32) is driven, so that the ink is discharged from the discharge port. Is sucked, and the sub tank (5) and the recording head (4) are filled with ink. The ink sucked by the pump (32) is stored in the waste ink reservoir (31).
[0043]
When the main tank (6) becomes empty, the main tank (6) is removed from the holder, and a new main tank (6) is mounted. When the main tank (6) is removed from the holder, the main tank (6) is detached from the block (8), but an ink film is formed on the filter member (14) portion of the block (8) by capillary force, and the connecting device (7) Air intrusion is prevented. Then, when the new main tank (6) is mounted on the holder, the porous member (17) of the main tank (6) filled with ink and the filter member (14) of the block (8) are in close contact with each other by capillary force. The ink can be supplied again. For this reason, when the main tank (6) is replaced, it is not always necessary to perform maintenance. The porous member 17 of the main tank 6 holds an amount of ink that can print one page of recording paper. For this reason, even if there is no ink in the flow path (16), printing can be performed with the ink held in the porous member (17).
[0044]
The control unit (33) performs maintenance when receiving an instruction to execute the suction recovery operation, for example, when detecting that the printer has been left for a long time or when receiving an instruction from the user. At this time, the control unit (33) performs a plurality of types of suction recovery with different operation times or operation counts set in advance based on the detection results of the remaining ink levels by the two remaining ink sensors (24) and (27). An optimum suction recovery operation is selected from the operations, and suction recovery operations with different ink suction amounts are performed.
[0045]
Next, an example of the operation at the time of maintenance will be described with reference to the flowchart of FIG.
[0046]
When there is a maintenance instruction, first, it is checked whether or not the initial filling is performed (S1). If so, a large recovery sequence is performed (S2), and the process is terminated. Whether or not the initial filling is performed is determined with reference to the initial filling operation flag in the memory. If this flag is set, it is determined that the initial filling is performed, and a large recovery sequence is performed. Once the large recovery sequence is performed, the initial filling flag is cleared. If the printer is left unattended for a long time, the initial filling flag is set again by the built-in timer (35). In the large recovery sequence, ink is sucked for a long time by the pump (32), and ink is filled from the main tank (6) to the block (8), the tube (9), the sub tank (5) and the recording head (4). This is a recovery operation that allows printing to be started.
[0047]
In S1, if there is no initial filling, the output of the second sensor (27) is checked for the remaining amount of ink in the main tank (6) (S3). The main tank (6) is instructed to be exchanged (S4), waits until the user completes the exchange of the main tank (6) (S5), and when the exchange is completed, the process is terminated.
[0048]
In S3, if there is a remaining amount of ink in the main tank (6), the output of the first sensor (24) checks the presence or absence of the remaining amount of ink in the sub tank (5) (S6). The medium recovery sequence is performed (S7), and the process ends. The medium recovery sequence is a recovery operation for filling a certain amount of ink in the sub tank (5), and the ink suction amount is smaller than that in the large recovery sequence.
[0049]
In S6, if there is a remaining amount of ink in the sub tank (5), a small recovery sequence is performed (S8), and the process ends. The small recovery sequence is a recovery operation for refreshing the ink in the recording head (4), and the ink suction amount is the smallest.
[0050]
When the main tank (6) is replaced as described above, the suction recovery operation is not performed unless an instruction from the user is given. As described above, even if the main tank (6) is removed, the ink film formed on the filter member (14) can prevent air from entering the connection device (7), and therefore it is necessary to perform a recovery operation. Because there is no. When the user instructs the recovery operation, the flowchart of FIG. 7 is executed, and either the medium recovery sequence or the small recovery sequence is selected and executed as described above.
[0051]
Even if the remaining amount of ink in the main tank (6) runs out during printing, as described above, one page of recording paper is placed on the porous member (17) on the recording head (4) side from the sensor (27). Since more ink than the remaining amount remains, it is possible to instruct replacement of the main tank (6) after the printing is completed without interrupting the printing.
[0052]
In the above embodiment, the porous member (19) is provided in the main tank (6) so as to generate a negative pressure, but when installed below the sub tank (5) sufficiently For example, in the case where it is installed 100 mm or more below the sub tank (5), the porous member is unnecessary.
[0053]
In the above embodiment, the main tank (6) is installed below the sub tank (7), but the main tank may be installed above the sub tank.
[Brief description of the drawings]
FIG. 1 is a schematic vertical sectional view of a printing unit of an ink jet printer showing an embodiment of the present invention.
FIG. 2 is a schematic plan view of a printing unit of the ink jet printer shown in FIG.
FIG. 3 is a vertical sectional view of a portion of a sub ink tank.
FIG. 4 is a vertical sectional view of a main ink tank portion.
FIG. 5 is a vertical sectional view of a connection block portion of the connection device.
FIG. 6 is a block diagram illustrating an example of a main part of the electrical configuration of the ink jet printer.
FIG. 7 is a flowchart illustrating an example of a recovery operation.
[Explanation of symbols]
(3) Carriage
(4) Recording head
(5a) (5b) (5c) (5d) Sub ink tank
(6a) (6b) (6c) (6d) Main ink tank
(7) Connection device
(14) Filter member
(24) First ink remaining amount sensor
(27) Second ink remaining amount sensor

Claims (3)

A recording head that performs recording by discharging ink from an ejection port formed on the ejection port forming surface, a sub ink tank that is formed integrally with the recording head to supply ink to the recording head, and the recording A carriage equipped with a head and a sub ink tank, which can move a predetermined recording area and its adjacent area in the main scanning direction, a main ink tank capable of supplying ink to the sub ink tank, and the sub ink tank and the main ink tank Connecting means capable of contacting and detaching from the main ink tank, a cap member disposed in the adjacent region and capable of contacting and detaching from the discharge port forming surface of the recording head, and the cap Ink comprising suction means for sucking ink from the ejection port of the recording head via a member, and control means for controlling the suction means In jet recording device,
First ink remaining amount detecting means for detecting the presence or absence of the ink remaining amount in the sub ink tank is provided, and the control means includes a suction recovery operation at the time of initial filling in the suction means, and the first an ink jet recording apparatus, characterized in that to perform and a detection result to the result the ink suction amount two different suction recovery operation of the ink remaining amount detecting means to select one.   Second ink remaining amount detecting means for detecting the presence or absence of ink remaining in the main ink tank is provided, and the control means determines the main ink tank according to the detection result of the second ink remaining amount detecting means. 2. An ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus instructs replacement of the ink jet recording apparatus.   3. An ink jet according to claim 1, wherein a filter member for preventing air from entering the connection means when the main ink tank is detached is provided at a portion of the connection means that comes into contact with the main ink tank. Recording device.

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