JPH1134357A - Maintenance mechanism for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance mechanism for ink jet printer in which a pump and a carrying means can be driven with a small number of drive sources. SOLUTION: When a gear 141 is driven with a drive source (not shown) reversely to arrow direction at the time of maintenance, a driving force is transmitted to gears 91, 92, 157 through gears 142-150. The gears 91, 92 are meshed with a mechanism for carrying a roll paper (not shown) while the gear 157 is meshed with a grooved cam 155 for driving a pump 160. According to the mechanism, an operation for jetting ink forcibly from a head arranged at a maintenance position by driving the pump 160 and an operation for receiving the ink jetted by carrying the roll paper can be executed simultaneously with a single drive source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maintenance mechanism for an ink-jet printer, and more particularly, to a pump for applying a positive back pressure or a negative pressure to an ink ejection path, and receiving and forcibly ejecting ink from a head. The present invention relates to a maintenance mechanism including a maintenance member used for wiping a nozzle surface or the like.

[0002]

2. Description of the Related Art Conventionally, a pump for purifying the ink ejection path by applying a positive back pressure or a negative pressure to an ink ejection path of a head of an ink jet printer, and a pump for forcibly ejecting ink from the head. A maintenance member used for receiving or wiping the nozzle surface of the head, and transport means for transporting the maintenance member and changing a portion of the maintenance member facing the nozzle surface. Inkjet printer maintenance mechanisms have been considered.

In a maintenance mechanism of this type, a pump can apply a positive back pressure or a negative pressure to an ink ejection path of a head to purify the ink ejection path. Further, the ink forcibly ejected from the head by the operation of the pump or the like can be received by the maintenance member, or the nozzle surface can be wiped by the maintenance member. Further, the transporting unit transports the maintenance member and changes a portion of the maintenance member facing the nozzle surface. For this reason, the maintenance member contaminated by receiving the ink or wiping the nozzle surface is conveyed, and an unused portion of the maintenance member is opposed to the nozzle surface to perform maintenance such as receiving the ink and wiping the nozzle surface. Can always be performed well.

[0004]

However, conventionally, since the pump and the conveying means are driven by different driving sources, the structure of the maintenance mechanism is complicated, and the production cost of the ink jet printer is sufficiently reduced. Could not be reduced. Therefore, an object of the present invention is to provide a maintenance mechanism of an ink jet printer that can drive a pump and a conveying unit with a smaller number of driving sources.

[0005]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, which has been made to achieve the above object, a positive back pressure or a negative pressure is applied to an ink ejection path of an ink jet printer head. A pump for purifying the ink ejection path, a maintenance member used for receiving ink forcibly ejected from the head, or wiping a nozzle surface of the head, and the like. And a transport unit for changing a portion of the maintenance member facing the nozzle surface, wherein the pump and the transport unit are driven by the same drive source. And

[0006] In the present invention thus constructed, the pump and the conveying means are driven by the same driving source.
For this reason, the number of driving sources can be reduced, and the configuration can be extremely simplified. As a result, the manufacturing cost of the ink jet printer can be reduced favorably.

According to a second aspect of the present invention, in addition to the first aspect, the pump applies a positive back pressure to the ink ejection path when the head is disposed to face the maintenance member. It is characterized in that the purification is performed. According to the present invention, when the head is arranged to face the maintenance member, the pump applies a positive back pressure to the ink ejection path. By applying the back pressure, ink in the ink ejection path can be forcibly ejected together with dust and bubbles. At this time, since the maintenance member is arranged to face the head, the ink that has been forcibly ejected can be satisfactorily received by the maintenance member. As a method of forcibly ejecting ink, there is a method of applying a negative pressure from an outlet side (for example, a nozzle surface) of the ink ejection path. However, when the back pressure is applied, the maintenance member is easily attached to the head. Can be arranged to face each other.

Therefore, according to the present invention, in addition to the effect of the first aspect of the invention, there is an effect that the ink forcibly ejected from the head can be satisfactorily received by the maintenance member. Therefore, the surroundings can be prevented from being stained by the ejection of the ink.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the drive source simultaneously drives the pump and the transfer means. As described above, when the back pressure is applied by the pump and the ink ejected by the back pressure is received by the maintenance member, it is necessary to synchronize the pump and the transport unit. That is, the ejection amount of ink changes according to the amount of pressure applied by the pump.
Therefore, in order to better perform the ink reception, it is necessary to change the conveyance amount of the maintenance member according to the ejection amount. It is to be noted that the synchronization between the pump and the conveying means becomes particularly necessary when the amount of pressurization by the pump is changed as necessary.

In the present invention, since the pump and the conveying means are driven at the same time, both can be tuned very well. In addition, since the pump and the transfer means are driven by the same drive source, no special mechanism for tuning is required. Therefore, according to the present invention, in addition to the effect of the invention described in claim 2, there is an effect that the maintenance member can more effectively receive the ink without complicating the configuration.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a basic configuration of an inkjet printer to which the present invention has been applied. In addition,
The ink jet printer of the present embodiment is a so-called hot melt ink jet printer that melts and ejects solid ink.

As shown in FIG. 1, a head 1 of the ink jet printer is mounted on a carriage 3 (FIG. 8).
It is configured to be movable along the guide shaft 5. The head 1 forms an image by ejecting ink onto a recording paper (not shown) as a recording medium conveyed near the center of the movement range, and forms an image before and after the image formation or at a predetermined timing. The user moves to the maintenance area near the left end (the left end in FIG. 1) and receives a maintenance operation using the roll paper 7 as a maintenance member.

Next, the structure of the head 1 will be described with reference to FIGS.
This will be described with reference to FIG. 2 is an exploded perspective view of the head 1, FIG. 3 is a top view of the ink tank 10 of the head 1, and FIGS. 4 (a) and (b) are lines BB and C-
It is a C-line cut end view. Further, the configuration of the head 1 is described in detail in Japanese Patent Application No. 8-305325, which should be referred to.

The head 1 includes an ink tank 10, a front panel 30, a melting tank 40, a cam 50, and a control board stage 70, as shown in FIG. The ink tank 10 has an inclined front surface portion 15 for attaching the front panel 30 and a color output (yellow, magenta, cyan) that can store hot melt ink (hereinafter sometimes simply referred to as ink). , Black), an ink tank upper cover 19, and an ink tank heater 17 attached to the back surface of the ink tank 10, as shown in FIG. Further, a communication path 21 that opens downward is provided on the back side of the bottom surface of each of the main chamber 11 and the sub chamber 13 of the ink tank 10.

The main chamber 11 has an L-shape as viewed from above as shown in FIG. 2, and includes a main chamber entrance 21a (FIG. 4B) leading to the communication passage 21 and a front panel 30.
A main chamber outlet 22a (FIGS. 4 (a) and 2) leading to the main chamber and a filter 29 (FIG. 4 (a)) are provided. Filter 29
Is manufactured by sintering stainless steel fibers into a paper shape and then pressing the fibers. Each of the fibers is complicatedly bent and overlapped, and has a passage having a three-dimensional structure (for example, , "Tommy Firek S
S "(registered trademark): manufactured by Tomoegawa Paper Mill Co., Ltd.).

The sub-chamber 13 has a sub-chamber outlet 21b leading to the communication passage 21 and a sub-chamber inlet 22b leading to the front panel 30.
2 and 4 (b), the sub chamber outlet 21b
And a substantially inverted T-shaped valve opening / closing lever 24 which opens one of the sub-chamber inlet 22b when the other is closed.

The valve opening / closing lever 24 is made of an aluminum alloy die-cast, and as shown in FIG. 4B, a lever base 25 provided between the sub-chamber outlet 21b and the sub-chamber inlet 22b is used as a support point. It is mounted so that it can swing. Further, the valve opening / closing lever 24 is provided with pressure-contact valves 27 and 28.
By being urged by the leaf spring 26,
Normally, the pressure contact valve 28 keeps the state where the sub chamber inlet 22b is sealed. Here, the pressure contact surface of the pressure contact valve 27 has a spherical shape, the edge of the corresponding sub-chamber outlet 21b has a tapered surface shape, the pressure contact surface of the pressure contact valve 28 has a planar shape, and the corresponding port of the sub-chamber inlet 22b. The edge has an annularly protruding shape. The pressure-contact valves 27 and 28 are made of silicone rubber and have a Shore hardness of about 40 ° and a heat-resistant temperature of about 200 ° C.
It is.

As shown in FIG. 2, the ink tank upper lid 19 has a front panel cover 19a adapted to the shape of the front panel 30, a sub-chamber cover 19b for covering the sub-chamber 13, and an upper end of the valve opening / closing lever 24. A long hole 19c for exposing the portion 24a and a sub chamber 13 from the melting tank 40.
Ink inlet 1 for supplying hot melt ink to
9d, an air chamber 20 for sending compressed air from a pump 160 to be described later to each main chamber 11, a through hole 20b opened from the air chamber 20 to the side surface of the ink tank 10, and an air chamber for sealing the air chamber 20. And a lid 20a. The air chamber 20 of the ink tank top lid 19 has a through-hole 23 communicating with the main chamber 11, as shown in FIG.

As shown in FIG. 2, the front panel 30 has four nozzle heads 31 on the front surface, and a back path 35 from each main chamber 11 to each nozzle head 31 on the back surface (FIG. 4A). 4) and a return path 37 (FIG. 4B) from each nozzle head 31 to each sub-chamber 13 is formed. Further, as shown in FIGS. 2 and 4, a cover panel 30a is attached to the back surface of the front panel 30 so as to cover the outward path 35 and the return path 37, and a front panel heater 33 is provided on the back surface of the cover panel 30a. Is attached. As shown in FIG. 4, each main chamber 11 has a forward path entrance 35 a from each forward path 35, and each forward path 35 has a forward path exit 35 b from each forward path 35 to each nozzle head 31.
A return path entrance 37b is provided from 1 to each return path 37, and a return path exit 37a is provided from each return path 37 to each sub-chamber 13.

The nozzle head 31 has a piezoelectric conversion element 38, and ejects ink supplied through the outward path outlet 35b in accordance with a volume change of the piezoelectric conversion element 38. Further, the ink supplied to the nozzle head 31 can be circulated to the sub chamber 13 via the return path entrance 37b and the return path 37.

The cam 50 is mounted on the ink tank upper lid 19 so as to be slidable in the left-right direction of FIG. 3, and the vicinity of the contact surface 50a is projected rightward from above the ink tank upper lid 19. I have. The cam 50 has a cam surface 50b.
And a projection 5 provided at the left end of the cam 50.
The cam surface 50 b is normally urged by the spring 51 bridged between the protrusion 2 e and the projection 19 e provided on the ink tank top cover 19 so that the cam surface 50 b does not touch the upper end 24 a of the valve opening / closing lever 24 at normal times. keeping.

The melting tank 40 is, as shown in FIG.
The room is divided into four rooms for each color of black, cyan, magenta, and yellow, and each room has a box shape with an open top so that solid ink can be charged and stored. In addition, the lower part of each room of the melting tank
As shown in (b), a conduction path 47 for guiding the molten ink to the sub-chamber 13 is formed.

Solid ink is supplied to the melting tank 40 from an ink supply device (not shown). The melting tank 40 is provided with a heater, and the solid ink is melted by the heater.
Supply 3 Further, the control board stage 70 includes a control board (not shown), and is mounted on the head 1.

In the head 1 configured as described above, the control substrate stage 70 drives the various heaters 17, 33 and the like to hold the solid ink in a molten state, and then, based on the print data and the like, the piezoelectric substrate as described above. The conversion element 38 is driven to eject ink. Further, when moving to the maintenance area, the following purging can be executed. In addition, purging is to pressurize the ink in the front panel 30 and the nozzle head 31 from the main chamber 11 side,
Bubbles and dust in the ink that cause non-ejection are sent out of the nozzle together with the ink to the nozzle portion 31a (see FIG. 14), and those in the front panel 30 to the sub-chamber 13 to be filtered. This is an operation of filling clean ink filtered at 29. The bubbles are mixed in the ink when the temperature of the head drops when the power is turned off, the ink solidifies, and the ink is melted when the power is turned on again.
Debris may enter through the nozzle.

That is, when the head 1 moves to the maintenance area, the contact surface 50a of the cam 50 is pressed against the frame 54 (see FIG. 3) of the printer main body, and the hollow cylindrical cap 55 provided on the frame 54 is provided.
Covers the through hole 20b. Then, the cam 50 relatively slides leftward on the ink tank cover 19, and the cam surface 50b pushes the upper end 24a of the valve opening / closing lever 24 downward in FIG. Therefore, the valve opening / closing lever 24 swings around the lever pedestal 25 as a fulcrum, and the pressure contact valve 28 and the sub chamber inlet 2
When the pressure contact with 2b is released and the swinging further proceeds, the pressure contact valve 27 and the sub-chamber outlet 21b are pressed against each other, the sub-chamber inlet 22b is opened, and the sub-chamber outlet 21b is closed.

At this time, the cap 55 is
Since compressed air is supplied from a pump 160, which will be described later, through a pipe 57 connected to the hollow portion of the cap 55, bubbles can be pushed out as follows. That is, the air pressure in the main chamber 11 rises by sending the compressed air. Since the sub chamber outlet 21b is sealed, a positive back pressure is applied to the ink ejection path from the main chamber 11 to the nozzle head 31 via the outward path 35. In addition, since the sub-chamber inlet 22b is open, the ink containing air bubbles from the main chamber 11 through the filter 29,
The dust is filtered, and reaches the nozzle head 31 via the main chamber outlet 22a, the outbound entrance 35a, the outbound 35, and the outbound exit 35b. Next, the path is divided into a path that is discharged (discharged) from the nozzle portion 31a to the outside and two paths that are directed toward the return path entrance 37b. The respective flow ratios are determined by setting the flow path resistance of the outward path 35, the return path 37, and the nozzle portion 31a. The path on the return path entrance 37b side is sent to the sub chamber 13 via the return path 37, the return path exit 37a, and the sub chamber entrance 22b. As a result, the ink containing bubbles in the forward path 35, the nozzle portion 31a, and the return path 37 is replaced with clean ink.

Thereafter, the head 1 is moved to the left, and the contact surface 50a is separated from the frame 54.
Is not pressed by the cam surface 50b. Then, the valve opening / closing lever 24 swings around the lever pedestal 25 as a fulcrum by the urging force of the leaf spring 26, so that the sub chamber inlet 22b is closed and the sub chamber outlet 21b is opened. As a result, the ink forcedly sent into the sub-chamber 13 due to purging is returned from the communication path 21 to the main chamber 11, so that the liquid levels of the main chamber 11 and the sub-chamber 13 can be at the same level.

When the purging is performed, a part of the ink is forcibly ejected from the nozzle surface 36 of the nozzle head 31. In the present ink jet printer, the roll paper 7 is provided in the maintenance area. The nozzle face 36 can be wiped off by the roll paper 7 and the ejected ink can be received. Next, a maintenance unit 100 as a maintenance mechanism for transporting the roll paper 7 and pressing the roll paper 7 against the nozzle head 31 is provided.
Will be described. First, since the roll paper 7 is a consumable item, it is held in the cassette 80 shown in FIGS. 5 and 6, and after use, the entire cassette 80 is replaced or only the roll paper 7 is replaced. The supply to the user is performed by both the cassette 80 and the set of the replacement roll paper 7, and the user's convenience can be selected. FIG. 5 is a left side view showing the configuration of the cassette 80, and FIG. 6 is a longitudinal sectional view thereof.

As shown in FIGS. 5 and 6, the cassette 80
It comprises a lid 81 and a main body 82 which can be opened and closed about a hinge 80a. Inside the main body 82, a pin 83 projecting from the inner wall surface and supporting the unused roll paper 7, a fixed amount feed roller 85 for transporting the roll paper 7, and a winding shaft for winding the transported roll paper 7 87 and a pressure contact plate 89 for pressing the roll paper 7 against the nozzle head 31. The side wall of the main body 82 on which the pin 83 is formed is formed with a substantially U-shaped cut to form a spring portion 82a. For this reason, the pin 83 swings outward when the roll paper 7 is mounted, and later returns by elastic force to support the paper tube of the roll paper 7. The rotation axes of the fixed amount feed roller 85 and the take-up shaft 87 protrude from the left and right sides of the main body 82,
Gears 91 and 92 are fixed to the outside of the left side surface of the gear 2, respectively.

Further, on the side wall of the main body 82, an elongated hole 82b is formed which is substantially perpendicular to the transport path of the roll paper 7 from the outer periphery of the pin 83 to the fixed amount feeding roller 85. A pin 93a formed on the pin 93 is fitted. The press contact plate 89 includes the support portion 93 and the support portion 93.
Plate portion 95 which is swingably connected to pin 95 via pins 95a.
And a compression coil spring 97 that urges the plate portion 95 in a direction separating from the support portion 93. As shown in FIG. 5, guide pins 82c are provided on the left and right side surfaces of the main body 82.

A nip roller 98 is provided inside the lid 81.
It is provided through an oval hole 81a formed in the lid 81. When the nip roller 98 is mounted on the printer main body, the nip roller 98 receives a pressing force of a plate spring 99 provided on an upper frame of the printer main body, and is pressed against the fixed amount feeding roller 85 to sandwich the roll paper 7. Further, above the lid 81 (above in FIGS. 5 and 6), an opening 81b for projecting the roll paper 7 to the outside and an opening for detecting the amount of the roll paper 7 on the take-up shaft 87 side. 81c and the main body 82
An opening 82d for detecting the presence / absence of the roll paper 7 on the pin 83 side by a sensor 110 described later is formed below the sensor. In addition, around the opening 81b,
A notch 81d for penetrating the leaf spring 99 is also formed.

Next, FIG. 7 is a front view showing the configuration of the maintenance unit 100 when the cassette 80 is mounted, FIG. 8 is a sectional view taken along line DD, and FIG. 9 is a left side view thereof.
In FIG. 7, the press-contact plate 89 is omitted, and in FIG. 9, the side frames 102 are drawn by imaginary lines.

As shown in FIGS. 7 and 8, the maintenance unit 100 includes a pair of side frames 102 and 103. Each side frame 102 and 103 has a pin 82c.
And guides 104 and 105 for individually guiding the winding shaft 87 (FIG. 8). Guides 104, 10
When the cassette 80 is mounted along the axis 5, the movable parts 111 and 113 of the sensor 110 disposed below the
It swings around 11a and 113a. When the cassette 80 is completely mounted, the movable unit 1 on the carriage 3 side
11 comes into contact with the roll paper 7 held by the pins 83 in the cassette 80. This sensor 110 is a movable unit 1
The presence or absence of the roll paper 7 is detected based on the swing state of the roll paper 11.

The pins 93a of the pressure contact plates 89 projecting from both sides of the cassette 80 swing around the front end of the maintenance unit 100 (on the carriage 3; hereinafter, the front and rear sides are similarly defined for the cassette 80). Engaging with the tips of a pair of arms 115. Maintenance unit 100
Further, a lever 117 that swings in contact with the carriage 3 is provided further forward of the carriage 3, and the pressing plate 89 protrudes as follows according to the swing of the lever 117.

The lever 117 is connected to the maintenance unit 1
When the carriage 3 moves to the above-described maintenance area, the carriage 3 is pushed by the carriage 3 so as to be pivotable about a shaft 121 (FIG. 7) protruding forward of the position 00 and is indicated by a two-dot chain line in FIG. Rocks clockwise until Lever 11
7, a bevel gear 117a around the shaft 121 is integrally formed, and the bevel gear 117a meshes with a bevel gear 123a integrally formed on the pressing piece 123. Pressing piece 123
Are the tip of the shaft 125 projecting in parallel with the shaft 121 and the shaft 121
The lever 117 swings counterclockwise in FIG. 8 (clockwise in FIG. 9) with the swing of the lever 117. In order to clearly show the configuration of the pressing piece 123, the shaft 121 is shown in FIG. 8, and the shafts 121 and 1 are shown in FIG.
25 and the lever 117 are not shown.

The front ends of the pair of arms 115 are
The tip of the pressing piece 123 presses the iron plate 129 with the swing. As shown in FIGS. 8, 9, and 13, each arm 115 has an upper arm 131 that swings around a shaft 115a and a small-diameter portion of a key-shaped hole 131b provided substantially in the middle of the upper arm 131. Lower arm 133 that can swing around a stepped caulking pin 133b that fits
And the front end of the upper arm 131 is fixed to the left and right edges of the iron plate 129, or both are integrally formed by a single metal plate. A tension coil spring 135 is provided between the front end of the lower arm 133 and the lower end of the iron plate 129. The distal end (rear end) of the lower arm 133 is urged upward by the extension coil spring 135, and the lower end of the lower arm 133 is normally opposed to the projecting piece 131c that is bent at the lower edge of the front end of the upper arm 131. The state where the edges are in contact, that is, the upper arm 131 and the lower arm 13
3, a gap 115b is formed between the rear ends of the pin 3 such that the pin 93a just fits. Note that the tension coil spring 135 also has an action of preventing the stepped caulking pin 133b of the lower arm 133 from moving from the small-diameter portion side to the large-diameter portion side of the key-shaped hole 131b of the upper arm 131, and fits them together. maintain.

When the iron plate 129 is pressed by the pressing piece 123 as described above, the entire arm 115 is
The pressure plate 89 swings clockwise in FIG. 9 around the center 15a, and the pressing plate 89 projects together with the roll paper 7. When the pressure contact plate 89 comes into contact with the nozzle head 31 or the like with the roll paper 7 interposed therebetween, the lower arm 133 is moved to the stepped caulking pin 133b.
9 counterclockwise in FIG. 9 (clockwise in FIG. 8) against the urging force of the extension coil spring 135, so that the impact at the time of contact can be reduced. Moreover, even if each member has some error or variation in production or assembly, or even if the distance of the nozzle surface 36 from the platen is changed in accordance with the type of printing paper in order to improve the printing quality. The pressing plate 89 can be uniformly pressed against the nozzle surface 36. Further, the pressing piece 123
When no pressing force is applied, the arm 115 is held at the lowered position by the action of the leaf spring 137 (FIG. 8).

Next, a gear mechanism for driving the maintenance unit 100 will be described with reference to FIG. Gear 141 provided at the front end of maintenance unit 100
Is configured coaxially with a transport roller (not shown) for transporting the recording paper, and is rotated by receiving the driving force of the transport roller.
A gear 142 that meshes with the gear 141 is provided with a lever 142a that is bent in a dogleg shape so as to be coaxially swingable. A gear 143 meshing with the gear 142 is provided at one end of the lever 142a, and constitutes a so-called planetary gear mechanism. The other end of the lever 142a is connected to the upper arm 13
1 can be brought into contact with the contact piece 131a provided on the lower side.

The gear 141 rotates clockwise when the recording paper is transported, so that the gear 142 rotates counterclockwise and the gear 143 rotates clockwise. by this,
The lever 142a swings counterclockwise, and the gear 143
The two large and small gears do not mesh with the adjacent gear 144. FIG. 9 shows the gear 141 in this state.
143 and the movement of the lever 142a are indicated by arrows. When the lever 142a swings to the position shown in FIG. 9, it is locked by a stopper (not shown) and does not swing any further. Therefore, the driving force is not transmitted to the maintenance unit 100 while the recording paper is conveyed and the head 1 performs image formation.

When the conveying roller rotates in the reverse direction and the counterclockwise rotation is transmitted to the gear 141, the lever 142a swings clockwise. However, when the arm 115 swings downward as shown by the solid line in FIG. 9, the other end of the lever 142a comes into contact with the contact piece 131a of the upper arm 131.
The gear 143 does not mesh with the gear 144. The carriage 3 moves to the maintenance area, and moves the upper arm 131 to the position shown in FIG.
When the transport roller rotates in the reverse direction when pushed up to the position shown by the two-dot chain line, the lever 142a swings to the position shown by the two-dot chain line in FIG. 9, and the gear 143 meshes with the large diameter portion of the gear 144. That is, the driving force is transmitted to the mechanism after the gear 144 only when the carriage 3 moves to the maintenance area and the transport roller rotates in the reverse direction.

The small diameter portion of the gear 144 meshes with the gear 146 via the large diameter gear 145. The gear 146 also has a configuration in which two large and small gears are integrated.
5 meshes with the large diameter portion of the gear 146. The small-diameter portion (not shown) of the gear 146 meshes with the gear 91 exposed on the left side surface of the cassette 80 when the cassette 80 is completely mounted. The large-diameter portion of the gear 144 meshes with the gear 149 via the gears 147 and 148. The gear 149 has a configuration in which two large and small gears are integrated, as shown in FIG.
Are engaged with the large-diameter gear 150. This gear 150
Engages with the gear 92 of the cassette 80 when the cassette 80 is completely mounted (FIG. 9).

When the driving force is transmitted to the gear 144, the fixed feed roller 85 and the take-up shaft 87 of the cassette 80 integrated with the gears 91 and 92 are rotated to convey the roll paper 7. That is, the fixed amount feed roller 85 and the take-up shaft 87 correspond to a transport unit.

Further, the large-diameter portion 149b of the gear 149 meshes with a gear 157 which rotates integrally with the groove cam 155. As shown in FIG. 10, the groove cam 155 has two eccentric, substantially annular grooves 158, 159, and the pump 160 is driven by the grooves 158, 159. That is, the pump 160
A piston 161 that slides by engaging the first piston 1a with a groove 159;
And a piston 163 that slides by engaging a pin 163a with the piston 161. An intake port 165a and an exhaust port 165b are formed in a cylinder 165 in which the pistons 161 and 163 are fitted.

Therefore, when the groove cam 155 rotates, the pistons 161 and 163 slide in different phases, and the volume of the space S formed between the two increases and decreases. At this time, either the intake port 165a or the exhaust port 165b is closed by the piston 161 or 163, so that the exhaust port 165b is connected to the pipe 57 (FIG. 3).
Compressed air can be sent into the air chamber 20 of the head 1. Therefore, if the transport roller is reversed after disposing the carriage 3 in the maintenance area, the purging described above can be performed while transporting the roll paper 7.

Here, the operation of the pump 160 will be described in more detail with reference to FIG. FIG. 11 is a cross-sectional view showing the movement of the pistons 161 and 163 accompanying the rotation of the groove cam 155. When the state of FIG. 11A is set to 0 °, FIG. 155 is 120 ° in the rotation direction (counterclockwise in FIG. 11), and (C) is 1
80 ° and (D) show the rotated state at 210 °.

FIG. 11A corresponds to a state in which the exhaust is completed. The space S between the pistons 161 and 163 is extremely narrow, and the space S is open to the exhaust port 165b. When the groove cam 155 rotates to the position shown in FIG. 11B and the pistons 161 and 163 rise accordingly, the space S opens to the intake port 165a, and the preparation for starting the intake is completed. Thereafter, the piston 163 descends while the position of the piston 161 remains fixed, and the volume of the space S increases as shown in FIG. By this process, the intake port 16
Air is sucked in from 5a.

When the rotation angle of the groove cam 155 exceeds 180 °, the piston 161 also starts descending. Then, FIG.
As shown in (D), the piston 161 is connected to the intake port 165a.
And the space S moves toward the exhaust port 165b without changing its volume while being kept in a sealed state. After the space S opens to the exhaust port 165b, only the piston 161 descends as shown in FIG. 11A, so that the air in the space S is exhausted from the exhaust port 165b.

As described above, in the present ink jet printer, the same drive source as the mechanism for transporting the roll paper 7 (the above-described transport roller rotating integrally with the gear 141, and further, not shown, for driving the transport roller). The pump 160 is driven by a motor. In addition, the driving source is common to the driving source of the transport roller. For this reason, in the maintenance unit 100, the drive source can be omitted and the configuration can be extremely simplified.

As described above, in the present ink jet printer, the roll paper 7 is conveyed by the fixed amount feed roller 85 and the take-up shaft 87, but the radius of the roll paper 7 taken up by the take-up shaft 87 increases. As a result, the transport amount per rotation increases. For this reason, if the take-up shaft 87 is rotated at a constant speed during purging, the take-up speed of the roll paper 7 gradually increases, and finally, the roll paper 7 is wasted. In particular, in the ink jet printer, the take-up shaft 87 and the pump 160
Is rotated by the same drive source, and when the take-up shaft 87 and the groove cam 155 are rotated at a constant speed, the amount of ink transported by the roll paper 7 is increased by the same amount even though the amount of ink discharged by purging is the same. Will increase.

Therefore, in this ink jet printer,
With the following configuration, if the rotation speed of the groove cam 155 is constant, the transport amount of the roll paper 7 is always constant. That is, the transport amount of the roll paper 7 per one rotation by the fixed amount feeding roller 85 is kept constant all the time.
Therefore, the nip roller 98 is pressed against the fixed amount feed roller 85 to firmly sandwich the roll paper 7, and the fixed amount feed roller 85 is rotated at a constant speed to keep the transport amount of the roll paper 7 constant. Further, a so-called slip clutch (also called a torque limiter) is provided in the driving force transmission system to the winding shaft 87, and when the transport amount of the roll paper 7 by the winding shaft 87 increases, the driving force transmission system slides. Then, the rotation speed of the winding shaft 87 is reduced.

That is, the small-diameter portion 149a of the gear 149 that drives the winding shaft 87 via the gear 150 is configured as follows. As shown in FIG.
a allows the large-diameter portion 149b to freely rotate relative to the small-diameter portion 149a via a pair of felts 493 between the disk 491 provided so as to be rotatable integrally with the small-diameter portion 149a and to be movable in the axial direction. The large-diameter portion 149b is pressed and held by the elastic force of the compression coil spring 497. For this reason, when the radius of the roll paper 7 wound on the winding shaft 87 increases, tension is applied to the roll paper 7 laid between the fixed amount feeding roller 85 and the outer periphery of the winding shaft 87, and the tension is reduced. The small diameter portion 149a and the felt 493 or the felt 493 and the large diameter portion 149
and a slippage occurs with b. Therefore, the rotation speed of the take-up shaft 87 can be adjusted to a rotation speed corresponding to the transport amount of the fixed amount feed roller 85, and the roll paper 7 can be transported at a constant speed.

As described in detail above, the configuration of the maintenance unit 100 can be extremely simplified by omitting the drive source. For this reason, in the present ink jet printer, the manufacturing cost can be favorably reduced. When purging is performed by driving the pump 160, the roll paper 7 contacts the lower end of the nozzle head 31 as described above. Therefore, the ink ejected from the nozzle surface 36 due to the purging can be satisfactorily received by the roll paper 7. Therefore, it is possible to satisfactorily prevent the periphery of the maintenance unit 100 from being stained by the ejection of the ink due to the purging.

Further, the transport amount of the roll paper 7 is determined by the groove cam 15.
5 is maintained at a constant value corresponding to the rotation speed of the roller 5, and the conveyance of the roll paper 7 and the driving of the groove cam 155 are simultaneously performed. For this reason, in the maintenance unit 100, the conveyance of the roll paper 7 and the driving of the pump 160 can be tuned well without using a special configuration. Therefore, the groove cam 1
Even when the amount of pressurization by the pump 160 is changed by changing the rotation speed of 55, the roll paper 7 can be transported at a speed corresponding to the amount of pressurization. That is, if the amount of pressurization changes, the amount of ink ejected from the nozzle surface 36 also changes, and the roll paper 7 necessary to receive the ink changes.
Also varies. In the maintenance unit 100, since the transport amount of the roll paper 7 is synchronized as described above,
The ink can be received more favorably without complicating the configuration.

Further, in the above embodiment, when the carriage 3 is not moved to the maintenance area, the pump 160, the fixed amount feed roller 85, and the winding shaft 87 are brought into contact by the contact between the contact piece 131a and the lever 142a. The driving force is not transmitted to the motor. That is, the head further includes a prohibition unit that prohibits transmission of the driving force to the pump and the conveyance unit when the head is not disposed at a predetermined position for performing maintenance. For this reason, even though the carriage 3 is not moved to the maintenance area, the purging is performed, and the periphery of the maintenance unit 100 is soiled, and even though the roll paper 7 is not in contact with the nozzle head 31, It is possible to prevent the paper 7 from being transported and the roll paper 7 from being wasted.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, as the maintenance member, in addition to the roll paper 7, a nonwoven fabric or the like may be used, and a member used for maintenance other than receiving ink and wiping the nozzle surface may be used. In addition, the wiping of the nozzle surface includes rubbing the maintenance member relatively with the nozzle surface in contact with the nozzle surface, and simply contacting the maintenance member with the nozzle surface. Further, the pump may purify the ejection path by sucking the ink from the nozzle surface side. However, in this case, it is difficult to perform suction while the maintenance member is in contact with the head. Therefore, in order to use the same driving source, the transmission of the driving force is switched to a conveyance means or a pump by a planetary gear mechanism or the like, and suction is performed on one of the adjacent nozzle surfaces, and the other nozzle surface is suctioned. On the other hand, the maintenance member may be brought into contact with the maintenance member. In the latter case, the transport means and the pump can be driven simultaneously.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a basic configuration of an ink jet printer to which the present invention has been applied.

FIG. 2 is an exploded perspective view illustrating a configuration of a head of the inkjet printer.

FIG. 3 is a top view illustrating a configuration of an ink tank of the head.

FIG. 4 is a BB line and C showing the configuration of the ink tank.
FIG. 4 is a sectional view taken along the line C.

FIG. 5 is a left side view showing a configuration of a cassette for maintenance of the head.

FIG. 6 is a longitudinal sectional view showing the configuration of the cassette.

FIG. 7 is a front view illustrating a configuration of a maintenance unit when the cassette is mounted.

FIG. 8 is a diagram showing a configuration of the maintenance unit DD.
It is a line sectional view.

FIG. 9 is a left side view illustrating the configuration of the maintenance unit.

FIG. 10 is a right side view illustrating a configuration near a pump of the maintenance unit.

FIG. 11 is an explanatory diagram illustrating an operation of a pump of the maintenance unit.

FIG. 12 is an explanatory diagram illustrating a configuration of a slip clutch of the maintenance unit.

FIG. 13 is an exploded perspective view illustrating a configuration of an arm of the maintenance unit.

FIG. 14 is an explanatory diagram illustrating a configuration of a flow path of a nozzle head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Head 3 ... Carriage 5 ... Guide shaft 7
... Roll paper 10 ... Ink tank 20 ... Air chamber 20b ... Through hole 31 ... Nozzle head 35 ... Outgoing path 36 ... Nozzle surface 37 ... Return path 55
... Cap 57 ... Pipe 80 ... Cassette 85 ... Fixed feed roller 87 ... Winding shaft 89 ... Pressing plate 100 ... Maintenance unit 155 ... Groove cam 160 ... Pumps 161 and 163
... Piston 493 ... Felt 497 ... Compression coil spring

Claims (3)

[Claims] A pump that applies a positive back pressure or a negative pressure to an ink ejection path of an ink jet printer head to purify the ink ejection path; and receives ink forcibly ejected from the head.
An inkjet head comprising: a maintenance member used for wiping a nozzle surface of the head; and transport means for transporting the maintenance member and changing a portion of the maintenance member facing the nozzle surface. A maintenance mechanism for a printer, wherein the pump and the transport unit are driven by the same drive source. 2. The ink-jet apparatus according to claim 1, wherein the pump performs the cleaning by applying a positive back pressure to the ink ejection path when the head is disposed to face the maintenance member. Printer maintenance mechanism. 3. The maintenance mechanism according to claim 2, wherein the driving source drives the pump and the transporting unit simultaneously.