JP2756337B2 - Ink jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus that forms a desired image by discharging ink.

[Conventional technology]

Conventionally, in a serial ink jet recording apparatus, there is a type in which a drive is directly transmitted from a motor to a cap member opening / closing mechanism performed on an ink discharge port forming surface of a recording head, and the cap is moved back and forth to press the cap against the head. Was. On the other hand, the applicant of the present invention has proposed that the cap itself is opened and closed without connecting a drive source by using the movement of the carriage, as disclosed in Japanese Patent Application Nos. 1-226322 and 1-226323.
No. proposed. According to this proposal, since there is no drive source on the cap side, there is an advantage that the size and cost can be easily reduced as compared with the above-mentioned one.

[Problems to be solved by the invention]

However, in the configuration in which the cap is opened and closed by moving the carriage, the recording head moves from the non-recording area to the recording area when recording is performed. However, it is necessary to surely open the cap at that point, so the cap is opened. It is necessary to increase the elastic force of the spring for this purpose. For this reason, there were the following disadvantages. That is, if the elastic force of the spring is increased when closing the cap, it is necessary to use a motor having a large power for the carriage drive motor, which leads to cost increase and an increase in the size of the apparatus.

Also, in order to maintain the closed state of the cap, it is necessary to always excite the carriage drive motor.However, if the elastic force of the spring for opening the cap is increased, the motor is not energized during excitation. Fever can be a problem.

In some cases, a rubber (elastic body) projection is provided on a member fixing the cap to open and close and hold the cap.

In this configuration, the rubber is pressed against a part of the head on the carriage, so that the rubber projection may touch the ink ejection port of the head when opening and closing the cap. If the rubber projection hits the nozzle, the ink may not be ejected or may be distorted. Also, by using rubber,
A change in rubber hardness due to a change in temperature or a change over time may cause a problem in the reliability of opening and closing and holding the cap.

SUMMARY OF THE INVENTION The present invention has been proposed to solve these problems, and an object of the present invention is to provide an ink jet recording apparatus capable of performing a reliable opening and closing operation of a cap and performing excellent ejection recovery.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a recording head having a discharge port surface provided with a discharge port for discharging ink, and a recording area where recording is performed by the recording head and a recording area where the recording area is recorded. A carriage for moving the separated non-recording area, a cap member provided in the non-recording area to cover the ejection port surface, and a cap member along the moving direction of the carriage in the non-recording area. A rail provided on the back, comprising: a concave engaging portion on the carriage side; and a protruding engaging portion capable of engaging with the concave engaging portion on the cap member side. The cap member is moved along the moving direction in conjunction with the movement of the carriage, and the rail presses the cap member in accordance with the movement of the cap member, whereby the cap is moved. When the carriage is moved in a direction opposite to the moving direction from the state in which the ejection port surface is covered with the material and the concave engaging portion and the projecting engaging portion are engaged with each other. An ink jet recording apparatus is provided, wherein the cap member is pressed in the opposite direction by the carriage by the engagement between the concave engagement portion and the projection engagement portion.

According to the present invention, a projection is provided on a part of the cap member, and a cutout for engaging with the projection is provided on the carriage on which the recording head is mounted, so that the carriage can be opened when the cap is opened. It is configured to press the cap in the opening direction at the cutout part, so the spring force used to open the cap is reduced, the load on the carriage motor is reduced, and the cap is opened and closed reliably. Can be.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a recording head having a plurality of discharge ports for discharging ink droplets according to a recording area, 2 denotes a carriage mounted with the recording head 1 and moved in the main scanning direction, and 3 denotes a carriage 2 which slides. A carriage shaft movably supported, 4 is a recording medium to be recorded, and 5 is a feed roller that conveys the recording medium 4 according to a recording situation.

Reference numeral 6 denotes a feed roller 5 and a pulse motor serving as a drive source for performing automatic paper feeding. Reference numeral 7 denotes a pump carriage capable of recovering the cap unit and moving parallel to the carriage shaft 3. Reference numeral 8 denotes a guide for guiding the parallel movement of the pump carriage. The shaft 9 is a return spring for urging the pump carriage 7 rightward in the figure. The pump carriage 7 is provided with an arm portion 7a, and a distal end portion thereof is provided with a hole 7b into which a projection 2a provided on the right side of the carriage 2 can be fitted. The projection 2a is fitted into the hole 7b when the carriage 2 moves to the left, and the cap 17 is inserted into the ejection surface of the recording head 1.
, The carriage 2 is prevented from rotating in the vertical direction.

As shown in FIG. 2, one end of a leaf spring 10 having elasticity in the carriage traveling direction is fixed to a rear portion of the pump carriage 7. Further, the other end of the leaf spring 10 is held so as to be sandwiched by a slide gear support 12 that supports the slide gear 11. Further, the slide gear support 12 is provided so as to be movable in the carriage running direction along the slide shaft 13. Therefore, the slide gear 11
Is stopped at a position pressed by the elastic force of the leaf spring 10.
Therefore, the carriage 2 moves, and the projection 2a of the carriage 2 comes into contact with the arm portion 7a of the pump carriage 7 and moves integrally, so that the slide gear 11 moves in the carriage traveling direction.

As shown in FIG. 3, the slide gear 11 meshes with a gear that rotates independently and in parallel with the carriage traveling direction. In the figure, 14 is a feed gear for transmitting driving force to the paper feed gear,
Reference numeral 15 denotes an ASF gear for transmitting a driving force of an automatic sheet feeder (hereinafter ASF) paper feed, and reference numeral 16 denotes a pump gear for transmitting a driving force to a suction recovery device. The pump gear 16 is formed by integrating two gears, and the left gear 16b is engaged with a pump cam 28 of the suction recovery device. Therefore, the slide gear 11 meshes with one of the gears 14, 15, 16 via the pump carriage 7 and the leaf spring 10 depending on the stop position of the carriage 2, so that the driving force of the pulse motor 6 can be selectively transmitted. Have been.

FIG. 4 is a sectional view showing details of the capping unit.

The cap 17 is formed by using an elastic member such as rubber which presses the outer edge of the discharge surface of the head with an elastic force, and has a vent 17a and a driving space 17b. The cap 17 is supported by a cap holder 18, and this cap holder 18 is held by a holder 19. On the back surface of the cap holder 18, there is formed a projection 18a having a rod-like shape and a leading end portion penetrating the rear wall of the holder 19, and the coil spring 20 is fitted on the projection 18a. Further, an E-ring 21 for restricting the movement of the cap holder 18 in the head direction is attached to the tip of the projection 18a. The cap holder 18 can be moved in the left-right direction of the drawing by a guide (not shown) provided on the holder 19 with respect to the holder 19, and the holder 19 is provided on the pump carriage 7 with respect to the pump carriage 7. The guide is movable left and right in the figure by a guide (not shown).

A groove 19b is provided in the rear part of the holder 19, and the rail 22 is inserted into the groove 19b. The rail 22 is vertically divided into two parts (in this case, the rails 22a and 22b only need to move independently, and may be independent of each other, or one rail may be divided into two parts). ,
The lower rail 22b is used to move forward and backward with respect to the recording head 1, and the upper rail 22a is used to open and close the air release valve 23. A rail arm portion 22c is provided at the back of the rail 22, and a rail dowel portion 22d is provided at a distal end thereof. The rail 22 is fixed to a pump base 25 as shown in FIG.

At the back of the holder 19, an atmosphere release valve 23 is provided, which is urged by a spring 24 to the left in the figure.
Therefore, the atmosphere release valve 23 is movable in the left-right direction in the figure along the rail 22a.

The atmosphere release valve 23 is fixed by inserting the holder 19 from above. The air release valve 23 is a cap.
The space 17b is located in front of the vent 17a provided in the 17, and by closing the vent 17a with the atmosphere release valve 23, the space 17b can be sealed. Further, an ink absorber 69 is provided at the bottom of the cap 17 to absorb and hold the ink when sucking the ink and prevent the nozzle from drying during the capping.

As will be described in detail with reference to FIG.
On the side surface of, there is provided a protruding engaging portion which engages with a cutout (recessed engaging portion) on the carriage side which will be described in detail with reference to FIG.

The rail 22 is formed of an elastic body, and has a shape protruding toward the recording head 1 in the direction of the drawing as shown in each drawing of FIG. 7 when viewed from above the printer. Therefore, the projection 2a of the carriage 2 comes into contact with the arm portion 7a of the pump carriage 7, the pump carriage 7 and the carriage 2 move integrally, and the holder 19 and the atmosphere release valve 23 are moved.
Moves along the shape of the rail 22, and the cap 17 is pressed against the head discharge surface at the stage of FIG. 7 (b).

First, when the carriage 2 is within the printing range as shown in FIG. 1, the pump carriage 7 is urged by the return spring 9 and comes into contact with the side surface of the pump base 25 as shown in FIG. ing. In this state, the cap 17 is in a positional relationship so as not to overlap with the recording head 1, and the air release valve 23 does not close the ventilation port 17a.

Next, the carriage 2 moves to the left beyond the printing range,
When the projection 2a comes into contact with the arm 7a and further moves to the left, the atmosphere release valve 23 and the holder 19 move along the rails 22a and 23b, and when the carriage 2 moves to the position shown in FIG. The cap 17 comes into pressure contact with the discharge surface of the recording head 1.
At the same time, the projection-like engaging portion 19a on the cap side and the concave engaging portion 2b on the carriage side are also engaged. The pressing force at this time is about 300 g due to the spring 20. At this time, as shown in FIG. 7 (b), the position where the holder 19 is in contact with the rail 22 and the position where the air release valve 23 is in contact with the rail 22 are determined by the distance between the rail 22 in the longitudinal direction. Since the rails 22a and 22b are displaced by the same distance, the air release valve 23 does not go up the rail 22a even if the rising angle and the changing position of the rail 22 are the same, and the vent 17a of the cap 17
Is not closed, the space 17b between the cap 17 and the recording head 1 is in communication with the atmosphere, and the recording head 1 is not pressurized by the capping, so that there is no non-discharge due to meniscus retreat at the discharge port. .

Further, when the carriage 2 moves to the left and the air release valve 23 has completely climbed the rail 22a, the air release valve 23 is moved to the cap 17 position.
Is closed, and the space 17b is closed. When the carriage 2 further moves leftward from this state to reach the position shown in FIG. 7C, the slide gear 11 meshes with the pump gear 16, and the suction recovery device operates. At this time, FIGS.
As shown in the figure, the suction tube 26 is connected to the cap 17 and the other end is connected to the cylinder 27 as shown in FIG. 5, so that the negative pressure generated in the cylinder 27 causes the suction tube 26 to Through the space 17b.

When the carriage 2 is located at the position shown in FIG. 7 (d), the rotational force of the pulse motor 6 is sequentially transmitted to the pump gear 16 → the gear 16 → the gear of the pump cam 28 to the suction recovery device. The pump cams 28 and 29 are integrated with a positioning dowel (not shown) and are rotatable with respect to the pump cam shaft 30. As shown in FIG. 6, the opposing surfaces of the pump cams 28 and 29 are provided with elliptical grooves so that both ends of the parallel pin 32 integrally connected to the piston 31 can slide. , The parallel pin 32 moves up and down, causing the piston 31 to move up and down.

Further, as shown in FIG. 5, the pump cam 29 is provided with a projection 34 for pushing down one end of the pump flag 33, and the pump flag 33 can rotate around the guide shaft 8 as a rotation center. Also, the other end 33 of the pump flag 33
The opposing position of a (at the bottom of the carriage 2 shown in FIG. 1)
In addition, a transmission sensor 35 is provided. While the projection 34 is rotating and abutting against one end of the pump flag 33, the other end
33a blocks the light beam transmitted from the light-emitting part of the transmission sensor 35 to the light-receiving part. By controlling the number of pulses of the pulse motor 6 from the time of the cut-off, the position control of the suction recovery device becomes possible.

When the projection 34 further rotates from this state and comes off one end of the pump flag 33, the pump flag 33 reversely rotates around the guide shaft 8 by its own weight or the elastic force of a spring. The other end 33a of the pump flag 33 can transmit the light beam emitted from the transmission sensor 35. The rotation of the pump flag 33 is stopped by a stopper (not shown) provided on the pump base 25. On the right side of the pump cam 28,
A cam 28b for guiding the dowel portion 22d of the arm 22c provided on the rail 22a and a cam (not shown) for guiding the rubbing lever 36 are provided. Rub lever 36 is pump base
25, and is rotatable with respect to the recording head 1. The rear part of the rubbing lever 36 is provided on the right side surface of the pump cam 28 and is guided by a cam (not shown). When riding on this cam, the rubbing member 36 is rotated, and a rubbing member 37 (provided on the right side of the rubbing lever 36, For example, an ether-based polyurethane continuous pore body is used as the material) so that the recording head 1 can be advanced to a position where it overlaps with the recording head 1.
Then, with the rubbing member 37 advanced, the carriage 2
Is moved from left to right until it comes to the front of the rubbing member 37, the ink, impurities, etc. on the ejection surface of the recording head 1 are removed, and the ejection stability of the recording head 1 is secured. The pressing force of the rubbing member 37 against the recording head 1 is determined by using the elastic force of the rubbing member 37 itself or separately.
(The pressing force is, for example, about 100 g).

As shown in FIGS. 5 and 6, a projection 28c is provided on the upper part of the pump cam 28, and the projection 28c is
By pressing the rear portion 19, the rail 22b and the cap 17 are elastically deformed, introducing air into the discharge port, and removing microbubbles, which is one of the causes of printing failure. These fine bubbles are discharged out of the head together with the large bubbles formed by air introduction. Also, the cam 28b is located on the dowel portion 22 of the arm 22c.
When released from d, the rail 22a releases the pressing of the air release valve 23, the air release valve 23 is pushed back by the elastic force of the spring 24, and the air is introduced into the cap 17 which has been sealed up to that time. .

Further, a wiper 38 is provided on the right side plate of the pump base 25 in order to secure the ejection stability of the recording head 1. The wiper 38 is, for example, a silicon rubber plate having a thickness of 0.3 mm, and always overlaps the recording head 1 (the amount of overlap is, for example, 1.0 mm).
Has been fixed to be. Thereby, the recording head 1
When the paper passes in front of the wiper 38, the discharge surface is always wiped off, so that paper dust, dust, ink residue, and the like adhering to the discharge surface are removed.

FIG. 8 is a perspective view of a carriage according to the present invention. Reference numeral 2b denotes a cutout portion that engages with a projection of a member that opens and closes the cap. 1a is a nozzle for discharging ink. In the figure, the x direction is the paper feed direction (parallel to the nozzle),
The y direction is the direction in which the carriage scans. At this time,
It is desirable that the cutout portion 2b is not at the same height as the nozzle 1a in the x direction. This is because the projection of the member for opening and closing the cap does not hit the nozzle.

FIG. 9 is a perspective view of a cap according to the present invention.
A projection 19a is provided on a member (holder 19) for opening and closing the cap. As described above, it is desirable to provide the projections 19a at different positions in the x direction in the drawing from the cap 17 that contacts the head. Note that the arm 7a is omitted.

10 and 11 are views showing the positional relationship between the projection 19a and the cutout 2b in the present invention from above in the x direction in FIG.

FIG. 10 shows a state in which the cap is open. protrusion
19a is located at a position where it does not hit the cutout 2b.

Eleventh, the cap is pressed against the head, and the cap is closed. The cap 17 is pressed against the head 1 by the movement of the carriage 2. At this time, the projection 19a has penetrated the cutout 2b in the x direction as shown in the figure.
In the y direction, it is desirable to provide a slight gap of about 0.1 to 1 mm so that the operation can be performed smoothly.

When the cap is opened by moving the carriage carrying the recording head in the direction indicated by arrow A in FIG.
The carriage 2 moves in the y direction in FIG. Also the rail 22b and the holder 19 at this time is subjected to such some resistance, the protrusion 19a side 19a ₁ and oyster portion engaged with the side surface 2b ₁ and 2b cut in, reliably can open the cap 17 from the head . At this time, when the protrusion 19a is an elastic body such as rubber, if the above-described resistance is larger than the rubber elasticity, the carriage 2 moves in the y direction while rubbing the cap, and fails to open the cap. I will.

The amount of overlap between the projection 19a and the cutout 2a is
It is desirable that the cap 17 be pushed more than the head 1. This is because, when the cap is opened, even after the cap is completely opened, the projection 19a and the cutout 2a are engaged, so that the cap does not rub against the head.

The present invention provides an excellent effect particularly in a recording head and a recording apparatus of a bubble jet system among the ink jet recording systems.

Regarding the representative configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, heat energy is generated in the electrothermal transducer, and the recording head This is effective because it is possible to form a bubble in the liquid (ink) by one-to-one correspondence with the drive signal as a result of film boiling on the heat-acting surface. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. This pulse-shaped drive signal is disclosed in U.S. Pat. No. 4,463,359.
No. 4,434,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the invention relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As a configuration of the recording head, in addition to the combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in each of the above-mentioned specifications, a heat acting section A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which the is bent, is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters.
The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461/1984, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge portion.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be reduced by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration that satisfies the above or a configuration as a single recording head that is integrally formed may be used, but the present invention can more effectively exert the above-described effects.

In addition, a replaceable chip-type recording head that can be electrically connected to the device main body and supplied with ink from the device main body by being attached to the device main body, or provided integrally with the recording head itself The present invention is also effective when a cartridge type recording head is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like, which are provided as components of the printing apparatus of the present invention, since the effects of the present invention can be further stabilized. To be more specific, a capping unit, a cleaning unit, a pressure or suction unit, a preheating unit using an electrothermal converter, another heating element, or a combination thereof, for the recording head. Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

Further, the printing mode of the printing apparatus is not limited to the printing mode of only the mainstream color such as black, but may be a printing head integrally formed or a combination of a plurality of printing heads. The present invention is extremely effective for an apparatus having at least one of the full colors.

〔The invention's effect〕

As described above, by using the present invention, the opening and closing of the cap, particularly, the operation of opening the cap can be reliably performed. Therefore, the pump carriage 7 can be smoothly moved in the recording area direction, and the spring force of the return spring 9 can be reduced. Therefore, the power of the carriage drive motor can be reduced, and the size of the apparatus can be reduced. In addition, since the operation of opening the cap can be reliably performed, the cap does not rub the ejection opening of the head, so that the head is not damaged and the print quality is not deteriorated.

That is, according to the present invention, a projection is provided on a part of the cap member, and a cutout for engaging with the projection is provided on the carriage on which the recording head is mounted, so that the carriage can be opened when the cap is opened. Since the configuration is such that the cap is pressed in the opening direction at the cutout portion, the spring force used to open the cap is reduced, the load on the carriage motor is reduced, and the cap can be opened and closed reliably. An ink jet recording apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a liquid jet recording apparatus according to the present invention, FIGS. 2 and 3 are perspective views of a gear mechanism for explaining switching between paper feed drive and cap drive, and FIG. 4 is capping. FIGS. 5 and 6 are perspective views showing details of the suction recovery device, and FIGS. 7 (a) to 7 (d) are capping and air release valves.
FIG. 8 is a plan view for explaining the operation of 23, FIG. 8 is a perspective view of a carriage according to an embodiment of the present invention, FIG. 9 is a perspective view of an embodiment of the cap unit, FIG. 10 and FIG. It is a figure showing operation. 1 Head 1a Nozzle 2 Carriage 2b Cutting part 7 Pump carriage 9 Return spring 17 Cap 18 Cap holder 19 Holder 19a Projecting part 20 Cap spring 22b …… Rail

Claims (2)

(57) [Claims] A recording head having a discharge port surface provided with a discharge port for discharging ink, and moving between a recording area where recording is performed by the recording head and a non-recording area deviating from the recording area. A cap member provided in the non-recording area to cover the discharge port surface, and a rail provided on the back of the cap member along a moving direction of the carriage in the non-recording area. A concave engaging portion is provided on the carriage side, and a protruding engaging portion capable of engaging with the concave engaging portion is provided on the cap member side, in conjunction with the movement of the carriage. The cap member moves along the moving direction, and the rail presses the cap member in accordance with the movement of the cap member. When the carriage is moved in the direction opposite to the moving direction from the engaged state, the concave engagement portion and the projection engagement portion are engaged with each other. The ink jet recording apparatus according to claim 1, wherein the cap member is pressed by the carriage in the opposite direction by engagement with the protruding engagement portion. 2. The recording head according to claim 1, wherein the recording head is provided with an electrothermal converter for generating thermal energy used for discharging ink by causing a film boiling phenomenon in the ink. Ink jet recording device.