JP2001026113A - Ink jet recording device - Google Patents

Abstract

(57) Abstract: Provided is an ink jet recording apparatus having an alignment mechanism capable of sealing all nozzle openings of a recording head mounted on a carriage with a cap member. SOLUTION: A cap frame 25 capable of moving forward and backward toward a carriage 1 is provided with a cap holder 24 capable of moving forward and backward by a predetermined amount and movably in a horizontal direction, and cap members 21, 22, 23 are provided on the cap holder 24. Accommodation holes 30, 31, 32 for accommodating, and an inclined surface 3 slidably contacting the positioning guide 15 of the carriage 1 when moving forward
A guide projection 34 having 4a and 34b is provided.
Further, cap springs 26, 2 for urging the cap holder 24 in the forward direction via the cap members 21, 22, 23.
The capping device 20 is configured by providing the capping device 7 and 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having an ink jet recording head moving in the width direction of a recording sheet, and printing an image by ejecting ink droplets onto the recording sheet in accordance with print data. More specifically, the present invention relates to an ink jet recording apparatus provided with a capping device capable of accurately sealing a nozzle opening of a carriage returned to a home position by a positioning unit.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years, since noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus is provided with an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and moves the recording head on a carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving it in the width direction of the recording paper.

On the carriage, a recording head capable of discharging black ink and each color ink of yellow, cyan, and magenta is mounted, and by changing not only the text printing with black ink but also the discharge ratio of each ink, Enables full-color printing.

The above-mentioned ink jet recording head is
Since the ink pressurized in the pressure generating chamber is ejected from the nozzles as ink droplets onto the recording paper to perform printing, the ink viscosity increases due to evaporation of the solvent from the nozzle openings, the ink solidifies, and dust is generated. There is a problem that printing failure occurs due to adhesion and furthermore, mixing of bubbles.

[0005] For this purpose, the ink jet recording apparatus is provided with a capping device for sealing the nozzle opening of the recording head during non-printing and a wiping member for wiping and cleaning the nozzle forming surface as required. I have. The capping device not only functions as a lid that prevents drying of the ink at the nozzle openings when printing is suspended, but also
When clogging occurs in the nozzle opening, the nozzle forming surface is sealed by a capping device, and the ink is suctioned and discharged from the nozzle opening by negative pressure from a suction pump as a negative pressure generating means, and the nozzle is solidified by ink. It also has a function of eliminating ink ejection failure due to clogging of the openings and mixing of bubbles into the ink flow path.

The process of forcibly discharging and sucking ink for eliminating clogging of the recording head and mixing of air bubbles into the ink flow path is called a cleaning operation. This is executed when printing is resumed after a long pause, or when the user recognizes that the quality of the recorded image has deteriorated, and operates, for example, a cleaning switch. After that, the process involves a wiping operation of the nozzle forming surface of the recording head with a wiping member formed of an elastic plate such as rubber.

[0007] The recording head also has a function of applying a drive signal unrelated to printing to eject ink droplets. This function is called a flushing operation, and the recording head is wiped by a cleaning operation. To recover the irregular meniscus generated near the nozzle opening,
In addition, it is possible to discharge the mixed color ink flowing backward from the nozzle by the wiping action, and to execute the ink jetting at regular intervals in order to prevent clogging due to thickening of the ink at the nozzle opening where the ink droplet ejection amount is small during printing. is there.

[0008]

By the way, as described above, in the conventional ink jet recording apparatus, when the carriage carrying the recording head returns to the home position, it is pressed by the carriage or the capping apparatus. The driving unit moves from the non-capping position (the non-sealing position of the nozzle forming surface) to the capping position (the nozzle forming surface sealing position), and moves the cap member mounted on the capping device with respect to the nozzle forming surface of the recording head. The nozzle opening of the recording head is sealed by elastic contact with a spring.

However, there is some variation in the stop position of the carriage that has returned to the home position. In addition, since the capping device is assembled with a large number of components, the accuracy of each component and the assembly accuracy may vary. Variations also occur.

[0010] For this reason, the positional relationship between the nozzle forming surface of the recording head mounted on the carriage and the cap member advancing toward the nozzle forming surface is shifted. Therefore, the sealing surface formed at the tip of the cap member cannot seal the entire nozzle opening, and a part of the nozzle opening comes into contact with the sealing surface, or a part of the nozzle opening comes off the sealing surface. Therefore, there arises a problem that the entire nozzle opening cannot be sealed by the cap member.

In the above situation, even if the cleaning operation is performed, it becomes difficult to suck and discharge the ink from some of the nozzle openings, which causes a problem that a printing failure occurs immediately. Further, in the capping state during the suspension of the recording apparatus, a part of the nozzle opening is exposed from the cap member and the ink solvent volatilizes, so that the solidification proceeds from the nozzle opening to the ink flow path in the recording head,
In many cases, this leads to a problem that makes it difficult to recover.

In order to avoid such a problem, it is preferable to provide a centering mechanism for matching the positional relationship between the nozzle forming surface and the cap member in the capping state. However, this centering mechanism operates smoothly and The centering action must be reliable and the structure must be as simple and inexpensive as possible.

The present invention has been made in view of such technical problems, and has a simple structure, can perform a smooth operation, and the cap member can reliably seal all nozzle openings. It is an object of the present invention to provide an ink jet recording apparatus provided with capping means.

[0014]

In order to achieve the above-mentioned object, an ink jet recording apparatus according to the present invention is provided by mounting a recording head having nozzle openings on a carriage moving in the width direction of recording paper. An ink jet recording apparatus that forms an image on recording paper by ejecting ink droplets from the nozzle openings while the carriage is moving, wherein the carriage is disposed at a home position outside a print area by the recording head, and the carriage is at the home position. In the restored state, a cap frame arranged so as to be able to advance and retreat toward the recording head, a driving means for driving the cap frame in the advance and retreat direction, and a reciprocating mechanism so that the cap frame can advance and retreat by a predetermined amount. Engagement is provided so as to be movable in a direction orthogonal to the reciprocation direction,
A cap holder having a guide projection which abuts a part of the carriage when the carriage advances and the position in the orthogonal direction is centered, and a nozzle opening which is accommodated in the cap holder and the cap frame advances when the cap frame advances. It is characterized by comprising a cap member for sealing, and an urging member for pushing the cap holder in the forward direction via the cap member.

According to the ink jet recording apparatus having the above-described structure, when the carriage returns to the home position, the cap frame at the standby position, which has been retracted, is advanced by the operation of the driving means, and the cap holder is moved forward with the cap frame. The cap holder is aligned with the recording head by the guide projection abutting on the carriage. Then, by the above-described centering action of the cap holder, the cap member is brought into a concentric state with the nozzle forming surface, and in this state, the cap member seals the nozzle forming surface.

The cap holder is provided with a plurality of through holes, and limits the amount of advance and retreat of the cap holder to upright columns which are erected on the cap frame and fit loosely into the plurality of through holes, respectively. With the configuration in which the stopper surface is arranged, the cap holder is brought into contact with the stopper surface while being aligned with the advance of the cap frame, and is brought into close contact with the cap frame.

Further, when the guide projection is inserted into a positioning guide provided on the carriage, it is preferable that an inclined surface for slidingly contacting the positioning guide and aligning the cap holder is formed. . With this configuration, when the inclined surface of the positioning guide abuts the positioning guide of the carriage, a component force for moving the cap holder in the alignment direction is generated by the abutting force, and the cap holder is smoothly aligned and the cap member is adjusted. An appropriate positional relationship between the nozzle and the nozzle opening can be formed.

Preferably, a gap is formed between the through hole and the upright column, the gap being larger than the centering amount of the cap holder. With this configuration, the centering operation can be smoothly performed without being restricted by the positional relationship between the through hole and the upright pillar during the centering of the cap holder.

Further, a taper pin is provided upright on one of the cap member and the cap holder, and the other is provided with a taper hole for centering the cap member into which the taper pin fits when the cap member comes into contact with the cap holder. Is desirably provided.

With this configuration, the cap member pressed against the cap holder by the urging member is correctly centered on the cap holder. Therefore, when the cap holder is aligned in this state, the cap member and the nozzle opening are set in an optimal positional relationship.

Further, the driving means can be constituted by a float spring for urging the cap frame in the forward direction and a cam member having a cam surface for pushing the cap frame in the direction opposite to the urging. The urging force of the float spring may be greater than the urging force of the cap spring. With this configuration, the cap frame smoothly advances and retreats by a predetermined amount, and when the cap frame advances, the cap member can seal the nozzle forming surface of the recording head with an appropriate pressure.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 shows the overall configuration of a recording apparatus to which the present invention is applied. Reference numeral 1 denotes a carriage, which is connected to a timing belt 2 which reciprocates by a drive motor 3 and is guided by a guide member 4 so as to reciprocate along the longitudinal direction of a platen 5. ing.

A recording head 7 for discharging black ink and recording heads 8 and 9 for discharging color inks such as yellow, cyan, and magenta are provided on a surface of the carriage 1 facing the recording paper 6. Each of the recording heads 7, 8, and 9 receives ink supplied from the ink cartridges 10, 11, and 12 and discharges ink droplets from the nozzle openings onto the recording paper 6, so that characters and patterns are printed. Is configured.

Reference numeral 20 denotes a capping device,
Nozzle forming surfaces 7a, 8 of recording heads 7, 8, 9 described later
a, 9a, and cap members 21, 22, 23 having a size capable of sealing the nozzle opening in a sealed space by contacting the nozzle forming surfaces of the recording heads 7, 8, 9 during non-printing. A function of preventing drying of the ink, and a suction pump 13 serving as a negative pressure generating means during a cleaning operation.
It also has a function of forcibly discharging ink from the nozzle openings of the recording heads 7, 8, and 9 by receiving a negative pressure from the recording head.

In the vicinity of the printing area side of the capping device 20, dust or ink such as paper dust or the like adhering to the nozzle forming surface by resiliently contacting the nozzle forming surface of the recording heads 7, 8, 9 as necessary. The wiping member 14 made of an elastic material such as rubber for wiping and removing the recording heads 7 and 8
9 are arranged so as to be able to advance and retreat on the nine movement trajectories.

FIGS. 2 to 8 show a part of the carriage 1 and the structure of the capping device 20. FIG. 2 is a perspective view, FIG. 3 is a bottom view of the carriage 1, and FIG. 4 is a plan view of the capping device 20. FIG. 5 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a side view of a part of the carriage 1 and the capping device 20 as viewed in the main scanning direction. FIG. 7 is a cross-sectional view taken along line BB in FIG. 4 in the direction of the arrow, and FIG. 8 is a cross-sectional view taken along line CC of FIG. 4 in the direction of the arrow.

First, as shown in FIGS. 2 and 3, recording heads 7, 8, and 9 are arranged in the main scanning direction in parallel on the bottom surface of the carriage 1, and as shown in FIG. Nozzle forming surfaces 7a, 8a,
Although not shown in the figure, a large number of fine nozzle openings 9a are formed in a row in 9a to form a multi-nozzle recording head.

At both ends of the carriage 1 in the moving direction, a positioning guide 15 cut out in a U-shape is provided.
Are formed respectively. The positioning guide 15
Are a reference surface 15a which is a reference of the alignment position in the main scanning direction which is a moving direction of the carriage 1, and the reference surface 15a
A reference surface 15b, which serves as a reference for the alignment position in the sub-scanning direction, which is the recording paper conveyance direction orthogonal to a, is formed.

On the other hand, when the capping device 20 advances toward the carriage 1, a cap member 21 made of a flexible material such as rubber for sealing the nozzle forming surfaces 7a, 8a, 9a of the recording head is provided. 22 and 23 and cap holder 2 for accommodating each cap member 21, 22 and 23
4, a cap frame 25 disposed below the cap holder 24 and holding the cap holder 24, and an elastic body between the cap frame 25 and the cap members 21, 22, 23 as shown in FIGS. And the cap frame 25 is driven by driving means 29 described later.
The recording heads 7, 8, and 9 are configured to be able to advance and retreat within a predetermined range.

The cap holder 24 is a plate having a substantially rectangular shape, and has rectangular receiving holes 30, 3 for receiving the cap members 21, 22, 23 as shown in FIG.
A pair of rectangular through holes 3 are provided between the receiving holes 30 and 31 and between the receiving holes 31 and 32.
3 are provided.

In the vicinity of both ends on the upper surface of the cap holder 24, guide projections 34 facing the positioning guides 15 arranged on the carriage 1 are provided upright. As shown in FIG. 4, when the carriage 1 advances toward the carriage 1 as shown in FIG.
An inclined surface 34a having an inclination angle of about 70 degrees and slidingly contacting the reference surface 15a formed on the side of the carriage 1;
An inclined surface 34b having an inclination angle of about 70 degrees which is in sliding contact with the reference surface 15b formed on the side is formed. Then, as shown in FIG.
A plurality of columnar projections 3
5 is provided, and a tapered hole 36 for centering the cap member is provided on the tip end surface of the projection 35.

On the other hand, since the cap members 21, 22, and 23 have the same shape, the cap member 21 will be described as a representative. The cap member 21 is formed of a flexible rubber material as described above. As shown in FIG. 5 and FIG. 7, an annular projection 21b projecting upward is integrally formed on a peripheral portion of a base member 21a formed in a substantially rectangular shape.

When the annular projection 21b comes into contact with the nozzle forming surface of the recording head 7, it comes into close contact with the periphery of the nozzle opening.
FIG. 7 is for forming a space for sealing the nozzle opening.
As shown in (1), the base member 21a has an opening in a conduit 37 communicating with the suction pump 13, which is a negative pressure generating means.

An annular wall 21c protruding downward is provided at the peripheral edge of the base member 21a, and a stopper wall 21d extending horizontally from the lower end of the annular wall 21c is provided. A taper pin 38 that fits into the cap member centering taper hole 36 is provided upright on the upper surface of the stopper wall 21d. When the cap member 21 is urged upward by the cap spring 26, the taper pin 38 The cap holder 24 is pressed upward through the centering taper hole 36.

In the embodiment shown in the figures, the cap holder 24 has a taper hole 36 for centering the cap member.
And the cap member 21 is provided with a taper pin 38. However, the taper pin 38 may be provided on the cap holder 24 and the cap member 21 may be provided with a taper hole 36 for centering the cap member.

The cap frame 25 has a box shape with an open top, and as shown in FIG.
5 are provided with upright columns 39 protruding from the inner bottom surface toward the respective through holes 33 formed in the cap holder 24.

The upright pillars 39 loosely fit into the through holes 33 formed in the cap holder 24, respectively, and
4, a gap S formed between the through hole 33 of FIG.
Is configured to have a size larger than the amount by which the cap holder 24 is aligned in the lateral direction.

An engaging protrusion 40 extending in the lateral direction is formed at a tip end of the upright column 39 penetrating the through hole 33, and an upper stopper surface 40a is formed on a lower surface of the engaging protrusion 40. Further, the upper end of the side wall 41 of the cap frame 25 forms a lower stopper surface 41a.
Therefore, the cap holder 24 has the two stopper surfaces 40.
It is configured to be able to move up and down (in the direction of the recording head) in the range of a and 41a.

Driving means 29 for moving the cap frame 25 toward and away from the recording head includes, as shown in FIG.
A bracket 42 formed on the outer bottom surface of the cap frame 25 is pivotally supported at one end, and a drive arm 43 whose base end is pivotally attached to a frame 44 of the recording apparatus;
A float spring 45 disposed between the bottom of the frame 2 and the frame 44; and a cam disposed at an intermediate position between the drive arm 43 and pushing the drive arm 43 in a direction opposite to the biasing direction of the float spring 45. Cam member 46 with surface 46a
It is composed of The pressing force of the float spring 45 pressing the cap frame 25 toward the recording head is larger than the sum of the pressing forces of the cap springs 26, 27, 28.

Next, the operation of the capping device 20 will be described with reference to FIGS. FIG. 5 shows the positional relationship of the capping device 20 facing the carriage 1 during the flushing operation. During the flushing operation, the carriage 1 returns to the home position facing the capping device 20, and the recording heads 7, 8,
A drive signal irrelevant to printing is applied to 9, and idle ink is ejected toward the cap members 21, 22, and 23.

At the time of this flushing operation, as shown in FIG. 5, since the capping device 20 has retreated to the lower standby position, there is a gap between the guide projection 34 and the nozzle plates 7a, 8a, 9a. Some gaps are formed,
It is configured so as not to hinder the movement of the carriage 1.

Next, a description will be given of a capping operation in which the nozzle opening is sealed when printing is stopped, or the nozzle forming surface is sealed to suck and discharge ink from the nozzle opening by the negative pressure from the suction pump 13. .

When the apparatus is stopped or when a cleaning command is received, the carriage 1 moves to the same position as in the flushing operation shown in FIG.
Confront 0. At this time, cap springs 26, 27, 28
Presses the cap holder 24 via the cap members 21, 22, 23, so that the cap holder 24 is advanced upward until it comes into contact with the upper stopper 40 a of the cap frame 25.

As shown in FIG. 7, since the taper pins 38 are fitted in the centering taper holes 36, the cap members 21, 22, and 23 are inserted into the accommodation holes 30, 31, and 32 of the cap holder 24. Positioned accurately without eccentricity.

However, as shown in FIGS. 5 and 6, the return position of the carriage 1 or the capping device 2
0, the recording heads 7, 8,
9 and the center positions of the cap members 21, 22, and 23 do not always match.

In this state, when the drive arm 43 is tilted upward by the rotation of the cam member 46 shown in FIG. 9, the capping device 20 pressed by the float spring 44 advances toward the recording head. Thereby, the cap holder 2
4 is inserted into the positioning guide 15 of the cap member 1. Therefore, each of the inclined surfaces 34 a and 34 b formed on the guide protrusion 34 advances toward the carriage while abutting on the positioning guide 15.
The gap d1 with the cap frame 25 shown in FIG.
As shown in FIG. 2, the gap is reduced to d2.

As described above, since the gap d1 between the cap holder 24 and the cap frame 25 is reduced to the gap d2, as shown in FIG.
A gap g (gap g = gap d1−gap d2) is generated between the engagement projection 40 formed on the upper surface of the cap holder 24 and the cap holder 24.
5 can be freely moved in the lateral direction without receiving the frictional resistance.

Therefore, as shown in FIG. 14 and FIG. 15, the cap holder 24 holds the cap member 2 in the process of inserting the guide projection 34 into the positioning guide 15.
Centering is performed so that the center positions of the recording heads 1, 22, 23 coincide with the center positions of the recording heads 7, 8, 9, respectively.

Further, since the capping device 20 moves forward, the centered cap member 2 as shown in FIG.
The nozzles 1, 22, and 23 contact the nozzle forming surfaces of the recording heads 7, 8, and 9 to seal the nozzle openings. Then, when the cap holder 24 substantially contacts the carriage 1, the rotation of the cam member 46 is stopped. As a result, the advance of the capping device 20 is stopped as shown in FIGS. The capping operation is completed.

Therefore, when the recording apparatus is at rest, all of the nozzle openings formed in each of the recording heads 7, 8, and 9 are in a sealed state, so that the ink solvent is prevented from evaporating from the nozzle openings. . Further, during the cleaning operation, the suction pump 13 is driven, and the sealing spaces of the cap members 21, 22, and 23 are suctioned to a negative pressure. The viscous ink can be sucked and discharged.

In the embodiment described above, an example is shown in which the carriage is loaded with three recording heads and the cap holder is provided with three corresponding cap members. It goes without saying that the number of heads and cap members can be one or two, and even four or more.

[0052]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the capping apparatus used for the apparatus can be constructed relatively simply, and the guide provided on the cap holder is provided. When the projection comes into contact with the carriage, the centering operation is performed smoothly and reliably. For this reason, the cap member accommodated in the cap holder can reliably seal all the nozzle openings formed in the recording head. This makes it possible to effectively prevent the evaporation of the ink solvent from each nozzle opening in the capping state while the printing apparatus is at rest, and to increase the viscosity of all the nozzle openings of the printing head in the cleaning operation. The ink can be sucked and discharged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus according to the present invention.

FIG. 2 is a perspective view showing a capping device and a carriage mounted on the recording device shown in FIG.

FIG. 3 is a bottom view of the carriage shown in FIG. 2;

FIG. 4 is a plan view of the capping device shown in FIG.

FIG. 5 is a cross-sectional view taken along line AA in FIG. 4 in the direction of the arrow.

FIG. 6 is a side view of a part of the carriage and a capping device as viewed in a main scanning direction.

FIG. 7 is a cross-sectional view taken along line BB in FIG. 4 in the direction of the arrow.

FIG. 8 is a cross-sectional view taken along line CC in FIG. 4 in the direction of the arrow.

FIG. 9 is a side view of driving means for moving the cap holder forward and backward.

FIG. 10 is a longitudinal sectional view of the carriage and the capping device, showing a state in which the alignment of the cap holder is started.

11 is a side view of the carriage and the capping device in the state shown in FIG.

FIG. 12 is a longitudinal sectional view of a carriage and a capping device showing a sliding contact state of a guide projection.

FIG. 13 is a longitudinal sectional view illustrating a state in which the cap holder can move in the horizontal direction.

FIG. 14 is a longitudinal sectional view of the carriage and the capping device showing a state where the cap member is aligned.

FIG. 15 is a side view of the carriage and the capping device in the state shown in FIG. 14;

FIG. 16 is a longitudinal sectional view showing a state in which the cap member seals the recording head.

FIG. 17 is a longitudinal sectional view showing a state where the capping device is further advanced.

18 is a longitudinal sectional view of the state shown in FIG. 17 as viewed from a direction perpendicular to the state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 7, 8, 9 Recording head 7a, 8a, 9a Nozzle plate 15 Positioning guide 15a, 15b Reference surface 20 Capping device 21, 22, 23 Cap member 24 Cap holder 25 Cap frame 26, 27, 28 Cap spring 29 Drive Means 30, 31, 32 Housing hole 33 Through hole 34 Guide projection 36 Cap member centering tapered hole 37 Pipe line 38 Tapered pin 40a Upper stopper surface 41a Lower stopper surface 43 Drive arm 45 Float spring

Claims (7)

[Claims] An ink jet type in which a recording head having a nozzle opening is mounted on a carriage moving in the width direction of a recording sheet, and ink droplets are ejected from the nozzle opening during the movement of the carriage to form an image on the recording sheet. A recording apparatus, wherein the cap frame is disposed at a home position outside a printing area by the recording head, and is arranged so as to be able to advance and retreat toward the recording head in a state where the carriage returns to the home position; and Driving means for driving the cap frame in the reciprocating direction, the driving means being engaged with the cap frame so that the cap frame can reciprocate by a predetermined amount, and being movably provided in a direction perpendicular to the reciprocating direction, and the carriage when being advanced. In contact with a part of
A cap holder having a guide projection whose center in the orthogonal direction is centered, a cap member housed in the cap holder and sealing the nozzle opening when the cap frame advances, and An ink jet recording apparatus comprising an urging member for pushing a cap holder in a forward direction. 2. A plurality of through-holes are provided in the cap holder, and the amount of advance and retreat of the cap holder is limited to upright columns which are erected on the cap frame and loosely fit into the plurality of through-holes, respectively. 2. The ink jet recording apparatus according to claim 1, further comprising a stopper surface. 3. An inclined surface for slidingly contacting the positioning guide and aligning the cap holder when the guide projection is inserted into a positioning guide provided on the carriage. The ink jet recording apparatus according to claim 1 or 2, wherein 4. The ink jet recording apparatus according to claim 3, wherein a gap larger than the alignment amount of the cap holder is formed between the through hole and the upright column. 5. A cap member centering member to which the taper pin fits when one of the cap member and the cap holder has a tapered pin erected on the other and the cap member contacts the cap holder. 5. The ink jet recording apparatus according to claim 1, wherein said tapered hole is provided. 6. The ink jet recording apparatus according to claim 1, wherein the urging member is a cap spring inserted between the cap frame and the cap member. 7. A float spring for biasing the cap frame in a forward direction, and a cam member having a cam surface for pushing the cap frame in a direction opposite to the bias direction by the float spring. 7. The ink jet recording apparatus according to claim 1, wherein the urging force of the float spring is larger than the urging force of the cap spring. 8.