JP2001199079A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control driving of an air pressurizing pump correctly in a recorder where ink is supplied from a main tank to the side of a recording head carried on a carriage by an air pressure generated from the air pressurizing pump. SOLUTION: A pressure detector 23 for detecting the pressure of pressurized air is disposed in an air channel between an air pressurizing pump and a main tank. Driving of the air pressurizing pump is controlled based on a control signal generated by detecting the air pressure through the pressure detector. The pressure detector 23 comprises a diaphragm 43 displaced by the pressure of the pressurized air, and an output generating means 46 comprising a photosensor generating a control signal based on the displacement of the diaphragm wherein the pressurizing pump is driven intermittently by the control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurized air generated by an air pressurizing pump applied to a main tank in which ink is stored, and is mounted on a carriage from the main tank by the action of the pressurized air. And an ink jet recording apparatus configured to supply ink to the recording head side.

[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 generally mounted on a carriage and moves in the width direction of a recording sheet, and an ink jet recording head;
Paper feed means is provided for relatively moving the recording paper in a direction perpendicular to the direction of movement of the recording head. Recording is performed on the recording paper by discharging ink droplets from the recording head based on print data. Will be

A recording head capable of ejecting, for example, black, yellow, cyan, and magenta inks is mounted on a carriage, and not only text printing using black ink but also changing the ejection ratio of each ink is performed.
Enables full-color printing.

On the other hand, in this type of recording apparatus provided for office use or business use, it is necessary to provide a large-capacity ink cartridge in order to cope with a relatively large amount of printing. 2. Description of the Related Art A recording device of a type in which a main tank as a cartridge is loaded into a mounting device (cartridge holder) disposed on, for example, the apparatus main body side is provided.

A sub-tank is arranged on a carriage on which the recording head is mounted. Ink is supplied from each of the main tanks to each of the sub-tanks via an ink supply tube. It is configured to supply ink thereto.

[0006]

In recent years, there has been a demand for a large-sized recording apparatus capable of performing printing on a large sheet of paper and having a long scanning distance of a carriage. In such a printing apparatus, in order to improve the throughput, the number of nozzles in the printing head is increased more and more. Furthermore, in order to improve throughput, it is possible to replenish ink from the main tank to each sub-tank mounted on the carriage sequentially while performing printing, and to stabilize the ink from each sub-tank to the print head. There is a demand for a recording device that supplies the data.

In such a recording apparatus, it is necessary to connect an ink supply tube corresponding to each ink from the main tank to the sub-tank on the carriage. And the routing distance increases. Moreover, as described above, since the number of nozzles in the recording head is increased, the ink consumption is large, the dynamic pressure of the ink increases in each ink supply tube connected from the main tank to the sub tank, and the There is a technical problem that the ink supply amount is insufficient.

As one means for solving such a problem, for example, air pressure is applied to the main tank side, a forced ink flow is generated from the main tank to the sub tank by air pressure, and A configuration in which necessary and sufficient ink is supplied can be employed.

In order to adopt such a configuration, an air pressurizing pump for applying pressurized air to the main tank is required. This air pressurizing pump is constantly driven while the driving power supply to the recording apparatus is turned on, so that the pressurized air can be stably applied to the main tank side. Operation can be guaranteed.

However, when the pressure pump is constantly driven, noise generated by the pressure pump becomes a problem, and durability of the pressure pump also becomes a problem. Therefore, there is another problem that the cost for these measures is increased. Therefore, it is desired that the pressurizing pump be driven intermittently within a range where an appropriate air pressure for each main tank can be maintained.

The present invention has been made based on the technical problem described above, and detects air pressure applied to a main tank from a pressurized pump, and uses a control signal based on the detected value to control the pressurized pump. It is an object of the present invention to provide an ink jet recording apparatus configured to control the driving of the ink jet recording apparatus so that the air pressure applied to the main tank can always be controlled within an appropriate range.

[0012]

In order to achieve the above object, an ink jet recording apparatus according to the present invention comprises a pressurized air generated by an air pressurizing pump for a main tank in which ink is stored. Is applied, and ink is supplied from the main tank to the recording head mounted on the carriage by the action of the pressurized air, wherein an ink is supplied between the air pressurizing pump and the main tank. In the air flow path, a pressure detector that detects the pressure of the pressurized air is arranged, and based on a control signal generated by a pressure detected by the pressure detector,
It is configured to control the driving of the air pressurizing pump,
The pressure detector includes a diaphragm that is displaced by receiving the air pressure of pressurized air, and an output generating unit that generates a control signal based on the amount of displacement of the diaphragm.

[0013] In this case, preferably, the outer periphery of the main tank is formed in an airtight state, an ink pack formed of a flexible material in which ink is sealed is housed inside, and an outer constituting member of the main tank is provided. The pressurized air generated by the air pressurizing pump is applied to a pressure chamber formed by the ink and the ink pack.

Preferably, ink is supplied from the main tank to a sub-tank mounted on a carriage via an ink supply path, and the ink is supplied from the sub-tank to the recording head mounted on the carriage. Be composed. In addition, it is desirable that the ink supply path from the main tank to the sub tank is constituted by a flexible ink supply tube.

[0015] In a preferred embodiment,
The output generating means includes a movable member that is moved forward and backward by the displacement of the diaphragm, and a photosensor including a light source and a light receiving element arranged so as to cross the moving path of the movable member, and constitutes the photosensor. The control signal is generated based on the output of the light receiving element.

In another preferred embodiment, the output generating means includes a movable member that is moved forward and backward by a displacement of a diaphragm, a light source that projects light on a movement path of the movable member, and a movement of the movable member. And a light sensor that receives the reflected light of the light source based on the light sensor, and is configured to generate the control signal based on an output of the light sensor that constitutes the photo sensor.

In any of the above embodiments, the diaphragm is made of an elastic material, and the movable member is moved forward and backward based on the displacement of the diaphragm due to the balance between the air pressure received by the diaphragm and the return force of the diaphragm. A configuration adapted to do so may be employed. The diaphragm further includes a spring member that urges the diaphragm in a return direction, and the movable member is configured to move based on a displacement of the diaphragm due to a balance between an air pressure received by the diaphragm, a return force of the diaphragm, and an urging force of the spring member. Can be adopted.

On the other hand, the diaphragm is preferably made of rubber. The diaphragm may be made of rubber and cloth. In this case, it is preferable that the movable member is formed with a step portion for preventing excessive displacement of the diaphragm due to air pressure. further,
It is preferable that a stopper member for preventing excessive displacement of the diaphragm by receiving the urging force of the spring member is provided.

Further, the movable member may adopt a configuration molded integrally with the diaphragm. In any of the above embodiments, the diaphragm is arranged so as to close the opening of the case, so that a space is formed inside the case to receive air pressure from the air pressurizing pump. A connecting pipe for introducing pressurized air from an air pressurizing pump into the space in the case, and a plurality of pipes for distributing pressurized air from the space to each main tank. And a connecting pipe for distributing the pressurized air.

According to the above-described ink jet recording apparatus, pressurized air generated by the pressurizing pump is applied to the main tank, and the pressurized air is applied to the recording head mounted on the carriage by the action of the air pressure. A necessary and sufficient amount of ink can be supplied. The pressurized state of the main tank is monitored by a pressure detector arranged in an air flow path between the air pressurizing pump and the main tank, and a control signal generated by the pressure detector controls the pressurized pump. Is controlled to be driven intermittently.

In this case, the pressure detector is provided with a diaphragm that is displaced by receiving the air pressure of the pressurized air, and the output generating means controls the driving of the pressurizing pump based on the amount of displacement of the diaphragm. Generate a signal. The output generating means includes a movable member which is moved forward and backward by the displacement of the diaphragm, and a control signal for controlling the driving of the pressurizing pump is generated by detecting a moving state of the movable member by a photo sensor. .

Accordingly, since the pressure detector is constituted by a relatively simple structure including the diaphragm and the photosensor, it can be realized at relatively low cost. In addition, the control signal generated by the pressure detector acts so that the pressurizing pump is driven intermittently, which eliminates noise and durability problems due to the constant driving of the pressurizing pump. It is possible to do.

[0023]

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 is a top view showing an example of an ink jet recording apparatus to which the present invention can be applied. In FIG. 1, reference numeral 1 denotes a carriage. The carriage 1 is guided by a scanning guide member 4 via a timing belt 3 driven by a carriage motor 2 in a longitudinal direction of a paper feeding member 5, that is, in a width direction of the recording paper. It is configured to reciprocate in a certain main scanning direction. Then, although not shown in FIG.
An ink jet recording head 6 described later is mounted on a surface facing the paper feed member 5.

The carriage 1 has sub-tanks 7a to 7d for supplying ink to the recording head. In this embodiment, four sub-tanks 7a to 7d are provided corresponding to the respective inks in order to temporarily store the respective inks therein. Then, main tanks 9a to 9 serving as ink cartridges loaded in cartridge holders 8 arranged at the ends of the apparatus with respect to the sub tanks 7a to 7d.
, d through the flexible ink supply tubes 10, 10,... constituting the ink supply path, respectively.
It is configured so that yellow, magenta, and cyan inks are supplied.

On the other hand, in a non-printing area (home position) on the moving path of the carriage 1, a capping means 11 capable of sealing the nozzle forming surface of the recording head is arranged.
A cap member 11a made of a flexible material such as rubber capable of sealing the nozzle forming surface of the recording head is disposed on the upper surface of the recording head 1. When the carriage 1 moves to the home position, the cap member 11a
Thus, the nozzle forming surface of the recording head is sealed.

The cap member 11a seals the nozzle forming surface of the recording head during the pause of the recording apparatus,
It functions as a lid that prevents drying of the nozzle openings. Although not shown in the drawing, one end of a tube of a suction pump (tube pump) is connected to the cap member 11a, and a negative pressure generated by the suction pump is applied to the recording head so that ink is discharged from the recording head. The cleaning operation for sucking and discharging is performed.
Further, a wiping member 12 made of an elastic material such as rubber is arranged on the printing area side adjacent to the capping means 11 so that the nozzle forming surface of the recording head can be wiped and cleaned as necessary. It is configured.

Next, FIG. 2 schematically shows the configuration of an ink supply system mounted on the recording apparatus shown in FIG. 1. This ink supply system will be described with reference to FIG. . 1 and 2, reference numeral 21 denotes an air pressurizing pump. The air pressurized by the air pressurizing pump 21 is supplied to a pressure regulating valve 22, and the pressure detecting valve 22 supplies a pressure detector. Pressurized air is supplied to each of the main tanks 9a to 9d (represented by reference numeral 9 in FIG. 2 and may be simply represented by reference numeral 9 in the following) via the reference numeral 23. It is configured to be.

The pressure regulating valve 22 is provided with the air pressurizing pump 2
When the air pressure pressurized by 1 reaches an excessive state, the air pressure is released to maintain the air pressure applied to each of the main tanks 9a to 9d within a predetermined range. This is because some trouble occurs in the control system by the pressure detector 23 and the air pressurizing pump 21 which will be described later, and the pressurizing pump 2
1 continues the driving state, and excessive air pressure
And acts to avoid problems such as damage to the ink pack 24 described later.

Further, the pressure detector 23 functions to detect the air pressure pressurized by the air pressurizing pump 21 and control the driving of the air pressurizing pump 21. That is,
When it is detected that the air pressure pressurized by the air pressurizing pump 21 has reached a predetermined pressure, the driving of the air pressurizing pump 21 is stopped, and the air pressure is lower than the pressure determined by the pressure detector 23. When the main tank 9a is detected, it is controlled to drive the air pressurizing pump 21.
It functions so that the air pressure applied to ９9d is maintained in a predetermined range.

As shown in FIG. 2, the outline of the main tank 9 is formed in an airtight state, and the inside of the main tank 9 is formed of a flexible material filled with ink. The pack 24 is stored. The space formed by the main tank 9 and the ink pack 24 constitutes a pressure chamber 25, and pressurized air is supplied into the pressure chamber 25 via the pressure detector 23. ing. With this configuration, each main tank 9
The ink packs 24 stored in the main tanks 9a to 9d receive the pressure of the pressurized air, respectively.
Thus, an ink flow is generated for each of the sub-tanks 7a to 7d.

The ink pressurized in the main tanks 9a to 9d is supplied to the ink supply valves 26, 26,... And the ink supply tubes 10, 10,. Each of the sub-tanks 7a to 7d mounted on the carriage 1
(In FIG. 2, it is represented by reference numeral 7 and may be simply represented by reference numeral 7 in the following description.)

As shown in FIG. 2, the sub-tank 7 has a float member 31 disposed therein, and a permanent magnet 32 is attached to a part of the float member 31. . The magneto-electric conversion elements 33 a and 33 b typified by Hall elements are mounted on the substrate 34 and are attached to the side wall of the sub tank 7. With this configuration, the permanent magnet 32 disposed on the float member 31
And the Hall element 33a, according to the magnetic flux by the permanent magnet 32 according to the floating position of the float member.
33b constitutes an ink amount detecting means for generating an electric output.

Therefore, for example, when the amount of ink in the sub-tank 7 decreases, the position of the float member 31 housed in the sub-tank moves in the direction of gravity, and accordingly, the position of the permanent magnet 32 also changes in the direction of gravity. Go to Therefore, the Hall elements 33a, 33b due to the movement of the permanent magnet
Can be sensed as the amount of ink in the sub tank 7, and the ink supply valve 26 is opened by the electric output obtained by the Hall elements 33a and 33b. As a result, the ink pressurized in the main tank 9 is individually sent into each of the sub-tanks 7 in which the ink amount has decreased.

When the amount of ink in the sub tank 7 reaches a predetermined capacity, the ink supply valve 26 is closed based on the electric output of the hall elements 33a and 33b. By such repetition, the ink acts to intermittently replenish the ink from the main tank to the sub-tank, so that substantially constant ink is always stored in each sub-tank.

As described above, each ink pressurized by air pressure in the sub-tank is supplied to each sub-tank based on an electric output based on the position of each float member arranged in the sub-tank. As a result, the ink supply response can be improved, and the amount of ink stored in the sub-tank can be appropriately managed.

A valve 35 is provided from each sub-tank 7.
And ink is supplied to the recording head 6 via a tube 36 connected to the recording head 6. Based on print data supplied to an actuator (not shown) of the recording head 6, the recording head 6 The ink droplets are ejected from the nozzle openings 6a formed on the nozzle forming surface of the nozzle. In FIG. 2, reference numeral 11 denotes the above-described capping means, and a tube connected to the capping means 11 is connected to a suction pump (tube pump) not shown.

FIG. 3 is a sectional view showing a first embodiment of the pressure detector 23 described above. The pressure detector 23 includes an upper case 41 having a cylindrical outer shape and a lower case 4 having a cylindrical outer shape.
The upper case 41 and the lower case 4
2, a diaphragm 43 formed in a disk shape by a flexible elastic member is disposed in a form in which a peripheral edge portion thereof is sandwiched. As shown in FIG. 3, the diaphragm 43 has a thick portion 43a formed at the center thereof.
A thin portion 43b having a semicircular cross section is formed between the thick portion 43a and the peripheral portion. The diaphragm 43 is preferably made of a rubber material. Further, the diaphragm 43 may be formed in a state in which the cloth is filled with a rubber material, and in this case, the durability as the diaphragm can be enhanced.

On the other hand, the cylindrical body 4
1a is formed integrally, and an inner cylinder 41b is formed at an upper part further inside the cylinder 41a so as to be integral with the cylinder 41a. In the sectional state shown in FIG. 3, the inner cylinder 41b is drawn in a floating state, but the inner cylinder 41b is orthogonal to the state shown in the figure in the circumferential direction. It is connected to the cylindrical body 41a at the position. In other words, as shown in FIG.
A pair of openings 41c are formed between and the inner cylinder 41b so as to face each other.

The movable member 4 is provided inside the cylindrical body 41a.
4 are housed so as to be slidable in the axial direction (vertical direction in FIG. 3). The movable member 44 is formed in a bifurcated shape, and a claw-shaped stopper member 44a is formed at each end portion. The stopper member 44a enters the opening portion 41c to form an upper end portion of the cylindrical body 41a. It is configured to engage with.

The movable member 44 is provided with an upright portion 44b which is integrally erected from the inner bottom thereof. In the embodiment shown in FIG. 3, the lower end of the inner cylinder 41b is connected to the movable member 44b. An upright portion 44b
Is wound, and a coil-shaped spring member 45 is provided. With this configuration, the movable member 44 is configured to be urged downward in the figure by a spring member 45, whereby the lower bottom portion of the movable member 44 is positioned at the center thick portion 43 a of the diaphragm 43. It is configured to contact the upper surface.

On the other hand, the lower case 42 is supplied with pressurized air from the air pressurizing pump 21 at the lower bottom thereof.
A connection pipe 42b for introducing pressurized air for introducing into a space 42a between the space 43a and the diaphragm 43;
A plurality of pressurized air distribution connection pipes 42c for distributing pressurized air to each of the main tanks 9 from a. In this embodiment, four main tanks 9 are provided as described above, and in this case, four connection pipes 42c for distributing the pressurized air are provided according to the number thereof. FIG. 4 shows this in a cross-sectional view, and shows two connection pipes 42c for distributing pressurized air.

With this configuration, the pressurized air from the air pressurizing pump 21 is introduced into the space 42a of the pressure detector 23 via the connection pipe 42b for introducing the pressurized air, and the pressurized air is distributed to each pressurized air. Of each main tank 9 via the connecting pipe 42c of
, And pressurized air is applied to the pressure chamber 25 at. Then, under the action of the pressurized air introduced into the space 42a, the diaphragm 43 is displaced upward in the drawing, and acts so as to push the movable member 44 upward. A space formed between the diaphragm 43 and the upper case 41 is communicated with the atmosphere via a gap between the cylindrical body 41a and the movable member 44.

In this embodiment, as described above, the movable member 44 is configured to be urged downward in the figure by the spring member 45, so that the air pressure received by the diaphragm 43 and The movable member 44 is moved up and down based on the displacement of the diaphragm due to the balance between the elasticity of the diaphragm and the biasing force of the spring member 45.

On the other hand, a photo sensor 46 which constitutes an output generating means is disposed on a moving path of a leading end of the upright portion 44b formed on the movable member 44. In the photo sensor 46, a light source 46a and a light receiving element 46b are arranged so as to face each other.
When the diaphragm 43 is displaced by a predetermined amount or more in response to the pressurized air introduced into the movable member 2a, the tip of the upright portion 44b formed on the movable member 44 is connected to the light source 46a and the light receiving element constituting the photo sensor 46. It acts to block the optical axis with 46b.

Therefore, when the air pressurizing pump 21 is driven and the pressurized air reaches a predetermined pressure or more, the upright portion 44b is pushed up by the displacement of the diaphragm, and the optical axis by the photo sensor 46 is cut off. The driving of the air pressurizing pump 21 is stopped based on the output of the light receiving element 46b at this time. When the air pressure is reduced due to ink consumption or the like, the leading end of the upright portion 44b formed on the movable member 44 is moved by the light source 46a by the return force due to the elasticity of the diaphragm and the urging force of the spring member 45. And the light receiving element 46b are separated from the optical axis. As a result, an output is generated at the light receiving element 46b, and a control signal for driving the air pressurizing pump 21 is generated based on the output.

In this case, the control signal based on the output of the light receiving element 46b constituting the photo sensor may be used, for example, to drive or stop a motor (not shown) directly connected to the air pressurizing pump 21. Alternatively, in the case where a motor for driving another mechanism unit is also used, it can be used to control the engagement of a clutch mechanism (not shown) arranged in the drive system.

As shown in part A of FIG. 3, the movable member 44 has a step portion 44d for preventing the diaphragm 43 from excessively preventing displacement when pressurized air is received. Have been. In order to explain this configuration and operation, part A of FIG. 3 is enlarged in FIG. That is, the diagram shown in the upper half of FIG. 4 shows a state in which the diaphragm receives a normal or lower air pressure, and the diagram shown in the lower half of FIG. This shows a received state.

As shown in FIG. 4, when the diaphragm changes from a state in which the diaphragm receives a normal or lower air pressure to a state in which the diaphragm receives a predetermined or higher air pressure, the movable member 44 moves upward in the figure. The stepped portion 4 formed on the upright portion 44b that moves and is integrally raised from the inner bottom portion of the movable member 44
4d is a contact portion 41d that constitutes a lower end portion of the inner cylindrical body 41b.
To prevent the movable member 44 from further rising. Thereby, the diaphragm 43
Is prevented from undergoing an excessive displacement, and a normal function as the pressure detector 23 is guaranteed.

In the embodiment shown in FIG. 3, the movable member 44 is formed in a bifurcated shape, and a claw-shaped stopper member 44a is disposed at each of the distal ends. By engaging with the upper end of the cylindrical body 41a, the diaphragm 43 is prevented from receiving an excessive displacement by the spring member 45. However, in the case where the above-mentioned claw-shaped stopper member 44a is not formed, the lower case 4
It is desirable that a cylindrical stopper member 42d is integrally formed at the center of the lower bottom portion 2 as shown by an imaginary line, thereby acting to prevent excessive displacement of the diaphragm.

Next, FIG. 5 is a sectional view showing a second embodiment of the pressure detector. The configuration of the pressure detector 23 shown in FIG. 5 is the same as that of the embodiment shown in FIGS. 3 and 4 except for the photosensor 46. Therefore, portions corresponding to the representative portions shown in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the embodiment shown in FIG. 5, the photosensor 46 receives the reflected light of the light source 46a for projecting light and the light source based on the movement of the upright portion 44b along the movement path of the upright portion 44b of the movable member. It is composed of a light receiving element 46b. Therefore, in this configuration,
Either a white synthetic resin material having good reflection characteristics is used as the upright portion 44b, or a reflecting member 44c made of, for example, aluminum foil or the like is disposed at the upright portion 44b corresponding to the path of the projection light in the light source 46a. It is desirable.

According to the configuration shown in FIG. 5, when the air pressurizing pump 21 is driven and the pressurized air reaches a predetermined pressure or more, the upright portion 44b of the movable member is pushed up by the displacement of the diaphragm 43, and the upright portion is raised. The tip of the portion 44b or the reflecting member 44c disposed thereon is
It receives the projection light from 6a and reflects it to the light receiving element 46b side. Based on the output of the light receiving element 46b, a control signal for stopping the driving of the air pressurizing pump 21 is generated.

When the air pressure decreases due to the consumption of ink or the like, the leading end of the upright portion 44b formed on the movable member 44 is moved by the return force due to the elasticity of the diaphragm and the urging force of the spring member 45. Away from the optical axis of the light source 46a. Thus, the projection of the reflected light to the light receiving element 46b is cut off, and a control signal for driving the air pressurizing pump 21 is generated.

In the above-described embodiment of the pressure detector 23 shown in FIGS. 3 to 5, the lower end of the inner cylinder 41b formed in the upper case 41 and the movable member 44 are all provided.
A coil-shaped spring member 45 is disposed so as to wind the upright portion 44b between the spring member 45 and the inner bottom portion. However, the pressure detector 23 having the same function can be configured even in a configuration excluding the spring member 45.

In this case, the movable member moves forward and backward based on the displacement of the diaphragm due to the balance between the return force of the diaphragm 43 made of an elastic material and the air pressure received by the diaphragm. Therefore, when adopting such a configuration,
The lower bottom of the movable member 44 is the thick portion 43 of the diaphragm 43.
a, or the thick part 43a of the diaphragm 43 is formed integrally with the lower bottom of the movable member 44, and the two parts are mechanically connected to each other. .

[0056]

As apparent from the above description, according to the ink jet recording apparatus of the present invention, the pressure of the pressurized air is detected in the air flow path between the air pressurizing pump and the main tank. A pressure detector is provided, and driving of the pressurizing pump is controlled based on a control signal generated by a pressure detected by the pressure detector. Therefore,
Noise generated by the constant operation of the pressurizing pump,
It is also possible to solve the problem about durability.

In addition, the pressure detector is configured to include a diaphragm that is displaced by receiving the air pressure of pressurized air and an output generating means that generates a control signal based on the amount of displacement of the diaphragm. The driving of the pressurizing pump can be controlled by a simple structure, which contributes to improving the reliability of the operation of this type of ink jet recording apparatus.

[Brief description of the drawings]

FIG. 1 is a plan view showing an overall configuration of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic diagram illustrating an ink supply system from a main tank to a recording head.

FIG. 3 is a sectional view showing a first embodiment of a pressure detector used in the ink supply system shown in FIG. 2;

FIG. 4 is an enlarged cross-sectional view showing a configuration of a part of the pressure detector shown in FIG. 3;

FIG. 5 is a cross-sectional view showing a pressure detector according to a second embodiment.

[Explanation of symbols]

Reference Signs List 1 carriage 6 recording head 7 (7a, 7b, 7c, 7d) sub tank 8 cartridge holder 9 (9a, 9b, 9c, 9d) main tank (ink cartridge) 10 ink supply tube (ink supply path) 21 air pressure pump 22 Pressure adjusting valve 23 Pressure detector 24 Ink pack 25 Pressure chamber 26 Ink supply valve 31 Float member 32 Permanent magnet 33 (33a, 33b) Hall element 41 Upper case 41a Cylindrical body 41b Inner cylindrical body 41d Contact part 42 Lower case 42a Space Portion 42b Connection pipe for pressurized air introduction 42c Connection pipe for pressurized air distribution 42d Stopper member 43 Diaphragm (pressure detector) 43a Thick portion 43b Thin portion 44 Movable member 44a Stopper member 44b Upright portion 44c Reflecting member 44d Step 45 Spring member 46 Sensor (output generating means) 46a Light source 46b Light receiving element

Claims (15)

[Claims] 1. A pressurized air generated by an air pressurizing pump is applied to a main tank in which ink is stored, and the ink is moved from the main tank to a recording head mounted on a carriage by the action of the pressurized air. In the ink jet recording apparatus configured to replenish, a pressure detector for detecting the pressure of the pressurized air is disposed in an air flow path between the air pressurizing pump and the main tank,
A diaphragm configured to control the driving of the air pressurizing pump based on a control signal generated by a pressure detected by the pressure detector, wherein the pressure detector has a diaphragm that is displaced by receiving an air pressure of pressurized air. And an output generating means for generating a control signal based on the amount of displacement of the diaphragm. 2. The main tank has an outer shell formed in an airtight state, and stores therein an ink pack formed of a flexible material in which ink is sealed, and includes an outer constituent member of the main tank and an ink pack. 2. The ink jet recording apparatus according to claim 1, wherein the pressurized air generated by the air pressurizing pump is applied to the pressure chamber formed by: 3. A configuration in which ink is supplied from the main tank to a sub-tank mounted on a carriage via an ink supply path, and ink is supplied from the sub-tank to the recording head mounted on the carriage. An ink jet recording apparatus according to claim 1. 4. The ink jet recording apparatus according to claim 3, wherein the ink supply path from the main tank to the sub tank is constituted by a flexible ink supply tube. 5. The output generating means includes: a movable member which is moved forward and backward by the displacement of the diaphragm; and a photosensor including a light source and a light receiving element arranged so as to cross a moving path of the movable member, 5. The ink jet recording apparatus according to claim 1, wherein said control signal is generated based on an output of a light receiving element constituting said photo sensor. 6. The output generating means receives a movable member moved forward and backward by the displacement of the diaphragm, a light source for projecting light on a movement path of the movable member, and a reflected light of the light source based on the movement of the movable member. 5. The ink-jet printing method according to claim 1, further comprising: a photosensor including a light-receiving element configured to generate the control signal based on an output of the light-receiving element included in the photosensor. apparatus. 7. The diaphragm is made of an elastic material, and the movable member is configured to move forward and backward based on a displacement of the diaphragm due to a balance between an air pressure received by the diaphragm and a return force of the diaphragm. The ink jet recording apparatus according to claim 5 or 6. And a spring member for urging the diaphragm in a returning direction, wherein the diaphragm is displaced based on a balance between an air pressure received by the diaphragm, a restoring force of the diaphragm and an urging force of the spring member. 7. The ink jet recording apparatus according to claim 5, wherein the movable member is configured to move forward and backward. 9. The ink jet recording apparatus according to claim 1, wherein said diaphragm is made of rubber. 10. The ink jet recording apparatus according to claim 1, wherein said diaphragm is made of rubber and cloth. 11. The ink jet recording apparatus according to claim 5, wherein a step portion for preventing excessive displacement of the diaphragm due to air pressure is formed on the movable member. 12. The ink jet recording apparatus according to claim 8, further comprising a stopper member that receives an urging force of the spring member and prevents an excessive displacement of the diaphragm. 13. The ink jet recording apparatus according to claim 5, wherein said movable member is formed integrally with said diaphragm. 14. A space portion for receiving air pressure from an air pressurizing pump is formed inside the case by arranging the diaphragm so as to close an opening of the case. An ink jet recording apparatus according to any one of the above. 15. A connection pipe for introducing pressurized air from an air pressurizing pump into a space, a pressurized air from the space, and a pressurized air to each main tank from the space. 15. The ink jet recording apparatus according to claim 14, wherein a plurality of connection pipes for distributing the pressurized air are formed.