JP2001253085A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control driving of an air pressurizing pump in a recorder where ink is supplied from an ink cartridge to the side of a recording head carried on a carriage by pneumatic pressure generated from an air pressurizing pump. SOLUTION: A pressure detector 23 for detecting the pressure of pressurized air is provided in an air channel between an air pressurizing pump 21 and an ink cartridge 9. The pressure detector 23 is arranged to detect a lower limit set pressure and an upper limit set pressure of pressurized air. When the pressure level detected by the pressure detector does not reach the lower limit set pressure, the air pressurizing pump 21 is controlled to be driven and when the pressure detector detects the upper limit set pressure, the air pressurizing pump 21 is controlled to be stopped. Consequently, a problem that driving and stoppage of the air pressurizing pump 21 is repeated frequently can be eliminated.

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 as an ink cartridge in which ink is stored. The present invention relates to an ink jet recording apparatus configured to supply ink to a recording head mounted on a carriage.

[0002]

2. Description of the Related Art An ink jet recording apparatus is generally mounted on a carriage and moves in the width direction of the recording paper, and relatively moves the recording paper in a direction perpendicular to the moving direction of the recording head. A paper feed unit for moving the recording paper is provided, and recording is performed on recording paper by discharging ink droplets from a recording head based on print data.

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 an increasing 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 and a motor for driving 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, a pressure detector for detecting the air pressure applied to each main tank is provided, and when this pressure detector detects a pressure equal to or less than a predetermined value, the pressurizing pump is driven, and the pressure detector detects a predetermined pressure. By controlling the operation of the pressurizing pump to stop when the pressure is detected, the air pressure applied to the main tank can be maintained in an appropriate range.

However, according to such a configuration, for example, when the consumption of the ink in the main tank proceeds slightly even based on a printing operation or the like, the pressure detector detects a pressure equal to or less than a predetermined value and drives the pressurizing pump. When the pressurizing pump is driven for a short time, the operation in which the pressure detector detects a predetermined pressure and stops driving the pressurizing pump is repeated. As described above, since the driving of the pressurizing pump is intermittently repeated at an extremely short time interval, for example, a problem that a user is suspected of a failure is caused.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems, and the air pressure applied to the main tank is always kept within an appropriate range while suppressing the frequent driving operation of the pressurizing pump. It is an object of the present invention to provide an ink jet recording apparatus configured to be able to manage.

[0013]

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, ink is supplied from a main tank to a recording head mounted on a carriage by the action of the pressurized air, wherein the air pressurizing pump and the main tank In the air flow path between, a pressure detector capable of detecting the lower limit set pressure and the upper limit set pressure of the pressurized air is disposed, and when the pressure detector detects that the lower limit set pressure has not been reached In addition, while controlling to drive the air pressurizing pump, when the pressure detector detects the upper limit set pressure, driving of the air pressurizing pump is stopped. It is configured to include a control means for controlling the so that.

In this case, preferably, ink is supplied from the main tank to a sub-tank mounted on the carriage via an ink supply path, and the sub-tank supplies ink to the recording head mounted on the carriage. It is composed of Preferably, the pressure detector includes a diaphragm that is displaced by receiving the air pressure of the pressurized air, and a lower limit set pressure and an upper limit set pressure of the pressurized air based on a displacement amount of the diaphragm to generate a control signal. An output generating means for generating is provided.

On the other hand, in a preferred embodiment, the output generating means comprises a movable member which is moved forward and backward by the displacement of the diaphragm, and a light source and a light receiving element which are respectively arranged so as to cross the moving path of the movable member. It comprises at least two sets of photosensors, based on the output of each light receiving element constituting the photosensor,
The lower limit set pressure and the upper limit set pressure of the pressurized air are detected.

In another preferred embodiment of the output generating means, the output member is based on a movable member which is moved forward and backward by a displacement of a diaphragm, a light source which projects light on a moving path of the movable member, and a movement of the movable member. A light receiving element for receiving the reflected light of the light source; and at least two sets of photo sensors. Based on the outputs of the respective light receiving elements constituting the photo sensor, the lower limit set pressure and the upper limit set pressure of the pressurized air Detection.

In any of the above structures, the diaphragm is made of an elastic material, and the movable member moves 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.

[0018] The diaphragm is preferably made of rubber. The diaphragm may be made of rubber and cloth. On the other hand, it is preferable that a stopper member for preventing excessive displacement of the diaphragm by receiving the urging force of the spring member is further provided. Further, it is preferable that a step portion for preventing excessive displacement of the diaphragm by air pressure is formed on the movable member.

The diaphragm is arranged so as to close the opening of the case, so that a space for receiving air pressure from an air pressurizing pump is formed inside the case. A connection pipe for introducing pressurized air from the pump into the space, and a plurality of connections for distributing pressurized air for distributing pressurized air from the space to each main tank. Preferably, a tube is formed.

On the other hand, preferably, the outer periphery of the main tank is formed in an airtight state, and an ink pack formed of a flexible material in which ink is sealed is housed therein. The pressurized air generated by the air pressurizing pump is applied to a pressure chamber formed by the ink pack. 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.

According to the ink jet recording apparatus having the above-described structure, the pressurized air generated by the pressurizing pump is applied to the main tank, so that the air pressure acts on the sub-tank mounted on the carriage. 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 performed.

The pressure detector detects the pressure of the pressurized air in the air flow path between the air pressurizing pump and the main tank, and controls when a predetermined lower limit pressure and upper limit set pressure are detected. Generate a signal. When the pressure of the pressurized air in the air flow path between the air pressurizing pump and the main tank has not reached the lower limit set pressure, the motor in the air pressurizing pump is driven based on the control signal. Is made. Thereby, when the pressure of the pressurized air increases and the pressure of the pressurized air in the air flow path reaches the upper limit set pressure, the driving of the motor in the air pressurizing pump is stopped based on the control signal. Is controlled as follows.

That is, pressurization is started when the pressure falls below the lower limit set pressure level detected by the pressure detector, and stopped when the pressure reaches the upper limit set pressure level detected by the pressure detector. Therefore, necessary and sufficient pressurized air can be accumulated in the air flow path from the pressurizing pump to the main tank. Then, when the pressurized air accumulated due to the consumption of the ink falls below the level of the lower limit set pressure by the pressure detector, pressurization is started again as described above.

Therefore, the necessary and sufficient pressurized air is accumulated in the air flow path from the pressurizing pump to the main tank, so that the pressurized air falls below the lower limit set pressure level detected by the pressure detector. It takes a certain amount of time to drop, and the problem that the pressurizing pump repeatedly starts and stops frequently can be solved.

[0025]

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 movement 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 period when the recording apparatus is at rest,
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 release valve 22, and further, is supplied from the pressure release valve 22 to 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 release valve 22 is connected to 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 a pressure detector 23 to be described later is connected to an air pressurizing pump 21.
To prevent a problem such as that the pressure pump 21 continues to be driven and an excessive air pressure is applied to the main tank 9 to damage an ink pack 24 described later. Works.

The pressure detector 23 detects the pressure of the air pressurized by the air pressurizing pump 21 and functions to control the driving of the air pressurizing pump 21. As will be described later in detail, the pressure detector 23 is configured to detect the lower limit set pressure and the upper limit set pressure of the pressurized air, and the pressure detector does not reach the lower limit set pressure. When detecting that, while controlling to drive the air pressurizing pump, when the pressure detector detects the upper limit set pressure, it is controlled to stop driving the air pressurizing pump. You.

As shown in FIG. 2, the main tank 9 has an outer shell formed in an airtight state, and an ink formed of a flexible material in which ink is sealed. 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 stored 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 electrical 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, and each sub-tank always stores a substantially constant range of ink.

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.

From each sub-tank 7, a valve 35 is provided.
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, and a semicircular cross section is formed between the thick portion 43a and the peripheral portion. The formed thin portion 43b is formed. 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 has 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 and the movable member 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 made in contact with the upper surface.

On the other hand, the lower case 42 receives pressurized air from the air pressurizing pump 21 at its lower bottom.
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. Note that FIG. 3 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. 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 diaphragm The movable member 44 is moved up and down based on the return force due to the elasticity of the diaphragm and the displacement of the diaphragm due to the balance with the urging force of the spring member 45.

As shown in part A in FIG. 3, the movable member 44 is formed with a step portion 44d for preventing the diaphragm 43 from being excessively displaced when receiving the pressurized air. ing. 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.

On the other hand, two sets of photosensors 46 and 47 constituting output generating means are arranged on the movement path of the tip of the upright portion 44b formed on the movable member 44. The photo sensors 46 and 47 are provided with light sources 46a and 47a and light receiving elements 46b and 47b, respectively, and are configured such that the light sources and the light receiving elements face each other. The first photo sensor 46 (hereinafter, also referred to as a lower limit pressure sensor) includes a movable member 44.
Is located at a position close to the upright portion 44b, that is, on the lower side as shown in FIG. The second photo sensor 47 (hereinafter also referred to as an upper limit pressure sensor) is located at a position away from the upright portion 44b of the movable member 44, that is, above the first photo sensor 46 as shown in FIG. Are located in

Therefore, when the pressurized air introduced into the space 42a in the pressure detector 23 has not reached the lower limit pressure, the light projected from the light source 46a in the lower limit pressure sensor 46 is transmitted to the light receiving element 46b. As a result, an electrical output is generated at the light receiving element 46b. Similarly, the projection light from the light source 47a in the upper limit pressure sensor 47 reaches the light receiving element 47b, and an electric output is generated in the light receiving element 47b.

When the pressure of the pressurized air introduced into the space 42a exceeds the lower limit pressure, the diaphragm 43 is displaced and the tip of the upright portion 44b is moved to the light source 46a of the lower limit pressure sensor 46. It acts so as to block the optical axis from to the light receiving element 46b. Further, when the pressure of the pressurized air introduced into the space 42a increases and reaches the upper limit set pressure, the diaphragm 43 is further displaced similarly, and the tip of the upright portion 44b is moved to the upper limit pressure. It acts to block the optical axis from the light source 47a to the light receiving element 47b in the sensor 47.

FIG. 5 shows an operation routine of the control means for controlling the driving of the air pressurizing pump 21 by using the pressure detector 23 having the above-mentioned operation. That is, in step S11, the above-described electrical output by the lower limit pressure sensor 46 in the pressure detector 23 is verified. In this step S11, the lower limit pressure sensor 46
Pressure detected value has not reached the lower limit set pressure (Lo
If determined to be w), the flow shifts to step S12, where control for driving the pressure pump 21 is performed.

Then, in the driving state of the pressurizing pump 21, the above-mentioned electric output from the upper limit pressure sensor 47 is verified as shown in step S13, and it is determined that the detected pressure value has reached the upper limit set pressure (High). Then, the process proceeds to step S14 to control the driving of the pressurizing pump 21 to be stopped. By this operation, the pressure pump 21
Sufficient air pressure is accumulated in the air flow path extending from the air to each main tank 9.

Then, the process returns to step S11, and the above-described electrical output from the lower limit pressure sensor 46 is verified. In this case, since the air flow from the pressurizing pump 21 to each of the main tanks 9 has sufficiently accumulated the air pressure exceeding the lower limit set pressure detected by the lower limit pressure sensor, it is determined as High, and the return is performed. Is done. Then, in step S11, the electrical output of the lower limit pressure sensor is continuously verified, and if it is determined that the pressure has dropped below the lower limit set pressure (Low) due to, for example, consumption of the ink by the printing operation, the step is performed as described above. The operation after S12 is executed.

When the driving of the pressurizing pump is started in step S12 and the verification result by the upper limit pressure sensor 47 in step S13 indicates that the upper limit set pressure is not reached (Low), As shown in step S15, the continuous driving time of the pressurizing pump is verified. In this step S15, it is verified whether or not the continuous driving time of the pressure pump has passed a predetermined time (B).

If it is determined that the predetermined time (B) has elapsed (Yes) while the state of the pressure detection in Step S13 remains Low, some trouble occurs in the pressurized air supply system. Can be regarded as having. In this case, for example, an error message indicating a supply failure is displayed on a display (not shown) arranged in the recording apparatus.

By employing the above operation sequence, a sufficient air pressure (upper limit set pressure) can be accumulated by one driving operation of the pressurizing pump 21. Therefore, a considerable time interval is required until the lower limit pressure sensor 46 detects a Low state due to a decrease in air pressure due to ink consumption or the like and drives the pressure pump 21 again. Frequent driving and stopping can be suppressed.

FIG. 6 is a sectional view showing a second embodiment of the pressure detector 23. As shown in FIG. FIG.
The configuration of the pressure detector 23 shown in FIG. 3 is the same as that of the embodiment shown in FIG. Therefore, parts corresponding to the representative parts shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the embodiment shown in FIG. 6, the lower limit pressure sensor 46 as the first photo sensor and the upper limit pressure sensor 47 as the second photo sensor respectively transmit light to the moving path of the upright portion 44b of the movable member. It is composed of light sources 46a and 47a for projecting, and light receiving elements 46b and 47b for receiving the reflected light of the light source based on the movement of the upright portion 44b. Therefore, in this configuration, it is desirable to use a white synthetic resin material having good reflection characteristics as the upright portion 44b.

According to the structure shown in FIG. 6, when the air pressurizing pump 21 is driven and the pressurized air reaches the lower limit set pressure, the tip of the upright portion 44b projects light from the light source 46a in the lower limit pressure sensor. The light is reflected toward the light receiving element 46b. The determination shown in step S11 in FIG. 5 is made based on the output of the light receiving element 46b.
Further, when the air pressurizing pump 21 is further driven to reach the upper limit set pressure, the tip of the upright portion 44b receives the projection light from the light source 47a in the upper limit pressure sensor, and
The light is reflected to the 7b side. The determination shown in step S13 in FIG. 5 is made based on the output of the light receiving element 47b.

In the embodiment of the pressure detector 23 shown in FIGS. 3 and 6 described above, the lower end of the inner cylindrical body 41b formed in the upper case 41 and the movable member 4
A coil-shaped spring member 45 is arranged between the inner bottom of the coil spring 4 and the upright portion 44 so as to wind the upright portion 44b. 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 is moved forward and backward based on the displacement of the diaphragm caused by 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. .

[0064]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the air flow path between the air pressurizing pump and the main tank has the lower limit set pressure of the pressurized air. A pressure detector capable of detecting an upper limit set pressure is arranged, and when the pressure detector detects that the lower limit set pressure has not been reached, control is performed to drive an air pressurizing pump, and When the pressure detector detects the upper limit set pressure, control means is provided to stop the driving of the air pressurizing pump, eliminating the problem that the air pressurizing pump frequently repeats driving and stopping. can do.

[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 flowchart showing a control routine for driving and controlling an air pressurizing pump using an output from a pressure detector.

FIG. 6 is a sectional view showing a second embodiment of the pressure detector.

[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 release 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 42 Lower case 42a Space 42b Pressurization Air introduction connection pipe 42c Pressurized air distribution connection pipe 42d Stopper member 43 Diaphragm 44 Movable member 44a Stopper member 44b Upright portion 44d Step portion 45 Spring member 46 First photosensor (lower limit pressure sensor) 47 Second photosensor (upper limit) Pressure sensor) 46a, 47a Light source 46b, 47b 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 pressurized air acts on a print head mounted on a carriage from the main tank. An ink jet recording apparatus configured to be supplied with ink, wherein a lower limit set pressure and an upper limit set pressure of pressurized air are detected in an air flow path between the air pressurizing pump and a main tank. Pressure detector is arranged, if the pressure detector detects that the lower limit set pressure has not been reached,
While controlling to drive the air pressurizing pump,
When the pressure detector detects an upper limit set pressure, the ink jet recording apparatus includes control means for controlling to stop driving of the air pressurizing pump. 2. A printer according to claim 1, wherein ink is supplied from said main tank to a sub-tank mounted on a carriage via an ink supply path, and ink is supplied from said sub-tank to said recording head mounted on said carriage. The ink jet recording apparatus according to claim 1. And a control signal for detecting a lower limit set pressure and an upper limit set pressure of the pressurized air based on a displacement amount of the diaphragm. The ink jet recording apparatus according to claim 1 or 2, further comprising an output generating means for generating the output. 4. The output generating means includes at least two sets of a photodetector comprising a movable member which is moved forward and backward by the displacement of the diaphragm, and a light source and a light receiving element which are respectively arranged so as to cross the moving path of the movable member. 4. The ink jet recording apparatus according to claim 3, comprising a sensor, wherein the lower limit set pressure and the upper limit set pressure of the pressurized air are detected based on the output of each light receiving element constituting the photo sensor. 5. 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. And at least two sets of photosensors, each based on an output of each photodetector constituting the photosensor.
4. The ink jet recording apparatus according to claim 3, wherein the lower limit set pressure and the upper limit set pressure of the pressurized air are detected. 6. The diaphragm is made of an elastic material, and the movable member is moved 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. An ink jet recording apparatus according to claim 3 or claim 5. 7. A spring member for biasing the diaphragm in a returning direction, further comprising: a diaphragm that is displaced by a balance between an air pressure received by the diaphragm, a returning force of the diaphragm, and a biasing force of the spring member. The ink jet recording apparatus according to claim 6, wherein the movable member is configured to move forward and backward. 8. The ink jet recording apparatus according to claim 3, wherein said diaphragm is made of rubber. 9. The ink jet recording apparatus according to claim 3, wherein said diaphragm is made of rubber and cloth. 10. The ink jet recording apparatus according to claim 7, further comprising a stopper member that receives an urging force of the spring member to prevent the diaphragm from being excessively displaced. 11. The ink jet recording apparatus according to claim 4, wherein a step portion for preventing excessive displacement of the diaphragm due to air pressure is formed on the movable member. 12. A space for receiving air pressure from an air pressurizing pump is formed inside the case by arranging the diaphragm so as to close the opening of the case. An ink jet recording apparatus according to any one of the above. 13. A connecting 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. 13. The ink jet recording apparatus according to claim 12, wherein a plurality of pressurized air distribution connection pipes for distributing the compressed air are formed. 14. The main tank has an outer shell formed in an airtight state, an ink pack formed of a flexible material in which ink is sealed therein, and an outer constituent member of the main tank and the ink pack. The pressurized air generated by the air pressurizing pump is applied to the pressure chamber formed by (1) and (2).
An ink jet recording apparatus according to any one of the above. 15. The ink jet recording apparatus according to claim 1, wherein the ink supply path from the main tank to the sub tank is constituted by a flexible ink supply tube.