JP3823670B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording head mounted on a carriage from a main tank by applying pressurized air generated by an air pressure pump to a main tank as an ink cartridge storing ink. The present invention relates to an ink jet recording apparatus configured to replenish ink on the side.
[0002]
[Prior art]
An ink jet recording apparatus generally includes an ink jet recording head that is mounted on a carriage and moves in the width direction of the recording paper, and a paper feeding unit that moves the recording paper in a direction perpendicular to the moving direction of the recording head. And recording is performed on the recording paper by ejecting ink droplets from the recording head based on the print data.
[0003]
A recording head capable of ejecting, for example, black, yellow, cyan, and magenta inks is mounted on the carriage, enabling not only text printing with black ink but also full-color printing by changing the ejection ratio of each ink. Yes.
[0004]
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. For example, a recording apparatus of a type in which a main tank is loaded into a mounting apparatus (cartridge holder) disposed on the apparatus main body side is provided.
[0005]
A sub tank is disposed on the carriage on which the recording head is mounted, and each main tank supplies ink to each sub tank via an ink supply tube, and each sub tank supplies ink to each recording head. Is configured to supply.
[0006]
[Problems to be solved by the invention]
Nowadays, there is an increasing demand for a large recording apparatus that can perform printing on a large paper surface and has a long carriage scanning distance. In such a printing apparatus, in order to improve the throughput, the number of nozzles is increasingly increased in the printing head. Furthermore, in order to improve throughput, it is possible to replenish ink sequentially from the main tank to each sub-tank mounted on the carriage while printing is performed, so that ink can be stabilized from each sub-tank to the recording head. And a recording apparatus that can be supplied.
[0007]
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 scanning distance of the carriage is inevitably large. Will increase. In addition, as described above, since the recording head has a large number of nozzles, the amount of ink consumed is large, and the dynamic pressure of the ink increases in each ink supply tube connected from the main tank to the sub tank. There is a technical problem of insufficient ink supply.
[0008]
As one means for solving such a problem, for example, air pressure is applied to the main tank side and a forced ink flow is generated from the main tank to the sub tank by the air pressure. A configuration for replenishing ink may be employed.
[0009]
When trying to adopt such a configuration, an air pressurizing pump for applying pressurized air to the main tank side is required. The air pressurizing pump can stably apply pressurized air to the main tank side by constantly driving the driving power supply to the recording apparatus when the power is turned on. Operation can be ensured.
[0010]
However, when the pressure pump is always driven, noise generated from the pressure pump and the motor driving the pressure pump becomes a problem, and the durability of the pressure pump is also a problem. Therefore, another problem of cost increase for these countermeasures also occurs. Therefore, a pressure detector for detecting the air pressure applied to each main tank is provided, and when the pressure detector detects a pressure below a predetermined value, the pressure pump is driven, and the pressure detector When the pressure is detected, the air pressure applied to the main tank can be maintained in an appropriate range by performing control to stop the driving of the pressurizing pump.
[0011]
However, according to such a configuration, for example, when the ink consumption in the main tank proceeds even slightly based on the printing operation, the pressure detector detects the pressure below a predetermined level to drive the pressure pump, and pressurizes When the pump is driven for a short time, the pressure detector detects a predetermined pressure and the operation of stopping the pressurizing pump is repeated. As described above, since the driving of the pressurizing pump is repeated intermittently at a very short time interval, there arises a problem that, for example, the user is suspected of having a failure.
[0012]
The present invention has been made to solve the technical problems as described above, and the air pressure applied to the main tank can always be managed 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 as described above.
[0013]
[Means for Solving the Problems]
In an ink jet recording apparatus according to the present invention made to achieve the above object, pressurized air generated by an air pressurizing pump is applied to a main tank in which ink is stored, and the compressed air An ink jet recording apparatus configured to supply ink from a main tank to a recording head mounted on a carriage by an action, wherein an air flow path between the air pressurization pump and the main tank includes: Pressurized air lower limit set pressure The following conditions and a pressure state higher than the lower limit set pressure Upper limit set pressure The above state A pressure detector that can detect the pressure is arranged, the pressure detector is set to the lower limit set pressure Detect the following conditions If so, while controlling to drive the air pressure pump, By increasing the pressure of pressurized air by driving the air pressure pump, The pressure detector is set to the upper limit pressure The above state Is detected, control means for controlling to stop the driving of the air pressurization pump is provided.
[0014]
In this case, preferably Under the action of the pressurized air, Ink is supplied from the main tank to the sub tank mounted on the carriage via the ink supply path. By storing the ink in the sub tank, For the recording head mounted on the carriage from the sub tank, Stored in the sub-tank It is configured to be supplied with ink. 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 of the pressurized air based on a displacement amount of the diaphragm. The following states And upper set pressure The above state An output generating means for detecting the signal and generating a control signal is provided.
[0015]
On the other hand, in a preferred embodiment, the output generating means includes at least two sets of a movable member that is advanced and retracted by the displacement of the diaphragm, and a light source and a light receiving element that are respectively arranged so as to traverse the movement path of the movable member. The lower limit set pressure of the pressurized air based on the output of each light receiving element constituting the photosensor The following states And upper set pressure The above state Is made to detect.
[0016]
In another preferred embodiment of the output generating means, a movable member that is advanced and retracted by a displacement of a diaphragm, a light source that projects light onto a moving path of the movable member, and the light source that is based on the movement of the movable member. It is composed of at least two sets of photosensors with a light receiving element that receives reflected light, and based on the output of each light receiving element constituting the photosensor, the lower limit set pressure of pressurized air The following states And upper set pressure The above state Is made to detect.
[0017]
In any of the configurations described above, the diaphragm is made of an elastic material, and the movable member is advanced and retracted 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. The made configuration can be adopted. The movable member further comprises a spring member that urges the diaphragm in the return direction, and the movable member is based on the displacement of the diaphragm due to the balance between the air pressure received by the diaphragm, the return force of the diaphragm, and the urging force of the spring member. It is also possible to adopt a configuration that is adapted to be advanced and retracted.
[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 is further provided to receive an urging force of the spring member and prevent excessive displacement of the diaphragm. Further, it is desirable that a stepped portion for preventing excessive displacement due to air pressure of the diaphragm is formed on the movable member.
[0019]
The diaphragm is arranged so as to close the opening of the case, so that a space for receiving air pressure from the air pressurization pump is formed inside the case. A connection pipe for introducing pressurized air for introducing pressurized air into the space, and a plurality of connection pipes for distributing pressurized air from the space to each main tank. It is desirable to be formed.
[0020]
On the other hand, the main tank is preferably formed in a hermetically sealed outer shape and contains an ink pack formed of a flexible material in which ink is sealed. The pressurized air generated by the air pressure pump is applied to the pressure chamber formed by 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.
[0021]
According to the ink jet recording apparatus having the above-described configuration, since the pressurized air generated by the pressure pump is applied to the main tank, the air pressure acts on the sub tank mounted on the carriage. An amount of ink can be replenished. And the pressurization state with respect to the main tank is monitored by the pressure detector arranged in the air flow path between the air pressurization pump and the main tank, and the pressurization pump is controlled by the control signal generated by this pressure detector. The drive control is executed.
[0022]
The pressure detector measures the pressure of pressurized air in the air flow path between the air pressurization pump and the main tank. detection And the lower limit set pressure set in advance The following states and The pressure is higher than the lower limit set pressure Upper limit set pressure The above state The detection If so, a control signal is generated. The pressure of the pressurized air in the air flow path between the air pressurization pump and the main tank is the lower limit set pressure. When the following conditions are detected The motor in the air pressurizing pump is driven based on the control signal. As a result, the pressure of the pressurized air rises, and the pressure of the pressurized air in the air flow path becomes the upper limit set pressure. The above state The detection In this case, the motor is controlled to be stopped in the air pressurization pump based on the control signal.
[0023]
That is, pressurization is started when the lower limit set pressure level detected by the pressure detector is not exceeded, and pressurization is stopped when the upper limit set pressure level detected by the pressure detector is reached. Therefore, necessary and sufficient pressurized air can be accumulated in the air flow path from the pressure pump to the main tank. Then, when the pressurized air accumulated by the consumption of the ink becomes equal to or lower than the lower limit set pressure level by the pressure detector, the pressurization is started again as described above.
[0024]
Accordingly, since necessary and sufficient pressurized air is accumulated in the air flow path from the pressure pump to the main tank, before the pressure air falls below the lower limit set pressure level detected by the pressure detector. This requires a considerable amount of time and can solve the problem that the pressurizing pump frequently repeats driving and stopping.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
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 the longitudinal direction of the paper feeding member 5, that is, in the width direction of the recording paper. It is configured to reciprocate in a certain main scanning direction. Although not shown in FIG. 1, an ink jet recording head 6 described later is mounted on the surface of the carriage 1 that faces the paper feeding member 5.
[0026]
The carriage 1 is equipped with 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 each ink in order to temporarily store each ink therein. Then, a flexible ink supply tube 10 constituting an ink supply path from main tanks 9a to 9d as ink cartridges loaded in a cartridge holder 8 disposed at the end of the apparatus with respect to the sub tanks 7a to 7d. , 10,..., Black, yellow, magenta, and cyan inks are supplied.
[0027]
On the other hand, a capping unit 11 capable of sealing the nozzle forming surface of the recording head is disposed in a non-printing area (home position) on the movement path of the carriage 1, and further on the upper surface of the capping unit 11. Is provided with a cap member 11a formed of a flexible material such as rubber that can seal the nozzle forming surface of the recording head. Then, when the carriage 1 moves to the home position, the nozzle forming surface of the recording head is sealed by the cap member 11a.
[0028]
The cap member 11a functions as a lid that seals the nozzle forming surface of the recording head and prevents the nozzle openings from drying during the rest period of the recording apparatus. Although not shown in the figure, one end of a tube in a suction pump (tube pump) is connected to the cap member 11a, and a negative pressure by the suction pump is applied to the recording head so that ink is discharged from the recording head. A cleaning operation for sucking and discharging is performed. Further, a wiping member 12 made of an elastic material such as rubber is disposed on the print 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.
[0029]
Next, FIG. 2 schematically shows the configuration of an ink supply system mounted on the recording apparatus shown in FIG. 1, and this ink supply system will be described with reference to FIG. 1 and 2, reference numeral 21 denotes an air pressurization pump, and the air pressurized by the air pressurization pump 21 is supplied to the pressure release valve 22, and further, a pressure detector from the pressure release valve 22. The compressed air is supplied to each of the main tanks 9a to 9d (shown as a representative symbol 9 in FIG. 2 and may be described as a representative symbol 9 in the following). It is configured to be.
[0030]
The pressure release valve 22 has a function of releasing the pressure and maintaining the air pressure applied to the main tanks 9a to 9d within a predetermined range when the air pressure pressurized by the air pressurizing pump 21 reaches an excessive state. Have. This is because some trouble occurs in the control system from the pressure detector 23 to be described later to the air pressurizing pump 21, the pressurizing pump 21 continues to be driven, and excessive air pressure is applied to the main tank 9 to be described later. This works to avoid problems such as damaging the ink pack 24.
[0031]
The pressure detector 23 detects the air pressure pressurized by the air pressure pump 21. detection And functions to control the driving of the air pressurizing pump 21. As will be described later in detail, this pressure detector 23 is a lower limit set pressure of pressurized air. The following conditions and pressure higher than the lower limit set pressure Upper limit set pressure The above state The pressure detector is configured to detect the lower limit set pressure. The following states The detection If so, while controlling to drive the air pressure pump, By increasing the pressure of pressurized air by driving the air pressure pump, The pressure detector is set to the upper limit pressure The above state Is detected, the control of the air pressurization pump is stopped.
[0032]
As shown in FIG. 2, the outline of the main tank 9 is formed in an airtight state, and an ink pack 24 formed of a flexible material encapsulating ink is contained therein. It is stored. A 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, the ink packs 24 stored in the main tanks 9a to 9d receive pressure from the pressurized air, and ink flows are generated from the main tanks 9a to 9d to the sub tanks 7a to 7d. It is configured as follows.
[0033]
The ink pressurized in the main tanks 9a to 9d passes through the ink supply valves 26, 26... And the ink supply tubes 10, 10,. The sub-tanks 7a to 7d mounted on the carriage 1 (represented by the reference numeral 7 in FIG. 2 as a representative and may be simply described as the reference numeral 7 in the following) may be supplied. Has been.
[0034]
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. Magnetoelectric conversion elements 33 a and 33 b typified by Hall elements are attached to the substrate 34 and 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 ink that generates an electrical output by the Hall elements 33a and 33b according to the magnetic force dose by the permanent magnet 32 according to the floating position of the float member. It constitutes a quantity detection means.
[0035]
Therefore, for example, when the amount of ink in the sub tank 7 decreases, the position of the float member 31 accommodated in the sub tank moves in the direction of gravity, and accordingly, the position of the permanent magnet 32 also moves in the direction of gravity. . Therefore, the electrical output of the Hall elements 33a and 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 is determined by the electrical output obtained by the Hall elements 33a and 33b. 26 is opened. Thereby, the ink pressurized in the main tank 9 is individually sent out to each sub tank 7 in which the ink amount is reduced.
[0036]
When the ink amount in the sub tank 7 reaches a predetermined capacity, the ink supply valve 26 is closed based on the electrical outputs of the Hall elements 33a and 33b. By repeating such operation, the ink is intermittently replenished from the main tank to the sub-tanks, so that a substantially constant range of ink is always stored in each sub-tank.
[0037]
As described above, each ink pressurized by the air pressure in the sub tank is supplied with ink to each sub tank based on the electrical output based on the position of each float member arranged in the sub tank. Therefore, the ink supply response can be improved, and the amount of ink stored in the sub tank is appropriately managed.
[0038]
Each sub tank 7 is configured to supply ink to the recording head 6 via a valve 35 and a tube 36 connected thereto, and is supplied to an actuator (not shown) of the recording head 6. Based on the print data, the ink droplets are ejected from the nozzle openings 6 a formed on the nozzle formation surface of the recording head 6. In FIG. 2, reference numeral 11 denotes the capping unit described above, and the tube connected to the capping unit 11 is connected to a suction pump (tube pump) (not shown).
[0039]
FIG. 3 is a cross-sectional view of the first embodiment of the pressure detector 23 described above. The pressure detector 23 includes an upper case 41 whose outer shape is formed in a cylindrical shape, and a lower case 42 whose outer shape is also formed in a cylindrical shape, and between the upper case 41 and the lower case 42. The diaphragm 43 formed in a disk shape by a flexible elastic member is arranged in a form in which the peripheral edge is sandwiched.
[0040]
As shown in FIG. 3, the diaphragm 43 has a thick portion 43a formed at the center thereof, and a thin wall having a semicircular cross section between the thick portion 43a and the peripheral portion. A portion 43b is formed. The diaphragm 43 is preferably made of a rubber material. In addition, the diaphragm 43 may be formed in a state in which a cloth is filled with a rubber material. In this case, durability as a diaphragm can be enhanced.
[0041]
On the other hand, a cylindrical body 41a is formed integrally with the upper portion of the upper case 41, and an inner cylindrical body 41b is formed integrally with the cylindrical body 41a on the further inner upper portion of the cylindrical body 41a. . In the cross-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 circumferential direction with respect to the state shown in the figure. It is coupled to the cylinder 41a at a position. In other words, as shown in the figure, a pair of openings 41c are formed between the cylindrical body 41a and the inner cylindrical body 41b so as to face each other.
[0042]
A movable member 44 is accommodated inside the cylindrical body 41a 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-like stopper member 44a is formed at each tip portion. The stopper member 44a enters the opening 41c, and an upper end portion of the cylindrical body 41a. It is comprised so that it may engage with.
[0043]
The movable member 44 is formed with an upright portion 44b that is integrally raised from the inner bottom thereof. In the embodiment shown in FIG. 3, the lower end portion of the inner cylindrical body 41b and the inner portion of the movable member 44 are formed. Between the bottom portion, a coiled spring member 45 is disposed so as to equip the standing portion 44b. With this configuration, the movable member 44 is configured to be urged downward in the drawing by the spring member 45, so that the lower bottom portion of the movable member 44 is formed by the thick portion 43 a at the center of the diaphragm 43. It is in contact with the top surface.
[0044]
On the other hand, the lower case 42 has a connection for introducing pressurized air from the air pressurizing pump 21 to the space 42a between the lower case 42 and the diaphragm 43 at the lower bottom thereof. A pipe 42b and a plurality of pressurized air distribution connecting pipes 42c for distributing pressurized air from the space 42a to the main tanks 9 are formed. In this embodiment, the four main tanks 9 are provided as described above. In this case, four connection pipes 42c for distributing pressurized air are provided according to the number of the connection tanks 42c. Note that FIG. 3 shows two connection pipes 42c for distributing pressurized air, because this is shown in a sectional view.
[0045]
With this configuration, the pressurized air from the air pressurizing pump 21 is introduced into the space portion 42a of the pressure detector 23 via the connecting pipe 42b for introducing pressurized air, and the connecting pipe for distributing each pressurized air. It acts so that pressurized air is applied to the pressure chamber 25 in each main tank 9 via 42c. In response to the action of the pressurized air introduced into the space portion 42a, the diaphragm 43 is displaced upward in the figure and acts to push up the movable member 44 upward. A space formed between the diaphragm 43 and the upper case 41 is communicated with the atmosphere through a gap between the cylindrical body 41 a and the movable member 44.
[0046]
In this embodiment, as described above, the movable member 44 is configured to be urged downward in the figure by the spring member 45, and accordingly, the air pressure received by the diaphragm 43 and the elasticity of the diaphragm. The movable member 44 is moved up and down based on the displacement of the diaphragm due to the balance between the return force and the biasing force of the spring member 45.
[0047]
3, the movable member 44 is formed with a stepped portion 44d for preventing the diaphragm 43 from being excessively displaced when pressurized air is received. In order to explain this configuration and operation, the portion A in FIG. 3 is shown in an enlarged manner in FIG. That is, the diagram shown in the upper half of FIG. 4 shows a state in which the diaphragm receives normal or lower air pressure, and the diagram shown in the lower half of FIG. 4 shows that the diaphragm has an air pressure exceeding a predetermined level. The received state is shown.
[0048]
As shown in FIG. 4, when the diaphragm changes from the normal or lower air pressure state to the predetermined air pressure state or more, the movable member 44 moves upward in the figure, A stepped portion 44d formed on an upright portion 44b erected integrally from the inner bottom portion of the movable member 44 abuts against the abutting portion 41d constituting the lower end portion of the inner cylindrical body 41b, thereby preventing further elevation of the movable member 44. Is configured to do. Thereby, it is possible to avoid the diaphragm 43 from being excessively displaced, and a normal function as the pressure detector 23 is ensured.
[0049]
Further, in the embodiment shown in FIG. 3, the movable member 44 is formed in a bifurcated shape, and a claw-like stopper member 44a is disposed at each tip, so that the stopper member 44a is a cylindrical body 41a. The diaphragm 43 is configured not to be excessively displaced by the spring member 45 by engaging with the upper end portion of the spring member 45. However, when the claw-shaped stopper member 44a as described above is not formed, a cylindrical stopper member 42d is integrally formed at the center of the lower bottom portion of the lower case 42 as indicated by an imaginary line, thereby It is desirable to act to prevent excessive displacement.
[0050]
On the other hand, two sets of photosensors 46 and 47 constituting output generating means are arranged on the moving path of the tip of the upright portion 44b formed on the movable member 44. The photosensors 46 and 47 include light sources 46a and 47a and light receiving elements 46b and 47b, respectively, and are configured such that the light source and the light receiving element face each other. The first photosensor 46 (hereinafter also referred to as a lower limit pressure sensor) is disposed at a position close to the upright portion 44b in the movable member 44, that is, as shown in FIG. Further, the second photosensor 47 (hereinafter also referred to as an upper limit pressure sensor) is located at a position away from the upright portion 44b in the movable member 44, that is, above the first photosensor 46 as shown in FIG. Is arranged.
[0051]
Therefore, the pressurized air introduced into the space 42a in the pressure detector 23 is the lower limit set pressure. It is in the following state In this case, the projection light from the light source 46a in the lower limit pressure sensor 46 reaches the light receiving element 46b, and an electrical output is generated in the light receiving element 46b. Similarly, the projection light from the light source 47a in the upper limit pressure sensor 47 also reaches the light receiving element 47b, and an electrical output is generated in the light receiving element 47b.
[0052]
Further, when the pressurized air introduced into the space 42 a exceeds the lower limit set pressure, the diaphragm 43 is displaced and the tip of the upright portion 44 b is moved from the light source 46 a to the light receiving element in the lower limit pressure sensor 46. It acts to block the optical axis reaching 46b. Further, when the pressure of the pressurized air introduced into the space portion 42a increases to reach the upper limit set pressure, the diaphragm 43 is further displaced in the same manner, and the tip portion of the upright portion 44b becomes the upper limit pressure. The sensor 47 acts to block the optical axis from the light source 47a to the light receiving element 47b.
[0053]
FIG. 5 shows an operation routine of a control means for driving and controlling the air pressurization pump 21 using the pressure detector 23 having the above-described action. That is, in step S11, the electrical output described above by the lower limit pressure sensor 46 in the pressure detector 23 is verified. In step S11, the pressure detected by the lower limit pressure sensor 46 is the lower limit set pressure. It is in the following state When it is determined (Low), the process proceeds to step S12, and control for driving the pressurizing pump 21 is performed.
[0054]
Then, in the driving state of the pressurizing pump 21, the electric output described above by the upper limit pressure sensor 47 is verified as shown in step S13, and the detected pressure value is the upper limit set pressure. It is the above state If it is determined (High), control proceeds to step S14 to stop driving the pressurizing pump 21. By this operation, sufficient air pressure is accumulated in the air flow path from the pressurizing pump 21 to each main tank 9.
[0055]
Then, the process returns to step S11 again, and the above-described electrical output by the lower limit pressure sensor 46 is verified. In this case, since the air pressure sufficiently exceeding the lower limit set pressure detected by the lower limit pressure sensor is accumulated in the air flow path from the pressurizing pump 21 to each main tank 9, it is determined as High and the return Is done. Then, in step S11, the electrical output from the lower limit pressure sensor is continuously verified, and when it is determined that the pressure is lower (Low) than the lower limit set pressure due to, for example, ink consumption by the printing operation, the step is performed as described above. The operations after S12 are executed.
[0056]
Note that the driving of the pressurizing pump is started in step S12 described above, and the verification result by the upper limit pressure sensor 47 in step S13 is the upper limit set pressure. It is in the following state If it is determined (Low), the continuous drive time of the pressurizing pump is verified as shown in step S15. In this step S15, it is verified whether or not the continuous drive time of the pressure pump has passed a predetermined time (B).
[0057]
If it is determined that the predetermined time (B) has elapsed (Yes) while the pressure detection state in Step S13 remains Low, some failure has occurred in the pressurized air supply system. Can be considered. In this case, for example, an error message indicating a supply failure is displayed on a display (not shown) arranged in the recording apparatus.
[0058]
By adopting the operation sequence as described above, a sufficient air pressure (upper limit set pressure) can be accumulated by a single drive operation of the pressure pump 21. Accordingly, due to a decrease in air pressure due to ink consumption or the like, a considerable time interval is left before the lower limit pressure sensor 46 detects the Low state and the pressure pump 21 is driven again. The repeated action of frequent driving and stopping can be suppressed.
[0059]
Next, FIG. 6 shows a second embodiment of the pressure detector 23 in a sectional view. Note that the pressure detector 23 shown in FIG. 6 has the same configuration as that shown in FIG. 3 except for the portion of the photosensor 46. Therefore, parts corresponding to the representative parts shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0060]
The lower limit pressure sensor 46 as the first photosensor and the upper limit pressure sensor 47 as the second photosensor in the form shown in FIG. 6 are light sources that project light onto the moving path of the upright portion 44b of the movable member. 46a, 47a and light receiving elements 46b, 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 with good reflection characteristics as the upright portion 44b.
[0061]
According to the configuration shown in FIG. , Pressurized air is the lower limit set pressure In the following conditions: The tip of the upright portion 44b is projected light from the light source 46a in the lower limit pressure sensor. Is received Reflected to the optical element 46b side It will be in a state that does not. Based on the output of the light receiving element 46b, the determination shown in step S11 of FIG. 5 is made. The air pressurizing pump 21 Gadget When moved 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 reflects it to the light receiving element 47b side. Based on the output of the light receiving element 47b, the determination shown in step S13 of FIG. 5 is made.
[0062]
In the embodiment of the pressure detector 23 shown in FIG. 3 and FIG. 6 described above, both are provided between the lower end of the inner cylindrical body 41b formed in the upper case 41 and the inner bottom portion of the movable member 44. A coiled spring member 45 is arranged so as to equip the upright portion 44b. However, even in the configuration excluding the spring member 45, the pressure detector 23 having the same function can be configured.
[0063]
In this case, the movable member is configured to move forward and backward based on the displacement of the diaphragm due to the balance between the restoring force of the diaphragm 43 made of an elastic material and the air pressure received by the diaphragm. Therefore, when such a configuration is adopted, the lower bottom portion of the movable member 44 is bonded to the upper surface of the thick portion 43a of the diaphragm 43, or the thick portion 43a of the diaphragm 43 is the movable member. It is necessary to be formed integrally with the lower bottom portion of 44 and mechanically connected to each other.
[0064]
【The invention's effect】
As apparent from the above description, according to the ink jet recording apparatus of the present invention, the lower limit set pressure and the upper limit set pressure of the pressurized air are detected in the air flow path between the air pressurization pump and the main tank. A pressure detector that can be arranged, said pressure detector is the lower limit set pressure The following states The detection In such a case, the air pressure pump is controlled to be driven, and the pressure detector The above state Since the control means for controlling to stop the driving of the air pressurization pump is provided, the problem that the air pressurization pump repeatedly drives and stops can be solved.
[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 cross-sectional view showing a first embodiment of a pressure detector used in the ink supply system shown in FIG. 2;
4 is an enlarged cross-sectional view showing a part of the configuration 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 cross-sectional view showing a second embodiment of the pressure detector.
[Explanation of symbols]
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 pressurization 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 cylinder
42 Lower case
42a space
42b Connecting pipe for introducing pressurized air
42c Connecting pipe for distributing pressurized air
42d Stopper member
43 Diaphragm
44 Movable members
44a Stopper member
44b Standing part
44d Stepped part
45 Spring member
46 1st photo sensor (lower limit pressure sensor)
47 Second Photosensor (Upper Pressure Sensor)
46a, 47a Light source
46b, 47b Light receiving element

Claims (15)

Pressurized air generated by an air pressurizing pump is applied to the main tank in which ink is stored, and ink is supplied from the main tank to the recording head mounted on the carriage by the action of the pressurized air. An ink jet recording apparatus configured as described above,
Wherein the air flow path between the air pressurization pump and the main tank, for detecting the lower limit set pressure following the state of pressurized air, an upper limit set pressure or more states a higher pressure state than the set lower limit pressure A pressure detector capable of being arranged, and when the pressure detector detects a state below a lower limit set pressure, the air pressure pump is controlled to be driven and the air pressure pump is driven. An ink jet recording apparatus comprising control means for controlling to stop driving of an air pressurizing pump when the pressure detector detects a state of an upper limit set pressure or more due to an increase in pressure of pressurized air . Under the action of the pressurized air, ink is supplied from the main tank to the sub tank mounted on the carriage via the ink supply path, so that the ink is stored in the sub tank and is mounted on the carriage from the sub tank. The ink jet recording apparatus according to claim 1, wherein the ink stored in the sub tank is supplied to the recording head. The pressure detector detects and controls a diaphragm that is displaced by receiving the air pressure of the pressurized air, and a state that is lower than the lower limit set pressure of the pressurized air and a state that is higher than the upper limit set pressure based on the displacement amount of the diaphragm. 3. An ink jet recording apparatus according to claim 1, further comprising output generating means for generating a signal. The output generating means is composed of at least two sets of photosensors including a movable member that is advanced and retracted by the displacement of the diaphragm, and a light source and a light receiving element that are respectively arranged so as to traverse the movement path of the movable member, The ink jet recording apparatus according to claim 3, wherein a state where the pressurized air is below a lower limit set pressure and a state above an upper limit set pressure is detected based on an output of each light receiving element constituting the photosensor. . The output generating means includes a movable member that is advanced and retracted by displacement of the diaphragm, a light source that projects light onto a movement path of the movable member, and a light receiving element that receives reflected light of the light source based on the movement of the movable member. It is composed of at least two sets of photosensors, and is configured to detect a state below the lower limit set pressure of pressurized air and a state above the upper limit set pressure based on the outputs of the respective light receiving elements constituting the photosensor. The ink jet recording apparatus according to claim 3. The said diaphragm is comprised with the elastic material, The said movable member is comprised so that the said movable member may be advanced or retracted based on the displacement of the diaphragm by the balance of the air pressure which the said diaphragm receives, and the restoring force of a diaphragm. 2. An ink jet recording apparatus according to 1. A spring member that urges the diaphragm in the return direction is further provided, 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, the return force of the diaphragm, and the urging force of the spring member. The ink jet recording apparatus according to claim 6, configured as described above. The ink jet recording apparatus according to any one of claims 3 to 7, wherein the diaphragm is made of rubber. 8. The ink jet recording apparatus according to claim 3, wherein the diaphragm is made of rubber and cloth. The ink jet recording apparatus according to claim 7, further comprising a stopper member that receives an urging force of the spring member and prevents excessive displacement of the diaphragm. 11. The ink jet recording apparatus according to claim 4, wherein the movable member is formed with a step portion that prevents excessive displacement of the diaphragm due to air pressure. The space part which receives the air pressure from an air pressurization pump is formed in the inside of a case by arrange | positioning the said diaphragm so that the opening part of a case may be obstruct | occluded. Inkjet recording device. The case has a plurality of connecting pipes for introducing pressurized air from the air pressurizing pump into the space, and a plurality of pipes for distributing the pressurized air from the space to the main tanks. The ink jet recording apparatus according to claim 12, wherein a connection pipe for distributing pressurized air is formed. The main tank is formed of an outer shell constituting member of the main tank and an ink pack, and an ink pack formed of a flexible material in which ink is sealed is housed. The ink jet recording apparatus according to any one of claims 1 to 13, wherein pressurized air generated by the air pressurizing pump is applied to a pressure chamber. The ink jet recording apparatus according to claim 1, wherein an ink supply path from the main tank to the sub tank is configured by a flexible ink supply tube.

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