JP3133866B2 - Recording apparatus and ink detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, and more particularly, to an ink jet printer for recording by discharging ink and an ink detecting method using the ink jet printer.

[0002]

2. Description of the Related Art Inkjet printers have become widespread as printers having low noise, low running cost, small size and high recording speed. As such an ink jet printer, an ink heating type ink jet printer that applies thermal energy to ink stored in nozzles to generate bubbles and urges and discharges ink by its kinetic energy has been proposed.

Conventionally, in a printer using a liquid ink, such as an ink jet printer, there has been a method described below as a method for discriminating out of ink and informing an operator. 1) Visual Inspection This is a method in which the ink tank is made of a transparent member, and the operator visually checks the remaining amount of ink.

2) A method of passing a current between electrodes provided in an ink tank When a conductive ink is used, the resistance value greatly differs between the case where the electrode is in the ink and the case where the electrode is in contact with air outside the ink. Therefore, the presence or absence of ink in the ink tank can be detected by applying a predetermined voltage between the electrodes at regular intervals and detecting a change in the resistance value.

3) Optical detection method A float floating in the ink is provided in the ink tank, and a light emitting element and a light receiving element are provided on the wall surface of the ink tank so as to face each other so that the optical axes of the two elements coincide. While the ink is sufficient, the light beam of the light emitting element reaches the light receiving element through the transparent wall of the ink tank and the ink. When the amount of ink decreases by a certain amount or more, the float interrupts the optical axis, and the signal of the light receiving element is not output. Therefore, the out of ink can be detected.

4) Mechanical Contact Method A detecting member 33 as shown in FIG. 2 is provided in the middle of the path from the ink tank to the recording head. The detection member 33 has a container shape, and ink is stored therein. In the figure, a diaphragm rubber 34 seals so that ink below the detecting member 33 does not leak to the upper part. A contact A35 is provided at one location on the lower surface of the diaphragm rubber. A contact B36 exists at a position on the detection member opposite to the contact A35. The diaphragm rubber 34 is fixed to a shaft 37, which can move up and down. When there is ink, the shaft 37 is urged upward by a spring 38. The ink is supplied to the head from the head tube 40 via the detection member from the tank tube 39. The tip of the tank tube 39 is connected to an unillustrated gas-tight bag-made ink tank. When the ink in the ink tank runs out, the bag-made ink tank first contracts,
Thereafter, the diaphragm moves downward by the negative pressure. As a result, the contacts A and B come into contact. Therefore, the presence or absence of ink can be detected by periodically applying a voltage between the contacts A and B from an unillustrated electric wire and checking the continuity.

When the above-described ink detection method is applied to the above-described ink heating type ink jet printer, there are the following problems. First, the visual method 1) is a simple and reliable method. However, depending on the form of the printer, there is a case where the operator has to place the tank at a position that is difficult to see due to the exterior, and there is always a degree of freedom. Not a way. In particular, in the case of a printer having a plurality of ink tanks such as a color printer, in order to visually check the presence or absence of ink of all colors, it is necessary to see the contents of each tank from a direction in which the contents of each tank can be checked, which is also practical Not a way. Further, in order to prevent the deterioration of the ink, a material that is not transparent may be used as a material constituting the tank, and there is a disadvantage that the applicable range is limited.

[0008] The method 2) in which the current is passed through the ink has a disadvantage that the ink is electrolyzed and deteriorates. In the case of a color printer, it is necessary to provide a pair of electrodes for each color ink. Further, in the case of an ink cartridge type in which a recording head and an ink tank (cartridge) are integrated, if electrodes are provided in the cartridge, running costs will increase. In order to avoid this, even if an electrode is not provided on the cartridge and an electrode is provided in the middle of the path from the cartridge to the head, it is difficult to place the electrode due to space limitations. Therefore, in the case of an ink cartridge type printer as in the above-described conventional example, this method is not an appropriate method.

The optical method 3) requires a light-emitting element, a light-receiving element, and a float, and tends to be large, and it is difficult to apply the method to a small-sized printer. It is difficult to apply the mechanical contact method of 4) for the same reason as the method of 2).
In the methods 2) to 4), a special device is required. In the case of a printer having a plurality of ink tanks such as a color printer, the devices must be provided in the same number as the number of tanks. Reduction was difficult.

For this reason, in order to detect the ink shortage in the ink-heating type ink jet printer, the operator judges that the ink has run out, and replaces the tank when the ink cannot be ejected from the nozzles.

[0011]

However, if the printer becomes unable to print, the operator cannot determine whether the apparatus is out of print or the ink has run out until the ink cartridge is replaced with a new one and printing is performed. There were drawbacks. In addition, since it is not possible to recognize in advance that the ink has run out, the ink may run out during the recording of the image,
To avoid this, the operator must know the amount of ink used based on the recorded amount and the like.

[0012] Even if the ink is not out of ink, if air is sucked into the head of the ink jet printer, the same state as the ink out may occur, and a recording failure may occur. SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional example, and has as its object to provide a recording apparatus and an ink detection method that can easily and reliably detect the presence or absence of ink without using special parts.

[0013]

To achieve the above object, the recording apparatus of the present invention has the following configuration. A recording apparatus that performs recording using a recording head that ejects the ink by applying thermal energy to the ink,
An information value Tr corresponding to the amount of temperature change of the recording head when applying predetermined thermal energy to the ink to such an extent that the recording head does not eject ink, and a predetermined thermal energy to such an extent that the recording head ejects ink. Detecting means for detecting an information value T corresponding to the amount of temperature change of the recording head when the ink is applied to the ink; and a ratio T / Tr of Tr and T detected by the detecting means.
And a determining unit for determining whether there is a sufficient amount of ink in the recording head by comparing the predetermined reference value Raf with a predetermined reference value Raf. The information value Tr ′ corresponding to the amount of temperature change of the predetermined recording head when the predetermined heat energy is applied to the ink, and the predetermined heat energy enough to discharge the ink from the predetermined recording head are applied to the ink. The ratio of the information value corresponding to the temperature change amount of the predetermined recording head when the ink is present in the predetermined recording head to the information value Ta corresponding to the temperature change amount of the predetermined recording head when T
a / Tr ′, and an information value corresponding to the amount of temperature change of the predetermined recording head when the predetermined thermal energy enough to discharge the ink from the predetermined recording head is applied to the ink. When the ratio between the information value Ta ′ corresponding to the temperature change amount when there is no ink in the predetermined recording head and Ta ′ / Tr ′, the reference value Raf is:
The Ta / Tr '<the reference value Raf <the Ta' / T
r ', and when the determination means determines that T / Tr <the reference value Raf, it is determined that there is a sufficient amount of ink in the recording head. Value Raf <T / T
When it is determined that r, it is determined that there is not enough ink in the recording head. Alternatively, in a recording apparatus that performs recording using a recording head that ejects the ink by applying thermal energy to the ink, when a predetermined amount of thermal energy that does not eject the ink from the recording head is applied to the ink. A first information value corresponding to the temperature change amount of the recording head, and a first information value corresponding to the temperature change amount of the recording head when predetermined thermal energy is applied to the ink such that the ink is ejected from the recording head. Detecting means for detecting the information value of the second information value, the ink in the recording head based on the first information value and the second information value detected by the detecting means, and a predetermined reference value. Determining means for determining whether there is a sufficient amount, wherein the recording head has a plurality of liquid paths, and a plurality of types of ink are supplied to corresponding liquid paths for each ink. The detecting means applies energy to each of the liquid paths corresponding to each of the plurality of types of ink to detect an information value corresponding to a temperature change amount of a recording head. It is determined whether or not there is a sufficient amount of ink for each liquid path corresponding to each of the inks. Alternatively, in a recording apparatus that performs recording using a recording head that ejects the ink by applying thermal energy to the ink, when a predetermined amount of thermal energy that does not eject the ink from the recording head is applied to the ink. A first information value corresponding to the temperature change amount of the recording head, and a first information value corresponding to the temperature change amount of the recording head when predetermined thermal energy is applied to the ink such that the ink is ejected from the recording head. Detecting means for detecting the information value of the second information value, the ink in the recording head based on the first information value and the second information value detected by the detecting means, and a predetermined reference value. Determining means for determining whether there is a sufficient amount, wherein the recording head has a plurality of liquid paths, and a plurality of types of ink are supplied to corresponding liquid paths for each ink. Are, the decision means has a plurality of reference values in accordance with the number of liquid paths corresponding to said plurality of types of inks,
Based on the reference value and the first information value and the second information value, it is determined whether there is a sufficient amount of ink.

The ink detecting method of the present invention has the following configuration. An ink detection method for detecting ink in a recording head that ejects the ink by applying thermal energy to the ink, the method including: applying a predetermined amount of thermal energy to the ink such that the ink is not ejected from the recording head. The information value Tr corresponding to the temperature change amount of the recording head and the information value T corresponding to the temperature change amount of the recording head when a predetermined thermal energy such that the ink is ejected from the recording head are applied to the ink. Detecting a sufficient amount of ink in the recording head by comparing a ratio T / Tr between the Tr and the T detected in the detecting process with a predetermined reference value Raf. A determination step for determining whether or not there is any ink, by applying a predetermined heat energy to the ink such that the ink is not ejected from a predetermined recording head. The information value Tr ′ corresponding to the temperature change amount of the predetermined print head when the predetermined print head is applied, and the predetermined print head when the predetermined heat energy enough to discharge the ink from the predetermined print head is applied to the ink. Where Ta / Tr ′ is the information value corresponding to the temperature change amount and Ta / Tr ′, which is the information value corresponding to the temperature change amount when ink is present in the predetermined printhead.
And an information value corresponding to a temperature change amount of the predetermined recording head when applying predetermined thermal energy to the ink to such an extent that ink is ejected from the predetermined recording head, wherein the information value is included in the predetermined recording head. Assuming that the ratio of the information value Ta ′ corresponding to the temperature change amount when there is no ink is Ta ′ / Tr ′, the reference value Raf is Ta / Tr ′ <the reference value Raf <the Ta ′ / Tr ′. The value T / Tr <the reference value Ra is determined by the determination means.
f, it is determined that there is a sufficient amount of ink in the printhead, and when the determination means determines that the reference value Raf <the T / Tr, the ink in the printhead is determined. Is determined to be insufficient. Alternatively, there is provided an ink detection method for detecting ink in a recording head that ejects the ink by applying thermal energy to the ink, wherein a predetermined thermal energy is applied to the ink such that the ink is not ejected from the recording head. The first information value corresponding to the temperature change amount of the recording head at the time and the temperature change amount of the recording head when a predetermined thermal energy of such a level that the ink is ejected from the recording head is applied to the ink. A detecting step for detecting a second information value; an ink in the recording head based on the first information value and the second information value detected in the detecting step; and a predetermined reference value. The recording head has a plurality of liquid paths, and a plurality of types of ink correspond to each ink. And supplying the energy to each of the liquid paths corresponding to each of the plurality of types of inks to detect an information value corresponding to a temperature change amount of the recording head, and in the determining step, It is determined whether there is a sufficient amount of ink for each of the liquid paths corresponding to the plurality of types of ink. Alternatively, there is provided an ink detection method for detecting ink in a recording head that ejects the ink by applying thermal energy to the ink, wherein a predetermined thermal energy is applied to the ink such that the ink is not ejected from the recording head. The first information value corresponding to the temperature change amount of the recording head at the time and the temperature change amount of the recording head when a predetermined thermal energy of such a level that the ink is ejected from the recording head is applied to the ink. A detecting step for detecting a second information value; an ink in the recording head based on the first information value and the second information value detected in the detecting step; and a predetermined reference value. A determination step for determining whether there is a sufficient amount, the recording head has a plurality of liquid paths,
A plurality of types of inks are supplied to corresponding liquid paths for each ink, and have a plurality of reference values according to the number of liquid paths corresponding to the plurality of types of inks. It is determined based on the first information value and the second information value whether or not there is a sufficient amount of ink.

[0015]

First Embodiment As a first embodiment of the present invention, a description will be given of a color ink-jet printer of the type in which thermal energy is applied to ink to vaporize the ink, whereby the ink is urged to be discharged and recorded. <Structure of Apparatus> FIG. 1 is a perspective view showing the entire ink jet printer of this embodiment.

The ink jet head 1, the black ink cartridge 4 and the color ink cartridge 5 are fixed to a carriage 7. The carriage 7 is supported by a guide A10 and a guide B11,
Can reciprocate in any direction. At this time, the ejection surface of the head 1 moves while maintaining a clearance of 1 mm from the recording paper 6. The lead screw 9 is connected to a motor (not shown) and rotates. A lead pin (not shown) projecting from the carriage 7 is engaged with the lead screw 9, and the carriage 7 reciprocates in accordance with the rotation of the screw 9.

The recording paper 6 is sandwiched between a paper feed roller 8 and a pinch roller (not shown), and is fed in the direction of arrow 15. Further, the recording paper 6 is sandwiched between a paper discharge roller 12 and a spur 16,
A tension is applied between the paper discharge roller 12 and the paper feed roller 8 and the paper is held on a plane. The purge unit 13 has a function of sucking ink from a head ejection port. The ink sucked from the nozzles of the head 1 is discarded into a waste ink tank (not shown). The purge unit 13 also waits for the role of receiving the preliminary ejection ink described later. A cap rubber (not shown) is provided on the head-facing surface of the purge unit 13, and when the power is off, the head 1 is pressed against the cap rubber to prevent the ink in the nozzles from drying.

Next, the recording operation of the apparatus will be described. When the apparatus is started, the head discharge port is pressed against the cap rubber. Next, the recording paper 6 is fed to the recording start position.
After the purge unit 13 retreats from the head 1, an ink presence / absence detection sequence described below is performed. After detection, if it is determined that there is no black or color ink,
The operator is warned by display means such as an LED and a liquid crystal (not shown). When the ink cartridge is replaced, the ink is suctioned by the purge unit 13, the detection sequence is performed again, and it is determined that there is ink, and then the warning display is turned off.

Next, when a recording signal is input, the carriage 7 scans and performs ink ejection at a timing of 360 dots per inch. At this time, 64 black nozzles are used for character recording, and 24 nozzles inside the black nozzles are used for graphic printing. When recording of one line is completed, the recording paper is sent for 64 dots for character printing and 24 dots for graphic printing. Thereafter, printing for one page is performed in the same manner, and the sheet is discharged. If printing is continued, a new sheet is fed. If not, the carriage moves to the front of the purge unit, the unit advances, and the head ejection port is capped. Ink presence detection sequence is 2
Perform for each page record.

<Structure Around the Head> FIG. 3 is a diagram showing the periphery of the recording head and the ink cartridge of the color printer of FIG. The inkjet head 1 discharges ink according to a recording signal. The ink supply pipe 2 is provided in the inkjet head 1 and guides the ink in the ink cartridge 4 from the ink supply hole 3 to the distributor 6. The ink cartridge 4 is a cartridge for black ink, and the ink cartridge 5 is a cartridge for color ink having yellow, magenta, and cyan inks therein.

The recording head 1 has the following configuration. The recording head 1 has a group of nozzles for yellow, magenta, cyan, and black on its front end in a straight line. Each group has 24 nozzles for yellow, magenta, and cyan, and 6 for black.
It has four nozzles, and each of these discharge ports (nozzles) is provided with an ink liquid path communicating with the discharge port, and ink is supplied to these liquid paths behind a portion where the ink liquid path is provided. A common liquid chamber is provided.

In the ink passage corresponding to each of the discharge ports,
An electrothermal converter that generates thermal energy used for discharging ink droplets from these discharge ports and electrode wiring for supplying power to the electrothermal converter are provided. These electrothermal transducers and electrode wires are formed on a substrate made of silicon or the like by a film forming technique. Further, the discharge port, the ink liquid path, and the common liquid chamber are formed by laminating a partition wall, a top plate, and the like made of resin and glass material on the substrate. Further behind, a drive circuit for driving the electrothermal transducer based on a recording signal is provided in the form of a printed circuit board. The silicon board and the printed board are fixed on the same aluminum plate 1a.

The ink cartridges 4 and 5 are inserted substantially in parallel with the aluminum plate 1a, and are connected to an ink supply pipe 2 which also projects in parallel with the aluminum plate 1a.
The ink supply pipe 2 protrudes from a plastic member called a distributor 6 extending in a direction perpendicular to the silicon substrate, and further communicates with a flow path therein, which flow path communicates with a common liquid chamber.

The ink flow paths in the distributor 6 include four ink channels for yellow, magenta, cyan, and black.
There is a book, which communicates each common liquid chamber with the ink supply pipe 2. The ink supply pipes 2 are also divided into three and one ink supply pipes because the ink cartridges are arranged on the left and right with respect to the aluminum plate 1a so as to be divided into 5 for color (for yellow, magenta, and cyan) and 4 for black. Can be

FIG. 4 is a sectional view showing the inside of the black ink cartridge 4. Color ink cartridge 5
The principle is the same. An ink bag 25 exists inside the ink cartridge, and the bag 25 is filled with ink. Further, two negative pressure plates 26 are contained in the bag 25, and a compression negative pressure spring 27 is pressed against the inside of the plate.
A negative pressure is applied to the ink by the load of the spring 27, so that the ink does not fly out of the nozzles even when unexpected vibration occurs. The lower end of the ink bag 25 is adhered to the seal mold 28. A seal rubber 2 is provided at the center of the seal mold 28.
9 is press-fitted. The ink supply hole 3 for inserting the ink supply pipe 20 is opened in the rubber 29, but when the pipe is not inserted, the ink is closed by elasticity, so that ink does not spill.

<Structure of Recording Head> FIG. 5 is a perspective view showing the inside of the head 1 of the printer of this embodiment, and FIG. 6 is a top view thereof. In the figure, a silicon heater board 17 has a nozzle wall 1 formed thereon by a semiconductor process.
8, a liquid chamber wall 19 and a discharge heater (electrothermal converter) 20 are formed. A glass top plate 21 is bonded and fixed on the board 17 to form a nozzle 22 and a common liquid chamber 23. The ink is supplied from the liquid chamber 23 to the nozzle 22 by capillary force. As described in FIG. 3, the nozzle arrangement includes 24 nozzles each for yellow, magenta, and cyan, and 64 nozzles for black. Eight nozzles are equivalent between color nozzles, and between cyan and black. Has an interval equivalent to 16 nozzles. The aluminum sensor 24 is provided at a portion of 16 nozzles between the color nozzle and the black nozzle, and can detect a head temperature by a change in resistance of the sensor portion due to a temperature. As the temperature sensor, a thermocouple or another sensor having appropriate accuracy may be externally mounted on the head substrate.

When ejecting ink, a pulse voltage is applied to the heater 20 arranged at the nozzle to be ejected, and the ink in contact with the heater 20 is heated. The heated ink vaporizes and expands, applying pressure to the ink in the nozzle.
For this reason, the ink is ejected from the nozzle 22 in a liquid state. <Method of Detecting Ink> Next, a method of detecting the presence or absence of ink in the printer of the present embodiment will be described.

When a pulse voltage of a certain width is applied to the heater 20 to eject ink, about 50% of the input energy
Conducts heat on the heater board 17 to raise the temperature of the board,
The remaining 49% is taken away with the ejected ink, and 1% becomes kinetic energy. Therefore, comparing the case where the ink is present in the nozzle and the normal ejection is performed and the case where the ink is not ejected due to the ink exhaustion, the heater when the ink is exhausted is only 49% which should be taken away by the ejected ink. Board 1
The energy given to 7 increases. By utilizing this, the presence or absence of ink can be detected by detecting the heater temperature with the aluminum sensor 24.

In this embodiment, the following detection sequence is performed. FIG. 7 shows a temperature rise curve with time on the horizontal axis, and corresponds to the following description. First, a pulse having a width of 3 μsec for 2500 shots at 5 KHz is applied from all the black nozzles. At this time, no ink is ejected because the pulse width is short. This operation is hereinafter referred to as a non-ejection detection mode. At this time, the temperature rise value detected by the aluminum sensor is defined as Tr.
Here, after an interval of 1 sec, 100 at 5 KHz
A zero pulse of 7 μsec in width is applied. At this time, if there is ink, the ink is ejected. This operation is hereinafter referred to as an ejection detection mode. The solid line in FIG. 7 indicates a curve when ink is present, and the broken line indicates a curve when ink is exhausted. The temperature rise value at this time is defined as Ta. In the case where ink is present, the temperature Ta which rises is lower than in the case where there is no ink, because energy is taken away by the ink to be ejected. Then, after an interval of 1 sec, 1000 pulses of 5 μHz and a width of 7 μsec are applied from all the yellow, magenta and cyan nozzles. The temperature rise value at this time is defined as Tb. here,
Calculate Ra = Ta / Tr and Rb = Tb / Tr. The temperature rise is lower in the presence of ink than in the absence of ink, and the same relationship holds for Ra and Rb.
Next, the respective values are compared with the respective reference values Raf and Rbf, and the determination is made as follows.

If Ra <Raf, there is black ink. If Ra> Raf, there is no black ink. If Rb <Rbf, there is color ink. If Rb> Rbf, there is no color ink. In this embodiment, Ra = Ta / Tr to increase detection accuracy. And Rb = Tb / Tr were compared with reference values to determine the presence or absence of ink. The reason will be described with reference to FIG. The horizontal axis in FIG. 8 indicates the numbers assigned to the twelve heads. As shown in FIG. 8, when the recording heads are different, the thermal characteristics thereof vary, and it is impossible to determine the presence or absence of ink from the temperature rise values Ta and Tb. Therefore, T
measuring the temperature characteristic of the head,
By calculating the ratio of r and Ta or Tr and Tb, variations between heads are corrected. With this method, the presence / absence of ink can be accurately determined regardless of the characteristics of each head.

The reference values Ra and Rb are, for example, as shown in the graph of FIG.
, Ta, Tb and Tr in the absence of ink are experimentally determined, and based on them, Ra and R in the presence of ink are obtained.
b, calculate Ra and Rb when there is no ink. With respect to Ra and Rb thus obtained, Raf and Rbf may be respectively selected as appropriate values intermediate between values when ink is present and values when ink is not present.

<Description of Control Structure> Next, a control structure for executing the recording control of the above-described apparatus will be described with reference to a block diagram shown in FIG. In the figure showing a control circuit, an interface 1700 inputs a recording signal. The MPU 1701 controls the entire printer, and the ROM 1702 stores a control program executed by the MPU 1701. The RAM 1703 stores various data (such as the print signal and print data supplied to the head). The gate array 1704 includes the recording head 17
08, and control of data transfer among the interface 1700, the MPU 1701, and the RAM 1703. A carrier motor 1710 conveys a recording head 1708, and a conveyance motor 1709 conveys recording paper. The head driver 1705 drives the head. Motor drivers 1706 and 1707 drive a transport motor 1709 and a carrier motor 1710, respectively.

The operation of the above control configuration will be described. When a recording signal enters the interface 1700, the gate array 1
The recording signal is converted into recording data for printing between the 704 and the MPU 1701. And the motor driver 1
The printheads 706 and 1707 are driven, and the printhead is driven according to the print data sent to the head driver 1705 to perform printing.

The MPU 1701 executes a program stored in the ROM 1702 to measure the temperatures in the non-discharge mode / discharge mode described above, calculate the rates Ra and Rb from the measured temperatures, and compare them with a reference value. Execute according to. Further, the reference values Raf, Rbf
Is determined experimentally in advance in ROM 1702 or R
AM1703. FIG. 10 is a flowchart showing the procedure of a program stored in the ROM 1702 to execute the above determination. FIG.
The contents of the procedure 0 are the same as those described in the section of <Ink detection method>.

As described above, the ink jet printer of this embodiment measures the temperature of the head in the non-ejection mode and the ejection mode and detects the presence or absence of ink based on the ratio. Ink can be detected without being affected, and a large-scale device is not required, and small, inexpensive, and reliable ink detection is possible. Although the present embodiment relates to a color printer, it can be similarly applied to a monochrome printer. The object to be detected is not limited to ink, but can be detected in the same manner as ink if it is an appropriate liquid.

It should be noted that the present invention brings about an excellent effect particularly in an ink jet recording head and a recording apparatus in which a flying liquid droplet is formed by utilizing thermal energy and recording is performed. For the representative configuration and principle, see, for example, US Pat.
It is preferable to use the basic principle disclosed in Japanese Patent Nos. 23129 and 4740796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). Electrothermal transducers
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer and film boiling occurs on the heat acting surface of the recording head. As a result, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed, which is effective. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubbles are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. When the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface are adopted, excellent recording can be performed. As a configuration of the recording head, in addition to the combination of the ejection port, the liquid path, and the electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, a heat acting surface U.S. Pat. No. 4,558, which discloses an arrangement in which the
333 and U.S. Pat. No. 4,459,600 may be used.

In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, or absorbs pressure waves of thermal energy. A configuration based on JP-A-59-138461, which discloses a configuration in which an opening corresponds to a discharge unit, may also be employed. Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either the configuration or the configuration as one recording head integrally formed may be used.

In addition, it is integrated with a replaceable chip-type recording head that can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being attached to the apparatus main body, or integrated with the recording head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.
It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like, which are provided as components of the printing apparatus of the present invention, since the effects of the present invention can be further stabilized. If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, and printing Performing a preliminary ejection mode for performing another ejection is also effective for performing stable printing.

Further, the printing mode of the printing apparatus is not limited to the printing mode of only the mainstream color such as black, but may be an integrated printing head or a combination of a plurality of printing heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture. In the embodiments of the present invention described above, the ink is described as a liquid.However, an ink that solidifies at room temperature or below and softens at room temperature or is a liquid, or in the above-described inkjet method, Generally, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Anything can be used as long as

In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or solidified in a standing state for the purpose of preventing evaporation of the ink. Either ink may be used, or in any case, the ink may be liquefied by application of heat energy according to the recording signal and ejected as a liquid ink, or may already start to solidify when reaching the recording medium. The use of an ink having a property of being liquefied for the first time by thermal energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, in which the porous sheet is opposed to the electrothermal converter while being held in a liquid or solid state in the concave portions or through holes of the porous sheet. It may be. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the recording apparatus according to the present invention may be combined with a reader or the like in addition to the one provided as an image output terminal of an information processing device such as a word processor or a computer as described above. It may take the form of a copier, or a facsimile machine having a transmission / reception function.

[0043]

Second Embodiment FIG. 11 is a diagram showing the vicinity of a recording head and a tank of an ink jet printer according to a second embodiment. The configuration of the entire apparatus is the same as that of the first embodiment. The ink cartridges are black 4, yellow 30, magenta 31,
There are cyan 32, each of which is interchangeable. In order to determine the presence / absence of ink in each of these ink cartridges, similarly to the first embodiment, after measuring Tr in the non-ejection detection mode, yellow, magenta, and cyan are sequentially ejected at intervals of 0.5 sec after 1 sec has elapsed. Then, each temperature rise value is measured, and each is divided by Tr to obtain four Rs. That is, in the first embodiment, the temperature rise Tb when the voltage is applied to the three colors at once to determine the presence or absence of the ink in the color ink cartridge at once for the three colors.
Is measured, but in this embodiment, it is measured separately for each color. By comparing each of the obtained values of R with the reference value, it is possible to determine the presence or absence of ink in each ink cartridge. In this embodiment, since the number of nozzles for yellow, magenta, and cyan is the same for 24 nozzles, the same value can be used as a reference value for comparison with R. Therefore, in the apparatus of the present embodiment, the presence or absence of ink for each color can be detected, and two reference values, one for color and one for black, are sufficient.

[0044]

Third Embodiment In this embodiment, ink is simultaneously ejected from black and color nozzles in the ejection detection mode. Taking the head of the first embodiment as an example, in the four tanks, if the black tank is empty, 64 heaters are empty, and if one color ink tank is empty, 24 heaters are empty. The heater is empty, and the energy input to the head substrate is different in each case, resulting in a difference in the temperature rise value. Therefore, if the temperature rise value is detected, it can be determined whether the empty tank is black or color, and how many colors are empty. In the case of this embodiment, as shown in FIG.
By having seven types of reference values Rf to R7f, it becomes possible to determine. The table of FIG. 12 shows, from the left, the state of the presence or absence of ink, the value Ri of the ejection mode / non-ejection mode, and the reference value R for determining Ri to associate the Ri with the state of the presence or absence of ink.
f.

As in the first embodiment, the ink discharge mode and the non-discharge mode are measured experimentally in the presence or absence of the eight inks described in the table, and their ratios R1 to R8 are calculated. Since the eight states indicated and displayed have different numbers of heaters that are empty, R1 to R8 are also different from each other,
Reference values R1f to R7f can be selected between the respective values.

A detection sequence for detecting the presence / absence of an ink state will be described with reference to the flowchart of FIG. In step S201, a non-discharge detection mode is performed, and Tr is measured. After waiting for 1 second in step S202, step S202
At 203, the ejection detection mode is performed, and Ta is measured. In step S204, R = Ta / Tr is calculated. Next, in step S205, a magnitude comparison between R and R1f in FIG. 9 is performed. If R <R1f, it is determined that all ink is present, and printing is continued as it is. Conversely, if R> R1f, R2f and R are compared in the next step S206. Here, R1f
If <R <R2f, it is determined that the color cartridge is empty for one color, and that fact is displayed on display means (not shown). Less than,
Similarly, in steps S207 to S211, R and R3f to R7
By comparing f, the presence or absence of ink in the ink cartridge is detected. Finally, it is determined in step S212 that there is no ink.

However, in the above procedure, since the number of nozzles for yellow, magenta, and cyan is the same, it cannot be determined which color ink cartridge is empty. However, when energy is applied to the heater in the non-discharge mode / discharge mode, if the number of target yellow, magenta, and cyan discharge nozzles is changed to, for example, 16, 20, and 24, the rise when each becomes empty is increased. Since the temperature changes, it is possible to determine which color cartridge is empty. At this time, it is sufficient that there are 14 reference Rf. In the method of the present embodiment, the detection time is short, and the amount of ink to be ejected at the time of detection is small, which is economical. Particularly, in a head having a large number of nozzles, the difference between a plurality of reference values can be set large, so that the rate of erroneous detection can be reduced.

[0048]

Fourth Embodiment The non-ejection detection mode of the first embodiment is a measure for correcting variations in the temperature characteristics of the recording head caused by variations in wiring resistance and variations in the thickness of the adhesive layer. If this variation is small, the non-ejection detection mode is unnecessary, and the presence or absence of ink can be detected by comparing the temperature rise during the execution of the ejection detection mode with a reference temperature rise value. This method has the advantage that the detection time is short and the useless pulse is not applied, so that the life of the discharge heater is extended,
There is also an advantage that the number of head replacements can be reduced.

[0049]

Fifth Embodiment If the ink jet printer described in the first embodiment is left for a long time, air is mixed in from the nozzle discharge port or the path from the tank to the recording head, and bubbles are generated in the ink. Due to these bubbles, ink ejection failure occurs. Conventionally, to prevent this, a so-called recovery measure has been taken in which a timer is provided inside the apparatus and ink is automatically discharged from a discharge port by using a pump at predetermined time intervals. The discharge amount at this time is set to an amount sufficient to remove bubbles. However, the amount of air bubbles varies depending on the environment in which the apparatus is placed, and the air bubbles cannot be removed by this discharging operation, resulting in defective discharge. Therefore, in the present embodiment, after the discharging operation, the detection sequence described in the first embodiment is performed to determine whether or not bubbles exist in the nozzle. In this embodiment, an ink suction purge unit as shown in FIG. 14 is used. In the figure, the purge unit 41 has hollow portions for black and color inside. A cap rubber 42 is provided on the front surface of the unit 41, and a state in which the orifice surface of the head 1 is pressed against the rubber 42 can be sucked. The rubber 42 is provided with a color slit 43 and a black slit 44. Air suction tube 45 in the cavity,
46 is connected to the suction pump 4 via the switching valve 47.
Connect to 8. Whether to suction color and black simultaneously or only color or black alone can be selected by a valve 47. The sucked ink is discarded from a discharge ink tube 49, 50 having an ink supply member (not shown) therein to a waste ink tank (not shown).

FIG. 15 is a flowchart showing a control procedure of the head recovery operation by the MPU 1701. FIG.
The recovery operation will be described based on FIG. First, step S30
In step 1, ink is sucked from a discharge port by a pump. This is a process conventionally performed. Step S302
In the same manner as in the first embodiment, Tr is measured in the non-ejection mode, and after waiting one second in step S303, Ta is measured in the black ejection mode in step S304. Step S3
At 05, Ra is calculated by dividing Ta by Tr. next,
In step S306, Tb is measured in the color discharge mode, and in step S307, Tb is divided by Tr to calculate Rb.

In step S308, Ra is compared with the reference value Raf. If Ra <Raf, it is determined that there are no bubbles, and the process proceeds to step S310. If Ra> Raf, there is a bubble, and in step S309, the switching valve 47 is switched to change only the black ink. Suction. Thereafter, the process returns to step S304, and repeats steps S304 to S308. At this time, if there is a bubble, Ra or Rb becomes larger than the reference value, so that the discharging operation is performed again. Thereafter, detection and discharge are repeated until it is determined that there is ink.

If Ra <Raf when the bubbles are removed, the process proceeds to step S310, and the same sequence as that for black is repeated for color. At that time, the switching valve is set so as to suck only the color ink. Step S31
If it is determined at 0 that Rb <Rbf, the recovery operation ends. If Ra <Raf or Rb <Rbf is not determined even if suction is repeated five times, it is determined that there is no ink, and an out-of-ink display is performed.

When the above-described recovery sequence is performed, the presence or absence of ink is detected and bubbles are sucked, so that bubbles are reliably removed and a printer with high ejection reliability can be realized. In addition, the above-described method can be applied when replacing the ink cartridge. The present invention may be applied to a system including a plurality of devices or to an apparatus including a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

[0054]

As described above, the recording apparatus and the ink detecting method according to the present invention have an effect that the presence or absence of ink can be detected simply and reliably without using any special parts.

[Brief description of the drawings]

FIG. 1 is a perspective view of a printer according to an embodiment.

FIG. 2 is a cross-sectional view of a conventional ink detecting member.

FIG. 3 is a diagram illustrating the vicinity of a recording head and a tank of the printer according to the embodiment.

FIG. 4 is a sectional view of the ink cartridge.

FIG. 5 is an exploded perspective view of a head.

FIG. 6 is a top view of the head.

FIG. 7 is a temperature curve at the time of ink detection.

FIG. 8 is a diagram illustrating a variation in temperature between heads when ink is detected.

FIG. 9 is a block diagram of a control configuration of the printer according to the embodiment.

FIG. 10 is a flowchart illustrating a procedure of ink detection of the printer of the first embodiment.

FIG. 11 is a diagram illustrating the vicinity of a head and a tank of a printer according to a second embodiment.

FIG. 12 is a table showing criteria for ink detection of the printer of the third embodiment.

FIG. 13 is a flowchart illustrating a procedure of ink detection of the printer of the third embodiment.

FIG. 14 is a perspective view of a purge unit according to a fifth embodiment.

FIG. 15 is a flowchart illustrating a procedure of a head recovery operation of the printer according to the fifth embodiment.

[Explanation of symbols]

 1 head, 4,5 ink cartridge, 6 recording paper, 7 carriage, 13 purge unit, 17 heater board, 20 heater, 22 nozzle, 24 aluminum temperature sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/175 B41J 29/46

Claims (7)

(57) [Claims] Claims: 1. By applying thermal energy to an ink ,
A recording apparatus that performs recording using a recording head that discharges the ink , wherein a predetermined amount of ink is not discharged from the recording head.
The recording head when heat energy is applied to the ink
Value Tr corresponding to the amount of temperature change of the recording head
A predetermined amount of thermal energy enough to eject ink from the
The amount of temperature change of the recording head when applied to ink
Detecting means for detecting a corresponding information value T; and a ratio T of the Tr and T detected by the detecting means.
/ Tr and a predetermined reference value Raf.
To determine whether the recording head has a sufficient amount of ink.
Determining means for determining whether or not ink is ejected from a predetermined recording head.
To the prescribed recording when the thermal energy of
The information value Tr ′ corresponding to the temperature change amount of the
A predetermined heat energy that is sufficient to eject ink from the recording head
The predetermined recording head when energy is applied to the ink.
Information value corresponding to the temperature change amount of the
Corresponding to the temperature change when ink is present in the recording head
The ratio between the information value Ta and the information value Ta is defined as Ta / Tr ′.
A predetermined amount of ink that is ejected from the specified printhead
The above-mentioned predetermined description when heat energy of
Information value corresponding to the temperature change amount of the recording head,
The amount of temperature change when there is no ink in the fixed printhead
When the ratio with the corresponding information value Ta 'is Ta' / Tr ',
The reference value Raf is defined as Ta / Tr ′ <the reference value R
af <the value defined as Ta ′ / Tr ′, and the determination unit determines that T / Tr <the reference value Raf.
When it is determined that there is ink, there is not enough ink in the recording head.
The reference value Raf <the T / Tr.
When it is determined that there is ink, there is not enough ink in the recording head.
A recording apparatus characterized in that it is determined that there is no quantity . 2. The method according to claim 1 , wherein the thermal energy is applied to the ink.
Perform recording using a recording head that discharges the ink.
A recording apparatus, wherein a predetermined amount of ink is not discharged from the recording head.
The recording head when heat energy is applied to the ink
The first information value corresponding to the temperature change amount of the
Heat energy enough to eject ink from the pad
Temperature change amount of the recording head when ink is applied to the ink
Detecting means for detecting a second information value corresponding to the first information value and the first information value detected by the detecting means.
Based on the second information value and a predetermined reference value,
To determine if there is sufficient ink in the recording head
And a judging means, wherein the recording head has a plurality of liquid paths, it is supplied to the liquid passage in which a plurality of types of inks corresponds to each ink, said detecting means, respectively corresponding to the plural types of ink temperature of grant to the printhead energy for each liquid path for
A recording apparatus, wherein an information value corresponding to a change amount is detected, and the determination unit determines whether or not there is a sufficient amount of ink for each of the liquid paths corresponding to the plurality of types of ink. 3. A method of applying thermal energy to ink.
Perform recording using a recording head that discharges the ink.
A recording apparatus, wherein a predetermined amount of ink is not discharged from the recording head.
The recording head when heat energy is applied to the ink
The first information value corresponding to the temperature change amount of the
Heat energy enough to eject ink from the pad
Temperature change amount of the recording head when ink is applied to the ink
Detecting means for detecting a second information value corresponding to the first information value and the first information value detected by the detecting means.
Based on the second information value and a predetermined reference value,
To determine if there is sufficient ink in the recording head
And a judging means, wherein the recording head has a plurality of liquid paths, are supplied to the liquid passage in which a plurality of types of inks corresponds to each ink, said determining means, corresponding to said plurality of types of ink There are a plurality of reference values according to the number of fluid paths, and the reference value and the first
Ink is sufficient based on the information value and the second information value
A recording apparatus for determining whether or not there is an amount . 4. An ink jet printer according to claim 1, further comprising a suction unit for sucking ink from said recording head, detecting whether there is a sufficient amount of ink in said recording head after sucking ink by said suction unit,
2. The recording apparatus according to claim 1, wherein suction by said suction means is repeated according to a detection result. 5. The method according to claim 1 , wherein the thermal energy is applied to the ink.
Detecting the ink in the recording head for discharging the ink.
That an ink detection method, the degree of a predetermined said ink is not ejected from the recording head
The recording head when heat energy is applied to the ink
Value Tr corresponding to the amount of temperature change of the recording head
A predetermined amount of thermal energy enough to eject ink from the
The amount of temperature change of the recording head when applied to ink
A detecting step for detecting a corresponding information value T; and a ratio of the Tr and the T detected in the detecting step.
T / Tr is compared with a predetermined reference value Raf
This makes it possible to check whether there is a sufficient amount of ink in the recording head.
And a determination step for determining whether or not ink is ejected from a predetermined recording head.
To the prescribed recording when the thermal energy of
The information value Tr ′ corresponding to the temperature change amount of the
A predetermined heat energy that is sufficient to eject ink from the recording head
The predetermined recording head when energy is applied to the ink.
Information value corresponding to the temperature change amount of the
Corresponding to the temperature change when ink is present in the recording head
The ratio between the information value Ta and the information value Ta is defined as Ta / Tr ′.
A predetermined amount of ink that is ejected from the specified print head
The above-mentioned predetermined description when heat energy of
Information value corresponding to the temperature change amount of the recording head,
The amount of temperature change when there is no ink in the fixed printhead
When the ratio with the corresponding information value Ta 'is Ta' / Tr ',
The reference value Raf is defined as Ta / Tr ′ <the reference value R
af <the value defined as Ta ′ / Tr ′, and the determination unit determines that T / Tr <the reference value Raf.
When it is determined that there is ink, there is not enough ink in the recording head.
The reference value Raf <the T / Tr.
When it is determined that there is ink, there is not enough ink in the recording head.
Ink detection method characterized in that it is determined that there is no quantity
Law. 6. The method according to claim 6 , wherein thermal energy is applied to the ink.
Detecting the ink in the recording head for discharging the ink.
That an ink detection method, the degree of a predetermined said ink is not ejected from the recording head
The recording head when heat energy is applied to the ink
The first information value corresponding to the temperature change amount of the
Heat energy enough to eject ink from the pad
Temperature change amount of the recording head when ink is applied to the ink
A detecting step for detecting a second information value corresponding to the first information value and the first information value detected in the detecting step.
And the second information value and a predetermined reference value.
To determine whether there is a sufficient amount of ink in the printhead
The recording head has a plurality of liquid paths and a plurality of types of inks.
Are supplied to the corresponding liquid paths for each ink, and in the detecting step, each of the plurality of types of inks is
Energy is applied to each of the corresponding liquid paths to
Detecting an information value corresponding to the degree of change of the ink, and in the determining step, each of the plurality of types of ink is
Determine if there is enough ink for each corresponding fluid path
An ink detection method, characterized in that: 7. A method of applying thermal energy to ink,
Detecting the ink in the recording head for discharging the ink.
That an ink detection method, the degree of a predetermined said ink is not ejected from the recording head
The recording head when heat energy is applied to the ink
The first information value corresponding to the temperature change amount of the
Heat energy enough to eject ink from the pad
Temperature change amount of the recording head when ink is applied to the ink
A detecting step for detecting a second information value corresponding to the first information value and the first information value detected in the detecting step.
And the second information value and a predetermined reference value.
To determine whether there is a sufficient amount of ink in the printhead
The recording head has a plurality of liquid paths and a plurality of types of inks.
Are supplied to the liquid paths corresponding to each ink, and a plurality of liquid paths are provided in accordance with the number of liquid paths corresponding to the plurality of types of ink.
The reference value, and in the determining step, the reference value and the second
Based on the first information value and the second information value,
Ink detection characterized by determining whether there is a quantity
Method.