JPH04286653A - inkjet recording device - Google Patents

Abstract

PURPOSE:To provide an ink jet recording apparatus constituted so that the cause of trouble can be discovered at an early stage by easily and certainly detecting the disconnection of an ink sensor (ink detection means). CONSTITUTION:In an ink jet recording apparatus, an ink sensor detecting the presence of ink by the detection of negative pressure is provided in the ink supply passage connecting a recording head emitting ink and a freely replaceable ink cartridge supplying ink and a disconnection detection means detecting the disconnection of the ink sensor from the output of a cartridge sensor (cartridge detection means) detecting whether or not the ink cartridge is mounted and the output of the ink sensor is mounted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording apparatus that records information by ejecting ink onto a recording medium, and more particularly to a disconnection detection technique for an ink detection means for detecting the presence or absence of supplied ink.

0002

2. Description of the Related Art An ink jet recording apparatus is composed of an ink tank and a recording head that discharges ink droplets. Ink tanks are generally provided in a cartridge type in order to facilitate replacement. Since the recording head may be destroyed if it is driven without ink, it is necessary to detect whether ink remains in the ink cartridge.

0003

[Problems to be Solved by the Invention] Conventionally, means for detecting the presence or absence of ink in an ink cartridge include a mechanical switch, a sensor that measures the resistance value of the ink, and a sensor that detects the negative pressure of the ink. etc.

[0004] When a sensor or a switch is used to detect ink, there is a possibility that the sensor or the like may be disconnected, regardless of the method used, and it is necessary to detect this disconnection by some method. However, the conventional device does not provide an effective means for detecting such a disconnection.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide an inkjet recording apparatus that can easily and reliably detect a disconnection of an ink detection means (ink sensor).

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a recording head that records information by ejecting ink onto a recording medium, and an ink for supplying ink to the recording head. a supply path; an ink cartridge with a built-in ink tank that is removably attached to the ink supply path and supplies ink to the recording head through the ink supply path; and whether or not ink is supplied to the ink supply path. an ink detection means for detecting whether the ink cartridge is attached to the ink supply channel by detecting negative pressure in the ink supply path; a cartridge detection means for detecting whether or not the ink cartridge is attached to the ink supply channel; and a detection output of the ink detection means and the cartridge. The present invention is characterized by comprising a wire breakage detection means for detecting a wire breakage of the ink detection means based on the detection output of the detection means.

[0007] Another aspect of the present invention is characterized in that it includes a warning means for displaying or audibly outputting a warning to the user that a wire is broken in response to the wire breakage being detected by the wire breakage detecting means.

In another aspect of the present invention, the ink detection means is a pressure sensor that outputs a detection signal indicating that ink is being supplied even when the ink cartridge is not mounted. .

In another aspect of the present invention, the disconnection detection means detects when the detection signal from the cartridge detection means indicates that the ink cartridge is absent and the detection signal from the pressure sensor indicates that there is no ink supply. The method is characterized in that it is determined that the pressure sensor is disconnected.

In another aspect of the present invention, the recording head includes an electrothermal transducer for applying thermal energy to cause film boiling on the ink, as an element that generates energy for ejecting the ink. It is characterized by having the following.

[0011]

[Operation] In the present invention, a detection type that detects the presence or absence of ink by detecting negative pressure is used as the ink detection means, and a detection signal from the ink detection means and a detection signal indicating the presence or absence of an ink cartridge from the cartridge detection means are used. The presence or absence of a disconnection in the ink detection means is detected based on both of the above. This ink detection means uses the generation of negative pressure when the recording head absorbs ink to detect the presence or absence of ink supply, so if no ink cartridge is installed, such negative pressure will not occur, so the ink Even if there is no supply of ink from the ink tank, the same status signal as if there is ink will be output. However, if a disconnection occurs in the ink detection means at such a time, a signal indicating the absence of ink will be input to the disconnection detection means, so it can be easily determined whether or not there is a disconnection state.

On the other hand, ink detection means using other detection methods such as ink resistance value detection or mechanical switches output a detection signal indicating that there is no ink when an ink cartridge is not installed. Become. Therefore, even if a disconnection occurs in the ink detection means at this time, the output level of the detection signal indicating the absence of ink does not change, and therefore such a disconnection cannot be detected. Thus, it can be seen that the above effects of the present invention can be obtained by using the ink detection means based on negative pressure detection.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the basic configuration of an ink jet recording apparatus according to an embodiment of the present invention. In the figure, A is a recording head that records information by ejecting ink onto a recording medium. B is an ink supply path for supplying ink to the recording head A. C is an ink cartridge with a built-in ink tank that is detachably attached to the ink supply path B and supplies ink to the recording head A through the ink supply path B. Reference numeral D denotes an ink detection means for detecting whether or not ink is supplied into the ink supply path B by detecting negative pressure within the ink supply path B. Reference numeral E denotes a cartridge detection means for detecting whether or not the ink cartridge C is attached to the ink supply path B. F is a disconnection detection means for detecting a disconnection of the ink detection means D based on the detection output of the ink detection means D and the detection output of the cartridge detection means E.

Further, G is a warning means for displaying or audibly outputting a warning to the user that a wire is broken in response to the wire breakage being detected by the wire breakage detecting means F.

As a preferred example, the ink detection means D is a pressure sensor that outputs a detection signal indicating a state in which ink is being supplied even when the ink cartridge C is not mounted. Further, as a preferred example, the disconnection detection means F detects the disconnection of the pressure sensor D when the detection signal from the cartridge detection means E indicates that there is no ink cartridge and the detection signal from the pressure sensor D indicates that there is no ink supply. It is determined that there is.

FIG. 2 shows, as a preferred embodiment of the present invention,
1 shows the configuration of a color inkjet recording apparatus that generates ejection energy using an electrothermal converter. In the figure, a recording medium 1 such as paper or a plastic sheet is placed above and below a recording area and is supported by a pair of conveyance rollers 2 and 3, and is moved by the conveyance roller 2 driven by a sheet feed motor 4 at an arrow mark in the figure. direction (main scanning). A guide shaft 5 is provided in front of and parallel to the conveyance rollers 2 and 3. The carriage 6 is reciprocated along this guide shaft in the direction of arrow B (sub-main scanning direction) in the figure by the output of a carriage motor 7 via a wire 8.

The carriage 6 as a head moving means is an inkjet recording device having an electrothermal transducer therein for applying thermal energy to cause film boiling on the ink as an element for generating energy for ejecting the ink. A head unit 90 is mounted. This recording head unit 90 is for color images, is arranged in the operating direction of the carriage, and is configured to correspond to each color ink of cyan (C), magenta (M), yellow (Y), and black (Bk). The four recording heads 9 provided are a black head 9A, a cyan head 9B, and a magenta head 9C.
, yellow head 9D. Each recording head 9
A plurality of (for example, four
An ink ejection unit is provided in which 8 or 64 ink ejection ports are arranged in a vertical line in a direction intersecting the operating direction of the carriage.

FIG. 3 shows the recording heads 9 (recording heads 9A to 9A).
9D) schematically shows a longitudinal cross-sectional structure of a part of the ink ejection part.

In the figure, a plurality of ink ejection ports 10 are formed at a predetermined pitch in the vertical direction on the surface facing the recording medium 1, and a plurality of ink ejection ports 10 are provided corresponding to each ink ejection port 10 based on recording information. Driving (heating with electricity) an electrothermal converter (heating resistor, etc.) 11 to cause a film boiling phenomenon in the ink,
A bubble 11A is generated, and the pressure at this time causes ink to be ejected to form flying ink droplets 12, and the ink droplets are deposited in a predetermined pattern on the recording medium 1, thereby creating a character image, etc. in a dot pattern. information is recorded.

Each recording head 9 is provided with a heat driver 13 for turning on and off electricity to the electrothermal transducer, and a circuit board of a drive circuit (driver) 29 for performing the above-mentioned driving is mounted on the carriage 6. It is provided. 10A is a liquid path, and 10B is a common liquid chamber.

The control unit including the engine control circuit (CPU) of the recording apparatus and the ROM, RAM, etc. attached thereto receives command signals and data signals (
Based on these signals, power is applied to drive sources such as various motors, etc., and the electrothermal transducers of each recording head 9A to 9D are driven via the head drive circuit 29 and heat driver 13. Power supply (heat power supply)
Apply and energize.

The operation panel 160 of FIG. 2 attached to the exterior case (not shown) of the recording device includes an online/offline switching key 16A, a line field key 16B,
Form feed key 16C, recording mode switching key 16
In addition to key setting sections such as D, multiple alarm lamps 16E
A display section including warning lamps such as a power lamp 16F and a power lamp 16F is provided.

FIG. 4 shows the configuration of the control system of the color ink jet recording apparatus shown in FIG. In FIG. 4, a CPU 21 in the form of a microprocessor is connected to a host machine 14 via an interface 22, and receives instruction signals (commands) and recorded information signals read into a data memory 23 from a controller of the host machine 14, as well as a ROM. The recording operation is controlled based on a program as shown in FIG. 6 stored in the program memory 24 in the form of a RAM, and recording command data stored in the working memory 25 in the form of a RAM. That is, the CPU 21 controls the carriage motor 7 and the sheet feed motor 4 via the output port 26 and the motor driver 27, and also controls the recording head via the head control circuit 29 based on the recording information stored in the data memory 23. 9 to perform recording. The output from each operation key 16A to 16D (FIG. 2) on the operation panel 160 is transmitted to the CPU 21 via the input port 32, and the output from the CPU 21 is transmitted to the warning lamps 16 such as the alarm lamp 16E and the power lamp 16F. A control signal is provided from the output port 36. Also, reference number 3
3 is a DIP switch provided on the bottom of the exterior of the device, and its output is connected to the CP via the input port 34.
It is transmitted to U21.

Further, from the power supply circuit 28, a logic drive voltage VCC (for example, 5V) for operating the control logic circuit, various motor drive voltages VM (for example, 30V),
A reset voltage RESET, a heat voltage VH (for example, 25 V) for energizing the electrothermal transducer 11 of the recording head 9 to generate heat, and a backup voltage VDDH for protecting the recording head 9 are output, respectively. Its heat voltage VH
is applied to the recording head 9, and the backup voltage VDDH is applied to the head control circuit 29 and the recording head, respectively.

In the embodiment of the present invention, the ink cartridge 1
a cartridge sensor 42 that detects whether or not 5 is attached;
An ink sensor 41 that detects the presence or absence of ink supply is connected to the CPU 21 via input ports 20 and 43.

FIG. 5 shows an example of an ink cartridge 15 containing ink of a recording apparatus to which the present invention is applied, and an ink sensor 41 that detects the presence or absence of ink. In this embodiment, an ink cartridge 15, an ink sensor 41, and a cartridge sensor 42 for detecting the presence or absence of the ink cartridge 15 are provided as shown in FIG. It also detects whether the cartridge 15 is inserted. Here, 44 is a flexible ink bag surrounded by a housing made of resin, and constitutes the ink cartridge 15. 45
51 is an ink needle that is inserted into the sealing elastic body of the ink cartridge 15 and communicates with the ink sensor 41 of the cartridge 15, and 51 is an ink tube that communicates the ink sensor 41 with the recording head 9. 46 and 47 are contacts of the ink sensor 41, and 48 is a spring that urges the float 50 downward. The float 50 moves up and down integrally with the movable contact 47 and the flexible membrane. 49 is a spring holder.

The ink is sucked by the capillary force of the recording head 9 from the ink bag 44, passes through the sealing elastic body and the ink needle 45, passes through the liquid chamber of the ink sensor 41, and exits to the ink tube 51 side. At this time, if the amount of ink is sufficient for recording, the float 5 is caused by the outflow pressure of the ink.
0 and bring the movable contact 47 of the ink sensor into contact with the fixed contact 46, thereby causing a high (high) indicating that ink is present.
A high) level signal is output to the circuit connected to contacts 47 and 46. When the amount of ink becomes less than a predetermined amount, that is, when there is no more ink in the ink bag 44, the pressure inside the liquid chamber of the ink sensor 41 decreases, and the float 50 moves toward the spring 4.
8, and opens the contacts 47 and 46 of the ink sensor 41, thereby opening these contacts 47 and 4.
Low indicating no ink in the circuit connected to 6
A level signal is output, and the CPU 21 detects the amount of ink.

On the other hand, when the ink cartridge 15 is not installed, the contacts of the cartridge sensor 42 are open and a low level signal is output to the CPU 21, so that the recording head 9 does not eject ink. Therefore, the pressure inside the liquid chamber of the ink sensor 41 at this time is not affected by the suction pressure (negative pressure) caused by capillary force, and therefore does not decrease even if there is no ink supply from the ink cartridge 15. Therefore, the float 50 remains in the upper position, and the ink sensor 41 sends a high level signal indicating the presence of ink to the CPU 21. Therefore, the CPU
21 determines that there is no ink cartridge if the output of the cartridge sensor 42 is low level and the output of the ink sensor 41 is high level. On the other hand, the fact that the output of the ink sensor 41 is at a low level even though the output of the cartridge sensor 42 is at a low level means that there is a disconnection inside the ink sensor 41 or a disconnection in the signal line between the ink sensor 41 and the CPU 21. I can't think of anything else. For this reason, the CPU 21
When both outputs are at a low level, it is determined that the ink sensor is disconnected.

In this embodiment, the warning lamp (alarm lamp) 16E on the panel 160 is used as a warning means, but the present invention is not limited to this, and the warning means is not limited to this, but may include message display on the liquid crystal display screen, generation of a buzzer sound, or message voice using synthesized voice. It may be an output or the like.

FIG. 6 shows a control operation procedure for ink detection, cartridge detection, and wire breakage detection in an inkjet recording apparatus according to an embodiment of the present invention.

First, the above-mentioned inkjet recording apparatus is scanned by the carriage 6, and every time one line is recorded, a signal outputted to the circuit connected to the contacts 46 and 47 goes high.
Whether there is a predetermined amount of ink is detected based on whether the ink level is gh level or low level.

[0033] Explaining according to this flowchart, first, it is detected whether or not the ink cartridge 15 is inserted into the apparatus (S1). When the ink cartridge 15 is inserted, the cartridge detection signal is High.
level, so I go to check the output of the negative pressure ink sensor 41 (S2). Since the output value of the ink sensor 41 becomes High level if there is ink, it is determined to be normal at that time (S3) and the process returns to the original recording routine (main routine). If there is no ink, the level will be low, so in that case, it is determined that there is no ink, the carriage is returned to the home position (S4), and the warning lamp 16E of the panel 160 displays an indication that there is no ink (S5). After this, this routine does not exit until the cartridge 15 is actually replaced. It is determined whether the cartridge 15 has been replaced (S6)
This is done by detecting that the cartridge sensor 42 changes from a low level to a high level.

When the cartridge sensor 42 is at a low level, the output value of the ink sensor 41 is checked in the same way as described above (S7).
5 is not attached, the carriage 6 is moved to the home position (S8), and the warning lamp 16E on the panel 160 displays the absence of a cartridge (S9).
. Thereafter, this routine does not exit until the cartridge 15 is actually installed (S6).

On the other hand, when the output value of the cartridge sensor 42 is at a low level (S1) and the output value of the ink sensor 41 is at a low level (S7), the negative pressure used in this embodiment is used as described above. This is not possible with the ink sensor 41, and in that case, the ink sensor 4
It can be said that this is the 1st disconnection. Therefore, when this is detected (
S10), an error indicating that the ink sensor is disconnected is displayed on the warning lamp 16E of 160 on the panel (S11), and after lowering the motor drive voltage VM and head heat voltage VH (S13), the system is stopped. With the above control means, disconnection of the ink sensor 41 can be detected accurately and easily.

Although a CPU is used as the disconnection detection means in this embodiment, it is of course possible to implement it using a logic circuit.

(Others) The present invention particularly relates to means for generating thermal energy as energy used to eject ink, in an inkjet recording system.
For example, the present invention provides an excellent effect in a recording head or recording apparatus that is equipped with an electrothermal converter (for example, an electrothermal converter, a laser beam, etc.) and uses the thermal energy to cause a change in the state of the ink. This is because such a system can achieve higher recording density and higher definition.

For its typical configuration and principles, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It is applicable to both continuous types, but in particular, in the case of on-demand type, it is applicable to the electrothermal converter placed corresponding to the sheet holding the liquid (ink) or the liquid path. , by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to produce film boiling on the thermally active surface of the recording head. liquid (ink) that corresponds one-to-one to this drive signal.
This is effective because it can form air bubbles inside. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in US Pat. No. 4,463,359 and US Pat.
345262 are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

In addition to the configuration of the recording head that is a combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44 disclose a configuration in which a heat acting part is arranged in a bending region.
A configuration using the specification of No. 59600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

In addition, even in the case of a serial type as in the above example, the recording head is fixed to the apparatus main body or is attached to the apparatus main body, so that electrical connection with the apparatus main body and ink flow from the apparatus main body can be achieved. The present invention is also effective when using a replaceable chip-type recording head that can be supplied with ink or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, etc. to the configuration of the recording apparatus of the present invention, since this further stabilizes the effects of the present invention. Specifically, these include heating the recording head using a capping means, a cleaning means, a pressure or suction means, an electrothermal transducer, a separate heating element, or a combination thereof. For example, there may be mentioned a pre-heating means for performing the ejection, and a pre-ejection means for ejecting other than recording.

Regarding the type and number of recording heads to be mounted, for example, in addition to a single head that corresponds to a single color ink, there are also systems that correspond to a plurality of inks of different recording colors and densities. A plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, Alternatively, the present invention is extremely effective for an apparatus equipped with at least one of the full-color recording modes using color mixing.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or lower, and that softens or liquefies at room temperature, may also be used. Generally speaking, in inkjet systems, the temperature of the ink itself is adjusted within the range of 30°C or higher and 70°C or lower to keep the viscosity of the ink within a stable ejection range. Sometimes, ink in liquid form may be used. In addition, in order to actively prevent temperature rise due to thermal energy by using the energy to change the state of the ink from a solid state to a liquid state, or to prevent ink from evaporating, it is possible to solidify and heat the ink when left standing. An ink that is liquefied by water may also be used. In any case, by applying thermal energy in accordance with the recording signal, the ink is liquefied and the liquid ink is ejected, or the ink has already begun to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied for the first time. Ink in such cases is disclosed in Japanese Patent Application Laid-open No. 54-56847 or Japanese Patent Application Laid-open No. 60-71.
In a state where it is held as a liquid or solid in the porous sheet recesses or through holes, as described in Japanese Patent No. 260,
It may also be configured to face the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the inkjet recording apparatus of the present invention can be used as an image output terminal for information processing equipment such as a computer, a copying machine combined with a reader, or a facsimile machine having a transmitting/receiving function. It may also take a form.

[0046]

[Effects of the Invention] As explained above, according to the present invention,
Since the cartridge detection means for detecting the presence or absence of an ink cartridge and the detection signal from the ink detection means using negative pressure are used, disconnection of the ink detection means can be reliably detected and the cause of failure can be discovered early. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing the configuration of main parts of a color inkjet recording apparatus to which the present invention is applicable.

FIG. 3 is a schematic cross-sectional view illustrating a recording method using an inkjet recording head to which the present invention is applicable.

FIG. 4 is a block diagram showing a circuit configuration of a control system of a color inkjet recording apparatus according to an embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing an example of the configuration of an ink sensor using negative pressure used in an embodiment of the present invention.

FIG. 6 is a flowchart showing a control operation procedure of an ink amount detection control routine of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 Recording medium 2, 3 Conveyance feed roller 4 Sheet feed motor 5 Guide shaft 6 Carriage 7 Carriage motor 8 Wire 9 Recording head 9A Cyan recording head 9B Magenta recording head 9C Yellow recording head 9D Black recording head 10 Ink discharge port 10A liquid path 10B Common liquid chamber 11 Electrothermal converter 11A Bubble 12 Flying ink droplets 13 Heat driver 14 Host machine 15 Ink cartridge 16A-16B Operation keys 16E Alarm lamp 16F power lamp 17 Control board 20 CPU 22 Interface 24 Program memory 27 Motor driver 28 Power supply circuit 29 Head drive circuit 41 Ink sensor 42 Cartridge sensor 44 Ink bag 45 Ink needle 46, 47 Ink sensor contact 48 Spring 49 Spring holder 50 float 51 Ink tube 90 Recording head unit 160 Operation panel

Claims (5)

[Claims] 1. A recording head that records information by ejecting ink onto a recording medium, an ink supply path for supplying ink to the recording head, and a recording head that is removably attached to the ink supply path. an ink cartridge with a built-in ink tank that supplies ink to the recording head through the ink supply path, and detecting whether or not ink is being supplied to the ink supply path by detecting negative pressure in the ink supply path. an ink detection means; a cartridge detection means for detecting whether or not the ink cartridge is attached to the ink supply path; An inkjet recording apparatus comprising a wire breakage detection means for detecting a wire breakage. 2. The apparatus according to claim 1, further comprising a warning means for displaying or audibly outputting a warning to the user that the wire is broken in response to the wire breakage detected by the wire breakage detecting means.
The inkjet recording device described in . 3. The ink detection means is a pressure sensor that outputs a detection signal indicating that ink is being supplied when the ink cartridge is not mounted. Inkjet recording device. 4. The disconnection detection means detects when the pressure sensor is disconnected when a detection signal from the cartridge detection means indicates that the ink cartridge is absent and a detection signal from the pressure sensor indicates that there is no ink supply. 4. The inkjet recording apparatus according to claim 3, wherein the inkjet recording apparatus determines that the inkjet recording apparatus is 5. The recording head includes an electrothermal transducer for applying thermal energy to cause film boiling on the ink, as an element that generates energy for ejecting the ink. The inkjet recording device according to any one of items 1 to 4.