JPH03284953A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To detect whether a cartridge-type ink jet head is provided and also how much ink remains unused by connecting a resistor for detection to be mounted on the head with a specified resistance value to a residual ink detection element in parallel and detecting a resistance value in an ink tank using the element. CONSTITUTION:An ink discharge control element 13 is driven by a drive signal lfrom a printing control part to allow ink discharge from each head nozzle. In addition, two residual ink detection electrodes 15a, 15b are embedded at an appropriate interval in an ink sponge 14 for detection of the resistance value of ink. The resistance value of ink in the sponge 14 to be detected by electrode for residual ink amount detection 15a, 15b varies according to the amount of ink impregnation in the sponge 14, that is, the residual ink amount. Therefore, the residual ink amount in the sponge 14 can be determined by detection of the resistance value. Further, a resistor for detection of the mounting of an ink jet head with a specified resistance value is provided for connection to electrodes for residual ink detection 15a, 15b.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an inkjet recording device.

[Prior Art] Some inkjet recording devices that use a cartridge-type head that integrates an ink tank and an inkjet recording head detect the amount of ink remaining in the ink tank, but it is difficult to install the cartridge-type head. Detection of the presence or absence of a cartridge type head was not often performed, and in some cases, the cartridge type head was operated without being attached. Conventionally, in order to detect whether a cartridge-type head is installed, a voltage that does not eject ink is applied to the head, and the presence or absence of current flowing at that time is detected, or whether a cartridge-type head is installed or not. Accordingly, change the current to 0N10FF
There are some that have a separate switch to do so.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, when checking whether a cartridge-type head is attached, if the inkjet recording head uses a piezo pendulum to eject ink, the piezo pendulum It is difficult to detect the current flowing through the device, and the detection circuit for detection becomes complicated. Also, depending on whether a cartridge type head is installed or not, the switch can be set to 0.
Even when N10FF is used, there are problems such as the need for a dedicated detection circuit.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and an object of the present invention is to provide an inkjet recording device that can easily determine whether a cartridge type head is attached or not, without providing a dedicated detection means. do.

[Means for Solving the Problems] The present invention provides an inkjet recording device that can be attached to and detached from an inkjet recording device in which an ink tank, an ink remaining amount detection element that detects the amount of ink remaining in the ink tank, and an inkjet recording head are integrated. In an inkjet recording apparatus that is equipped with a freely adjustable cartridge-type head and has a remaining ink amount detection means that detects the remaining amount of ink using detection information from the remaining ink amount detection element, the remaining ink amount detection element is located in the ink tank. The cartridge-type head further includes a head attachment detection resistor having a predetermined resistance value connected in parallel to the remaining ink amount detection element, and the remaining ink amount detection means is for detecting ink resistance. , detecting the remaining amount of ink in the ink tank and whether or not the cartridge-type head is attached using detection information corresponding to a resistance value detected by the remaining ink amount detection element; The means includes a power supply circuit that applies a constant current to the remaining ink amount detection element, and a voltage generated in the remaining ink amount detection element by the constant current, which is set in advance.
It has a comparison means for comparing the amount of ink remaining in the ink tank with a reference voltage value indicating the attachment of the cartridge type head.

In addition, the inkjet recording head may be a full-line type having a plurality of ink ejection ports over the entire recording width of the recording medium, or may be an inkjet recording head that uses thermal energy to ink. There are some that are equipped with an electrothermal converter that generates thermal energy.

"Function: In the inkjet recording apparatus of the present invention, a head mounting detection resistor having a predetermined resistance value is connected in parallel to the ink remaining amount detecting element, and the resistance in the ink tank is detected by the ink remaining amount detecting element. The ink resistance in the ink tank changes depending on the amount of ink remaining, so the amount of ink remaining can be determined by detecting the ink resistance. Furthermore, as described above, a head attachment detection resistor is connected in parallel to the ink remaining amount detection element, and the resistance value detected by the ink remaining amount detection element is based on the ink remaining amount as described above. Since the resistor is a composite resistance of the resistor and the head attachment detection resistor, by using the resistance value detected by the remaining ink amount detection element, it is possible to detect the amount of ink remaining and whether or not a cartridge type head is attached. .

According to the second aspect of the present invention, a constant current is applied to the remaining ink amount detection element, and a voltage generated in a combined resistance of the ink resistance and the head attachment detection resistor is set in advance. The amount of remaining ink and the presence or absence of a cartridge-type head are detected by comparing it with a standard voltage value.

[Example] Next, an example of the great invention will be described with reference to the drawings.

In the inkjet recording apparatus of this embodiment, as shown in FIG. It is connected to a part of the drive belt 4 that transmits the driving force, and is slidably attached to two guide shafts 6A and 6B arranged parallel to each other, and the driving force of the drive motor 5 is connected to the drive belt 4. As a result, the inkjet recording head 2 is reciprocated over the entire surface of recording paper, which is a recording medium, fed from a medium feeding device (not shown) to a platen 7 disposed opposite to the ejection surface of the inkjet recording head 2. It is configured to move and perform recording on the recording paper.

As shown in FIG. 2, the inkjet recording head 2 described above has a plurality of thin pipe-shaped head nozzles 12 arranged in parallel to eject ink onto an ejection surface facing the recording surface of a recording paper, and further includes: An ink ejection control element 13 is provided, which is an electrothermal transducer that applies ejection energy to ink supplied from an ink tank integrated into the cartridge type head 1, which will be described later.

In addition, the inkjet recording apparatus of this embodiment has a position where the inkjet recording head 2 is moved during the head recovery operation (the left end of the guide shaft 6A in the figure) outside the range of the reciprocating motion of the inkjet recording head 2 in the recording operation. ,
Hereinafter, this will be referred to as the recovery position. ), the transmission mechanism 11 is arranged opposite to the ejection surface of the inkjet recording head 2.
A head recovery device 8 is provided which includes a cap member 8A that is driven by the driving force of the motor 10 via the inkjet recording head 2 and caps the ejection surface of the inkjet recording head 2.

This head recovery device 8 is provided in the ink suction by an appropriate suction means or ink supply path to the inkjet recording head 2 in connection with the capping of the ejection surface of the inkjet recording head 2 by the cap member 8A during the head recovery operation. An ejection recovery operation is performed, such as removing thickened ink from each head nozzle 12 by forcefully feeding the ink using an appropriate pressure means and forcibly discharging the ink from the head nozzle 12.

Further, on the side surface of the head recovery device 8, a blade 9 as a wiping member made of silicone rubber is held in a cantilever form by a blade holding member 9A.
Similar to the head recovery device 8, the motor lO and the transmission mechanism 1
1, and engagement with the ejection surface of the inkjet recording head 2 becomes possible. As a result, after the ejection recovery operation using the head recovery device 8, the blade 9 is projected into the moving path of the inkjet recording head 2, and as the inkjet recording head 2 moves, the ejection surface of the inkjet recording head 2 is moved. Wipe off any condensation, moisture, or dust.

The above-mentioned inkjet recording apparatus receives data such as document information and control commands manually inputted from the outside by a print control unit, which will be described later, and performs a series of document information recording operations, head recovery operations, etc. in accordance with the received data.

Here, the cartridge type head 1 will be explained with reference to FIG. 3.

This cartridge type head 1 is an integrated ink sponge 14 as an ink tank impregnated with the ink of the inkjet recording heads 2 and 5 described above, and the ink is drawn from the ink sponge 14 by the capillary action of the head nozzle 12. The structure is such that it leads to As described above, the inkjet recording head 2 includes the inkjet control element 13 disposed near the ejection opening of the head nozzle 12, and the inkjet control element 13 is driven by a drive signal IL2 from a print control section to be described later. Then, ink is ejected from each head nozzle 12. Furthermore, two ink remaining amount detection electrodes 15a and 15b are embedded in the ink sponge 14 at an appropriate interval to detect the resistance value of the ink within the ink sponge 14. The resistance value of the ink inside the ink sponge 14 detected by the remaining ink amount detection electrodes 15a and 15b is the same as that of the ink sponge 1.
The amount of ink remaining in the ink sponge 14 can be determined by detecting the resistance value, because the amount of ink impregnated in the ink sponge 14 changes depending on the amount of ink remaining, that is, the amount of ink remaining. moreover,
A head attachment detection resistor 16 having a predetermined resistance value (RO) is connected between the ink remaining amount detection voltages 8i15a and 15b. The above-described ink ejection control element 13 and remaining ink amount detection electrodes 15a and 15b are connected to a print control section via a connector 17.

Next, the above-mentioned printing control section will be explained with reference to FIG. 4.

The print control section 20 shown in FIG. 4 includes a CPU 21 and a ROM 22. It is composed of a RAM 23, an interface circuit 24 for the host device 29, a motor control circuit 25, a head control circuit 26, and a remaining ink amount and head attachment detection circuit 27.

The CPU 21 controls the entire printing operation in the inkjet recording apparatus according to the program and control data stored in advance in the ROM 22, and also controls the remaining amount of ink and a digital signal 2 transferred from the head mounting detection circuit 27, which will be described later. In response to this, it is detected whether the cartridge type head 1 is properly attached or not and the remaining amount of ink. R
The OM 22 is a non-volatile read-only memory, and in addition to storing the program for the CPU 21 to operate as described above, the OM 22 also stores control data necessary for printing operations, and whether the cartridge-type head 1 is installed properly or not. Data that serves as a reference when detecting the remaining amount of ink is stored. R
The AM 23 is a memory from which data can be read and written, and is used as a work area during calculations by the CPU 21 or as a temporary storage area for data input manually from the host device 29 through the interface circuit 24 .

The interface circuit 24 is an interface section for human output of various data between the host device 29 and the inkjet recording apparatus. The motor control circuit 25 drives the drive motor 5 or the motor 10 described above under the control of the CPU 21. The head control circuit 27 supplies a drive signal i1.2 to the ink ejection control element 13 in the inkjet recording head 2 via the connector 28 in accordance with the print data transferred from the CPU 21, and outputs the drive signal from the inkjet recording head 2. The ink is ejected.

The remaining ink amount and head attachment detection circuit 27 is connected to the remaining ink amount detection electrodes 15a and 15b in the cartridge type head 1 via the connector 28, and detects the amount of ink remaining in the cartridge type head 1 and the cartridge. It is detected whether the mold head 1 is mounted on the carriage 3 or not.

Here, the remaining amount of ink in the print control section 20 and the head mounting detection circuit 27 described above will be explained with reference to FIG.

This ink remaining amount and head attachment detection circuit 27 applies a predetermined current i to the ink remaining amount detection electrodes 15a, 15b in the cartridge type head 1 and the head attachment detection resistor 16. a constant current circuit 271 that applies a constant current circuit 271, a buffer amplifier 272 to which the voltage signal IL3 generated by the ink remaining amount detection electrodes 15a, 15b and the head attachment detection resistor 16 is manually input, and an output voltage signal of the buffer amplifier 272. is input and converts the voltage signal into a digital signal 1. A/D converter 273 that converts the data into
It is equipped with Further, at the output section of the constant current circuit 271, at the input terminal of the buffer amplifier 2720, a human resistor 274 with a resistance value of R3 is connected between the input terminal and GND. Therefore, the voltage signal IL3 input to the buffer amplifier 272 has a resistance value (R8) in the ink sponge 14 and a resistor (resistance (a)) for detecting head attachment.
:Ro) 16 and the input resistor (resistance value: R,) 274, the voltage value is generated by the current 10 output from the constant current circuit 271.

Next, the operation of this embodiment will be explained.

First, the principle of determining whether or not the cartridge type head 1 is attached will be explained.

When the cartridge type head 1 is normally mounted on the carriage 3 of the inkjet recording device, the resistance value of the ink resistance between the ink remaining amount detection electrodes 15a and 15b in the ink sponge 14 of the cartridge type head 1 is Assuming R8, the ink resistance (R
), the input resistor (R,) 2, and the head attachment detection resistor (Ro) 16 are connected in parallel to the constant current circuit 271 of the remaining ink amount and head attachment detection circuit 27. , at that time, the buffer amplifier 27 generated by the output current i, [A] from the constant current circuit 271
The 0-point input terminal vA, which is the input terminal of 2, is as follows.

According to the above formula, the amount of ink remaining in the ink sponge 14 is reduced, and the remaining ink amount detection electrode 15a.

It is clear that when the ink resistance (R,') between 15b increases, the input terminal vA also increases, but even if the value of the ink resistance (R,) becomes infinite, this will not be the case. .

Furthermore, when the cartridge type head 1 is removed from the carriage 3, the output current 50 of the constant current circuit 271 will flow only to the human resistor 274 (see Fig. 5), so the voltage at the 0 point is Vc = R*”to[vl.

Here, - VA of the voltage generated at the above-mentioned 0 point, V
It is clear that the magnitude relationship between B and VC is VA<vB<vc, and if the voltage at the 0 point is Va or less, it can be determined that the cartridge type head 1 has been correctly installed in the inkjet recording apparatus. , and Vc, it can be determined that the device is not attached.

Next, the operation of mounting the cartridge type head 1 and detecting the amount of ink remaining in the cartridge type head 1 will be explained along the flowchart of FIG. 6.

First, the voltage signal at the 0 point, which is a detection signal for mounting the cartridge type head 1 and detecting the remaining amount of ink, passes through the buffer amplifier 272 to the A/D converter 273.
The A/D converter 2)3 converts the digital signal 1. After being converted into , it is read into the CPU 21 (
Step 51) When the CPU 21 reads the digital signal β1, the CPU 21 compares the digital signal i with reference voltage data V thl, which is stored in the ROM 22 in advance and serves as a reference for detecting attachment of the cartridge type head 1. to determine whether or not the cartridge type head 1 is attached (step 5).
2).

Here, the reference voltage data V thl is determined by the above-mentioned head-mounted pressure detection resistor (Ro”) 16 and the human resistor (R,) 2.
74 and constant current i. In this embodiment, it is set to . The reason why this Vthl is not equal to VB or VC is that vB and v (respectively, are the lower limits of voltage values that can determine whether or not the cartridge type head 1 is attached,
This is because if the reference value for discrimination is set just below the threshold, it may cause false detection due to noise or error.

As mentioned above, the digital signal fi indicating the voltage value at the 0 point,
As a result of comparing the reference voltage data Vthl with the digital signal 1. If vth8 or more, it is determined that the cartridge type head 1 is not installed, and the CPU 21 sends a cartridge type head not installed code to the host device 29 through the interface circuit 24 and waits for an instruction (step 55).

On the other hand, digital signal 2. If is smaller than vthl, then
It is determined that at least the cartridge type head 1 is attached, and then, as described above, it is compared with the reference voltage data vth2 stored in advance in the ROM 22 (step 53). This V th2 is data for detecting the remaining amount of ink, and when the voltage at the 0 point mentioned above is vA, it corresponds to the remaining ink amount at which a low ink level warning should be issued in response to a decrease in the ink amount. Shows voltage value. Therefore, if the digital signal V, which indicates the voltage value at the 0 point, is lower than the reference voltage data vth2, it is determined that the remaining amount of ink is low, and a remaining ink amount low code is transferred to the host device 29 (step 54).

On the other hand, if the digital signal iLl is equal to or higher than the reference voltage data vth2, it is determined that the remaining amount of ink is appropriate and the printing operation is continued.

In the embodiment described above, voltage detection and comparison were performed using an A/D converter and a CPU, but this could be done using a comparator, etc. equipped with a resistor to which the reference voltage V thl V th2 is set externally. You can make a comparative judgment. Furthermore, instead of using a constant current to detect the resistance value, for example, by using an oscillation circuit to input a pulse signal with a constant period, the CPU detects the change in the frequency of the pulse signal due to the change in the time constant due to the change in the resistance value. It may be detected by Furthermore, the remaining amount of ink may be detected by an optical sensor or the like, and changes in the output of the sensor may be detected. In addition, the remaining amount of ink is detected not only by comparing only with a specific voltage th2.
More precisely, depending on the level of ink remaining,
You may also change your message or behavior.

In the inkjet recording head of this embodiment, the ink ejection control element that provides ejection energy to the ink is not involved in detecting whether or not a cartridge-type head is attached. Any of the electrothermal converters given can be used.

The present invention brings about excellent effects particularly in recording heads and recording apparatuses of the bubble jet method proposed by Canon Co., Ltd. among the ink-shet recording methods.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
By applying at least one drive signal corresponding to recorded information and providing a rapid temperature rise above nucleate boiling, the electrothermal transducer generates thermal energy to cause film boiling on the thermally active surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with this drive signal, which is effective. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one drop. It is more preferable to use this drive signal in the form of a pulse, 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. As this pulse-shaped drive signal, those described in US Pat. No. 4,483,359 and US Pat. No. 4,345,262 are suitable. Note 2. F
US Patent $43 for invention related to temperature and rate of increase of heat recording surface
If the conditions described in the specification of No. 13124 are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combined configuration 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, a heat acting section. US Pat. No. 4,558,333 and US Pat. No. 4,459,600 disclose a configuration in which the
The structure described in the specification may be used. -In addition,
Japanese Unexamined Patent Publication No. 123670 of 1981 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters, and an aperture that absorbs pressure waves of thermal energy is used as a discharge part. The present invention is also effective as a configuration based on Japanese Unexamined Patent Application Publication No. 138461 of 1981, which discloses a configuration corresponding to.

Furthermore, 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 can be increased by combining multiple recording heads as disclosed in the above-mentioned specification. Either a configuration that satisfies the above requirements or a configuration as a single recording head formed integrally may be used, but the present invention can more effectively exhibit the above-mentioned effects.

In addition, a replaceable chip-type recording head that is attached to the device body enables electrical connection to the device body and ink supply from the device body, or a chip-type recording head that is installed integrally with the recording head itself. The present invention is also effective when a cartridge type recording head is used.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. for the recording head, which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specifically, these include pressurizing or suction means for the recording head, preheating means using an electrothermal transducer or heating element other than the stiffener, or a combination thereof, and ejection other than recording. It is also effective to perform a preliminary ejection mode to perform stable printing.

Furthermore, the recording mode of the recording device is not limited to a recording mode of only mainstream colors such as black, but may also include a recording head that is configured integrally or a combination of multiple heads, but can also be a brown color of the color that becomes black, or a mixed color. The present invention is also extremely effective for devices equipped with at least one full color image.

In the embodiments of the present invention described above, the ink is explained as a liquid, but the ink solidifies at room temperature or lower, and becomes soft or liquid at room temperature, or
It may be one that softens or becomes liquid in a temperature range of 30° C. or higher and 70° C. or lower, which is the temperature range generally used for temperature adjustment in ink jets. That is, it is sufficient if the ink is in a liquid state when the recording signal is applied.

In addition, the temperature increase caused by thermal energy can be actively prevented by using it as energy to transform the ink from a solid state to a liquid state, or the ink can be left to solidify while it is left in order to prevent the ink from evaporating. By using
In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal and ejected as liquid ink, or the ink has already begun to solidify by the time it reaches the recording medium. The use of ink that is liquefied is also applicable to the present invention. In such a case, the ink is held in a liquid or solid state in the recesses or through holes of the porous sheet, as described in JP-A-54-56847 or JP-A-60-71260. It may also be in a form that faces 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.

[Effects of the Invention] As explained above, the present invention provides the following effects.

(1) Since the printing operation starts after checking whether the cartridge head is installed, there is no need to start the printing operation without the cartridge head installed, and the amount of ink remaining in the ink tank is also reduced. Since this can be detected, it is possible to avoid printing failures due to ink shortage during printing operations, and the reliability of the recording apparatus is improved.

(2) Since the presence/absence of the cartridge-type head is detected by the remaining ink amount detection means as well as the detection of the remaining amount of ink, the main body of the recording apparatus has only one function for detecting the presence/absence of the cartridge-type head. There is no need to provide a dedicated circuit, the main body of the recording apparatus does not become complicated, and it is economically advantageous.

(3) In the inkjet recording head integrated into the cartridge type head, an ink ejection control element provided in the inkjet recording head that provides ejection energy to the ink detects whether or not the cartridge type head is attached. Since the ink ejection control element is not involved, the selection range of elements used as the ink ejection control element is expanded, and the degree of freedom in designing the cartridge type head is increased.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the inkjet recording apparatus of the present invention, FIG. 2 is a perspective view showing an inkjet recording head, FIG. 3 is a sectional view showing the configuration of a cartridge type head, and FIG. 4 is a print control Block diagram showing the configuration of the fifth section.
The figure is a circuit diagram showing the configuration of the remaining ink amount and head mounting detection circuit, and FIG. 6 is a flowchart showing an example of the operation of the print control section. 1...Cartridge type head 2--Inkjet recording head 3...Carriage 4...Drive belt 5...
- Drive motor 6... Guide shaft 7--Platen 8... Head recovery mechanism 8A... Cap member 9... Blade 9A-- Blade holding member 10-... Motor 11... Transmission mechanism 12-
- Head nozzle 13 - Ink discharge control element 14 - Ink sponge 15 - Ink remaining amount detection electrode 16 - Ink attachment detection resistor 17.28 - Connector 20 - Print control unit 2l −
CPU No. 22-ROM 23-RAM 24-・Interface circuit 25-・Motor control circuit 26-・Head control circuit 27-・Remaining ink amount and head attachment detection circuit 29-・
Host devices 51 to 55 - Step 271 - Constant current circuit 272 - Buffer amplifier 273 - A/D converter 274 - Input resistor

Claims (1)

[Scope of Claims] 1. A cartridge-type head that is removably attached to an inkjet recording apparatus, in which an ink tank, an ink remaining amount detection element that detects the amount of ink remaining in the ink tank, and an inkjet recording head are integrated. In an inkjet recording apparatus comprising a remaining ink amount detection means for detecting a remaining ink amount using detection information from the ink remaining amount detection element, the ink remaining amount detection element detects ink resistance in the ink tank. Further, the cartridge type head includes a head attachment detection resistor having a predetermined resistance value connected in parallel to the ink remaining amount detection element, and the ink remaining amount detection means detects the ink remaining amount. An inkjet recording apparatus characterized in that the remaining amount of ink in the ink tank and whether or not the cartridge-type head is attached are detected using detection information corresponding to a resistance value detected by a detection element. 2. The remaining ink amount detection means includes a power supply circuit that applies a constant current to the remaining ink amount detection element, and a voltage generated in the remaining ink amount detection element by the constant current, which is set in advance.
2. The ink jet recording apparatus according to claim 1, further comprising comparison means for comparing the amount of ink remaining in the ink tank with a reference voltage value indicating the attachment of the cartridge type head. 3. Claim 1 or 2, wherein the inkjet recording head is a full-line type having a plurality of ink ejection ports over the entire recording width of the recording medium.
The inkjet recording device described above. 4. Claim 1, wherein the inkjet recording head discharges ink using thermal energy and is equipped with an electrothermal converter that generates thermal energy.
3. The inkjet recording device according to 2 or 3.